linux.git/tools/lib, branch v5.17.6

perf tools: Fix segfault accessing sample_id xyarray

2022-04-27T12:40:53+00:00

commit a668cc07f990d2ed19424d5c1a529521a9d1cee1 upstream.

perf_evsel::sample_id is an xyarray which can cause a segfault when
accessed beyond its size. e.g.

  # perf record -e intel_pt// -C 1 sleep 1
  Segmentation fault (core dumped)
  #

That is happening because a dummy event is opened to capture text poke
events accross all CPUs, however the mmap logic is allocating according
to the number of user_requested_cpus.

In general, perf sometimes uses the evsel cpus to open events, and
sometimes the evlist user_requested_cpus. However, it is not necessary
to determine which case is which because the opened event file
descriptors are also in an xyarray, the size of whch can be used
to correctly allocate the size of the sample_id xyarray, because there
is one ID per file descriptor.

Note, in the affected code path, perf_evsel fd array is subsequently
used to get the file descriptor for the mmap, so it makes sense for the
xyarrays to be the same size there.

Fixes: d1a177595b3a824c ("libperf: Adopt perf_evlist__mmap()/munmap() from tools/perf")
Fixes: 246eba8e9041c477 ("perf tools: Add support for PERF_RECORD_TEXT_POKE")
Signed-off-by: Adrian Hunter 
Acked-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Jiri Olsa 
Cc: stable@vger.kernel.org # 5.5+
Link: https://lore.kernel.org/r/20220413114232.26914-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

libbpf: Fix accessing the first syscall argument on s390

2022-04-13T17:27:14+00:00

[ Upstream commit 1f22a6f9f9a0f50218a11a0554709fd34a821fa3 ]

On s390, the first syscall argument should be accessed via orig_gpr2
(see arch/s390/include/asm/syscall.h). Currently gpr[2] is used
instead, leading to bpf_syscall_macro test failure.

orig_gpr2 cannot be added to user_pt_regs, since its layout is a part
of the ABI. Therefore provide access to it only through
PT_REGS_PARM1_CORE_SYSCALL() by using a struct pt_regs flavor.

Reported-by: Andrii Nakryiko 
Signed-off-by: Ilya Leoshkevich 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20220209021745.2215452-11-iii@linux.ibm.com
Signed-off-by: Sasha Levin

libbpf: Fix accessing the first syscall argument on arm64

2022-04-13T17:27:14+00:00

[ Upstream commit fbca4a2f649730b67488a8b36140ce4d2cf13c63 ]

On arm64, the first syscall argument should be accessed via orig_x0
(see arch/arm64/include/asm/syscall.h). Currently regs[0] is used
instead, leading to bpf_syscall_macro test failure.

orig_x0 cannot be added to struct user_pt_regs, since its layout is a
part of the ABI. Therefore provide access to it only through
PT_REGS_PARM1_CORE_SYSCALL() by using a struct pt_regs flavor.

Reported-by: Heiko Carstens 
Signed-off-by: Ilya Leoshkevich 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20220209021745.2215452-10-iii@linux.ibm.com
Signed-off-by: Sasha Levin

libbpf: Fix accessing syscall arguments on powerpc

2022-04-13T17:27:13+00:00

[ Upstream commit f07f1503469b11b739892d50c836992ffbe026ee ]

powerpc does not select ARCH_HAS_SYSCALL_WRAPPER, so its syscall
handlers take "unpacked" syscall arguments. Indicate this to libbpf
using PT_REGS_SYSCALL_REGS macro.

Reported-by: Heiko Carstens 
Signed-off-by: Ilya Leoshkevich 
Signed-off-by: Andrii Nakryiko 
Tested-by: Naveen N. Rao 
Link: https://lore.kernel.org/bpf/20220209021745.2215452-5-iii@linux.ibm.com
Signed-off-by: Sasha Levin

libbpf: Fix build issue with llvm-readelf

2022-04-13T17:27:12+00:00

[ Upstream commit 0908a66ad1124c1634c33847ac662106f7f2c198 ]

There are cases where clang compiler is packaged in a way
readelf is a symbolic link to llvm-readelf. In such cases,
llvm-readelf will be used instead of default binutils readelf,
and the following error will appear during libbpf build:

#  Warning: Num of global symbols in
#   /home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/libbpf-in.o (367)
#   does NOT match with num of versioned symbols in
#   /home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/libbpf.so libbpf.map (383).
#   Please make sure all LIBBPF_API symbols are versioned in libbpf.map.
#  --- /home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/libbpf_global_syms.tmp ...
#  +++ /home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/libbpf_versioned_syms.tmp ...
#  @@ -324,6 +324,22 @@
#   btf__str_by_offset
#   btf__type_by_id
#   btf__type_cnt
#  +LIBBPF_0.0.1
#  +LIBBPF_0.0.2
#  +LIBBPF_0.0.3
#  +LIBBPF_0.0.4
#  +LIBBPF_0.0.5
#  +LIBBPF_0.0.6
#  +LIBBPF_0.0.7
#  +LIBBPF_0.0.8
#  +LIBBPF_0.0.9
#  +LIBBPF_0.1.0
#  +LIBBPF_0.2.0
#  +LIBBPF_0.3.0
#  +LIBBPF_0.4.0
#  +LIBBPF_0.5.0
#  +LIBBPF_0.6.0
#  +LIBBPF_0.7.0
#   libbpf_attach_type_by_name
#   libbpf_find_kernel_btf
#   libbpf_find_vmlinux_btf_id
#  make[2]: *** [Makefile:184: check_abi] Error 1
#  make[1]: *** [Makefile:140: all] Error 2

The above failure is due to different printouts for some ABS
versioned symbols. For example, with the same libbpf.so,
  $ /bin/readelf --dyn-syms --wide tools/lib/bpf/libbpf.so | grep "LIBBPF" | grep ABS
     134: 0000000000000000     0 OBJECT  GLOBAL DEFAULT  ABS LIBBPF_0.5.0
     202: 0000000000000000     0 OBJECT  GLOBAL DEFAULT  ABS LIBBPF_0.6.0
     ...
  $ /opt/llvm/bin/readelf --dyn-syms --wide tools/lib/bpf/libbpf.so | grep "LIBBPF" | grep ABS
     134: 0000000000000000     0 OBJECT  GLOBAL DEFAULT   ABS LIBBPF_0.5.0@@LIBBPF_0.5.0
     202: 0000000000000000     0 OBJECT  GLOBAL DEFAULT   ABS LIBBPF_0.6.0@@LIBBPF_0.6.0
     ...
The binutils readelf doesn't print out the symbol LIBBPF_* version and llvm-readelf does.
Such a difference caused libbpf build failure with llvm-readelf.

The proposed fix filters out all ABS symbols as they are not part of the comparison.
This works for both binutils readelf and llvm-readelf.

Reported-by: Delyan Kratunov 
Signed-off-by: Yonghong Song 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20220204214355.502108-1-yhs@fb.com
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

libbpf: Define BTF_KIND_* constants in btf.h to avoid compilation errors

2022-04-08T11:59:00+00:00

commit eaa266d83a3730a15de2ceebcc89e8f6290e8cf6 upstream.

The btf.h header included with libbpf contains inline helper functions to
check for various BTF kinds. These helpers directly reference the
BTF_KIND_* constants defined in the kernel header, and because the header
file is included in user applications, this happens in the user application
compile units.

This presents a problem if a user application is compiled on a system with
older kernel headers because the constants are not available. To avoid
this, add #defines of the constants directly in btf.h before using them.

Since the kernel header moved to an enum for BTF_KIND_*, the #defines can
shadow the enum values without any errors, so we only need #ifndef guards
for the constants that predates the conversion to enum. We group these so
there's only one guard for groups of values that were added together.

  [0] Closes: https://github.com/libbpf/libbpf/issues/436

Fixes: 223f903e9c83 ("bpf: Rename BTF_KIND_TAG to BTF_KIND_DECL_TAG")
Fixes: 5b84bd10363e ("libbpf: Add support for BTF_KIND_TAG")
Signed-off-by: Toke Høiland-Jørgensen 
Signed-off-by: Andrii Nakryiko 
Acked-by: Arnaldo Carvalho de Melo 
Link: https://lore.kernel.org/bpf/20220118141327.34231-1-toke@redhat.com
Signed-off-by: Greg Kroah-Hartman

libperf tests: Fix typo in perf_evlist__open() failure error messages

2022-04-08T11:58:33+00:00

[ Upstream commit c2eeac985657f61543e6c5a333b94f3bd18e6b9d ]

This patch corrects typos in error messages. I should be "evlist", not
"evsel" as the function that fails is perf_evlist__open().

Fixes: 3ce311afb5583cf3 ("libperf: Move to tools/lib/perf")
Fixes: a7f3713f6bf207e6 ("libperf tests: Add test_stat_multiplexing test")
Signed-off-by: Shunsuke Nakamura 
Cc: Alexander Shishkin 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lore.kernel.org/lkml/20220325043829.224045-2-nakamura.shun@fujitsu.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

libbpf: Unmap rings when umem deleted

2022-04-08T11:58:16+00:00

[ Upstream commit 9c6e6a80ee741adf6cb3cfd8eef7d1554f91fceb ]

xsk_umem__create() does mmap for fill/comp rings, but xsk_umem__delete()
doesn't do the unmap. This works fine for regular cases, because
xsk_socket__delete() does unmap for the rings. But for the case that
xsk_socket__create_shared() fails, umem rings are not unmapped.

fill_save/comp_save are checked to determine if rings have already be
unmapped by xsk. If fill_save and comp_save are NULL, it means that the
rings have already been used by xsk. Then they are supposed to be
unmapped by xsk_socket__delete(). Otherwise, xsk_umem__delete() does the
unmap.

Fixes: 2f6324a3937f ("libbpf: Support shared umems between queues and devices")
Signed-off-by: Cheng Li 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20220301132623.GA19995@vscode.7~
Signed-off-by: Sasha Levin

libbpf: Skip forward declaration when counting duplicated type names

2022-04-08T11:58:14+00:00

[ Upstream commit 4226961b0019b2e1612029e8950a9e911affc995 ]

Currently if a declaration appears in the BTF before the definition, the
definition is dumped as a conflicting name, e.g.:

    $ bpftool btf dump file vmlinux format raw | grep "'unix_sock'"
    [81287] FWD 'unix_sock' fwd_kind=struct
    [89336] STRUCT 'unix_sock' size=1024 vlen=14

    $ bpftool btf dump file vmlinux format c | grep "struct unix_sock"
    struct unix_sock;
    struct unix_sock___2 {	<--- conflict, the "___2" is unexpected
		    struct unix_sock___2 *unix_sk;

This causes a compilation error if the dump output is used as a header file.

Fix it by skipping declaration when counting duplicated type names.

Fixes: 351131b51c7a ("libbpf: add btf_dump API for BTF-to-C conversion")
Signed-off-by: Xu Kuohai 
Signed-off-by: Daniel Borkmann 
Acked-by: Song Liu 
Link: https://lore.kernel.org/bpf/20220301053250.1464204-2-xukuohai@huawei.com
Signed-off-by: Sasha Levin

libbpf: Fix BPF_MAP_TYPE_PERF_EVENT_ARRAY auto-pinning

2022-04-08T11:58:13+00:00

[ Upstream commit a4fbfdd7a160eccaafc093eb5b34f838b1ca0bf0 ]

When a BPF map of type BPF_MAP_TYPE_PERF_EVENT_ARRAY doesn't have the
max_entries parameter set, the map will be created with max_entries set
to the number of available CPUs. When we try to reuse such a pinned map,
map_is_reuse_compat will return false, as max_entries in the map
definition differs from max_entries of the existing map, causing the
following error:

  libbpf: couldn't reuse pinned map at '/sys/fs/bpf/m_logging': parameter mismatch

Fix this by overwriting max_entries in the map definition. For this to
work, we need to do this in bpf_object__create_maps, before calling
bpf_object__reuse_map.

Fixes: 57a00f41644f ("libbpf: Add auto-pinning of maps when loading BPF objects")
Signed-off-by: Stijn Tintel 
Signed-off-by: Daniel Borkmann 
Acked-by: Song Liu 
Link: https://lore.kernel.org/bpf/20220225152355.315204-1-stijn@linux-ipv6.be
Signed-off-by: Sasha Levin