From 17e3ac812541f73224299d8958ddb420c2d5bbd8 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Thu, 10 Jan 2019 11:14:00 -0800 Subject: [PATCH 1/3] bpf: fix bpffs bitfield pretty print Commit 9d5f9f701b18 ("bpf: btf: fix struct/union/fwd types with kind_flag") introduced kind_flag and used bitfield_size in the btf_member to directly pretty print member values. The commit contained a bug where the incorrect parameters could be passed to function btf_bitfield_seq_show(). The bits_offset parameter in the function expects a value less than 8. Instead, the member offset in the structure is passed. The below is btf_bitfield_seq_show() func signature: void btf_bitfield_seq_show(void *data, u8 bits_offset, u8 nr_bits, struct seq_file *m) both bits_offset and nr_bits are u8 type. If the bitfield member offset is greater than 256, incorrect value will be printed. This patch fixed the issue by calculating correct proper data offset and bits_offset similar to non kind_flag case. Fixes: 9d5f9f701b18 ("bpf: btf: fix struct/union/fwd types with kind_flag") Acked-by: Martin KaFai Lau Signed-off-by: Yonghong Song Signed-off-by: Daniel Borkmann --- kernel/bpf/btf.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 715f9fcf4712..a2f53642592b 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -1219,8 +1219,6 @@ static void btf_bitfield_seq_show(void *data, u8 bits_offset, u8 nr_copy_bits; u64 print_num; - data += BITS_ROUNDDOWN_BYTES(bits_offset); - bits_offset = BITS_PER_BYTE_MASKED(bits_offset); nr_copy_bits = nr_bits + bits_offset; nr_copy_bytes = BITS_ROUNDUP_BYTES(nr_copy_bits); @@ -1255,7 +1253,9 @@ static void btf_int_bits_seq_show(const struct btf *btf, * BTF_INT_OFFSET() cannot exceed 64 bits. */ total_bits_offset = bits_offset + BTF_INT_OFFSET(int_data); - btf_bitfield_seq_show(data, total_bits_offset, nr_bits, m); + data += BITS_ROUNDDOWN_BYTES(total_bits_offset); + bits_offset = BITS_PER_BYTE_MASKED(total_bits_offset); + btf_bitfield_seq_show(data, bits_offset, nr_bits, m); } static void btf_int_seq_show(const struct btf *btf, const struct btf_type *t, @@ -2001,12 +2001,12 @@ static void btf_struct_seq_show(const struct btf *btf, const struct btf_type *t, member_offset = btf_member_bit_offset(t, member); bitfield_size = btf_member_bitfield_size(t, member); + bytes_offset = BITS_ROUNDDOWN_BYTES(member_offset); + bits8_offset = BITS_PER_BYTE_MASKED(member_offset); if (bitfield_size) { - btf_bitfield_seq_show(data, member_offset, + btf_bitfield_seq_show(data + bytes_offset, bits8_offset, bitfield_size, m); } else { - bytes_offset = BITS_ROUNDDOWN_BYTES(member_offset); - bits8_offset = BITS_PER_BYTE_MASKED(member_offset); ops = btf_type_ops(member_type); ops->seq_show(btf, member_type, member->type, data + bytes_offset, bits8_offset, m); From e43207fa2e6130e39e3aca4c55e2ee21cfb46828 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Thu, 10 Jan 2019 11:14:01 -0800 Subject: [PATCH 2/3] tools/bpf: test btf bitfield with >=256 struct member offset This patch modified test_btf pretty print test to cover the bitfield with struct member equal to or greater 256. Without the previous kernel patch fix, the modified test will fail: $ test_btf -p ...... BTF pretty print array(#1)......unexpected pprint output expected: 0: {0,0,0,0x3,0x0,0x3,{0|[0,0,0,0,0,0,0,0]},ENUM_ZERO,4,0x1} read: 0: {0,0,0,0x3,0x0,0x3,{0|[0,0,0,0,0,0,0,0]},ENUM_ZERO,4,0x0} BTF pretty print array(#2)......unexpected pprint output expected: 0: {0,0,0,0x3,0x0,0x3,{0|[0,0,0,0,0,0,0,0]},ENUM_ZERO,4,0x1} read: 0: {0,0,0,0x3,0x0,0x3,{0|[0,0,0,0,0,0,0,0]},ENUM_ZERO,4,0x0} PASS:6 SKIP:0 FAIL:2 With the kernel fix, the modified test will succeed: $ test_btf -p ...... BTF pretty print array(#1)......OK BTF pretty print array(#2)......OK PASS:8 SKIP:0 FAIL:0 Fixes: 9d5f9f701b18 ("bpf: btf: fix struct/union/fwd types with kind_flag") Acked-by: Martin KaFai Lau Signed-off-by: Yonghong Song Signed-off-by: Daniel Borkmann --- tools/testing/selftests/bpf/test_btf.c | 29 +++++++++++++++++++------- 1 file changed, 21 insertions(+), 8 deletions(-) diff --git a/tools/testing/selftests/bpf/test_btf.c b/tools/testing/selftests/bpf/test_btf.c index 8bcd38010582..a0bd04befe87 100644 --- a/tools/testing/selftests/bpf/test_btf.c +++ b/tools/testing/selftests/bpf/test_btf.c @@ -3526,6 +3526,8 @@ struct pprint_mapv { ENUM_TWO, ENUM_THREE, } aenum; + uint32_t ui32b; + uint32_t bits2c:2; }; static struct btf_raw_test pprint_test_template[] = { @@ -3568,7 +3570,7 @@ static struct btf_raw_test pprint_test_template[] = { BTF_ENUM_ENC(NAME_TBD, 2), BTF_ENUM_ENC(NAME_TBD, 3), /* struct pprint_mapv */ /* [16] */ - BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 8), 32), + BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 10), 40), BTF_MEMBER_ENC(NAME_TBD, 11, 0), /* uint32_t ui32 */ BTF_MEMBER_ENC(NAME_TBD, 10, 32), /* uint16_t ui16 */ BTF_MEMBER_ENC(NAME_TBD, 12, 64), /* int32_t si32 */ @@ -3577,9 +3579,11 @@ static struct btf_raw_test pprint_test_template[] = { BTF_MEMBER_ENC(NAME_TBD, 6, 126), /* unused_bits2b */ BTF_MEMBER_ENC(0, 14, 128), /* union (anon) */ BTF_MEMBER_ENC(NAME_TBD, 15, 192), /* aenum */ + BTF_MEMBER_ENC(NAME_TBD, 11, 224), /* uint32_t ui32b */ + BTF_MEMBER_ENC(NAME_TBD, 6, 256), /* bits2c */ BTF_END_RAW, }, - BTF_STR_SEC("\0unsigned char\0unsigned short\0unsigned int\0int\0unsigned long long\0uint8_t\0uint16_t\0uint32_t\0int32_t\0uint64_t\0ui64\0ui8a\0ENUM_ZERO\0ENUM_ONE\0ENUM_TWO\0ENUM_THREE\0pprint_mapv\0ui32\0ui16\0si32\0unused_bits2a\0bits28\0unused_bits2b\0aenum"), + BTF_STR_SEC("\0unsigned char\0unsigned short\0unsigned int\0int\0unsigned long long\0uint8_t\0uint16_t\0uint32_t\0int32_t\0uint64_t\0ui64\0ui8a\0ENUM_ZERO\0ENUM_ONE\0ENUM_TWO\0ENUM_THREE\0pprint_mapv\0ui32\0ui16\0si32\0unused_bits2a\0bits28\0unused_bits2b\0aenum\0ui32b\0bits2c"), .key_size = sizeof(unsigned int), .value_size = sizeof(struct pprint_mapv), .key_type_id = 3, /* unsigned int */ @@ -3628,7 +3632,7 @@ static struct btf_raw_test pprint_test_template[] = { BTF_ENUM_ENC(NAME_TBD, 2), BTF_ENUM_ENC(NAME_TBD, 3), /* struct pprint_mapv */ /* [16] */ - BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_STRUCT, 1, 8), 32), + BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_STRUCT, 1, 10), 40), BTF_MEMBER_ENC(NAME_TBD, 11, BTF_MEMBER_OFFSET(0, 0)), /* uint32_t ui32 */ BTF_MEMBER_ENC(NAME_TBD, 10, BTF_MEMBER_OFFSET(0, 32)), /* uint16_t ui16 */ BTF_MEMBER_ENC(NAME_TBD, 12, BTF_MEMBER_OFFSET(0, 64)), /* int32_t si32 */ @@ -3637,9 +3641,11 @@ static struct btf_raw_test pprint_test_template[] = { BTF_MEMBER_ENC(NAME_TBD, 6, BTF_MEMBER_OFFSET(2, 126)), /* unused_bits2b */ BTF_MEMBER_ENC(0, 14, BTF_MEMBER_OFFSET(0, 128)), /* union (anon) */ BTF_MEMBER_ENC(NAME_TBD, 15, BTF_MEMBER_OFFSET(0, 192)), /* aenum */ + BTF_MEMBER_ENC(NAME_TBD, 11, BTF_MEMBER_OFFSET(0, 224)), /* uint32_t ui32b */ + BTF_MEMBER_ENC(NAME_TBD, 6, BTF_MEMBER_OFFSET(2, 256)), /* bits2c */ BTF_END_RAW, }, - BTF_STR_SEC("\0unsigned char\0unsigned short\0unsigned int\0int\0unsigned long long\0uint8_t\0uint16_t\0uint32_t\0int32_t\0uint64_t\0ui64\0ui8a\0ENUM_ZERO\0ENUM_ONE\0ENUM_TWO\0ENUM_THREE\0pprint_mapv\0ui32\0ui16\0si32\0unused_bits2a\0bits28\0unused_bits2b\0aenum"), + BTF_STR_SEC("\0unsigned char\0unsigned short\0unsigned int\0int\0unsigned long long\0uint8_t\0uint16_t\0uint32_t\0int32_t\0uint64_t\0ui64\0ui8a\0ENUM_ZERO\0ENUM_ONE\0ENUM_TWO\0ENUM_THREE\0pprint_mapv\0ui32\0ui16\0si32\0unused_bits2a\0bits28\0unused_bits2b\0aenum\0ui32b\0bits2c"), .key_size = sizeof(unsigned int), .value_size = sizeof(struct pprint_mapv), .key_type_id = 3, /* unsigned int */ @@ -3690,7 +3696,7 @@ static struct btf_raw_test pprint_test_template[] = { BTF_ENUM_ENC(NAME_TBD, 2), BTF_ENUM_ENC(NAME_TBD, 3), /* struct pprint_mapv */ /* [16] */ - BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_STRUCT, 1, 8), 32), + BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_STRUCT, 1, 10), 40), BTF_MEMBER_ENC(NAME_TBD, 11, BTF_MEMBER_OFFSET(0, 0)), /* uint32_t ui32 */ BTF_MEMBER_ENC(NAME_TBD, 10, BTF_MEMBER_OFFSET(0, 32)), /* uint16_t ui16 */ BTF_MEMBER_ENC(NAME_TBD, 12, BTF_MEMBER_OFFSET(0, 64)), /* int32_t si32 */ @@ -3699,13 +3705,15 @@ static struct btf_raw_test pprint_test_template[] = { BTF_MEMBER_ENC(NAME_TBD, 19, BTF_MEMBER_OFFSET(2, 126)),/* unused_bits2b */ BTF_MEMBER_ENC(0, 14, BTF_MEMBER_OFFSET(0, 128)), /* union (anon) */ BTF_MEMBER_ENC(NAME_TBD, 15, BTF_MEMBER_OFFSET(0, 192)), /* aenum */ + BTF_MEMBER_ENC(NAME_TBD, 11, BTF_MEMBER_OFFSET(0, 224)), /* uint32_t ui32b */ + BTF_MEMBER_ENC(NAME_TBD, 17, BTF_MEMBER_OFFSET(2, 256)), /* bits2c */ /* typedef unsigned int ___int */ /* [17] */ BTF_TYPEDEF_ENC(NAME_TBD, 18), BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_VOLATILE, 0, 0), 6), /* [18] */ BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_CONST, 0, 0), 15), /* [19] */ BTF_END_RAW, }, - BTF_STR_SEC("\0unsigned char\0unsigned short\0unsigned int\0int\0unsigned long long\0uint8_t\0uint16_t\0uint32_t\0int32_t\0uint64_t\0ui64\0ui8a\0ENUM_ZERO\0ENUM_ONE\0ENUM_TWO\0ENUM_THREE\0pprint_mapv\0ui32\0ui16\0si32\0unused_bits2a\0bits28\0unused_bits2b\0aenum\0___int"), + BTF_STR_SEC("\0unsigned char\0unsigned short\0unsigned int\0int\0unsigned long long\0uint8_t\0uint16_t\0uint32_t\0int32_t\0uint64_t\0ui64\0ui8a\0ENUM_ZERO\0ENUM_ONE\0ENUM_TWO\0ENUM_THREE\0pprint_mapv\0ui32\0ui16\0si32\0unused_bits2a\0bits28\0unused_bits2b\0aenum\0ui32b\0bits2c\0___int"), .key_size = sizeof(unsigned int), .value_size = sizeof(struct pprint_mapv), .key_type_id = 3, /* unsigned int */ @@ -3793,6 +3801,8 @@ static void set_pprint_mapv(struct pprint_mapv *v, uint32_t i, v->unused_bits2b = 3; v->ui64 = i; v->aenum = i & 0x03; + v->ui32b = 4; + v->bits2c = 1; v = (void *)v + rounded_value_size; } } @@ -3955,7 +3965,8 @@ static int do_test_pprint(int test_num) nexpected_line = snprintf(expected_line, sizeof(expected_line), "%s%u: {%u,0,%d,0x%x,0x%x,0x%x," - "{%lu|[%u,%u,%u,%u,%u,%u,%u,%u]},%s}\n", + "{%lu|[%u,%u,%u,%u,%u,%u,%u,%u]},%s," + "%u,0x%x}\n", percpu_map ? "\tcpu" : "", percpu_map ? cpu : next_key, cmapv->ui32, cmapv->si32, @@ -3967,7 +3978,9 @@ static int do_test_pprint(int test_num) cmapv->ui8a[2], cmapv->ui8a[3], cmapv->ui8a[4], cmapv->ui8a[5], cmapv->ui8a[6], cmapv->ui8a[7], - pprint_enum_str[cmapv->aenum]); + pprint_enum_str[cmapv->aenum], + cmapv->ui32b, + cmapv->bits2c); err = check_line(expected_line, nexpected_line, sizeof(expected_line), line); From 298e59d322954e89ed2a556c601a04a4c007d1b3 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Thu, 10 Jan 2019 11:14:02 -0800 Subject: [PATCH 3/3] tools/bpf: fix bpftool map dump with bitfields Commit 8772c8bc093b ("tools: bpftool: support pretty print with kind_flag set") added bpftool map dump with kind_flag support. When bitfield_size can be retrieved directly from btf_member, function btf_dumper_bitfield() is called to dump the bitfield. The implementation passed the wrong parameter "bit_offset" to the function. The excepted value is the bit_offset within a byte while the passed-in value is the struct member offset. This commit fixed the bug with passing correct "bit_offset" with adjusted data pointer. Fixes: 8772c8bc093b ("tools: bpftool: support pretty print with kind_flag set") Acked-by: Martin KaFai Lau Signed-off-by: Yonghong Song Signed-off-by: Daniel Borkmann --- tools/bpf/bpftool/btf_dumper.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/tools/bpf/bpftool/btf_dumper.c b/tools/bpf/bpftool/btf_dumper.c index 3f0629edbca5..6ba5f567a9d8 100644 --- a/tools/bpf/bpftool/btf_dumper.c +++ b/tools/bpf/bpftool/btf_dumper.c @@ -82,8 +82,6 @@ static void btf_dumper_bitfield(__u32 nr_bits, __u8 bit_offset, int bits_to_copy; __u64 print_num; - data += BITS_ROUNDDOWN_BYTES(bit_offset); - bit_offset = BITS_PER_BYTE_MASKED(bit_offset); bits_to_copy = bit_offset + nr_bits; bytes_to_copy = BITS_ROUNDUP_BYTES(bits_to_copy); @@ -118,7 +116,9 @@ static void btf_dumper_int_bits(__u32 int_type, __u8 bit_offset, * BTF_INT_OFFSET() cannot exceed 64 bits. */ total_bits_offset = bit_offset + BTF_INT_OFFSET(int_type); - btf_dumper_bitfield(nr_bits, total_bits_offset, data, jw, + data += BITS_ROUNDDOWN_BYTES(total_bits_offset); + bit_offset = BITS_PER_BYTE_MASKED(total_bits_offset); + btf_dumper_bitfield(nr_bits, bit_offset, data, jw, is_plain_text); } @@ -216,11 +216,12 @@ static int btf_dumper_struct(const struct btf_dumper *d, __u32 type_id, } jsonw_name(d->jw, btf__name_by_offset(d->btf, m[i].name_off)); + data_off = data + BITS_ROUNDDOWN_BYTES(bit_offset); if (bitfield_size) { - btf_dumper_bitfield(bitfield_size, bit_offset, - data, d->jw, d->is_plain_text); + btf_dumper_bitfield(bitfield_size, + BITS_PER_BYTE_MASKED(bit_offset), + data_off, d->jw, d->is_plain_text); } else { - data_off = data + BITS_ROUNDDOWN_BYTES(bit_offset); ret = btf_dumper_do_type(d, m[i].type, BITS_PER_BYTE_MASKED(bit_offset), data_off);