From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Ingo Molnar <mingo@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
"H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Subject: [RFC][PATCH 4/9 v2] ftrace/x86: Have save_mcount_regs store RIP in %rdi for first parameter
Date: Tue, 25 Nov 2014 06:50:07 -0500 [thread overview]
Message-ID: <20141125115129.739619857@goodmis.org> (raw)
In-Reply-To: 20141125115003.856641273@goodmis.org
[-- Attachment #1: 0004-ftrace-x86-Have-save_mcount_regs-store-RIP-in-rdi-fo.patch --]
[-- Type: text/plain, Size: 1412 bytes --]
From: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org>
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
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
arch/x86/kernel/mcount_64.S | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kernel/mcount_64.S b/arch/x86/kernel/mcount_64.S
index 0a693d011980..4f1b27642495 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
--
2.1.1
next prev parent reply other threads:[~2014-11-25 11:51 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-25 11:50 [RFC][PATCH 0/9 v2] ftrace/x86: Clean up of mcount.S code Steven Rostedt
2014-11-25 11:50 ` [RFC][PATCH 1/9 v2] ftrace/x86: Have static tracing also use ftrace_caller_setup Steven Rostedt
2014-11-25 11:50 ` [RFC][PATCH 2/9 v2] ftrace/x86: Move MCOUNT_SAVE_FRAME out of header file Steven Rostedt
2014-11-25 11:50 ` [RFC][PATCH 3/9 v2] ftrace/x86: Rename MCOUNT_SAVE_FRAME and add more detailed comments Steven Rostedt
2014-11-25 11:50 ` Steven Rostedt [this message]
2014-11-25 11:50 ` [RFC][PATCH 5/9 v2] ftrace/x86: Simplify save_mcount_regs on getting RIP Steven Rostedt
2014-11-25 11:50 ` [RFC][PATCH 6/9 v2] ftrace/x86: Add macro MCOUNT_REG_SIZE for amount of stack used to save mcount regs Steven Rostedt
2014-11-25 11:50 ` [RFC][PATCH 7/9 v2] ftrace/x86: Have save_mcount_regs macro also save stack frames if needed Steven Rostedt
2014-11-25 11:50 ` [RFC][PATCH 8/9 v2] ftrace/x86: Get rid of ftrace_caller_setup Steven Rostedt
2014-11-25 11:50 ` [RFC][PATCH 9/9 v2] ftrace/fgraph/x86: Have prepare_ftrace_return() take ip as first parameter Steven Rostedt
2014-11-25 17:36 ` [RFC][PATCH 0/9 v2] ftrace/x86: Clean up of mcount.S code Linus Torvalds
2014-11-26 22:03 ` Thomas Gleixner
2014-11-26 22:05 ` Thomas Gleixner
2014-11-26 23:13 ` Steven Rostedt
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