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| author | Eduard Zingerman <eddyz87@gmail.com> | 2026-09-04 01:33:23 -0700 |
|---|---|---|
| committer | Kumar Kartikeya Dwivedi <memxor@gmail.com> | 2026-09-04 12:58:04 +0200 |
| commit | 836b2fe544a5e9b5ce116622cb36fba33838c6fd (patch) | |
| tree | 95e38e4aaa0a6a78e373148b3d0af4aa2ab3d371 /rust/helpers/atomic_ext.c | |
| download | linux-stable-836b2fe544a5e9b5ce116622cb36fba33838c6fd.tar.gz linux-stable-836b2fe544a5e9b5ce116622cb36fba33838c6fd.zip | |
selftests/bpf: Check that JMP32 pointer vs zero jumps are not predictedgrafted
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 <npc@anthropic.com>
Suggested-by: Nicholas Carlini <npc@anthropic.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20260904083325.2083493-6-eddyz87@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Diffstat (limited to 'rust/helpers/atomic_ext.c')
| -rw-r--r-- | rust/helpers/atomic_ext.c | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/rust/helpers/atomic_ext.c b/rust/helpers/atomic_ext.c new file mode 100644 index 000000000..c267d5190 --- /dev/null +++ b/rust/helpers/atomic_ext.c @@ -0,0 +1,87 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <asm/barrier.h> +#include <asm/rwonce.h> +#include <linux/atomic.h> + +#define GEN_READ_HELPER(tname, type) \ +__rust_helper type rust_helper_atomic_##tname##_read(type *ptr) \ +{ \ + return READ_ONCE(*ptr); \ +} + +#define GEN_SET_HELPER(tname, type) \ +__rust_helper void rust_helper_atomic_##tname##_set(type *ptr, type val) \ +{ \ + WRITE_ONCE(*ptr, val); \ +} + +#define GEN_READ_ACQUIRE_HELPER(tname, type) \ +__rust_helper type rust_helper_atomic_##tname##_read_acquire(type *ptr) \ +{ \ + return smp_load_acquire(ptr); \ +} + +#define GEN_SET_RELEASE_HELPER(tname, type) \ +__rust_helper void rust_helper_atomic_##tname##_set_release(type *ptr, type val)\ +{ \ + smp_store_release(ptr, val); \ +} + +#define GEN_READ_SET_HELPERS(tname, type) \ + GEN_READ_HELPER(tname, type) \ + GEN_SET_HELPER(tname, type) \ + GEN_READ_ACQUIRE_HELPER(tname, type) \ + GEN_SET_RELEASE_HELPER(tname, type) \ + +GEN_READ_SET_HELPERS(i8, s8) +GEN_READ_SET_HELPERS(i16, s16) +GEN_READ_SET_HELPERS(ptr, const void *) + +/* + * xchg helpers depend on ARCH_SUPPORTS_ATOMIC_RMW and on the + * architecture provding xchg() support for i8 and i16. + * + * The architectures that currently support Rust (x86_64, armv7, + * arm64, riscv, and loongarch) satisfy these requirements. + */ +#define GEN_XCHG_HELPER(tname, type, suffix) \ +__rust_helper type \ +rust_helper_atomic_##tname##_xchg##suffix(type *ptr, type new) \ +{ \ + return xchg##suffix(ptr, new); \ +} + +#define GEN_XCHG_HELPERS(tname, type) \ + GEN_XCHG_HELPER(tname, type, ) \ + GEN_XCHG_HELPER(tname, type, _acquire) \ + GEN_XCHG_HELPER(tname, type, _release) \ + GEN_XCHG_HELPER(tname, type, _relaxed) \ + +GEN_XCHG_HELPERS(i8, s8) +GEN_XCHG_HELPERS(i16, s16) +GEN_XCHG_HELPERS(ptr, const void *) + +/* + * try_cmpxchg helpers depend on ARCH_SUPPORTS_ATOMIC_RMW and on the + * architecture provding try_cmpxchg() support for i8 and i16. + * + * The architectures that currently support Rust (x86_64, armv7, + * arm64, riscv, and loongarch) satisfy these requirements. + */ +#define GEN_TRY_CMPXCHG_HELPER(tname, type, suffix) \ +__rust_helper bool \ +rust_helper_atomic_##tname##_try_cmpxchg##suffix(type *ptr, type *old, type new)\ +{ \ + return try_cmpxchg##suffix(ptr, old, new); \ +} + +#define GEN_TRY_CMPXCHG_HELPERS(tname, type) \ + GEN_TRY_CMPXCHG_HELPER(tname, type, ) \ + GEN_TRY_CMPXCHG_HELPER(tname, type, _acquire) \ + GEN_TRY_CMPXCHG_HELPER(tname, type, _release) \ + GEN_TRY_CMPXCHG_HELPER(tname, type, _relaxed) \ + +GEN_TRY_CMPXCHG_HELPERS(i8, s8) +GEN_TRY_CMPXCHG_HELPERS(i16, s16) +GEN_TRY_CMPXCHG_HELPERS(ptr, const void *) |