diff options
Diffstat (limited to 'runtime/stack.c')
| -rw-r--r-- | runtime/stack.c | 101 |
1 files changed, 92 insertions, 9 deletions
diff --git a/runtime/stack.c b/runtime/stack.c index e63d1d8b..f06475dc 100644 --- a/runtime/stack.c +++ b/runtime/stack.c @@ -14,16 +14,85 @@ static int (*_stp_kta)(unsigned long addr)=(void *)KTA; + +struct frame_head { + struct frame_head * ebp; + unsigned long ret; +} __attribute__((packed)); + +static struct frame_head * +dump_backtrace(struct frame_head * head) +{ + _stp_printf ("db: %lx\n", head->ret); + + /* frame pointers should strictly progress back up the stack + * (towards higher addresses) */ + if (head >= head->ebp) + return NULL; + + return head->ebp; +} + +static int pages_present(struct frame_head * head) +{ + struct mm_struct * mm = current->mm; + + /* FIXME: only necessary once per page */ + if (!check_user_page_readable(mm, (unsigned long)head)) + return 0; + + return check_user_page_readable(mm, (unsigned long)(head + 1)); +} + +static int valid_kernel_stack(struct frame_head * head, struct pt_regs * regs) +{ + unsigned long headaddr = (unsigned long)head; + unsigned long stack = (unsigned long)regs; + unsigned long stack_base = (stack & ~(THREAD_SIZE - 1)) + THREAD_SIZE; + _stp_log ("%lx %lx %lx\n", headaddr, stack, stack_base); + return headaddr < stack_base; +} + +void +x86_backtrace(struct pt_regs * const regs, unsigned int depth) +{ + struct frame_head *head; + +#ifdef CONFIG_X86_64 + head = (struct frame_head *)regs->rbp; +#else + head = (struct frame_head *)regs->ebp; +#endif + + if (!user_mode(regs)) { + _stp_log ("kernel mode\n"); + while (depth-- && valid_kernel_stack(head, regs)) + head = dump_backtrace(head); + _stp_print_flush(); + return; + } + +#ifdef CONFIG_SMP + if (!spin_trylock(¤t->mm->page_table_lock)) + return; +#endif + + while (depth-- && head && pages_present(head)) + head = dump_backtrace(head); + +#ifdef CONFIG_SMP + spin_unlock(¤t->mm->page_table_lock); +#endif + _stp_print_flush(); +} + + #ifdef __x86_64__ static void __stp_stack_print (unsigned long *stack, int verbose, int levels) { unsigned long addr; - - if (verbose) - _stp_printf ("trace for %d (%s)\n", current->pid, current->comm); - while (((long) stack & (THREAD_SIZE-1)) != 0) { - addr = *stack++; + addr = *stack; if (_stp_kta(addr)) { if (verbose) { _stp_symbol_print (addr); @@ -31,6 +100,7 @@ static void __stp_stack_print (unsigned long *stack, int verbose, int levels) } else _stp_printf ("0x%lx ", addr); } + stack++; } _stp_print_flush(); } @@ -42,10 +112,11 @@ static void __stp_stack_sprint (String str, unsigned long *stack, int verbose, i while (((long) stack & (THREAD_SIZE-1)) != 0) { addr = *stack++; if (_stp_kta(addr)) { - if (verbose) + if (verbose) { _stp_symbol_sprint (str, addr); - else - _stp_sprintf (str, "0x%lx ", addr); + _stp_sprintf (str, "\n"); + } else + _stp_sprintf (str, "0x%lx\n", addr); } } } @@ -153,12 +224,24 @@ static void __stp_stack_sprint (String str, unsigned long *stack, int verbose, i * @bug levels parameter is not functional */ -void _stp_stack_print (int verbose, int levels) +void _stp_stack_jprint (int verbose, int levels) { unsigned long stack; __stp_stack_print (&stack, verbose, levels); } +void _stp_stack_print (struct pt_regs *regs, int verbose, int levels) +{ + if (verbose) { + _stp_printf ("trace for %d (%s)\n", current->pid, current->comm); + _stp_symbol_print (regs->rip); + _stp_print ("\n"); + } else + _stp_printf ("0x%lx ", regs->rip); + + __stp_stack_print ((unsigned long *)regs->rsp, verbose, levels); +} + /** Writes stack dump to a String * * @param str String |