From 0cb91a2293648507886563ccb91979cfc94d6a4b Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Tue, 26 Sep 2006 10:52:28 +0200 Subject: [PATCH] [PATCH] i386: Account spinlocks to the caller during profiling for !FP kernels This ports the algorithm from x86-64 (with improvements) to i386. Previously this only worked for frame pointer enabled kernels. But spinlocks have a very simple stack frame that can be manually analyzed. Do this. Signed-off-by: Andi Kleen --- arch/i386/kernel/time.c | 23 +++++++++++++++++++---- include/asm-i386/ptrace.h | 4 ---- kernel/spinlock.c | 5 +++++ 3 files changed, 24 insertions(+), 8 deletions(-) diff --git a/arch/i386/kernel/time.c b/arch/i386/kernel/time.c index edd00f6cee37..5af802ef00b2 100644 --- a/arch/i386/kernel/time.c +++ b/arch/i386/kernel/time.c @@ -130,18 +130,33 @@ static int set_rtc_mmss(unsigned long nowtime) int timer_ack; -#if defined(CONFIG_SMP) && defined(CONFIG_FRAME_POINTER) unsigned long profile_pc(struct pt_regs *regs) { unsigned long pc = instruction_pointer(regs); - if (!user_mode_vm(regs) && in_lock_functions(pc)) +#ifdef CONFIG_SMP + if (!user_mode_vm(regs) && in_lock_functions(pc)) { +#ifdef CONFIG_FRAME_POINTER return *(unsigned long *)(regs->ebp + 4); - +#else + unsigned long *sp; + if ((regs->xcs & 3) == 0) + sp = (unsigned long *)®s->esp; + else + sp = (unsigned long *)regs->esp; + /* Return address is either directly at stack pointer + or above a saved eflags. Eflags has bits 22-31 zero, + kernel addresses don't. */ + if (sp[0] >> 22) + return sp[0]; + if (sp[1] >> 22) + return sp[1]; +#endif + } +#endif return pc; } EXPORT_SYMBOL(profile_pc); -#endif /* * This is the same as the above, except we _also_ save the current diff --git a/include/asm-i386/ptrace.h b/include/asm-i386/ptrace.h index f324c53b6f9a..30a442ec2059 100644 --- a/include/asm-i386/ptrace.h +++ b/include/asm-i386/ptrace.h @@ -80,11 +80,7 @@ static inline int user_mode_vm(struct pt_regs *regs) return ((regs->xcs & 3) | (regs->eflags & VM_MASK)) != 0; } #define instruction_pointer(regs) ((regs)->eip) -#if defined(CONFIG_SMP) && defined(CONFIG_FRAME_POINTER) extern unsigned long profile_pc(struct pt_regs *regs); -#else -#define profile_pc(regs) instruction_pointer(regs) -#endif #endif /* __KERNEL__ */ #endif diff --git a/kernel/spinlock.c b/kernel/spinlock.c index fb524b009eef..9644a41e0bef 100644 --- a/kernel/spinlock.c +++ b/kernel/spinlock.c @@ -7,6 +7,11 @@ * * This file contains the spinlock/rwlock implementations for the * SMP and the DEBUG_SPINLOCK cases. (UP-nondebug inlines them) + * + * Note that some architectures have special knowledge about the + * stack frames of these functions in their profile_pc. If you + * change anything significant here that could change the stack + * frame contact the architecture maintainers. */ #include -- 2.20.1