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Diffstat (limited to 'arch/arm/net/bpf_jit_32.c')
-rw-r--r--arch/arm/net/bpf_jit_32.c56
1 files changed, 43 insertions, 13 deletions
diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c
index 1d672457d0..72b5cd697f 100644
--- a/arch/arm/net/bpf_jit_32.c
+++ b/arch/arm/net/bpf_jit_32.c
@@ -871,16 +871,11 @@ static inline void emit_a32_alu_r64(const bool is64, const s8 dst[],
}
/* dst = src (4 bytes)*/
-static inline void emit_a32_mov_r(const s8 dst, const s8 src, const u8 off,
- struct jit_ctx *ctx) {
+static inline void emit_a32_mov_r(const s8 dst, const s8 src, struct jit_ctx *ctx) {
const s8 *tmp = bpf2a32[TMP_REG_1];
s8 rt;
rt = arm_bpf_get_reg32(src, tmp[0], ctx);
- if (off && off != 32) {
- emit(ARM_LSL_I(rt, rt, 32 - off), ctx);
- emit(ARM_ASR_I(rt, rt, 32 - off), ctx);
- }
arm_bpf_put_reg32(dst, rt, ctx);
}
@@ -889,15 +884,15 @@ static inline void emit_a32_mov_r64(const bool is64, const s8 dst[],
const s8 src[],
struct jit_ctx *ctx) {
if (!is64) {
- emit_a32_mov_r(dst_lo, src_lo, 0, ctx);
+ emit_a32_mov_r(dst_lo, src_lo, ctx);
if (!ctx->prog->aux->verifier_zext)
/* Zero out high 4 bytes */
emit_a32_mov_i(dst_hi, 0, ctx);
} else if (__LINUX_ARM_ARCH__ < 6 &&
ctx->cpu_architecture < CPU_ARCH_ARMv5TE) {
/* complete 8 byte move */
- emit_a32_mov_r(dst_lo, src_lo, 0, ctx);
- emit_a32_mov_r(dst_hi, src_hi, 0, ctx);
+ emit_a32_mov_r(dst_lo, src_lo, ctx);
+ emit_a32_mov_r(dst_hi, src_hi, ctx);
} else if (is_stacked(src_lo) && is_stacked(dst_lo)) {
const u8 *tmp = bpf2a32[TMP_REG_1];
@@ -917,17 +912,52 @@ static inline void emit_a32_mov_r64(const bool is64, const s8 dst[],
static inline void emit_a32_movsx_r64(const bool is64, const u8 off, const s8 dst[], const s8 src[],
struct jit_ctx *ctx) {
const s8 *tmp = bpf2a32[TMP_REG_1];
- const s8 *rt;
+ s8 rs;
+ s8 rd;
- rt = arm_bpf_get_reg64(dst, tmp, ctx);
+ if (is_stacked(dst_lo))
+ rd = tmp[1];
+ else
+ rd = dst_lo;
+ rs = arm_bpf_get_reg32(src_lo, rd, ctx);
+ /* rs may be one of src[1], dst[1], or tmp[1] */
+
+ /* Sign extend rs if needed. If off == 32, lower 32-bits of src are moved to dst and sign
+ * extension only happens in the upper 64 bits.
+ */
+ if (off != 32) {
+ /* Sign extend rs into rd */
+ emit(ARM_LSL_I(rd, rs, 32 - off), ctx);
+ emit(ARM_ASR_I(rd, rd, 32 - off), ctx);
+ } else {
+ rd = rs;
+ }
+
+ /* Write rd to dst_lo
+ *
+ * Optimization:
+ * Assume:
+ * 1. dst == src and stacked.
+ * 2. off == 32
+ *
+ * In this case src_lo was loaded into rd(tmp[1]) but rd was not sign extended as off==32.
+ * So, we don't need to write rd back to dst_lo as they have the same value.
+ * This saves us one str instruction.
+ */
+ if (dst_lo != src_lo || off != 32)
+ arm_bpf_put_reg32(dst_lo, rd, ctx);
- emit_a32_mov_r(dst_lo, src_lo, off, ctx);
if (!is64) {
if (!ctx->prog->aux->verifier_zext)
/* Zero out high 4 bytes */
emit_a32_mov_i(dst_hi, 0, ctx);
} else {
- emit(ARM_ASR_I(rt[0], rt[1], 31), ctx);
+ if (is_stacked(dst_hi)) {
+ emit(ARM_ASR_I(tmp[0], rd, 31), ctx);
+ arm_bpf_put_reg32(dst_hi, tmp[0], ctx);
+ } else {
+ emit(ARM_ASR_I(dst_hi, rd, 31), ctx);
+ }
}
}