* [PATCH v5 1/2] kallsyms: move kallsyms_show_value() out of kallsyms.c
[not found] <CGME20230608033132epcas5p22208020abf46fc8667086c31b6d7c63d@epcas5p2.samsung.com>
@ 2023-06-08 3:31 ` Maninder Singh
[not found] ` <CGME20230608033140epcas5p1a1a04da5a0c78f888afbf54b00519f1e@epcas5p1.samsung.com>
0 siblings, 1 reply; 3+ messages in thread
From: Maninder Singh @ 2023-06-08 3:31 UTC (permalink / raw)
To: ast, daniel, john.fastabend, andrii, martin.lau, song, yhs,
kpsingh, sdf, haoluo, jolsa, thunder.leizhen, mcgrof, boqun.feng,
vincenzopalazzodev, ojeda, jgross, brauner, michael.christie,
samitolvanen, glider, peterz, keescook, stephen.s.brennan,
alan.maguire, pmladek
Cc: linux-kernel, bpf, Maninder Singh, Onkarnath
function kallsyms_show_value() is used by other parts
like modules_open(), kprobes_read() etc. which can work in case of
!KALLSYMS also.
e.g. as of now lsmod do not show module address if KALLSYMS is disabled.
since kallsyms_show_value() defination is not present, it returns false
in !KALLSYMS.
/ # lsmod
test 12288 0 - Live 0x0000000000000000 (O)
So kallsyms_show_value() can be made generic
without dependency on KALLSYMS.
Thus moving out function to a new file ksyms_common.c.
With this patch code is just moved to new file
and no functional change.
Co-developed-by: Onkarnath <onkarnath.1@samsung.com>
Signed-off-by: Onkarnath <onkarnath.1@samsung.com>
Signed-off-by: Maninder Singh <maninder1.s@samsung.com>
Reviewed-by: Zhen Lei <thunder.leizhen@huawei.com>
---
earlier conversations:(then it has dependancy on other change, but that
was stashed from linux-next, now it can be pushed)
https://lore.kernel.org/lkml/202205111525.92B1C597@keescook/T/
https://lkml.org/lkml/2022/4/13/47
v1 -> v2: separate out bpf and kallsyms change
v2 -> v3: make kallsym changes in2 patches, non functional and
functional change
v3 -> v4: patch order changed, file name changed form knosyms -> ksyms_common
and copyright header modified.
v4 -> v5: license changed to kallsyms.c file, and bpf changes are
dropped as confirmed from BPF side:
https://lore.kernel.org/lkml/CAEf4Bzb4B9FxMnf3t81D22FWkciLOvwDPLY0BbEPGGe7R5QPrg@mail.gmail.com/T/
kernel/Makefile | 2 +-
kernel/kallsyms.c | 35 ---------------------------------
kernel/ksyms_common.c | 45 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 46 insertions(+), 36 deletions(-)
create mode 100644 kernel/ksyms_common.c
diff --git a/kernel/Makefile b/kernel/Makefile
index f9e3fd9195d9..3947122d618b 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -10,7 +10,7 @@ obj-y = fork.o exec_domain.o panic.o \
extable.o params.o \
kthread.o sys_ni.o nsproxy.o \
notifier.o ksysfs.o cred.o reboot.o \
- async.o range.o smpboot.o ucount.o regset.o
+ async.o range.o smpboot.o ucount.o regset.o ksyms_common.o
obj-$(CONFIG_USERMODE_DRIVER) += usermode_driver.o
obj-$(CONFIG_MULTIUSER) += groups.o
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 8193e947aa10..0f82c3d5a57d 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -907,41 +907,6 @@ late_initcall(bpf_ksym_iter_register);
#endif /* CONFIG_BPF_SYSCALL */
-static inline int kallsyms_for_perf(void)
-{
-#ifdef CONFIG_PERF_EVENTS
- extern int sysctl_perf_event_paranoid;
- if (sysctl_perf_event_paranoid <= 1)
- return 1;
-#endif
- return 0;
-}
-
-/*
- * We show kallsyms information even to normal users if we've enabled
- * kernel profiling and are explicitly not paranoid (so kptr_restrict
- * is clear, and sysctl_perf_event_paranoid isn't set).
- *
- * Otherwise, require CAP_SYSLOG (assuming kptr_restrict isn't set to
- * block even that).
- */
-bool kallsyms_show_value(const struct cred *cred)
-{
- switch (kptr_restrict) {
- case 0:
- if (kallsyms_for_perf())
- return true;
- fallthrough;
- case 1:
- if (security_capable(cred, &init_user_ns, CAP_SYSLOG,
- CAP_OPT_NOAUDIT) == 0)
- return true;
- fallthrough;
- default:
- return false;
- }
-}
-
static int kallsyms_open(struct inode *inode, struct file *file)
{
/*
diff --git a/kernel/ksyms_common.c b/kernel/ksyms_common.c
new file mode 100644
index 000000000000..3840fa1c9c86
--- /dev/null
+++ b/kernel/ksyms_common.c
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ksyms_common.c: A split of kernel/kallsyms.c
+ * Contains a few generic function definations independent of config KALLSYMS.
+ */
+#include <linux/kallsyms.h>
+#include <linux/security.h>
+
+#ifdef CONFIG_KALLSYMS
+static inline int kallsyms_for_perf(void)
+{
+#ifdef CONFIG_PERF_EVENTS
+ extern int sysctl_perf_event_paranoid;
+
+ if (sysctl_perf_event_paranoid <= 1)
+ return 1;
+#endif
+ return 0;
+}
+
+/*
+ * We show kallsyms information even to normal users if we've enabled
+ * kernel profiling and are explicitly not paranoid (so kptr_restrict
+ * is clear, and sysctl_perf_event_paranoid isn't set).
+ *
+ * Otherwise, require CAP_SYSLOG (assuming kptr_restrict isn't set to
+ * block even that).
+ */
+bool kallsyms_show_value(const struct cred *cred)
+{
+ switch (kptr_restrict) {
+ case 0:
+ if (kallsyms_for_perf())
+ return true;
+ fallthrough;
+ case 1:
+ if (security_capable(cred, &init_user_ns, CAP_SYSLOG,
+ CAP_OPT_NOAUDIT) == 0)
+ return true;
+ fallthrough;
+ default:
+ return false;
+ }
+}
+#endif
--
2.17.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH v5 2/2] kallsyms: make kallsyms_show_value() as generic function
[not found] ` <CGME20230608033140epcas5p1a1a04da5a0c78f888afbf54b00519f1e@epcas5p1.samsung.com>
@ 2023-06-08 3:31 ` Maninder Singh
2023-06-08 19:28 ` Luis Chamberlain
0 siblings, 1 reply; 3+ messages in thread
From: Maninder Singh @ 2023-06-08 3:31 UTC (permalink / raw)
To: ast, daniel, john.fastabend, andrii, martin.lau, song, yhs,
kpsingh, sdf, haoluo, jolsa, thunder.leizhen, mcgrof, boqun.feng,
vincenzopalazzodev, ojeda, jgross, brauner, michael.christie,
samitolvanen, glider, peterz, keescook, stephen.s.brennan,
alan.maguire, pmladek
Cc: linux-kernel, bpf, Maninder Singh, Onkarnath
This change makes function kallsyms_show_value() as
generic function without dependency on CONFIG_KALLSYMS.
Now module address will be displayed with lsmod and /proc/modules.
Earlier:
=======
/ # insmod test.ko
/ # lsmod
test 12288 0 - Live 0x0000000000000000 (O) // No Module Load address
/ #
With change:
==========
/ # insmod test.ko
/ # lsmod
test 12288 0 - Live 0xffff800000fc0000 (O) // Module address
/ # cat /proc/modules
test 12288 0 - Live 0xffff800000fc0000 (O)
Co-developed-by: Onkarnath <onkarnath.1@samsung.com>
Signed-off-by: Onkarnath <onkarnath.1@samsung.com>
Signed-off-by: Maninder Singh <maninder1.s@samsung.com>
Reviewed-by: Zhen Lei <thunder.leizhen@huawei.com>
---
include/linux/kallsyms.h | 11 +++--------
kernel/ksyms_common.c | 2 --
2 files changed, 3 insertions(+), 10 deletions(-)
diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h
index 1037f4957caa..c3f075e8f60c 100644
--- a/include/linux/kallsyms.h
+++ b/include/linux/kallsyms.h
@@ -65,6 +65,9 @@ static inline void *dereference_symbol_descriptor(void *ptr)
return ptr;
}
+/* How and when do we show kallsyms values? */
+extern bool kallsyms_show_value(const struct cred *cred);
+
#ifdef CONFIG_KALLSYMS
unsigned long kallsyms_sym_address(int idx);
int kallsyms_on_each_symbol(int (*fn)(void *, const char *, unsigned long),
@@ -94,9 +97,6 @@ extern int sprint_backtrace_build_id(char *buffer, unsigned long address);
int lookup_symbol_name(unsigned long addr, char *symname);
-/* How and when do we show kallsyms values? */
-extern bool kallsyms_show_value(const struct cred *cred);
-
#else /* !CONFIG_KALLSYMS */
static inline unsigned long kallsyms_lookup_name(const char *name)
@@ -154,11 +154,6 @@ static inline int lookup_symbol_name(unsigned long addr, char *symname)
return -ERANGE;
}
-static inline bool kallsyms_show_value(const struct cred *cred)
-{
- return false;
-}
-
static inline int kallsyms_on_each_symbol(int (*fn)(void *, const char *, unsigned long),
void *data)
{
diff --git a/kernel/ksyms_common.c b/kernel/ksyms_common.c
index 3840fa1c9c86..cf1a73cbf2f6 100644
--- a/kernel/ksyms_common.c
+++ b/kernel/ksyms_common.c
@@ -6,7 +6,6 @@
#include <linux/kallsyms.h>
#include <linux/security.h>
-#ifdef CONFIG_KALLSYMS
static inline int kallsyms_for_perf(void)
{
#ifdef CONFIG_PERF_EVENTS
@@ -42,4 +41,3 @@ bool kallsyms_show_value(const struct cred *cred)
return false;
}
}
-#endif
--
2.17.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v5 2/2] kallsyms: make kallsyms_show_value() as generic function
2023-06-08 3:31 ` [PATCH v5 2/2] kallsyms: make kallsyms_show_value() as generic function Maninder Singh
@ 2023-06-08 19:28 ` Luis Chamberlain
0 siblings, 0 replies; 3+ messages in thread
From: Luis Chamberlain @ 2023-06-08 19:28 UTC (permalink / raw)
To: Maninder Singh
Cc: ast, daniel, john.fastabend, andrii, martin.lau, song, yhs,
kpsingh, sdf, haoluo, jolsa, thunder.leizhen, boqun.feng,
vincenzopalazzodev, ojeda, jgross, brauner, michael.christie,
samitolvanen, glider, peterz, keescook, stephen.s.brennan,
alan.maguire, pmladek, linux-kernel, bpf, Onkarnath
On Thu, Jun 08, 2023 at 09:01:19AM +0530, Maninder Singh wrote:
> This change makes function kallsyms_show_value() as
> generic function without dependency on CONFIG_KALLSYMS.
>
> Now module address will be displayed with lsmod and /proc/modules.
>
> Earlier:
> =======
> / # insmod test.ko
> / # lsmod
> test 12288 0 - Live 0x0000000000000000 (O) // No Module Load address
> / #
>
> With change:
> ==========
> / # insmod test.ko
> / # lsmod
> test 12288 0 - Live 0xffff800000fc0000 (O) // Module address
> / # cat /proc/modules
> test 12288 0 - Live 0xffff800000fc0000 (O)
>
> Co-developed-by: Onkarnath <onkarnath.1@samsung.com>
> Signed-off-by: Onkarnath <onkarnath.1@samsung.com>
> Signed-off-by: Maninder Singh <maninder1.s@samsung.com>
> Reviewed-by: Zhen Lei <thunder.leizhen@huawei.com>
Thanks! Pushed to modules-next.
Luis
^ permalink raw reply [flat|nested] 3+ messages in thread
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[not found] <CGME20230608033132epcas5p22208020abf46fc8667086c31b6d7c63d@epcas5p2.samsung.com>
2023-06-08 3:31 ` [PATCH v5 1/2] kallsyms: move kallsyms_show_value() out of kallsyms.c Maninder Singh
[not found] ` <CGME20230608033140epcas5p1a1a04da5a0c78f888afbf54b00519f1e@epcas5p1.samsung.com>
2023-06-08 3:31 ` [PATCH v5 2/2] kallsyms: make kallsyms_show_value() as generic function Maninder Singh
2023-06-08 19:28 ` Luis Chamberlain
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