From a53fd61ac2f411745471c1c877d5e072fbbf0e5c Mon Sep 17 00:00:00 2001 From: Aravinda Prasad Date: Sun, 4 Nov 2012 22:15:28 +0000 Subject: powerpc/ptrace: Enable hardware breakpoint upon re-registering On powerpc, ptrace will disable hardware breakpoint request once the breakpoint is hit. It is the responsibility of the caller to set it again. However, when the caller sets the hardware breakpoint again using ptrace(PTRACE_SET_DEBUGREG, child_pid, 0, addr), the hardware breakpoint is not enabled. While gdb's approach is to unregister and re-register the hardware breakpoint every time the breakpoint is hit - which is working fine, this could affect other programs trying to re-register hardware breakpoint without unregistering. This patch enables hardware breakpoint if the caller is re-registering. Signed-off-by: Aravinda Prasad Acked-by: Michael Neuling Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/ptrace.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch/powerpc/kernel/ptrace.c') diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c index 817b4116e5bb..c4970004d44d 100644 --- a/arch/powerpc/kernel/ptrace.c +++ b/arch/powerpc/kernel/ptrace.c @@ -952,6 +952,10 @@ int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, arch_bp_generic_fields(data & (DABR_DATA_WRITE | DABR_DATA_READ), &attr.bp_type); + + /* Enable breakpoint */ + attr.disabled = false; + ret = modify_user_hw_breakpoint(bp, &attr); if (ret) { ptrace_put_breakpoints(task); -- cgit v1.2.3