powerpc/watchpoints: Simplify watchpoint reinsertion

We only remove watchpoints when they have the perf_single_step flag set,
so we can reinsert them during the first iteration.

Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230801011744.153973-5-bgray@linux.ibm.com

diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index 624375c1888202f39dc6436d6a93d33b112f9cd7..bf8dda1a7e040fc60975eaa16fc90e3ac224a830 100644 (file)
--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c
@@ -772,16 +772,6 @@ static int single_step_dabr_instruction(struct die_args *args)
                        perf_bp_event(bp, regs);
 
                info->perf_single_step = false;
-       }
-
-       if (!found)
-               return NOTIFY_DONE;
-
-       for (int i = 0; i < nr_wp_slots(); i++) {
-               struct perf_event *bp = __this_cpu_read(bp_per_reg[i]);
-               if (!bp)
-                       continue;
-
                __set_breakpoint(i, counter_arch_bp(bp));
        }
 
@@ -789,7 +779,7 @@ static int single_step_dabr_instruction(struct die_args *args)
         * If the process was being single-stepped by ptrace, let the
         * other single-step actions occur (e.g. generate SIGTRAP).
         */
-       if (test_thread_flag(TIF_SINGLESTEP))
+       if (!found || test_thread_flag(TIF_SINGLESTEP))
                return NOTIFY_DONE;
 
        return NOTIFY_STOP;