Gitweb:
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=9ce883becb83190061369940de9c415595836c9b
Commit: 9ce883becb83190061369940de9c415595836c9b
Parent: cf6387daf8858bdcb3e123034ca422e8979d73f1
Author: Andi Kleen <[EMAIL PROTECTED]>
AuthorDate: Tue Apr 24 13:05:37 2007 +0200
Committer: Andi Kleen <[EMAIL PROTECTED]>
CommitDate: Tue Apr 24 13:05:37 2007 +0200
[PATCH] x86: Remove noreplacement option
noreplacement is dangerous on modern systems because it will not replace the
context switch FNSAVE with SSE aware FXSAVE. But other places in the kernel
still assume
SSE and do FXSAVE and the CPU will then access FXSAVE information with
FNSAVE and cause corruption.
Easiest way to avoid this is to remove the option. It was mostly for
paranoia
reasons anyways and alternative()s have been stable for some time.
Thanks to Jeremy F. for reporting and helping debug it.
Signed-off-by: Andi Kleen <[EMAIL PROTECTED]>
---
Documentation/x86_64/boot-options.txt | 4 ----
arch/i386/kernel/alternative.c | 21 ++-------------------
2 files changed, 2 insertions(+), 23 deletions(-)
diff --git a/Documentation/x86_64/boot-options.txt
b/Documentation/x86_64/boot-options.txt
index 625a21d..85f51e5 100644
--- a/Documentation/x86_64/boot-options.txt
+++ b/Documentation/x86_64/boot-options.txt
@@ -293,7 +293,3 @@ Debugging
stuck (default)
Miscellaneous
-
- noreplacement Don't replace instructions with more appropriate ones
- for the CPU. This may be useful on asymmetric MP systems
- where some CPUs have less capabilities than others.
diff --git a/arch/i386/kernel/alternative.c b/arch/i386/kernel/alternative.c
index 9eca21b..426f59b 100644
--- a/arch/i386/kernel/alternative.c
+++ b/arch/i386/kernel/alternative.c
@@ -5,15 +5,9 @@
#include <asm/alternative.h>
#include <asm/sections.h>
-static int no_replacement = 0;
static int smp_alt_once = 0;
static int debug_alternative = 0;
-static int __init noreplacement_setup(char *s)
-{
- no_replacement = 1;
- return 1;
-}
static int __init bootonly(char *str)
{
smp_alt_once = 1;
@@ -25,7 +19,6 @@ static int __init debug_alt(char *str)
return 1;
}
-__setup("noreplacement", noreplacement_setup);
__setup("smp-alt-boot", bootonly);
__setup("debug-alternative", debug_alt);
@@ -252,9 +245,6 @@ void alternatives_smp_module_add(struct module *mod, char
*name,
struct smp_alt_module *smp;
unsigned long flags;
- if (no_replacement)
- return;
-
if (smp_alt_once) {
if (boot_cpu_has(X86_FEATURE_UP))
alternatives_smp_unlock(locks, locks_end,
@@ -289,7 +279,7 @@ void alternatives_smp_module_del(struct module *mod)
struct smp_alt_module *item;
unsigned long flags;
- if (no_replacement || smp_alt_once)
+ if (smp_alt_once)
return;
spin_lock_irqsave(&smp_alt, flags);
@@ -320,7 +310,7 @@ void alternatives_smp_switch(int smp)
return;
#endif
- if (no_replacement || smp_alt_once)
+ if (smp_alt_once)
return;
BUG_ON(!smp && (num_online_cpus() > 1));
@@ -386,13 +376,6 @@ extern struct paravirt_patch __start_parainstructions[],
void __init alternative_instructions(void)
{
unsigned long flags;
- if (no_replacement) {
- printk(KERN_INFO "(SMP-)alternatives turned off\n");
- free_init_pages("SMP alternatives",
- (unsigned long)__smp_alt_begin,
- (unsigned long)__smp_alt_end);
- return;
- }
local_irq_save(flags);
apply_alternatives(__alt_instructions, __alt_instructions_end);
-
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