From: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
To: Tony Luck <tony.luck@intel.com>,
Fenghua Yu <fenghua.yu@intel.com>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>,
"James E . J . Bottomley" <jejb@parisc-linux.org>,
Helge Deller <deller@gmx.de>
Cc: Petr Mladek <pmladek@suse.com>,
Steven Rostedt <rostedt@goodmis.org>,
Andrew Morton <akpm@linux-foundation.org>,
Jessica Yu <jeyu@kernel.org>, Alexei Starovoitov <ast@kernel.org>,
linux-ia64@vger.kernel.org, linux-parisc@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Subject: [PATCH 3/5] powerpc64: Add .opd based function descriptor dereference
Date: Sat, 16 Sep 2017 12:53:45 +0900 [thread overview]
Message-ID: <20170916035347.19705-4-sergey.senozhatsky@gmail.com> (raw)
In-Reply-To: <20170916035347.19705-1-sergey.senozhatsky@gmail.com>
We are moving towards separate kernel and module function descriptor
dereference callbacks. This patch enables it for powerpc64.
For pointers that belong to the kernel
- Added __start_opd and __end_opd pointers, to track the kernel
.opd section address range;
- Added dereference_kernel_function_descriptor(). Now we
will dereference only function pointers that are within
[__start_opd, __end_opd];
For pointers that belong to a module
- Added dereference_module_function_descriptor() to handle module
function descriptor dereference. Now we will dereference only
pointers that are within [module->opd.start, module->opd.end].
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
---
arch/powerpc/include/asm/module.h | 3 +++
arch/powerpc/include/asm/sections.h | 13 +++++++++++++
arch/powerpc/kernel/module_64.c | 16 ++++++++++++++++
arch/powerpc/kernel/vmlinux.lds.S | 2 ++
4 files changed, 34 insertions(+)
diff --git a/arch/powerpc/include/asm/module.h b/arch/powerpc/include/asm/module.h
index 6c0132c7212f..7e28442827f1 100644
--- a/arch/powerpc/include/asm/module.h
+++ b/arch/powerpc/include/asm/module.h
@@ -45,6 +45,9 @@ struct mod_arch_specific {
unsigned long tramp;
#endif
+ /* For module function descriptor dereference */
+ unsigned long start_opd;
+ unsigned long end_opd;
#else /* powerpc64 */
/* Indices of PLT sections within module. */
unsigned int core_plt_section;
diff --git a/arch/powerpc/include/asm/sections.h b/arch/powerpc/include/asm/sections.h
index 7902d6358854..7cc4db86952b 100644
--- a/arch/powerpc/include/asm/sections.h
+++ b/arch/powerpc/include/asm/sections.h
@@ -16,6 +16,9 @@ extern char __end_interrupts[];
extern char __prom_init_toc_start[];
extern char __prom_init_toc_end[];
+extern char __start_opd[];
+extern char __end_opd[];
+
static inline int in_kernel_text(unsigned long addr)
{
if (addr >= (unsigned long)_stext && addr < (unsigned long)__init_end)
@@ -66,6 +69,8 @@ static inline int overlaps_kvm_tmp(unsigned long start, unsigned long end)
#ifdef PPC64_ELF_ABI_v1
#undef dereference_function_descriptor
+#undef dereference_kernel_function_descriptor
+
static inline void *dereference_function_descriptor(void *ptr)
{
struct ppc64_opd_entry *desc = ptr;
@@ -75,6 +80,14 @@ static inline void *dereference_function_descriptor(void *ptr)
ptr = p;
return ptr;
}
+
+static inline void *dereference_kernel_function_descriptor(void *ptr)
+{
+ if (ptr < (void *)__start_opd || (void *)__end_opd < ptr)
+ return ptr;
+
+ return dereference_function_descriptor(ptr);
+}
#endif /* PPC64_ELF_ABI_v1 */
#endif
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index 0b0f89685b67..52aa5d668364 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -344,6 +344,11 @@ int module_frob_arch_sections(Elf64_Ehdr *hdr,
else if (strcmp(secstrings+sechdrs[i].sh_name,"__versions")==0)
dedotify_versions((void *)hdr + sechdrs[i].sh_offset,
sechdrs[i].sh_size);
+ else if (strcmp(secstrings + sechdrs[i].sh_name, ".opd")==0) {
+ me->arch.start_opd = sechdrs[i].sh_offset;
+ me->arch.end_opd = me->arch.start_opd +
+ sechdrs[i].sh_size;
+ }
/* We don't handle .init for the moment: rename to _init */
while ((p = strstr(secstrings + sechdrs[i].sh_name, ".init")))
@@ -712,6 +717,17 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
return 0;
}
+#ifdef PPC64_ELF_ABI_v1
+unsigned long dereference_module_function_descriptor(struct module *mod,
+ unsigned long addr)
+{
+ if (addr < mod->arch.start_opd || mod->arch.end_opd < addr)
+ return addr;
+
+ return dereference_function_descriptor(addr);
+}
+#endif /* PPC64_ELF_ABI_v1 */
+
#ifdef CONFIG_DYNAMIC_FTRACE
#ifdef CC_USING_MPROFILE_KERNEL
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 882628fa6987..70e10251e083 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -277,7 +277,9 @@ SECTIONS
}
.opd : AT(ADDR(.opd) - LOAD_OFFSET) {
+ __start_opd = .;
*(.opd)
+ __end_opd = .;
}
. = ALIGN(256);
--
2.14.1
next prev parent reply other threads:[~2017-09-16 3:59 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-16 3:53 [PATCH 0/5] [RFC] printk/ia64/ppc64/parisc64: let's deprecate %pF/%pf printk specifiers Sergey Senozhatsky
2017-09-16 3:53 ` [PATCH 1/5] sections: split dereference_function_descriptor() Sergey Senozhatsky
2017-09-16 3:53 ` [PATCH 2/5] ia64: Add .opd based function descriptor dereference Sergey Senozhatsky
2017-09-16 3:53 ` Sergey Senozhatsky [this message]
2017-09-16 9:43 ` [PATCH 3/5] powerpc64: " Naveen N. Rao
2017-09-16 11:25 ` Sergey Senozhatsky
2017-09-19 10:22 ` Michael Ellerman
2017-09-19 10:31 ` Sergey Senozhatsky
2017-09-20 1:51 ` Michael Ellerman
2017-09-20 6:10 ` Sergey Senozhatsky
2017-09-16 3:53 ` [PATCH 4/5] parisc64: " Sergey Senozhatsky
2017-09-16 3:53 ` [PATCH 5/5] symbol lookup: use new kernel and module dereference functions Sergey Senozhatsky
2017-09-18 17:44 ` [PATCH 0/5] [RFC] printk/ia64/ppc64/parisc64: let's deprecate %pF/%pf printk specifiers Luck, Tony
2017-09-18 18:39 ` Helge Deller
2017-09-19 2:05 ` Sergey Senozhatsky
2017-09-19 13:38 ` David Laight
2017-09-19 20:07 ` Helge Deller
2017-09-20 8:41 ` David Laight
2017-09-20 10:20 ` Helge Deller
2017-09-20 16:31 ` Sergey Senozhatsky
2017-09-19 14:07 ` Helge Deller
2017-09-19 20:03 ` Helge Deller
2017-09-20 0:47 ` Sergey Senozhatsky
2017-09-19 2:08 ` Sergey Senozhatsky
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