linux-stable.git/tools/lib/bpf, branch v5.4.76

libbpf: Remove arch-specific include path in Makefile

2020-10-07T06:01:25+00:00

[ Upstream commit 21e9ba5373fc2cec608fd68301a1dbfd14df3172 ]

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
Signed-off-by: Sasha Levin

libbpf: Handle GCC noreturn-turned-volatile quirk

2020-06-24T15:50:43+00:00

[ Upstream commit 32022fd97ed34f6812802bf1288db27c313576f4 ]

Handle a GCC quirk of emitting extra volatile modifier in DWARF (and
subsequently preserved in BTF by pahole) for function pointers marked as
__attribute__((noreturn)). This was the way to mark such functions before GCC
2.5 added noreturn attribute. Drop such func_proto modifiers, similarly to how
it's done for array (also to handle GCC quirk/bug).

Such volatile attribute is emitted by GCC only, so existing selftests can't
express such test. Simple repro is like this (compiled with GCC + BTF
generated by pahole):

  struct my_struct {
      void __attribute__((noreturn)) (*fn)(int);
  };
  struct my_struct a;

Without this fix, output will be:

struct my_struct {
    voidvolatile  (*fn)(int);
};

With the fix:

struct my_struct {
    void (*fn)(int);
};

Fixes: 351131b51c7a ("libbpf: add btf_dump API for BTF-to-C conversion")
Reported-by: Jean-Philippe Brucker 
Signed-off-by: Andrii Nakryiko 
Signed-off-by: Daniel Borkmann 
Tested-by: Jean-Philippe Brucker 
Link: https://lore.kernel.org/bpf/20200610052335.2862559-1-andriin@fb.com
Signed-off-by: Sasha Levin

libbpf: Fix perf_buffer__free() API for sparse allocs

2020-06-22T07:31:11+00:00

[ Upstream commit 601b05ca6edb0422bf6ce313fbfd55ec7bbbc0fd ]

In case the cpu_bufs are sparsely allocated they are not all
free'ed. These changes will fix this.

Fixes: fb84b8224655 ("libbpf: add perf buffer API")
Signed-off-by: Eelco Chaudron 
Signed-off-by: Daniel Borkmann 
Acked-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/159056888305.330763.9684536967379110349.stgit@ebuild
Signed-off-by: Alexei Starovoitov 
Signed-off-by: Sasha Levin

libbpf: Fix memory leak and possible double-free in hashmap__clear

2020-06-22T07:30:51+00:00

[ Upstream commit 229bf8bf4d910510bc1a2fd0b89bd467cd71050d ]

Fix memory leak in hashmap_clear() not freeing hashmap_entry structs for each
of the remaining entries. Also NULL-out bucket list to prevent possible
double-free between hashmap__clear() and hashmap__free().

Running test_progs-asan flavor clearly showed this problem.

Reported-by: Alston Tang 
Signed-off-by: Andrii Nakryiko 
Signed-off-by: Alexei Starovoitov 
Link: https://lore.kernel.org/bpf/20200429012111.277390-5-andriin@fb.com
Signed-off-by: Sasha Levin

libbpf: Extract and generalize CPU mask parsing logic

2020-05-20T06:20:40+00:00

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 
Signed-off-by: Alexei Starovoitov 
Link: https://lore.kernel.org/bpf/20191212013548.1690564-1-andriin@fb.com
Signed-off-by: Greg Kroah-Hartman

libbpf: Fix readelf output parsing for Fedora

2020-05-10T08:31:32+00:00

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 
Signed-off-by: Thadeu Lima de Souza Cascardo 
Signed-off-by: Alexei Starovoitov 
Acked-by: Andrii Nakryiko 
Cc: Aurelien Jarno 
Link: https://lore.kernel.org/bpf/20191213101114.GA3986@calabresa
Signed-off-by: Greg Kroah-Hartman

libbpf: Initialize *nl_pid so gcc 10 is happy

2020-05-02T06:48:55+00:00

[ Upstream commit 4734b0fefbbf98f8c119eb8344efa19dac82cd2c ]

Builds of Fedora's kernel-tools package started to fail with "may be
used uninitialized" warnings for nl_pid in bpf_set_link_xdp_fd() and
bpf_get_link_xdp_info() on the s390 architecture.

Although libbpf_netlink_open() always returns a negative number when it
does not set *nl_pid, the compiler does not determine this and thus
believes the variable might be used uninitialized. Assuage gcc's fears
by explicitly initializing nl_pid.

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1807781

Signed-off-by: Jeremy Cline 
Signed-off-by: Daniel Borkmann 
Acked-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20200404051430.698058-1-jcline@redhat.com
Signed-off-by: Sasha Levin

libbpf: Fix readelf output parsing on powerpc with recent binutils

2020-04-29T14:33:04+00:00

[ Upstream commit 3464afdf11f9a1e031e7858a05351ceca1792fea ]

On powerpc with recent versions of binutils, readelf outputs an extra
field when dumping the symbols of an object file. For example:

    35: 0000000000000838    96 FUNC    LOCAL  DEFAULT [: 8]     1 btf_is_struct

The extra "[: 8]" prevents the GLOBAL_SYM_COUNT variable to
be computed correctly and causes the check_abi target to fail.

Fix that by looking for the symbol name in the last field instead of the
8th one. This way it should also cope with future extra fields.

Signed-off-by: Aurelien Jarno 
Signed-off-by: Daniel Borkmann 
Tested-by: Michael Ellerman 
Link: https://lore.kernel.org/bpf/20191201195728.4161537-1-aurelien@aurel32.net
Signed-off-by: Sasha Levin

libbpf: Fix realloc usage in bpf_core_find_cands

2020-02-11T12:35:29+00:00

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 
Signed-off-by: Andrii Nakryiko 
Signed-off-by: Daniel Borkmann 
Acked-by: Yonghong Song 
Link: https://lore.kernel.org/bpf/20200124201847.212528-1-andriin@fb.com
Signed-off-by: Greg Kroah-Hartman

libbpf: Don't use kernel-side u32 type in xsk.c

2020-01-26T09:01:05+00:00

[ Upstream commit a566e35f1e8b4b3be1e96a804d1cca38b578167c ]

u32 is a kernel-side typedef. User-space library is supposed to use __u32.
This breaks Github's projection of libbpf. Do u32 -> __u32 fix.

Fixes: 94ff9ebb49a5 ("libbpf: Fix compatibility for kernels without need_wakeup")
Signed-off-by: Andrii Nakryiko 
Signed-off-by: Alexei Starovoitov 
Acked-by: Björn Töpel 
Cc: Magnus Karlsson 
Link: https://lore.kernel.org/bpf/20191029055953.2461336-1-andriin@fb.com
Signed-off-by: Sasha Levin