diff options
Diffstat (limited to 'arch/x86/kernel/step.c')
| -rw-r--r-- | arch/x86/kernel/step.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/arch/x86/kernel/step.c b/arch/x86/kernel/step.c index 2ef1a5f8d67..071ff479823 100644 --- a/arch/x86/kernel/step.c +++ b/arch/x86/kernel/step.c @@ -140,6 +140,9 @@ static int enable_single_step(struct task_struct *child) */ static void write_debugctlmsr(struct task_struct *child, unsigned long val) { + if (child->thread.debugctlmsr == val) + return; + child->thread.debugctlmsr = val; if (child != current) @@ -165,11 +168,11 @@ static void enable_step(struct task_struct *child, bool block) write_debugctlmsr(child, child->thread.debugctlmsr | DEBUGCTLMSR_BTF); } else { - write_debugctlmsr(child, - child->thread.debugctlmsr & ~TIF_DEBUGCTLMSR); + write_debugctlmsr(child, + child->thread.debugctlmsr & ~DEBUGCTLMSR_BTF); - if (!child->thread.debugctlmsr) - clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR); + if (!child->thread.debugctlmsr) + clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR); } } @@ -189,7 +192,7 @@ void user_disable_single_step(struct task_struct *child) * Make sure block stepping (BTF) is disabled. */ write_debugctlmsr(child, - child->thread.debugctlmsr & ~TIF_DEBUGCTLMSR); + child->thread.debugctlmsr & ~DEBUGCTLMSR_BTF); if (!child->thread.debugctlmsr) clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR); |