diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c index 97dc386e3cb8..cc288a1a7193 100644 --- a/arch/arm/net/bpf_jit_32.c +++ b/arch/arm/net/bpf_jit_32.c @@ -929,7 +929,11 @@ static inline void emit_a32_rsh_i64(const s8 dst[], rd = arm_bpf_get_reg64(dst, tmp, ctx); /* Do LSR operation */ - if (val < 32) { + if (val == 0) { + /* An immediate value of 0 encodes a shift amount of 32 + * for LSR. To shift by 0, don't do anything. + */ + } else if (val < 32) { emit(ARM_MOV_SI(tmp2[1], rd[1], SRTYPE_LSR, val), ctx); emit(ARM_ORR_SI(rd[1], tmp2[1], rd[0], SRTYPE_ASL, 32 - val), ctx); emit(ARM_MOV_SI(rd[0], rd[0], SRTYPE_LSR, val), ctx); @@ -955,7 +959,11 @@ static inline void emit_a32_arsh_i64(const s8 dst[], rd = arm_bpf_get_reg64(dst, tmp, ctx); /* Do ARSH operation */ - if (val < 32) { + if (val == 0) { + /* An immediate value of 0 encodes a shift amount of 32 + * for ASR. To shift by 0, don't do anything. + */ + } else if (val < 32) { emit(ARM_MOV_SI(tmp2[1], rd[1], SRTYPE_LSR, val), ctx); emit(ARM_ORR_SI(rd[1], tmp2[1], rd[0], SRTYPE_ASL, 32 - val), ctx); emit(ARM_MOV_SI(rd[0], rd[0], SRTYPE_ASR, val), ctx);