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authorSteven Rostedt (Red Hat) <rostedt@goodmis.org>2014-11-24 13:21:09 -0500
committerSteven Rostedt <rostedt@goodmis.org>2014-12-01 14:07:39 -0500
commit094dfc545139510f251b9595850aa63fe2a8c131 (patch)
tree1d92fc26e6a38cbd3938e1ab1fe2fbf5584bfb7a
parent05df710ec343cf351475e86bfaf89938e5114d69 (diff)
downloadop-kernel-dev-094dfc545139510f251b9595850aa63fe2a8c131.zip
op-kernel-dev-094dfc545139510f251b9595850aa63fe2a8c131.tar.gz
ftrace/x86: Have save_mcount_regs store RIP in %rdi for first parameter
Instead of having save_mcount_regs store the RIP in %rdx as a temp register to place it in the proper location of the pt_regs on the stack. Use the %rdi register as the temp register. This lets us remove the extra store in the ftrace_caller_setup macro. Link: http://lkml.kernel.org/r/CA+55aFwF+qCGSKdGaEgW4p6N65GZ5_XTV=1NbtWDvxnd5yYLiw@mail.gmail.com Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r--arch/x86/kernel/mcount_64.S7
1 files changed, 3 insertions, 4 deletions
diff --git a/arch/x86/kernel/mcount_64.S b/arch/x86/kernel/mcount_64.S
index 0a693d0..4f1b276 100644
--- a/arch/x86/kernel/mcount_64.S
+++ b/arch/x86/kernel/mcount_64.S
@@ -51,8 +51,8 @@
movq %r8, R8(%rsp)
movq %r9, R9(%rsp)
/* Move RIP to its proper location */
- movq SS+8(%rsp), %rdx
- movq %rdx, RIP(%rsp)
+ movq SS+8(%rsp), %rdi
+ movq %rdi, RIP(%rsp)
.endm
.macro restore_mcount_regs skip=0
@@ -75,8 +75,7 @@ GLOBAL(\trace_label)
/* Load the ftrace_ops into the 3rd parameter */
movq function_trace_op(%rip), %rdx
- /* Load ip into the first parameter */
- movq RIP(%rsp), %rdi
+ /* %rdi already has %rip from the save_mcount_regs macro */
subq $MCOUNT_INSN_SIZE, %rdi
/* Load the parent_ip into the second parameter */
#ifdef CC_USING_FENTRY
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