diff options
author | Ingo Molnar <mingo@elte.hu> | 2006-07-03 00:24:39 -0700 |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-07-03 15:27:02 -0700 |
commit | 4a7c7197817e7180f56110334d961f4aa6ac69cb (patch) | |
tree | ae4fa9c4a54b21af812fdc4c3a75165e30a84cce /arch/i386/kernel/stacktrace.c | |
parent | cbbd1fa72d22896332301ca7e6b7164284be105c (diff) | |
download | op-kernel-dev-4a7c7197817e7180f56110334d961f4aa6ac69cb.zip op-kernel-dev-4a7c7197817e7180f56110334d961f4aa6ac69cb.tar.gz |
[PATCH] lockdep: stacktrace subsystem, i386 support
Framework to generate and save stacktraces quickly, without printing anything
to the console. i386 support.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/i386/kernel/stacktrace.c')
-rw-r--r-- | arch/i386/kernel/stacktrace.c | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/arch/i386/kernel/stacktrace.c b/arch/i386/kernel/stacktrace.c new file mode 100644 index 0000000..e62a037 --- /dev/null +++ b/arch/i386/kernel/stacktrace.c @@ -0,0 +1,98 @@ +/* + * arch/i386/kernel/stacktrace.c + * + * Stack trace management functions + * + * Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> + */ +#include <linux/sched.h> +#include <linux/stacktrace.h> + +static inline int valid_stack_ptr(struct thread_info *tinfo, void *p) +{ + return p > (void *)tinfo && + p < (void *)tinfo + THREAD_SIZE - 3; +} + +/* + * Save stack-backtrace addresses into a stack_trace buffer: + */ +static inline unsigned long +save_context_stack(struct stack_trace *trace, unsigned int skip, + struct thread_info *tinfo, unsigned long *stack, + unsigned long ebp) +{ + unsigned long addr; + +#ifdef CONFIG_FRAME_POINTER + while (valid_stack_ptr(tinfo, (void *)ebp)) { + addr = *(unsigned long *)(ebp + 4); + if (!skip) + trace->entries[trace->nr_entries++] = addr; + else + skip--; + if (trace->nr_entries >= trace->max_entries) + break; + /* + * break out of recursive entries (such as + * end_of_stack_stop_unwind_function): + */ + if (ebp == *(unsigned long *)ebp) + break; + + ebp = *(unsigned long *)ebp; + } +#else + while (valid_stack_ptr(tinfo, stack)) { + addr = *stack++; + if (__kernel_text_address(addr)) { + if (!skip) + trace->entries[trace->nr_entries++] = addr; + else + skip--; + if (trace->nr_entries >= trace->max_entries) + break; + } + } +#endif + + return ebp; +} + +/* + * Save stack-backtrace addresses into a stack_trace buffer. + * If all_contexts is set, all contexts (hardirq, softirq and process) + * are saved. If not set then only the current context is saved. + */ +void save_stack_trace(struct stack_trace *trace, + struct task_struct *task, int all_contexts, + unsigned int skip) +{ + unsigned long ebp; + unsigned long *stack = &ebp; + + WARN_ON(trace->nr_entries || !trace->max_entries); + + if (!task || task == current) { + /* Grab ebp right from our regs: */ + asm ("movl %%ebp, %0" : "=r" (ebp)); + } else { + /* ebp is the last reg pushed by switch_to(): */ + ebp = *(unsigned long *) task->thread.esp; + } + + while (1) { + struct thread_info *context = (struct thread_info *) + ((unsigned long)stack & (~(THREAD_SIZE - 1))); + + ebp = save_context_stack(trace, skip, context, stack, ebp); + stack = (unsigned long *)context->previous_esp; + if (!all_contexts || !stack || + trace->nr_entries >= trace->max_entries) + break; + trace->entries[trace->nr_entries++] = ULONG_MAX; + if (trace->nr_entries >= trace->max_entries) + break; + } +} + |