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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/x86/oprofile/backtrace.c
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (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/x86/oprofile/backtrace.c')
-rw-r--r--kernel/arch/x86/oprofile/backtrace.c127
1 files changed, 127 insertions, 0 deletions
diff --git a/kernel/arch/x86/oprofile/backtrace.c b/kernel/arch/x86/oprofile/backtrace.c
new file mode 100644
index 000000000..4e664bdb5
--- /dev/null
+++ b/kernel/arch/x86/oprofile/backtrace.c
@@ -0,0 +1,127 @@
+/**
+ * @file backtrace.c
+ *
+ * @remark Copyright 2002 OProfile authors
+ * @remark Read the file COPYING
+ *
+ * @author John Levon
+ * @author David Smith
+ */
+
+#include <linux/oprofile.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/compat.h>
+#include <linux/uaccess.h>
+
+#include <asm/ptrace.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,
+ .walk_stack = print_context_stack,
+};
+
+#ifdef CONFIG_COMPAT
+static struct stack_frame_ia32 *
+dump_user_backtrace_32(struct stack_frame_ia32 *head)
+{
+ /* Also check accessibility of one struct frame_head beyond: */
+ struct stack_frame_ia32 bufhead[2];
+ struct stack_frame_ia32 *fp;
+ unsigned long bytes;
+
+ bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead));
+ if (bytes != 0)
+ return NULL;
+
+ fp = (struct stack_frame_ia32 *) compat_ptr(bufhead[0].next_frame);
+
+ oprofile_add_trace(bufhead[0].return_address);
+
+ /* frame pointers should strictly progress back up the stack
+ * (towards higher addresses) */
+ if (head >= fp)
+ return NULL;
+
+ return fp;
+}
+
+static inline int
+x86_backtrace_32(struct pt_regs * const regs, unsigned int depth)
+{
+ struct stack_frame_ia32 *head;
+
+ /* User process is IA32 */
+ if (!current || !test_thread_flag(TIF_IA32))
+ return 0;
+
+ head = (struct stack_frame_ia32 *) regs->bp;
+ while (depth-- && head)
+ head = dump_user_backtrace_32(head);
+
+ return 1;
+}
+
+#else
+static inline int
+x86_backtrace_32(struct pt_regs * const regs, unsigned int depth)
+{
+ return 0;
+}
+#endif /* CONFIG_COMPAT */
+
+static struct stack_frame *dump_user_backtrace(struct stack_frame *head)
+{
+ /* Also check accessibility of one struct frame_head beyond: */
+ struct stack_frame bufhead[2];
+ unsigned long bytes;
+
+ bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead));
+ if (bytes != 0)
+ return NULL;
+
+ oprofile_add_trace(bufhead[0].return_address);
+
+ /* frame pointers should strictly progress back up the stack
+ * (towards higher addresses) */
+ if (head >= bufhead[0].next_frame)
+ return NULL;
+
+ return bufhead[0].next_frame;
+}
+
+void
+x86_backtrace(struct pt_regs * const regs, unsigned int depth)
+{
+ struct stack_frame *head = (struct stack_frame *)frame_pointer(regs);
+
+ if (!user_mode(regs)) {
+ unsigned long stack = kernel_stack_pointer(regs);
+ if (depth)
+ dump_trace(NULL, regs, (unsigned long *)stack, 0,
+ &backtrace_ops, &depth);
+ return;
+ }
+
+ if (x86_backtrace_32(regs, depth))
+ return;
+
+ while (depth-- && head)
+ head = dump_user_backtrace(head);
+}