diff options
author | Arjan van de Ven <arjan@linux.intel.com> | 2008-10-17 09:20:26 -0700 |
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committer | Arjan van de Ven <arjan@linux.intel.com> | 2008-10-17 09:20:26 -0700 |
commit | 651dab4264e4ba0e563f5ff56f748127246e9065 (patch) | |
tree | 016630974bdcb00fe529b673f96d389e0fd6dc94 /arch/avr32/oprofile/backtrace.c | |
parent | 40b8606253552109815786e5d4b0de98782d31f5 (diff) | |
parent | 2e532d68a2b3e2aa6b19731501222069735c741c (diff) |
Merge commit 'linus/master' into merge-linus
Conflicts:
arch/x86/kvm/i8254.c
Diffstat (limited to 'arch/avr32/oprofile/backtrace.c')
-rw-r--r-- | arch/avr32/oprofile/backtrace.c | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/arch/avr32/oprofile/backtrace.c b/arch/avr32/oprofile/backtrace.c new file mode 100644 index 00000000000..75d9ad6f99c --- /dev/null +++ b/arch/avr32/oprofile/backtrace.c @@ -0,0 +1,81 @@ +/* + * AVR32 specific backtracing code for oprofile + * + * Copyright 2008 Weinmann GmbH + * + * Author: Nikolaus Voss <n.voss@weinmann.de> + * + * Based on i386 oprofile backtrace code by John Levon and David Smith + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#include <linux/oprofile.h> +#include <linux/sched.h> +#include <linux/uaccess.h> + +/* The first two words of each frame on the stack look like this if we have + * frame pointers */ +struct frame_head { + unsigned long lr; + struct frame_head *fp; +}; + +/* copied from arch/avr32/kernel/process.c */ +static inline int valid_stack_ptr(struct thread_info *tinfo, unsigned long p) +{ + return (p > (unsigned long)tinfo) + && (p < (unsigned long)tinfo + THREAD_SIZE - 3); +} + +/* copied from arch/x86/oprofile/backtrace.c */ +static struct frame_head *dump_user_backtrace(struct frame_head *head) +{ + struct frame_head bufhead[2]; + + /* Also check accessibility of one struct frame_head beyond */ + if (!access_ok(VERIFY_READ, head, sizeof(bufhead))) + return NULL; + if (__copy_from_user_inatomic(bufhead, head, sizeof(bufhead))) + return NULL; + + oprofile_add_trace(bufhead[0].lr); + + /* frame pointers should strictly progress back up the stack + * (towards higher addresses) */ + if (bufhead[0].fp <= head) + return NULL; + + return bufhead[0].fp; +} + +void avr32_backtrace(struct pt_regs * const regs, unsigned int depth) +{ + /* Get first frame pointer */ + struct frame_head *head = (struct frame_head *)(regs->r7); + + if (!user_mode(regs)) { +#ifdef CONFIG_FRAME_POINTER + /* + * Traverse the kernel stack from frame to frame up to + * "depth" steps. + */ + while (depth-- && valid_stack_ptr(task_thread_info(current), + (unsigned long)head)) { + oprofile_add_trace(head->lr); + if (head->fp <= head) + break; + head = head->fp; + } +#endif + } else { + /* Assume we have frame pointers in user mode process */ + while (depth-- && head) + head = dump_user_backtrace(head); + } +} + + |