This is a note to let you know that I've just added the patch titled
reiserfs: avoid a -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: reiserfs-avoid-a-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 ab4949640d6674b617b314ad3c2c00353304bab9 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann arnd@arndb.de Date: Thu, 23 Mar 2017 16:06:13 +0100 Subject: reiserfs: avoid a -Wmaybe-uninitialized warning
From: Arnd Bergmann arnd@arndb.de
commit ab4949640d6674b617b314ad3c2c00353304bab9 upstream.
The latest gcc-7.0.1 snapshot warns about an unintialized variable use:
In file included from fs/reiserfs/lbalance.c:8:0: fs/reiserfs/lbalance.c: In function 'leaf_item_bottle.isra.3': fs/reiserfs/reiserfs.h:1279:13: error: '*((void *)&n_ih+8).v' may be used uninitialized in this function [-Werror=maybe-uninitialized] v2->v = (v2->v & cpu_to_le64(15ULL << 60)) | cpu_to_le64(offset); ~~^~~ fs/reiserfs/reiserfs.h:1279:13: error: '*((void *)&n_ih+8).v' may be used uninitialized in this function [-Werror=maybe-uninitialized] v2->v = (v2->v & cpu_to_le64(15ULL << 60)) | cpu_to_le64(offset);
This happens because the offset/type pair that is stored in ih.key.u.k_offset_v2 is actually uninitialized when we call set_le_ih_k_offset() and set_le_ih_k_type(). After we have called both, all data is correct, but the first of the two reads uninitialized data for the type field and writes it back before it gets overwritten.
This works around the warning by initializing the k_offset_v2 through the slightly larger memcpy().
[JK: Remove now unused define and make it obvious we initialize the key]
Signed-off-by: Arnd Bergmann arnd@arndb.de Signed-off-by: Jan Kara jack@suse.cz Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/reiserfs/lbalance.c | 2 +- fs/reiserfs/reiserfs.h | 1 - 2 files changed, 1 insertion(+), 2 deletions(-)
--- a/fs/reiserfs/lbalance.c +++ b/fs/reiserfs/lbalance.c @@ -475,7 +475,7 @@ static void leaf_item_bottle(struct buff * 'cpy_bytes'; create new item header; * n_ih = new item_header; */ - memcpy(&n_ih, ih, SHORT_KEY_SIZE); + memcpy(&n_ih.ih_key, &ih->ih_key, KEY_SIZE);
/* Endian safe, both le */ n_ih.ih_version = ih->ih_version; --- a/fs/reiserfs/reiserfs.h +++ b/fs/reiserfs/reiserfs.h @@ -1326,7 +1326,6 @@ struct cpu_key { #define KEY_NOT_FOUND 0
#define KEY_SIZE (sizeof(struct reiserfs_key)) -#define SHORT_KEY_SIZE (sizeof (__u32) + sizeof (__u32))
/* return values for search_by_key and clones */ #define ITEM_FOUND 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