linux/tools
Daniel Bristot de Oliveira 64dc40f752 tools/rtla: Fix uninitialized bucket/data->bucket_size warning
When compiling rtla with clang, I am getting the following warnings:

$ make HOSTCC=clang CC=clang LLVM_IAS=1

[..]
clang -O -g -DVERSION=\"6.8.0-rc3\" -flto=auto -fexceptions
	-fstack-protector-strong -fasynchronous-unwind-tables
	-fstack-clash-protection  -Wall -Werror=format-security
	-Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS
	$(pkg-config --cflags libtracefs)
	-c -o src/osnoise_hist.o src/osnoise_hist.c
src/osnoise_hist.c:138:6: warning: variable 'bucket' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
  138 |         if (data->bucket_size)
      |             ^~~~~~~~~~~~~~~~~
src/osnoise_hist.c:149:6: note: uninitialized use occurs here
  149 |         if (bucket < entries)
      |             ^~~~~~
src/osnoise_hist.c:138:2: note: remove the 'if' if its condition is always true
  138 |         if (data->bucket_size)
      |         ^~~~~~~~~~~~~~~~~~~~~~
  139 |                 bucket = duration / data->bucket_size;
src/osnoise_hist.c:132:12: note: initialize the variable 'bucket' to silence this warning
  132 |         int bucket;
      |                   ^
      |                    = 0
1 warning generated.

[...]

clang -O -g -DVERSION=\"6.8.0-rc3\" -flto=auto -fexceptions
	-fstack-protector-strong -fasynchronous-unwind-tables
	-fstack-clash-protection  -Wall -Werror=format-security
	-Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS
	$(pkg-config --cflags libtracefs)
	-c -o src/timerlat_hist.o src/timerlat_hist.c
src/timerlat_hist.c:181:6: warning: variable 'bucket' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
  181 |         if (data->bucket_size)
      |             ^~~~~~~~~~~~~~~~~
src/timerlat_hist.c:204:6: note: uninitialized use occurs here
  204 |         if (bucket < entries)
      |             ^~~~~~
src/timerlat_hist.c:181:2: note: remove the 'if' if its condition is always true
  181 |         if (data->bucket_size)
      |         ^~~~~~~~~~~~~~~~~~~~~~
  182 |                 bucket = latency / data->bucket_size;
src/timerlat_hist.c:175:12: note: initialize the variable 'bucket' to silence this warning
  175 |         int bucket;
      |                   ^
      |                    = 0
1 warning generated.

This is a legit warning, but data->bucket_size is always > 0 (see
timerlat_hist_parse_args()), so the if is not necessary.

Remove the unneeded if (data->bucket_size) to avoid the warning.

Link: https://lkml.kernel.org/r/6e1b1665cd99042ae705b3e0fc410858c4c42346.1707217097.git.bristot@kernel.org

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Bill Wendling <morbo@google.com>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Donald Zickus <dzickus@redhat.com>
Fixes: 1eeb6328e8 ("rtla/timerlat: Add timerlat hist mode")
Fixes: 829a6c0b56 ("rtla/osnoise: Add the hist mode")
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
2024-02-12 09:56:22 +01:00
..
accounting
arch work around gcc bugs with 'asm goto' with outputs 2024-02-09 15:57:48 -08:00
bootconfig
bpf bpfilter: remove bpfilter 2024-01-04 10:23:10 -08:00
build perf cs-etm: Bump minimum OpenCSD version to ensure a bugfix is present 2023-11-27 10:21:27 -03:00
certs
cgroup samples: introduce new samples subdir for cgroup 2023-12-10 16:51:54 -08:00
counter tools/counter: Remove unneeded semicolon 2023-12-20 11:43:31 -05:00
crypto crypto: tcrypt - add script tcrypt_speed_compare.py 2023-12-29 11:25:55 +08:00
debugging
edid
firewire
firmware
gpio
hv hv/hv_kvp_daemon: Some small fixes for handling NM keyfiles 2023-11-10 23:27:46 +00:00
iio iio: add modifiers for A and B ultraviolet light 2023-12-04 13:57:24 +00:00
include work around gcc bugs with 'asm goto' with outputs 2024-02-09 15:57:48 -08:00
kvm/kvm_stat
laptop
leds
lib perf tools improvements and fixes for v6.8: 2024-01-19 14:25:23 -08:00
memory-model
mm tools/mm: update the usage output to be more organized 2023-10-18 14:34:19 -07:00
net/ynl tools/net/ynl-gen-rst: Remove extra indentation from generated docs 2023-12-18 14:39:44 -08:00
objtool Address a GCC-14 warning: there's no real bug, but indeed the calloc order doesn't match 2024-01-08 18:31:27 -08:00
pci
pcmcia
perf perf evlist: Fix evlist__new_default() for > 1 core PMU 2024-01-30 11:40:28 -03:00
power tools cpupower bench: Override CFLAGS assignments 2024-01-21 16:57:51 -07:00
rcu
scripts tools/build: Fix -s detection code in tools/scripts/Makefile.include 2023-10-18 15:29:47 -07:00
spi
testing 21 hotfixes. 12 are cc:stable and the remainder pertain to post-6.7 2024-02-10 15:28:07 -08:00
thermal tools/thermal/tmon: Fix compilation warning for wrong format 2024-01-02 09:33:19 +01:00
time
tracing tools/rtla: Fix uninitialized bucket/data->bucket_size warning 2024-02-12 09:56:22 +01:00
usb
verification verification/dot2k: Delete duplicate imports 2023-10-30 16:59:12 +01:00
virtio tools/virtio: Add dma sync api for virtio test 2023-10-16 05:32:23 -04:00
wmi
workqueue workqueue: Implement non-strict affinity scope for unbound workqueues 2023-08-07 15:57:25 -10:00
Makefile