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Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 

Daniel Borkmann says:

====================
pull-request: bpf 2018-07-20

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) Fix in BPF Makefile to detect llvm-objcopy in a more robust way which is
   needed for pahole's BTF converter and minor UAPI tweaks in BTF_INT_BITS()
   to shrink the mask before eventual UAPI freeze, from Martin.

2) Fix a segfault in bpftool when prog pin id has no further arguments such
   as id value or file specified, from Taeung.

3) Fix powerpc JIT handling of XADD which has jumps to exit path that would
   potentially bypass verifier expectations e.g. with subprog calls. Also add
   a test case to make sure XADD is not mangling src/dst register, from Daniel.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2018-07-20 23:57:03 -07:00
parent fcf4793e27 7c3e8b642b
commit f1d66bf9ab
6 changed files with 65 additions and 35 deletions
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29
arch/powerpc/net/bpf_jit_comp64.c
View File

@ -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 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image,
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 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image,
/* 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);
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_BCC_SHORT(COND_EQ, (ctx->idx * 4) + (7*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;
/*

2
include/uapi/linux/btf.h
View File

@ -76,7 +76,7 @@ struct btf_type {
*/
#define BTF_INT_ENCODING(VAL) (((VAL) & 0x0f000000) >> 24)
#define BTF_INT_OFFSET(VAL) (((VAL & 0x00ff0000)) >> 16)
#define BTF_INT_BITS(VAL) ((VAL) & 0x0000ffff)
#define BTF_INT_BITS(VAL) ((VAL) & 0x000000ff)
/* Attributes stored in the BTF_INT_ENCODING */
#define BTF_INT_SIGNED (1 << 0)

16
kernel/bpf/btf.c
View File

@ -450,7 +450,7 @@ static const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id)
*/
static bool btf_type_int_is_regular(const struct btf_type *t)
{
u16 nr_bits, nr_bytes;
u8 nr_bits, nr_bytes;
u32 int_data;
int_data = btf_type_int(t);
@ -993,12 +993,16 @@ static void btf_int_bits_seq_show(const struct btf *btf,
{
u16 left_shift_bits, right_shift_bits;
u32 int_data = btf_type_int(t);
u16 nr_bits = BTF_INT_BITS(int_data);
u16 total_bits_offset;
u16 nr_copy_bytes;
u16 nr_copy_bits;
u8 nr_bits = BTF_INT_BITS(int_data);
u8 total_bits_offset;
u8 nr_copy_bytes;
u8 nr_copy_bits;
u64 print_num;
/*
* bits_offset is at most 7.
* BTF_INT_OFFSET() cannot exceed 64 bits.
*/
total_bits_offset = bits_offset + BTF_INT_OFFSET(int_data);
data += BITS_ROUNDDOWN_BYTES(total_bits_offset);
bits_offset = BITS_PER_BYTE_MASKED(total_bits_offset);
@ -1028,7 +1032,7 @@ static void btf_int_seq_show(const struct btf *btf, const struct btf_type *t,
u32 int_data = btf_type_int(t);
u8 encoding = BTF_INT_ENCODING(int_data);
bool sign = encoding & BTF_INT_SIGNED;
u32 nr_bits = BTF_INT_BITS(int_data);
u8 nr_bits = BTF_INT_BITS(int_data);
if (bits_offset || BTF_INT_OFFSET(int_data) ||
BITS_PER_BYTE_MASKED(nr_bits)) {

11
tools/bpf/bpftool/common.c
View File

@ -217,6 +217,14 @@ int do_pin_any(int argc, char **argv, int (*get_fd_by_id)(__u32))
int err;
int fd;
if (argc < 3) {
p_err("too few arguments, id ID and FILE path is required");
return -1;
} else if (argc > 3) {
p_err("too many arguments");
return -1;
}
if (!is_prefix(*argv, "id")) {
p_err("expected 'id' got %s", *argv);
return -1;
@ -230,9 +238,6 @@ int do_pin_any(int argc, char **argv, int (*get_fd_by_id)(__u32))
}
NEXT_ARG();
if (argc != 1)
usage();
fd = get_fd_by_id(id);
if (fd < 0) {
p_err("can't get prog by id (%u): %s", id, strerror(errno));

2
tools/testing/selftests/bpf/Makefile
View File

@ -105,7 +105,7 @@ $(OUTPUT)/test_xdp_noinline.o: CLANG_FLAGS += -fno-inline
BTF_LLC_PROBE := $(shell $(LLC) -march=bpf -mattr=help 2>&1 | grep dwarfris)
BTF_PAHOLE_PROBE := $(shell $(BTF_PAHOLE) --help 2>&1 | grep BTF)
BTF_OBJCOPY_PROBE := $(shell $(LLVM_OBJCOPY) --version 2>&1 | grep LLVM)
BTF_OBJCOPY_PROBE := $(shell $(LLVM_OBJCOPY) --help 2>&1 | grep -i 'usage.*llvm')
ifneq ($(BTF_LLC_PROBE),)
ifneq ($(BTF_PAHOLE_PROBE),)

40
tools/testing/selftests/bpf/test_verifier.c
View File

@ -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 = {