From 2538c2d08f46141550a1e68819efa8fe31c6e3dc Mon Sep 17 00:00:00 2001 From: "K.Prasad" Date: Tue, 15 Jun 2010 11:35:31 +0530 Subject: powerpc, hw_breakpoint: Handle concurrent alignment interrupts If an alignment interrupt occurs on an instruction that is being single-stepped, the alignment interrupt handler currently handles the single-step condition by unconditionally sending a SIGTRAP to the process. Other synchronous interrupts that result in the instruction being emulated do likewise. With hw_breakpoint support, the hw_breakpoint code needs to be able to intercept these single-step events as well as those where the instruction executes normally and a trace interrupt happens. Fix this by making emulate_single_step() use the existing single_step_exception() function instead of calling _exception() directly. We then make single_step_exception() use the abstracted clear_single_step() rather than clearing bits in the MSR image directly so that emulate_single_step() will continue to work correctly on Book 3E processors. Signed-off-by: K.Prasad Signed-off-by: Paul Mackerras --- arch/powerpc/kernel/traps.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) (limited to 'arch') diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index 25fc33984c2b..e5fe5a8522a6 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -688,7 +688,7 @@ void RunModeException(struct pt_regs *regs) void __kprobes single_step_exception(struct pt_regs *regs) { - regs->msr &= ~(MSR_SE | MSR_BE); /* Turn off 'trace' bits */ + clear_single_step(regs); if (notify_die(DIE_SSTEP, "single_step", regs, 5, 5, SIGTRAP) == NOTIFY_STOP) @@ -707,10 +707,8 @@ void __kprobes single_step_exception(struct pt_regs *regs) */ static void emulate_single_step(struct pt_regs *regs) { - if (single_stepping(regs)) { - clear_single_step(regs); - _exception(SIGTRAP, regs, TRAP_TRACE, 0); - } + if (single_stepping(regs)) + single_step_exception(regs); } static inline int __parse_fpscr(unsigned long fpscr) -- cgit v1.2.3