[PATCH v3 5/8] x86/ftrace: Use __pa_symbol instead of __pa on C visible symbols

Alexander Duyck
2012-11-05T19:05:37Z

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@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
---

arch/x86/kernel/ftrace.c | 4 ++--
1 files 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);
}