Commit bbfddb90 authored by Huacai Chen's avatar Huacai Chen
Browse files

LoongArch: BPF: Avoid declare variables in switch-case 



Not all compilers support declare variables in switch-case, so move
declarations to the beginning of a function. Otherwise we may get such
build errors:

arch/loongarch/net/bpf_jit.c: In function ‘emit_atomic’:
arch/loongarch/net/bpf_jit.c:362:3: error: a label can only be part of a statement and a declaration is not a statement
   u8 r0 = regmap[BPF_REG_0];
   ^~
arch/loongarch/net/bpf_jit.c: In function ‘build_insn’:
arch/loongarch/net/bpf_jit.c:727:3: error: a label can only be part of a statement and a declaration is not a statement
   u8 t7 = -1;
   ^~
arch/loongarch/net/bpf_jit.c:778:3: error: a label can only be part of a statement and a declaration is not a statement
   int ret;
   ^~~
arch/loongarch/net/bpf_jit.c:779:3: error: expected expression before ‘u64’
   u64 func_addr;
   ^~~
arch/loongarch/net/bpf_jit.c:780:3: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
   bool func_addr_fixed;
   ^~~~
arch/loongarch/net/bpf_jit.c:784:11: error: ‘func_addr’ undeclared (first use in this function); did you mean ‘in_addr’?
          &func_addr, &func_addr_fixed);
           ^~~~~~~~~
           in_addr
arch/loongarch/net/bpf_jit.c:784:11: note: each undeclared identifier is reported only once for each function it appears in
arch/loongarch/net/bpf_jit.c:814:3: error: a label can only be part of a statement and a declaration is not a statement
   u64 imm64 = (u64)(insn + 1)->imm << 32 | (u32)insn->imm;
   ^~~

Signed-off-by: default avatarHuacai Chen <chenhuacai@loongson.cn>
parent 4805a13d

arch/loongarch/net/bpf_jit.c

+13 −18
Original line number Diff line number Diff line
@@ -279,6 +279,7 @@ static void emit_atomic(const struct bpf_insn *insn, struct jit_ctx *ctx) 
	const u8 t1 = LOONGARCH_GPR_T1;

	const u8 t2 = LOONGARCH_GPR_T2;

	const u8 t3 = LOONGARCH_GPR_T3;

	const u8 r0 = regmap[BPF_REG_0];

	const u8 src = regmap[insn->src_reg];

	const u8 dst = regmap[insn->dst_reg];

	const s16 off = insn->off;
@@ -359,8 +360,6 @@ static void emit_atomic(const struct bpf_insn *insn, struct jit_ctx *ctx) 
		break;

	/* r0 = atomic_cmpxchg(dst + off, r0, src); */

	case BPF_CMPXCHG:

		u8 r0 = regmap[BPF_REG_0];



		move_reg(ctx, t2, r0);

		if (isdw) {

			emit_insn(ctx, lld, r0, t1, 0);
@@ -390,8 +389,11 @@ static bool is_signed_bpf_cond(u8 cond) 


static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool extra_pass)

{

	const bool is32 = BPF_CLASS(insn->code) == BPF_ALU ||

			  BPF_CLASS(insn->code) == BPF_JMP32;

	u8 tm = -1;

	u64 func_addr;

	bool func_addr_fixed;

	int i = insn - ctx->prog->insnsi;

	int ret, jmp_offset;

	const u8 code = insn->code;

	const u8 cond = BPF_OP(code);

	const u8 t1 = LOONGARCH_GPR_T1;
@@ -400,8 +402,8 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext 
	const u8 dst = regmap[insn->dst_reg];

	const s16 off = insn->off;

	const s32 imm = insn->imm;

	int jmp_offset;

	int i = insn - ctx->prog->insnsi;

	const u64 imm64 = (u64)(insn + 1)->imm << 32 | (u32)insn->imm;

	const bool is32 = BPF_CLASS(insn->code) == BPF_ALU || BPF_CLASS(insn->code) == BPF_JMP32;



	switch (code) {

	/* dst = src */
@@ -724,24 +726,23 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext 
	case BPF_JMP32 | BPF_JSGE | BPF_K:

	case BPF_JMP32 | BPF_JSLT | BPF_K:

	case BPF_JMP32 | BPF_JSLE | BPF_K:

		u8 t7 = -1;

		jmp_offset = bpf2la_offset(i, off, ctx);

		if (imm) {

			move_imm(ctx, t1, imm, false);

			t7 = t1;

			tm = t1;

		} else {

			/* If imm is 0, simply use zero register. */

			t7 = LOONGARCH_GPR_ZERO;

			tm = LOONGARCH_GPR_ZERO;

		}

		move_reg(ctx, t2, dst);

		if (is_signed_bpf_cond(BPF_OP(code))) {

			emit_sext_32(ctx, t7, is32);

			emit_sext_32(ctx, tm, is32);

			emit_sext_32(ctx, t2, is32);

		} else {

			emit_zext_32(ctx, t7, is32);

			emit_zext_32(ctx, tm, is32);

			emit_zext_32(ctx, t2, is32);

		}

		if (emit_cond_jmp(ctx, cond, t2, t7, jmp_offset) < 0)

		if (emit_cond_jmp(ctx, cond, t2, tm, jmp_offset) < 0)

			goto toofar;

		break;
@@ -775,10 +776,6 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext 


	/* function call */

	case BPF_JMP | BPF_CALL:

		int ret;

		u64 func_addr;

		bool func_addr_fixed;



		mark_call(ctx);

		ret = bpf_jit_get_func_addr(ctx->prog, insn, extra_pass,

					    &func_addr, &func_addr_fixed);
@@ -811,8 +808,6 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext 


	/* dst = imm64 */

	case BPF_LD | BPF_IMM | BPF_DW:

		u64 imm64 = (u64)(insn + 1)->imm << 32 | (u32)insn->imm;



		move_imm(ctx, dst, imm64, is32);

		return 1;