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authorGerald Britton <gbritton@alum.mit.edu>2006-02-14 10:19:04 -0500
committerLinus Torvalds <torvalds@g5.osdl.org>2006-02-14 11:25:29 -0500
commit303794400992b907b7cac0d91788603636c7e0fe (patch)
tree012781f808f48d80b32e435a4f27b6e8524d0ff0 /arch/i386/oprofile/backtrace.c
parentb739db79a434aec89027a109d85de305e6bdeb93 (diff)
[PATCH] x86: fix oprofile kernel callgraph regression
Fix x86 oprofile regression introduced by: commit c34d1b4d165c67b966bca4aba026443d7ff161eb [PATCH] mm: kill check_user_page_readable That commit reorganized tests for the userspace stack walking moving all those tests into dump_backtrace(), however, dump_backtrace() was used for both userspace and kernel stalk walking. The result is typically no recorded callgraph information for kernel samples. Revive the original function as dump_kernel_backtrace() and rename the other to dump_user_backtrace() to avoid future confusion. Signed-off-by: Gerald Britton <gbritton@alum.mit.edu> Apology-from: Hugh Dickins <hugh@veritas.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/i386/oprofile/backtrace.c')
-rw-r--r--arch/i386/oprofile/backtrace.c19
1 files changed, 16 insertions, 3 deletions
diff --git a/arch/i386/oprofile/backtrace.c b/arch/i386/oprofile/backtrace.c
index acc18138fb22..c049ce414f01 100644
--- a/arch/i386/oprofile/backtrace.c
+++ b/arch/i386/oprofile/backtrace.c
@@ -20,7 +20,20 @@ struct frame_head {
20} __attribute__((packed)); 20} __attribute__((packed));
21 21
22static struct frame_head * 22static struct frame_head *
23dump_backtrace(struct frame_head * head) 23dump_kernel_backtrace(struct frame_head * head)
24{
25 oprofile_add_trace(head->ret);
26
27 /* frame pointers should strictly progress back up the stack
28 * (towards higher addresses) */
29 if (head >= head->ebp)
30 return NULL;
31
32 return head->ebp;
33}
34
35static struct frame_head *
36dump_user_backtrace(struct frame_head * head)
24{ 37{
25 struct frame_head bufhead[2]; 38 struct frame_head bufhead[2];
26 39
@@ -105,10 +118,10 @@ x86_backtrace(struct pt_regs * const regs, unsigned int depth)
105 118
106 if (!user_mode_vm(regs)) { 119 if (!user_mode_vm(regs)) {
107 while (depth-- && valid_kernel_stack(head, regs)) 120 while (depth-- && valid_kernel_stack(head, regs))
108 head = dump_backtrace(head); 121 head = dump_kernel_backtrace(head);
109 return; 122 return;
110 } 123 }
111 124
112 while (depth-- && head) 125 while (depth-- && head)
113 head = dump_backtrace(head); 126 head = dump_user_backtrace(head);
114} 127}