path: root/arch/powerpc/kernel/traps.c
diff options
authorK.Prasad <prasad@linux.vnet.ibm.com>2010-06-15 11:35:31 +0530
committerPaul Mackerras <paulus@samba.org>2010-06-22 19:40:50 +1000
commit2538c2d08f46141550a1e68819efa8fe31c6e3dc (patch)
treec84255fa8dbc9446d4ff546988adabc12450b880 /arch/powerpc/kernel/traps.c
parent5aae8a53708025d4e718f0d2e7c2f766779ddc71 (diff)
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 <prasad@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/kernel/traps.c')
1 files changed, 3 insertions, 5 deletions
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 25fc33984c2..e5fe5a8522a 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,
@@ -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)