flush_ptrace_hw_breakpoint() destroys the counters set by ptrace, but "leaks" ->debugreg6 and ->ptrace_dr7. The problem is minor, but still it doesn't look right and flush_thread() did this until 66cb5917. Now that PTRACE_DETACH does flush_ too this makes even more sense. Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx> --- arch/x86/kernel/hw_breakpoint.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/arch/x86/kernel/hw_breakpoint.c b/arch/x86/kernel/hw_breakpoint.c index 02f0763..f66ff16 100644 --- a/arch/x86/kernel/hw_breakpoint.c +++ b/arch/x86/kernel/hw_breakpoint.c @@ -393,6 +393,9 @@ void flush_ptrace_hw_breakpoint(struct task_struct *tsk) unregister_hw_breakpoint(t->ptrace_bps[i]); t->ptrace_bps[i] = NULL; } + + t->debugreg6 = 0; + t->ptrace_dr7 = 0; } void hw_breakpoint_restore(void) -- 1.5.5.1 -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html