Merge branch 'maybe-uninitialized' (patches from Arnd)

Merge fixes for -Wmaybe-uninitialized from Arnd Bergmann:
 "It took a while for some patches to make it into mainline through
  maintainer trees, but the 28-patch series is now reduced to 10, with
  one tiny patch added at the end.

  Aside from patches that are no longer required, I did these changes
  compared to version 1:

   - Dropped "iio: maxim_thermocouple: detect invalid storage size in
     read()", which is currently in linux-next as commit 32cb7d27e65d.
     This is the only remaining warning I see for a couple of corner
     cases (kbuild bot reports it on blackfin, kernelci bot and arm-soc
     bot both report it on arm64)

   - Dropped "brcmfmac: avoid maybe-uninitialized warning in
     brcmf_cfg80211_start_ap", which is currently in net/master merge
     pending.

   - Dropped two x86 patches, "x86: math-emu: possible uninitialized
     variable use" and "x86: mark target address as output in 'insb'
     asm" as they do not seem to trigger for a default build, and I got
     no feedback on them. Both of these are ancient issues and seem
     harmless, I will send them again to the x86 maintainers once the
     rest is merged.

   - Dropped "rbd: false-postive gcc-4.9 -Wmaybe-uninitialized" based on
     feedback from Ilya Dryomov, who already has a different fix queued
     up for v4.10. The kbuild bot reports this as a warning for xtensa.

   - Replaced "crypto: aesni: avoid -Wmaybe-uninitialized warning" with
     a simpler patch, this one always triggers but my first solution
     would not be safe for linux-4.9 any more at this point. I'll follow
     up with the larger patch as a cleanup for 4.10.

   - Replaced "dib0700: fix nec repeat handling" with a better one,
     contributed by Sean Young"

* -Wmaybe-uninitialized fixes:
  Kbuild: enable -Wmaybe-uninitialized warnings by default
  pcmcia: fix return value of soc_pcmcia_regulator_set
  infiniband: shut up a maybe-uninitialized warning
  crypto: aesni: shut up -Wmaybe-uninitialized warning
  rc: print correct variable for z8f0811
  dib0700: fix nec repeat handling
  s390: pci: don't print uninitialized data for debugging
  nios2: fix timer initcall return value
  x86: apm: avoid uninitialized data
  NFSv4.1: work around -Wmaybe-uninitialized warning
  Kbuild: enable -Wmaybe-uninitialized warning for "make W=1"

2 files changed, 5 insertions, 0 deletions

diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn
index 53449a6ff6aa..7c321a603b07 100644
--- a/scripts/Makefile.extrawarn
+++ b/scripts/Makefile.extrawarn
@@ -36,6 +36,7 @@ warning-2 += -Wshadow
 warning-2 += $(call cc-option, -Wlogical-op)
 warning-2 += $(call cc-option, -Wmissing-field-initializers)
 warning-2 += $(call cc-option, -Wsign-compare)
+warning-2 += $(call cc-option, -Wmaybe-uninitialized)
 
 warning-3 := -Wbad-function-cast
 warning-3 += -Wcast-qual
diff --git a/scripts/Makefile.ubsan b/scripts/Makefile.ubsan
index dd779c40c8e6..3b1b13818d59 100644
--- a/scripts/Makefile.ubsan
+++ b/scripts/Makefile.ubsan
@@ -17,4 +17,8 @@ endif
 ifdef CONFIG_UBSAN_NULL
       CFLAGS_UBSAN += $(call cc-option, -fsanitize=null)
 endif
+
+      # -fsanitize=* options makes GCC less smart than usual and
+      # increase number of 'maybe-uninitialized false-positives
+      CFLAGS_UBSAN += $(call cc-option, -Wno-maybe-uninitialized)
 endif