From ce3266c047389443d5f433d605c769e878cbe46e Mon Sep 17 00:00:00 2001 From: "Steven J. Magnani" Date: Tue, 27 Apr 2010 12:37:54 -0500 Subject: microblaze: Add stack unwinder Implement intelligent backtracing by searching for stack frame creation, and emitting only return addresses. Use print_hex_dump() to display the entire binary kernel stack. Limitation: MMU kernels are not currently able to trace beyond a system trap (interrupt, syscall, etc.). It is the intent of this patch to provide infrastructure that can be extended to add this capability later. Changes from V1: * Removed checks in find_frame_creation() that prevented location of the frame creation instruction in heavily optimized code * Various formatting/commenting/file location tweaks per review comments * Dropped Kconfig option to enable STACKTRACE as something logically separate Signed-off-by: Steven J. Magnani --- arch/microblaze/kernel/stacktrace.c | 44 +++++-------------------------------- 1 file changed, 5 insertions(+), 39 deletions(-) (limited to 'arch/microblaze/kernel/stacktrace.c') diff --git a/arch/microblaze/kernel/stacktrace.c b/arch/microblaze/kernel/stacktrace.c index 123692f22647..84bc6686102c 100644 --- a/arch/microblaze/kernel/stacktrace.c +++ b/arch/microblaze/kernel/stacktrace.c @@ -14,52 +14,18 @@ #include #include #include +#include -/* FIXME initial support */ void save_stack_trace(struct stack_trace *trace) { - unsigned long *sp; - unsigned long addr; - asm("addik %0, r1, 0" : "=r" (sp)); - - while (!kstack_end(sp)) { - addr = *sp++; - if (__kernel_text_address(addr)) { - if (trace->skip > 0) - trace->skip--; - else - trace->entries[trace->nr_entries++] = addr; - - if (trace->nr_entries >= trace->max_entries) - break; - } - } + /* Exclude our helper functions from the trace*/ + trace->skip += 2; + microblaze_unwind(NULL, trace); } EXPORT_SYMBOL_GPL(save_stack_trace); void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) { - unsigned int *sp; - unsigned long addr; - - struct thread_info *ti = task_thread_info(tsk); - - if (tsk == current) - asm("addik %0, r1, 0" : "=r" (sp)); - else - sp = (unsigned int *)ti->cpu_context.r1; - - while (!kstack_end(sp)) { - addr = *sp++; - if (__kernel_text_address(addr)) { - if (trace->skip > 0) - trace->skip--; - else - trace->entries[trace->nr_entries++] = addr; - - if (trace->nr_entries >= trace->max_entries) - break; - } - } + microblaze_unwind(tsk, trace); } EXPORT_SYMBOL_GPL(save_stack_trace_tsk); -- cgit v1.2.1