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| author | Jason Baron <jbaron@redhat.com> | 2010-09-17 17:09:00 +0200 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2010-09-22 22:29:41 +0200 |
| commit | bf5438fca2950b03c21ad868090cc1a8fcd49536 (patch) | |
| tree | 9fc5693763263704de8d8ba1c37a84172dbe5eb7 /arch/x86/kernel/alternative.c | |
| parent | jump label: Make text_poke_early() globally visible (diff) | |
| download | linux-bf5438fca2950b03c21ad868090cc1a8fcd49536.tar.xz linux-bf5438fca2950b03c21ad868090cc1a8fcd49536.zip | |
jump label: Base patch for jump label
base patch to implement 'jump labeling'. Based on a new 'asm goto' inline
assembly gcc mechanism, we can now branch to labels from an 'asm goto'
statment. This allows us to create a 'no-op' fastpath, which can subsequently
be patched with a jump to the slowpath code. This is useful for code which
might be rarely used, but which we'd like to be able to call, if needed.
Tracepoints are the current usecase that these are being implemented for.
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <ee8b3595967989fdaf84e698dc7447d315ce972a.1284733808.git.jbaron@redhat.com>
[ cleaned up some formating ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'arch/x86/kernel/alternative.c')
| -rw-r--r-- | arch/x86/kernel/alternative.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 083bd010d92c..cb0e6d385f6d 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -641,7 +641,7 @@ void *__kprobes text_poke_smp(void *addr, const void *opcode, size_t len) return addr; } -#if defined(CONFIG_DYNAMIC_FTRACE) +#if defined(CONFIG_DYNAMIC_FTRACE) || defined(HAVE_JUMP_LABEL) unsigned char ideal_nop5[IDEAL_NOP_SIZE_5]; |