Commit-ID: e6928e58d4d4a02f88838945f792c107623314ac
Gitweb: http://git.kernel.org/tip/e6928e58d4d4a02f88838945f792c107623314ac
Author: Steven Rostedt (VMware) <[email protected]>
AuthorDate: Thu, 23 Mar 2017 10:33:50 -0400
Committer: Thomas Gleixner <[email protected]>
CommitDate: Fri, 24 Mar 2017 10:14:07 +0100
x86/ftrace: Add stack frame pointer to ftrace_caller
The function hook ftrace_caller does not create its own stack frame, and
this causes the ftrace stack trace to miss the first function when doing
stack traces.
# echo schedule:stacktrace > /sys/kernel/tracing/set_ftrace_filter
Before:
<idle>-0 [002] .N.. 29.865807: <stack trace>
=> cpu_startup_entry
=> start_secondary
=> startup_32_smp
<...>-7 [001] .... 29.866509: <stack trace>
=> kthread
=> ret_from_fork
<...>-1 [000] .... 29.865377: <stack trace>
=> poll_schedule_timeout
=> do_select
=> core_sys_select
=> SyS_select
=> do_fast_syscall_32
=> entry_SYSENTER_32
After:
<idle>-0 [002] .N.. 31.234853: <stack trace>
=> do_idle
=> cpu_startup_entry
=> start_secondary
=> startup_32_smp
<...>-7 [003] .... 31.235140: <stack trace>
=> rcu_gp_kthread
=> kthread
=> ret_from_fork
<...>-1819 [000] .... 31.264172: <stack trace>
=> schedule_hrtimeout_range
=> poll_schedule_timeout
=> do_sys_poll
=> SyS_ppoll
=> do_fast_syscall_32
=> entry_SYSENTER_32
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
Reviewed-by: Josh Poimboeuf <[email protected]>
Reviewed-by: Masami Hiramatsu <[email protected]>
Reviewed-by: Ingo Molnar <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Thomas Gleixner <[email protected]>
---
arch/x86/kernel/ftrace_32.S | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/ftrace_32.S b/arch/x86/kernel/ftrace_32.S
index 2b160f2..a4e2872 100644
--- a/arch/x86/kernel/ftrace_32.S
+++ b/arch/x86/kernel/ftrace_32.S
@@ -16,12 +16,19 @@ ENTRY(mcount)
END(mcount)
ENTRY(ftrace_caller)
+
+ pushl %ebp
+ movl %esp, %ebp
+
pushl %eax
pushl %ecx
pushl %edx
pushl $0 /* Pass NULL as regs pointer */
- movl 4*4(%esp), %eax
- movl 0x4(%ebp), %edx
+ movl 5*4(%esp), %eax
+ /* Copy original ebp into %edx */
+ movl 4*4(%esp), %edx
+ /* Get the parent ip */
+ movl 0x4(%edx), %edx
movl function_trace_op, %ecx
subl $MCOUNT_INSN_SIZE, %eax
@@ -33,6 +40,7 @@ ftrace_call:
popl %edx
popl %ecx
popl %eax
+ popl %ebp
.Lftrace_ret:
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
.globl ftrace_graph_call
