Re: [PATCH] hw_breakpoint: Fix build warnings with clang

Christophe Leroy [off-list ref] writes:

Le 02/06/2020 à 06:12, Ravi Bangoria a écrit :

quoted

kbuild test robot reported few build warnings with hw_breakpoint code
when compiled with clang[1]. Fix those.

[1]: https://lore.kernel.org/linuxppc-dev/202005192233.oi9CjRtA%25lkp@intel.com/ (local)

This should have mentioned that some of the errors were recently
introduced by your commit.

quoted

Reported-by: kbuild test robot <redacted>
Signed-off-by: Ravi Bangoria <redacted>
---
Note: Prepared on top of powerpc/next.

  arch/powerpc/include/asm/hw_breakpoint.h | 3 ---
  include/linux/hw_breakpoint.h            | 4 ++++
  2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/include/asm/hw_breakpoint.h b/arch/powerpc/include/asm/hw_breakpoint.h
index f42a55eb77d2..cb424799da0d 100644
--- a/arch/powerpc/include/asm/hw_breakpoint.h
+++ b/arch/powerpc/include/asm/hw_breakpoint.h

@@ -70,9 +70,6 @@ extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
  						unsigned long val, void *data);
  int arch_install_hw_breakpoint(struct perf_event *bp);
  void arch_uninstall_hw_breakpoint(struct perf_event *bp);
-int arch_reserve_bp_slot(struct perf_event *bp);
-void arch_release_bp_slot(struct perf_event *bp);
-void arch_unregister_hw_breakpoint(struct perf_event *bp);
  void hw_breakpoint_pmu_read(struct perf_event *bp);
  extern void flush_ptrace_hw_breakpoint(struct task_struct *tsk);
  

diff --git a/include/linux/hw_breakpoint.h b/include/linux/hw_breakpoint.h
index 6058c3844a76..521481f0d320 100644
--- a/include/linux/hw_breakpoint.h
+++ b/include/linux/hw_breakpoint.h

@@ -80,6 +80,10 @@ extern int dbg_reserve_bp_slot(struct perf_event *bp);
  extern int dbg_release_bp_slot(struct perf_event *bp);
  extern int reserve_bp_slot(struct perf_event *bp);
  extern void release_bp_slot(struct perf_event *bp);
+extern int hw_breakpoint_weight(struct perf_event *bp);
+extern int arch_reserve_bp_slot(struct perf_event *bp);
+extern void arch_release_bp_slot(struct perf_event *bp);
+extern void arch_unregister_hw_breakpoint(struct perf_event *bp);

Please no new 'extern'. In the old days 'extern' keyword was used, but 
new code shall not introduce new unnecessary usage of 'extern' keyword. 
See report from Checkpatch below:

WARNING:COMMIT_LOG_LONG_LINE: Possible unwrapped commit description 
(prefer a maximum 75 chars per line)
#9:
[1]: 
https://lore.kernel.org/linuxppc-dev/202005192233.oi9CjRtA%25lkp@intel.com/ (local)

CHECK:AVOID_EXTERNS: extern prototypes should be avoided in .h files
#40: FILE: include/linux/hw_breakpoint.h:83:
+extern int hw_breakpoint_weight(struct perf_event *bp);

I fixed it up when applying.

cheers