ARM: net: bpf: avoid 'bx' instruction on non-Thumb capable CPUs (e9062481) · Commits · 戴 / test

arch/arm/net/bpf_jit_32.c

+11 −7

Original line number	Diff line number	Diff line
		@@ -285,16 +285,20 @@ static inline void emit_mov_i(const u8 rd, u32 val, struct jit_ctx *ctx)
		emit_mov_i_no8m(rd, val, ctx);
		}

		static inline void emit_blx_r(u8 tgt_reg, struct jit_ctx *ctx)
		static void emit_bx_r(u8 tgt_reg, struct jit_ctx *ctx)
		{
		ctx->seen \|= SEEN_CALL;
		#if __LINUX_ARM_ARCH__ < 5
		emit(ARM_MOV_R(ARM_LR, ARM_PC), ctx);

		if (elf_hwcap & HWCAP_THUMB)
		emit(ARM_BX(tgt_reg), ctx);
		else
		emit(ARM_MOV_R(ARM_PC, tgt_reg), ctx);
		}

		static inline void emit_blx_r(u8 tgt_reg, struct jit_ctx *ctx)
		{
		ctx->seen \|= SEEN_CALL;
		#if __LINUX_ARM_ARCH__ < 5
		emit(ARM_MOV_R(ARM_LR, ARM_PC), ctx);
		emit_bx_r(tgt_reg, ctx);
		#else
		emit(ARM_BLX_R(tgt_reg), ctx);
		#endif
		@@ -997,7 +1001,7 @@ static int emit_bpf_tail_call(struct jit_ctx *ctx)
		emit_a32_mov_i(tmp2[1], off, false, ctx);
		emit(ARM_LDR_R(tmp[1], tmp[1], tmp2[1]), ctx);
		emit(ARM_ADD_I(tmp[1], tmp[1], ctx->prologue_bytes), ctx);
		emit(ARM_BX(tmp[1]), ctx);
		emit_bx_r(tmp[1], ctx);

		/* out: */
		if (out_offset == -1)
		@@ -1166,7 +1170,7 @@ static void build_epilogue(struct jit_ctx *ctx)
		emit(ARM_POP(reg_set), ctx);
		/* Return back to the callee function */
		if (!(ctx->seen & SEEN_CALL))
		emit(ARM_BX(ARM_LR), ctx);
		emit_bx_r(ARM_LR, ctx);
		#endif
		}