Re: [PATCH] x86: traps_xx: modify default_do_nmi

Cyrill Gorcunov
2008-07-02T16:13:07Z

[Alexander van Heukelum - Wed, Jul 02, 2008 at 01:32:28AM +0200]
| - local caching of smp_processor_id()
|
| Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
| ---
| arch/x86/kernel/traps_32.c | 12 ++++++++----
| arch/x86/kernel/traps_64.c | 3 ++-
| 2 files changed, 10 insertions(+), 5 deletions(-)
|
| diff --git a/arch/x86/kernel/traps_32.c b/arch/x86/kernel/traps_32.c
| index 68e800f..14fe3cd 100644
| --- a/arch/x86/kernel/traps_32.c
| +++ b/arch/x86/kernel/traps_32.c
| @@ -790,12 +790,16 @@ void notrace __kprobes die_nmi(char *str, struct pt_regs *regs, int do_panic)
| do_exit(SIGSEGV);
| }
|
| -static notrace __kprobes void default_do_nmi(struct pt_regs *regs)
| +static notrace __kprobes void
| +default_do_nmi(struct pt_regs *regs)
| {
| unsigned char reason = 0;
| + int cpu;
| +
| + cpu = smp_processor_id();
|
| - /* Only the BSP gets external NMIs from the system: */
| - if (!smp_processor_id())
| + /* Only the BSP gets external NMIs from the system. */
| + if (!cpu)
| reason = get_nmi_reason();
|
| if (!(reason & 0xc0)) {
| @@ -809,7 +813,7 @@ static notrace __kprobes void default_do_nmi(struct pt_regs *regs)
| */
| if (nmi_watchdog_tick(regs, reason))
| return;
| - if (!do_nmi_callback(regs, smp_processor_id()))
| + if (!do_nmi_callback(regs, cpu))
| unknown_nmi_error(reason, regs);
| #else
| unknown_nmi_error(reason, regs);
| diff --git a/arch/x86/kernel/traps_64.c b/arch/x86/kernel/traps_64.c
| index 677b4e5..2f8d87d 100644
| --- a/arch/x86/kernel/traps_64.c
| +++ b/arch/x86/kernel/traps_64.c
| @@ -832,7 +832,8 @@ unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
|
| /* Runs on IST stack. This code must keep interrupts off all the time.
| Nested NMIs are prevented by the CPU. */
| -asmlinkage notrace __kprobes void default_do_nmi(struct pt_regs *regs)
| +asmlinkage notrace __kprobes void
| +default_do_nmi(struct pt_regs *regs)
| {
| unsigned char reason = 0;
| int cpu;
| --
| 1.5.4.3
|
|

Hi Alexander, good done, thanks! But why did you split default_do_nmi
definition by two lines? I think it would be better to keep them as it
was before, ie by a single line

static notrace __kprobes void default_do_nmi(struct pt_regs *regs)

- Cyrill -