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| author | Masami Hiramatsu <mhiramat@redhat.com> | 2009-03-06 10:37:22 -0500 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-03-06 16:49:00 +0100 |
| commit | 3945dab45aa8c89014893bfa8eb1e1661a409cef (patch) | |
| tree | dff11f176f0027d8958c7176524e7a64e8711f30 | |
| parent | 4460fdad85becd569f11501ad5b91814814335ff (diff) | |
| download | kernel-crypto-3945dab45aa8c89014893bfa8eb1e1661a409cef.tar.gz kernel-crypto-3945dab45aa8c89014893bfa8eb1e1661a409cef.tar.xz kernel-crypto-3945dab45aa8c89014893bfa8eb1e1661a409cef.zip | |
tracing, Text Edit Lock - SMP alternatives support
Use the mutual exclusion provided by the text edit lock in alternatives code.
Since alternative_smp_* will be called from module init code, etc,
we'd better protect it from other subsystems.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
LKML-Reference: <49B14332.9030109@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | arch/x86/kernel/alternative.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 4c80f155743..092a7b8be68 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -5,6 +5,7 @@ #include <linux/kprobes.h> #include <linux/mm.h> #include <linux/vmalloc.h> +#include <linux/memory.h> #include <asm/alternative.h> #include <asm/sections.h> #include <asm/pgtable.h> @@ -226,6 +227,7 @@ static void alternatives_smp_lock(u8 **start, u8 **end, u8 *text, u8 *text_end) { u8 **ptr; + mutex_lock(&text_mutex); for (ptr = start; ptr < end; ptr++) { if (*ptr < text) continue; @@ -234,6 +236,7 @@ static void alternatives_smp_lock(u8 **start, u8 **end, u8 *text, u8 *text_end) /* turn DS segment override prefix into lock prefix */ text_poke(*ptr, ((unsigned char []){0xf0}), 1); }; + mutex_unlock(&text_mutex); } static void alternatives_smp_unlock(u8 **start, u8 **end, u8 *text, u8 *text_end) @@ -243,6 +246,7 @@ static void alternatives_smp_unlock(u8 **start, u8 **end, u8 *text, u8 *text_end if (noreplace_smp) return; + mutex_lock(&text_mutex); for (ptr = start; ptr < end; ptr++) { if (*ptr < text) continue; @@ -251,6 +255,7 @@ static void alternatives_smp_unlock(u8 **start, u8 **end, u8 *text, u8 *text_end /* turn lock prefix into DS segment override prefix */ text_poke(*ptr, ((unsigned char []){0x3E}), 1); }; + mutex_unlock(&text_mutex); } struct smp_alt_module { |