Commit bb392867 authored by Alexei Starovoitov's avatar Alexei Starovoitov
Browse files

Merge branch 'ppc-fix' 



Daniel Borkmann says:

====================
This set adds a ppc64 JIT fix for xadd as well as a missing test
case for verifying whether xadd messes with src/dst reg. Thanks!
====================

Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parents f39f28ff fa47a16b

arch/powerpc/net/bpf_jit_comp64.c

+5 −24
Original line number Diff line number Diff line
@@ -286,6 +286,7 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, 
		u64 imm64;

		u8 *func;

		u32 true_cond;

		u32 tmp_idx;



		/*

		 * addrs[] maps a BPF bytecode address into a real offset from
@@ -637,11 +638,7 @@ emit_clear: 
		case BPF_STX | BPF_XADD | BPF_W:

			/* Get EA into TMP_REG_1 */

			PPC_ADDI(b2p[TMP_REG_1], dst_reg, off);

			/* error if EA is not word-aligned */

			PPC_ANDI(b2p[TMP_REG_2], b2p[TMP_REG_1], 0x03);

			PPC_BCC_SHORT(COND_EQ, (ctx->idx * 4) + 12);

			PPC_LI(b2p[BPF_REG_0], 0);

			PPC_JMP(exit_addr);

			tmp_idx = ctx->idx * 4;

			/* load value from memory into TMP_REG_2 */

			PPC_BPF_LWARX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1], 0);

			/* add value from src_reg into this */
@@ -649,32 +646,16 @@ emit_clear: 
			/* store result back */

			PPC_BPF_STWCX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1]);

			/* we're done if this succeeded */

			PPC_BCC_SHORT(COND_EQ, (ctx->idx * 4) + (7*4));

			/* otherwise, let's try once more */

			PPC_BPF_LWARX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1], 0);

			PPC_ADD(b2p[TMP_REG_2], b2p[TMP_REG_2], src_reg);

			PPC_BPF_STWCX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1]);

			/* exit if the store was not successful */

			PPC_LI(b2p[BPF_REG_0], 0);

			PPC_BCC(COND_NE, exit_addr);

			PPC_BCC_SHORT(COND_NE, tmp_idx);

			break;

		/* *(u64 *)(dst + off) += src */

		case BPF_STX | BPF_XADD | BPF_DW:

			PPC_ADDI(b2p[TMP_REG_1], dst_reg, off);

			/* error if EA is not doubleword-aligned */

			PPC_ANDI(b2p[TMP_REG_2], b2p[TMP_REG_1], 0x07);

			PPC_BCC_SHORT(COND_EQ, (ctx->idx * 4) + (3*4));

			PPC_LI(b2p[BPF_REG_0], 0);

			PPC_JMP(exit_addr);

			PPC_BPF_LDARX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1], 0);

			PPC_ADD(b2p[TMP_REG_2], b2p[TMP_REG_2], src_reg);

			PPC_BPF_STDCX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1]);

			PPC_BCC_SHORT(COND_EQ, (ctx->idx * 4) + (7*4));

			tmp_idx = ctx->idx * 4;

			PPC_BPF_LDARX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1], 0);

			PPC_ADD(b2p[TMP_REG_2], b2p[TMP_REG_2], src_reg);

			PPC_BPF_STDCX(b2p[TMP_REG_2], 0, b2p[TMP_REG_1]);

			PPC_LI(b2p[BPF_REG_0], 0);

			PPC_BCC(COND_NE, exit_addr);

			PPC_BCC_SHORT(COND_NE, tmp_idx);

			break;



		/*

tools/testing/selftests/bpf/test_verifier.c

+40 −0
Original line number Diff line number Diff line
@@ -12004,6 +12004,46 @@ static struct bpf_test tests[] = { 
		.errstr = "BPF_XADD stores into R2 packet",

		.prog_type = BPF_PROG_TYPE_XDP,

	},

	{

		"xadd/w check whether src/dst got mangled, 1",

		.insns = {

			BPF_MOV64_IMM(BPF_REG_0, 1),

			BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),

			BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),

			BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8),

			BPF_STX_XADD(BPF_DW, BPF_REG_10, BPF_REG_0, -8),

			BPF_STX_XADD(BPF_DW, BPF_REG_10, BPF_REG_0, -8),

			BPF_JMP_REG(BPF_JNE, BPF_REG_6, BPF_REG_0, 3),

			BPF_JMP_REG(BPF_JNE, BPF_REG_7, BPF_REG_10, 2),

			BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8),

			BPF_EXIT_INSN(),

			BPF_MOV64_IMM(BPF_REG_0, 42),

			BPF_EXIT_INSN(),

		},

		.result = ACCEPT,

		.prog_type = BPF_PROG_TYPE_SCHED_CLS,

		.retval = 3,

	},

	{

		"xadd/w check whether src/dst got mangled, 2",

		.insns = {

			BPF_MOV64_IMM(BPF_REG_0, 1),

			BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),

			BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),

			BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_0, -8),

			BPF_STX_XADD(BPF_W, BPF_REG_10, BPF_REG_0, -8),

			BPF_STX_XADD(BPF_W, BPF_REG_10, BPF_REG_0, -8),

			BPF_JMP_REG(BPF_JNE, BPF_REG_6, BPF_REG_0, 3),

			BPF_JMP_REG(BPF_JNE, BPF_REG_7, BPF_REG_10, 2),

			BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_10, -8),

			BPF_EXIT_INSN(),

			BPF_MOV64_IMM(BPF_REG_0, 42),

			BPF_EXIT_INSN(),

		},

		.result = ACCEPT,

		.prog_type = BPF_PROG_TYPE_SCHED_CLS,

		.retval = 3,

	},

	{

		"bpf_get_stack return R0 within range",

		.insns = {

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