From 836b2fe544a5e9b5ce116622cb36fba33838c6fd Mon Sep 17 00:00:00 2001 From: Eduard Zingerman Date: Fri, 4 Sep 2026 01:33:23 -0700 Subject: selftests/bpf: Check that JMP32 pointer vs zero jumps are not predicted Add jmp32_ptr_vs_zero_jne: the fall-through of the 32-bit compare, which the verifier used to skip, contains an out of bounds map value access, hence w/o the previous patch the program is accepted. See previous patch for detailed description. Reported-by: Nicholas Carlini Suggested-by: Nicholas Carlini Signed-off-by: Eduard Zingerman Link: https://lore.kernel.org/bpf/20260904083325.2083493-6-eddyz87@gmail.com Signed-off-by: Kumar Kartikeya Dwivedi --- include/asm-generic/bitops/atomic.h | 70 +++++++++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) create mode 100644 include/asm-generic/bitops/atomic.h (limited to 'include/asm-generic/bitops/atomic.h') diff --git a/include/asm-generic/bitops/atomic.h b/include/asm-generic/bitops/atomic.h new file mode 100644 index 000000000..e076e079f --- /dev/null +++ b/include/asm-generic/bitops/atomic.h @@ -0,0 +1,70 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_ATOMIC_H_ +#define _ASM_GENERIC_BITOPS_ATOMIC_H_ + +#include +#include +#include + +/* + * Implementation of atomic bitops using atomic-fetch ops. + * See Documentation/atomic_bitops.txt for details. + */ + +static __always_inline void +arch_set_bit(unsigned int nr, volatile unsigned long *p) +{ + p += BIT_WORD(nr); + raw_atomic_long_or(BIT_MASK(nr), (atomic_long_t *)p); +} + +static __always_inline void +arch_clear_bit(unsigned int nr, volatile unsigned long *p) +{ + p += BIT_WORD(nr); + raw_atomic_long_andnot(BIT_MASK(nr), (atomic_long_t *)p); +} + +static __always_inline void +arch_change_bit(unsigned int nr, volatile unsigned long *p) +{ + p += BIT_WORD(nr); + raw_atomic_long_xor(BIT_MASK(nr), (atomic_long_t *)p); +} + +static __always_inline int +arch_test_and_set_bit(unsigned int nr, volatile unsigned long *p) +{ + long old; + unsigned long mask = BIT_MASK(nr); + + p += BIT_WORD(nr); + old = raw_atomic_long_fetch_or(mask, (atomic_long_t *)p); + return !!(old & mask); +} + +static __always_inline int +arch_test_and_clear_bit(unsigned int nr, volatile unsigned long *p) +{ + long old; + unsigned long mask = BIT_MASK(nr); + + p += BIT_WORD(nr); + old = raw_atomic_long_fetch_andnot(mask, (atomic_long_t *)p); + return !!(old & mask); +} + +static __always_inline int +arch_test_and_change_bit(unsigned int nr, volatile unsigned long *p) +{ + long old; + unsigned long mask = BIT_MASK(nr); + + p += BIT_WORD(nr); + old = raw_atomic_long_fetch_xor(mask, (atomic_long_t *)p); + return !!(old & mask); +} + +#include + +#endif /* _ASM_GENERIC_BITOPS_ATOMIC_H */ -- cgit v1.3.1