This is a note to let you know that I've just added the patch titled
x86/fpu/math-emu: Fix possible uninitialized variable use
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-fpu-math-emu-fix-possible-uninitialized-variable-use.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@xxxxxxxxxxxxxxx> know about it.
>From 75e2f0a6b16141cb347f442033ec907380d4d66e Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@xxxxxxxx>
Date: Wed, 19 Jul 2017 14:53:00 +0200
Subject: x86/fpu/math-emu: Fix possible uninitialized variable use
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
From: Arnd Bergmann <arnd@xxxxxxxx>
commit 75e2f0a6b16141cb347f442033ec907380d4d66e upstream.
When building the kernel with "make EXTRA_CFLAGS=...", this overrides
the "PARANOID" preprocessor macro defined in arch/x86/math-emu/Makefile,
and we run into a build warning:
arch/x86/math-emu/reg_compare.c: In function ‘compare_i_st_st’:
arch/x86/math-emu/reg_compare.c:254:6: error: ‘f’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
This fixes the implementation to work correctly even without the PARANOID
flag, and also fixes the Makefile to not use the EXTRA_CFLAGS variable
but instead use the ccflags-y variable in the Makefile that is meant
for this purpose.
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Bill Metzenthen <billm@xxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20170719125310.2487451-3-arnd@xxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/math-emu/Makefile | 4 ++--
arch/x86/math-emu/reg_compare.c | 16 ++++++++--------
2 files changed, 10 insertions(+), 10 deletions(-)
--- a/arch/x86/math-emu/Makefile
+++ b/arch/x86/math-emu/Makefile
@@ -5,8 +5,8 @@
#DEBUG = -DDEBUGGING
DEBUG =
PARANOID = -DPARANOID
-EXTRA_CFLAGS := $(PARANOID) $(DEBUG) -fno-builtin $(MATH_EMULATION)
-EXTRA_AFLAGS := $(PARANOID)
+ccflags-y += $(PARANOID) $(DEBUG) -fno-builtin $(MATH_EMULATION)
+asflags-y += $(PARANOID)
# From 'C' language sources:
C_OBJS =fpu_entry.o errors.o \
--- a/arch/x86/math-emu/reg_compare.c
+++ b/arch/x86/math-emu/reg_compare.c
@@ -168,7 +168,7 @@ static int compare(FPU_REG const *b, int
/* This function requires that st(0) is not empty */
int FPU_compare_st_data(FPU_REG const *loaded_data, u_char loaded_tag)
{
- int f = 0, c;
+ int f, c;
c = compare(loaded_data, loaded_tag);
@@ -189,12 +189,12 @@ int FPU_compare_st_data(FPU_REG const *l
case COMP_No_Comp:
f = SW_C3 | SW_C2 | SW_C0;
break;
-#ifdef PARANOID
default:
+#ifdef PARANOID
EXCEPTION(EX_INTERNAL | 0x121);
+#endif /* PARANOID */
f = SW_C3 | SW_C2 | SW_C0;
break;
-#endif /* PARANOID */
}
setcc(f);
if (c & COMP_Denormal) {
@@ -205,7 +205,7 @@ int FPU_compare_st_data(FPU_REG const *l
static int compare_st_st(int nr)
{
- int f = 0, c;
+ int f, c;
FPU_REG *st_ptr;
if (!NOT_EMPTY(0) || !NOT_EMPTY(nr)) {
@@ -235,12 +235,12 @@ static int compare_st_st(int nr)
case COMP_No_Comp:
f = SW_C3 | SW_C2 | SW_C0;
break;
-#ifdef PARANOID
default:
+#ifdef PARANOID
EXCEPTION(EX_INTERNAL | 0x122);
+#endif /* PARANOID */
f = SW_C3 | SW_C2 | SW_C0;
break;
-#endif /* PARANOID */
}
setcc(f);
if (c & COMP_Denormal) {
@@ -283,12 +283,12 @@ static int compare_i_st_st(int nr)
case COMP_No_Comp:
f = X86_EFLAGS_ZF | X86_EFLAGS_PF | X86_EFLAGS_CF;
break;
-#ifdef PARANOID
default:
+#ifdef PARANOID
EXCEPTION(EX_INTERNAL | 0x122);
+#endif /* PARANOID */
f = 0;
break;
-#endif /* PARANOID */
}
FPU_EFLAGS = (FPU_EFLAGS & ~(X86_EFLAGS_ZF | X86_EFLAGS_PF | X86_EFLAGS_CF)) | f;
if (c & COMP_Denormal) {
Patches currently in stable-queue which might be from arnd@xxxxxxxx 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