diff options
| author |   Brian Gerst <brgerst@gmail.com> | 2025-02-27 14:53:02 -0500 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2025-02-27 21:10:03 +0100 |
| commit | 18cdd90aba794333f4c6dce39f5c3fe642af5575 (patch) | |
| tree | fa261e4bc75e9ca189008817a18955535d17dce6 /kernel/bpf/verifier.c | |
| parent | x86/percpu: Disable named address spaces for UBSAN_BOOL with KASAN for GCC < 14.2 (diff) | |
| download | linux-rng-18cdd90aba794333f4c6dce39f5c3fe642af5575.tar.xz linux-rng-18cdd90aba794333f4c6dce39f5c3fe642af5575.zip | |
x86/bpf: Fix BPF percpu accesses
Due to this recent commit in the x86 tree:
9d7de2aa8b41 ("Use relative percpu offsets")
percpu addresses went from positive offsets from the GSBASE to negative
kernel virtual addresses. The BPF verifier has an optimization for
x86-64 that loads the address of cpu_number into a register, but was only
doing a 32-bit load which truncates negative addresses.
Change it to a 64-bit load so that the address is properly sign-extended.
Fixes: 9d7de2aa8b41 ("Use relative percpu offsets")
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250227195302.1667654-1-brgerst@gmail.com
Diffstat (limited to 'kernel/bpf/verifier.c')
| -rw-r--r-- | kernel/bpf/verifier.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 9971c03adfd5..f74263b206e4 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -21692,7 +21692,7 @@ patch_map_ops_generic: * way, it's fine to back out this inlining logic */ #ifdef CONFIG_SMP - insn_buf[0] = BPF_MOV32_IMM(BPF_REG_0, (u32)(unsigned long)&pcpu_hot.cpu_number); + insn_buf[0] = BPF_MOV64_IMM(BPF_REG_0, (u32)(unsigned long)&pcpu_hot.cpu_number); insn_buf[1] = BPF_MOV64_PERCPU_REG(BPF_REG_0, BPF_REG_0); insn_buf[2] = BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_0, 0); cnt = 3; |