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Subject[-mm patch] enforce noreplace-smp in alternative_instructions()
On Wed, Aug 22, 2007 at 02:06:48AM -0700, Andrew Morton wrote:
>
> ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.23-rc3/2.6.23-rc3-mm1/
>
Hi Jeremy,

arch/i386/kernel/alternative.c:alternative_instructions() doesn't
check for noreplace-smp before setting capability bits and freeing the
__smp_locks section.

Every call to alternatives_smp_unlock() checks for noreplace-smp
beforehand, so remove the check from there.

Boot tested on i386 with UP+noreplace-smp (lguest) and SMP (real hardware)

Regards,
Frederik

Signed-off-by: Frederik Deweerdt <frederik.deweerdt@gmail.com>

diff --git a/arch/i386/kernel/alternative.c b/arch/i386/kernel/alternative.c
index 9f4ac8b..7c5af80 100644
--- a/arch/i386/kernel/alternative.c
+++ b/arch/i386/kernel/alternative.c
@@ -221,9 +221,6 @@ static void alternatives_smp_unlock(u8 **start, u8 **end, u8 *text, u8 *text_end
u8 **ptr;
char insn[1];

- if (noreplace_smp)
- return;
-
add_nops(insn, 1);
for (ptr = start; ptr < end; ptr++) {
if (*ptr < text)
@@ -406,7 +403,7 @@ void __init alternative_instructions(void)
#endif

#ifdef CONFIG_SMP
- if (smp_alt_once) {
+ if (smp_alt_once && !noreplace_smp) {
if (1 == num_possible_cpus()) {
printk(KERN_INFO "SMP alternatives: switching to UP code\n");
set_bit(X86_FEATURE_UP, boot_cpu_data.x86_capability);
-
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