diff options
author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
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committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/avr32/oprofile/backtrace.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/avr32/oprofile/backtrace.c')
-rw-r--r-- | kernel/arch/avr32/oprofile/backtrace.c | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/kernel/arch/avr32/oprofile/backtrace.c b/kernel/arch/avr32/oprofile/backtrace.c new file mode 100644 index 000000000..75d9ad6f9 --- /dev/null +++ b/kernel/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); + } +} + + |