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authorMasami Hiramatsu <mhiramat@redhat.com>2010-03-04 06:38:50 +0300
committerIngo Molnar <mingo@elte.hu>2010-03-04 13:39:21 +0300
commite5a11016643d1ab7172193591506d33a844734cc (patch)
tree45e9c865c1e25c19142cb395e98ef13dd6d6f145
parent32cb0dd50672056e510ccab442dc9c3a03be649e (diff)
downloadlinux-e5a11016643d1ab7172193591506d33a844734cc.tar.xz
x86: Issue at least one memory barrier in stop_machine_text_poke()
Fix stop_machine_text_poke() to issue smp_mb() before exiting waiting loop, and use cpu_relax() for waiting. Changes in v2: - Don't use ACCESS_ONCE(). Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: systemtap <systemtap@sources.redhat.com> Cc: DLE <dle-develop@lists.sourceforge.net> Cc: Jason Baron <jbaron@redhat.com> LKML-Reference: <20100304033850.3819.74590.stgit@localhost6.localdomain6> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--arch/x86/kernel/alternative.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index c41f13c15e8f..e0b877099470 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -595,8 +595,8 @@ static int __kprobes stop_machine_text_poke(void *data)
wrote_text = 1;
} else {
while (!wrote_text)
- smp_rmb();
- sync_core();
+ cpu_relax();
+ smp_mb(); /* Load wrote_text before following execution */
}
flush_icache_range((unsigned long)tpp->addr,