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ftrace/x86: Load ftrace_ops in parameter not the variable holding it
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Function tracing callbacks expect to have the ftrace_ops that registered it
passed to them, not the address of the variable that holds the ftrace_ops
that registered it.

Use a mov instead of a lea to store the ftrace_ops into the parameter
of the function tracing callback.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Link: http://lkml.kernel.org/r/20131113152004.459787f9@gandalf.local.home
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org> # v3.8+
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Steven Rostedt authored and H. Peter Anvin committed Jan 9, 2014
1 parent d6e0a2d commit 1739f09
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Showing 2 changed files with 3 additions and 3 deletions.
4 changes: 2 additions & 2 deletions arch/x86/kernel/entry_32.S
Original file line number Diff line number Diff line change
Expand Up @@ -1082,7 +1082,7 @@ ENTRY(ftrace_caller)
pushl $0 /* Pass NULL as regs pointer */
movl 4*4(%esp), %eax
movl 0x4(%ebp), %edx
leal function_trace_op, %ecx
movl function_trace_op, %ecx
subl $MCOUNT_INSN_SIZE, %eax

.globl ftrace_call
Expand Down Expand Up @@ -1140,7 +1140,7 @@ ENTRY(ftrace_regs_caller)
movl 12*4(%esp), %eax /* Load ip (1st parameter) */
subl $MCOUNT_INSN_SIZE, %eax /* Adjust ip */
movl 0x4(%ebp), %edx /* Load parent ip (2nd parameter) */
leal function_trace_op, %ecx /* Save ftrace_pos in 3rd parameter */
movl function_trace_op, %ecx /* Save ftrace_pos in 3rd parameter */
pushl %esp /* Save pt_regs as 4th parameter */

GLOBAL(ftrace_regs_call)
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2 changes: 1 addition & 1 deletion arch/x86/kernel/entry_64.S
Original file line number Diff line number Diff line change
Expand Up @@ -88,7 +88,7 @@ END(function_hook)
MCOUNT_SAVE_FRAME \skip

/* Load the ftrace_ops into the 3rd parameter */
leaq function_trace_op, %rdx
movq function_trace_op(%rip), %rdx

/* Load ip into the first parameter */
movq RIP(%rsp), %rdi
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