linux.git/tools/lib, branch v5.5.12 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git tools lib api fs: Fix gcc9 stringop-truncation compilation error 2020-02-24T07:38:23+00:00 Andrey Zhizhikin andrey.z@gmail.com 2019-12-11T08:01:09+00:00 42dbab0ca8efcc30859b2ec15b12c8bf85a00de2 [ Upstream commit 6794200fa3c9c3e6759dae099145f23e4310f4f7 ] GCC9 introduced string hardening mechanisms, which exhibits the error during fs api compilation: error: '__builtin_strncpy' specified bound 4096 equals destination size [-Werror=stringop-truncation] This comes when the length of copy passed to strncpy is is equal to destination size, which could potentially lead to buffer overflow. There is a need to mitigate this potential issue by limiting the size of destination by 1 and explicitly terminate the destination with NULL. Signed-off-by: Andrey Zhizhikin <andrey.zhizhikin@leica-geosystems.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrii Nakryiko <andriin@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Martin KaFai Lau <kafai@fb.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Song Liu <songliubraving@fb.com> Cc: Yonghong Song <yhs@fb.com> Cc: bpf@vger.kernel.org Cc: netdev@vger.kernel.org Link: http://lore.kernel.org/lkml/20191211080109.18765-1-andrey.zhizhikin@leica-geosystems.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 6794200fa3c9c3e6759dae099145f23e4310f4f7 ]

GCC9 introduced string hardening mechanisms, which exhibits the error
during fs api compilation:

error: '__builtin_strncpy' specified bound 4096 equals destination size
[-Werror=stringop-truncation]

This comes when the length of copy passed to strncpy is is equal to
destination size, which could potentially lead to buffer overflow.

There is a need to mitigate this potential issue by limiting the size of
destination by 1 and explicitly terminate the destination with NULL.

Signed-off-by: Andrey Zhizhikin <andrey.zhizhikin@leica-geosystems.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andriin@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org
Link: http://lore.kernel.org/lkml/20191211080109.18765-1-andrey.zhizhikin@leica-geosystems.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
libbpf: Extract and generalize CPU mask parsing logic 2020-02-11T12:37:22+00:00 Andrii Nakryiko andriin@fb.com 2019-12-12T01:35:48+00:00 4f76d1a3690928dcc526155144864b78bab17258 commit 6803ee25f0ead1e836808acb14396bb9a9849113 upstream. This logic is re-used for parsing a set of online CPUs. Having it as an isolated piece of code working with input string makes it conveninent to test this logic as well. While refactoring, also improve the robustness of original implementation. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191212013548.1690564-1-andriin@fb.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 6803ee25f0ead1e836808acb14396bb9a9849113 upstream.

This logic is re-used for parsing a set of online CPUs. Having it as an
isolated piece of code working with input string makes it conveninent to test
this logic as well. While refactoring, also improve the robustness of original
implementation.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191212013548.1690564-1-andriin@fb.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
libbpf: Fix realloc usage in bpf_core_find_cands 2020-02-11T12:36:59+00:00 Andrii Nakryiko andriin@fb.com 2020-01-24T20:18:46+00:00 b10e1adbc7215956eacbdc13faa2102c977b3183 commit 35b9211c0a2427e8f39e534f442f43804fc8d5ca upstream. Fix bug requesting invalid size of reallocated array when constructing CO-RE relocation candidate list. This can cause problems if there are many potential candidates and a very fine-grained memory allocator bucket sizes are used. Fixes: ddc7c3042614 ("libbpf: implement BPF CO-RE offset relocation algorithm") Reported-by: William Smith <williampsmith@fb.com> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20200124201847.212528-1-andriin@fb.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 35b9211c0a2427e8f39e534f442f43804fc8d5ca upstream.

Fix bug requesting invalid size of reallocated array when constructing CO-RE
relocation candidate list. This can cause problems if there are many potential
candidates and a very fine-grained memory allocator bucket sizes are used.

Fixes: ddc7c3042614 ("libbpf: implement BPF CO-RE offset relocation algorithm")
Reported-by: William Smith <williampsmith@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200124201847.212528-1-andriin@fb.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
libbpf: Add missing newline in opts validation macro 2020-02-11T12:36:59+00:00 Toke Høiland-Jørgensen toke@redhat.com 2019-12-19T12:07:14+00:00 035e7fc14211eccd06d5763b104237146247f909 commit 12dd14b230b3c742b80272ecb8a83cdf824625ca upstream. The error log output in the opts validation macro was missing a newline. Fixes: 2ce8450ef5a3 ("libbpf: add bpf_object__open_{file, mem} w/ extensible opts") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191219120714.928380-1-toke@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 12dd14b230b3c742b80272ecb8a83cdf824625ca upstream.

The error log output in the opts validation macro was missing a newline.

Fixes: 2ce8450ef5a3 ("libbpf: add bpf_object__open_{file, mem} w/ extensible opts")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191219120714.928380-1-toke@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
libbpf: Don't attach perf_buffer to offline/missing CPUs 2020-02-11T12:36:59+00:00 Andrii Nakryiko andriin@fb.com 2019-12-12T01:36:09+00:00 919f4ac40ad85291a10c0f17f782cf2851bc737d commit 783b8f01f5942a786998f5577bd9ff3992f22a1a upstream. It's quite common on some systems to have more CPUs enlisted as "possible", than there are (and could ever be) present/online CPUs. In such cases, perf_buffer creationg will fail due to inability to create perf event on missing CPU with error like this: libbpf: failed to open perf buffer event on cpu #16: No such device This patch fixes the logic of perf_buffer__new() to ignore CPUs that are missing or currently offline. In rare cases where user explicitly listed specific CPUs to connect to, behavior is unchanged: libbpf will try to open perf event buffer on specified CPU(s) anyways. Fixes: fb84b8224655 ("libbpf: add perf buffer API") Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191212013609.1691168-1-andriin@fb.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 783b8f01f5942a786998f5577bd9ff3992f22a1a upstream.

It's quite common on some systems to have more CPUs enlisted as "possible",
than there are (and could ever be) present/online CPUs. In such cases,
perf_buffer creationg will fail due to inability to create perf event on
missing CPU with error like this:

libbpf: failed to open perf buffer event on cpu #16: No such device

This patch fixes the logic of perf_buffer__new() to ignore CPUs that are
missing or currently offline. In rare cases where user explicitly listed
specific CPUs to connect to, behavior is unchanged: libbpf will try to open
perf event buffer on specified CPU(s) anyways.

Fixes: fb84b8224655 ("libbpf: add perf buffer API")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191212013609.1691168-1-andriin@fb.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
libbpf: Fix printf compilation warnings on ppc64le arch 2020-02-11T12:36:58+00:00 Andrii Nakryiko andriin@fb.com 2019-12-12T17:19:18+00:00 11cee08dce69360d7a233c18b867fa1dbef1d04a commit 679152d3a32e305c213f83160c328c37566ae8bc upstream. On ppc64le __u64 and __s64 are defined as long int and unsigned long int, respectively. This causes compiler to emit warning when %lld/%llu are used to printf 64-bit numbers. Fix this by casting to size_t/ssize_t with %zu and %zd format specifiers, respectively. v1->v2: - use size_t/ssize_t instead of custom typedefs (Martin). Fixes: 1f8e2bcb2cd5 ("libbpf: Refactor relocation handling") Fixes: abd29c931459 ("libbpf: allow specifying map definitions using BTF") Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20191212171918.638010-1-andriin@fb.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 679152d3a32e305c213f83160c328c37566ae8bc upstream.

On ppc64le __u64 and __s64 are defined as long int and unsigned long int,
respectively. This causes compiler to emit warning when %lld/%llu are used to
printf 64-bit numbers. Fix this by casting to size_t/ssize_t with %zu and %zd
format specifiers, respectively.

v1->v2:
- use size_t/ssize_t instead of custom typedefs (Martin).

Fixes: 1f8e2bcb2cd5 ("libbpf: Refactor relocation handling")
Fixes: abd29c931459 ("libbpf: allow specifying map definitions using BTF")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191212171918.638010-1-andriin@fb.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
libbpf: Fix readelf output parsing for Fedora 2020-02-11T12:36:58+00:00 Thadeu Lima de Souza Cascardo cascardo@canonical.com 2019-12-13T10:11:14+00:00 9a5d50b023de4a27e4184cd7a883c55d530cc11a commit aa915931ac3e53ccf371308e6750da510e3591dd upstream. Fedora binutils has been patched to show "other info" for a symbol at the end of the line. This was done in order to support unmaintained scripts that would break with the extra info. [1] [1] https://src.fedoraproject.org/rpms/binutils/c/b8265c46f7ddae23a792ee8306fbaaeacba83bf8 This in turn has been done to fix the build of ruby, because of checksec. [2] Thanks Michael Ellerman for the pointer. [2] https://bugzilla.redhat.com/show_bug.cgi?id=1479302 As libbpf Makefile is not unmaintained, we can simply deal with either output format, by just removing the "other info" field, as it always comes inside brackets. Fixes: 3464afdf11f9 (libbpf: Fix readelf output parsing on powerpc with recent binutils) Reported-by: Justin Forbes <jmforbes@linuxtx.org> Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Cc: Aurelien Jarno <aurelien@aurel32.net> Link: https://lore.kernel.org/bpf/20191213101114.GA3986@calabresa Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit aa915931ac3e53ccf371308e6750da510e3591dd upstream.

Fedora binutils has been patched to show "other info" for a symbol at the
end of the line. This was done in order to support unmaintained scripts
that would break with the extra info. [1]

[1] https://src.fedoraproject.org/rpms/binutils/c/b8265c46f7ddae23a792ee8306fbaaeacba83bf8

This in turn has been done to fix the build of ruby, because of checksec.
[2] Thanks Michael Ellerman for the pointer.

[2] https://bugzilla.redhat.com/show_bug.cgi?id=1479302

As libbpf Makefile is not unmaintained, we can simply deal with either
output format, by just removing the "other info" field, as it always comes
inside brackets.

Fixes: 3464afdf11f9 (libbpf: Fix readelf output parsing on powerpc with recent binutils)
Reported-by: Justin Forbes <jmforbes@linuxtx.org>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Link: https://lore.kernel.org/bpf/20191213101114.GA3986@calabresa
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tools lib: Fix builds when glibc contains strlcpy() 2020-02-04T18:18:01+00:00 Vitaly Chikunov vt@altlinux.org 2019-12-24T17:20:29+00:00 efc469175fc69710e27928733372e6c57456bfe6 commit 6c4798d3f08b81c2c52936b10e0fa872590c96ae upstream. Disable a couple of compilation warnings (which are treated as errors) on strlcpy() definition and declaration, allowing users to compile perf and kernel (objtool) when: 1. glibc have strlcpy() (such as in ALT Linux since 2004) objtool and perf build fails with this (in gcc): In file included from exec-cmd.c:3: tools/include/linux/string.h:20:15: error: redundant redeclaration of ‘strlcpy’ [-Werror=redundant-decls] 20 | extern size_t strlcpy(char *dest, const char *src, size_t size); 2. clang ignores `-Wredundant-decls', but produces another warning when building perf: CC util/string.o ../lib/string.c:99:8: error: attribute declaration must precede definition [-Werror,-Wignored-attributes] size_t __weak strlcpy(char *dest, const char *src, size_t size) ../../tools/include/linux/compiler.h:66:34: note: expanded from macro '__weak' # define __weak __attribute__((weak)) /usr/include/bits/string_fortified.h:151:8: note: previous definition is here __NTH (strlcpy (char *__restrict __dest, const char *__restrict __src, Committer notes: The #pragma GCC diagnostic directive was introduced in gcc 4.6, so check for that as well. Fixes: ce99091 ("perf tools: Move strlcpy() from perf to tools/lib/string.c") Fixes: 0215d59 ("tools lib: Reinstate strlcpy() header guard with __UCLIBC__") Resolves: https://bugzilla.kernel.org/show_bug.cgi?id=118481 Signed-off-by: Vitaly Chikunov <vt@altlinux.org> Reviewed-by: Dmitry Levin <ldv@altlinux.org> Cc: Dmitry Levin <ldv@altlinux.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: kbuild test robot <lkp@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org Cc: Vineet Gupta <vineet.gupta1@synopsys.com> Link: http://lore.kernel.org/lkml/20191224172029.19690-1-vt@altlinux.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 6c4798d3f08b81c2c52936b10e0fa872590c96ae upstream.

Disable a couple of compilation warnings (which are treated as errors)
on strlcpy() definition and declaration, allowing users to compile perf
and kernel (objtool) when:

1. glibc have strlcpy() (such as in ALT Linux since 2004) objtool and
   perf build fails with this (in gcc):

  In file included from exec-cmd.c:3:
  tools/include/linux/string.h:20:15: error: redundant redeclaration of ‘strlcpy’ [-Werror=redundant-decls]
     20 | extern size_t strlcpy(char *dest, const char *src, size_t size);

2. clang ignores `-Wredundant-decls', but produces another warning when
   building perf:

    CC       util/string.o
  ../lib/string.c:99:8: error: attribute declaration must precede definition [-Werror,-Wignored-attributes]
  size_t __weak strlcpy(char *dest, const char *src, size_t size)
  ../../tools/include/linux/compiler.h:66:34: note: expanded from macro '__weak'
  # define __weak                 __attribute__((weak))
  /usr/include/bits/string_fortified.h:151:8: note: previous definition is here
  __NTH (strlcpy (char *__restrict __dest, const char *__restrict __src,

Committer notes:

The

 #pragma GCC diagnostic

directive was introduced in gcc 4.6, so check for that as well.

Fixes: ce99091 ("perf tools: Move strlcpy() from perf to tools/lib/string.c")
Fixes: 0215d59 ("tools lib: Reinstate strlcpy() header guard with __UCLIBC__")
Resolves: https://bugzilla.kernel.org/show_bug.cgi?id=118481
Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Reviewed-by: Dmitry Levin <ldv@altlinux.org>
Cc: Dmitry Levin <ldv@altlinux.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: kbuild test robot <lkp@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Cc: Vineet Gupta <vineet.gupta1@synopsys.com>
Link: http://lore.kernel.org/lkml/20191224172029.19690-1-vt@altlinux.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-01-18T20:55:19+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-01-18T20:55:19+00:00 b07b9e8d631856c9e42af79900527509449206f4 Pull perf fixes from Ingo Molnar: "Tooling fixes, three Intel uncore driver fixes, plus an AUX events fix uncovered by the perf fuzzer" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel/uncore: Remove PCIe3 unit for SNR perf/x86/intel/uncore: Fix missing marker for snr_uncore_imc_freerunning_events perf/x86/intel/uncore: Add PCI ID of IMC for Xeon E3 V5 Family perf: Correctly handle failed perf_get_aux_event() perf hists: Fix variable name's inconsistency in hists__for_each() macro perf map: Set kmap->kmaps backpointer for main kernel map chunks perf report: Fix incorrectly added dimensions as switch perf data file tools lib traceevent: Fix memory leakage in filter_event 
Pull perf fixes from Ingo Molnar:
 "Tooling fixes, three Intel uncore driver fixes, plus an AUX events fix
  uncovered by the perf fuzzer"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel/uncore: Remove PCIe3 unit for SNR
  perf/x86/intel/uncore: Fix missing marker for snr_uncore_imc_freerunning_events
  perf/x86/intel/uncore: Add PCI ID of IMC for Xeon E3 V5 Family
  perf: Correctly handle failed perf_get_aux_event()
  perf hists: Fix variable name's inconsistency in hists__for_each() macro
  perf map: Set kmap->kmaps backpointer for main kernel map chunks
  perf report: Fix incorrectly added dimensions as switch perf data file
  tools lib traceevent: Fix memory leakage in filter_event
libbpf: Fix build on read-only filesystems 2019-12-23T14:34:06+00:00 Namhyung Kim namhyung@kernel.org 2019-12-23T06:13:26+00:00 fa633a0f89192379828103957874682d389eae83 I got the following error when I tried to build perf on a read-only filesystem with O=dir option. $ cd /some/where/ro/linux/tools/perf $ make O=$HOME/build/perf ... CC /home/namhyung/build/perf/lib.o /bin/sh: bpf_helper_defs.h: Read-only file system make[3]: *** [Makefile:184: bpf_helper_defs.h] Error 1 make[2]: *** [Makefile.perf:778: /home/namhyung/build/perf/libbpf.a] Error 2 make[2]: *** Waiting for unfinished jobs.... LD /home/namhyung/build/perf/libperf-in.o AR /home/namhyung/build/perf/libperf.a PERF_VERSION = 5.4.0 make[1]: *** [Makefile.perf:225: sub-make] Error 2 make: *** [Makefile:70: all] Error 2 It was becaused bpf_helper_defs.h was generated in current directory. Move it to OUTPUT directory. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20191223061326.843366-1-namhyung@kernel.org 
I got the following error when I tried to build perf on a read-only
filesystem with O=dir option.

  $ cd /some/where/ro/linux/tools/perf
  $ make O=$HOME/build/perf
  ...
    CC       /home/namhyung/build/perf/lib.o
  /bin/sh: bpf_helper_defs.h: Read-only file system
  make[3]: *** [Makefile:184: bpf_helper_defs.h] Error 1
  make[2]: *** [Makefile.perf:778: /home/namhyung/build/perf/libbpf.a] Error 2
  make[2]: *** Waiting for unfinished jobs....
    LD       /home/namhyung/build/perf/libperf-in.o
    AR       /home/namhyung/build/perf/libperf.a
    PERF_VERSION = 5.4.0
  make[1]: *** [Makefile.perf:225: sub-make] Error 2
  make: *** [Makefile:70: all] Error 2

It was becaused bpf_helper_defs.h was generated in current directory.
Move it to OUTPUT directory.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191223061326.843366-1-namhyung@kernel.org