diff options
| author | Roland McGrath | 2008-01-30 13:30:54 +0100 |
|---|---|---|
| committer | Ingo Molnar | 2008-01-30 13:30:54 +0100 |
| commit | 7e9916040b3020d0f36d68bb7512e3b80b623097 (patch) | |
| tree | 7c391bcdb7a5d917b54ae968304e8a951997e16e /arch | |
| parent | x86: debugctlmsr kconfig (diff) | |
| download | kernel-qcow2-linux-7e9916040b3020d0f36d68bb7512e3b80b623097.tar.gz kernel-qcow2-linux-7e9916040b3020d0f36d68bb7512e3b80b623097.tar.xz kernel-qcow2-linux-7e9916040b3020d0f36d68bb7512e3b80b623097.zip | |
x86: debugctlmsr context switch
This adds low-level support for a per-thread value of MSR_IA32_DEBUGCTLMSR.
The per-thread value is switched in when TIF_DEBUGCTLMSR is set.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/process_32.c | 6 | ||||
| -rw-r--r-- | arch/x86/kernel/process_64.c | 3 |
2 files changed, 8 insertions, 1 deletions
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index d9905c9d0fd5..d5462f228daf 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -602,10 +602,14 @@ static noinline void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p, struct tss_struct *tss) { - struct thread_struct *next; + struct thread_struct *prev, *next; + prev = &prev_p->thread; next = &next_p->thread; + if (next->debugctlmsr != prev->debugctlmsr) + wrmsr(MSR_IA32_DEBUGCTLMSR, next->debugctlmsr, 0); + if (test_tsk_thread_flag(next_p, TIF_DEBUG)) { set_debugreg(next->debugreg[0], 0); set_debugreg(next->debugreg[1], 1); diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index f7356e5517f6..ae5eca17aa3c 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -555,6 +555,9 @@ static inline void __switch_to_xtra(struct task_struct *prev_p, prev = &prev_p->thread, next = &next_p->thread; + if (next->debugctlmsr != prev->debugctlmsr) + wrmsrl(MSR_IA32_DEBUGCTLMSR, next->debugctlmsr); + if (test_tsk_thread_flag(next_p, TIF_DEBUG)) { loaddebug(next, 0); loaddebug(next, 1); |