linux/tools/lib, branch v5.9

libbpf: Fix XDP program load regression for old kernels

2020-09-24T17:33:02Z

Fix regression in libbpf, introduced by XDP link change, which causes XDP programs to fail to be loaded into kernel due to specified BPF_XDP expected_attach_type. While kernel doesn't enforce expected_attach_type for BPF_PROG_TYPE_XDP, some old kernels already support XDP program, but they don't yet recognize expected_attach_type field in bpf_attr, so setting it to non-zero value causes program load to fail. Luckily, libbpf already has a mechanism to deal with such cases, so just make expected_attach_type optional for XDP programs. Fixes: dc8698cac7aa ("libbpf: Add support for BPF XDP link") Reported-by: Nikita Shirokov Reported-by: Udip Pant Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200924171705.3803628-1-andriin@fb.com

libbpf: Fix native endian assumption when parsing BTF

2020-09-21T19:50:49Z

Code in btf__parse_raw() fails to detect raw BTF of non-native endianness and assumes it must be ELF data, which then fails to parse as ELF and yields a misleading error message: root:/# bpftool btf dump file /sys/kernel/btf/vmlinux libbpf: failed to get EHDR from /sys/kernel/btf/vmlinux For example, this could occur after cross-compiling a BTF-enabled kernel for a target with non-native endianness, which is currently unsupported. Check for correct endianness and emit a clearer error message: root:/# bpftool btf dump file /sys/kernel/btf/vmlinux libbpf: non-native BTF endianness is not supported Fixes: 94a1fedd63ed ("libbpf: Add btf__parse_raw() and generic btf__parse() APIs") Signed-off-by: Tony Ambardar Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/90f81508ecc57bc0da318e0fe0f45cfe49b17ea7.1600417359.git.Tony.Ambardar@gmail.com

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

2020-09-16T02:26:21Z

Alexei Starovoitov says: ==================== pull-request: bpf 2020-09-15 The following pull-request contains BPF updates for your *net* tree. We've added 12 non-merge commits during the last 19 day(s) which contain a total of 10 files changed, 47 insertions(+), 38 deletions(-). The main changes are: 1) docs/bpf fixes, from Andrii. 2) ld_abs fix, from Daniel. 3) socket casting helpers fix, from Martin. 4) hash iterator fixes, from Yonghong. ==================== Signed-off-by: David S. Miller

tools/libbpf: Avoid counting local symbols in ABI check

2020-09-08T22:41:31Z

Encountered the following failure building libbpf from kernel 5.8.5 sources with GCC 8.4.0 and binutils 2.34: (long paths shortened) Warning: Num of global symbols in sharedobjs/libbpf-in.o (234) does NOT match with num of versioned symbols in libbpf.so (236). Please make sure all LIBBPF_API symbols are versioned in libbpf.map. --- libbpf_global_syms.tmp 2020-09-02 07:30:58.920084380 +0000 +++ libbpf_versioned_syms.tmp 2020-09-02 07:30:58.924084388 +0000 @@ -1,3 +1,5 @@ +_fini +_init bpf_btf_get_fd_by_id bpf_btf_get_next_id bpf_create_map make[4]: *** [Makefile:210: check_abi] Error 1 Investigation shows _fini and _init are actually local symbols counted amongst global ones: $ readelf --dyn-syms --wide libbpf.so|head -10 Symbol table '.dynsym' contains 343 entries: Num: Value Size Type Bind Vis Ndx Name 0: 00000000 0 NOTYPE LOCAL DEFAULT UND 1: 00004098 0 SECTION LOCAL DEFAULT 11 2: 00004098 8 FUNC LOCAL DEFAULT 11 _init@@LIBBPF_0.0.1 3: 00023040 8 FUNC LOCAL DEFAULT 14 _fini@@LIBBPF_0.0.1 4: 00000000 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.0.4 5: 00000000 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.0.1 6: 0000ffa4 8 FUNC GLOBAL DEFAULT 12 bpf_object__find_map_by_offset@@LIBBPF_0.0.1 A previous commit filtered global symbols in sharedobjs/libbpf-in.o. Do the same with the libbpf.so DSO for consistent comparison. Fixes: 306b267cb3c4 ("libbpf: Verify versioned symbols") Signed-off-by: Tony Ambardar Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200905214831.1565465-1-Tony.Ambardar@gmail.com

libtraceevent: Fix build warning on 32-bit arches

2020-09-03T18:45:15Z

Fixed a compilation warning for casting to pointer from integer of different size on 32-bit platforms. Reported-by: Arnaldo Carvalho de Melo Signed-off-by: Tzvetomir Stoyanov (VMware) Cc: Steven Rostedt (VMware) Cc: linux-trace-devel@vger.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

libbpf: Remove arch-specific include path in Makefile

2020-09-03T13:45:00Z

Ubuntu mainline builds for ppc64le are failing with the below error (*): CALL /home/kernel/COD/linux/scripts/atomic/check-atomics.sh DESCEND bpf/resolve_btfids Auto-detecting system features: ... libelf: [ [32mon[m ] ... zlib: [ [32mon[m ] ... bpf: [ [31mOFF[m ] BPF API too old make[6]: *** [Makefile:295: bpfdep] Error 1 make[5]: *** [Makefile:54: /home/kernel/COD/linux/debian/build/build-generic/tools/bpf/resolve_btfids//libbpf.a] Error 2 make[4]: *** [Makefile:71: bpf/resolve_btfids] Error 2 make[3]: *** [/home/kernel/COD/linux/Makefile:1890: tools/bpf/resolve_btfids] Error 2 make[2]: *** [/home/kernel/COD/linux/Makefile:335: __build_one_by_one] Error 2 make[2]: Leaving directory '/home/kernel/COD/linux/debian/build/build-generic' make[1]: *** [Makefile:185: __sub-make] Error 2 make[1]: Leaving directory '/home/kernel/COD/linux' resolve_btfids needs to be build as a host binary and it needs libbpf. However, libbpf Makefile hardcodes an include path utilizing $(ARCH). This results in mixing of cross-architecture headers resulting in a build failure. The specific header include path doesn't seem necessary for a libbpf build. Hence, remove the same. (*) https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.9-rc3/ppc64el/log Reported-by: Vaidyanathan Srinivasan Signed-off-by: Naveen N. Rao Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200902084246.1513055-1-naveen.n.rao@linux.vnet.ibm.com

libbpf: Fix build failure from uninitialized variable warning

2020-08-31T14:56:51Z

While compiling libbpf, some GCC versions (at least 8.4.0) have difficulty determining control flow and a emit warning for potentially uninitialized usage of 'map', which results in a build error if using "-Werror": In file included from libbpf.c:56: libbpf.c: In function '__bpf_object__open': libbpf_internal.h:59:2: warning: 'map' may be used uninitialized in this function [-Wmaybe-uninitialized] libbpf_print(level, "libbpf: " fmt, ##__VA_ARGS__); \ ^~~~~~~~~~~~ libbpf.c:5032:18: note: 'map' was declared here struct bpf_map *map, *targ_map; ^~~ The warning/error is false based on code inspection, so silence it with a NULL initialization. Fixes: 646f02ffdd49 ("libbpf: Add BTF-defined map-in-map support") Reference: 063e68813391 ("libbpf: Fix false uninitialized variable warning") Signed-off-by: Tony Ambardar Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20200831000304.1696435-1-Tony.Ambardar@gmail.com

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

2020-08-21T19:54:50Z

Alexei Starovoitov says: ==================== pull-request: bpf 2020-08-21 The following pull-request contains BPF updates for your *net* tree. We've added 11 non-merge commits during the last 5 day(s) which contain a total of 12 files changed, 78 insertions(+), 24 deletions(-). The main changes are: 1) three fixes in BPF task iterator logic, from Yonghong. 2) fix for compressed dwarf sections in vmlinux, from Jiri. 3) fix xdp attach regression, from Andrii. ==================== Signed-off-by: David S. Miller

libbpf: Fix map index used in error message

2020-08-20T14:21:27Z

The error message emitted by bpf_object__init_user_btf_maps() was using the wrong section ID. Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Daniel Borkmann Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20200819110534.9058-1-toke@redhat.com

libbpf: Fix build on ppc64le architecture

2020-08-18T17:02:52Z

On ppc64le we get the following warning: In file included from btf_dump.c:16:0: btf_dump.c: In function ‘btf_dump_emit_struct_def’: ../include/linux/kernel.h:20:17: error: comparison of distinct pointer types lacks a cast [-Werror] (void) (&_max1 == &_max2); \ ^ btf_dump.c:882:11: note: in expansion of macro ‘max’ m_sz = max(0LL, btf__resolve_size(d->btf, m->type)); ^~~ Fix by explicitly casting to __s64, which is a return type from btf__resolve_size(). Fixes: 702eddc77a90 ("libbpf: Handle GCC built-in types for Arm NEON") Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200818164456.1181661-1-andriin@fb.com