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authorJiri Kosina <jkosina@suse.cz>2013-07-12 09:22:09 (GMT)
committerH. Peter Anvin <hpa@linux.intel.com>2013-07-17 00:55:37 (GMT)
commit51b2c07b22261f19188d9a9071943d60a067481c (patch)
treec4c220205050ed11403ed8610fd557d44296bbb1 /arch/x86/kernel/jump_label.c
parentfd4363fff3d96795d3feb1b3fb48ce590f186bdd (diff)
x86: Make jump_label use int3-based patching
Make jump labels use text_poke_bp() for text patching instead of text_poke_smp(), avoiding the need for stop_machine(). Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Link: http://lkml.kernel.org/r/alpine.LNX.2.00.1307121120250.29788@pobox.suse.cz Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'arch/x86/kernel/jump_label.c')
-rw-r--r--arch/x86/kernel/jump_label.c16
1 files changed, 14 insertions, 2 deletions
diff --git a/arch/x86/kernel/jump_label.c b/arch/x86/kernel/jump_label.c
index 2889b3d..460f5d9 100644
--- a/arch/x86/kernel/jump_label.c
+++ b/arch/x86/kernel/jump_label.c
@@ -37,7 +37,19 @@ static void __jump_label_transform(struct jump_entry *entry,
} else
memcpy(&code, ideal_nops[NOP_ATOMIC5], JUMP_LABEL_NOP_SIZE);
- (*poker)((void *)entry->code, &code, JUMP_LABEL_NOP_SIZE);
+ /*
+ * Make text_poke_bp() a default fallback poker.
+ *
+ * At the time the change is being done, just ignore whether we
+ * are doing nop -> jump or jump -> nop transition, and assume
+ * always nop being the 'currently valid' instruction
+ *
+ */
+ if (poker)
+ (*poker)((void *)entry->code, &code, JUMP_LABEL_NOP_SIZE);
+ else
+ text_poke_bp((void *)entry->code, &code, JUMP_LABEL_NOP_SIZE,
+ (void *)entry->code + JUMP_LABEL_NOP_SIZE);
}
void arch_jump_label_transform(struct jump_entry *entry,
@@ -45,7 +57,7 @@ void arch_jump_label_transform(struct jump_entry *entry,
{
get_online_cpus();
mutex_lock(&text_mutex);
- __jump_label_transform(entry, type, text_poke_smp);
+ __jump_label_transform(entry, type, NULL);
mutex_unlock(&text_mutex);
put_online_cpus();
}

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