diff options
| -rw-r--r-- | arch/x86/oprofile/backtrace.c | 104 |
1 files changed, 38 insertions, 66 deletions
diff --git a/arch/x86/oprofile/backtrace.c b/arch/x86/oprofile/backtrace.c index c049ce4..dc59a80 100644 --- a/arch/x86/oprofile/backtrace.c +++ b/arch/x86/oprofile/backtrace.c @@ -13,25 +13,45 @@ #include <linux/mm.h> #include <asm/ptrace.h> #include <asm/uaccess.h> +#include <asm/stacktrace.h> -struct frame_head { - struct frame_head * ebp; - unsigned long ret; -} __attribute__((packed)); +static void backtrace_warning_symbol(void *data, char *msg, + unsigned long symbol) +{ + /* Ignore warnings */ +} -static struct frame_head * -dump_kernel_backtrace(struct frame_head * head) +static void backtrace_warning(void *data, char *msg) { - oprofile_add_trace(head->ret); + /* Ignore warnings */ +} - /* frame pointers should strictly progress back up the stack - * (towards higher addresses) */ - if (head >= head->ebp) - return NULL; +static int backtrace_stack(void *data, char *name) +{ + /* Yes, we want all stacks */ + return 0; +} - return head->ebp; +static void backtrace_address(void *data, unsigned long addr) +{ + unsigned int *depth = data; + + if ((*depth)--) + oprofile_add_trace(addr); } +static struct stacktrace_ops backtrace_ops = { + .warning = backtrace_warning, + .warning_symbol = backtrace_warning_symbol, + .stack = backtrace_stack, + .address = backtrace_address, +}; + +struct frame_head { + struct frame_head *ebp; + unsigned long ret; +} __attribute__((packed)); + static struct frame_head * dump_user_backtrace(struct frame_head * head) { @@ -53,72 +73,24 @@ dump_user_backtrace(struct frame_head * head) return bufhead[0].ebp; } -/* - * | | /\ Higher addresses - * | | - * --------------- stack base (address of current_thread_info) - * | thread info | - * . . - * | stack | - * --------------- saved regs->ebp value if valid (frame_head address) - * . . - * --------------- saved regs->rsp value if x86_64 - * | | - * --------------- struct pt_regs * stored on stack if 32-bit - * | | - * . . - * | | - * --------------- %esp - * | | - * | | \/ Lower addresses - * - * Thus, regs (or regs->rsp for x86_64) <-> stack base restricts the - * valid(ish) ebp values. Note: (1) for x86_64, NMI and several other - * exceptions use special stacks, maintained by the interrupt stack table - * (IST). These stacks are set up in trap_init() in - * arch/x86_64/kernel/traps.c. Thus, for x86_64, regs now does not point - * to the kernel stack; instead, it points to some location on the NMI - * stack. On the other hand, regs->rsp is the stack pointer saved when the - * NMI occurred. (2) For 32-bit, regs->esp is not valid because the - * processor does not save %esp on the kernel stack when interrupts occur - * in the kernel mode. - */ -#ifdef CONFIG_FRAME_POINTER -static int valid_kernel_stack(struct frame_head * head, struct pt_regs * regs) -{ - unsigned long headaddr = (unsigned long)head; -#ifdef CONFIG_X86_64 - unsigned long stack = (unsigned long)regs->rsp; -#else - unsigned long stack = (unsigned long)regs; -#endif - unsigned long stack_base = (stack & ~(THREAD_SIZE - 1)) + THREAD_SIZE; - - return headaddr > stack && headaddr < stack_base; -} -#else -/* without fp, it's just junk */ -static int valid_kernel_stack(struct frame_head * head, struct pt_regs * regs) -{ - return 0; -} -#endif - - void x86_backtrace(struct pt_regs * const regs, unsigned int depth) { struct frame_head *head; + unsigned long stack; #ifdef CONFIG_X86_64 head = (struct frame_head *)regs->rbp; + stack = regs->rsp; #else head = (struct frame_head *)regs->ebp; + stack = regs->esp; #endif if (!user_mode_vm(regs)) { - while (depth-- && valid_kernel_stack(head, regs)) - head = dump_kernel_backtrace(head); + if (depth) + dump_trace(NULL, regs, (unsigned long *)stack, + &backtrace_ops, &depth); return; } |
