* include/linux/bitmap.h:820:20: warning: 'bitmap[0]' is used uninitialized
@ 2025-12-06 18:43 kernel test robot
0 siblings, 0 replies; only message in thread
From: kernel test robot @ 2025-12-06 18:43 UTC (permalink / raw)
To: Claudiu Beznea
Cc: oe-kbuild-all, linux-kernel, Bjorn Helgaas, Manivannan Sadhasivam
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: f468cf53c5240bf5063d0c6fe620b5ae2de37801
commit: 7ef502fb35b283e0f85ed7b34e2d963343981a8c PCI: Add Renesas RZ/G3S host controller driver
date: 11 days ago
config: riscv-randconfig-001-20251207 (https://download.01.org/0day-ci/archive/20251207/202512070218.XVMUQCl7-lkp@intel.com/config)
compiler: riscv64-linux-gcc (GCC) 13.4.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251207/202512070218.XVMUQCl7-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/202512070218.XVMUQCl7-lkp@intel.com/
All warnings (new ones prefixed by >>):
In file included from drivers/pci/controller/pcie-rzg3s-host.c:13:
In function 'bitmap_write',
inlined from 'rzg3s_pcie_msi_irq.part.0' at drivers/pci/controller/pcie-rzg3s-host.c:501:3:
>> include/linux/bitmap.h:820:20: warning: 'bitmap[0]' is used uninitialized [-Wuninitialized]
820 | map[index] &= (fit ? (~(mask << offset)) : ~BITMAP_FIRST_WORD_MASK(start));
| ^~
In file included from include/linux/kasan-checks.h:5,
from include/asm-generic/rwonce.h:26,
from ./arch/riscv/include/generated/asm/rwonce.h:1,
from include/linux/compiler.h:382,
from include/linux/build_bug.h:5,
from include/linux/bitfield.h:10,
from drivers/pci/controller/pcie-rzg3s-host.c:12:
drivers/pci/controller/pcie-rzg3s-host.c: In function 'rzg3s_pcie_msi_irq.part.0':
drivers/pci/controller/pcie-rzg3s-host.c:482:24: note: 'bitmap[0]' was declared here
482 | DECLARE_BITMAP(bitmap, RZG3S_PCI_MSI_INT_NR);
| ^~~~~~
include/linux/types.h:11:23: note: in definition of macro 'DECLARE_BITMAP'
11 | unsigned long name[BITS_TO_LONGS(bits)]
| ^~~~
Kconfig warnings: (for reference only)
WARNING: unmet direct dependencies detected for ARCH_HAS_ELF_CORE_EFLAGS
Depends on [n]: BINFMT_ELF [=y] && ELF_CORE [=n]
Selected by [y]:
- RISCV [=y]
vim +820 include/linux/bitmap.h
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 784
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 785 /**
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 786 * bitmap_write - write n-bit value within a memory region
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 787 * @map: address to the bitmap memory region
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 788 * @value: value to write, clamped to nbits
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 789 * @start: bit offset of the n-bit value
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 790 * @nbits: size of value in bits, nonzero, up to BITS_PER_LONG.
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 791 *
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 792 * bitmap_write() behaves as-if implemented as @nbits calls of __assign_bit(),
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 793 * i.e. bits beyond @nbits are ignored:
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 794 *
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 795 * for (bit = 0; bit < nbits; bit++)
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 796 * __assign_bit(start + bit, bitmap, val & BIT(bit));
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 797 *
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 798 * For @nbits == 0 and @nbits > BITS_PER_LONG no writes are performed.
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 799 */
ed8cd2b3bd9f070 Yury Norov 2024-07-18 800 static __always_inline
ed8cd2b3bd9f070 Yury Norov 2024-07-18 801 void bitmap_write(unsigned long *map, unsigned long value,
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 802 unsigned long start, unsigned long nbits)
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 803 {
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 804 size_t index;
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 805 unsigned long offset;
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 806 unsigned long space;
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 807 unsigned long mask;
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 808 bool fit;
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 809
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 810 if (unlikely(!nbits || nbits > BITS_PER_LONG))
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 811 return;
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 812
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 813 mask = BITMAP_LAST_WORD_MASK(nbits);
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 814 value &= mask;
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 815 offset = start % BITS_PER_LONG;
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 816 space = BITS_PER_LONG - offset;
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 817 fit = space >= nbits;
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 818 index = BIT_WORD(start);
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 819
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 @820 map[index] &= (fit ? (~(mask << offset)) : ~BITMAP_FIRST_WORD_MASK(start));
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 821 map[index] |= value << offset;
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 822 if (fit)
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 823 return;
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 824
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 825 map[index + 1] &= BITMAP_FIRST_WORD_MASK(start + nbits);
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 826 map[index + 1] |= (value >> space);
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 827 }
63c15822b8dd02a Syed Nayyar Waris 2024-03-27 828
:::::: The code at line 820 was first introduced by commit
:::::: 63c15822b8dd02a2423cfd92232245ace3f7a11b lib/bitmap: add bitmap_{read,write}()
:::::: TO: Syed Nayyar Waris <syednwaris@gmail.com>
:::::: CC: David S. Miller <davem@davemloft.net>
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
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