* [RFC PATCH v4 00/13] module: core code clean up
@ 2022-01-30 21:32 Aaron Tomlin
2022-01-30 21:32 ` [RFC PATCH v4 01/13] module: Move all into module/ Aaron Tomlin
` (15 more replies)
0 siblings, 16 replies; 39+ messages in thread
From: Aaron Tomlin @ 2022-01-30 21:32 UTC (permalink / raw)
To: mcgrof
Cc: cl, pmladek, mbenes, akpm, jeyu, linux-kernel, linux-modules,
live-patching, atomlin, ghalat, allen.lkml, void, joe
Hi Luis,
As per your suggestion [1], this is an attempt to refactor and split
optional code out of core module support code into separate components.
This version is based on branch mcgrof/modules-next since a97ac8cb24a3/or
modules-5.17-rc1. Please let me know your thoughts.
Changes since v1 [2]:
- Moved module version support code into a new file
Changes since v2 [3]:
- Moved module decompress support to a separate file
- Made check_modinfo_livepatch() generic (Petr Mladek)
- Removed filename from each newly created file (Luis Chamberlain)
- Addressed some (i.e. --ignore=ASSIGN_IN_IF,AVOID_BUG was used)
minor scripts/checkpatch.pl concerns e.g., use strscpy over
strlcpy and missing a blank line after declarations (Allen)
Changes since v3 [4]:
- Refactored both is_livepatch_module() and set_livepatch_module(),
respectively, to use IS_ENABLED(CONFIG_LIVEPATCH) (Joe Perches)
- Addressed various compiler warnings e.g., no previous prototype (0-day)
[1]: https://lore.kernel.org/lkml/YbEZ4HgSYQEPuRmS@bombadil.infradead.org/
[2]: https://lore.kernel.org/lkml/20211228213041.1356334-1-atomlin@redhat.com/
[3]: https://lore.kernel.org/lkml/20220106234319.2067842-1-atomlin@redhat.com/
[4]: https://lore.kernel.org/lkml/20220128203934.600247-1-atomlin@redhat.com/
Aaron Tomlin (13):
module: Move all into module/
module: Simple refactor in preparation for split
module: Move livepatch support to a separate file
module: Move latched RB-tree support to a separate file
module: Move arch strict rwx support to a separate file
module: Move strict rwx support to a separate file
module: Move extra signature support out of core code
module: Move kmemleak support to a separate file
module: Move kallsyms support into a separate file
module: Move procfs support into a separate file
module: Move sysfs support into a separate file
module: Move kdb_modules list out of core code
module: Move version support into a separate file
MAINTAINERS | 2 +-
include/linux/module.h | 64 +-
kernel/Makefile | 5 +-
kernel/debug/kdb/kdb_main.c | 5 +
kernel/module-internal.h | 50 -
kernel/module/Makefile | 20 +
kernel/module/arch_strict_rwx.c | 44 +
kernel/module/debug_kmemleak.c | 30 +
.../decompress.c} | 2 +-
kernel/module/internal.h | 236 +++
kernel/module/kallsyms.c | 502 +++++
kernel/module/livepatch.c | 74 +
kernel/{module.c => module/main.c} | 1874 +----------------
kernel/module/procfs.c | 142 ++
.../signature.c} | 0
kernel/module/signing.c | 120 ++
kernel/module/strict_rwx.c | 83 +
kernel/module/sysfs.c | 425 ++++
kernel/module/tree_lookup.c | 109 +
kernel/module/version.c | 110 +
kernel/module_signing.c | 45 -
21 files changed, 2038 insertions(+), 1904 deletions(-)
delete mode 100644 kernel/module-internal.h
create mode 100644 kernel/module/Makefile
create mode 100644 kernel/module/arch_strict_rwx.c
create mode 100644 kernel/module/debug_kmemleak.c
rename kernel/{module_decompress.c => module/decompress.c} (99%)
create mode 100644 kernel/module/internal.h
create mode 100644 kernel/module/kallsyms.c
create mode 100644 kernel/module/livepatch.c
rename kernel/{module.c => module/main.c} (63%)
create mode 100644 kernel/module/procfs.c
rename kernel/{module_signature.c => module/signature.c} (100%)
create mode 100644 kernel/module/signing.c
create mode 100644 kernel/module/strict_rwx.c
create mode 100644 kernel/module/sysfs.c
create mode 100644 kernel/module/tree_lookup.c
create mode 100644 kernel/module/version.c
delete mode 100644 kernel/module_signing.c
base-commit: a97ac8cb24a3c3ad74794adb83717ef1605d1b47
--
2.34.1
^ permalink raw reply [flat|nested] 39+ messages in thread
* [RFC PATCH v4 01/13] module: Move all into module/
2022-01-30 21:32 [RFC PATCH v4 00/13] module: core code clean up Aaron Tomlin
@ 2022-01-30 21:32 ` Aaron Tomlin
2022-01-30 21:32 ` [RFC PATCH v4 02/13] module: Simple refactor in preparation for split Aaron Tomlin
` (14 subsequent siblings)
15 siblings, 0 replies; 39+ messages in thread
From: Aaron Tomlin @ 2022-01-30 21:32 UTC (permalink / raw)
To: mcgrof
Cc: cl, pmladek, mbenes, akpm, jeyu, linux-kernel, linux-modules,
live-patching, atomlin, ghalat, allen.lkml, void, joe
No functional changes.
This patch moves all module related code into a separate directory,
modifies each file name and creates a new Makefile. Note: this effort
is in preparation to refactor core module code.
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
MAINTAINERS | 2 +-
kernel/Makefile | 5 +----
kernel/module/Makefile | 9 +++++++++
kernel/{module_decompress.c => module/decompress.c} | 2 +-
kernel/{module-internal.h => module/internal.h} | 0
kernel/{module.c => module/main.c} | 2 +-
kernel/{module_signature.c => module/signature.c} | 0
kernel/{module_signing.c => module/signing.c} | 2 +-
8 files changed, 14 insertions(+), 8 deletions(-)
create mode 100644 kernel/module/Makefile
rename kernel/{module_decompress.c => module/decompress.c} (99%)
rename kernel/{module-internal.h => module/internal.h} (100%)
rename kernel/{module.c => module/main.c} (99%)
rename kernel/{module_signature.c => module/signature.c} (100%)
rename kernel/{module_signing.c => module/signing.c} (97%)
diff --git a/MAINTAINERS b/MAINTAINERS
index acd112c42255..a98f4700acb7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12976,7 +12976,7 @@ L: linux-kernel@vger.kernel.org
S: Maintained
T: git git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux.git modules-next
F: include/linux/module.h
-F: kernel/module.c
+F: kernel/module/main.c
MONOLITHIC POWER SYSTEM PMIC DRIVER
M: Saravanan Sekar <sravanhome@gmail.com>
diff --git a/kernel/Makefile b/kernel/Makefile
index 56f4ee97f328..3a6380975c57 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -53,6 +53,7 @@ obj-y += rcu/
obj-y += livepatch/
obj-y += dma/
obj-y += entry/
+obj-y += module/
obj-$(CONFIG_KCMP) += kcmp.o
obj-$(CONFIG_FREEZER) += freezer.o
@@ -66,10 +67,6 @@ ifneq ($(CONFIG_SMP),y)
obj-y += up.o
endif
obj-$(CONFIG_UID16) += uid16.o
-obj-$(CONFIG_MODULES) += module.o
-obj-$(CONFIG_MODULE_DECOMPRESS) += module_decompress.o
-obj-$(CONFIG_MODULE_SIG) += module_signing.o
-obj-$(CONFIG_MODULE_SIG_FORMAT) += module_signature.o
obj-$(CONFIG_KALLSYMS) += kallsyms.o
obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o
obj-$(CONFIG_CRASH_CORE) += crash_core.o
diff --git a/kernel/module/Makefile b/kernel/module/Makefile
new file mode 100644
index 000000000000..2902fc7d0ef1
--- /dev/null
+++ b/kernel/module/Makefile
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for linux kernel module support
+#
+
+obj-$(CONFIG_MODULES) += main.o
+obj-$(CONFIG_MODULE_DECOMPRESS) += decompress.o
+obj-$(CONFIG_MODULE_SIG) += signing.o
+obj-$(CONFIG_MODULE_SIG_FORMAT) += signature.o
diff --git a/kernel/module_decompress.c b/kernel/module/decompress.c
similarity index 99%
rename from kernel/module_decompress.c
rename to kernel/module/decompress.c
index b01c69c2ff99..c153fd8a4444 100644
--- a/kernel/module_decompress.c
+++ b/kernel/module/decompress.c
@@ -12,7 +12,7 @@
#include <linux/sysfs.h>
#include <linux/vmalloc.h>
-#include "module-internal.h"
+#include "internal.h"
static int module_extend_max_pages(struct load_info *info, unsigned int extent)
{
diff --git a/kernel/module-internal.h b/kernel/module/internal.h
similarity index 100%
rename from kernel/module-internal.h
rename to kernel/module/internal.h
diff --git a/kernel/module.c b/kernel/module/main.c
similarity index 99%
rename from kernel/module.c
rename to kernel/module/main.c
index 387ee77bdbd6..d8c6269af6cf 100644
--- a/kernel/module.c
+++ b/kernel/module/main.c
@@ -58,7 +58,7 @@
#include <linux/dynamic_debug.h>
#include <linux/audit.h>
#include <uapi/linux/module.h>
-#include "module-internal.h"
+#include "internal.h"
#define CREATE_TRACE_POINTS
#include <trace/events/module.h>
diff --git a/kernel/module_signature.c b/kernel/module/signature.c
similarity index 100%
rename from kernel/module_signature.c
rename to kernel/module/signature.c
diff --git a/kernel/module_signing.c b/kernel/module/signing.c
similarity index 97%
rename from kernel/module_signing.c
rename to kernel/module/signing.c
index 8723ae70ea1f..8aeb6d2ee94b 100644
--- a/kernel/module_signing.c
+++ b/kernel/module/signing.c
@@ -12,7 +12,7 @@
#include <linux/string.h>
#include <linux/verification.h>
#include <crypto/public_key.h>
-#include "module-internal.h"
+#include "internal.h"
/*
* Verify the signature on a module.
--
2.34.1
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [RFC PATCH v4 02/13] module: Simple refactor in preparation for split
2022-01-30 21:32 [RFC PATCH v4 00/13] module: core code clean up Aaron Tomlin
2022-01-30 21:32 ` [RFC PATCH v4 01/13] module: Move all into module/ Aaron Tomlin
@ 2022-01-30 21:32 ` Aaron Tomlin
2022-01-30 21:32 ` [RFC PATCH v4 03/13] module: Move livepatch support to a separate file Aaron Tomlin
` (13 subsequent siblings)
15 siblings, 0 replies; 39+ messages in thread
From: Aaron Tomlin @ 2022-01-30 21:32 UTC (permalink / raw)
To: mcgrof
Cc: cl, pmladek, mbenes, akpm, jeyu, linux-kernel, linux-modules,
live-patching, atomlin, ghalat, allen.lkml, void, joe
No functional change.
This patch makes it possible to move non-essential code
out of core module code.
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
kernel/module/internal.h | 22 ++++++++++++++++++++++
kernel/module/main.c | 23 ++---------------------
2 files changed, 24 insertions(+), 21 deletions(-)
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index 8c381c99062f..e3c593f8767f 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -7,6 +7,28 @@
#include <linux/elf.h>
#include <asm/module.h>
+#include <linux/mutex.h>
+
+#ifndef ARCH_SHF_SMALL
+#define ARCH_SHF_SMALL 0
+#endif
+
+/* If this is set, the section belongs in the init part of the module */
+#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
+/* Maximum number of characters written by module_flags() */
+#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
+#define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4))
+
+extern struct mutex module_mutex;
+extern struct list_head modules;
+
+/* Provided by the linker */
+extern const struct kernel_symbol __start___ksymtab[];
+extern const struct kernel_symbol __stop___ksymtab[];
+extern const struct kernel_symbol __start___ksymtab_gpl[];
+extern const struct kernel_symbol __stop___ksymtab_gpl[];
+extern const s32 __start___kcrctab[];
+extern const s32 __start___kcrctab_gpl[];
struct load_info {
const char *name;
diff --git a/kernel/module/main.c b/kernel/module/main.c
index d8c6269af6cf..fee64c4957f3 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -63,10 +63,6 @@
#define CREATE_TRACE_POINTS
#include <trace/events/module.h>
-#ifndef ARCH_SHF_SMALL
-#define ARCH_SHF_SMALL 0
-#endif
-
/*
* Modules' sections will be aligned on page boundaries
* to ensure complete separation of code and data, but
@@ -78,9 +74,6 @@
# define debug_align(X) (X)
#endif
-/* If this is set, the section belongs in the init part of the module */
-#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
-
/*
* Mutex protects:
* 1) List of modules (also safely readable with preempt_disable),
@@ -88,8 +81,8 @@
* 3) module_addr_min/module_addr_max.
* (delete and add uses RCU list operations).
*/
-static DEFINE_MUTEX(module_mutex);
-static LIST_HEAD(modules);
+DEFINE_MUTEX(module_mutex);
+LIST_HEAD(modules);
/* Work queue for freeing init sections in success case */
static void do_free_init(struct work_struct *w);
@@ -408,14 +401,6 @@ static __maybe_unused void *any_section_objs(const struct load_info *info,
return (void *)info->sechdrs[sec].sh_addr;
}
-/* Provided by the linker */
-extern const struct kernel_symbol __start___ksymtab[];
-extern const struct kernel_symbol __stop___ksymtab[];
-extern const struct kernel_symbol __start___ksymtab_gpl[];
-extern const struct kernel_symbol __stop___ksymtab_gpl[];
-extern const s32 __start___kcrctab[];
-extern const s32 __start___kcrctab_gpl[];
-
#ifndef CONFIG_MODVERSIONS
#define symversion(base, idx) NULL
#else
@@ -1490,7 +1475,6 @@ struct module_sect_attrs {
struct module_sect_attr attrs[];
};
-#define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4))
static ssize_t module_sect_read(struct file *file, struct kobject *kobj,
struct bin_attribute *battr,
char *buf, loff_t pos, size_t count)
@@ -4555,9 +4539,6 @@ static void cfi_cleanup(struct module *mod)
#endif
}
-/* Maximum number of characters written by module_flags() */
-#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
-
/* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
static char *module_flags(struct module *mod, char *buf)
{
--
2.34.1
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [RFC PATCH v4 03/13] module: Move livepatch support to a separate file
2022-01-30 21:32 [RFC PATCH v4 00/13] module: core code clean up Aaron Tomlin
2022-01-30 21:32 ` [RFC PATCH v4 01/13] module: Move all into module/ Aaron Tomlin
2022-01-30 21:32 ` [RFC PATCH v4 02/13] module: Simple refactor in preparation for split Aaron Tomlin
@ 2022-01-30 21:32 ` Aaron Tomlin
2022-02-08 11:42 ` Petr Mladek
2022-01-30 21:32 ` [RFC PATCH v4 04/13] module: Move latched RB-tree " Aaron Tomlin
` (12 subsequent siblings)
15 siblings, 1 reply; 39+ messages in thread
From: Aaron Tomlin @ 2022-01-30 21:32 UTC (permalink / raw)
To: mcgrof
Cc: cl, pmladek, mbenes, akpm, jeyu, linux-kernel, linux-modules,
live-patching, atomlin, ghalat, allen.lkml, void, joe
No functional change.
This patch migrates livepatch support (i.e. used during module
add/or load and remove/or deletion) from core module code into
kernel/module/livepatch.c. At the moment it contains code to
persist Elf information about a given livepatch module, only.
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
include/linux/module.h | 16 ++++--
kernel/module/Makefile | 3 ++
kernel/module/internal.h | 11 ++++
kernel/module/livepatch.c | 74 +++++++++++++++++++++++++++
kernel/module/main.c | 102 ++++----------------------------------
5 files changed, 109 insertions(+), 97 deletions(-)
create mode 100644 kernel/module/livepatch.c
diff --git a/include/linux/module.h b/include/linux/module.h
index f4338235ed2c..c7daac4d16ee 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -663,17 +663,23 @@ static inline bool module_requested_async_probing(struct module *module)
return module && module->async_probe_requested;
}
-#ifdef CONFIG_LIVEPATCH
static inline bool is_livepatch_module(struct module *mod)
{
- return mod->klp;
+ if (IS_ENABLED(CONFIG_LIVEPATCH)) {
+ if (mod->klp)
+ return true;
+ }
+ return false;
}
-#else /* !CONFIG_LIVEPATCH */
-static inline bool is_livepatch_module(struct module *mod)
+
+static inline bool set_livepatch_module(struct module *mod)
{
+ if (IS_ENABLED(CONFIG_LIVEPATCH)) {
+ mod->klp = true;
+ return true;
+ }
return false;
}
-#endif /* CONFIG_LIVEPATCH */
bool is_module_sig_enforced(void);
void set_module_sig_enforced(void);
diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index 2902fc7d0ef1..ee20d864ad19 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -7,3 +7,6 @@ obj-$(CONFIG_MODULES) += main.o
obj-$(CONFIG_MODULE_DECOMPRESS) += decompress.o
obj-$(CONFIG_MODULE_SIG) += signing.o
obj-$(CONFIG_MODULE_SIG_FORMAT) += signature.o
+ifdef CONFIG_MODULES
+obj-$(CONFIG_LIVEPATCH) += livepatch.o
+endif
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index e3c593f8767f..6150ec5ae042 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -57,6 +57,17 @@ struct load_info {
extern int mod_verify_sig(const void *mod, struct load_info *info);
+#ifdef CONFIG_LIVEPATCH
+extern int copy_module_elf(struct module *mod, struct load_info *info);
+extern void free_module_elf(struct module *mod);
+#else /* !CONFIG_LIVEPATCH */
+static inline int copy_module_elf(struct module *mod, struct load_info *info)
+{
+ return 0;
+}
+static inline void free_module_elf(struct module *mod) { }
+#endif /* CONFIG_LIVEPATCH */
+
#ifdef CONFIG_MODULE_DECOMPRESS
int module_decompress(struct load_info *info, const void *buf, size_t size);
void module_decompress_cleanup(struct load_info *info);
diff --git a/kernel/module/livepatch.c b/kernel/module/livepatch.c
new file mode 100644
index 000000000000..961045d32332
--- /dev/null
+++ b/kernel/module/livepatch.c
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Module livepatch support
+ *
+ * Copyright (C) 2016 Jessica Yu <jeyu@redhat.com>
+ */
+
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include "internal.h"
+
+/*
+ * Persist Elf information about a module. Copy the Elf header,
+ * section header table, section string table, and symtab section
+ * index from info to mod->klp_info.
+ */
+int copy_module_elf(struct module *mod, struct load_info *info)
+{
+ unsigned int size, symndx;
+ int ret;
+
+ size = sizeof(*mod->klp_info);
+ mod->klp_info = kmalloc(size, GFP_KERNEL);
+ if (mod->klp_info == NULL)
+ return -ENOMEM;
+
+ /* Elf header */
+ size = sizeof(mod->klp_info->hdr);
+ memcpy(&mod->klp_info->hdr, info->hdr, size);
+
+ /* Elf section header table */
+ size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
+ mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL);
+ if (mod->klp_info->sechdrs == NULL) {
+ ret = -ENOMEM;
+ goto free_info;
+ }
+
+ /* Elf section name string table */
+ size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
+ mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL);
+ if (mod->klp_info->secstrings == NULL) {
+ ret = -ENOMEM;
+ goto free_sechdrs;
+ }
+
+ /* Elf symbol section index */
+ symndx = info->index.sym;
+ mod->klp_info->symndx = symndx;
+
+ /*
+ * For livepatch modules, core_kallsyms.symtab is a complete
+ * copy of the original symbol table. Adjust sh_addr to point
+ * to core_kallsyms.symtab since the copy of the symtab in module
+ * init memory is freed at the end of do_init_module().
+ */
+ mod->klp_info->sechdrs[symndx].sh_addr = (unsigned long) mod->core_kallsyms.symtab;
+
+ return 0;
+
+free_sechdrs:
+ kfree(mod->klp_info->sechdrs);
+free_info:
+ kfree(mod->klp_info);
+ return ret;
+}
+
+void free_module_elf(struct module *mod)
+{
+ kfree(mod->klp_info->sechdrs);
+ kfree(mod->klp_info->secstrings);
+ kfree(mod->klp_info);
+}
diff --git a/kernel/module/main.c b/kernel/module/main.c
index fee64c4957f3..c91c7e57bca7 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -2042,81 +2042,6 @@ static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
}
#endif /* CONFIG_STRICT_MODULE_RWX */
-#ifdef CONFIG_LIVEPATCH
-/*
- * Persist Elf information about a module. Copy the Elf header,
- * section header table, section string table, and symtab section
- * index from info to mod->klp_info.
- */
-static int copy_module_elf(struct module *mod, struct load_info *info)
-{
- unsigned int size, symndx;
- int ret;
-
- size = sizeof(*mod->klp_info);
- mod->klp_info = kmalloc(size, GFP_KERNEL);
- if (mod->klp_info == NULL)
- return -ENOMEM;
-
- /* Elf header */
- size = sizeof(mod->klp_info->hdr);
- memcpy(&mod->klp_info->hdr, info->hdr, size);
-
- /* Elf section header table */
- size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
- mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL);
- if (mod->klp_info->sechdrs == NULL) {
- ret = -ENOMEM;
- goto free_info;
- }
-
- /* Elf section name string table */
- size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
- mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL);
- if (mod->klp_info->secstrings == NULL) {
- ret = -ENOMEM;
- goto free_sechdrs;
- }
-
- /* Elf symbol section index */
- symndx = info->index.sym;
- mod->klp_info->symndx = symndx;
-
- /*
- * For livepatch modules, core_kallsyms.symtab is a complete
- * copy of the original symbol table. Adjust sh_addr to point
- * to core_kallsyms.symtab since the copy of the symtab in module
- * init memory is freed at the end of do_init_module().
- */
- mod->klp_info->sechdrs[symndx].sh_addr = \
- (unsigned long) mod->core_kallsyms.symtab;
-
- return 0;
-
-free_sechdrs:
- kfree(mod->klp_info->sechdrs);
-free_info:
- kfree(mod->klp_info);
- return ret;
-}
-
-static void free_module_elf(struct module *mod)
-{
- kfree(mod->klp_info->sechdrs);
- kfree(mod->klp_info->secstrings);
- kfree(mod->klp_info);
-}
-#else /* !CONFIG_LIVEPATCH */
-static int copy_module_elf(struct module *mod, struct load_info *info)
-{
- return 0;
-}
-
-static void free_module_elf(struct module *mod)
-{
-}
-#endif /* CONFIG_LIVEPATCH */
-
void __weak module_memfree(void *module_region)
{
/*
@@ -3091,30 +3016,23 @@ static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned l
return 0;
}
-#ifdef CONFIG_LIVEPATCH
static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
{
- if (get_modinfo(info, "livepatch")) {
- mod->klp = true;
+ if (!get_modinfo(info, "livepatch"))
+ /* Nothing more to do */
+ return 0;
+
+ if (set_livepatch_module(mod)) {
add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
- mod->name);
- }
-
- return 0;
-}
-#else /* !CONFIG_LIVEPATCH */
-static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
-{
- if (get_modinfo(info, "livepatch")) {
- pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
- mod->name);
- return -ENOEXEC;
+ mod->name);
+ return 0;
}
- return 0;
+ pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
+ mod->name);
+ return -ENOEXEC;
}
-#endif /* CONFIG_LIVEPATCH */
static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
{
--
2.34.1
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [RFC PATCH v4 04/13] module: Move latched RB-tree support to a separate file
2022-01-30 21:32 [RFC PATCH v4 00/13] module: core code clean up Aaron Tomlin
` (2 preceding siblings ...)
2022-01-30 21:32 ` [RFC PATCH v4 03/13] module: Move livepatch support to a separate file Aaron Tomlin
@ 2022-01-30 21:32 ` Aaron Tomlin
2022-01-30 21:32 ` [RFC PATCH v4 05/13] module: Move arch strict rwx " Aaron Tomlin
` (11 subsequent siblings)
15 siblings, 0 replies; 39+ messages in thread
From: Aaron Tomlin @ 2022-01-30 21:32 UTC (permalink / raw)
To: mcgrof
Cc: cl, pmladek, mbenes, akpm, jeyu, linux-kernel, linux-modules,
live-patching, atomlin, ghalat, allen.lkml, void, joe
No functional change.
This patch migrates module latched RB-tree support
(e.g. see __module_address()) from core module code
into kernel/module/tree_lookup.c.
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
include/linux/module.h | 4 +-
kernel/module/Makefile | 1 +
kernel/module/internal.h | 33 +++++++++
kernel/module/main.c | 129 +-----------------------------------
kernel/module/tree_lookup.c | 109 ++++++++++++++++++++++++++++++
5 files changed, 147 insertions(+), 129 deletions(-)
create mode 100644 kernel/module/tree_lookup.c
diff --git a/include/linux/module.h b/include/linux/module.h
index c7daac4d16ee..faeb7ae49b89 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -342,9 +342,9 @@ struct module_layout {
#ifdef CONFIG_MODULES_TREE_LOOKUP
/* Only touch one cacheline for common rbtree-for-core-layout case. */
#define __module_layout_align ____cacheline_aligned
-#else
+#else /* !CONFIG_MODULES_TREE_LOOKUP */
#define __module_layout_align
-#endif
+#endif /* CONFIG_MODULES_TREE_LOOKUP */
struct mod_kallsyms {
Elf_Sym *symtab;
diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index ee20d864ad19..fc6d7a053a62 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -9,4 +9,5 @@ obj-$(CONFIG_MODULE_SIG) += signing.o
obj-$(CONFIG_MODULE_SIG_FORMAT) += signature.o
ifdef CONFIG_MODULES
obj-$(CONFIG_LIVEPATCH) += livepatch.o
+obj-$(CONFIG_MODULES_TREE_LOOKUP) += tree_lookup.o
endif
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index 6150ec5ae042..de28d6bb7b5b 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -81,3 +81,36 @@ static inline void module_decompress_cleanup(struct load_info *info)
{
}
#endif
+
+#ifdef CONFIG_MODULES_TREE_LOOKUP
+struct mod_tree_root {
+ struct latch_tree_root root;
+ unsigned long addr_min;
+ unsigned long addr_max;
+};
+
+extern struct mod_tree_root mod_tree;
+
+extern void mod_tree_insert(struct module *mod);
+extern void mod_tree_remove_init(struct module *mod);
+extern void mod_tree_remove(struct module *mod);
+extern struct module *mod_find(unsigned long addr);
+#else /* !CONFIG_MODULES_TREE_LOOKUP */
+static unsigned long module_addr_min = -1UL, module_addr_max = 0;
+
+static void mod_tree_insert(struct module *mod) { }
+static void mod_tree_remove_init(struct module *mod) { }
+static void mod_tree_remove(struct module *mod) { }
+static struct module *mod_find(unsigned long addr)
+{
+ struct module *mod;
+
+ list_for_each_entry_rcu(mod, &modules, list,
+ lockdep_is_held(&module_mutex)) {
+ if (within_module(addr, mod))
+ return mod;
+ }
+
+ return NULL;
+}
+#endif /* CONFIG_MODULES_TREE_LOOKUP */
diff --git a/kernel/module/main.c b/kernel/module/main.c
index c91c7e57bca7..941be7788626 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -90,138 +90,13 @@ static DECLARE_WORK(init_free_wq, do_free_init);
static LLIST_HEAD(init_free_list);
#ifdef CONFIG_MODULES_TREE_LOOKUP
-
-/*
- * Use a latched RB-tree for __module_address(); this allows us to use
- * RCU-sched lookups of the address from any context.
- *
- * This is conditional on PERF_EVENTS || TRACING because those can really hit
- * __module_address() hard by doing a lot of stack unwinding; potentially from
- * NMI context.
- */
-
-static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
-{
- struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
-
- return (unsigned long)layout->base;
-}
-
-static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
-{
- struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
-
- return (unsigned long)layout->size;
-}
-
-static __always_inline bool
-mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
-{
- return __mod_tree_val(a) < __mod_tree_val(b);
-}
-
-static __always_inline int
-mod_tree_comp(void *key, struct latch_tree_node *n)
-{
- unsigned long val = (unsigned long)key;
- unsigned long start, end;
-
- start = __mod_tree_val(n);
- if (val < start)
- return -1;
-
- end = start + __mod_tree_size(n);
- if (val >= end)
- return 1;
-
- return 0;
-}
-
-static const struct latch_tree_ops mod_tree_ops = {
- .less = mod_tree_less,
- .comp = mod_tree_comp,
-};
-
-static struct mod_tree_root {
- struct latch_tree_root root;
- unsigned long addr_min;
- unsigned long addr_max;
-} mod_tree __cacheline_aligned = {
+struct mod_tree_root mod_tree __cacheline_aligned = {
.addr_min = -1UL,
};
#define module_addr_min mod_tree.addr_min
#define module_addr_max mod_tree.addr_max
-
-static noinline void __mod_tree_insert(struct mod_tree_node *node)
-{
- latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
-}
-
-static void __mod_tree_remove(struct mod_tree_node *node)
-{
- latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
-}
-
-/*
- * These modifications: insert, remove_init and remove; are serialized by the
- * module_mutex.
- */
-static void mod_tree_insert(struct module *mod)
-{
- mod->core_layout.mtn.mod = mod;
- mod->init_layout.mtn.mod = mod;
-
- __mod_tree_insert(&mod->core_layout.mtn);
- if (mod->init_layout.size)
- __mod_tree_insert(&mod->init_layout.mtn);
-}
-
-static void mod_tree_remove_init(struct module *mod)
-{
- if (mod->init_layout.size)
- __mod_tree_remove(&mod->init_layout.mtn);
-}
-
-static void mod_tree_remove(struct module *mod)
-{
- __mod_tree_remove(&mod->core_layout.mtn);
- mod_tree_remove_init(mod);
-}
-
-static struct module *mod_find(unsigned long addr)
-{
- struct latch_tree_node *ltn;
-
- ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
- if (!ltn)
- return NULL;
-
- return container_of(ltn, struct mod_tree_node, node)->mod;
-}
-
-#else /* MODULES_TREE_LOOKUP */
-
-static unsigned long module_addr_min = -1UL, module_addr_max = 0;
-
-static void mod_tree_insert(struct module *mod) { }
-static void mod_tree_remove_init(struct module *mod) { }
-static void mod_tree_remove(struct module *mod) { }
-
-static struct module *mod_find(unsigned long addr)
-{
- struct module *mod;
-
- list_for_each_entry_rcu(mod, &modules, list,
- lockdep_is_held(&module_mutex)) {
- if (within_module(addr, mod))
- return mod;
- }
-
- return NULL;
-}
-
-#endif /* MODULES_TREE_LOOKUP */
+#endif
/*
* Bounds of module text, for speeding up __module_address.
diff --git a/kernel/module/tree_lookup.c b/kernel/module/tree_lookup.c
new file mode 100644
index 000000000000..037d6eb2f56f
--- /dev/null
+++ b/kernel/module/tree_lookup.c
@@ -0,0 +1,109 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Modules tree lookup
+ *
+ * Copyright (C) 2015 Peter Zijlstra
+ * Copyright (C) 2015 Rusty Russell
+ */
+
+#include <linux/module.h>
+#include <linux/rbtree_latch.h>
+#include "internal.h"
+
+/*
+ * Use a latched RB-tree for __module_address(); this allows us to use
+ * RCU-sched lookups of the address from any context.
+ *
+ * This is conditional on PERF_EVENTS || TRACING because those can really hit
+ * __module_address() hard by doing a lot of stack unwinding; potentially from
+ * NMI context.
+ */
+
+__always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
+{
+ struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
+
+ return (unsigned long)layout->base;
+}
+
+__always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
+{
+ struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
+
+ return (unsigned long)layout->size;
+}
+
+__always_inline bool
+mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
+{
+ return __mod_tree_val(a) < __mod_tree_val(b);
+}
+
+__always_inline int
+mod_tree_comp(void *key, struct latch_tree_node *n)
+{
+ unsigned long val = (unsigned long)key;
+ unsigned long start, end;
+
+ start = __mod_tree_val(n);
+ if (val < start)
+ return -1;
+
+ end = start + __mod_tree_size(n);
+ if (val >= end)
+ return 1;
+
+ return 0;
+}
+
+const struct latch_tree_ops mod_tree_ops = {
+ .less = mod_tree_less,
+ .comp = mod_tree_comp,
+};
+
+static noinline void __mod_tree_insert(struct mod_tree_node *node)
+{
+ latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
+}
+
+static void __mod_tree_remove(struct mod_tree_node *node)
+{
+ latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
+}
+
+/*
+ * These modifications: insert, remove_init and remove; are serialized by the
+ * module_mutex.
+ */
+void mod_tree_insert(struct module *mod)
+{
+ mod->core_layout.mtn.mod = mod;
+ mod->init_layout.mtn.mod = mod;
+
+ __mod_tree_insert(&mod->core_layout.mtn);
+ if (mod->init_layout.size)
+ __mod_tree_insert(&mod->init_layout.mtn);
+}
+
+void mod_tree_remove_init(struct module *mod)
+{
+ if (mod->init_layout.size)
+ __mod_tree_remove(&mod->init_layout.mtn);
+}
+
+void mod_tree_remove(struct module *mod)
+{
+ __mod_tree_remove(&mod->core_layout.mtn);
+ mod_tree_remove_init(mod);
+}
+
+struct module *mod_find(unsigned long addr)
+{
+ struct latch_tree_node *ltn;
+
+ ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
+ if (!ltn)
+ return NULL;
+
+ return container_of(ltn, struct mod_tree_node, node)->mod;
+}
--
2.34.1
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [RFC PATCH v4 05/13] module: Move arch strict rwx support to a separate file
2022-01-30 21:32 [RFC PATCH v4 00/13] module: core code clean up Aaron Tomlin
` (3 preceding siblings ...)
2022-01-30 21:32 ` [RFC PATCH v4 04/13] module: Move latched RB-tree " Aaron Tomlin
@ 2022-01-30 21:32 ` Aaron Tomlin
2022-01-30 21:32 ` [RFC PATCH v4 06/13] module: Move " Aaron Tomlin
` (10 subsequent siblings)
15 siblings, 0 replies; 39+ messages in thread
From: Aaron Tomlin @ 2022-01-30 21:32 UTC (permalink / raw)
To: mcgrof
Cc: cl, pmladek, mbenes, akpm, jeyu, linux-kernel, linux-modules,
live-patching, atomlin, ghalat, allen.lkml, void, joe
No functional change.
This patch migrates applicable architecture code
that support strict module rwx from core module code
into kernel/module/arch_strict_rwx.c
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
include/linux/module.h | 17 +++++++++++
kernel/module/Makefile | 1 +
kernel/module/arch_strict_rwx.c | 44 ++++++++++++++++++++++++++++
kernel/module/main.c | 51 ---------------------------------
4 files changed, 62 insertions(+), 51 deletions(-)
create mode 100644 kernel/module/arch_strict_rwx.c
diff --git a/include/linux/module.h b/include/linux/module.h
index faeb7ae49b89..8b75380bc340 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -339,6 +339,23 @@ struct module_layout {
#endif
};
+/*
+ * Modules' sections will be aligned on page boundaries
+ * to ensure complete separation of code and data, but
+ * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y
+ */
+#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
+# define debug_align(X) ALIGN(X, PAGE_SIZE)
+
+extern void frob_text(const struct module_layout *layout,
+ int (*set_memory)(unsigned long start, int num_pages));
+extern void module_enable_x(const struct module *mod);
+#else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
+# define debug_align(X) (X)
+
+static void module_enable_x(const struct module *mod) { }
+#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
+
#ifdef CONFIG_MODULES_TREE_LOOKUP
/* Only touch one cacheline for common rbtree-for-core-layout case. */
#define __module_layout_align ____cacheline_aligned
diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index fc6d7a053a62..146509978708 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -10,4 +10,5 @@ obj-$(CONFIG_MODULE_SIG_FORMAT) += signature.o
ifdef CONFIG_MODULES
obj-$(CONFIG_LIVEPATCH) += livepatch.o
obj-$(CONFIG_MODULES_TREE_LOOKUP) += tree_lookup.o
+obj-$(CONFIG_ARCH_HAS_STRICT_MODULE_RWX) += arch_strict_rwx.o
endif
diff --git a/kernel/module/arch_strict_rwx.c b/kernel/module/arch_strict_rwx.c
new file mode 100644
index 000000000000..9801cb4fef36
--- /dev/null
+++ b/kernel/module/arch_strict_rwx.c
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Module arch strict rwx
+ *
+ * Copyright (C) 2015 Rusty Russell
+ */
+
+#include <linux/module.h>
+#include <linux/set_memory.h>
+
+/*
+ * LKM RO/NX protection: protect module's text/ro-data
+ * from modification and any data from execution.
+ *
+ * General layout of module is:
+ * [text] [read-only-data] [ro-after-init] [writable data]
+ * text_size -----^ ^ ^ ^
+ * ro_size ------------------------| | |
+ * ro_after_init_size -----------------------------| |
+ * size -----------------------------------------------------------|
+ *
+ * These values are always page-aligned (as is base)
+ */
+
+/*
+ * Since some arches are moving towards PAGE_KERNEL module allocations instead
+ * of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() outside of the
+ * CONFIG_STRICT_MODULE_RWX block below because they are needed regardless of
+ * whether we are strict.
+ */
+void frob_text(const struct module_layout *layout,
+ int (*set_memory)(unsigned long start, int num_pages))
+{
+ BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
+ BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
+ set_memory((unsigned long)layout->base,
+ layout->text_size >> PAGE_SHIFT);
+}
+
+void module_enable_x(const struct module *mod)
+{
+ frob_text(&mod->core_layout, set_memory_x);
+ frob_text(&mod->init_layout, set_memory_x);
+}
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 941be7788626..7e98ea12b146 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -13,7 +13,6 @@
#include <linux/trace_events.h>
#include <linux/init.h>
#include <linux/kallsyms.h>
-#include <linux/buildid.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/sysfs.h>
@@ -63,17 +62,6 @@
#define CREATE_TRACE_POINTS
#include <trace/events/module.h>
-/*
- * Modules' sections will be aligned on page boundaries
- * to ensure complete separation of code and data, but
- * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y
- */
-#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
-# define debug_align(X) ALIGN(X, PAGE_SIZE)
-#else
-# define debug_align(X) (X)
-#endif
-
/*
* Mutex protects:
* 1) List of modules (also safely readable with preempt_disable),
@@ -1794,45 +1782,6 @@ static void mod_sysfs_teardown(struct module *mod)
mod_sysfs_fini(mod);
}
-/*
- * LKM RO/NX protection: protect module's text/ro-data
- * from modification and any data from execution.
- *
- * General layout of module is:
- * [text] [read-only-data] [ro-after-init] [writable data]
- * text_size -----^ ^ ^ ^
- * ro_size ------------------------| | |
- * ro_after_init_size -----------------------------| |
- * size -----------------------------------------------------------|
- *
- * These values are always page-aligned (as is base)
- */
-
-/*
- * Since some arches are moving towards PAGE_KERNEL module allocations instead
- * of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() outside of the
- * CONFIG_STRICT_MODULE_RWX block below because they are needed regardless of
- * whether we are strict.
- */
-#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
-static void frob_text(const struct module_layout *layout,
- int (*set_memory)(unsigned long start, int num_pages))
-{
- BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
- BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
- set_memory((unsigned long)layout->base,
- layout->text_size >> PAGE_SHIFT);
-}
-
-static void module_enable_x(const struct module *mod)
-{
- frob_text(&mod->core_layout, set_memory_x);
- frob_text(&mod->init_layout, set_memory_x);
-}
-#else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
-static void module_enable_x(const struct module *mod) { }
-#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
-
#ifdef CONFIG_STRICT_MODULE_RWX
static void frob_rodata(const struct module_layout *layout,
int (*set_memory)(unsigned long start, int num_pages))
--
2.34.1
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [RFC PATCH v4 06/13] module: Move strict rwx support to a separate file
2022-01-30 21:32 [RFC PATCH v4 00/13] module: core code clean up Aaron Tomlin
` (4 preceding siblings ...)
2022-01-30 21:32 ` [RFC PATCH v4 05/13] module: Move arch strict rwx " Aaron Tomlin
@ 2022-01-30 21:32 ` Aaron Tomlin
2022-01-30 21:32 ` [RFC PATCH v4 07/13] module: Move extra signature support out of core code Aaron Tomlin
` (9 subsequent siblings)
15 siblings, 0 replies; 39+ messages in thread
From: Aaron Tomlin @ 2022-01-30 21:32 UTC (permalink / raw)
To: mcgrof
Cc: cl, pmladek, mbenes, akpm, jeyu, linux-kernel, linux-modules,
live-patching, atomlin, ghalat, allen.lkml, void, joe
No functional change.
This patch migrates code that makes module text
and rodata memory read-only and non-text memory
non-executable from core module code into
kernel/module/strict_rwx.c.
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
include/linux/module.h | 22 ++++++++++
kernel/module/Makefile | 1 +
kernel/module/main.c | 84 --------------------------------------
kernel/module/strict_rwx.c | 83 +++++++++++++++++++++++++++++++++++++
4 files changed, 106 insertions(+), 84 deletions(-)
create mode 100644 kernel/module/strict_rwx.c
diff --git a/include/linux/module.h b/include/linux/module.h
index 8b75380bc340..520c0f4bb968 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -356,6 +356,28 @@ extern void module_enable_x(const struct module *mod);
static void module_enable_x(const struct module *mod) { }
#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
+#ifdef CONFIG_STRICT_MODULE_RWX
+extern void frob_rodata(const struct module_layout *layout,
+ int (*set_memory)(unsigned long start, int num_pages));
+extern void frob_ro_after_init(const struct module_layout *layout,
+ int (*set_memory)(unsigned long start, int num_pages));
+extern void frob_writable_data(const struct module_layout *layout,
+ int (*set_memory)(unsigned long start, int num_pages));
+extern void module_enable_ro(const struct module *mod, bool after_init);
+extern void module_enable_nx(const struct module *mod);
+extern int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
+ char *secstrings, struct module *mod);
+
+#else /* !CONFIG_STRICT_MODULE_RWX */
+static void module_enable_nx(const struct module *mod) { }
+static void module_enable_ro(const struct module *mod, bool after_init) {}
+static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
+ char *secstrings, struct module *mod)
+{
+ return 0;
+}
+#endif /* CONFIG_STRICT_MODULE_RWX */
+
#ifdef CONFIG_MODULES_TREE_LOOKUP
/* Only touch one cacheline for common rbtree-for-core-layout case. */
#define __module_layout_align ____cacheline_aligned
diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index 146509978708..d1dada641ad6 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -11,4 +11,5 @@ ifdef CONFIG_MODULES
obj-$(CONFIG_LIVEPATCH) += livepatch.o
obj-$(CONFIG_MODULES_TREE_LOOKUP) += tree_lookup.o
obj-$(CONFIG_ARCH_HAS_STRICT_MODULE_RWX) += arch_strict_rwx.o
+obj-$(CONFIG_STRICT_MODULE_RWX) += strict_rwx.o
endif
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 7e98ea12b146..1a0e659a27bc 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -1782,90 +1782,6 @@ static void mod_sysfs_teardown(struct module *mod)
mod_sysfs_fini(mod);
}
-#ifdef CONFIG_STRICT_MODULE_RWX
-static void frob_rodata(const struct module_layout *layout,
- int (*set_memory)(unsigned long start, int num_pages))
-{
- BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
- BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
- BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
- set_memory((unsigned long)layout->base + layout->text_size,
- (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
-}
-
-static void frob_ro_after_init(const struct module_layout *layout,
- int (*set_memory)(unsigned long start, int num_pages))
-{
- BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
- BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
- BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
- set_memory((unsigned long)layout->base + layout->ro_size,
- (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
-}
-
-static void frob_writable_data(const struct module_layout *layout,
- int (*set_memory)(unsigned long start, int num_pages))
-{
- BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
- BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
- BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
- set_memory((unsigned long)layout->base + layout->ro_after_init_size,
- (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
-}
-
-static void module_enable_ro(const struct module *mod, bool after_init)
-{
- if (!rodata_enabled)
- return;
-
- set_vm_flush_reset_perms(mod->core_layout.base);
- set_vm_flush_reset_perms(mod->init_layout.base);
- frob_text(&mod->core_layout, set_memory_ro);
-
- frob_rodata(&mod->core_layout, set_memory_ro);
- frob_text(&mod->init_layout, set_memory_ro);
- frob_rodata(&mod->init_layout, set_memory_ro);
-
- if (after_init)
- frob_ro_after_init(&mod->core_layout, set_memory_ro);
-}
-
-static void module_enable_nx(const struct module *mod)
-{
- frob_rodata(&mod->core_layout, set_memory_nx);
- frob_ro_after_init(&mod->core_layout, set_memory_nx);
- frob_writable_data(&mod->core_layout, set_memory_nx);
- frob_rodata(&mod->init_layout, set_memory_nx);
- frob_writable_data(&mod->init_layout, set_memory_nx);
-}
-
-static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
- char *secstrings, struct module *mod)
-{
- const unsigned long shf_wx = SHF_WRITE|SHF_EXECINSTR;
- int i;
-
- for (i = 0; i < hdr->e_shnum; i++) {
- if ((sechdrs[i].sh_flags & shf_wx) == shf_wx) {
- pr_err("%s: section %s (index %d) has invalid WRITE|EXEC flags\n",
- mod->name, secstrings + sechdrs[i].sh_name, i);
- return -ENOEXEC;
- }
- }
-
- return 0;
-}
-
-#else /* !CONFIG_STRICT_MODULE_RWX */
-static void module_enable_nx(const struct module *mod) { }
-static void module_enable_ro(const struct module *mod, bool after_init) {}
-static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
- char *secstrings, struct module *mod)
-{
- return 0;
-}
-#endif /* CONFIG_STRICT_MODULE_RWX */
-
void __weak module_memfree(void *module_region)
{
/*
diff --git a/kernel/module/strict_rwx.c b/kernel/module/strict_rwx.c
new file mode 100644
index 000000000000..39060021755a
--- /dev/null
+++ b/kernel/module/strict_rwx.c
@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Module strict rwx
+ *
+ * Copyright (C) 2015 Rusty Russell
+ */
+
+#include <linux/module.h>
+#include <linux/vmalloc.h>
+#include <linux/set_memory.h>
+
+void frob_rodata(const struct module_layout *layout,
+ int (*set_memory)(unsigned long start, int num_pages))
+{
+ BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
+ BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
+ BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
+ set_memory((unsigned long)layout->base + layout->text_size,
+ (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
+}
+
+void frob_ro_after_init(const struct module_layout *layout,
+ int (*set_memory)(unsigned long start, int num_pages))
+{
+ BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
+ BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
+ BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
+ set_memory((unsigned long)layout->base + layout->ro_size,
+ (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
+}
+
+void frob_writable_data(const struct module_layout *layout,
+ int (*set_memory)(unsigned long start, int num_pages))
+{
+ BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
+ BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
+ BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
+ set_memory((unsigned long)layout->base + layout->ro_after_init_size,
+ (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
+}
+
+void module_enable_ro(const struct module *mod, bool after_init)
+{
+ if (!rodata_enabled)
+ return;
+
+ set_vm_flush_reset_perms(mod->core_layout.base);
+ set_vm_flush_reset_perms(mod->init_layout.base);
+ frob_text(&mod->core_layout, set_memory_ro);
+
+ frob_rodata(&mod->core_layout, set_memory_ro);
+ frob_text(&mod->init_layout, set_memory_ro);
+ frob_rodata(&mod->init_layout, set_memory_ro);
+
+ if (after_init)
+ frob_ro_after_init(&mod->core_layout, set_memory_ro);
+}
+
+void module_enable_nx(const struct module *mod)
+{
+ frob_rodata(&mod->core_layout, set_memory_nx);
+ frob_ro_after_init(&mod->core_layout, set_memory_nx);
+ frob_writable_data(&mod->core_layout, set_memory_nx);
+ frob_rodata(&mod->init_layout, set_memory_nx);
+ frob_writable_data(&mod->init_layout, set_memory_nx);
+}
+
+int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
+ char *secstrings, struct module *mod)
+{
+ const unsigned long shf_wx = SHF_WRITE|SHF_EXECINSTR;
+ int i;
+
+ for (i = 0; i < hdr->e_shnum; i++) {
+ if ((sechdrs[i].sh_flags & shf_wx) == shf_wx) {
+ pr_err("%s: section %s (index %d) has invalid WRITE|EXEC flags\n",
+ mod->name, secstrings + sechdrs[i].sh_name, i);
+ return -ENOEXEC;
+ }
+ }
+
+ return 0;
+}
--
2.34.1
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [RFC PATCH v4 07/13] module: Move extra signature support out of core code
2022-01-30 21:32 [RFC PATCH v4 00/13] module: core code clean up Aaron Tomlin
` (5 preceding siblings ...)
2022-01-30 21:32 ` [RFC PATCH v4 06/13] module: Move " Aaron Tomlin
@ 2022-01-30 21:32 ` Aaron Tomlin
2022-02-09 14:28 ` Miroslav Benes
2022-01-30 21:32 ` [RFC PATCH v4 08/13] module: Move kmemleak support to a separate file Aaron Tomlin
` (8 subsequent siblings)
15 siblings, 1 reply; 39+ messages in thread
From: Aaron Tomlin @ 2022-01-30 21:32 UTC (permalink / raw)
To: mcgrof
Cc: cl, pmladek, mbenes, akpm, jeyu, linux-kernel, linux-modules,
live-patching, atomlin, ghalat, allen.lkml, void, joe
No functional change.
This patch migrates additional module signature check
code from core module code into kernel/module/signing.c.
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
include/linux/module.h | 5 ++-
kernel/module/internal.h | 9 +++++
kernel/module/main.c | 87 ----------------------------------------
kernel/module/signing.c | 75 ++++++++++++++++++++++++++++++++++
4 files changed, 87 insertions(+), 89 deletions(-)
diff --git a/include/linux/module.h b/include/linux/module.h
index 520c0f4bb968..15ba2ebbca3e 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -720,8 +720,8 @@ static inline bool set_livepatch_module(struct module *mod)
return false;
}
-bool is_module_sig_enforced(void);
-void set_module_sig_enforced(void);
+extern bool is_module_sig_enforced(void);
+extern void set_module_sig_enforced(void);
#else /* !CONFIG_MODULES... */
@@ -911,6 +911,7 @@ static inline bool module_sig_ok(struct module *module)
{
return true;
}
+#define sig_enforce false
#endif /* CONFIG_MODULE_SIG */
int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index de28d6bb7b5b..2ec2a1d9dd9f 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -114,3 +114,12 @@ static struct module *mod_find(unsigned long addr)
return NULL;
}
#endif /* CONFIG_MODULES_TREE_LOOKUP */
+
+#ifdef CONFIG_MODULE_SIG
+extern int module_sig_check(struct load_info *info, int flags);
+#else /* !CONFIG_MODULE_SIG */
+static int module_sig_check(struct load_info *info, int flags)
+{
+ return 0;
+}
+#endif /* !CONFIG_MODULE_SIG */
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 1a0e659a27bc..90c7266087d7 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -22,7 +22,6 @@
#include <linux/vmalloc.h>
#include <linux/elf.h>
#include <linux/proc_fs.h>
-#include <linux/security.h>
#include <linux/seq_file.h>
#include <linux/syscalls.h>
#include <linux/fcntl.h>
@@ -123,28 +122,6 @@ static void module_assert_mutex_or_preempt(void)
#endif
}
-#ifdef CONFIG_MODULE_SIG
-static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
-module_param(sig_enforce, bool_enable_only, 0644);
-
-void set_module_sig_enforced(void)
-{
- sig_enforce = true;
-}
-#else
-#define sig_enforce false
-#endif
-
-/*
- * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
- * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
- */
-bool is_module_sig_enforced(void)
-{
- return sig_enforce;
-}
-EXPORT_SYMBOL(is_module_sig_enforced);
-
/* Block module loading/unloading? */
int modules_disabled = 0;
core_param(nomodule, modules_disabled, bint, 0);
@@ -2525,70 +2502,6 @@ static inline void kmemleak_load_module(const struct module *mod,
}
#endif
-#ifdef CONFIG_MODULE_SIG
-static int module_sig_check(struct load_info *info, int flags)
-{
- int err = -ENODATA;
- const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
- const char *reason;
- const void *mod = info->hdr;
- bool mangled_module = flags & (MODULE_INIT_IGNORE_MODVERSIONS |
- MODULE_INIT_IGNORE_VERMAGIC);
- /*
- * Do not allow mangled modules as a module with version information
- * removed is no longer the module that was signed.
- */
- if (!mangled_module &&
- info->len > markerlen &&
- memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
- /* We truncate the module to discard the signature */
- info->len -= markerlen;
- err = mod_verify_sig(mod, info);
- if (!err) {
- info->sig_ok = true;
- return 0;
- }
- }
-
- /*
- * We don't permit modules to be loaded into the trusted kernels
- * without a valid signature on them, but if we're not enforcing,
- * certain errors are non-fatal.
- */
- switch (err) {
- case -ENODATA:
- reason = "unsigned module";
- break;
- case -ENOPKG:
- reason = "module with unsupported crypto";
- break;
- case -ENOKEY:
- reason = "module with unavailable key";
- break;
-
- default:
- /*
- * All other errors are fatal, including lack of memory,
- * unparseable signatures, and signature check failures --
- * even if signatures aren't required.
- */
- return err;
- }
-
- if (is_module_sig_enforced()) {
- pr_notice("Loading of %s is rejected\n", reason);
- return -EKEYREJECTED;
- }
-
- return security_locked_down(LOCKDOWN_MODULE_SIGNATURE);
-}
-#else /* !CONFIG_MODULE_SIG */
-static int module_sig_check(struct load_info *info, int flags)
-{
- return 0;
-}
-#endif /* !CONFIG_MODULE_SIG */
-
static int validate_section_offset(struct load_info *info, Elf_Shdr *shdr)
{
#if defined(CONFIG_64BIT)
diff --git a/kernel/module/signing.c b/kernel/module/signing.c
index 8aeb6d2ee94b..ff41541e982a 100644
--- a/kernel/module/signing.c
+++ b/kernel/module/signing.c
@@ -11,9 +11,28 @@
#include <linux/module_signature.h>
#include <linux/string.h>
#include <linux/verification.h>
+#include <linux/security.h>
#include <crypto/public_key.h>
#include "internal.h"
+static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
+module_param(sig_enforce, bool_enable_only, 0644);
+
+/*
+ * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
+ * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
+ */
+bool is_module_sig_enforced(void)
+{
+ return sig_enforce;
+}
+EXPORT_SYMBOL(is_module_sig_enforced);
+
+void set_module_sig_enforced(void)
+{
+ sig_enforce = true;
+}
+
/*
* Verify the signature on a module.
*/
@@ -43,3 +62,59 @@ int mod_verify_sig(const void *mod, struct load_info *info)
VERIFYING_MODULE_SIGNATURE,
NULL, NULL);
}
+
+int module_sig_check(struct load_info *info, int flags)
+{
+ int err = -ENODATA;
+ const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
+ const char *reason;
+ const void *mod = info->hdr;
+
+ /*
+ * Require flags == 0, as a module with version information
+ * removed is no longer the module that was signed
+ */
+ if (flags == 0 &&
+ info->len > markerlen &&
+ memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
+ /* We truncate the module to discard the signature */
+ info->len -= markerlen;
+ err = mod_verify_sig(mod, info);
+ if (!err) {
+ info->sig_ok = true;
+ return 0;
+ }
+ }
+
+ /*
+ * We don't permit modules to be loaded into the trusted kernels
+ * without a valid signature on them, but if we're not enforcing,
+ * certain errors are non-fatal.
+ */
+ switch (err) {
+ case -ENODATA:
+ reason = "unsigned module";
+ break;
+ case -ENOPKG:
+ reason = "module with unsupported crypto";
+ break;
+ case -ENOKEY:
+ reason = "module with unavailable key";
+ break;
+
+ default:
+ /*
+ * All other errors are fatal, including lack of memory,
+ * unparseable signatures, and signature check failures --
+ * even if signatures aren't required.
+ */
+ return err;
+ }
+
+ if (is_module_sig_enforced()) {
+ pr_notice("Loading of %s is rejected\n", reason);
+ return -EKEYREJECTED;
+ }
+
+ return security_locked_down(LOCKDOWN_MODULE_SIGNATURE);
+}
--
2.34.1
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [RFC PATCH v4 08/13] module: Move kmemleak support to a separate file
2022-01-30 21:32 [RFC PATCH v4 00/13] module: core code clean up Aaron Tomlin
` (6 preceding siblings ...)
2022-01-30 21:32 ` [RFC PATCH v4 07/13] module: Move extra signature support out of core code Aaron Tomlin
@ 2022-01-30 21:32 ` Aaron Tomlin
2022-01-30 21:32 ` [RFC PATCH v4 09/13] module: Move kallsyms support into " Aaron Tomlin
` (7 subsequent siblings)
15 siblings, 0 replies; 39+ messages in thread
From: Aaron Tomlin @ 2022-01-30 21:32 UTC (permalink / raw)
To: mcgrof
Cc: cl, pmladek, mbenes, akpm, jeyu, linux-kernel, linux-modules,
live-patching, atomlin, ghalat, allen.lkml, void, joe
No functional change.
This patch migrates kmemleak code out of core module
code into kernel/module/debug_kmemleak.c
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
kernel/module/Makefile | 1 +
kernel/module/debug_kmemleak.c | 30 ++++++++++++++++++++++++++++++
kernel/module/internal.h | 8 ++++++++
kernel/module/main.c | 27 ---------------------------
4 files changed, 39 insertions(+), 27 deletions(-)
create mode 100644 kernel/module/debug_kmemleak.c
diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index d1dada641ad6..10efb144551b 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -12,4 +12,5 @@ obj-$(CONFIG_LIVEPATCH) += livepatch.o
obj-$(CONFIG_MODULES_TREE_LOOKUP) += tree_lookup.o
obj-$(CONFIG_ARCH_HAS_STRICT_MODULE_RWX) += arch_strict_rwx.o
obj-$(CONFIG_STRICT_MODULE_RWX) += strict_rwx.o
+obj-$(CONFIG_DEBUG_KMEMLEAK) += debug_kmemleak.o
endif
diff --git a/kernel/module/debug_kmemleak.c b/kernel/module/debug_kmemleak.c
new file mode 100644
index 000000000000..e896c2268011
--- /dev/null
+++ b/kernel/module/debug_kmemleak.c
@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Module kmemleak support
+ *
+ * Copyright (C) 2009 Catalin Marinas
+ */
+
+#include <linux/module.h>
+#include <linux/kmemleak.h>
+#include "internal.h"
+
+void kmemleak_load_module(const struct module *mod,
+ const struct load_info *info)
+{
+ unsigned int i;
+
+ /* only scan the sections containing data */
+ kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
+
+ for (i = 1; i < info->hdr->e_shnum; i++) {
+ /* Scan all writable sections that's not executable */
+ if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
+ !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
+ (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
+ continue;
+
+ kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
+ info->sechdrs[i].sh_size, GFP_KERNEL);
+ }
+}
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index 2ec2a1d9dd9f..4c2f64a75401 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -6,6 +6,7 @@
*/
#include <linux/elf.h>
+#include <linux/compiler.h>
#include <asm/module.h>
#include <linux/mutex.h>
@@ -123,3 +124,10 @@ static int module_sig_check(struct load_info *info, int flags)
return 0;
}
#endif /* !CONFIG_MODULE_SIG */
+
+#ifdef CONFIG_DEBUG_KMEMLEAK
+extern void kmemleak_load_module(const struct module *mod, const struct load_info *info);
+#else /* !CONFIG_DEBUG_KMEMLEAK */
+static inline void __maybe_unused kmemleak_load_module(const struct module *mod,
+ const struct load_info *info) { }
+#endif /* CONFIG_DEBUG_KMEMLEAK */
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 90c7266087d7..80790d39a6b3 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -2475,33 +2475,6 @@ bool __weak module_exit_section(const char *name)
return strstarts(name, ".exit");
}
-#ifdef CONFIG_DEBUG_KMEMLEAK
-static void kmemleak_load_module(const struct module *mod,
- const struct load_info *info)
-{
- unsigned int i;
-
- /* only scan the sections containing data */
- kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
-
- for (i = 1; i < info->hdr->e_shnum; i++) {
- /* Scan all writable sections that's not executable */
- if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
- !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
- (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
- continue;
-
- kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
- info->sechdrs[i].sh_size, GFP_KERNEL);
- }
-}
-#else
-static inline void kmemleak_load_module(const struct module *mod,
- const struct load_info *info)
-{
-}
-#endif
-
static int validate_section_offset(struct load_info *info, Elf_Shdr *shdr)
{
#if defined(CONFIG_64BIT)
--
2.34.1
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [RFC PATCH v4 09/13] module: Move kallsyms support into a separate file
2022-01-30 21:32 [RFC PATCH v4 00/13] module: core code clean up Aaron Tomlin
` (7 preceding siblings ...)
2022-01-30 21:32 ` [RFC PATCH v4 08/13] module: Move kmemleak support to a separate file Aaron Tomlin
@ 2022-01-30 21:32 ` Aaron Tomlin
2022-01-30 21:32 ` [RFC PATCH v4 10/13] module: Move procfs " Aaron Tomlin
` (6 subsequent siblings)
15 siblings, 0 replies; 39+ messages in thread
From: Aaron Tomlin @ 2022-01-30 21:32 UTC (permalink / raw)
To: mcgrof
Cc: cl, pmladek, mbenes, akpm, jeyu, linux-kernel, linux-modules,
live-patching, atomlin, ghalat, allen.lkml, void, joe
No functional change.
This patch migrates kallsyms code out of core module
code kernel/module/kallsyms.c
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
kernel/module/Makefile | 1 +
kernel/module/internal.h | 27 ++
kernel/module/kallsyms.c | 502 +++++++++++++++++++++++++++++++++++++
kernel/module/main.c | 516 +--------------------------------------
4 files changed, 534 insertions(+), 512 deletions(-)
create mode 100644 kernel/module/kallsyms.c
diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index 10efb144551b..906f83e1931b 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -13,4 +13,5 @@ obj-$(CONFIG_MODULES_TREE_LOOKUP) += tree_lookup.o
obj-$(CONFIG_ARCH_HAS_STRICT_MODULE_RWX) += arch_strict_rwx.o
obj-$(CONFIG_STRICT_MODULE_RWX) += strict_rwx.o
obj-$(CONFIG_DEBUG_KMEMLEAK) += debug_kmemleak.o
+obj-$(CONFIG_KALLSYMS) += kallsyms.o
endif
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index 4c2f64a75401..866fce7c1a33 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -57,6 +57,11 @@ struct load_info {
};
extern int mod_verify_sig(const void *mod, struct load_info *info);
+extern struct module *find_module_all(const char *name, size_t len, bool even_unformed);
+extern unsigned long kernel_symbol_value(const struct kernel_symbol *sym);
+extern int cmp_name(const void *name, const void *sym);
+extern long get_offset(struct module *mod, unsigned int *size, Elf_Shdr *sechdr,
+ unsigned int section);
#ifdef CONFIG_LIVEPATCH
extern int copy_module_elf(struct module *mod, struct load_info *info);
@@ -131,3 +136,25 @@ extern void kmemleak_load_module(const struct module *mod, const struct load_inf
static inline void __maybe_unused kmemleak_load_module(const struct module *mod,
const struct load_info *info) { }
#endif /* CONFIG_DEBUG_KMEMLEAK */
+
+#ifdef CONFIG_KALLSYMS
+#ifdef CONFIG_STACKTRACE_BUILD_ID
+extern void init_build_id(struct module *mod, const struct load_info *info);
+#else /* !CONFIG_STACKTRACE_BUILD_ID */
+static inline void init_build_id(struct module *mod, const struct load_info *info) { }
+
+#endif
+extern void layout_symtab(struct module *mod, struct load_info *info);
+extern void add_kallsyms(struct module *mod, const struct load_info *info);
+extern bool sect_empty(const Elf_Shdr *sect);
+extern const char *find_kallsyms_symbol(struct module *mod, unsigned long addr,
+ unsigned long *size, unsigned long *offset);
+#else /* !CONFIG_KALLSYMS */
+static inline void layout_symtab(struct module *mod, struct load_info *info) { }
+static inline void add_kallsyms(struct module *mod, const struct load_info *info) { }
+static inline char *find_kallsyms_symbol(struct module *mod, unsigned long addr,
+ unsigned long *size, unsigned long *offset)
+{
+ return NULL;
+}
+#endif /* CONFIG_KALLSYMS */
diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c
new file mode 100644
index 000000000000..ed28f6310701
--- /dev/null
+++ b/kernel/module/kallsyms.c
@@ -0,0 +1,502 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Module kallsyms support
+ *
+ * Copyright (C) 2010 Rusty Russell
+ */
+
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+#include <linux/buildid.h>
+#include <linux/bsearch.h>
+#include "internal.h"
+
+/* Lookup exported symbol in given range of kernel_symbols */
+static const struct kernel_symbol *lookup_exported_symbol(const char *name,
+ const struct kernel_symbol *start,
+ const struct kernel_symbol *stop)
+{
+ return bsearch(name, start, stop - start,
+ sizeof(struct kernel_symbol), cmp_name);
+}
+
+static int is_exported(const char *name, unsigned long value,
+ const struct module *mod)
+{
+ const struct kernel_symbol *ks;
+
+ if (!mod)
+ ks = lookup_exported_symbol(name, __start___ksymtab, __stop___ksymtab);
+ else
+ ks = lookup_exported_symbol(name, mod->syms, mod->syms + mod->num_syms);
+
+ return ks != NULL && kernel_symbol_value(ks) == value;
+}
+
+/* As per nm */
+static char elf_type(const Elf_Sym *sym, const struct load_info *info)
+{
+ const Elf_Shdr *sechdrs = info->sechdrs;
+
+ if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
+ if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
+ return 'v';
+ else
+ return 'w';
+ }
+ if (sym->st_shndx == SHN_UNDEF)
+ return 'U';
+ if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
+ return 'a';
+ if (sym->st_shndx >= SHN_LORESERVE)
+ return '?';
+ if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
+ return 't';
+ if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
+ && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
+ if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
+ return 'r';
+ else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
+ return 'g';
+ else
+ return 'd';
+ }
+ if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
+ if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
+ return 's';
+ else
+ return 'b';
+ }
+ if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
+ ".debug")) {
+ return 'n';
+ }
+ return '?';
+}
+
+static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
+ unsigned int shnum, unsigned int pcpundx)
+{
+ const Elf_Shdr *sec;
+
+ if (src->st_shndx == SHN_UNDEF
+ || src->st_shndx >= shnum
+ || !src->st_name)
+ return false;
+
+#ifdef CONFIG_KALLSYMS_ALL
+ if (src->st_shndx == pcpundx)
+ return true;
+#endif
+
+ sec = sechdrs + src->st_shndx;
+ if (!(sec->sh_flags & SHF_ALLOC)
+#ifndef CONFIG_KALLSYMS_ALL
+ || !(sec->sh_flags & SHF_EXECINSTR)
+#endif
+ || (sec->sh_entsize & INIT_OFFSET_MASK))
+ return false;
+
+ return true;
+}
+
+/*
+ * We only allocate and copy the strings needed by the parts of symtab
+ * we keep. This is simple, but has the effect of making multiple
+ * copies of duplicates. We could be more sophisticated, see
+ * linux-kernel thread starting with
+ * <73defb5e4bca04a6431392cc341112b1@localhost>.
+ */
+void layout_symtab(struct module *mod, struct load_info *info)
+{
+ Elf_Shdr *symsect = info->sechdrs + info->index.sym;
+ Elf_Shdr *strsect = info->sechdrs + info->index.str;
+ const Elf_Sym *src;
+ unsigned int i, nsrc, ndst, strtab_size = 0;
+
+ /* Put symbol section at end of init part of module. */
+ symsect->sh_flags |= SHF_ALLOC;
+ symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
+ info->index.sym) | INIT_OFFSET_MASK;
+ pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
+
+ src = (void *)info->hdr + symsect->sh_offset;
+ nsrc = symsect->sh_size / sizeof(*src);
+
+ /* Compute total space required for the core symbols' strtab. */
+ for (ndst = i = 0; i < nsrc; i++) {
+ if (i == 0 || is_livepatch_module(mod) ||
+ is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
+ info->index.pcpu)) {
+ strtab_size += strlen(&info->strtab[src[i].st_name])+1;
+ ndst++;
+ }
+ }
+
+ /* Append room for core symbols at end of core part. */
+ info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
+ info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
+ mod->core_layout.size += strtab_size;
+ info->core_typeoffs = mod->core_layout.size;
+ mod->core_layout.size += ndst * sizeof(char);
+ mod->core_layout.size = debug_align(mod->core_layout.size);
+
+ /* Put string table section at end of init part of module. */
+ strsect->sh_flags |= SHF_ALLOC;
+ strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
+ info->index.str) | INIT_OFFSET_MASK;
+ pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
+
+ /* We'll tack temporary mod_kallsyms on the end. */
+ mod->init_layout.size = ALIGN(mod->init_layout.size,
+ __alignof__(struct mod_kallsyms));
+ info->mod_kallsyms_init_off = mod->init_layout.size;
+ mod->init_layout.size += sizeof(struct mod_kallsyms);
+ info->init_typeoffs = mod->init_layout.size;
+ mod->init_layout.size += nsrc * sizeof(char);
+ mod->init_layout.size = debug_align(mod->init_layout.size);
+}
+
+/*
+ * We use the full symtab and strtab which layout_symtab arranged to
+ * be appended to the init section. Later we switch to the cut-down
+ * core-only ones.
+ */
+void add_kallsyms(struct module *mod, const struct load_info *info)
+{
+ unsigned int i, ndst;
+ const Elf_Sym *src;
+ Elf_Sym *dst;
+ char *s;
+ Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
+
+ /* Set up to point into init section. */
+ mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
+
+ mod->kallsyms->symtab = (void *)symsec->sh_addr;
+ mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
+ /* Make sure we get permanent strtab: don't use info->strtab. */
+ mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
+ mod->kallsyms->typetab = mod->init_layout.base + info->init_typeoffs;
+
+ /*
+ * Now populate the cut down core kallsyms for after init
+ * and set types up while we still have access to sections.
+ */
+ mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
+ mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
+ mod->core_kallsyms.typetab = mod->core_layout.base + info->core_typeoffs;
+ src = mod->kallsyms->symtab;
+ for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
+ mod->kallsyms->typetab[i] = elf_type(src + i, info);
+ if (i == 0 || is_livepatch_module(mod) ||
+ is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
+ info->index.pcpu)) {
+ mod->core_kallsyms.typetab[ndst] =
+ mod->kallsyms->typetab[i];
+ dst[ndst] = src[i];
+ dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
+ s += strscpy(s, &mod->kallsyms->strtab[src[i].st_name],
+ KSYM_NAME_LEN) + 1;
+ }
+ }
+ mod->core_kallsyms.num_symtab = ndst;
+}
+
+inline bool sect_empty(const Elf_Shdr *sect)
+{
+ return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
+}
+
+#ifdef CONFIG_STACKTRACE_BUILD_ID
+void init_build_id(struct module *mod, const struct load_info *info)
+{
+ const Elf_Shdr *sechdr;
+ unsigned int i;
+
+ for (i = 0; i < info->hdr->e_shnum; i++) {
+ sechdr = &info->sechdrs[i];
+ if (!sect_empty(sechdr) && sechdr->sh_type == SHT_NOTE &&
+ !build_id_parse_buf((void *)sechdr->sh_addr, mod->build_id,
+ sechdr->sh_size))
+ break;
+ }
+}
+#endif
+
+/*
+ * This ignores the intensely annoying "mapping symbols" found
+ * in ARM ELF files: $a, $t and $d.
+ */
+static inline int is_arm_mapping_symbol(const char *str)
+{
+ if (str[0] == '.' && str[1] == 'L')
+ return true;
+ return str[0] == '$' && strchr("axtd", str[1])
+ && (str[2] == '\0' || str[2] == '.');
+}
+
+static const char *kallsyms_symbol_name(struct mod_kallsyms *kallsyms, unsigned int symnum)
+{
+ return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
+}
+
+/*
+ * Given a module and address, find the corresponding symbol and return its name
+ * while providing its size and offset if needed.
+ */
+const char *find_kallsyms_symbol(struct module *mod,
+ unsigned long addr,
+ unsigned long *size,
+ unsigned long *offset)
+{
+ unsigned int i, best = 0;
+ unsigned long nextval, bestval;
+ struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
+
+ /* At worse, next value is at end of module */
+ if (within_module_init(addr, mod))
+ nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
+ else
+ nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
+
+ bestval = kallsyms_symbol_value(&kallsyms->symtab[best]);
+
+ /*
+ * Scan for closest preceding symbol, and next symbol. (ELF
+ * starts real symbols at 1).
+ */
+ for (i = 1; i < kallsyms->num_symtab; i++) {
+ const Elf_Sym *sym = &kallsyms->symtab[i];
+ unsigned long thisval = kallsyms_symbol_value(sym);
+
+ if (sym->st_shndx == SHN_UNDEF)
+ continue;
+
+ /*
+ * We ignore unnamed symbols: they're uninformative
+ * and inserted at a whim.
+ */
+ if (*kallsyms_symbol_name(kallsyms, i) == '\0'
+ || is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms, i)))
+ continue;
+
+ if (thisval <= addr && thisval > bestval) {
+ best = i;
+ bestval = thisval;
+ }
+ if (thisval > addr && thisval < nextval)
+ nextval = thisval;
+ }
+
+ if (!best)
+ return NULL;
+
+ if (size)
+ *size = nextval - bestval;
+ if (offset)
+ *offset = addr - bestval;
+
+ return kallsyms_symbol_name(kallsyms, best);
+}
+
+void * __weak dereference_module_function_descriptor(struct module *mod,
+ void *ptr)
+{
+ return ptr;
+}
+
+/*
+ * For kallsyms to ask for address resolution. NULL means not found. Careful
+ * not to lock to avoid deadlock on oopses, simply disable preemption.
+ */
+const char *module_address_lookup(unsigned long addr,
+ unsigned long *size,
+ unsigned long *offset,
+ char **modname,
+ const unsigned char **modbuildid,
+ char *namebuf)
+{
+ const char *ret = NULL;
+ struct module *mod;
+
+ preempt_disable();
+ mod = __module_address(addr);
+ if (mod) {
+ if (modname)
+ *modname = mod->name;
+ if (modbuildid) {
+#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
+ *modbuildid = mod->build_id;
+#else
+ *modbuildid = NULL;
+#endif
+ }
+
+ ret = find_kallsyms_symbol(mod, addr, size, offset);
+ }
+ /* Make a copy in here where it's safe */
+ if (ret) {
+ strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
+ ret = namebuf;
+ }
+ preempt_enable();
+
+ return ret;
+}
+
+int lookup_module_symbol_name(unsigned long addr, char *symname)
+{
+ struct module *mod;
+
+ preempt_disable();
+ list_for_each_entry_rcu(mod, &modules, list) {
+ if (mod->state == MODULE_STATE_UNFORMED)
+ continue;
+ if (within_module(addr, mod)) {
+ const char *sym;
+
+ sym = find_kallsyms_symbol(mod, addr, NULL, NULL);
+ if (!sym)
+ goto out;
+
+ strscpy(symname, sym, KSYM_NAME_LEN);
+ preempt_enable();
+ return 0;
+ }
+ }
+out:
+ preempt_enable();
+ return -ERANGE;
+}
+
+int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
+ unsigned long *offset, char *modname, char *name)
+{
+ struct module *mod;
+
+ preempt_disable();
+ list_for_each_entry_rcu(mod, &modules, list) {
+ if (mod->state == MODULE_STATE_UNFORMED)
+ continue;
+ if (within_module(addr, mod)) {
+ const char *sym;
+
+ sym = find_kallsyms_symbol(mod, addr, size, offset);
+ if (!sym)
+ goto out;
+ if (modname)
+ strscpy(modname, mod->name, MODULE_NAME_LEN);
+ if (name)
+ strscpy(name, sym, KSYM_NAME_LEN);
+ preempt_enable();
+ return 0;
+ }
+ }
+out:
+ preempt_enable();
+ return -ERANGE;
+}
+
+int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
+ char *name, char *module_name, int *exported)
+{
+ struct module *mod;
+
+ preempt_disable();
+ list_for_each_entry_rcu(mod, &modules, list) {
+ struct mod_kallsyms *kallsyms;
+
+ if (mod->state == MODULE_STATE_UNFORMED)
+ continue;
+ kallsyms = rcu_dereference_sched(mod->kallsyms);
+ if (symnum < kallsyms->num_symtab) {
+ const Elf_Sym *sym = &kallsyms->symtab[symnum];
+
+ *value = kallsyms_symbol_value(sym);
+ *type = kallsyms->typetab[symnum];
+ strscpy(name, kallsyms_symbol_name(kallsyms, symnum), KSYM_NAME_LEN);
+ strscpy(module_name, mod->name, MODULE_NAME_LEN);
+ *exported = is_exported(name, *value, mod);
+ preempt_enable();
+ return 0;
+ }
+ symnum -= kallsyms->num_symtab;
+ }
+ preempt_enable();
+ return -ERANGE;
+}
+
+/* Given a module and name of symbol, find and return the symbol's value */
+static unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name)
+{
+ unsigned int i;
+ struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
+
+ for (i = 0; i < kallsyms->num_symtab; i++) {
+ const Elf_Sym *sym = &kallsyms->symtab[i];
+
+ if (strcmp(name, kallsyms_symbol_name(kallsyms, i)) == 0 &&
+ sym->st_shndx != SHN_UNDEF)
+ return kallsyms_symbol_value(sym);
+ }
+ return 0;
+}
+
+/* Look for this name: can be of form module:name. */
+unsigned long module_kallsyms_lookup_name(const char *name)
+{
+ struct module *mod;
+ char *colon;
+ unsigned long ret = 0;
+
+ /* Don't lock: we're in enough trouble already. */
+ preempt_disable();
+ if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
+ if ((mod = find_module_all(name, colon - name, false)) != NULL)
+ ret = find_kallsyms_symbol_value(mod, colon+1);
+ } else {
+ list_for_each_entry_rcu(mod, &modules, list) {
+ if (mod->state == MODULE_STATE_UNFORMED)
+ continue;
+ if ((ret = find_kallsyms_symbol_value(mod, name)) != 0)
+ break;
+ }
+ }
+ preempt_enable();
+ return ret;
+}
+
+#ifdef CONFIG_LIVEPATCH
+int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
+ struct module *, unsigned long),
+ void *data)
+{
+ struct module *mod;
+ unsigned int i;
+ int ret = 0;
+
+ mutex_lock(&module_mutex);
+ list_for_each_entry(mod, &modules, list) {
+ /* We hold module_mutex: no need for rcu_dereference_sched */
+ struct mod_kallsyms *kallsyms = mod->kallsyms;
+
+ if (mod->state == MODULE_STATE_UNFORMED)
+ continue;
+ for (i = 0; i < kallsyms->num_symtab; i++) {
+ const Elf_Sym *sym = &kallsyms->symtab[i];
+
+ if (sym->st_shndx == SHN_UNDEF)
+ continue;
+
+ ret = fn(data, kallsyms_symbol_name(kallsyms, i),
+ mod, kallsyms_symbol_value(sym));
+ if (ret != 0)
+ goto out;
+ }
+ }
+out:
+ mutex_unlock(&module_mutex);
+ return ret;
+}
+#endif /* CONFIG_LIVEPATCH */
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 80790d39a6b3..363a54298f7e 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -284,7 +284,7 @@ static bool check_exported_symbol(const struct symsearch *syms,
return true;
}
-static unsigned long kernel_symbol_value(const struct kernel_symbol *sym)
+unsigned long kernel_symbol_value(const struct kernel_symbol *sym)
{
#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
return (unsigned long)offset_to_ptr(&sym->value_offset);
@@ -313,7 +313,7 @@ static const char *kernel_symbol_namespace(const struct kernel_symbol *sym)
#endif
}
-static int cmp_name(const void *name, const void *sym)
+int cmp_name(const void *name, const void *sym)
{
return strcmp(name, kernel_symbol_name(sym));
}
@@ -383,7 +383,7 @@ static bool find_symbol(struct find_symbol_arg *fsa)
* Search for module by name: must hold module_mutex (or preempt disabled
* for read-only access).
*/
-static struct module *find_module_all(const char *name, size_t len,
+struct module *find_module_all(const char *name, size_t len,
bool even_unformed)
{
struct module *mod;
@@ -1290,13 +1290,6 @@ resolve_symbol_wait(struct module *mod,
return ksym;
}
-#ifdef CONFIG_KALLSYMS
-static inline bool sect_empty(const Elf_Shdr *sect)
-{
- return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
-}
-#endif
-
/*
* /sys/module/foo/sections stuff
* J. Corbet <corbet@lwn.net>
@@ -2021,7 +2014,7 @@ unsigned int __weak arch_mod_section_prepend(struct module *mod,
}
/* Update size with this section: return offset. */
-static long get_offset(struct module *mod, unsigned int *size,
+long get_offset(struct module *mod, unsigned int *size,
Elf_Shdr *sechdr, unsigned int section)
{
long ret;
@@ -2223,228 +2216,6 @@ static void free_modinfo(struct module *mod)
}
}
-#ifdef CONFIG_KALLSYMS
-
-/* Lookup exported symbol in given range of kernel_symbols */
-static const struct kernel_symbol *lookup_exported_symbol(const char *name,
- const struct kernel_symbol *start,
- const struct kernel_symbol *stop)
-{
- return bsearch(name, start, stop - start,
- sizeof(struct kernel_symbol), cmp_name);
-}
-
-static int is_exported(const char *name, unsigned long value,
- const struct module *mod)
-{
- const struct kernel_symbol *ks;
- if (!mod)
- ks = lookup_exported_symbol(name, __start___ksymtab, __stop___ksymtab);
- else
- ks = lookup_exported_symbol(name, mod->syms, mod->syms + mod->num_syms);
-
- return ks != NULL && kernel_symbol_value(ks) == value;
-}
-
-/* As per nm */
-static char elf_type(const Elf_Sym *sym, const struct load_info *info)
-{
- const Elf_Shdr *sechdrs = info->sechdrs;
-
- if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
- if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
- return 'v';
- else
- return 'w';
- }
- if (sym->st_shndx == SHN_UNDEF)
- return 'U';
- if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
- return 'a';
- if (sym->st_shndx >= SHN_LORESERVE)
- return '?';
- if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
- return 't';
- if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
- && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
- if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
- return 'r';
- else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
- return 'g';
- else
- return 'd';
- }
- if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
- if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
- return 's';
- else
- return 'b';
- }
- if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
- ".debug")) {
- return 'n';
- }
- return '?';
-}
-
-static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
- unsigned int shnum, unsigned int pcpundx)
-{
- const Elf_Shdr *sec;
-
- if (src->st_shndx == SHN_UNDEF
- || src->st_shndx >= shnum
- || !src->st_name)
- return false;
-
-#ifdef CONFIG_KALLSYMS_ALL
- if (src->st_shndx == pcpundx)
- return true;
-#endif
-
- sec = sechdrs + src->st_shndx;
- if (!(sec->sh_flags & SHF_ALLOC)
-#ifndef CONFIG_KALLSYMS_ALL
- || !(sec->sh_flags & SHF_EXECINSTR)
-#endif
- || (sec->sh_entsize & INIT_OFFSET_MASK))
- return false;
-
- return true;
-}
-
-/*
- * We only allocate and copy the strings needed by the parts of symtab
- * we keep. This is simple, but has the effect of making multiple
- * copies of duplicates. We could be more sophisticated, see
- * linux-kernel thread starting with
- * <73defb5e4bca04a6431392cc341112b1@localhost>.
- */
-static void layout_symtab(struct module *mod, struct load_info *info)
-{
- Elf_Shdr *symsect = info->sechdrs + info->index.sym;
- Elf_Shdr *strsect = info->sechdrs + info->index.str;
- const Elf_Sym *src;
- unsigned int i, nsrc, ndst, strtab_size = 0;
-
- /* Put symbol section at end of init part of module. */
- symsect->sh_flags |= SHF_ALLOC;
- symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
- info->index.sym) | INIT_OFFSET_MASK;
- pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
-
- src = (void *)info->hdr + symsect->sh_offset;
- nsrc = symsect->sh_size / sizeof(*src);
-
- /* Compute total space required for the core symbols' strtab. */
- for (ndst = i = 0; i < nsrc; i++) {
- if (i == 0 || is_livepatch_module(mod) ||
- is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
- info->index.pcpu)) {
- strtab_size += strlen(&info->strtab[src[i].st_name])+1;
- ndst++;
- }
- }
-
- /* Append room for core symbols at end of core part. */
- info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
- info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
- mod->core_layout.size += strtab_size;
- info->core_typeoffs = mod->core_layout.size;
- mod->core_layout.size += ndst * sizeof(char);
- mod->core_layout.size = debug_align(mod->core_layout.size);
-
- /* Put string table section at end of init part of module. */
- strsect->sh_flags |= SHF_ALLOC;
- strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
- info->index.str) | INIT_OFFSET_MASK;
- pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
-
- /* We'll tack temporary mod_kallsyms on the end. */
- mod->init_layout.size = ALIGN(mod->init_layout.size,
- __alignof__(struct mod_kallsyms));
- info->mod_kallsyms_init_off = mod->init_layout.size;
- mod->init_layout.size += sizeof(struct mod_kallsyms);
- info->init_typeoffs = mod->init_layout.size;
- mod->init_layout.size += nsrc * sizeof(char);
- mod->init_layout.size = debug_align(mod->init_layout.size);
-}
-
-/*
- * We use the full symtab and strtab which layout_symtab arranged to
- * be appended to the init section. Later we switch to the cut-down
- * core-only ones.
- */
-static void add_kallsyms(struct module *mod, const struct load_info *info)
-{
- unsigned int i, ndst;
- const Elf_Sym *src;
- Elf_Sym *dst;
- char *s;
- Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
-
- /* Set up to point into init section. */
- mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
-
- mod->kallsyms->symtab = (void *)symsec->sh_addr;
- mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
- /* Make sure we get permanent strtab: don't use info->strtab. */
- mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
- mod->kallsyms->typetab = mod->init_layout.base + info->init_typeoffs;
-
- /*
- * Now populate the cut down core kallsyms for after init
- * and set types up while we still have access to sections.
- */
- mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
- mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
- mod->core_kallsyms.typetab = mod->core_layout.base + info->core_typeoffs;
- src = mod->kallsyms->symtab;
- for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
- mod->kallsyms->typetab[i] = elf_type(src + i, info);
- if (i == 0 || is_livepatch_module(mod) ||
- is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
- info->index.pcpu)) {
- mod->core_kallsyms.typetab[ndst] =
- mod->kallsyms->typetab[i];
- dst[ndst] = src[i];
- dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
- s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
- KSYM_NAME_LEN) + 1;
- }
- }
- mod->core_kallsyms.num_symtab = ndst;
-}
-#else
-static inline void layout_symtab(struct module *mod, struct load_info *info)
-{
-}
-
-static void add_kallsyms(struct module *mod, const struct load_info *info)
-{
-}
-#endif /* CONFIG_KALLSYMS */
-
-#if IS_ENABLED(CONFIG_KALLSYMS) && IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
-static void init_build_id(struct module *mod, const struct load_info *info)
-{
- const Elf_Shdr *sechdr;
- unsigned int i;
-
- for (i = 0; i < info->hdr->e_shnum; i++) {
- sechdr = &info->sechdrs[i];
- if (!sect_empty(sechdr) && sechdr->sh_type == SHT_NOTE &&
- !build_id_parse_buf((void *)sechdr->sh_addr, mod->build_id,
- sechdr->sh_size))
- break;
- }
-}
-#else
-static void init_build_id(struct module *mod, const struct load_info *info)
-{
-}
-#endif
-
static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
{
if (!debug)
@@ -3770,285 +3541,6 @@ static inline int within(unsigned long addr, void *start, unsigned long size)
return ((void *)addr >= start && (void *)addr < start + size);
}
-#ifdef CONFIG_KALLSYMS
-/*
- * This ignores the intensely annoying "mapping symbols" found
- * in ARM ELF files: $a, $t and $d.
- */
-static inline int is_arm_mapping_symbol(const char *str)
-{
- if (str[0] == '.' && str[1] == 'L')
- return true;
- return str[0] == '$' && strchr("axtd", str[1])
- && (str[2] == '\0' || str[2] == '.');
-}
-
-static const char *kallsyms_symbol_name(struct mod_kallsyms *kallsyms, unsigned int symnum)
-{
- return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
-}
-
-/*
- * Given a module and address, find the corresponding symbol and return its name
- * while providing its size and offset if needed.
- */
-static const char *find_kallsyms_symbol(struct module *mod,
- unsigned long addr,
- unsigned long *size,
- unsigned long *offset)
-{
- unsigned int i, best = 0;
- unsigned long nextval, bestval;
- struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
-
- /* At worse, next value is at end of module */
- if (within_module_init(addr, mod))
- nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
- else
- nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
-
- bestval = kallsyms_symbol_value(&kallsyms->symtab[best]);
-
- /*
- * Scan for closest preceding symbol, and next symbol. (ELF
- * starts real symbols at 1).
- */
- for (i = 1; i < kallsyms->num_symtab; i++) {
- const Elf_Sym *sym = &kallsyms->symtab[i];
- unsigned long thisval = kallsyms_symbol_value(sym);
-
- if (sym->st_shndx == SHN_UNDEF)
- continue;
-
- /*
- * We ignore unnamed symbols: they're uninformative
- * and inserted at a whim.
- */
- if (*kallsyms_symbol_name(kallsyms, i) == '\0'
- || is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms, i)))
- continue;
-
- if (thisval <= addr && thisval > bestval) {
- best = i;
- bestval = thisval;
- }
- if (thisval > addr && thisval < nextval)
- nextval = thisval;
- }
-
- if (!best)
- return NULL;
-
- if (size)
- *size = nextval - bestval;
- if (offset)
- *offset = addr - bestval;
-
- return kallsyms_symbol_name(kallsyms, best);
-}
-
-void * __weak dereference_module_function_descriptor(struct module *mod,
- void *ptr)
-{
- return ptr;
-}
-
-/*
- * For kallsyms to ask for address resolution. NULL means not found. Careful
- * not to lock to avoid deadlock on oopses, simply disable preemption.
- */
-const char *module_address_lookup(unsigned long addr,
- unsigned long *size,
- unsigned long *offset,
- char **modname,
- const unsigned char **modbuildid,
- char *namebuf)
-{
- const char *ret = NULL;
- struct module *mod;
-
- preempt_disable();
- mod = __module_address(addr);
- if (mod) {
- if (modname)
- *modname = mod->name;
- if (modbuildid) {
-#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
- *modbuildid = mod->build_id;
-#else
- *modbuildid = NULL;
-#endif
- }
-
- ret = find_kallsyms_symbol(mod, addr, size, offset);
- }
- /* Make a copy in here where it's safe */
- if (ret) {
- strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
- ret = namebuf;
- }
- preempt_enable();
-
- return ret;
-}
-
-int lookup_module_symbol_name(unsigned long addr, char *symname)
-{
- struct module *mod;
-
- preempt_disable();
- list_for_each_entry_rcu(mod, &modules, list) {
- if (mod->state == MODULE_STATE_UNFORMED)
- continue;
- if (within_module(addr, mod)) {
- const char *sym;
-
- sym = find_kallsyms_symbol(mod, addr, NULL, NULL);
- if (!sym)
- goto out;
-
- strlcpy(symname, sym, KSYM_NAME_LEN);
- preempt_enable();
- return 0;
- }
- }
-out:
- preempt_enable();
- return -ERANGE;
-}
-
-int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
- unsigned long *offset, char *modname, char *name)
-{
- struct module *mod;
-
- preempt_disable();
- list_for_each_entry_rcu(mod, &modules, list) {
- if (mod->state == MODULE_STATE_UNFORMED)
- continue;
- if (within_module(addr, mod)) {
- const char *sym;
-
- sym = find_kallsyms_symbol(mod, addr, size, offset);
- if (!sym)
- goto out;
- if (modname)
- strlcpy(modname, mod->name, MODULE_NAME_LEN);
- if (name)
- strlcpy(name, sym, KSYM_NAME_LEN);
- preempt_enable();
- return 0;
- }
- }
-out:
- preempt_enable();
- return -ERANGE;
-}
-
-int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
- char *name, char *module_name, int *exported)
-{
- struct module *mod;
-
- preempt_disable();
- list_for_each_entry_rcu(mod, &modules, list) {
- struct mod_kallsyms *kallsyms;
-
- if (mod->state == MODULE_STATE_UNFORMED)
- continue;
- kallsyms = rcu_dereference_sched(mod->kallsyms);
- if (symnum < kallsyms->num_symtab) {
- const Elf_Sym *sym = &kallsyms->symtab[symnum];
-
- *value = kallsyms_symbol_value(sym);
- *type = kallsyms->typetab[symnum];
- strlcpy(name, kallsyms_symbol_name(kallsyms, symnum), KSYM_NAME_LEN);
- strlcpy(module_name, mod->name, MODULE_NAME_LEN);
- *exported = is_exported(name, *value, mod);
- preempt_enable();
- return 0;
- }
- symnum -= kallsyms->num_symtab;
- }
- preempt_enable();
- return -ERANGE;
-}
-
-/* Given a module and name of symbol, find and return the symbol's value */
-static unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name)
-{
- unsigned int i;
- struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
-
- for (i = 0; i < kallsyms->num_symtab; i++) {
- const Elf_Sym *sym = &kallsyms->symtab[i];
-
- if (strcmp(name, kallsyms_symbol_name(kallsyms, i)) == 0 &&
- sym->st_shndx != SHN_UNDEF)
- return kallsyms_symbol_value(sym);
- }
- return 0;
-}
-
-/* Look for this name: can be of form module:name. */
-unsigned long module_kallsyms_lookup_name(const char *name)
-{
- struct module *mod;
- char *colon;
- unsigned long ret = 0;
-
- /* Don't lock: we're in enough trouble already. */
- preempt_disable();
- if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
- if ((mod = find_module_all(name, colon - name, false)) != NULL)
- ret = find_kallsyms_symbol_value(mod, colon+1);
- } else {
- list_for_each_entry_rcu(mod, &modules, list) {
- if (mod->state == MODULE_STATE_UNFORMED)
- continue;
- if ((ret = find_kallsyms_symbol_value(mod, name)) != 0)
- break;
- }
- }
- preempt_enable();
- return ret;
-}
-
-#ifdef CONFIG_LIVEPATCH
-int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
- struct module *, unsigned long),
- void *data)
-{
- struct module *mod;
- unsigned int i;
- int ret = 0;
-
- mutex_lock(&module_mutex);
- list_for_each_entry(mod, &modules, list) {
- /* We hold module_mutex: no need for rcu_dereference_sched */
- struct mod_kallsyms *kallsyms = mod->kallsyms;
-
- if (mod->state == MODULE_STATE_UNFORMED)
- continue;
- for (i = 0; i < kallsyms->num_symtab; i++) {
- const Elf_Sym *sym = &kallsyms->symtab[i];
-
- if (sym->st_shndx == SHN_UNDEF)
- continue;
-
- ret = fn(data, kallsyms_symbol_name(kallsyms, i),
- mod, kallsyms_symbol_value(sym));
- if (ret != 0)
- goto out;
- }
- }
-out:
- mutex_unlock(&module_mutex);
- return ret;
-}
-#endif /* CONFIG_LIVEPATCH */
-#endif /* CONFIG_KALLSYMS */
-
static void cfi_init(struct module *mod)
{
#ifdef CONFIG_CFI_CLANG
--
2.34.1
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [RFC PATCH v4 10/13] module: Move procfs support into a separate file
2022-01-30 21:32 [RFC PATCH v4 00/13] module: core code clean up Aaron Tomlin
` (8 preceding siblings ...)
2022-01-30 21:32 ` [RFC PATCH v4 09/13] module: Move kallsyms support into " Aaron Tomlin
@ 2022-01-30 21:32 ` Aaron Tomlin
2022-01-30 21:32 ` [RFC PATCH v4 11/13] module: Move sysfs " Aaron Tomlin
` (5 subsequent siblings)
15 siblings, 0 replies; 39+ messages in thread
From: Aaron Tomlin @ 2022-01-30 21:32 UTC (permalink / raw)
To: mcgrof
Cc: cl, pmladek, mbenes, akpm, jeyu, linux-kernel, linux-modules,
live-patching, atomlin, ghalat, allen.lkml, void, joe
No functional change.
This patch migrates code that allows one to generate a
list of loaded/or linked modules via /proc when procfs
support is enabled into kernel/module/procfs.c.
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
kernel/module/Makefile | 1 +
kernel/module/internal.h | 1 +
kernel/module/main.c | 131 +-----------------------------------
kernel/module/procfs.c | 142 +++++++++++++++++++++++++++++++++++++++
4 files changed, 145 insertions(+), 130 deletions(-)
create mode 100644 kernel/module/procfs.c
diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index 906f83e1931b..812f11ad090e 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -14,4 +14,5 @@ obj-$(CONFIG_ARCH_HAS_STRICT_MODULE_RWX) += arch_strict_rwx.o
obj-$(CONFIG_STRICT_MODULE_RWX) += strict_rwx.o
obj-$(CONFIG_DEBUG_KMEMLEAK) += debug_kmemleak.o
obj-$(CONFIG_KALLSYMS) += kallsyms.o
+obj-$(CONFIG_PROC_FS) += procfs.o
endif
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index 866fce7c1a33..09484a9382bc 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -62,6 +62,7 @@ extern unsigned long kernel_symbol_value(const struct kernel_symbol *sym);
extern int cmp_name(const void *name, const void *sym);
extern long get_offset(struct module *mod, unsigned int *size, Elf_Shdr *sechdr,
unsigned int section);
+extern char *module_flags(struct module *mod, char *buf);
#ifdef CONFIG_LIVEPATCH
extern int copy_module_elf(struct module *mod, struct load_info *info);
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 363a54298f7e..1c20393ab76d 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -21,7 +21,6 @@
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/elf.h>
-#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/syscalls.h>
#include <linux/fcntl.h>
@@ -810,31 +809,6 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
return ret;
}
-static inline void print_unload_info(struct seq_file *m, struct module *mod)
-{
- struct module_use *use;
- int printed_something = 0;
-
- seq_printf(m, " %i ", module_refcount(mod));
-
- /*
- * Always include a trailing , so userspace can differentiate
- * between this and the old multi-field proc format.
- */
- list_for_each_entry(use, &mod->source_list, source_list) {
- printed_something = 1;
- seq_printf(m, "%s,", use->source->name);
- }
-
- if (mod->init != NULL && mod->exit == NULL) {
- printed_something = 1;
- seq_puts(m, "[permanent],");
- }
-
- if (!printed_something)
- seq_puts(m, "-");
-}
-
void __symbol_put(const char *symbol)
{
struct find_symbol_arg fsa = {
@@ -924,12 +898,6 @@ void module_put(struct module *module)
EXPORT_SYMBOL(module_put);
#else /* !CONFIG_MODULE_UNLOAD */
-static inline void print_unload_info(struct seq_file *m, struct module *mod)
-{
- /* We don't know the usage count, or what modules are using. */
- seq_puts(m, " - -");
-}
-
static inline void module_unload_free(struct module *mod)
{
}
@@ -3576,7 +3544,7 @@ static void cfi_cleanup(struct module *mod)
}
/* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
-static char *module_flags(struct module *mod, char *buf)
+char *module_flags(struct module *mod, char *buf)
{
int bx = 0;
@@ -3599,103 +3567,6 @@ static char *module_flags(struct module *mod, char *buf)
return buf;
}
-#ifdef CONFIG_PROC_FS
-/* Called by the /proc file system to return a list of modules. */
-static void *m_start(struct seq_file *m, loff_t *pos)
-{
- mutex_lock(&module_mutex);
- return seq_list_start(&modules, *pos);
-}
-
-static void *m_next(struct seq_file *m, void *p, loff_t *pos)
-{
- return seq_list_next(p, &modules, pos);
-}
-
-static void m_stop(struct seq_file *m, void *p)
-{
- mutex_unlock(&module_mutex);
-}
-
-static int m_show(struct seq_file *m, void *p)
-{
- struct module *mod = list_entry(p, struct module, list);
- char buf[MODULE_FLAGS_BUF_SIZE];
- void *value;
-
- /* We always ignore unformed modules. */
- if (mod->state == MODULE_STATE_UNFORMED)
- return 0;
-
- seq_printf(m, "%s %u",
- mod->name, mod->init_layout.size + mod->core_layout.size);
- print_unload_info(m, mod);
-
- /* Informative for users. */
- seq_printf(m, " %s",
- mod->state == MODULE_STATE_GOING ? "Unloading" :
- mod->state == MODULE_STATE_COMING ? "Loading" :
- "Live");
- /* Used by oprofile and other similar tools. */
- value = m->private ? NULL : mod->core_layout.base;
- seq_printf(m, " 0x%px", value);
-
- /* Taints info */
- if (mod->taints)
- seq_printf(m, " %s", module_flags(mod, buf));
-
- seq_puts(m, "\n");
- return 0;
-}
-
-/*
- * Format: modulename size refcount deps address
- *
- * Where refcount is a number or -, and deps is a comma-separated list
- * of depends or -.
- */
-static const struct seq_operations modules_op = {
- .start = m_start,
- .next = m_next,
- .stop = m_stop,
- .show = m_show
-};
-
-/*
- * This also sets the "private" pointer to non-NULL if the
- * kernel pointers should be hidden (so you can just test
- * "m->private" to see if you should keep the values private).
- *
- * We use the same logic as for /proc/kallsyms.
- */
-static int modules_open(struct inode *inode, struct file *file)
-{
- int err = seq_open(file, &modules_op);
-
- if (!err) {
- struct seq_file *m = file->private_data;
- m->private = kallsyms_show_value(file->f_cred) ? NULL : (void *)8ul;
- }
-
- return err;
-}
-
-static const struct proc_ops modules_proc_ops = {
- .proc_flags = PROC_ENTRY_PERMANENT,
- .proc_open = modules_open,
- .proc_read = seq_read,
- .proc_lseek = seq_lseek,
- .proc_release = seq_release,
-};
-
-static int __init proc_modules_init(void)
-{
- proc_create("modules", 0, NULL, &modules_proc_ops);
- return 0;
-}
-module_init(proc_modules_init);
-#endif
-
/* Given an address, look for it in the module exception tables. */
const struct exception_table_entry *search_module_extables(unsigned long addr)
{
diff --git a/kernel/module/procfs.c b/kernel/module/procfs.c
new file mode 100644
index 000000000000..d706a798b52e
--- /dev/null
+++ b/kernel/module/procfs.c
@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Module proc support
+ *
+ * Copyright (C) 2008 Alexey Dobriyan
+ */
+
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+#include <linux/mutex.h>
+#include <linux/seq_file.h>
+#include <linux/proc_fs.h>
+#include "internal.h"
+
+#ifdef CONFIG_MODULE_UNLOAD
+static inline void print_unload_info(struct seq_file *m, struct module *mod)
+{
+ struct module_use *use;
+ int printed_something = 0;
+
+ seq_printf(m, " %i ", module_refcount(mod));
+
+ /*
+ * Always include a trailing , so userspace can differentiate
+ * between this and the old multi-field proc format.
+ */
+ list_for_each_entry(use, &mod->source_list, source_list) {
+ printed_something = 1;
+ seq_printf(m, "%s,", use->source->name);
+ }
+
+ if (mod->init != NULL && mod->exit == NULL) {
+ printed_something = 1;
+ seq_puts(m, "[permanent],");
+ }
+
+ if (!printed_something)
+ seq_puts(m, "-");
+}
+#else /* !CONFIG_MODULE_UNLOAD */
+static inline void print_unload_info(struct seq_file *m, struct module *mod)
+{
+ /* We don't know the usage count, or what modules are using. */
+ seq_puts(m, " - -");
+}
+#endif /* CONFIG_MODULE_UNLOAD */
+
+/* Called by the /proc file system to return a list of modules. */
+static void *m_start(struct seq_file *m, loff_t *pos)
+{
+ mutex_lock(&module_mutex);
+ return seq_list_start(&modules, *pos);
+}
+
+static void *m_next(struct seq_file *m, void *p, loff_t *pos)
+{
+ return seq_list_next(p, &modules, pos);
+}
+
+static void m_stop(struct seq_file *m, void *p)
+{
+ mutex_unlock(&module_mutex);
+}
+
+static int m_show(struct seq_file *m, void *p)
+{
+ struct module *mod = list_entry(p, struct module, list);
+ char buf[MODULE_FLAGS_BUF_SIZE];
+ void *value;
+
+ /* We always ignore unformed modules. */
+ if (mod->state == MODULE_STATE_UNFORMED)
+ return 0;
+
+ seq_printf(m, "%s %u",
+ mod->name, mod->init_layout.size + mod->core_layout.size);
+ print_unload_info(m, mod);
+
+ /* Informative for users. */
+ seq_printf(m, " %s",
+ mod->state == MODULE_STATE_GOING ? "Unloading" :
+ mod->state == MODULE_STATE_COMING ? "Loading" :
+ "Live");
+ /* Used by oprofile and other similar tools. */
+ value = m->private ? NULL : mod->core_layout.base;
+ seq_printf(m, " 0x%px", value);
+
+ /* Taints info */
+ if (mod->taints)
+ seq_printf(m, " %s", module_flags(mod, buf));
+
+ seq_puts(m, "\n");
+ return 0;
+}
+
+/*
+ * Format: modulename size refcount deps address
+ *
+ * Where refcount is a number or -, and deps is a comma-separated list
+ * of depends or -.
+ */
+static const struct seq_operations modules_op = {
+ .start = m_start,
+ .next = m_next,
+ .stop = m_stop,
+ .show = m_show
+};
+
+/*
+ * This also sets the "private" pointer to non-NULL if the
+ * kernel pointers should be hidden (so you can just test
+ * "m->private" to see if you should keep the values private).
+ *
+ * We use the same logic as for /proc/kallsyms.
+ */
+static int modules_open(struct inode *inode, struct file *file)
+{
+ int err = seq_open(file, &modules_op);
+
+ if (!err) {
+ struct seq_file *m = file->private_data;
+
+ m->private = kallsyms_show_value(file->f_cred) ? NULL : (void *)8ul;
+ }
+
+ return err;
+}
+
+static const struct proc_ops modules_proc_ops = {
+ .proc_flags = PROC_ENTRY_PERMANENT,
+ .proc_open = modules_open,
+ .proc_read = seq_read,
+ .proc_lseek = seq_lseek,
+ .proc_release = seq_release,
+};
+
+static int __init proc_modules_init(void)
+{
+ proc_create("modules", 0, NULL, &modules_proc_ops);
+ return 0;
+}
+module_init(proc_modules_init);
--
2.34.1
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [RFC PATCH v4 11/13] module: Move sysfs support into a separate file
2022-01-30 21:32 [RFC PATCH v4 00/13] module: core code clean up Aaron Tomlin
` (9 preceding siblings ...)
2022-01-30 21:32 ` [RFC PATCH v4 10/13] module: Move procfs " Aaron Tomlin
@ 2022-01-30 21:32 ` Aaron Tomlin
2022-01-30 21:32 ` [RFC PATCH v4 12/13] module: Move kdb_modules list out of core code Aaron Tomlin
` (4 subsequent siblings)
15 siblings, 0 replies; 39+ messages in thread
From: Aaron Tomlin @ 2022-01-30 21:32 UTC (permalink / raw)
To: mcgrof
Cc: cl, pmladek, mbenes, akpm, jeyu, linux-kernel, linux-modules,
live-patching, atomlin, ghalat, allen.lkml, void, joe
No functional change.
This patch migrates module sysfs support out of core code into
kernel/module/sysfs.c. In addition simple code refactoring to
make this possible.
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
kernel/module/Makefile | 1 +
kernel/module/internal.h | 24 ++
kernel/module/main.c | 458 +--------------------------------------
kernel/module/sysfs.c | 425 ++++++++++++++++++++++++++++++++++++
4 files changed, 453 insertions(+), 455 deletions(-)
create mode 100644 kernel/module/sysfs.c
diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index 812f11ad090e..c8982b47b3a2 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -15,4 +15,5 @@ obj-$(CONFIG_STRICT_MODULE_RWX) += strict_rwx.o
obj-$(CONFIG_DEBUG_KMEMLEAK) += debug_kmemleak.o
obj-$(CONFIG_KALLSYMS) += kallsyms.o
obj-$(CONFIG_PROC_FS) += procfs.o
+obj-$(CONFIG_SYSFS) += sysfs.o
endif
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index 09484a9382bc..cf3baca4ebea 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -23,6 +23,9 @@
extern struct mutex module_mutex;
extern struct list_head modules;
+extern struct module_attribute *modinfo_attrs[];
+extern size_t modinfo_attrs_count;
+
/* Provided by the linker */
extern const struct kernel_symbol __start___ksymtab[];
extern const struct kernel_symbol __stop___ksymtab[];
@@ -159,3 +162,24 @@ static inline char *find_kallsyms_symbol(struct module *mod, unsigned long addr,
return NULL;
}
#endif /* CONFIG_KALLSYMS */
+
+#ifdef CONFIG_SYSFS
+extern int mod_sysfs_setup(struct module *mod, const struct load_info *info,
+ struct kernel_param *kparam, unsigned int num_params);
+extern void mod_sysfs_fini(struct module *mod);
+extern void module_remove_modinfo_attrs(struct module *mod, int end);
+extern void del_usage_links(struct module *mod);
+extern void init_param_lock(struct module *mod);
+#else /* !CONFIG_SYSFS */
+static int mod_sysfs_setup(struct module *mod,
+ const struct load_info *info,
+ struct kernel_param *kparam,
+ unsigned int num_params)
+{
+ return 0;
+}
+static inline void mod_sysfs_fini(struct module *mod) { }
+static inline void module_remove_modinfo_attrs(struct module *mod, int end) { }
+static inline void del_usage_links(struct module *mod) { }
+static inline void init_param_lock(struct module *mod) { }
+#endif /* CONFIG_SYSFS */
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 1c20393ab76d..1d16faea82b3 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -13,9 +13,7 @@
#include <linux/trace_events.h>
#include <linux/init.h>
#include <linux/kallsyms.h>
-#include <linux/file.h>
#include <linux/fs.h>
-#include <linux/sysfs.h>
#include <linux/kernel.h>
#include <linux/kernel_read_file.h>
#include <linux/slab.h>
@@ -994,7 +992,7 @@ static ssize_t show_taint(struct module_attribute *mattr,
static struct module_attribute modinfo_taint =
__ATTR(taint, 0444, show_taint, NULL);
-static struct module_attribute *modinfo_attrs[] = {
+struct module_attribute *modinfo_attrs[] = {
&module_uevent,
&modinfo_version,
&modinfo_srcversion,
@@ -1008,6 +1006,8 @@ static struct module_attribute *modinfo_attrs[] = {
NULL,
};
+size_t modinfo_attrs_count = ARRAY_SIZE(modinfo_attrs);
+
static const char vermagic[] = VERMAGIC_STRING;
static int try_to_force_load(struct module *mod, const char *reason)
@@ -1258,458 +1258,6 @@ resolve_symbol_wait(struct module *mod,
return ksym;
}
-/*
- * /sys/module/foo/sections stuff
- * J. Corbet <corbet@lwn.net>
- */
-#ifdef CONFIG_SYSFS
-
-#ifdef CONFIG_KALLSYMS
-struct module_sect_attr {
- struct bin_attribute battr;
- unsigned long address;
-};
-
-struct module_sect_attrs {
- struct attribute_group grp;
- unsigned int nsections;
- struct module_sect_attr attrs[];
-};
-
-static ssize_t module_sect_read(struct file *file, struct kobject *kobj,
- struct bin_attribute *battr,
- char *buf, loff_t pos, size_t count)
-{
- struct module_sect_attr *sattr =
- container_of(battr, struct module_sect_attr, battr);
- char bounce[MODULE_SECT_READ_SIZE + 1];
- size_t wrote;
-
- if (pos != 0)
- return -EINVAL;
-
- /*
- * Since we're a binary read handler, we must account for the
- * trailing NUL byte that sprintf will write: if "buf" is
- * too small to hold the NUL, or the NUL is exactly the last
- * byte, the read will look like it got truncated by one byte.
- * Since there is no way to ask sprintf nicely to not write
- * the NUL, we have to use a bounce buffer.
- */
- wrote = scnprintf(bounce, sizeof(bounce), "0x%px\n",
- kallsyms_show_value(file->f_cred)
- ? (void *)sattr->address : NULL);
- count = min(count, wrote);
- memcpy(buf, bounce, count);
-
- return count;
-}
-
-static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
-{
- unsigned int section;
-
- for (section = 0; section < sect_attrs->nsections; section++)
- kfree(sect_attrs->attrs[section].battr.attr.name);
- kfree(sect_attrs);
-}
-
-static void add_sect_attrs(struct module *mod, const struct load_info *info)
-{
- unsigned int nloaded = 0, i, size[2];
- struct module_sect_attrs *sect_attrs;
- struct module_sect_attr *sattr;
- struct bin_attribute **gattr;
-
- /* Count loaded sections and allocate structures */
- for (i = 0; i < info->hdr->e_shnum; i++)
- if (!sect_empty(&info->sechdrs[i]))
- nloaded++;
- size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded),
- sizeof(sect_attrs->grp.bin_attrs[0]));
- size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.bin_attrs[0]);
- sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
- if (sect_attrs == NULL)
- return;
-
- /* Setup section attributes. */
- sect_attrs->grp.name = "sections";
- sect_attrs->grp.bin_attrs = (void *)sect_attrs + size[0];
-
- sect_attrs->nsections = 0;
- sattr = §_attrs->attrs[0];
- gattr = §_attrs->grp.bin_attrs[0];
- for (i = 0; i < info->hdr->e_shnum; i++) {
- Elf_Shdr *sec = &info->sechdrs[i];
- if (sect_empty(sec))
- continue;
- sysfs_bin_attr_init(&sattr->battr);
- sattr->address = sec->sh_addr;
- sattr->battr.attr.name =
- kstrdup(info->secstrings + sec->sh_name, GFP_KERNEL);
- if (sattr->battr.attr.name == NULL)
- goto out;
- sect_attrs->nsections++;
- sattr->battr.read = module_sect_read;
- sattr->battr.size = MODULE_SECT_READ_SIZE;
- sattr->battr.attr.mode = 0400;
- *(gattr++) = &(sattr++)->battr;
- }
- *gattr = NULL;
-
- if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp))
- goto out;
-
- mod->sect_attrs = sect_attrs;
- return;
- out:
- free_sect_attrs(sect_attrs);
-}
-
-static void remove_sect_attrs(struct module *mod)
-{
- if (mod->sect_attrs) {
- sysfs_remove_group(&mod->mkobj.kobj,
- &mod->sect_attrs->grp);
- /*
- * We are positive that no one is using any sect attrs
- * at this point. Deallocate immediately.
- */
- free_sect_attrs(mod->sect_attrs);
- mod->sect_attrs = NULL;
- }
-}
-
-/*
- * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
- */
-
-struct module_notes_attrs {
- struct kobject *dir;
- unsigned int notes;
- struct bin_attribute attrs[];
-};
-
-static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
- struct bin_attribute *bin_attr,
- char *buf, loff_t pos, size_t count)
-{
- /*
- * The caller checked the pos and count against our size.
- */
- memcpy(buf, bin_attr->private + pos, count);
- return count;
-}
-
-static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
- unsigned int i)
-{
- if (notes_attrs->dir) {
- while (i-- > 0)
- sysfs_remove_bin_file(notes_attrs->dir,
- ¬es_attrs->attrs[i]);
- kobject_put(notes_attrs->dir);
- }
- kfree(notes_attrs);
-}
-
-static void add_notes_attrs(struct module *mod, const struct load_info *info)
-{
- unsigned int notes, loaded, i;
- struct module_notes_attrs *notes_attrs;
- struct bin_attribute *nattr;
-
- /* failed to create section attributes, so can't create notes */
- if (!mod->sect_attrs)
- return;
-
- /* Count notes sections and allocate structures. */
- notes = 0;
- for (i = 0; i < info->hdr->e_shnum; i++)
- if (!sect_empty(&info->sechdrs[i]) &&
- (info->sechdrs[i].sh_type == SHT_NOTE))
- ++notes;
-
- if (notes == 0)
- return;
-
- notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes),
- GFP_KERNEL);
- if (notes_attrs == NULL)
- return;
-
- notes_attrs->notes = notes;
- nattr = ¬es_attrs->attrs[0];
- for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
- if (sect_empty(&info->sechdrs[i]))
- continue;
- if (info->sechdrs[i].sh_type == SHT_NOTE) {
- sysfs_bin_attr_init(nattr);
- nattr->attr.name = mod->sect_attrs->attrs[loaded].battr.attr.name;
- nattr->attr.mode = S_IRUGO;
- nattr->size = info->sechdrs[i].sh_size;
- nattr->private = (void *) info->sechdrs[i].sh_addr;
- nattr->read = module_notes_read;
- ++nattr;
- }
- ++loaded;
- }
-
- notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
- if (!notes_attrs->dir)
- goto out;
-
- for (i = 0; i < notes; ++i)
- if (sysfs_create_bin_file(notes_attrs->dir,
- ¬es_attrs->attrs[i]))
- goto out;
-
- mod->notes_attrs = notes_attrs;
- return;
-
- out:
- free_notes_attrs(notes_attrs, i);
-}
-
-static void remove_notes_attrs(struct module *mod)
-{
- if (mod->notes_attrs)
- free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
-}
-
-#else
-
-static inline void add_sect_attrs(struct module *mod,
- const struct load_info *info)
-{
-}
-
-static inline void remove_sect_attrs(struct module *mod)
-{
-}
-
-static inline void add_notes_attrs(struct module *mod,
- const struct load_info *info)
-{
-}
-
-static inline void remove_notes_attrs(struct module *mod)
-{
-}
-#endif /* CONFIG_KALLSYMS */
-
-static void del_usage_links(struct module *mod)
-{
-#ifdef CONFIG_MODULE_UNLOAD
- struct module_use *use;
-
- mutex_lock(&module_mutex);
- list_for_each_entry(use, &mod->target_list, target_list)
- sysfs_remove_link(use->target->holders_dir, mod->name);
- mutex_unlock(&module_mutex);
-#endif
-}
-
-static int add_usage_links(struct module *mod)
-{
- int ret = 0;
-#ifdef CONFIG_MODULE_UNLOAD
- struct module_use *use;
-
- mutex_lock(&module_mutex);
- list_for_each_entry(use, &mod->target_list, target_list) {
- ret = sysfs_create_link(use->target->holders_dir,
- &mod->mkobj.kobj, mod->name);
- if (ret)
- break;
- }
- mutex_unlock(&module_mutex);
- if (ret)
- del_usage_links(mod);
-#endif
- return ret;
-}
-
-static void module_remove_modinfo_attrs(struct module *mod, int end);
-
-static int module_add_modinfo_attrs(struct module *mod)
-{
- struct module_attribute *attr;
- struct module_attribute *temp_attr;
- int error = 0;
- int i;
-
- mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
- (ARRAY_SIZE(modinfo_attrs) + 1)),
- GFP_KERNEL);
- if (!mod->modinfo_attrs)
- return -ENOMEM;
-
- temp_attr = mod->modinfo_attrs;
- for (i = 0; (attr = modinfo_attrs[i]); i++) {
- if (!attr->test || attr->test(mod)) {
- memcpy(temp_attr, attr, sizeof(*temp_attr));
- sysfs_attr_init(&temp_attr->attr);
- error = sysfs_create_file(&mod->mkobj.kobj,
- &temp_attr->attr);
- if (error)
- goto error_out;
- ++temp_attr;
- }
- }
-
- return 0;
-
-error_out:
- if (i > 0)
- module_remove_modinfo_attrs(mod, --i);
- else
- kfree(mod->modinfo_attrs);
- return error;
-}
-
-static void module_remove_modinfo_attrs(struct module *mod, int end)
-{
- struct module_attribute *attr;
- int i;
-
- for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
- if (end >= 0 && i > end)
- break;
- /* pick a field to test for end of list */
- if (!attr->attr.name)
- break;
- sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
- if (attr->free)
- attr->free(mod);
- }
- kfree(mod->modinfo_attrs);
-}
-
-static void mod_kobject_put(struct module *mod)
-{
- DECLARE_COMPLETION_ONSTACK(c);
- mod->mkobj.kobj_completion = &c;
- kobject_put(&mod->mkobj.kobj);
- wait_for_completion(&c);
-}
-
-static int mod_sysfs_init(struct module *mod)
-{
- int err;
- struct kobject *kobj;
-
- if (!module_sysfs_initialized) {
- pr_err("%s: module sysfs not initialized\n", mod->name);
- err = -EINVAL;
- goto out;
- }
-
- kobj = kset_find_obj(module_kset, mod->name);
- if (kobj) {
- pr_err("%s: module is already loaded\n", mod->name);
- kobject_put(kobj);
- err = -EINVAL;
- goto out;
- }
-
- mod->mkobj.mod = mod;
-
- memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
- mod->mkobj.kobj.kset = module_kset;
- err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
- "%s", mod->name);
- if (err)
- mod_kobject_put(mod);
-
-out:
- return err;
-}
-
-static int mod_sysfs_setup(struct module *mod,
- const struct load_info *info,
- struct kernel_param *kparam,
- unsigned int num_params)
-{
- int err;
-
- err = mod_sysfs_init(mod);
- if (err)
- goto out;
-
- mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
- if (!mod->holders_dir) {
- err = -ENOMEM;
- goto out_unreg;
- }
-
- err = module_param_sysfs_setup(mod, kparam, num_params);
- if (err)
- goto out_unreg_holders;
-
- err = module_add_modinfo_attrs(mod);
- if (err)
- goto out_unreg_param;
-
- err = add_usage_links(mod);
- if (err)
- goto out_unreg_modinfo_attrs;
-
- add_sect_attrs(mod, info);
- add_notes_attrs(mod, info);
-
- return 0;
-
-out_unreg_modinfo_attrs:
- module_remove_modinfo_attrs(mod, -1);
-out_unreg_param:
- module_param_sysfs_remove(mod);
-out_unreg_holders:
- kobject_put(mod->holders_dir);
-out_unreg:
- mod_kobject_put(mod);
-out:
- return err;
-}
-
-static void mod_sysfs_fini(struct module *mod)
-{
- remove_notes_attrs(mod);
- remove_sect_attrs(mod);
- mod_kobject_put(mod);
-}
-
-static void init_param_lock(struct module *mod)
-{
- mutex_init(&mod->param_lock);
-}
-#else /* !CONFIG_SYSFS */
-
-static int mod_sysfs_setup(struct module *mod,
- const struct load_info *info,
- struct kernel_param *kparam,
- unsigned int num_params)
-{
- return 0;
-}
-
-static void mod_sysfs_fini(struct module *mod)
-{
-}
-
-static void module_remove_modinfo_attrs(struct module *mod, int end)
-{
-}
-
-static void del_usage_links(struct module *mod)
-{
-}
-
-static void init_param_lock(struct module *mod)
-{
-}
-#endif /* CONFIG_SYSFS */
-
static void mod_sysfs_teardown(struct module *mod)
{
del_usage_links(mod);
diff --git a/kernel/module/sysfs.c b/kernel/module/sysfs.c
new file mode 100644
index 000000000000..f5c72c567e71
--- /dev/null
+++ b/kernel/module/sysfs.c
@@ -0,0 +1,425 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Module sysfs support
+ *
+ * Copyright (C) 2008 Rusty Russell
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/sysfs.h>
+#include <linux/slab.h>
+#include <linux/kallsyms.h>
+#include <linux/mutex.h>
+#include "internal.h"
+
+/*
+ * /sys/module/foo/sections stuff
+ * J. Corbet <corbet@lwn.net>
+ */
+#ifdef CONFIG_KALLSYMS
+struct module_sect_attr {
+ struct bin_attribute battr;
+ unsigned long address;
+};
+
+struct module_sect_attrs {
+ struct attribute_group grp;
+ unsigned int nsections;
+ struct module_sect_attr attrs[];
+};
+
+static ssize_t module_sect_read(struct file *file, struct kobject *kobj,
+ struct bin_attribute *battr,
+ char *buf, loff_t pos, size_t count)
+{
+ struct module_sect_attr *sattr =
+ container_of(battr, struct module_sect_attr, battr);
+ char bounce[MODULE_SECT_READ_SIZE + 1];
+ size_t wrote;
+
+ if (pos != 0)
+ return -EINVAL;
+
+ /*
+ * Since we're a binary read handler, we must account for the
+ * trailing NUL byte that sprintf will write: if "buf" is
+ * too small to hold the NUL, or the NUL is exactly the last
+ * byte, the read will look like it got truncated by one byte.
+ * Since there is no way to ask sprintf nicely to not write
+ * the NUL, we have to use a bounce buffer.
+ */
+ wrote = scnprintf(bounce, sizeof(bounce), "0x%px\n",
+ kallsyms_show_value(file->f_cred)
+ ? (void *)sattr->address : NULL);
+ count = min(count, wrote);
+ memcpy(buf, bounce, count);
+
+ return count;
+}
+
+static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
+{
+ unsigned int section;
+
+ for (section = 0; section < sect_attrs->nsections; section++)
+ kfree(sect_attrs->attrs[section].battr.attr.name);
+ kfree(sect_attrs);
+}
+
+static void add_sect_attrs(struct module *mod, const struct load_info *info)
+{
+ unsigned int nloaded = 0, i, size[2];
+ struct module_sect_attrs *sect_attrs;
+ struct module_sect_attr *sattr;
+ struct bin_attribute **gattr;
+
+ /* Count loaded sections and allocate structures */
+ for (i = 0; i < info->hdr->e_shnum; i++)
+ if (!sect_empty(&info->sechdrs[i]))
+ nloaded++;
+ size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded),
+ sizeof(sect_attrs->grp.bin_attrs[0]));
+ size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.bin_attrs[0]);
+ sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
+ if (sect_attrs == NULL)
+ return;
+
+ /* Setup section attributes. */
+ sect_attrs->grp.name = "sections";
+ sect_attrs->grp.bin_attrs = (void *)sect_attrs + size[0];
+
+ sect_attrs->nsections = 0;
+ sattr = §_attrs->attrs[0];
+ gattr = §_attrs->grp.bin_attrs[0];
+ for (i = 0; i < info->hdr->e_shnum; i++) {
+ Elf_Shdr *sec = &info->sechdrs[i];
+
+ if (sect_empty(sec))
+ continue;
+ sysfs_bin_attr_init(&sattr->battr);
+ sattr->address = sec->sh_addr;
+ sattr->battr.attr.name =
+ kstrdup(info->secstrings + sec->sh_name, GFP_KERNEL);
+ if (sattr->battr.attr.name == NULL)
+ goto out;
+ sect_attrs->nsections++;
+ sattr->battr.read = module_sect_read;
+ sattr->battr.size = MODULE_SECT_READ_SIZE;
+ sattr->battr.attr.mode = 0400;
+ *(gattr++) = &(sattr++)->battr;
+ }
+ *gattr = NULL;
+
+ if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp))
+ goto out;
+
+ mod->sect_attrs = sect_attrs;
+ return;
+out:
+ free_sect_attrs(sect_attrs);
+}
+
+static void remove_sect_attrs(struct module *mod)
+{
+ if (mod->sect_attrs) {
+ sysfs_remove_group(&mod->mkobj.kobj,
+ &mod->sect_attrs->grp);
+ /*
+ * We are positive that no one is using any sect attrs
+ * at this point. Deallocate immediately.
+ */
+ free_sect_attrs(mod->sect_attrs);
+ mod->sect_attrs = NULL;
+ }
+}
+
+/*
+ * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
+ */
+
+struct module_notes_attrs {
+ struct kobject *dir;
+ unsigned int notes;
+ struct bin_attribute attrs[];
+};
+
+static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
+ struct bin_attribute *bin_attr,
+ char *buf, loff_t pos, size_t count)
+{
+ /*
+ * The caller checked the pos and count against our size.
+ */
+ memcpy(buf, bin_attr->private + pos, count);
+ return count;
+}
+
+static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
+ unsigned int i)
+{
+ if (notes_attrs->dir) {
+ while (i-- > 0)
+ sysfs_remove_bin_file(notes_attrs->dir,
+ ¬es_attrs->attrs[i]);
+ kobject_put(notes_attrs->dir);
+ }
+ kfree(notes_attrs);
+}
+
+static void add_notes_attrs(struct module *mod, const struct load_info *info)
+{
+ unsigned int notes, loaded, i;
+ struct module_notes_attrs *notes_attrs;
+ struct bin_attribute *nattr;
+
+ /* failed to create section attributes, so can't create notes */
+ if (!mod->sect_attrs)
+ return;
+
+ /* Count notes sections and allocate structures. */
+ notes = 0;
+ for (i = 0; i < info->hdr->e_shnum; i++)
+ if (!sect_empty(&info->sechdrs[i]) &&
+ (info->sechdrs[i].sh_type == SHT_NOTE))
+ ++notes;
+
+ if (notes == 0)
+ return;
+
+ notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes),
+ GFP_KERNEL);
+ if (notes_attrs == NULL)
+ return;
+
+ notes_attrs->notes = notes;
+ nattr = ¬es_attrs->attrs[0];
+ for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
+ if (sect_empty(&info->sechdrs[i]))
+ continue;
+ if (info->sechdrs[i].sh_type == SHT_NOTE) {
+ sysfs_bin_attr_init(nattr);
+ nattr->attr.name = mod->sect_attrs->attrs[loaded].battr.attr.name;
+ nattr->attr.mode = 0444;
+ nattr->size = info->sechdrs[i].sh_size;
+ nattr->private = (void *) info->sechdrs[i].sh_addr;
+ nattr->read = module_notes_read;
+ ++nattr;
+ }
+ ++loaded;
+ }
+
+ notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
+ if (!notes_attrs->dir)
+ goto out;
+
+ for (i = 0; i < notes; ++i)
+ if (sysfs_create_bin_file(notes_attrs->dir,
+ ¬es_attrs->attrs[i]))
+ goto out;
+
+ mod->notes_attrs = notes_attrs;
+ return;
+
+out:
+ free_notes_attrs(notes_attrs, i);
+}
+
+static void remove_notes_attrs(struct module *mod)
+{
+ if (mod->notes_attrs)
+ free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
+}
+
+#else /* !CONFIG_KALLSYMS */
+static inline void add_sect_attrs(struct module *mod, const struct load_info *info) { }
+static inline void remove_sect_attrs(struct module *mod) { }
+static inline void add_notes_attrs(struct module *mod, const struct load_info *info) { }
+static inline void remove_notes_attrs(struct module *mod) { }
+#endif /* CONFIG_KALLSYMS */
+
+void del_usage_links(struct module *mod)
+{
+#ifdef CONFIG_MODULE_UNLOAD
+ struct module_use *use;
+
+ mutex_lock(&module_mutex);
+ list_for_each_entry(use, &mod->target_list, target_list)
+ sysfs_remove_link(use->target->holders_dir, mod->name);
+ mutex_unlock(&module_mutex);
+#endif
+}
+
+static int add_usage_links(struct module *mod)
+{
+ int ret = 0;
+#ifdef CONFIG_MODULE_UNLOAD
+ struct module_use *use;
+
+ mutex_lock(&module_mutex);
+ list_for_each_entry(use, &mod->target_list, target_list) {
+ ret = sysfs_create_link(use->target->holders_dir,
+ &mod->mkobj.kobj, mod->name);
+ if (ret)
+ break;
+ }
+ mutex_unlock(&module_mutex);
+ if (ret)
+ del_usage_links(mod);
+#endif
+ return ret;
+}
+
+static int module_add_modinfo_attrs(struct module *mod)
+{
+ struct module_attribute *attr;
+ struct module_attribute *temp_attr;
+ int error = 0;
+ int i;
+
+ mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
+ (modinfo_attrs_count + 1)),
+ GFP_KERNEL);
+ if (!mod->modinfo_attrs)
+ return -ENOMEM;
+
+ temp_attr = mod->modinfo_attrs;
+ for (i = 0; (attr = modinfo_attrs[i]); i++) {
+ if (!attr->test || attr->test(mod)) {
+ memcpy(temp_attr, attr, sizeof(*temp_attr));
+ sysfs_attr_init(&temp_attr->attr);
+ error = sysfs_create_file(&mod->mkobj.kobj,
+ &temp_attr->attr);
+ if (error)
+ goto error_out;
+ ++temp_attr;
+ }
+ }
+
+ return 0;
+
+error_out:
+ if (i > 0)
+ module_remove_modinfo_attrs(mod, --i);
+ else
+ kfree(mod->modinfo_attrs);
+ return error;
+}
+
+void module_remove_modinfo_attrs(struct module *mod, int end)
+{
+ struct module_attribute *attr;
+ int i;
+
+ for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
+ if (end >= 0 && i > end)
+ break;
+ /* pick a field to test for end of list */
+ if (!attr->attr.name)
+ break;
+ sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
+ if (attr->free)
+ attr->free(mod);
+ }
+ kfree(mod->modinfo_attrs);
+}
+
+static void mod_kobject_put(struct module *mod)
+{
+ DECLARE_COMPLETION_ONSTACK(c);
+
+ mod->mkobj.kobj_completion = &c;
+ kobject_put(&mod->mkobj.kobj);
+ wait_for_completion(&c);
+}
+
+static int mod_sysfs_init(struct module *mod)
+{
+ int err;
+ struct kobject *kobj;
+
+ if (!module_sysfs_initialized) {
+ pr_err("%s: module sysfs not initialized\n", mod->name);
+ err = -EINVAL;
+ goto out;
+ }
+
+ kobj = kset_find_obj(module_kset, mod->name);
+ if (kobj) {
+ pr_err("%s: module is already loaded\n", mod->name);
+ kobject_put(kobj);
+ err = -EINVAL;
+ goto out;
+ }
+
+ mod->mkobj.mod = mod;
+
+ memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
+ mod->mkobj.kobj.kset = module_kset;
+ err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
+ "%s", mod->name);
+ if (err)
+ mod_kobject_put(mod);
+
+out:
+ return err;
+}
+
+int mod_sysfs_setup(struct module *mod,
+ const struct load_info *info,
+ struct kernel_param *kparam,
+ unsigned int num_params)
+{
+ int err;
+
+ err = mod_sysfs_init(mod);
+ if (err)
+ goto out;
+
+ mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
+ if (!mod->holders_dir) {
+ err = -ENOMEM;
+ goto out_unreg;
+ }
+
+ err = module_param_sysfs_setup(mod, kparam, num_params);
+ if (err)
+ goto out_unreg_holders;
+
+ err = module_add_modinfo_attrs(mod);
+ if (err)
+ goto out_unreg_param;
+
+ err = add_usage_links(mod);
+ if (err)
+ goto out_unreg_modinfo_attrs;
+
+ add_sect_attrs(mod, info);
+ add_notes_attrs(mod, info);
+
+ return 0;
+
+out_unreg_modinfo_attrs:
+ module_remove_modinfo_attrs(mod, -1);
+out_unreg_param:
+ module_param_sysfs_remove(mod);
+out_unreg_holders:
+ kobject_put(mod->holders_dir);
+out_unreg:
+ mod_kobject_put(mod);
+out:
+ return err;
+}
+
+void mod_sysfs_fini(struct module *mod)
+{
+ remove_notes_attrs(mod);
+ remove_sect_attrs(mod);
+ mod_kobject_put(mod);
+}
+
+void init_param_lock(struct module *mod)
+{
+ mutex_init(&mod->param_lock);
+}
--
2.34.1
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [RFC PATCH v4 12/13] module: Move kdb_modules list out of core code
2022-01-30 21:32 [RFC PATCH v4 00/13] module: core code clean up Aaron Tomlin
` (10 preceding siblings ...)
2022-01-30 21:32 ` [RFC PATCH v4 11/13] module: Move sysfs " Aaron Tomlin
@ 2022-01-30 21:32 ` Aaron Tomlin
2022-01-30 21:32 ` [RFC PATCH v4 13/13] module: Move version support into a separate file Aaron Tomlin
` (3 subsequent siblings)
15 siblings, 0 replies; 39+ messages in thread
From: Aaron Tomlin @ 2022-01-30 21:32 UTC (permalink / raw)
To: mcgrof
Cc: cl, pmladek, mbenes, akpm, jeyu, linux-kernel, linux-modules,
live-patching, atomlin, ghalat, allen.lkml, void, joe
No functional change.
This patch migrates kdb_modules list to core kdb code
since the list of added/or loaded modules is no longer
private.
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
kernel/debug/kdb/kdb_main.c | 5 +++++
kernel/module/main.c | 4 ----
2 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 0852a537dad4..f101f5f078f4 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -59,6 +59,11 @@ EXPORT_SYMBOL(kdb_grepping_flag);
int kdb_grep_leading;
int kdb_grep_trailing;
+#ifdef CONFIG_MODULES
+extern struct list_head modules;
+struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
+#endif /* CONFIG_MODULES */
+
/*
* Kernel debugger state flags
*/
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 1d16faea82b3..59e1c271812c 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -104,10 +104,6 @@ static void mod_update_bounds(struct module *mod)
__mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
}
-#ifdef CONFIG_KGDB_KDB
-struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
-#endif /* CONFIG_KGDB_KDB */
-
static void module_assert_mutex_or_preempt(void)
{
#ifdef CONFIG_LOCKDEP
--
2.34.1
^ permalink raw reply related [flat|nested] 39+ messages in thread
* [RFC PATCH v4 13/13] module: Move version support into a separate file
2022-01-30 21:32 [RFC PATCH v4 00/13] module: core code clean up Aaron Tomlin
` (11 preceding siblings ...)
2022-01-30 21:32 ` [RFC PATCH v4 12/13] module: Move kdb_modules list out of core code Aaron Tomlin
@ 2022-01-30 21:32 ` Aaron Tomlin
2022-02-01 16:44 ` [RFC PATCH v4 00/13] module: core code clean up Allen
` (2 subsequent siblings)
15 siblings, 0 replies; 39+ messages in thread
From: Aaron Tomlin @ 2022-01-30 21:32 UTC (permalink / raw)
To: mcgrof
Cc: cl, pmladek, mbenes, akpm, jeyu, linux-kernel, linux-modules,
live-patching, atomlin, ghalat, allen.lkml, void, joe
No functional change.
This patch migrates module version support out of core code into
kernel/module/version.c. In addition simple code refactoring to
make this possible.
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
kernel/module/Makefile | 1 +
kernel/module/internal.h | 51 +++++++++++++
kernel/module/main.c | 150 +--------------------------------------
kernel/module/version.c | 110 ++++++++++++++++++++++++++++
4 files changed, 164 insertions(+), 148 deletions(-)
create mode 100644 kernel/module/version.c
diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index c8982b47b3a2..6269f4669e47 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -16,4 +16,5 @@ obj-$(CONFIG_DEBUG_KMEMLEAK) += debug_kmemleak.o
obj-$(CONFIG_KALLSYMS) += kallsyms.o
obj-$(CONFIG_PROC_FS) += procfs.o
obj-$(CONFIG_SYSFS) += sysfs.o
+obj-$(CONFIG_MODVERSIONS) += version.o
endif
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index cf3baca4ebea..405e18847730 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -59,7 +59,31 @@ struct load_info {
} index;
};
+struct symsearch {
+ const struct kernel_symbol *start, *stop;
+ const s32 *crcs;
+ enum mod_license {
+ NOT_GPL_ONLY,
+ GPL_ONLY,
+ } license;
+};
+
+struct find_symbol_arg {
+ /* Input */
+ const char *name;
+ bool gplok;
+ bool warn;
+
+ /* Output */
+ struct module *owner;
+ const s32 *crc;
+ const struct kernel_symbol *sym;
+ enum mod_license license;
+};
+
extern int mod_verify_sig(const void *mod, struct load_info *info);
+extern int try_to_force_load(struct module *mod, const char *reason);
+extern bool find_symbol(struct find_symbol_arg *fsa);
extern struct module *find_module_all(const char *name, size_t len, bool even_unformed);
extern unsigned long kernel_symbol_value(const struct kernel_symbol *sym);
extern int cmp_name(const void *name, const void *sym);
@@ -183,3 +207,30 @@ static inline void module_remove_modinfo_attrs(struct module *mod, int end) { }
static inline void del_usage_links(struct module *mod) { }
static inline void init_param_lock(struct module *mod) { }
#endif /* CONFIG_SYSFS */
+
+#ifdef CONFIG_MODVERSIONS
+extern int check_version(const struct load_info *info,
+ const char *symname, struct module *mod, const s32 *crc);
+extern int check_modstruct_version(const struct load_info *info, struct module *mod);
+extern int same_magic(const char *amagic, const char *bmagic, bool has_crcs);
+#else /* !CONFIG_MODVERSIONS */
+static inline int check_version(const struct load_info *info,
+ const char *symname,
+ struct module *mod,
+ const s32 *crc)
+{
+ return 1;
+}
+
+static inline int check_modstruct_version(const struct load_info *info,
+ struct module *mod)
+{
+ return 1;
+}
+
+static inline int same_magic(const char *amagic, const char *bmagic,
+ bool has_crcs)
+{
+ return strcmp(amagic, bmagic) == 0;
+}
+#endif /* CONFIG_MODVERSIONS */
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 59e1c271812c..6b13c17427d8 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -240,28 +240,6 @@ static __maybe_unused void *any_section_objs(const struct load_info *info,
#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
#endif
-struct symsearch {
- const struct kernel_symbol *start, *stop;
- const s32 *crcs;
- enum mod_license {
- NOT_GPL_ONLY,
- GPL_ONLY,
- } license;
-};
-
-struct find_symbol_arg {
- /* Input */
- const char *name;
- bool gplok;
- bool warn;
-
- /* Output */
- struct module *owner;
- const s32 *crc;
- const struct kernel_symbol *sym;
- enum mod_license license;
-};
-
static bool check_exported_symbol(const struct symsearch *syms,
struct module *owner,
unsigned int symnum, void *data)
@@ -332,7 +310,7 @@ static bool find_exported_symbol_in_section(const struct symsearch *syms,
* Find an exported symbol and return it, along with, (optional) crc and
* (optional) module which owns it. Needs preempt disabled or module_mutex.
*/
-static bool find_symbol(struct find_symbol_arg *fsa)
+bool find_symbol(struct find_symbol_arg *fsa)
{
static const struct symsearch arr[] = {
{ __start___ksymtab, __stop___ksymtab, __start___kcrctab,
@@ -1006,7 +984,7 @@ size_t modinfo_attrs_count = ARRAY_SIZE(modinfo_attrs);
static const char vermagic[] = VERMAGIC_STRING;
-static int try_to_force_load(struct module *mod, const char *reason)
+int try_to_force_load(struct module *mod, const char *reason)
{
#ifdef CONFIG_MODULE_FORCE_LOAD
if (!test_taint(TAINT_FORCED_MODULE))
@@ -1018,115 +996,6 @@ static int try_to_force_load(struct module *mod, const char *reason)
#endif
}
-#ifdef CONFIG_MODVERSIONS
-
-static u32 resolve_rel_crc(const s32 *crc)
-{
- return *(u32 *)((void *)crc + *crc);
-}
-
-static int check_version(const struct load_info *info,
- const char *symname,
- struct module *mod,
- const s32 *crc)
-{
- Elf_Shdr *sechdrs = info->sechdrs;
- unsigned int versindex = info->index.vers;
- unsigned int i, num_versions;
- struct modversion_info *versions;
-
- /* Exporting module didn't supply crcs? OK, we're already tainted. */
- if (!crc)
- return 1;
-
- /* No versions at all? modprobe --force does this. */
- if (versindex == 0)
- return try_to_force_load(mod, symname) == 0;
-
- versions = (void *) sechdrs[versindex].sh_addr;
- num_versions = sechdrs[versindex].sh_size
- / sizeof(struct modversion_info);
-
- for (i = 0; i < num_versions; i++) {
- u32 crcval;
-
- if (strcmp(versions[i].name, symname) != 0)
- continue;
-
- if (IS_ENABLED(CONFIG_MODULE_REL_CRCS))
- crcval = resolve_rel_crc(crc);
- else
- crcval = *crc;
- if (versions[i].crc == crcval)
- return 1;
- pr_debug("Found checksum %X vs module %lX\n",
- crcval, versions[i].crc);
- goto bad_version;
- }
-
- /* Broken toolchain. Warn once, then let it go.. */
- pr_warn_once("%s: no symbol version for %s\n", info->name, symname);
- return 1;
-
-bad_version:
- pr_warn("%s: disagrees about version of symbol %s\n",
- info->name, symname);
- return 0;
-}
-
-static inline int check_modstruct_version(const struct load_info *info,
- struct module *mod)
-{
- struct find_symbol_arg fsa = {
- .name = "module_layout",
- .gplok = true,
- };
-
- /*
- * Since this should be found in kernel (which can't be removed), no
- * locking is necessary -- use preempt_disable() to placate lockdep.
- */
- preempt_disable();
- if (!find_symbol(&fsa)) {
- preempt_enable();
- BUG();
- }
- preempt_enable();
- return check_version(info, "module_layout", mod, fsa.crc);
-}
-
-/* First part is kernel version, which we ignore if module has crcs. */
-static inline int same_magic(const char *amagic, const char *bmagic,
- bool has_crcs)
-{
- if (has_crcs) {
- amagic += strcspn(amagic, " ");
- bmagic += strcspn(bmagic, " ");
- }
- return strcmp(amagic, bmagic) == 0;
-}
-#else
-static inline int check_version(const struct load_info *info,
- const char *symname,
- struct module *mod,
- const s32 *crc)
-{
- return 1;
-}
-
-static inline int check_modstruct_version(const struct load_info *info,
- struct module *mod)
-{
- return 1;
-}
-
-static inline int same_magic(const char *amagic, const char *bmagic,
- bool has_crcs)
-{
- return strcmp(amagic, bmagic) == 0;
-}
-#endif /* CONFIG_MODVERSIONS */
-
static char *get_modinfo(const struct load_info *info, const char *tag);
static char *get_next_modinfo(const struct load_info *info, const char *tag,
char *prev);
@@ -3238,18 +3107,3 @@ void print_modules(void)
pr_cont(" [last unloaded: %s]", last_unloaded_module);
pr_cont("\n");
}
-
-#ifdef CONFIG_MODVERSIONS
-/*
- * Generate the signature for all relevant module structures here.
- * If these change, we don't want to try to parse the module.
- */
-void module_layout(struct module *mod,
- struct modversion_info *ver,
- struct kernel_param *kp,
- struct kernel_symbol *ks,
- struct tracepoint * const *tp)
-{
-}
-EXPORT_SYMBOL(module_layout);
-#endif
diff --git a/kernel/module/version.c b/kernel/module/version.c
new file mode 100644
index 000000000000..10a1490d1b9e
--- /dev/null
+++ b/kernel/module/version.c
@@ -0,0 +1,110 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Module version support
+ *
+ * Copyright (C) 2008 Rusty Russell
+ */
+
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/printk.h>
+#include "internal.h"
+
+static u32 resolve_rel_crc(const s32 *crc)
+{
+ return *(u32 *)((void *)crc + *crc);
+}
+
+int check_version(const struct load_info *info,
+ const char *symname,
+ struct module *mod,
+ const s32 *crc)
+{
+ Elf_Shdr *sechdrs = info->sechdrs;
+ unsigned int versindex = info->index.vers;
+ unsigned int i, num_versions;
+ struct modversion_info *versions;
+
+ /* Exporting module didn't supply crcs? OK, we're already tainted. */
+ if (!crc)
+ return 1;
+
+ /* No versions at all? modprobe --force does this. */
+ if (versindex == 0)
+ return try_to_force_load(mod, symname) == 0;
+
+ versions = (void *) sechdrs[versindex].sh_addr;
+ num_versions = sechdrs[versindex].sh_size
+ / sizeof(struct modversion_info);
+
+ for (i = 0; i < num_versions; i++) {
+ u32 crcval;
+
+ if (strcmp(versions[i].name, symname) != 0)
+ continue;
+
+ if (IS_ENABLED(CONFIG_MODULE_REL_CRCS))
+ crcval = resolve_rel_crc(crc);
+ else
+ crcval = *crc;
+ if (versions[i].crc == crcval)
+ return 1;
+ pr_debug("Found checksum %X vs module %lX\n",
+ crcval, versions[i].crc);
+ goto bad_version;
+ }
+
+ /* Broken toolchain. Warn once, then let it go.. */
+ pr_warn_once("%s: no symbol version for %s\n", info->name, symname);
+ return 1;
+
+bad_version:
+ pr_warn("%s: disagrees about version of symbol %s\n",
+ info->name, symname);
+ return 0;
+}
+
+inline int check_modstruct_version(const struct load_info *info,
+ struct module *mod)
+{
+ struct find_symbol_arg fsa = {
+ .name = "module_layout",
+ .gplok = true,
+ };
+
+ /*
+ * Since this should be found in kernel (which can't be removed), no
+ * locking is necessary -- use preempt_disable() to placate lockdep.
+ */
+ preempt_disable();
+ if (!find_symbol(&fsa)) {
+ preempt_enable();
+ BUG();
+ }
+ preempt_enable();
+ return check_version(info, "module_layout", mod, fsa.crc);
+}
+
+/* First part is kernel version, which we ignore if module has crcs. */
+inline int same_magic(const char *amagic, const char *bmagic,
+ bool has_crcs)
+{
+ if (has_crcs) {
+ amagic += strcspn(amagic, " ");
+ bmagic += strcspn(bmagic, " ");
+ }
+ return strcmp(amagic, bmagic) == 0;
+}
+
+/*
+ * Generate the signature for all relevant module structures here.
+ * If these change, we don't want to try to parse the module.
+ */
+void module_layout(struct module *mod,
+ struct modversion_info *ver,
+ struct kernel_param *kp,
+ struct kernel_symbol *ks,
+ struct tracepoint * const *tp)
+{
+}
+EXPORT_SYMBOL(module_layout);
--
2.34.1
^ permalink raw reply related [flat|nested] 39+ messages in thread
* Re: [RFC PATCH v4 00/13] module: core code clean up
2022-01-30 21:32 [RFC PATCH v4 00/13] module: core code clean up Aaron Tomlin
` (12 preceding siblings ...)
2022-01-30 21:32 ` [RFC PATCH v4 13/13] module: Move version support into a separate file Aaron Tomlin
@ 2022-02-01 16:44 ` Allen
2022-02-05 20:33 ` Aaron Tomlin
2022-02-02 2:44 ` Luis Chamberlain
2022-02-03 0:20 ` Luis Chamberlain
15 siblings, 1 reply; 39+ messages in thread
From: Allen @ 2022-02-01 16:44 UTC (permalink / raw)
To: Aaron Tomlin
Cc: Luis Chamberlain, Christoph Lameter, Petr Mladek, Miroslav Benes,
Andrew Morton, jeyu, Linux Kernel Mailing List, linux-modules,
live-patching, atomlin, ghalat, void, Joe Perches
Thanks Aaron for V4.
Build/boot test on qemu. Running more tests on BM.
Thanks.
On Sun, Jan 30, 2022 at 1:32 PM Aaron Tomlin <atomlin@redhat.com> wrote:
>
> Hi Luis,
>
> As per your suggestion [1], this is an attempt to refactor and split
> optional code out of core module support code into separate components.
> This version is based on branch mcgrof/modules-next since a97ac8cb24a3/or
> modules-5.17-rc1. Please let me know your thoughts.
>
> Changes since v1 [2]:
>
> - Moved module version support code into a new file
>
> Changes since v2 [3]:
>
> - Moved module decompress support to a separate file
> - Made check_modinfo_livepatch() generic (Petr Mladek)
> - Removed filename from each newly created file (Luis Chamberlain)
> - Addressed some (i.e. --ignore=ASSIGN_IN_IF,AVOID_BUG was used)
> minor scripts/checkpatch.pl concerns e.g., use strscpy over
> strlcpy and missing a blank line after declarations (Allen)
>
> Changes since v3 [4]:
>
> - Refactored both is_livepatch_module() and set_livepatch_module(),
> respectively, to use IS_ENABLED(CONFIG_LIVEPATCH) (Joe Perches)
> - Addressed various compiler warnings e.g., no previous prototype (0-day)
>
> [1]: https://lore.kernel.org/lkml/YbEZ4HgSYQEPuRmS@bombadil.infradead.org/
> [2]: https://lore.kernel.org/lkml/20211228213041.1356334-1-atomlin@redhat.com/
> [3]: https://lore.kernel.org/lkml/20220106234319.2067842-1-atomlin@redhat.com/
> [4]: https://lore.kernel.org/lkml/20220128203934.600247-1-atomlin@redhat.com/
>
> Aaron Tomlin (13):
> module: Move all into module/
> module: Simple refactor in preparation for split
> module: Move livepatch support to a separate file
> module: Move latched RB-tree support to a separate file
> module: Move arch strict rwx support to a separate file
> module: Move strict rwx support to a separate file
> module: Move extra signature support out of core code
> module: Move kmemleak support to a separate file
> module: Move kallsyms support into a separate file
> module: Move procfs support into a separate file
> module: Move sysfs support into a separate file
> module: Move kdb_modules list out of core code
> module: Move version support into a separate file
>
> MAINTAINERS | 2 +-
> include/linux/module.h | 64 +-
> kernel/Makefile | 5 +-
> kernel/debug/kdb/kdb_main.c | 5 +
> kernel/module-internal.h | 50 -
> kernel/module/Makefile | 20 +
> kernel/module/arch_strict_rwx.c | 44 +
> kernel/module/debug_kmemleak.c | 30 +
> .../decompress.c} | 2 +-
> kernel/module/internal.h | 236 +++
> kernel/module/kallsyms.c | 502 +++++
> kernel/module/livepatch.c | 74 +
> kernel/{module.c => module/main.c} | 1874 +----------------
> kernel/module/procfs.c | 142 ++
> .../signature.c} | 0
> kernel/module/signing.c | 120 ++
> kernel/module/strict_rwx.c | 83 +
> kernel/module/sysfs.c | 425 ++++
> kernel/module/tree_lookup.c | 109 +
> kernel/module/version.c | 110 +
> kernel/module_signing.c | 45 -
> 21 files changed, 2038 insertions(+), 1904 deletions(-)
> delete mode 100644 kernel/module-internal.h
> create mode 100644 kernel/module/Makefile
> create mode 100644 kernel/module/arch_strict_rwx.c
> create mode 100644 kernel/module/debug_kmemleak.c
> rename kernel/{module_decompress.c => module/decompress.c} (99%)
> create mode 100644 kernel/module/internal.h
> create mode 100644 kernel/module/kallsyms.c
> create mode 100644 kernel/module/livepatch.c
> rename kernel/{module.c => module/main.c} (63%)
> create mode 100644 kernel/module/procfs.c
> rename kernel/{module_signature.c => module/signature.c} (100%)
> create mode 100644 kernel/module/signing.c
> create mode 100644 kernel/module/strict_rwx.c
> create mode 100644 kernel/module/sysfs.c
> create mode 100644 kernel/module/tree_lookup.c
> create mode 100644 kernel/module/version.c
> delete mode 100644 kernel/module_signing.c
>
>
> base-commit: a97ac8cb24a3c3ad74794adb83717ef1605d1b47
> --
> 2.34.1
>
--
- Allen
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [RFC PATCH v4 00/13] module: core code clean up
2022-01-30 21:32 [RFC PATCH v4 00/13] module: core code clean up Aaron Tomlin
` (13 preceding siblings ...)
2022-02-01 16:44 ` [RFC PATCH v4 00/13] module: core code clean up Allen
@ 2022-02-02 2:44 ` Luis Chamberlain
2022-02-06 14:40 ` Aaron Tomlin
2022-02-03 0:20 ` Luis Chamberlain
15 siblings, 1 reply; 39+ messages in thread
From: Luis Chamberlain @ 2022-02-02 2:44 UTC (permalink / raw)
To: Aaron Tomlin
Cc: cl, pmladek, mbenes, akpm, jeyu, linux-kernel, linux-modules,
live-patching, atomlin, ghalat, allen.lkml, void, joe
On Sun, Jan 30, 2022 at 09:32:01PM +0000, Aaron Tomlin wrote:
> Hi Luis,
>
> As per your suggestion [1], this is an attempt to refactor and split
> optional code out of core module support code into separate components.
> This version is based on branch mcgrof/modules-next since a97ac8cb24a3/or
> modules-5.17-rc1. Please let me know your thoughts.
Nice, can you get this tested with 0day? You can ask for your tree to
be tested, see:
https://01.org/lkp/documentation/0-day-test-service
See the question, "Which git tree and which mailing list will be tested?
How can I opt-in or opt-out from it?"
LUis
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [RFC PATCH v4 00/13] module: core code clean up
2022-01-30 21:32 [RFC PATCH v4 00/13] module: core code clean up Aaron Tomlin
` (14 preceding siblings ...)
2022-02-02 2:44 ` Luis Chamberlain
@ 2022-02-03 0:20 ` Luis Chamberlain
2022-02-03 7:48 ` Christophe Leroy
` (5 more replies)
15 siblings, 6 replies; 39+ messages in thread
From: Luis Chamberlain @ 2022-02-03 0:20 UTC (permalink / raw)
To: Aaron Tomlin, Christophe Leroy, Michal Suchanek
Cc: cl, pmladek, mbenes, akpm, jeyu, linux-kernel, linux-modules,
live-patching, atomlin, ghalat, allen.lkml, void, joe
On Sun, Jan 30, 2022 at 09:32:01PM +0000, Aaron Tomlin wrote:
> Hi Luis,
>
> As per your suggestion [1], this is an attempt to refactor and split
> optional code out of core module support code into separate components.
> This version is based on branch mcgrof/modules-next since a97ac8cb24a3/or
> modules-5.17-rc1. Please let me know your thoughts.
>
> Changes since v1 [2]:
Thanks for all this work Aaron! Can you drop the RFC prefix,
rebase onto linus' latest tree (as he already merged my
modules-next, so his tree is more up to date), and submit again?
I'll then apply this to my modules-next, and then ask Christophe to
rebase on top of that.
Michal, you'd be up next if you want to go through modules-next.
Aaron, please Cc Christophe and Michal on your next respin.
Thanks!!
Luis
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [RFC PATCH v4 00/13] module: core code clean up
2022-02-03 0:20 ` Luis Chamberlain
@ 2022-02-03 7:48 ` Christophe Leroy
2022-02-06 14:45 ` Aaron Tomlin
2022-02-03 18:01 ` Christophe Leroy
` (4 subsequent siblings)
5 siblings, 1 reply; 39+ messages in thread
From: Christophe Leroy @ 2022-02-03 7:48 UTC (permalink / raw)
To: Luis Chamberlain, Aaron Tomlin, Michal Suchanek
Cc: cl, pmladek, mbenes, akpm, jeyu, linux-kernel, linux-modules,
live-patching, atomlin, ghalat, allen.lkml, void, joe
Le 03/02/2022 à 01:20, Luis Chamberlain a écrit :
> On Sun, Jan 30, 2022 at 09:32:01PM +0000, Aaron Tomlin wrote:
>> Hi Luis,
>>
>> As per your suggestion [1], this is an attempt to refactor and split
>> optional code out of core module support code into separate components.
>> This version is based on branch mcgrof/modules-next since a97ac8cb24a3/or
>> modules-5.17-rc1. Please let me know your thoughts.
>>
>> Changes since v1 [2]:
>
> Thanks for all this work Aaron! Can you drop the RFC prefix,
> rebase onto linus' latest tree (as he already merged my
> modules-next, so his tree is more up to date), and submit again?
>
> I'll then apply this to my modules-next, and then ask Christophe to
> rebase on top of that.
>
> Michal, you'd be up next if you want to go through modules-next.
>
> Aaron, please Cc Christophe and Michal on your next respin.
>
I went quickly through v4. That's a great and useful job I think, it
should ease future work on modules. So I will be happy to apply my
changes on top of this series.
I may have more comments after reviewing in more details and rebasing my
series on top of it, but at the time being I have at least one comment:
All function prototypes in header files are pointlessly prepended with
'extern' keyword. This was done that way in the old days, but has been
deprecated as this keyword does nothing on function prototypes but adds
visual pollution when looking at the files.
See below the output of checkpatch on internal.h
Regardless, I'm looking forward to rebasing my series on top of yours.
Thanks
Christophe
WARNING: Use #include <linux/module.h> instead of <asm/module.h>
#10: FILE: kernel/module/internal.h:10:
+#include <asm/module.h>
CHECK: spaces preferred around that '-' (ctx:VxV)
#18: FILE: kernel/module/internal.h:18:
+#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
^
CHECK: extern prototypes should be avoided in .h files
#84: FILE: kernel/module/internal.h:84:
+extern int mod_verify_sig(const void *mod, struct load_info *info);
CHECK: extern prototypes should be avoided in .h files
#85: FILE: kernel/module/internal.h:85:
+extern int try_to_force_load(struct module *mod, const char *reason);
CHECK: extern prototypes should be avoided in .h files
#86: FILE: kernel/module/internal.h:86:
+extern bool find_symbol(struct find_symbol_arg *fsa);
CHECK: extern prototypes should be avoided in .h files
#87: FILE: kernel/module/internal.h:87:
+extern struct module *find_module_all(const char *name, size_t len,
bool even_unformed);
CHECK: extern prototypes should be avoided in .h files
#88: FILE: kernel/module/internal.h:88:
+extern unsigned long kernel_symbol_value(const struct kernel_symbol *sym);
CHECK: extern prototypes should be avoided in .h files
#89: FILE: kernel/module/internal.h:89:
+extern int cmp_name(const void *name, const void *sym);
CHECK: extern prototypes should be avoided in .h files
#90: FILE: kernel/module/internal.h:90:
+extern long get_offset(struct module *mod, unsigned int *size, Elf_Shdr
*sechdr,
CHECK: extern prototypes should be avoided in .h files
#92: FILE: kernel/module/internal.h:92:
+extern char *module_flags(struct module *mod, char *buf);
CHECK: extern prototypes should be avoided in .h files
#95: FILE: kernel/module/internal.h:95:
+extern int copy_module_elf(struct module *mod, struct load_info *info);
CHECK: extern prototypes should be avoided in .h files
#96: FILE: kernel/module/internal.h:96:
+extern void free_module_elf(struct module *mod);
CHECK: Please use a blank line after function/struct/union/enum declarations
#102: FILE: kernel/module/internal.h:102:
+}
+static inline void free_module_elf(struct module *mod) { }
CHECK: Please use a blank line after function/struct/union/enum declarations
#114: FILE: kernel/module/internal.h:114:
+}
+static inline void module_decompress_cleanup(struct load_info *info)
CHECK: extern prototypes should be avoided in .h files
#128: FILE: kernel/module/internal.h:128:
+extern void mod_tree_insert(struct module *mod);
CHECK: extern prototypes should be avoided in .h files
#129: FILE: kernel/module/internal.h:129:
+extern void mod_tree_remove_init(struct module *mod);
CHECK: extern prototypes should be avoided in .h files
#130: FILE: kernel/module/internal.h:130:
+extern void mod_tree_remove(struct module *mod);
CHECK: extern prototypes should be avoided in .h files
#131: FILE: kernel/module/internal.h:131:
+extern struct module *mod_find(unsigned long addr);
ERROR: do not initialise statics to 0
#133: FILE: kernel/module/internal.h:133:
+static unsigned long module_addr_min = -1UL, module_addr_max = 0;
CHECK: extern prototypes should be avoided in .h files
#153: FILE: kernel/module/internal.h:153:
+extern int module_sig_check(struct load_info *info, int flags);
CHECK: extern prototypes should be avoided in .h files
#162: FILE: kernel/module/internal.h:162:
+extern void kmemleak_load_module(const struct module *mod, const struct
load_info *info);
CHECK: extern prototypes should be avoided in .h files
#170: FILE: kernel/module/internal.h:170:
+extern void init_build_id(struct module *mod, const struct load_info
*info);
CHECK: extern prototypes should be avoided in .h files
#175: FILE: kernel/module/internal.h:175:
+extern void layout_symtab(struct module *mod, struct load_info *info);
CHECK: extern prototypes should be avoided in .h files
#176: FILE: kernel/module/internal.h:176:
+extern void add_kallsyms(struct module *mod, const struct load_info *info);
CHECK: extern prototypes should be avoided in .h files
#177: FILE: kernel/module/internal.h:177:
+extern bool sect_empty(const Elf_Shdr *sect);
CHECK: extern prototypes should be avoided in .h files
#178: FILE: kernel/module/internal.h:178:
+extern const char *find_kallsyms_symbol(struct module *mod, unsigned
long addr,
CHECK: extern prototypes should be avoided in .h files
#191: FILE: kernel/module/internal.h:191:
+extern int mod_sysfs_setup(struct module *mod, const struct load_info
*info,
CHECK: extern prototypes should be avoided in .h files
#193: FILE: kernel/module/internal.h:193:
+extern void mod_sysfs_fini(struct module *mod);
CHECK: extern prototypes should be avoided in .h files
#194: FILE: kernel/module/internal.h:194:
+extern void module_remove_modinfo_attrs(struct module *mod, int end);
CHECK: extern prototypes should be avoided in .h files
#195: FILE: kernel/module/internal.h:195:
+extern void del_usage_links(struct module *mod);
CHECK: extern prototypes should be avoided in .h files
#196: FILE: kernel/module/internal.h:196:
+extern void init_param_lock(struct module *mod);
CHECK: Please use a blank line after function/struct/union/enum declarations
#205: FILE: kernel/module/internal.h:205:
+}
+static inline void mod_sysfs_fini(struct module *mod) { }
CHECK: extern prototypes should be avoided in .h files
#212: FILE: kernel/module/internal.h:212:
+extern int check_version(const struct load_info *info,
CHECK: extern prototypes should be avoided in .h files
#214: FILE: kernel/module/internal.h:214:
+extern int check_modstruct_version(const struct load_info *info, struct
module *mod);
CHECK: extern prototypes should be avoided in .h files
#215: FILE: kernel/module/internal.h:215:
+extern int same_magic(const char *amagic, const char *bmagic, bool
has_crcs);
CHECK: Alignment should match open parenthesis
#232: FILE: kernel/module/internal.h:232:
+static inline int same_magic(const char *amagic, const char *bmagic,
+ bool has_crcs)
total: 1 errors, 1 warnings, 34 checks, 236 lines checked
NOTE: For some of the reported defects, checkpatch may be able to
mechanically convert to the typical style using --fix or
--fix-inplace.
kernel/module/internal.h has style problems, please review.
NOTE: If any of the errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [RFC PATCH v4 00/13] module: core code clean up
2022-02-03 0:20 ` Luis Chamberlain
2022-02-03 7:48 ` Christophe Leroy
@ 2022-02-03 18:01 ` Christophe Leroy
2022-02-06 16:54 ` Aaron Tomlin
2022-02-07 16:46 ` Aaron Tomlin
2022-02-03 18:15 ` Christophe Leroy
` (3 subsequent siblings)
5 siblings, 2 replies; 39+ messages in thread
From: Christophe Leroy @ 2022-02-03 18:01 UTC (permalink / raw)
To: Luis Chamberlain, Aaron Tomlin, Michal Suchanek
Cc: cl, pmladek, mbenes, akpm, jeyu, linux-kernel, linux-modules,
live-patching, atomlin, ghalat, allen.lkml, void, joe
Le 03/02/2022 à 01:20, Luis Chamberlain a écrit :
> On Sun, Jan 30, 2022 at 09:32:01PM +0000, Aaron Tomlin wrote:
>> Hi Luis,
>>
>> As per your suggestion [1], this is an attempt to refactor and split
>> optional code out of core module support code into separate components.
>> This version is based on branch mcgrof/modules-next since a97ac8cb24a3/or
>> modules-5.17-rc1. Please let me know your thoughts.
>>
>> Changes since v1 [2]:
>
I have another comment: I think patch 5 should be dropped.
Having something behave based on a CONFIG_ARCH_HAS_SOMETHING item is
wrong. It is not because a plateform selects
CONFIG_ARCH_HAS_STRICT_MODULE_RWX that the module core should behave
differentely than with other platforms as far as the user has not
selected CONFIG_STRICT_MODULE_RWX.
And the topic here is wrong. It is a coincidence if making that stuff
depend on CONFIG_ARCH_HAS_STRICT_MODULE_RWX works. This is just because
the only architectures that do the module allocation without Exec flag
are architectures that have also selected
CONFIG_ARCH_HAS_STRICT_MODULE_RWX. But it should also work on other
architectures.
I don't know exactly what was the motivation for commit 93651f80dcb6
("modules: fix compile error if don't have strict module rwx") at the
first place but it is just wrong and we should fix it.
module_enable_x() should work just fine regardless of
CONFIG_ARCH_HAS_STRICT_MODULE_RWX.
Thanks
Christophe
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [RFC PATCH v4 00/13] module: core code clean up
2022-02-03 0:20 ` Luis Chamberlain
2022-02-03 7:48 ` Christophe Leroy
2022-02-03 18:01 ` Christophe Leroy
@ 2022-02-03 18:15 ` Christophe Leroy
2022-02-06 16:57 ` Aaron Tomlin
2022-02-03 19:43 ` Michal Suchánek
` (2 subsequent siblings)
5 siblings, 1 reply; 39+ messages in thread
From: Christophe Leroy @ 2022-02-03 18:15 UTC (permalink / raw)
To: Luis Chamberlain, Aaron Tomlin, Michal Suchanek
Cc: cl, pmladek, mbenes, akpm, jeyu, linux-kernel, linux-modules,
live-patching, atomlin, ghalat, allen.lkml, void, joe
Le 03/02/2022 à 01:20, Luis Chamberlain a écrit :
> On Sun, Jan 30, 2022 at 09:32:01PM +0000, Aaron Tomlin wrote:
>> Hi Luis,
>>
>> As per your suggestion [1], this is an attempt to refactor and split
>> optional code out of core module support code into separate components.
>> This version is based on branch mcgrof/modules-next since a97ac8cb24a3/or
>> modules-5.17-rc1. Please let me know your thoughts.
>>
I also have the feeling that a lot of stuff like function prototypes you
added in include/linux/module.h should instead go in
kernel/module/internal.h as they are not used outside of kernel/module/
Christophe
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [RFC PATCH v4 00/13] module: core code clean up
2022-02-03 0:20 ` Luis Chamberlain
` (2 preceding siblings ...)
2022-02-03 18:15 ` Christophe Leroy
@ 2022-02-03 19:43 ` Michal Suchánek
2022-02-03 20:13 ` Luis Chamberlain
2022-02-03 20:10 ` Luis Chamberlain
2022-02-06 14:42 ` Aaron Tomlin
5 siblings, 1 reply; 39+ messages in thread
From: Michal Suchánek @ 2022-02-03 19:43 UTC (permalink / raw)
To: Luis Chamberlain
Cc: Aaron Tomlin, Christophe Leroy, cl, pmladek, mbenes, akpm, jeyu,
linux-kernel, linux-modules, live-patching, atomlin, ghalat,
allen.lkml, void, joe
Hello,
On Wed, Feb 02, 2022 at 04:20:41PM -0800, Luis Chamberlain wrote:
> On Sun, Jan 30, 2022 at 09:32:01PM +0000, Aaron Tomlin wrote:
> > Hi Luis,
> >
> > As per your suggestion [1], this is an attempt to refactor and split
> > optional code out of core module support code into separate components.
> > This version is based on branch mcgrof/modules-next since a97ac8cb24a3/or
> > modules-5.17-rc1. Please let me know your thoughts.
> >
> > Changes since v1 [2]:
>
> Thanks for all this work Aaron! Can you drop the RFC prefix,
> rebase onto linus' latest tree (as he already merged my
> modules-next, so his tree is more up to date), and submit again?
>
> I'll then apply this to my modules-next, and then ask Christophe to
> rebase on top of that.
>
> Michal, you'd be up next if you want to go through modules-next.
Sounds like a good idea. When rebasing on top of 5.17-rc1 the only
conflict was on the module code.
Thanks
Michal
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [RFC PATCH v4 00/13] module: core code clean up
2022-02-03 0:20 ` Luis Chamberlain
` (3 preceding siblings ...)
2022-02-03 19:43 ` Michal Suchánek
@ 2022-02-03 20:10 ` Luis Chamberlain
2022-02-06 17:00 ` Aaron Tomlin
2022-02-06 14:42 ` Aaron Tomlin
5 siblings, 1 reply; 39+ messages in thread
From: Luis Chamberlain @ 2022-02-03 20:10 UTC (permalink / raw)
To: Aaron Tomlin, Christophe Leroy, Michal Suchanek
Cc: cl, pmladek, mbenes, akpm, jeyu, linux-kernel, linux-modules,
live-patching, atomlin, ghalat, allen.lkml, void, joe
On Wed, Feb 02, 2022 at 04:20:41PM -0800, Luis Chamberlain wrote:
> On Sun, Jan 30, 2022 at 09:32:01PM +0000, Aaron Tomlin wrote:
> > Hi Luis,
> >
> > As per your suggestion [1], this is an attempt to refactor and split
> > optional code out of core module support code into separate components.
> > This version is based on branch mcgrof/modules-next since a97ac8cb24a3/or
> > modules-5.17-rc1. Please let me know your thoughts.
> >
> > Changes since v1 [2]:
>
> Thanks for all this work Aaron! Can you drop the RFC prefix,
> rebase onto linus' latest tree (as he already merged my
> modules-next, so his tree is more up to date), and submit again?
Linus now merged the fix in question, just be sure to use his
latest tree, it should include 67d6212afda218d564890d1674bab28e8612170f
> I'll then apply this to my modules-next, and then ask Christophe to
> rebase on top of that.
If you can fix the issues from your patches which Christophe mentioned
that would be great. Then I'll apply then and then Christophe can work
off of that.
> Michal, you'd be up next if you want to go through modules-next.
Luis
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [RFC PATCH v4 00/13] module: core code clean up
2022-02-03 19:43 ` Michal Suchánek
@ 2022-02-03 20:13 ` Luis Chamberlain
0 siblings, 0 replies; 39+ messages in thread
From: Luis Chamberlain @ 2022-02-03 20:13 UTC (permalink / raw)
To: Michal Suchánek
Cc: Aaron Tomlin, Christophe Leroy, cl, pmladek, mbenes, akpm, jeyu,
linux-kernel, linux-modules, live-patching, atomlin, ghalat,
allen.lkml, void, joe
On Thu, Feb 03, 2022 at 08:43:17PM +0100, Michal Suchánek wrote:
> Hello,
>
> On Wed, Feb 02, 2022 at 04:20:41PM -0800, Luis Chamberlain wrote:
> > On Sun, Jan 30, 2022 at 09:32:01PM +0000, Aaron Tomlin wrote:
> > > Hi Luis,
> > >
> > > As per your suggestion [1], this is an attempt to refactor and split
> > > optional code out of core module support code into separate components.
> > > This version is based on branch mcgrof/modules-next since a97ac8cb24a3/or
> > > modules-5.17-rc1. Please let me know your thoughts.
> > >
> > > Changes since v1 [2]:
> >
> > Thanks for all this work Aaron! Can you drop the RFC prefix,
> > rebase onto linus' latest tree (as he already merged my
> > modules-next, so his tree is more up to date), and submit again?
> >
> > I'll then apply this to my modules-next, and then ask Christophe to
> > rebase on top of that.
> >
> > Michal, you'd be up next if you want to go through modules-next.
>
> Sounds like a good idea. When rebasing on top of 5.17-rc1 the only
> conflict was on the module code.
I'll let you know once modules-next is ready for your code. But before
that, does anyone have any objections with this code going through
modules-next? Although its kexec related it touches on a lot of
kernel/module.c and if we don't take it on modules-next I'm afraid
there will be quite a bit of conflicts there later.
Luis
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [RFC PATCH v4 00/13] module: core code clean up
2022-02-01 16:44 ` [RFC PATCH v4 00/13] module: core code clean up Allen
@ 2022-02-05 20:33 ` Aaron Tomlin
0 siblings, 0 replies; 39+ messages in thread
From: Aaron Tomlin @ 2022-02-05 20:33 UTC (permalink / raw)
To: Allen
Cc: Aaron Tomlin, Luis Chamberlain, Christoph Lameter, Petr Mladek,
Miroslav Benes, Andrew Morton, jeyu, Linux Kernel Mailing List,
linux-modules, live-patching, ghalat, void, Joe Perches
On Tue 2022-02-01 08:44 -0800, Allen wrote:
> Build/boot test on qemu. Running more tests on BM.
Thanks Allen.
Kind regards,
--
Aaron Tomlin
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [RFC PATCH v4 00/13] module: core code clean up
2022-02-02 2:44 ` Luis Chamberlain
@ 2022-02-06 14:40 ` Aaron Tomlin
0 siblings, 0 replies; 39+ messages in thread
From: Aaron Tomlin @ 2022-02-06 14:40 UTC (permalink / raw)
To: Luis Chamberlain
Cc: cl, pmladek, mbenes, akpm, jeyu, linux-kernel, linux-modules,
live-patching, atomlin, ghalat, allen.lkml, void, joe
On Tue 2022-02-01 18:44 -0800, Luis Chamberlain wrote:
> Nice, can you get this tested with 0day? You can ask for your tree to
> be tested, see:
>
> https://01.org/lkp/documentation/0-day-test-service
>
> See the question, "Which git tree and which mailing list will be tested?
> How can I opt-in or opt-out from it?"
Thanks for this information Luis.
Kind regards,
--
Aaron Tomlin
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [RFC PATCH v4 00/13] module: core code clean up
2022-02-03 0:20 ` Luis Chamberlain
` (4 preceding siblings ...)
2022-02-03 20:10 ` Luis Chamberlain
@ 2022-02-06 14:42 ` Aaron Tomlin
5 siblings, 0 replies; 39+ messages in thread
From: Aaron Tomlin @ 2022-02-06 14:42 UTC (permalink / raw)
To: Luis Chamberlain
Cc: Christophe Leroy, Michal Suchanek, cl, pmladek, mbenes, akpm,
jeyu, linux-kernel, linux-modules, live-patching, atomlin,
ghalat, allen.lkml, void, joe
On Wed 2022-02-02 16:20 -0800, Luis Chamberlain wrote:
> Thanks for all this work Aaron! Can you drop the RFC prefix,
> rebase onto linus' latest tree (as he already merged my
> modules-next, so his tree is more up to date), and submit again?
No problem and will do.
> I'll then apply this to my modules-next, and then ask Christophe to
> rebase on top of that.
>
> Michal, you'd be up next if you want to go through modules-next.
>
> Aaron, please Cc Christophe and Michal on your next respin.
Sure.
Kind regards,
--
Aaron Tomlin
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [RFC PATCH v4 00/13] module: core code clean up
2022-02-03 7:48 ` Christophe Leroy
@ 2022-02-06 14:45 ` Aaron Tomlin
0 siblings, 0 replies; 39+ messages in thread
From: Aaron Tomlin @ 2022-02-06 14:45 UTC (permalink / raw)
To: Christophe Leroy
Cc: Luis Chamberlain, Michal Suchanek, cl, pmladek, mbenes, akpm,
jeyu, linux-kernel, linux-modules, live-patching, atomlin,
ghalat, allen.lkml, void, joe
On Thu 2022-02-03 07:48 +0000, Christophe Leroy wrote:
> All function prototypes in header files are pointlessly prepended with
> 'extern' keyword. This was done that way in the old days, but has been
> deprecated as this keyword does nothing on function prototypes but adds
> visual pollution when looking at the files.
Christophe,
Firstly, thanks for your initial feedback.
I will address the above.
Kind regards,
--
Aaron Tomlin
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [RFC PATCH v4 00/13] module: core code clean up
2022-02-03 18:01 ` Christophe Leroy
@ 2022-02-06 16:54 ` Aaron Tomlin
2022-02-07 16:46 ` Aaron Tomlin
1 sibling, 0 replies; 39+ messages in thread
From: Aaron Tomlin @ 2022-02-06 16:54 UTC (permalink / raw)
To: Christophe Leroy
Cc: Luis Chamberlain, Michal Suchanek, cl, pmladek, mbenes, akpm,
jeyu, linux-kernel, linux-modules, live-patching, atomlin,
ghalat, allen.lkml, void, joe
On Thu 2022-02-03 18:01 +0000, Christophe Leroy wrote:
> I have another comment: I think patch 5 should be dropped.
Fair enough.
> Having something behave based on a CONFIG_ARCH_HAS_SOMETHING item is
> wrong. It is not because a plateform selects
> CONFIG_ARCH_HAS_STRICT_MODULE_RWX that the module core should behave
> differentely than with other platforms as far as the user has not
> selected CONFIG_STRICT_MODULE_RWX.
>
> And the topic here is wrong. It is a coincidence if making that stuff
> depend on CONFIG_ARCH_HAS_STRICT_MODULE_RWX works. This is just because
> the only architectures that do the module allocation without Exec flag
> are architectures that have also selected
> CONFIG_ARCH_HAS_STRICT_MODULE_RWX. But it should also work on other
> architectures.
>
> I don't know exactly what was the motivation for commit 93651f80dcb6
> ("modules: fix compile error if don't have strict module rwx") at the
> first place but it is just wrong and we should fix it.
>
> module_enable_x() should work just fine regardless of
> CONFIG_ARCH_HAS_STRICT_MODULE_RWX.
The above does make sense, to me.
Kind regards,
--
Aaron Tomlin
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [RFC PATCH v4 00/13] module: core code clean up
2022-02-03 18:15 ` Christophe Leroy
@ 2022-02-06 16:57 ` Aaron Tomlin
0 siblings, 0 replies; 39+ messages in thread
From: Aaron Tomlin @ 2022-02-06 16:57 UTC (permalink / raw)
To: Christophe Leroy
Cc: Luis Chamberlain, Michal Suchanek, cl, pmladek, mbenes, akpm,
jeyu, linux-kernel, linux-modules, live-patching, atomlin,
ghalat, allen.lkml, void, joe
On Thu 2022-02-03 18:15 +0000, Christophe Leroy wrote:
> I also have the feeling that a lot of stuff like function prototypes you
> added in include/linux/module.h should instead go in
> kernel/module/internal.h as they are not used outside of kernel/module/
Agreed - this will be reflected in v5.
Kind regards,
--
Aaron Tomlin
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [RFC PATCH v4 00/13] module: core code clean up
2022-02-03 20:10 ` Luis Chamberlain
@ 2022-02-06 17:00 ` Aaron Tomlin
0 siblings, 0 replies; 39+ messages in thread
From: Aaron Tomlin @ 2022-02-06 17:00 UTC (permalink / raw)
To: Luis Chamberlain
Cc: Christophe Leroy, Michal Suchanek, cl, pmladek, mbenes, akpm,
jeyu, linux-kernel, linux-modules, live-patching, atomlin,
ghalat, allen.lkml, void, joe
On Thu 2022-02-03 12:10 -0800, Luis Chamberlain wrote:
> Linus now merged the fix in question, just be sure to use his
> latest tree, it should include 67d6212afda218d564890d1674bab28e8612170f
Hi Luis,
Sure, will do.
> If you can fix the issues from your patches which Christophe mentioned
> that would be great. Then I'll apply then and then Christophe can work
> off of that.
All right. I will try to complete this shortly.
Kind regards,
--
Aaron Tomlin
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [RFC PATCH v4 00/13] module: core code clean up
2022-02-03 18:01 ` Christophe Leroy
2022-02-06 16:54 ` Aaron Tomlin
@ 2022-02-07 16:46 ` Aaron Tomlin
2022-02-07 17:17 ` Christophe Leroy
1 sibling, 1 reply; 39+ messages in thread
From: Aaron Tomlin @ 2022-02-07 16:46 UTC (permalink / raw)
To: Christophe Leroy
Cc: Luis Chamberlain, Aaron Tomlin, Michal Suchanek, cl, pmladek,
mbenes, akpm, jeyu, linux-kernel, linux-modules, live-patching,
ghalat, allen.lkml, void, joe
On Thu 2022-02-03 18:01 +0000, Christophe Leroy wrote:
> I don't know exactly what was the motivation for commit 93651f80dcb6
> ("modules: fix compile error if don't have strict module rwx") at the
> first place but it is just wrong and we should fix it.
Christophe,
I think we are in agreement. If I understand correctly, it should not be
possible to enable CONFIG_STRICT_MODULE_RWX without
CONFIG_ARCH_HAS_STRICT_MODULE_RWX (or inversely), as per arch/Kconfig:
config STRICT_MODULE_RWX
bool "Set loadable kernel module data as NX and text as RO" if ARCH_OPTIONAL_KERNEL_RWX
depends on ARCH_HAS_STRICT_MODULE_RWX && MODULES
default !ARCH_OPTIONAL_KERNEL_RWX || ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
The objective of Linus' commit ad21fc4faa2a1 ("arch: Move
CONFIG_DEBUG_RODATA and CONFIG_SET_MODULE_RONX to be common") and in
particular commit 0f5bf6d0afe4b ("arch: Rename CONFIG_DEBUG_RODATA and
CONFIG_DEBUG_MODULE_RONX") does seem correct. So, architectures that would
prefer to make this feature selectable rather than enabled by default
should continue to have this option.
> module_enable_x() should work just fine regardless of
> CONFIG_ARCH_HAS_STRICT_MODULE_RWX.
As per the above, we should fix commit 93651f80dcb6 ("modules: fix compile
error if don't have strict module rwx") so a stub for module_enable_x()
would no longer be required, right?
Kind regards,
--
Aaron Tomlin
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [RFC PATCH v4 00/13] module: core code clean up
2022-02-07 16:46 ` Aaron Tomlin
@ 2022-02-07 17:17 ` Christophe Leroy
2022-02-07 18:01 ` Aaron Tomlin
0 siblings, 1 reply; 39+ messages in thread
From: Christophe Leroy @ 2022-02-07 17:17 UTC (permalink / raw)
To: Aaron Tomlin
Cc: Luis Chamberlain, Aaron Tomlin, Michal Suchanek, cl, pmladek,
mbenes, akpm, jeyu, linux-kernel, linux-modules, live-patching,
ghalat, allen.lkml, void, joe
Le 07/02/2022 à 17:46, Aaron Tomlin a écrit :
> On Thu 2022-02-03 18:01 +0000, Christophe Leroy wrote:
>> I don't know exactly what was the motivation for commit 93651f80dcb6
>> ("modules: fix compile error if don't have strict module rwx") at the
>> first place but it is just wrong and we should fix it.
>
> Christophe,
>
> I think we are in agreement. If I understand correctly, it should not be
> possible to enable CONFIG_STRICT_MODULE_RWX without
> CONFIG_ARCH_HAS_STRICT_MODULE_RWX (or inversely), as per arch/Kconfig:
>
> config STRICT_MODULE_RWX
> bool "Set loadable kernel module data as NX and text as RO" if ARCH_OPTIONAL_KERNEL_RWX
> depends on ARCH_HAS_STRICT_MODULE_RWX && MODULES
> default !ARCH_OPTIONAL_KERNEL_RWX || ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
>
> The objective of Linus' commit ad21fc4faa2a1 ("arch: Move
> CONFIG_DEBUG_RODATA and CONFIG_SET_MODULE_RONX to be common") and in
> particular commit 0f5bf6d0afe4b ("arch: Rename CONFIG_DEBUG_RODATA and
> CONFIG_DEBUG_MODULE_RONX") does seem correct. So, architectures that would
> prefer to make this feature selectable rather than enabled by default
> should continue to have this option.
>
>> module_enable_x() should work just fine regardless of
>> CONFIG_ARCH_HAS_STRICT_MODULE_RWX.
>
> As per the above, we should fix commit 93651f80dcb6 ("modules: fix compile
> error if don't have strict module rwx") so a stub for module_enable_x()
> would no longer be required, right?
>
Yes and that's the purpose of the patch I proposed at
https://patchwork.kernel.org/project/linux-modules/patch/203348805c9ac9851d8939d15cb9802ef047b5e2.1643919758.git.christophe.leroy@csgroup.eu/
Allthough I need to find out what's the problem reported by the robot.
As suggested by Luis, this fix should go once all ongoing work is done.
But it would be nice if you could just remove patch 5 from you series,
otherwise we would have to revert it later.
Thanks
Christophe
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [RFC PATCH v4 00/13] module: core code clean up
2022-02-07 17:17 ` Christophe Leroy
@ 2022-02-07 18:01 ` Aaron Tomlin
2022-02-08 7:50 ` Christophe Leroy
0 siblings, 1 reply; 39+ messages in thread
From: Aaron Tomlin @ 2022-02-07 18:01 UTC (permalink / raw)
To: Christophe Leroy
Cc: Aaron Tomlin, Luis Chamberlain, Michal Suchanek, cl, pmladek,
mbenes, akpm, jeyu, linux-kernel, linux-modules, live-patching,
ghalat, allen.lkml, void, joe
On Mon 2022-02-07 17:17 +0000, Christophe Leroy wrote:
> Yes and that's the purpose of the patch I proposed at
> https://patchwork.kernel.org/project/linux-modules/patch/203348805c9ac9851d8939d15cb9802ef047b5e2.1643919758.git.christophe.leroy@csgroup.eu/
I see.
> Allthough I need to find out what's the problem reported by the robot.
I'll have a look too.
> As suggested by Luis, this fix should go once all ongoing work is done.
> But it would be nice if you could just remove patch 5 from you series,
> otherwise we would have to revert it later.
Perhaps it might be easier if I keep the patch within the series; once
merged into module-next, by Luis, you can rebase and then add the "Fixes:"
tag to resolve the issue, no?
Kind regards,
--
Aaron Tomlin
^ permalink raw reply [flat|nested] 39+ messages in thread
* RE: [RFC PATCH v4 00/13] module: core code clean up
2022-02-07 18:01 ` Aaron Tomlin
@ 2022-02-08 7:50 ` Christophe Leroy
2022-02-08 10:05 ` Aaron Tomlin
0 siblings, 1 reply; 39+ messages in thread
From: Christophe Leroy @ 2022-02-08 7:50 UTC (permalink / raw)
To: Aaron Tomlin
Cc: Aaron Tomlin, Luis Chamberlain, Michal Suchanek, cl, pmladek,
mbenes, akpm, jeyu, linux-kernel, linux-modules, live-patching,
ghalat, allen.lkml, void, joe
> -----Message d'origine-----
> De : Aaron Tomlin <atomlin@redhat.com>
> Envoyé : lundi 7 février 2022 19:02
> À : Christophe Leroy <christophe.leroy@csgroup.eu>
> Cc : Aaron Tomlin <atomlin@atomlin.com>; Luis Chamberlain
> <mcgrof@kernel.org>; Michal Suchanek <msuchanek@suse.de>; cl@linux.com;
> pmladek@suse.com; mbenes@suse.cz; akpm@linux-foundation.org;
> jeyu@kernel.org; linux-kernel@vger.kernel.org; linux-modules@vger.kernel.org;
> live-patching@vger.kernel.org; ghalat@redhat.com; allen.lkml@gmail.com;
> void@manifault.com; joe@perches.com
> Objet : Re: [RFC PATCH v4 00/13] module: core code clean up
>
> On Mon 2022-02-07 17:17 +0000, Christophe Leroy wrote:
> > Yes and that's the purpose of the patch I proposed at
> > https://patchwork.kernel.org/project/linux-
> modules/patch/203348805c9ac9851d8939d15cb9802ef047b5e2.1643919758.gi
> t.christophe.leroy@csgroup.eu/
>
> I see.
>
> > Allthough I need to find out what's the problem reported by the robot.
>
> I'll have a look too.
>
> > As suggested by Luis, this fix should go once all ongoing work is done.
> > But it would be nice if you could just remove patch 5 from you series,
> > otherwise we would have to revert it later.
>
> Perhaps it might be easier if I keep the patch within the series; once
> merged into module-next, by Luis, you can rebase and then add the "Fixes:"
> tag to resolve the issue, no?
I don't think it is easier.
If we do that it means we'll move some code from main.c to arch_strict_rwx.c with your series, then move it back to main.c and remove arch_strict_rwx.c when we do the fix. That's not good for history tracking because the code we move back and forth will appear as new code in main.c whereas it's code that has been there for years.
As we know the code will be back in main.c at the end, I looks easier to me to not move it at all by not applying your patch 5.
Thanks
Christophe
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [RFC PATCH v4 00/13] module: core code clean up
2022-02-08 7:50 ` Christophe Leroy
@ 2022-02-08 10:05 ` Aaron Tomlin
0 siblings, 0 replies; 39+ messages in thread
From: Aaron Tomlin @ 2022-02-08 10:05 UTC (permalink / raw)
To: Christophe Leroy
Cc: Aaron Tomlin, Luis Chamberlain, Michal Suchanek, cl, pmladek,
mbenes, akpm, jeyu, linux-kernel, linux-modules, live-patching,
ghalat, allen.lkml, void, joe
On Tue 2022-02-08 07:50 +0000, Christophe Leroy wrote:
> As we know the code will be back in main.c at the end, I looks easier to
> me to not move it at all by not applying your patch 5.
Looking at your proposed solution once again, I do agree now.
Kind regards,
--
Aaron Tomlin
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [RFC PATCH v4 03/13] module: Move livepatch support to a separate file
2022-01-30 21:32 ` [RFC PATCH v4 03/13] module: Move livepatch support to a separate file Aaron Tomlin
@ 2022-02-08 11:42 ` Petr Mladek
2022-02-08 15:18 ` Aaron Tomlin
0 siblings, 1 reply; 39+ messages in thread
From: Petr Mladek @ 2022-02-08 11:42 UTC (permalink / raw)
To: Aaron Tomlin
Cc: mcgrof, cl, mbenes, akpm, jeyu, linux-kernel, linux-modules,
live-patching, atomlin, ghalat, allen.lkml, void, joe
On Sun 2022-01-30 21:32:04, Aaron Tomlin wrote:
> No functional change.
>
> This patch migrates livepatch support (i.e. used during module
> add/or load and remove/or deletion) from core module code into
> kernel/module/livepatch.c. At the moment it contains code to
> persist Elf information about a given livepatch module, only.
>
> diff --git a/include/linux/module.h b/include/linux/module.h
> index f4338235ed2c..c7daac4d16ee 100644
> --- a/include/linux/module.h
> +++ b/include/linux/module.h
> @@ -663,17 +663,23 @@ static inline bool module_requested_async_probing(struct module *module)
> return module && module->async_probe_requested;
> }
>
> -#ifdef CONFIG_LIVEPATCH
> static inline bool is_livepatch_module(struct module *mod)
> {
> - return mod->klp;
> + if (IS_ENABLED(CONFIG_LIVEPATCH)) {
> + if (mod->klp)
> + return true;
> + }
> + return false;
The following is easier to follow for me. But it is a matter of taste.
Feel free to use whatever you prefer.
return IS_ENABLED(CONFIG_LIVEPATCH) && mod->klp;
> }
> -#else /* !CONFIG_LIVEPATCH */
> -static inline bool is_livepatch_module(struct module *mod)
> +
> +static inline bool set_livepatch_module(struct module *mod)
> {
> + if (IS_ENABLED(CONFIG_LIVEPATCH)) {
> + mod->klp = true;
> + return true;
> + }
> return false;
This should go to internal.h.
Alternative is to move both is_livepatch_module() and
set_livepatch_module() into include/linux/livepatch.h.
I do not have strong opinion.
> }
> -#endif /* CONFIG_LIVEPATCH */
>
> bool is_module_sig_enforced(void);
> void set_module_sig_enforced(void);
Otherwise, it looks good to me.
Best Regards,
Petr
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [RFC PATCH v4 03/13] module: Move livepatch support to a separate file
2022-02-08 11:42 ` Petr Mladek
@ 2022-02-08 15:18 ` Aaron Tomlin
0 siblings, 0 replies; 39+ messages in thread
From: Aaron Tomlin @ 2022-02-08 15:18 UTC (permalink / raw)
To: Petr Mladek
Cc: mcgrof, cl, mbenes, akpm, jeyu, linux-kernel, linux-modules,
live-patching, atomlin, ghalat, allen.lkml, void, joe
On Tue 2022-02-08 12:42 +0100, Petr Mladek wrote:
> This should go to internal.h.
>
> Alternative is to move both is_livepatch_module() and
> set_livepatch_module() into include/linux/livepatch.h.
>
> I do not have strong opinion.
Hi Petr,
Firstly, thank you for your feedback.
In my opinion, I believe is_livepatch_module() should remain as it may
continue to be used externally i.e., outside of kernel/module/; albeit,
indeed set_livepatch_module() should be moved to kernel/module/internal.h
given its use is exclusive to core code.
Kind regards,
--
Aaron Tomlin
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [RFC PATCH v4 07/13] module: Move extra signature support out of core code
2022-01-30 21:32 ` [RFC PATCH v4 07/13] module: Move extra signature support out of core code Aaron Tomlin
@ 2022-02-09 14:28 ` Miroslav Benes
2022-02-09 14:37 ` Aaron Tomlin
0 siblings, 1 reply; 39+ messages in thread
From: Miroslav Benes @ 2022-02-09 14:28 UTC (permalink / raw)
To: Aaron Tomlin
Cc: mcgrof, cl, pmladek, akpm, jeyu, linux-kernel, linux-modules,
live-patching, atomlin, ghalat, allen.lkml, void, joe
> diff --git a/include/linux/module.h b/include/linux/module.h
> index 520c0f4bb968..15ba2ebbca3e 100644
> --- a/include/linux/module.h
> +++ b/include/linux/module.h
> @@ -720,8 +720,8 @@ static inline bool set_livepatch_module(struct module *mod)
> return false;
> }
>
> -bool is_module_sig_enforced(void);
> -void set_module_sig_enforced(void);
> +extern bool is_module_sig_enforced(void);
> +extern void set_module_sig_enforced(void);
Please, drop these extern modifiers in front of function declarations.
They are unnecessary. It applies to different patches of the set as well.
> #else /* !CONFIG_MODULES... */
>
> @@ -911,6 +911,7 @@ static inline bool module_sig_ok(struct module *module)
> {
> return true;
> }
> +#define sig_enforce false
> #endif /* CONFIG_MODULE_SIG */
>
> int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
> diff --git a/kernel/module/internal.h b/kernel/module/internal.h
> index de28d6bb7b5b..2ec2a1d9dd9f 100644
> --- a/kernel/module/internal.h
> +++ b/kernel/module/internal.h
> @@ -114,3 +114,12 @@ static struct module *mod_find(unsigned long addr)
> return NULL;
> }
> #endif /* CONFIG_MODULES_TREE_LOOKUP */
> +
> +#ifdef CONFIG_MODULE_SIG
> +extern int module_sig_check(struct load_info *info, int flags);
> +#else /* !CONFIG_MODULE_SIG */
> +static int module_sig_check(struct load_info *info, int flags)
> +{
> + return 0;
> +}
I think it should be
static inline int module_sig_check(struct load_info *info, int flags)
Thanks,
Miroslav
^ permalink raw reply [flat|nested] 39+ messages in thread
* Re: [RFC PATCH v4 07/13] module: Move extra signature support out of core code
2022-02-09 14:28 ` Miroslav Benes
@ 2022-02-09 14:37 ` Aaron Tomlin
0 siblings, 0 replies; 39+ messages in thread
From: Aaron Tomlin @ 2022-02-09 14:37 UTC (permalink / raw)
To: Miroslav Benes
Cc: Aaron Tomlin, mcgrof, cl, pmladek, akpm, jeyu, linux-kernel,
linux-modules, live-patching, ghalat, allen.lkml, void, joe
On Wed 2022-02-09 15:28 +0100, Miroslav Benes wrote:
> Please, drop these extern modifiers in front of function declarations.
> They are unnecessary. It applies to different patches of the set as well.
Agreed - this was suggested previously.
The next iteration should be published soon. Just waiting on 0-day.
> > +#ifdef CONFIG_MODULE_SIG
> > +extern int module_sig_check(struct load_info *info, int flags);
> > +#else /* !CONFIG_MODULE_SIG */
> > +static int module_sig_check(struct load_info *info, int flags)
> > +{
> > + return 0;
> > +}
>
> I think it should be
> static inline int module_sig_check(struct load_info *info, int flags)
Yes, indeed it should. Thanks for the feedback.
Kind regards,
--
Aaron Tomlin
^ permalink raw reply [flat|nested] 39+ messages in thread
end of thread, other threads:[~2022-02-09 14:40 UTC | newest]
Thread overview: 39+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-01-30 21:32 [RFC PATCH v4 00/13] module: core code clean up Aaron Tomlin
2022-01-30 21:32 ` [RFC PATCH v4 01/13] module: Move all into module/ Aaron Tomlin
2022-01-30 21:32 ` [RFC PATCH v4 02/13] module: Simple refactor in preparation for split Aaron Tomlin
2022-01-30 21:32 ` [RFC PATCH v4 03/13] module: Move livepatch support to a separate file Aaron Tomlin
2022-02-08 11:42 ` Petr Mladek
2022-02-08 15:18 ` Aaron Tomlin
2022-01-30 21:32 ` [RFC PATCH v4 04/13] module: Move latched RB-tree " Aaron Tomlin
2022-01-30 21:32 ` [RFC PATCH v4 05/13] module: Move arch strict rwx " Aaron Tomlin
2022-01-30 21:32 ` [RFC PATCH v4 06/13] module: Move " Aaron Tomlin
2022-01-30 21:32 ` [RFC PATCH v4 07/13] module: Move extra signature support out of core code Aaron Tomlin
2022-02-09 14:28 ` Miroslav Benes
2022-02-09 14:37 ` Aaron Tomlin
2022-01-30 21:32 ` [RFC PATCH v4 08/13] module: Move kmemleak support to a separate file Aaron Tomlin
2022-01-30 21:32 ` [RFC PATCH v4 09/13] module: Move kallsyms support into " Aaron Tomlin
2022-01-30 21:32 ` [RFC PATCH v4 10/13] module: Move procfs " Aaron Tomlin
2022-01-30 21:32 ` [RFC PATCH v4 11/13] module: Move sysfs " Aaron Tomlin
2022-01-30 21:32 ` [RFC PATCH v4 12/13] module: Move kdb_modules list out of core code Aaron Tomlin
2022-01-30 21:32 ` [RFC PATCH v4 13/13] module: Move version support into a separate file Aaron Tomlin
2022-02-01 16:44 ` [RFC PATCH v4 00/13] module: core code clean up Allen
2022-02-05 20:33 ` Aaron Tomlin
2022-02-02 2:44 ` Luis Chamberlain
2022-02-06 14:40 ` Aaron Tomlin
2022-02-03 0:20 ` Luis Chamberlain
2022-02-03 7:48 ` Christophe Leroy
2022-02-06 14:45 ` Aaron Tomlin
2022-02-03 18:01 ` Christophe Leroy
2022-02-06 16:54 ` Aaron Tomlin
2022-02-07 16:46 ` Aaron Tomlin
2022-02-07 17:17 ` Christophe Leroy
2022-02-07 18:01 ` Aaron Tomlin
2022-02-08 7:50 ` Christophe Leroy
2022-02-08 10:05 ` Aaron Tomlin
2022-02-03 18:15 ` Christophe Leroy
2022-02-06 16:57 ` Aaron Tomlin
2022-02-03 19:43 ` Michal Suchánek
2022-02-03 20:13 ` Luis Chamberlain
2022-02-03 20:10 ` Luis Chamberlain
2022-02-06 17:00 ` Aaron Tomlin
2022-02-06 14:42 ` Aaron Tomlin
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