From: kernel test robot <lkp@intel.com>
To: Sascha Bischoff <Sascha.Bischoff@arm.com>
Cc: llvm@lists.linux.dev, oe-kbuild-all@lists.linux.dev,
Oliver Upton <oliver.upton@linux.dev>,
Timothy Hayes <timothy.hayes@arm.com>
Subject: [linux-next:master 7731/9053] arch/arm64/kvm/vgic/vgic-mmio.c:1094:3: warning: variable 'len' is used uninitialized whenever 'if' condition is false
Date: Sun, 13 Jul 2025 03:29:42 +0800 [thread overview]
Message-ID: <202507130334.ddFcXn4N-lkp@intel.com> (raw)
tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head: a62b7a37e6fcf4a675b1548e7c168b96ec836442
commit: c017e49ed1381001ba7a6521daae8f968b11cf09 [7731/9053] KVM: arm64: gic-v5: Support GICv3 compat
config: arm64-randconfig-004-20250713 (https://download.01.org/0day-ci/archive/20250713/202507130334.ddFcXn4N-lkp@intel.com/config)
compiler: clang version 21.0.0git (https://github.com/llvm/llvm-project 01c97b4953e87ae455bd4c41e3de3f0f0f29c61c)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250713/202507130334.ddFcXn4N-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202507130334.ddFcXn4N-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> arch/arm64/kvm/vgic/vgic-mmio.c:1094:3: warning: variable 'len' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
1094 | BUG_ON(1);
| ^~~~~~~~~
include/asm-generic/bug.h:71:36: note: expanded from macro 'BUG_ON'
71 | #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
| ^~~~~~~~~~~~~~~~~~~
include/linux/compiler.h:47:23: note: expanded from macro 'unlikely'
47 | # define unlikely(x) (__branch_check__(x, 0, __builtin_constant_p(x)))
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/arm64/kvm/vgic/vgic-mmio.c:1102:12: note: uninitialized use occurs here
1102 | len, &io_device->dev);
| ^~~
arch/arm64/kvm/vgic/vgic-mmio.c:1094:3: note: remove the 'if' if its condition is always true
1094 | BUG_ON(1);
| ^
include/asm-generic/bug.h:71:32: note: expanded from macro 'BUG_ON'
71 | #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
| ^
arch/arm64/kvm/vgic/vgic-mmio.c:1084:18: note: initialize the variable 'len' to silence this warning
1084 | unsigned int len;
| ^
| = 0
1 warning generated.
vim +1094 arch/arm64/kvm/vgic/vgic-mmio.c
fb848db39661a1 virt/kvm/arm/vgic/vgic-mmio.c Andre Przywara 2016-04-26 1079
fb848db39661a1 virt/kvm/arm/vgic/vgic-mmio.c Andre Przywara 2016-04-26 1080 int vgic_register_dist_iodev(struct kvm *kvm, gpa_t dist_base_address,
fb848db39661a1 virt/kvm/arm/vgic/vgic-mmio.c Andre Przywara 2016-04-26 1081 enum vgic_type type)
fb848db39661a1 virt/kvm/arm/vgic/vgic-mmio.c Andre Przywara 2016-04-26 1082 {
fb848db39661a1 virt/kvm/arm/vgic/vgic-mmio.c Andre Przywara 2016-04-26 1083 struct vgic_io_device *io_device = &kvm->arch.vgic.dist_iodev;
fb848db39661a1 virt/kvm/arm/vgic/vgic-mmio.c Andre Przywara 2016-04-26 1084 unsigned int len;
fb848db39661a1 virt/kvm/arm/vgic/vgic-mmio.c Andre Przywara 2016-04-26 1085
fb848db39661a1 virt/kvm/arm/vgic/vgic-mmio.c Andre Przywara 2016-04-26 1086 switch (type) {
fb848db39661a1 virt/kvm/arm/vgic/vgic-mmio.c Andre Przywara 2016-04-26 1087 case VGIC_V2:
fb848db39661a1 virt/kvm/arm/vgic/vgic-mmio.c Andre Przywara 2016-04-26 1088 len = vgic_v2_init_dist_iodev(io_device);
fb848db39661a1 virt/kvm/arm/vgic/vgic-mmio.c Andre Przywara 2016-04-26 1089 break;
ed9b8cefa91695 virt/kvm/arm/vgic/vgic-mmio.c Andre Przywara 2015-12-01 1090 case VGIC_V3:
ed9b8cefa91695 virt/kvm/arm/vgic/vgic-mmio.c Andre Przywara 2015-12-01 1091 len = vgic_v3_init_dist_iodev(io_device);
ed9b8cefa91695 virt/kvm/arm/vgic/vgic-mmio.c Andre Przywara 2015-12-01 1092 break;
fb848db39661a1 virt/kvm/arm/vgic/vgic-mmio.c Andre Przywara 2016-04-26 1093 default:
fb848db39661a1 virt/kvm/arm/vgic/vgic-mmio.c Andre Przywara 2016-04-26 @1094 BUG_ON(1);
:::::: The code at line 1094 was first introduced by commit
:::::: fb848db39661a1243f6ae939ef7e9251a765b972 KVM: arm/arm64: vgic-new: Add GICv2 MMIO handling framework
:::::: TO: Andre Przywara <andre.przywara@arm.com>
:::::: CC: Christoffer Dall <christoffer.dall@linaro.org>
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
next reply other threads:[~2025-07-12 19:30 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-12 19:29 kernel test robot [this message]
2025-07-14 12:37 ` [linux-next:master 7731/9053] arch/arm64/kvm/vgic/vgic-mmio.c:1094:3: warning: variable 'len' is used uninitialized whenever 'if' condition is false Sascha Bischoff
2025-07-14 17:15 ` Nathan Chancellor
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