From: Russell King Date: Sat, 28 Apr 2007 08:59:37 +0000 (+0100) Subject: [ARM] Add stacktrace support and make oprofile use it X-Git-Tag: v2.6.22-rc1~1009^2~1^6~4 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f16fb1ecc5a1cb2f7cc595179d1fe55e711e599f;p=linux-2.6 [ARM] Add stacktrace support and make oprofile use it Add support for stacktrace. Use the new stacktrace code with oprofile instead of it's version; there's no point having multiple versions of stacktracing in the kernel. Signed-off-by: Russell King --- diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index e7baca29f3..e25a197af6 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -67,6 +67,14 @@ config GENERIC_HARDIRQS bool default y +config STACKTRACE_SUPPORT + bool + default y + +config LOCKDEP_SUPPORT + bool + default y + config TRACE_IRQFLAGS_SUPPORT bool default y diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index bb28087bf8..593b56509f 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -7,8 +7,8 @@ AFLAGS_head.o := -DTEXT_OFFSET=$(TEXT_OFFSET) # Object file lists. obj-y := compat.o entry-armv.o entry-common.o irq.o \ - process.o ptrace.o semaphore.o setup.o signal.o sys_arm.o \ - time.o traps.o + process.o ptrace.o semaphore.o setup.o signal.o \ + sys_arm.o stacktrace.o time.o traps.o obj-$(CONFIG_ISA_DMA_API) += dma.o obj-$(CONFIG_ARCH_ACORN) += ecard.o diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c new file mode 100644 index 0000000000..77ef35efaa --- /dev/null +++ b/arch/arm/kernel/stacktrace.c @@ -0,0 +1,73 @@ +#include +#include + +#include "stacktrace.h" + +int walk_stackframe(unsigned long fp, unsigned long low, unsigned long high, + int (*fn)(struct stackframe *, void *), void *data) +{ + struct stackframe *frame; + + do { + /* + * Check current frame pointer is within bounds + */ + if ((fp - 12) < low || fp + 4 >= high) + break; + + frame = (struct stackframe *)(fp - 12); + + if (fn(frame, data)) + break; + + /* + * Update the low bound - the next frame must always + * be at a higher address than the current frame. + */ + low = fp + 4; + fp = frame->fp; + } while (fp); + + return 0; +} + +#ifdef CONFIG_STACKTRACE +struct stack_trace_data { + struct stack_trace *trace; + unsigned int skip; +}; + +static int save_trace(struct stackframe *frame, void *d) +{ + struct stack_trace_data *data = d; + struct stack_trace *trace = data->trace; + + if (data->skip) { + data->skip--; + return 0; + } + + trace->entries[trace->nr_entries++] = frame->lr; + + return trace->nr_entries >= trace->max_entries; +} + +void save_stack_trace(struct stack_trace *trace, struct task_struct *task) +{ + struct stack_trace_data data; + unsigned long fp, base; + + data.trace = trace; + data.skip = trace->skip; + + if (task) { + base = (unsigned long)task_stack_page(task); + fp = 0; /* FIXME */ + } else { + base = (unsigned long)task_stack_page(current); + asm("mov %0, fp" : "=r" (fp)); + } + + walk_stackframe(fp, base, base + THREAD_SIZE, save_trace, &data); +} +#endif diff --git a/arch/arm/kernel/stacktrace.h b/arch/arm/kernel/stacktrace.h new file mode 100644 index 0000000000..e9fd20cb56 --- /dev/null +++ b/arch/arm/kernel/stacktrace.h @@ -0,0 +1,9 @@ +struct stackframe { + unsigned long fp; + unsigned long sp; + unsigned long lr; + unsigned long pc; +}; + +int walk_stackframe(unsigned long fp, unsigned long low, unsigned long high, + int (*fn)(struct stackframe *, void *), void *data); diff --git a/arch/arm/oprofile/backtrace.c b/arch/arm/oprofile/backtrace.c index 7c22c12618..f5ebf30151 100644 --- a/arch/arm/oprofile/backtrace.c +++ b/arch/arm/oprofile/backtrace.c @@ -19,6 +19,19 @@ #include #include +#include "../kernel/stacktrace.h" + +static int report_trace(struct stackframe *frame, void *d) +{ + unsigned int *depth = d; + + if (*depth) { + oprofile_add_trace(frame->lr); + (*depth)--; + } + + return *depth == 0; +} /* * The registers we're interested in are at the end of the variable @@ -32,21 +45,6 @@ struct frame_tail { unsigned long lr; } __attribute__((packed)); - -#ifdef CONFIG_FRAME_POINTER -static struct frame_tail* kernel_backtrace(struct frame_tail *tail) -{ - oprofile_add_trace(tail->lr); - - /* frame pointers should strictly progress back up the stack - * (towards higher addresses) */ - if (tail >= tail->fp) - return NULL; - - return tail->fp-1; -} -#endif - static struct frame_tail* user_backtrace(struct frame_tail *tail) { struct frame_tail buftail[2]; @@ -67,47 +65,14 @@ static struct frame_tail* user_backtrace(struct frame_tail *tail) return buftail[0].fp-1; } -/* - * | | /\ Higher addresses - * | | - * --------------- stack base (address of current_thread_info) - * | thread info | - * . . - * | stack | - * --------------- saved regs->ARM_fp value if valid (frame_tail address) - * . . - * --------------- struct pt_regs stored on stack (struct pt_regs *) - * | | - * . . - * | | - * --------------- %esp - * | | - * | | \/ Lower addresses - * - * Thus, &pt_regs <-> stack base restricts the valid(ish) fp values - */ -static int valid_kernel_stack(struct frame_tail *tail, struct pt_regs *regs) -{ - unsigned long tailaddr = (unsigned long)tail; - unsigned long stack = (unsigned long)regs; - unsigned long stack_base = (stack & ~(THREAD_SIZE - 1)) + THREAD_SIZE; - - return (tailaddr > stack) && (tailaddr < stack_base); -} - void arm_backtrace(struct pt_regs * const regs, unsigned int depth) { - struct frame_tail *tail; - - tail = ((struct frame_tail *) regs->ARM_fp) - 1; + struct frame_tail *tail = ((struct frame_tail *) regs->ARM_fp) - 1; if (!user_mode(regs)) { - -#ifdef CONFIG_FRAME_POINTER - while (depth-- && tail && valid_kernel_stack(tail, regs)) { - tail = kernel_backtrace(tail); - } -#endif + unsigned long base = ((unsigned long)regs) & ~(THREAD_SIZE - 1); + walk_stackframe(regs->ARM_fp, base, base + THREAD_SIZE, + report_trace, &depth); return; }