lkml.org 
[lkml]   [2009]   [Aug]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] use __pa_symbol to calculate the address of a C symbol.
Date
The use of __pa() to calculate the address of a C-visible symbol
is wrong, and can lead to unpredictable results. See arch/x86/include/asm/page.h
for details.

It should be replaced with __pa_symbol(), that does the correct math here,
by taking relocations into account.

Signed-off-by: Glauber Costa <glommer@redhat.com>
---
arch/x86/kernel/kvmclock.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index 223af43..e5efcdc 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -50,8 +50,8 @@ static unsigned long kvm_get_wallclock(void)
struct timespec ts;
int low, high;

- low = (int)__pa(&wall_clock);
- high = ((u64)__pa(&wall_clock) >> 32);
+ low = (int)__pa_symbol(&wall_clock);
+ high = ((u64)__pa_symbol(&wall_clock) >> 32);
native_write_msr(MSR_KVM_WALL_CLOCK, low, high);

vcpu_time = &get_cpu_var(hv_clock);
--
1.6.2.2


\
 
 \ /
  Last update: 2009-08-31 13:07    [W:0.022 / U:0.032 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site