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Diffstat (limited to 'arch/arm/net/bpf_jit_32.c')
-rw-r--r--arch/arm/net/bpf_jit_32.c52
1 files changed, 34 insertions, 18 deletions
diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c
index cc29869d12a3..bf85d6db4931 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);
@@ -992,21 +1000,35 @@ static inline void emit_a32_mul_r64(const s8 dst[], const s8 src[],
arm_bpf_put_reg32(dst_hi, rd[0], ctx);
}
+static bool is_ldst_imm(s16 off, const u8 size)
+{
+ s16 off_max = 0;
+
+ switch (size) {
+ case BPF_B:
+ case BPF_W:
+ off_max = 0xfff;
+ break;
+ case BPF_H:
+ off_max = 0xff;
+ break;
+ case BPF_DW:
+ /* Need to make sure off+4 does not overflow. */
+ off_max = 0xfff - 4;
+ break;
+ }
+ return -off_max <= off && off <= off_max;
+}
+
/* *(size *)(dst + off) = src */
static inline void emit_str_r(const s8 dst, const s8 src[],
- s32 off, struct jit_ctx *ctx, const u8 sz){
+ s16 off, struct jit_ctx *ctx, const u8 sz){
const s8 *tmp = bpf2a32[TMP_REG_1];
- s32 off_max;
s8 rd;
rd = arm_bpf_get_reg32(dst, tmp[1], ctx);
- if (sz == BPF_H)
- off_max = 0xff;
- else
- off_max = 0xfff;
-
- if (off < 0 || off > off_max) {
+ if (!is_ldst_imm(off, sz)) {
emit_a32_mov_i(tmp[0], off, ctx);
emit(ARM_ADD_R(tmp[0], tmp[0], rd), ctx);
rd = tmp[0];
@@ -1035,18 +1057,12 @@ static inline void emit_str_r(const s8 dst, const s8 src[],
/* dst = *(size*)(src + off) */
static inline void emit_ldx_r(const s8 dst[], const s8 src,
- s32 off, struct jit_ctx *ctx, const u8 sz){
+ s16 off, struct jit_ctx *ctx, const u8 sz){
const s8 *tmp = bpf2a32[TMP_REG_1];
const s8 *rd = is_stacked(dst_lo) ? tmp : dst;
s8 rm = src;
- s32 off_max;
-
- if (sz == BPF_H)
- off_max = 0xff;
- else
- off_max = 0xfff;
- if (off < 0 || off > off_max) {
+ if (!is_ldst_imm(off, sz)) {
emit_a32_mov_i(tmp[0], off, ctx);
emit(ARM_ADD_R(tmp[0], tmp[0], src), ctx);
rm = tmp[0];