diff options
| author |   Johan Almbladh <johan.almbladh@anyfinetworks.com> | 2026-09-23 12:51:57 +0200 |
|---|---|---|
| committer |   Alexei Starovoitov <ast@kernel.org> | 2026-09-24 01:57:48 +0000 |
| commit | db762fd96be225bd06161c9631160c755d891693 (patch) | |
| tree | 9f987a92587cc2804b3ed7ac209dba235cfcb0ae | |
| parent | bpf: Reject dev-bound-only programs on other devices (diff) | |
bpf: Fix immediate JMP JEQ/JNE on MIPS32
An addu instruction was emitted instead of addiu, causing the immediate
value 1 to be interpreted as register $at. This made the comparison
result invalid when the immediate operand was negative. Note that $at
is mapped to BPF_REG_AX, which is used for constant blinding.
Fix the instruction to use the immediate form.
Found with test_bpf on MIPS32r1 emulated by QEMU.
Fixes: eb63cfcd2ee8 ("mips, bpf: Add eBPF JIT for 32-bit MIPS")
Signed-off-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://patch.msgid.link/20260923105158.3514342-1-johan.almbladh@anyfinetworks.com
| -rw-r--r-- | arch/mips/net/bpf_jit_comp32.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/mips/net/bpf_jit_comp32.c b/arch/mips/net/bpf_jit_comp32.c index 40a878b672f5..15a2a153dc87 100644 --- a/arch/mips/net/bpf_jit_comp32.c +++ b/arch/mips/net/bpf_jit_comp32.c @@ -1111,7 +1111,7 @@ static void emit_jmp_i64(struct jit_context *ctx, emit(ctx, xor, tmp, lo(dst), tmp); } if (imm < 0) { /* Compare sign extension */ - emit(ctx, addu, MIPS_R_T9, hi(dst), 1); + emit(ctx, addiu, MIPS_R_T9, hi(dst), 1); emit(ctx, or, tmp, tmp, MIPS_R_T9); } else { /* Compare zero extension */ emit(ctx, or, tmp, tmp, hi(dst)); |