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| author | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2020-10-28 17:15:27 -0400 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2020-11-13 12:15:28 -0500 |
| commit | 2860cd8a235375df3c8ec8039d9fe5eb2f658b86 (patch) | |
| tree | fdc9022ea4057f4d410d7b907b158d7cbb8787e8 /arch/x86/include | |
| parent | 02a474ca266a47ea8f4d5a11f4ffa120f83730ad (diff) | |
| download | linux-2860cd8a235375df3c8ec8039d9fe5eb2f658b86.tar.gz linux-2860cd8a235375df3c8ec8039d9fe5eb2f658b86.tar.bz2 linux-2860cd8a235375df3c8ec8039d9fe5eb2f658b86.zip | |
livepatch: Use the default ftrace_ops instead of REGS when ARGS is available
When CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS is available, the ftrace call
will be able to set the ip of the calling function. This will improve the
performance of live kernel patching where it does not need all the regs to
be stored just to change the instruction pointer.
If all archs that support live kernel patching also support
HAVE_DYNAMIC_FTRACE_WITH_ARGS, then the architecture specific function
klp_arch_set_pc() could be made generic.
It is possible that an arch can support HAVE_DYNAMIC_FTRACE_WITH_ARGS but
not HAVE_DYNAMIC_FTRACE_WITH_REGS and then have access to live patching.
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: live-patching@vger.kernel.org
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'arch/x86/include')
| -rw-r--r-- | arch/x86/include/asm/ftrace.h | 3 | ||||
| -rw-r--r-- | arch/x86/include/asm/livepatch.h | 4 |
2 files changed, 5 insertions, 2 deletions
diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h index e00fe88146e0..9f3130f40807 100644 --- a/arch/x86/include/asm/ftrace.h +++ b/arch/x86/include/asm/ftrace.h @@ -54,6 +54,9 @@ arch_ftrace_get_regs(struct ftrace_regs *fregs) return NULL; return &fregs->regs; } + +#define ftrace_instruction_pointer_set(fregs, _ip) \ + do { (fregs)->regs.ip = (_ip); } while (0) #endif #ifdef CONFIG_DYNAMIC_FTRACE diff --git a/arch/x86/include/asm/livepatch.h b/arch/x86/include/asm/livepatch.h index 1fde1ab6559e..7c5cc6660e4b 100644 --- a/arch/x86/include/asm/livepatch.h +++ b/arch/x86/include/asm/livepatch.h @@ -12,9 +12,9 @@ #include <asm/setup.h> #include <linux/ftrace.h> -static inline void klp_arch_set_pc(struct pt_regs *regs, unsigned long ip) +static inline void klp_arch_set_pc(struct ftrace_regs *fregs, unsigned long ip) { - regs->ip = ip; + ftrace_instruction_pointer_set(fregs, ip); } #endif /* _ASM_X86_LIVEPATCH_H */ |