| Message ID | 1583825550-18606-1-git-send-email-komachi.yoshiki@gmail.com |
|---|---|
| Headers | show |
| Series | Fix BTF verification of enum members with a selftest | expand |
On Tue, Mar 10, 2020 at 12:32 AM Yoshiki Komachi <komachi.yoshiki@gmail.com> wrote: > > btf_enum_check_member() checked if the size of "enum" as a struct > member exceeded struct_size or not. Then, the function compared it > with the size of "int". Although the size of "enum" is 4-byte by > default (i.e., equivalent to "int"), the packing feature enables > us to reduce it, as illustrated by the following example: > > struct A { > char m; > enum { E0, E1 } __attribute__((packed)) n; > }; > > With such a setup above, the bpf loader gave an error attempting > to load it: > > ------------------------------------------------------------------ > ... > > [3] ENUM (anon) size=1 vlen=2 > E0 val=0 > E1 val=1 > [4] STRUCT A size=2 vlen=2 > m type_id=2 bits_offset=0 > n type_id=3 bits_offset=8 > > [4] STRUCT A size=2 vlen=2 > n type_id=3 bits_offset=8 Member exceeds struct_size > > libbpf: Error loading .BTF into kernel: -22. > > ------------------------------------------------------------------ > > The related issue was previously fixed by the commit 9eea98497951 ("bpf: > fix BTF verification of enums"). On the other hand, this series fixes > this issue as well, and adds a selftest program for it. > > Changes in v2: > - change an example in commit message based on Andrii's review > - add a selftest program for packed "enum" type members in struct/union > > Yoshiki Komachi (2): > bpf/btf: Fix BTF verification of enum members in struct/union > selftests/bpf: Add test for the packed enum member in struct/union > > kernel/bpf/btf.c | 2 +- > tools/testing/selftests/bpf/test_btf.c | 42 ++++++++++++++++++++++++++++++++++ > 2 files changed, 43 insertions(+), 1 deletion(-) > > -- > 1.8.3.1 > You should have updated patch prefix for patch #1 and #2 to [PATCH v2 bpf] as well, please do it next time, For the series: Acked-by: Andrii Nakryiko <andriin@fb.com>
On Tue, Mar 10, 2020 at 04:32:28PM +0900, Yoshiki Komachi wrote: > btf_enum_check_member() checked if the size of "enum" as a struct > member exceeded struct_size or not. Then, the function compared it > with the size of "int". Although the size of "enum" is 4-byte by > default (i.e., equivalent to "int"), the packing feature enables > us to reduce it, as illustrated by the following example: > > struct A { > char m; > enum { E0, E1 } __attribute__((packed)) n; > }; > > With such a setup above, the bpf loader gave an error attempting > to load it: > > ------------------------------------------------------------------ > ... > > [3] ENUM (anon) size=1 vlen=2 > E0 val=0 > E1 val=1 > [4] STRUCT A size=2 vlen=2 > m type_id=2 bits_offset=0 > n type_id=3 bits_offset=8 > > [4] STRUCT A size=2 vlen=2 > n type_id=3 bits_offset=8 Member exceeds struct_size > > libbpf: Error loading .BTF into kernel: -22. > > ------------------------------------------------------------------ > > The related issue was previously fixed by the commit 9eea98497951 ("bpf: > fix BTF verification of enums"). On the other hand, this series fixes > this issue as well, and adds a selftest program for it. > > Changes in v2: > - change an example in commit message based on Andrii's review > - add a selftest program for packed "enum" type members in struct/union Acked-by: Martin KaFai Lau <kafai@fb.com>
On Tue, Mar 10, 2020 at 9:46 AM Martin KaFai Lau <kafai@fb.com> wrote: > > On Tue, Mar 10, 2020 at 04:32:28PM +0900, Yoshiki Komachi wrote: > > btf_enum_check_member() checked if the size of "enum" as a struct > > member exceeded struct_size or not. Then, the function compared it > > with the size of "int". Although the size of "enum" is 4-byte by > > default (i.e., equivalent to "int"), the packing feature enables > > us to reduce it, as illustrated by the following example: > > > > struct A { > > char m; > > enum { E0, E1 } __attribute__((packed)) n; > > }; > > > > With such a setup above, the bpf loader gave an error attempting > > to load it: > > > > ------------------------------------------------------------------ > > ... > > > > [3] ENUM (anon) size=1 vlen=2 > > E0 val=0 > > E1 val=1 > > [4] STRUCT A size=2 vlen=2 > > m type_id=2 bits_offset=0 > > n type_id=3 bits_offset=8 > > > > [4] STRUCT A size=2 vlen=2 > > n type_id=3 bits_offset=8 Member exceeds struct_size > > > > libbpf: Error loading .BTF into kernel: -22. > > > > ------------------------------------------------------------------ > > > > The related issue was previously fixed by the commit 9eea98497951 ("bpf: > > fix BTF verification of enums"). On the other hand, this series fixes > > this issue as well, and adds a selftest program for it. > > > > Changes in v2: > > - change an example in commit message based on Andrii's review > > - add a selftest program for packed "enum" type members in struct/union > Acked-by: Martin KaFai Lau <kafai@fb.com> Applied to bpf tree. Thanks
btf_enum_check_member() checked if the size of "enum" as a struct member exceeded struct_size or not. Then, the function compared it with the size of "int". Although the size of "enum" is 4-byte by default (i.e., equivalent to "int"), the packing feature enables us to reduce it, as illustrated by the following example: struct A { char m; enum { E0, E1 } __attribute__((packed)) n; }; With such a setup above, the bpf loader gave an error attempting to load it: ------------------------------------------------------------------ ... [3] ENUM (anon) size=1 vlen=2 E0 val=0 E1 val=1 [4] STRUCT A size=2 vlen=2 m type_id=2 bits_offset=0 n type_id=3 bits_offset=8 [4] STRUCT A size=2 vlen=2 n type_id=3 bits_offset=8 Member exceeds struct_size libbpf: Error loading .BTF into kernel: -22. ------------------------------------------------------------------ The related issue was previously fixed by the commit 9eea98497951 ("bpf: fix BTF verification of enums"). On the other hand, this series fixes this issue as well, and adds a selftest program for it. Changes in v2: - change an example in commit message based on Andrii's review - add a selftest program for packed "enum" type members in struct/union Yoshiki Komachi (2): bpf/btf: Fix BTF verification of enum members in struct/union selftests/bpf: Add test for the packed enum member in struct/union kernel/bpf/btf.c | 2 +- tools/testing/selftests/bpf/test_btf.c | 42 ++++++++++++++++++++++++++++++++++ 2 files changed, 43 insertions(+), 1 deletion(-)