Commit Graph

2413 Commits

Author SHA1 Message Date
Eduard Zingerman
de048b6ee8 libbpf: Resolve enum fwd as full enum64 and vice versa
Changes de-duplication logic for enums in the following way:
- update btf_hash_enum to ignore size and kind fields to get
  ENUM and ENUM64 types in a same hash bucket;
- update btf_compat_enum to consider enum fwd to be compatible with
  full enum64 (and vice versa);

This allows BTF de-duplication in the following case:

    // CU #1
    enum foo;

    struct s {
      enum foo *a;
    } *x;

    // CU #2
    enum foo {
      x = 0xfffffffff // big enough to force enum64
    };

    struct s {
      enum foo *a;
    } *y;

De-duplicated BTF prior to this commit:

    [1] ENUM64 'foo' encoding=UNSIGNED size=8 vlen=1
    	'x' val=68719476735ULL
    [2] INT 'long unsigned int' size=8 bits_offset=0 nr_bits=64
        encoding=(none)
    [3] STRUCT 's' size=8 vlen=1
    	'a' type_id=4 bits_offset=0
    [4] PTR '(anon)' type_id=1
    [5] PTR '(anon)' type_id=3
    [6] STRUCT 's' size=8 vlen=1
    	'a' type_id=8 bits_offset=0
    [7] ENUM 'foo' encoding=UNSIGNED size=4 vlen=0
    [8] PTR '(anon)' type_id=7
    [9] PTR '(anon)' type_id=6

De-duplicated BTF after this commit:

    [1] ENUM64 'foo' encoding=UNSIGNED size=8 vlen=1
    	'x' val=68719476735ULL
    [2] INT 'long unsigned int' size=8 bits_offset=0 nr_bits=64
        encoding=(none)
    [3] STRUCT 's' size=8 vlen=1
    	'a' type_id=4 bits_offset=0
    [4] PTR '(anon)' type_id=1
    [5] PTR '(anon)' type_id=3

Enum forward declarations in C do not provide information about
enumeration values range. Thus the `btf_type->size` field is
meaningless for forward enum declarations. In fact, GCC does not
encode size in DWARF for forward enum declarations
(but dwarves sets enumeration size to a default value of `sizeof(int) * 8`
when size is not specified see dwarf_loader.c:die__create_new_enumeration).

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221101235413.1824260-1-eddyz87@gmail.com
2022-11-04 13:10:45 -07:00
Jakub Kicinski
b54a0d4094 Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
bpf-next 2022-11-02

We've added 70 non-merge commits during the last 14 day(s) which contain
a total of 96 files changed, 3203 insertions(+), 640 deletions(-).

The main changes are:

1) Make cgroup local storage available to non-cgroup attached BPF programs
   such as tc BPF ones, from Yonghong Song.

2) Avoid unnecessary deadlock detection and failures wrt BPF task storage
   helpers, from Martin KaFai Lau.

3) Add LLVM disassembler as default library for dumping JITed code
   in bpftool, from Quentin Monnet.

4) Various kprobe_multi_link fixes related to kernel modules,
   from Jiri Olsa.

5) Optimize x86-64 JIT with emitting BMI2-based shift instructions,
   from Jie Meng.

6) Improve BPF verifier's memory type compatibility for map key/value
   arguments, from Dave Marchevsky.

7) Only create mmap-able data section maps in libbpf when data is exposed
   via skeletons, from Andrii Nakryiko.

8) Add an autoattach option for bpftool to load all object assets,
   from Wang Yufen.

9) Various memory handling fixes for libbpf and BPF selftests,
   from Xu Kuohai.

10) Initial support for BPF selftest's vmtest.sh on arm64,
    from Manu Bretelle.

11) Improve libbpf's BTF handling to dedup identical structs,
    from Alan Maguire.

12) Add BPF CI and denylist documentation for BPF selftests,
    from Daniel Müller.

13) Check BPF cpumap max_entries before doing allocation work,
    from Florian Lehner.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (70 commits)
  samples/bpf: Fix typo in README
  bpf: Remove the obsolte u64_stats_fetch_*_irq() users.
  bpf: check max_entries before allocating memory
  bpf: Fix a typo in comment for DFS algorithm
  bpftool: Fix spelling mistake "disasembler" -> "disassembler"
  selftests/bpf: Fix bpftool synctypes checking failure
  selftests/bpf: Panic on hard/soft lockup
  docs/bpf: Add documentation for new cgroup local storage
  selftests/bpf: Add test cgrp_local_storage to DENYLIST.s390x
  selftests/bpf: Add selftests for new cgroup local storage
  selftests/bpf: Fix test test_libbpf_str/bpf_map_type_str
  bpftool: Support new cgroup local storage
  libbpf: Support new cgroup local storage
  bpf: Implement cgroup storage available to non-cgroup-attached bpf progs
  bpf: Refactor some inode/task/sk storage functions for reuse
  bpf: Make struct cgroup btf id global
  selftests/bpf: Tracing prog can still do lookup under busy lock
  selftests/bpf: Ensure no task storage failure for bpf_lsm.s prog due to deadlock detection
  bpf: Add new bpf_task_storage_delete proto with no deadlock detection
  bpf: bpf_task_storage_delete_recur does lookup first before the deadlock check
  ...
====================

Link: https://lore.kernel.org/r/20221102062120.5724-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-02 08:18:27 -07:00
Yonghong Song
4fe64af23c libbpf: Support new cgroup local storage
Add support for new cgroup local storage.

Acked-by: David Vernet <void@manifault.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221026042856.673989-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-10-25 23:19:19 -07:00
Alan Maguire
f3c51fe02c libbpf: Btf dedup identical struct test needs check for nested structs/arrays
When examining module BTF, it is common to see core kernel structures
such as sk_buff, net_device duplicated in the module.  After adding
debug messaging to BTF it turned out that much of the problem
was down to the identical struct test failing during deduplication;
sometimes the compiler adds identical structs.  However
it turns out sometimes that type ids of identical struct members
can also differ, even when the containing structs are still identical.

To take an example, for struct sk_buff, debug messaging revealed
that the identical struct matching was failing for the anon
struct "headers"; specifically for the first field:

__u8       __pkt_type_offset[0]; /*   128     0 */

Looking at the code in BTF deduplication, we have code that guards
against the possibility of identical struct definitions, down to
type ids, and identical array definitions.  However in this case
we have a struct which is being defined twice but does not have
identical type ids since each duplicate struct has separate type
ids for the above array member.   A similar problem (though not
observed) could occur for struct-in-struct.

The solution is to make the "identical struct" test check members
not just for matching ids, but to also check if they in turn are
identical structs or arrays.

The results of doing this are quite dramatic (for some modules
at least); I see the number of type ids drop from around 10000
to just over 1000 in one module for example.

For testing use latest pahole or apply [1], otherwise dedups
can fail for the reasons described there.

Also fix return type of btf_dedup_identical_arrays() as
suggested by Andrii to match boolean return type used
elsewhere.

Fixes: efdd3eb801 ("libbpf: Accommodate DWARF/compiler bug with duplicated structs")
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1666622309-22289-1-git-send-email-alan.maguire@oracle.com

[1] https://lore.kernel.org/bpf/1666364523-9648-1-git-send-email-alan.maguire
2022-10-25 16:16:14 -07:00
Xu Kuohai
d9740535b8 libbpf: Avoid allocating reg_name with sscanf in parse_usdt_arg()
The reg_name in parse_usdt_arg() is used to hold register name, which
is short enough to be held in a 16-byte array, so we could define
reg_name as char reg_name[16] to avoid dynamically allocating reg_name
with sscanf.

Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20221018145538.2046842-1-xukuohai@huaweicloud.com
2022-10-21 14:28:14 -07:00
Jakub Kicinski
94adb5e29e Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
No conflicts.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-20 17:49:10 -07:00
Andrii Nakryiko
4fcac46c7e libbpf: only add BPF_F_MMAPABLE flag for data maps with global vars
Teach libbpf to not add BPF_F_MMAPABLE flag unnecessarily for ARRAY maps
that are backing data sections, if such data sections don't expose any
variables to user-space. Exposed variables are those that have
STB_GLOBAL or STB_WEAK ELF binding and correspond to BTF VAR's
BTF_VAR_GLOBAL_ALLOCATED linkage.

The overall idea is that if some data section doesn't have any variable that
is exposed through BPF skeleton, then there is no reason to make such
BPF array mmapable. Making BPF array mmapable is not a free no-op
action, because BPF verifier doesn't allow users to put special objects
(such as BPF spin locks, RB tree nodes, linked list nodes, kptrs, etc;
anything that has a sensitive internal state that should not be modified
arbitrarily from user space) into mmapable arrays, as there is no way to
prevent user space from corrupting such sensitive state through direct
memory access through memory-mapped region.

By making sure that libbpf doesn't add BPF_F_MMAPABLE flag to BPF array
maps corresponding to data sections that only have static variables
(which are not supposed to be visible to user space according to libbpf
and BPF skeleton rules), users now can have spinlocks, kptrs, etc in
either default .bss/.data sections or custom .data.* sections (assuming
there are no global variables in such sections).

The only possible hiccup with this approach is the need to use global
variables during BPF static linking, even if it's not intended to be
shared with user space through BPF skeleton. To allow such scenarios,
extend libbpf's STV_HIDDEN ELF visibility attribute handling to
variables. Libbpf is already treating global hidden BPF subprograms as
static subprograms and adjusts BTF accordingly to make BPF verifier
verify such subprograms as static subprograms with preserving entire BPF
verifier state between subprog calls. This patch teaches libbpf to treat
global hidden variables as static ones and adjust BTF information
accordingly as well. This allows to share variables between multiple
object files during static linking, but still keep them internal to BPF
program and not get them exposed through BPF skeleton.

Note, that if the user has some advanced scenario where they absolutely
need BPF_F_MMAPABLE flag on .data/.bss/.rodata BPF array map despite
only having static variables, they still can achieve this by forcing it
through explicit bpf_map__set_map_flags() API.

Acked-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20221019002816.359650-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-10-19 16:40:45 -07:00
Andrii Nakryiko
f33f742d56 libbpf: clean up and refactor BTF fixup step
Refactor libbpf's BTF fixup step during BPF object open phase. The only
functional change is that we now ignore BTF_VAR_GLOBAL_EXTERN variables
during fix up, not just BTF_VAR_STATIC ones, which shouldn't cause any
change in behavior as there shouldn't be any extern variable in data
sections for valid BPF object anyways.

Otherwise it's just collapsing two functions that have no reason to be
separate, and switching find_elf_var_offset() helper to return entire
symbol pointer, not just its offset. This will be used by next patch to
get ELF symbol visibility.

While refactoring, also "normalize" debug messages inside
btf_fixup_datasec() to follow general libbpf style and print out data
section name consistently, where it's available.

Acked-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221019002816.359650-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-10-19 16:40:45 -07:00
Jakub Kicinski
3566a79c9e Merge tag 'for-netdev' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2022-10-18

We've added 33 non-merge commits during the last 14 day(s) which contain
a total of 31 files changed, 874 insertions(+), 538 deletions(-).

The main changes are:

1) Add RCU grace period chaining to BPF to wait for the completion
   of access from both sleepable and non-sleepable BPF programs,
   from Hou Tao & Paul E. McKenney.

2) Improve helper UAPI by explicitly defining BPF_FUNC_xxx integer
   values. In the wild we have seen OS vendors doing buggy backports
   where helper call numbers mismatched. This is an attempt to make
   backports more foolproof, from Andrii Nakryiko.

3) Add libbpf *_opts API-variants for bpf_*_get_fd_by_id() functions,
   from Roberto Sassu.

4) Fix libbpf's BTF dumper for structs with padding-only fields,
   from Eduard Zingerman.

5) Fix various libbpf bugs which have been found from fuzzing with
   malformed BPF object files, from Shung-Hsi Yu.

6) Clean up an unneeded check on existence of SSE2 in BPF x86-64 JIT,
   from Jie Meng.

7) Fix various ASAN bugs in both libbpf and selftests when running
   the BPF selftest suite on arm64, from Xu Kuohai.

8) Fix missing bpf_iter_vma_offset__destroy() call in BPF iter selftest
   and use in-skeleton link pointer to remove an explicit bpf_link__destroy(),
   from Jiri Olsa.

9) Fix BPF CI breakage by pointing to iptables-legacy instead of relying
   on symlinked iptables which got upgraded to iptables-nft,
   from Martin KaFai Lau.

10) Minor BPF selftest improvements all over the place, from various others.

* tag 'for-netdev' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (33 commits)
  bpf/docs: Update README for most recent vmtest.sh
  bpf: Use rcu_trace_implies_rcu_gp() for program array freeing
  bpf: Use rcu_trace_implies_rcu_gp() in local storage map
  bpf: Use rcu_trace_implies_rcu_gp() in bpf memory allocator
  rcu-tasks: Provide rcu_trace_implies_rcu_gp()
  selftests/bpf: Use sys_pidfd_open() helper when possible
  libbpf: Fix null-pointer dereference in find_prog_by_sec_insn()
  libbpf: Deal with section with no data gracefully
  libbpf: Use elf_getshdrnum() instead of e_shnum
  selftest/bpf: Fix error usage of ASSERT_OK in xdp_adjust_tail.c
  selftests/bpf: Fix error failure of case test_xdp_adjust_tail_grow
  selftest/bpf: Fix memory leak in kprobe_multi_test
  selftests/bpf: Fix memory leak caused by not destroying skeleton
  libbpf: Fix memory leak in parse_usdt_arg()
  libbpf: Fix use-after-free in btf_dump_name_dups
  selftests/bpf: S/iptables/iptables-legacy/ in the bpf_nf and xdp_synproxy test
  selftests/bpf: Alphabetize DENYLISTs
  selftests/bpf: Add tests for _opts variants of bpf_*_get_fd_by_id()
  libbpf: Introduce bpf_link_get_fd_by_id_opts()
  libbpf: Introduce bpf_btf_get_fd_by_id_opts()
  ...
====================

Link: https://lore.kernel.org/r/20221018210631.11211-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-18 18:56:43 -07:00
Arnaldo Carvalho de Melo
d5e57375a5 libperf: Do not include non-UAPI linux/compiler.h header
Its just for that __packed define, so use it expanded as __attribute__((packed)),
like the other files in /usr/include do.

This was problem was preventing building the libperf examples on ALT
Linux and Fedora 35, fix it.

Reported-by: Vitaly Chikunov <vt@altlinux.org>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Dmitry Levin <ldv@altlinux.org
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/Y0lnpl2Ix7VljVDc@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-10-14 10:44:20 -03:00
Shung-Hsi Yu
d0d382f95a libbpf: Fix null-pointer dereference in find_prog_by_sec_insn()
When there are no program sections, obj->programs is left unallocated,
and find_prog_by_sec_insn()'s search lands on &obj->programs[0] == NULL,
and will cause null-pointer dereference in the following access to
prog->sec_idx.

Guard the search with obj->nr_programs similar to what's being done in
__bpf_program__iter() to prevent null-pointer access from happening.

Fixes: db2b8b0642 ("libbpf: Support CO-RE relocations for multi-prog sections")
Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221012022353.7350-4-shung-hsi.yu@suse.com
2022-10-13 10:53:34 -07:00
Shung-Hsi Yu
35a855509e libbpf: Deal with section with no data gracefully
ELF section data pointer returned by libelf may be NULL (if section has
SHT_NOBITS), so null check section data pointer before attempting to
copy license and kversion section.

Fixes: cb1e5e9619 ("bpf tools: Collect version and license from ELF sections")
Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221012022353.7350-3-shung-hsi.yu@suse.com
2022-10-13 10:53:34 -07:00
Shung-Hsi Yu
51deedc9b8 libbpf: Use elf_getshdrnum() instead of e_shnum
This commit replace e_shnum with the elf_getshdrnum() helper to fix two
oss-fuzz-reported heap-buffer overflow in __bpf_object__open. Both
reports are incorrectly marked as fixed and while still being
reproducible in the latest libbpf.

  # clusterfuzz-testcase-minimized-bpf-object-fuzzer-5747922482888704
  libbpf: loading object 'fuzz-object' from buffer
  libbpf: sec_cnt is 0
  libbpf: elf: section(1) .data, size 0, link 538976288, flags 2020202020202020, type=2
  libbpf: elf: section(2) .data, size 32, link 538976288, flags 202020202020ff20, type=1
  =================================================================
  ==13==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x6020000000c0 at pc 0x0000005a7b46 bp 0x7ffd12214af0 sp 0x7ffd12214ae8
  WRITE of size 4 at 0x6020000000c0 thread T0
  SCARINESS: 46 (4-byte-write-heap-buffer-overflow-far-from-bounds)
      #0 0x5a7b45 in bpf_object__elf_collect /src/libbpf/src/libbpf.c:3414:24
      #1 0x5733c0 in bpf_object_open /src/libbpf/src/libbpf.c:7223:16
      #2 0x5739fd in bpf_object__open_mem /src/libbpf/src/libbpf.c:7263:20
      ...

The issue lie in libbpf's direct use of e_shnum field in ELF header as
the section header count. Where as libelf implemented an extra logic
that, when e_shnum == 0 && e_shoff != 0, will use sh_size member of the
initial section header as the real section header count (part of ELF
spec to accommodate situation where section header counter is larger
than SHN_LORESERVE).

The above inconsistency lead to libbpf writing into a zero-entry calloc
area. So intead of using e_shnum directly, use the elf_getshdrnum()
helper provided by libelf to retrieve the section header counter into
sec_cnt.

Fixes: 0d6988e16a ("libbpf: Fix section counting logic")
Fixes: 25bbbd7a44 ("libbpf: Remove assumptions about uniqueness of .rodata/.data/.bss maps")
Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=40868
Link: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=40957
Link: https://lore.kernel.org/bpf/20221012022353.7350-2-shung-hsi.yu@suse.com
2022-10-13 10:53:34 -07:00
Xu Kuohai
0dc9254e03 libbpf: Fix memory leak in parse_usdt_arg()
In the arm64 version of parse_usdt_arg(), when sscanf returns 2, reg_name
is allocated but not freed. Fix it.

Fixes: 0f8619929c ("libbpf: Usdt aarch64 arg parsing support")
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/bpf/20221011120108.782373-3-xukuohai@huaweicloud.com
2022-10-13 10:53:18 -07:00
Xu Kuohai
93c660ca40 libbpf: Fix use-after-free in btf_dump_name_dups
ASAN reports an use-after-free in btf_dump_name_dups:

ERROR: AddressSanitizer: heap-use-after-free on address 0xffff927006db at pc 0xaaaab5dfb618 bp 0xffffdd89b890 sp 0xffffdd89b928
READ of size 2 at 0xffff927006db thread T0
    #0 0xaaaab5dfb614 in __interceptor_strcmp.part.0 (test_progs+0x21b614)
    #1 0xaaaab635f144 in str_equal_fn tools/lib/bpf/btf_dump.c:127
    #2 0xaaaab635e3e0 in hashmap_find_entry tools/lib/bpf/hashmap.c:143
    #3 0xaaaab635e72c in hashmap__find tools/lib/bpf/hashmap.c:212
    #4 0xaaaab6362258 in btf_dump_name_dups tools/lib/bpf/btf_dump.c:1525
    #5 0xaaaab636240c in btf_dump_resolve_name tools/lib/bpf/btf_dump.c:1552
    #6 0xaaaab6362598 in btf_dump_type_name tools/lib/bpf/btf_dump.c:1567
    #7 0xaaaab6360b48 in btf_dump_emit_struct_def tools/lib/bpf/btf_dump.c:912
    #8 0xaaaab6360630 in btf_dump_emit_type tools/lib/bpf/btf_dump.c:798
    #9 0xaaaab635f720 in btf_dump__dump_type tools/lib/bpf/btf_dump.c:282
    #10 0xaaaab608523c in test_btf_dump_incremental tools/testing/selftests/bpf/prog_tests/btf_dump.c:236
    #11 0xaaaab6097530 in test_btf_dump tools/testing/selftests/bpf/prog_tests/btf_dump.c:875
    #12 0xaaaab6314ed0 in run_one_test tools/testing/selftests/bpf/test_progs.c:1062
    #13 0xaaaab631a0a8 in main tools/testing/selftests/bpf/test_progs.c:1697
    #14 0xffff9676d214 in __libc_start_main ../csu/libc-start.c:308
    #15 0xaaaab5d65990  (test_progs+0x185990)

0xffff927006db is located 11 bytes inside of 16-byte region [0xffff927006d0,0xffff927006e0)
freed by thread T0 here:
    #0 0xaaaab5e2c7c4 in realloc (test_progs+0x24c7c4)
    #1 0xaaaab634f4a0 in libbpf_reallocarray tools/lib/bpf/libbpf_internal.h:191
    #2 0xaaaab634f840 in libbpf_add_mem tools/lib/bpf/btf.c:163
    #3 0xaaaab636643c in strset_add_str_mem tools/lib/bpf/strset.c:106
    #4 0xaaaab6366560 in strset__add_str tools/lib/bpf/strset.c:157
    #5 0xaaaab6352d70 in btf__add_str tools/lib/bpf/btf.c:1519
    #6 0xaaaab6353e10 in btf__add_field tools/lib/bpf/btf.c:2032
    #7 0xaaaab6084fcc in test_btf_dump_incremental tools/testing/selftests/bpf/prog_tests/btf_dump.c:232
    #8 0xaaaab6097530 in test_btf_dump tools/testing/selftests/bpf/prog_tests/btf_dump.c:875
    #9 0xaaaab6314ed0 in run_one_test tools/testing/selftests/bpf/test_progs.c:1062
    #10 0xaaaab631a0a8 in main tools/testing/selftests/bpf/test_progs.c:1697
    #11 0xffff9676d214 in __libc_start_main ../csu/libc-start.c:308
    #12 0xaaaab5d65990  (test_progs+0x185990)

previously allocated by thread T0 here:
    #0 0xaaaab5e2c7c4 in realloc (test_progs+0x24c7c4)
    #1 0xaaaab634f4a0 in libbpf_reallocarray tools/lib/bpf/libbpf_internal.h:191
    #2 0xaaaab634f840 in libbpf_add_mem tools/lib/bpf/btf.c:163
    #3 0xaaaab636643c in strset_add_str_mem tools/lib/bpf/strset.c:106
    #4 0xaaaab6366560 in strset__add_str tools/lib/bpf/strset.c:157
    #5 0xaaaab6352d70 in btf__add_str tools/lib/bpf/btf.c:1519
    #6 0xaaaab6353ff0 in btf_add_enum_common tools/lib/bpf/btf.c:2070
    #7 0xaaaab6354080 in btf__add_enum tools/lib/bpf/btf.c:2102
    #8 0xaaaab6082f50 in test_btf_dump_incremental tools/testing/selftests/bpf/prog_tests/btf_dump.c:162
    #9 0xaaaab6097530 in test_btf_dump tools/testing/selftests/bpf/prog_tests/btf_dump.c:875
    #10 0xaaaab6314ed0 in run_one_test tools/testing/selftests/bpf/test_progs.c:1062
    #11 0xaaaab631a0a8 in main tools/testing/selftests/bpf/test_progs.c:1697
    #12 0xffff9676d214 in __libc_start_main ../csu/libc-start.c:308
    #13 0xaaaab5d65990  (test_progs+0x185990)

The reason is that the key stored in hash table name_map is a string
address, and the string memory is allocated by realloc() function, when
the memory is resized by realloc() later, the old memory may be freed,
so the address stored in name_map references to a freed memory, causing
use-after-free.

Fix it by storing duplicated string address in name_map.

Fixes: 919d2b1dbb ("libbpf: Allow modification of BTF and add btf__add_str API")
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/bpf/20221011120108.782373-2-xukuohai@huaweicloud.com
2022-10-13 10:53:03 -07:00
Linus Torvalds
d465bff130 Merge tag 'perf-tools-for-v6.1-1-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux
Pull perf tools updates from Arnaldo Carvalho de Melo:

 - Add support for AMD on 'perf mem' and 'perf c2c', the kernel
   enablement patches went via tip.

   Example:

      $ sudo perf mem record -- -c 10000
      ^C[ perf record: Woken up 227 times to write data ]
      [ perf record: Captured and wrote 58.760 MB perf.data (836978 samples) ]

      $ sudo perf mem report -F mem,sample,snoop
      Samples: 836K of event 'ibs_op//', Event count (approx.): 8418762
      Memory access                  Samples  Snoop
      N/A                             700620  N/A
      L1 hit                          126675  N/A
      L2 hit                             424  N/A
      L3 hit                             664  HitM
      L3 hit                              10  N/A
      Local RAM hit                        2  N/A
      Remote RAM (1 hop) hit            8558  N/A
      Remote Cache (1 hop) hit             3  N/A
      Remote Cache (1 hop) hit             2  HitM
      Remote Cache (2 hops) hit           10  HitM
      Remote Cache (2 hops) hit            6  N/A
      Uncached hit                         4  N/A
      $

 - "perf lock" improvements:

     - Add -E/--entries option to limit the number of entries to
       display, say to ask for just the top 5 contended locks.

     - Add -q/--quiet option to suppress header and debug messages.

     - Add a 'perf test' kernel lock contention entry to test 'perf
       lock'.

 - "perf lock contention" improvements:

     - Ask BPF's bpf_get_stackid() to skip some callchain entries.

       The ones closer to the tooling are bpf related and not that
       interesting, the ones calling the locking function are the ones
       we're interested in, example of a full, unskipped callstack:

     - Allow changing the callstack depth and number of entries to skip.

           1     10.74 us     10.74 us     10.74 us     spinlock   __bpf_trace_contention_begin+0xb
                          0xffffffffc03b5c47  bpf_prog_bf07ae9e2cbd02c5_contention_begin+0x117
                          0xffffffffc03b5c47  bpf_prog_bf07ae9e2cbd02c5_contention_begin+0x117
                          0xffffffffbb8b8e75  bpf_trace_run2+0x35
                          0xffffffffbb7eab9b  __bpf_trace_contention_begin+0xb
                          0xffffffffbb7ebe75  queued_spin_lock_slowpath+0x1f5
                          0xffffffffbc1c26ff  _raw_spin_lock+0x1f
                          0xffffffffbb841015  tick_do_update_jiffies64+0x25
                          0xffffffffbb8409ee  tick_irq_enter+0x9e

     - Show full callstack in verbose mode (-v option), sometimes this
       is desirable instead of showing just one callstack entry.

 - Allow multiple time ranges in 'perf record --delay' to help in
   reducing the amount of data collected from hardware tracing (Intel
   PT, etc) when there is a rough idea of periods of time where events
   of interest take time.

 - Add Intel PT to record only decoder debug messages when error
   happens.

 - Improve layout of Intel PT man page.

 - Add new branch types: alignment, data and inst faults and arch
   specific ones, such as fiq, debug_halt, debug_exit, debug_inst and
   debug_data on arm64.

   Kernel enablement went thru the tip tree.

 - Fix 'perf probe' error log check in 'perf test' when no debuginfo is
   available.

 - Fix 'perf stat' aggregation mode logic, it should be looking at the
   CPU not at the core number.

 - Fix flags parsing in 'perf trace' filters.

 - Introduce compact encoding of CPU range encoding on perf.data, to
   avoid having a bitmap with all the CPUs.

 - Improvements to the 'perf stat' metrics, including adding
   "core_wide", and computing "smt" from the CPU topology.

 - Add support to the new PERF_FORMAT_LOST perf_event_attr.read_format,
   that allows tooling to ask for the precise number of lost samples for
   a given event.

 - Add 'addr' sort key to see just the address of sampled instructions:

      $ perf record -o- true | perf report -i- -s addr
      [ perf record: Woken up 1 times to write data ]
      [ perf record: Captured and wrote 0.000 MB - ]
      # Samples: 12  of event 'cycles:u'
      # Event count (approx.): 252512
      #
      # Overhead  Address
      # ........  ..................
          42.96%  0x7f96f08443d7
          29.55%  0x7f96f0859b50
          14.76%  0x7f96f0852e02
           8.30%  0x7f96f0855028
           4.43%  0xffffffff8de01087

      perf annotate: Toggle full address <-> offset display

 - Add 'f' hotkey to the 'perf annotate' TUI interface when in
   'disassembler output' mode ('o' hotkey) to toggle showing full
   virtual address or just the offset.

 - Cache DSO build-ids when synthesizing PERF_RECORD_MMAP records for
   pre-existing threads, at the start of a 'perf record' session,
   speeding up that record startup phase.

 - Add a command line option to specify build ids in 'perf inject'.

 - Update JSON event files for the Intel alderlake, broadwell,
   broadwellde, broadwellx, cascadelakex, haswell, haswellx, icelake,
   icelakex, ivybridge, ivytown, jaketown, sandybridge, sapphirerapids,
   skylake, skylakex, and tigerlake processors.

 - Update vendor JSON event files for the ARM Neoverse V1 and E1
   platforms.

 - Add a 'perf test' entry for 'perf mem' where a struct has false
   sharing and this gets detected in the 'perf mem' output, tested with
   Intel, AMD and ARM64 systems.

 - Add a 'perf test' entry to test the resolution of java symbols, where
   an output like this is expected:

       8.18%  jshell    jitted-50116-29.so    [.] Interpreter
       0.75%  Thread-1  jitted-83602-1670.so  [.] jdk.internal.jimage.BasicImageReader.getString(int)

 - Add tests for the ARM64 CoreSight hardware tracing feature, with
   specially crafted pureloop, memcpy, thread loop and unroll tread that
   then gets traced and the output compared with expected output.

   Documentation explaining it is also included.

 - Add per thread Intel PT 'perf test' entry to check that
   PERF_RECORD_TEXT_POKE events are recorded per CPU, resulting in a
   mixture of per thread and per CPU events and mmaps, verify that this
   gets all recorded correctly.

 - Introduce pthread mutex wrappers to allow for building with clang's
   -Wthread-safety, i.e. using the "guarded_by" "pt_guarded_by"
   "lockable", "exclusive_lock_function", "exclusive_trylock_function",
   "exclusive_locks_required", and "no_thread_safety_analysis" compiler
   function attributes.

 - Fix empty version number when building outside of a git repo.

 - Improve feature detection display when multiple versions of a feature
   are present, such as for binutils libbfd, that has a mix of possible
   ways to detect according to the Linux distribution.

   Previously in some cases we had:

      Auto-detecting system features
      <SNIP>
      ...                                  libbfd: [ on  ]
      ...                          libbfd-liberty: [ on  ]
      ...                        libbfd-liberty-z: [ on  ]
      <SNIP>

   Now for this case we show just the main feature:

      Auto-detecting system features
      <SNIP>
      ...                                  libbfd: [ on  ]
      <SNIP>

 - Remove some unused structs, variables, macros, function prototypes
   and includes from various places.

* tag 'perf-tools-for-v6.1-1-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (169 commits)
  perf script: Add missing fields in usage hint
  perf mem: Print "LFB/MAB" for PERF_MEM_LVLNUM_LFB
  perf mem/c2c: Avoid printing empty lines for unsupported events
  perf mem/c2c: Add load store event mappings for AMD
  perf mem/c2c: Set PERF_SAMPLE_WEIGHT for LOAD_STORE events
  perf mem: Add support for printing PERF_MEM_LVLNUM_{CXL|IO}
  perf amd ibs: Sync arch/x86/include/asm/amd-ibs.h header with the kernel
  tools headers UAPI: Sync include/uapi/linux/perf_event.h header with the kernel
  perf stat: Fix cpu check to use id.cpu.cpu in aggr_printout()
  perf test coresight: Add relevant documentation about ARM64 CoreSight testing
  perf test: Add git ignore for tmp and output files of ARM CoreSight tests
  perf test coresight: Add unroll thread test shell script
  perf test coresight: Add unroll thread test tool
  perf test coresight: Add thread loop test shell scripts
  perf test coresight: Add thread loop test tool
  perf test coresight: Add memcpy thread test shell script
  perf test coresight: Add memcpy thread test tool
  perf test: Add git ignore for perf data generated by the ARM CoreSight tests
  perf test: Add arm64 asm pureloop test shell script
  perf test: Add asm pureloop test tool
  ...
2022-10-11 15:02:25 -07:00
Roberto Sassu
97c8f9dd5d libbpf: Introduce bpf_link_get_fd_by_id_opts()
Introduce bpf_link_get_fd_by_id_opts(), for symmetry with
bpf_map_get_fd_by_id_opts(), to let the caller pass the newly introduced
data structure bpf_get_fd_by_id_opts. Keep the existing
bpf_link_get_fd_by_id(), and call bpf_link_get_fd_by_id_opts() with NULL as
opts argument, to prevent setting open_flags.

Currently, the kernel does not support non-zero open_flags for
bpf_link_get_fd_by_id_opts(), and a call with them will result in an error
returned by the bpf() system call. The caller should always pass zero
open_flags.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221006110736.84253-6-roberto.sassu@huaweicloud.com
2022-10-10 16:49:20 -07:00
Roberto Sassu
2ce7cbf2ba libbpf: Introduce bpf_btf_get_fd_by_id_opts()
Introduce bpf_btf_get_fd_by_id_opts(), for symmetry with
bpf_map_get_fd_by_id_opts(), to let the caller pass the newly introduced
data structure bpf_get_fd_by_id_opts. Keep the existing
bpf_btf_get_fd_by_id(), and call bpf_btf_get_fd_by_id_opts() with NULL as
opts argument, to prevent setting open_flags.

Currently, the kernel does not support non-zero open_flags for
bpf_btf_get_fd_by_id_opts(), and a call with them will result in an error
returned by the bpf() system call. The caller should always pass zero
open_flags.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221006110736.84253-5-roberto.sassu@huaweicloud.com
2022-10-10 16:49:20 -07:00
Roberto Sassu
8f13f168ea libbpf: Introduce bpf_prog_get_fd_by_id_opts()
Introduce bpf_prog_get_fd_by_id_opts(), for symmetry with
bpf_map_get_fd_by_id_opts(), to let the caller pass the newly introduced
data structure bpf_get_fd_by_id_opts. Keep the existing
bpf_prog_get_fd_by_id(), and call bpf_prog_get_fd_by_id_opts() with NULL as
opts argument, to prevent setting open_flags.

Currently, the kernel does not support non-zero open_flags for
bpf_prog_get_fd_by_id_opts(), and a call with them will result in an error
returned by the bpf() system call. The caller should always pass zero
open_flags.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221006110736.84253-4-roberto.sassu@huaweicloud.com
2022-10-10 16:49:20 -07:00
Roberto Sassu
243e300563 libbpf: Introduce bpf_get_fd_by_id_opts and bpf_map_get_fd_by_id_opts()
Define a new data structure called bpf_get_fd_by_id_opts, with the member
open_flags, to be used by callers of the _opts variants of
bpf_*_get_fd_by_id() to specify the permissions needed for the file
descriptor to be obtained.

Also, introduce bpf_map_get_fd_by_id_opts(), to let the caller pass a
bpf_get_fd_by_id_opts structure.

Finally, keep the existing bpf_map_get_fd_by_id(), and call
bpf_map_get_fd_by_id_opts() with NULL as opts argument, to request
read-write permissions (current behavior).

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221006110736.84253-3-roberto.sassu@huaweicloud.com
2022-10-10 16:49:20 -07:00
Roberto Sassu
7a366da2d2 libbpf: Fix LIBBPF_1.0.0 declaration in libbpf.map
Add the missing LIBBPF_0.8.0 at the end of the LIBBPF_1.0.0 declaration,
similarly to other version declarations.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221006110736.84253-2-roberto.sassu@huaweicloud.com
2022-10-10 16:49:20 -07:00
Linus Torvalds
d4013bc4d4 Merge tag 'bitmap-6.1-rc1' of https://github.com/norov/linux
Pull bitmap updates from Yury Norov:

 - Fix unsigned comparison to -1 in CPUMAP_FILE_MAX_BYTES (Phil Auld)

 - cleanup nr_cpu_ids vs nr_cpumask_bits mess (me)

   This series cleans that mess and adds new config FORCE_NR_CPUS that
   allows to optimize cpumask subsystem if the number of CPUs is known
   at compile-time.

 - optimize find_bit() functions (me)

   Reworks find_bit() functions based on new FIND_{FIRST,NEXT}_BIT()
   macros.

 - add find_nth_bit() (me)

   Adds find_nth_bit(), which is ~70 times faster than bitcounting with
   for_each() loop:

	for_each_set_bit(bit, mask, size)
		if (n-- == 0)
			return bit;

   Also adds bitmap_weight_and() to let people replace this pattern:

	tmp = bitmap_alloc(nbits);
	bitmap_and(tmp, map1, map2, nbits);
	weight = bitmap_weight(tmp, nbits);
	bitmap_free(tmp);

   with a single bitmap_weight_and() call.

 - repair cpumask_check() (me)

   After switching cpumask to use nr_cpu_ids, cpumask_check() started
   generating many false-positive warnings. This series fixes it.

 - Add for_each_cpu_andnot() and for_each_cpu_andnot() (Valentin
   Schneider)

   Extends the API with one more function and applies it in sched/core.

* tag 'bitmap-6.1-rc1' of https://github.com/norov/linux: (28 commits)
  sched/core: Merge cpumask_andnot()+for_each_cpu() into for_each_cpu_andnot()
  lib/test_cpumask: Add for_each_cpu_and(not) tests
  cpumask: Introduce for_each_cpu_andnot()
  lib/find_bit: Introduce find_next_andnot_bit()
  cpumask: fix checking valid cpu range
  lib/bitmap: add tests for for_each() loops
  lib/find: optimize for_each() macros
  lib/bitmap: introduce for_each_set_bit_wrap() macro
  lib/find_bit: add find_next{,_and}_bit_wrap
  cpumask: switch for_each_cpu{,_not} to use for_each_bit()
  net: fix cpu_max_bits_warn() usage in netif_attrmask_next{,_and}
  cpumask: add cpumask_nth_{,and,andnot}
  lib/bitmap: remove bitmap_ord_to_pos
  lib/bitmap: add tests for find_nth_bit()
  lib: add find_nth{,_and,_andnot}_bit()
  lib/bitmap: add bitmap_weight_and()
  lib/bitmap: don't call __bitmap_weight() in kernel code
  tools: sync find_bit() implementation
  lib/find_bit: optimize find_next_bit() functions
  lib/find_bit: create find_first_zero_bit_le()
  ...
2022-10-10 12:49:34 -07:00
Namhyung Kim
1337b9dcb0 perf tools: Remove special handling of system-wide evsel
For system-wide evsels, the thread map should be dummy - i.e. it has a
single entry of -1.  But the code guarantees such a thread map, so no
need to handle it specially.

No functional change intended.

Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221003204647.1481128-6-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-10-06 08:03:53 -03:00
Namhyung Kim
7e2450bb75 libperf: Propagate maps only if necessary
The current code propagate evsel's cpu map settings to evlist when it's
added to an evlist.  But the evlist->all_cpus and each evsel's cpus will
be updated in perf_evlist__set_maps() later.  No need to do it before
evlist's cpus are set actually.

In fact it discards this intermediate all_cpus maps at the beginning
of perf_evlist__set_maps().  Let's not do this.  It's only needed when
an evsel is added after the evlist cpu/thread maps are set.

Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221003204647.1481128-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-10-06 08:03:53 -03:00
Namhyung Kim
06b552ee37 libperf: Populate system-wide evsel maps
Setting proper cpu and thread maps for system wide evsels regardless of
user requested cpu in __perf_evlist__propagate_maps().  Those evsels
need to be active on all cpus always.  Do it in the libperf so that we
can guarantee it has proper maps.

Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221003204647.1481128-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-10-06 08:03:53 -03:00