diff options
| -rw-r--r-- | arch/powerpc/include/asm/hw_breakpoint.h | 3 | ||||
| -rw-r--r-- | arch/powerpc/kernel/hw_breakpoint.c | 18 | ||||
| -rw-r--r-- | arch/powerpc/kernel/signal.c | 3 |
3 files changed, 24 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/hw_breakpoint.h b/arch/powerpc/include/asm/hw_breakpoint.h index b111713b593e..6576bad1069c 100644 --- a/arch/powerpc/include/asm/hw_breakpoint.h +++ b/arch/powerpc/include/asm/hw_breakpoint.h @@ -65,9 +65,12 @@ static inline void hw_breakpoint_disable(void) { set_dabr(0); } +extern void thread_change_pc(struct task_struct *tsk, struct pt_regs *regs); #else /* CONFIG_HAVE_HW_BREAKPOINT */ static inline void hw_breakpoint_disable(void) { } +static inline void thread_change_pc(struct task_struct *tsk, + struct pt_regs *regs) { } #endif /* CONFIG_HAVE_HW_BREAKPOINT */ #endif /* __KERNEL__ */ #endif /* _PPC_BOOK3S_64_HW_BREAKPOINT_H */ diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c index 7a2ad5e84c16..7bd01a56d194 100644 --- a/arch/powerpc/kernel/hw_breakpoint.c +++ b/arch/powerpc/kernel/hw_breakpoint.c @@ -175,6 +175,24 @@ int arch_validate_hwbkpt_settings(struct perf_event *bp) } /* + * Restores the breakpoint on the debug registers. + * Invoke this function if it is known that the execution context is + * about to change to cause loss of MSR_SE settings. + */ +void thread_change_pc(struct task_struct *tsk, struct pt_regs *regs) +{ + struct arch_hw_breakpoint *info; + + if (likely(!tsk->thread.last_hit_ubp)) + return; + + info = counter_arch_bp(tsk->thread.last_hit_ubp); + regs->msr &= ~MSR_SE; + set_dabr(info->address | info->type | DABR_TRANSLATION); + tsk->thread.last_hit_ubp = NULL; +} + +/* * Handle debug exception notifications. */ int __kprobes hw_breakpoint_handler(struct die_args *args) diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c index a0afb555a7c9..7109f5b1baa8 100644 --- a/arch/powerpc/kernel/signal.c +++ b/arch/powerpc/kernel/signal.c @@ -11,6 +11,7 @@ #include <linux/tracehook.h> #include <linux/signal.h> +#include <asm/hw_breakpoint.h> #include <asm/uaccess.h> #include <asm/unistd.h> @@ -149,6 +150,8 @@ static int do_signal_pending(sigset_t *oldset, struct pt_regs *regs) if (current->thread.dabr) set_dabr(current->thread.dabr); #endif + /* Re-enable the breakpoints for the signal stack */ + thread_change_pc(current, regs); if (is32) { if (ka.sa.sa_flags & SA_SIGINFO) |