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/sh/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/sh/oprofile/backtrace.c')
-rw-r--r-- | kernel/arch/sh/oprofile/backtrace.c | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/kernel/arch/sh/oprofile/backtrace.c b/kernel/arch/sh/oprofile/backtrace.c new file mode 100644 index 000000000..9c88dcd56 --- /dev/null +++ b/kernel/arch/sh/oprofile/backtrace.c @@ -0,0 +1,91 @@ +/* + * SH specific backtracing code for oprofile + * + * Copyright 2007 STMicroelectronics Ltd. + * + * Author: Dave Peverley <dpeverley@mpc-data.co.uk> + * + * Based on ARM oprofile backtrace code by Richard Purdie and in turn, i386 + * oprofile backtrace code by John Levon, 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/kallsyms.h> +#include <linux/mm.h> +#include <asm/unwinder.h> +#include <asm/ptrace.h> +#include <asm/uaccess.h> +#include <asm/sections.h> +#include <asm/stacktrace.h> + +static int backtrace_stack(void *data, char *name) +{ + /* Yes, we want all stacks */ + return 0; +} + +static void backtrace_address(void *data, unsigned long addr, int reliable) +{ + unsigned int *depth = data; + + if ((*depth)--) + oprofile_add_trace(addr); +} + +static struct stacktrace_ops backtrace_ops = { + .stack = backtrace_stack, + .address = backtrace_address, +}; + +/* Limit to stop backtracing too far. */ +static int backtrace_limit = 20; + +static unsigned long * +user_backtrace(unsigned long *stackaddr, struct pt_regs *regs) +{ + unsigned long buf_stack; + + /* Also check accessibility of address */ + if (!access_ok(VERIFY_READ, stackaddr, sizeof(unsigned long))) + return NULL; + + if (__copy_from_user_inatomic(&buf_stack, stackaddr, sizeof(unsigned long))) + return NULL; + + /* Quick paranoia check */ + if (buf_stack & 3) + return NULL; + + oprofile_add_trace(buf_stack); + + stackaddr++; + + return stackaddr; +} + +void sh_backtrace(struct pt_regs * const regs, unsigned int depth) +{ + unsigned long *stackaddr; + + /* + * Paranoia - clip max depth as we could get lost in the weeds. + */ + if (depth > backtrace_limit) + depth = backtrace_limit; + + stackaddr = (unsigned long *)kernel_stack_pointer(regs); + if (!user_mode(regs)) { + if (depth) + unwind_stack(NULL, regs, stackaddr, + &backtrace_ops, &depth); + return; + } + + while (depth-- && (stackaddr != NULL)) + stackaddr = user_backtrace(stackaddr, regs); +} |