This is a note to let you know that I've just added the patch titled
perf/x86: Shut up false-positive -Wmaybe-uninitialized warning
to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: perf-x86-shut-up-false-positive-wmaybe-uninitialized-warning.patch and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From 11d8b05855f3749bcb6c57e2c4052921b9605c77 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann arnd@arndb.de Date: Wed, 19 Jul 2017 14:52:59 +0200 Subject: perf/x86: Shut up false-positive -Wmaybe-uninitialized warning MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit
From: Arnd Bergmann arnd@arndb.de
commit 11d8b05855f3749bcb6c57e2c4052921b9605c77 upstream.
The intialization function checks for various failure scenarios, but unfortunately the compiler gets a little confused about the possible combinations, leading to a false-positive build warning when -Wmaybe-uninitialized is set:
arch/x86/events/core.c: In function ‘init_hw_perf_events’: arch/x86/events/core.c:264:3: warning: ‘reg_fail’ may be used uninitialized in this function [-Wmaybe-uninitialized] arch/x86/events/core.c:264:3: warning: ‘val_fail’ may be used uninitialized in this function [-Wmaybe-uninitialized] pr_err(FW_BUG "the BIOS has corrupted hw-PMU resources (MSR %x is %Lx)\n",
We can't actually run into this case, so this shuts up the warning by initializing the variables to a known-invalid state.
Suggested-by: Peter Zijlstra peterz@infradead.org Signed-off-by: Arnd Bergmann arnd@arndb.de Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Andy Lutomirski luto@kernel.org Cc: Arnaldo Carvalho de Melo acme@kernel.org Cc: Josh Poimboeuf jpoimboe@redhat.com Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Thomas Gleixner tglx@linutronix.de Link: http://lkml.kernel.org/r/20170719125310.2487451-2-arnd@arndb.de Link: https://patchwork.kernel.org/patch/9392595/ Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/events/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/x86/events/core.c +++ b/arch/x86/events/core.c @@ -190,8 +190,8 @@ static void release_pmc_hardware(void) {
static bool check_hw_exists(void) { - u64 val, val_fail, val_new= ~0; - int i, reg, reg_fail, ret = 0; + u64 val, val_fail = -1, val_new= ~0; + int i, reg, reg_fail = -1, ret = 0; int bios_fail = 0; int reg_safe = -1;
Patches currently in stable-queue which might be from arnd@arndb.de are
queue-4.9/kasan-rework-kconfig-settings.patch queue-4.9/tw5864-use-dev_warn-instead-of-warn-to-shut-up-warning.patch queue-4.9/perf-x86-shut-up-false-positive-wmaybe-uninitialized-warning.patch queue-4.9/go7007-add-media_camera_support-dependency.patch queue-4.9/scsi-advansys-fix-build-warning-for-pci-n.patch queue-4.9/video-fbdev-via-remove-possibly-unused-variables.patch queue-4.9/drm-exynos-mark-pm-functions-as-__maybe_unused.patch queue-4.9/binfmt_elf-compat-avoid-unused-function-warning.patch queue-4.9/idle-i7300-add-pci-dependency.patch queue-4.9/cw1200-fix-bogus-maybe-uninitialized-warning.patch queue-4.9/x86-build-silence-the-build-with-make-s.patch queue-4.9/gpio-xgene-mark-pm-functions-as-__maybe_unused.patch queue-4.9/kvm-add-x86_local_apic-dependency.patch queue-4.9/reiserfs-avoid-a-wmaybe-uninitialized-warning.patch queue-4.9/scsi-advansys-fix-uninitialized-data-access.patch queue-4.9/drm-i915-fix-intel_backlight_device_register-declaration.patch queue-4.9/spi-bcm-qspi-shut-up-warning-about-cfi-header-inclusion.patch queue-4.9/asoc-ux500-add-module_license-tag.patch queue-4.9/x86-microcode-amd-change-load_microcode_amd-s-param-to-bool-to-fix-preemptibility-bug.patch queue-4.9/video-fbdev-mmp-add-module_license.patch queue-4.9/usb-phy-msm-add-regulator-dependency.patch queue-4.9/arm64-dts-add-cooling-cells-to-cpu-nodes.patch queue-4.9/vmxnet3-prevent-building-with-64k-pages.patch queue-4.9/x86-platform-add-pci-dependency-for-punit_atom_debug.patch queue-4.9/alsa-hda-ca0132-fix-possible-null-pointer-use.patch queue-4.9/thermal-fix-intel_soc_dts_iosf_core-dependencies.patch queue-4.9/arm64-define-bug-instruction-without-config_bug.patch queue-4.9/arm64-sunxi-always-enable-reset-controller.patch queue-4.9/tc358743-fix-register-i2c_rd-wr-functions.patch queue-4.9/security-keys-big_key-requires-config_crypto.patch queue-4.9/drm-i915-hide-unused-intel_panel_set_backlight-function.patch queue-4.9/x86-fpu-math-emu-fix-possible-uninitialized-variable-use.patch queue-4.9/arm-8743-1-bl_switcher-add-module_license-tag.patch queue-4.9/em28xx-only-use-mt9v011-if-camera-support-is-enabled.patch queue-4.9/arm64-fix-warning-about-swapper_pg_dir-overflow.patch queue-4.9/shmem-avoid-maybe-uninitialized-warning.patch queue-4.9/input-tca8418_keypad-hide-gcc-4.9-wmaybe-uninitialized-warning.patch queue-4.9/drm-nouveau-hide-gcc-4.9-wmaybe-uninitialized.patch queue-4.9/x86-add-multiuser-dependency-for-kvm.patch queue-4.9/isdn-eicon-reduce-stack-size-of-sig_ind-function.patch