Re: [PATCH v2 07/16] powerpc/watchpoint: Get watchpoint count dynamically while disabling them

[Christophe Leroy]

Le 01/04/2020 à 08:13, Ravi Bangoria a écrit :

Instead of disabling only one watchpoint, get num of available
watchpoints dynamically and disable all of them.

Signed-off-by: Ravi Bangoria <ravi.bango...@linux.ibm.com>
---
  arch/powerpc/include/asm/hw_breakpoint.h | 15 +++++++--------
  1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/include/asm/hw_breakpoint.h 
b/arch/powerpc/include/asm/hw_breakpoint.h
index 4e4976c3248b..fae33c729ba9 100644
--- a/arch/powerpc/include/asm/hw_breakpoint.h
+++ b/arch/powerpc/include/asm/hw_breakpoint.h
@@ -78,14 +78,13 @@ extern void ptrace_triggered(struct perf_event *bp,
                        struct perf_sample_data *data, struct pt_regs *regs);
  static inline void hw_breakpoint_disable(void)
  {
-       struct arch_hw_breakpoint brk;
-
-       brk.address = 0;
-       brk.type = 0;
-       brk.len = 0;
-       brk.hw_len = 0;
-       if (ppc_breakpoint_available())
-               __set_breakpoint(&brk, 0);
+       int i;
+       struct arch_hw_breakpoint null_brk = {0};

Those declaration should be in the block unsigned them below.

+
+       if (ppc_breakpoint_available()) {
+               for (i = 0; i < nr_wp_slots(); i++)
+                       __set_breakpoint(&null_brk, i);
+       }

I would have had a preference to the following, but that's detail I guess:

        int i;
        struct arch_hw_breakpoint null_brk = {0};

        if (!ppc_breakpoint_available())
                return;

        for (i = 0; i < nr_wp_slots(); i++)
                __set_breakpoint(&null_brk, i);

  }
  extern void thread_change_pc(struct task_struct *tsk, struct pt_regs *regs);
  int hw_breakpoint_handler(struct die_args *args);

Christophe