linux-kernel - [tip:x86/mm] x86/ftrace: Use __pa_symbol instead of _

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Message-ID: <tip-f38ad48f05973079aff40ac7a5a5ab463f7cee32@git.kernel.org>
Date:	Fri, 16 Nov 2012 16:27:57 -0800
From:	tip-bot for Alexander Duyck <alexander.h.duyck@...el.com>
To:	linux-tip-commits@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org, hpa@...or.com, mingo@...nel.org,
	fweisbec@...il.com, rostedt@...dmis.org,
	alexander.h.duyck@...el.com, tglx@...utronix.de,
	hpa@...ux.intel.com
Subject: [tip:x86/mm] x86/ftrace:
  Use __pa_symbol instead of __pa on C visible symbols

Commit-ID:  f38ad48f05973079aff40ac7a5a5ab463f7cee32
Gitweb:     http://git.kernel.org/tip/f38ad48f05973079aff40ac7a5a5ab463f7cee32
Author:     Alexander Duyck <alexander.h.duyck@...el.com>
AuthorDate: Fri, 16 Nov 2012 13:57:32 -0800
Committer:  H. Peter Anvin <hpa@...ux.intel.com>
CommitDate: Fri, 16 Nov 2012 15:20:43 -0800

x86/ftrace: Use __pa_symbol instead of __pa on C visible symbols

Instead of using __pa which is meant to be a general function for converting
virtual addresses to physical addresses we can use __pa_symbol which is the
preferred way of decoding kernel text virtual addresses to physical addresses.

In this case we are not directly converting C visible symbols however if we
know that the instruction pointer is somewhere between _text and _etext we
know that we are going to be translating an address form the kernel text
space.

Cc: Steven Rostedt <rostedt@...dmis.org>
Cc: Frederic Weisbecker <fweisbec@...il.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@...el.com>
Link: http://lkml.kernel.org/r/20121116215718.8521.24026.stgit@ahduyck-cp1.jf.intel.com
Signed-off-by: H. Peter Anvin <hpa@...ux.intel.com>
---
 arch/x86/kernel/ftrace.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 1d41402..42a392a 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -89,7 +89,7 @@ do_ftrace_mod_code(unsigned long ip, const void *new_code)
 	 * kernel identity mapping to modify code.
 	 */
 	if (within(ip, (unsigned long)_text, (unsigned long)_etext))
-		ip = (unsigned long)__va(__pa(ip));
+		ip = (unsigned long)__va(__pa_symbol(ip));
 
 	return probe_kernel_write((void *)ip, new_code, MCOUNT_INSN_SIZE);
 }
@@ -279,7 +279,7 @@ static int ftrace_write(unsigned long ip, const char *val, int size)
 	 * kernel identity mapping to modify code.
 	 */
 	if (within(ip, (unsigned long)_text, (unsigned long)_etext))
-		ip = (unsigned long)__va(__pa(ip));
+		ip = (unsigned long)__va(__pa_symbol(ip));
 
 	return probe_kernel_write((void *)ip, val, size);
 }
--
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