aboutsummaryrefslogtreecommitdiffstats
path: root/arch/x86/kernel/step.c
diff options
context:
space:
mode:
authorJan Beulich <jbeulich@novell.com>2008-03-10 09:11:17 -0400
committerIngo Molnar <mingo@elte.hu>2008-04-17 11:40:58 -0400
commit5b0e508415a83989fe704b4718a1a214bc333ca7 (patch)
treebf73f1e6b944c190441413cedfb49b05e04ffe6b /arch/x86/kernel/step.c
parentf694010185c429629ad5a65245da08103e611852 (diff)
x86: prevent unconditional writes to DebugCtl MSR
Otherwise, enabling (or better, subsequent disabling) of single stepping would cause a kernel oops on CPUs not having this MSR. The patch could have been added a conditional to the MSR write in user_disable_single_step(), but centralizing the updates seems safer and (looking forward) better manageable. Signed-off-by: Jan Beulich <jbeulich@novell.com> Cc: Markus Metzger <markus.t.metzger@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/step.c')
-rw-r--r--arch/x86/kernel/step.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/step.c b/arch/x86/kernel/step.c
index 071ff4798236..92c20fee6781 100644
--- a/arch/x86/kernel/step.c
+++ b/arch/x86/kernel/step.c
@@ -148,7 +148,7 @@ static void write_debugctlmsr(struct task_struct *child, unsigned long val)
148 if (child != current) 148 if (child != current)
149 return; 149 return;
150 150
151 wrmsrl(MSR_IA32_DEBUGCTLMSR, val); 151 update_debugctlmsr(val);
152} 152}
153 153
154/* 154/*