Do defensive programming by using zfree() to initialize freed pointers
to NULL, so that eventual use after free result in a NULL pointer deref
instead of more subtle behaviour.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Do defensive programming by using zfree() to initialize freed pointers
to NULL, so that eventual use after free result in a NULL pointer deref
instead of more subtle behaviour.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Do defensive programming by using zfree() to initialize freed pointers
to NULL, so that eventual use after free result in a NULL pointer deref
instead of more subtle behaviour.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Do defensive programming by using zfree() to initialize freed pointers
to NULL, so that eventual use after free result in a NULL pointer deref
instead of more subtle behaviour.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Do defensive programming by using zfree() to initialize freed pointers
to NULL, so that eventual use after free result in a NULL pointer deref
instead of more subtle behaviour.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Do defensive programming by using zfree() to initialize freed pointers
to NULL, so that eventual use after free result in a NULL pointer deref
instead of more subtle behaviour.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Do defensive programming by using zfree() to initialize freed pointers
to NULL, so that eventual use after free result in a NULL pointer deref
instead of more subtle behaviour.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Now that kselftest.h can be used with nolibc convert the za-fork test to
use it. We do still have to open code ksft_print_msg() but that's not the
end of the world. Some of the advantage comes from using printf() which we
could have been using already.
This does change the output when tests are skipped, bringing it in line
with the standard kselftest output by removing the test name - we move
from
ok 0 skipped
to
ok 1 # SKIP fork_test
The old output was not following KTAP format for skips, and the
numbering was not standard or consistent with the reported plan.
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Rather than providing headers for inclusion which replace any offered by
the system nolibc is provided in the form of a header which should be added
to the build via the compiler command line. In order to build with nolibc
we need to not include the standard C headers, especially not stdio.h where
the definitions of stdout, stdin and stderr will actively conflict with
nolibc.
Add an include guard which suppresses the inclusion of the standard headers
when building with nolibc, allowing us to build tests using the nolibc
headers. This allows us to avoid open coding of KTAP output for
selftests that need to use nolibc in order to test interfaces that are
controlled by libc.
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
vprintf() is equivalent to vfprintf() to stdout so implement it as a simple
wrapper for the existing vfprintf(), allowing us to build kselftest.h.
Suggested-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Willy Tarreau <w@1wt.eu>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Check both architectural rules and KVM's ABI for KVM_GET_SUPPORTED_CPUID
to ensure the supported xfeatures[1] don't violate any of them.
The architectural rules[2] and KVM's contract with userspace ensure for a
given feature, e.g. sse, avx, amx, etc... their associated xfeatures are
either all sets or none of them are set, and any dependencies are enabled
if needed.
[1] EDX:EAX of CPUID.(EAX=0DH,ECX=0)
[2] SDM vol 1, 13.3 ENABLING THE XSAVE FEATURE SET AND XSAVE-ENABLED
FEATURES
Cc: Mingwei Zhang <mizhang@google.com>
Signed-off-by: Aaron Lewis <aaronlewis@google.com>
[sean: expand comments, use a fancy X86_PROPERTY]
Reviewed-by: Aaron Lewis <aaronlewis@google.com>
Tested-by: Aaron Lewis <aaronlewis@google.com>
Link: https://lore.kernel.org/r/20230405004520.421768-7-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Take the XFeature mask in __vm_xsave_require_permission() instead of the
bit so that there's no need to define macros for both the bit and the
mask. Asserting that only a single bit is set and retrieving said bit
is easy enough via log2 helpers.
Opportunistically clean up the error message for the
ARCH_REQ_XCOMP_GUEST_PERM sanity check.
Reviewed-by: Aaron Lewis <aaronlewis@google.com>
Tested-by: Aaron Lewis <aaronlewis@google.com>
Link: https://lore.kernel.org/r/20230405004520.421768-5-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Add verifier log tests for BPF_BTF_LOAD command, which are very similar,
conceptually, to BPF_PROG_LOAD tests. These are two separate commands
dealing with verbose verifier log, so should be both tested separately.
Test that log_buf==NULL condition *does not* return -ENOSPC.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Lorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/bpf/20230406234205.323208-20-andrii@kernel.org
Add output-only log_true_size field to bpf_prog_load_opts to return
bpf_attr->log_true_size value back from bpf() syscall.
Note, that we have to drop const modifier from opts in bpf_prog_load().
This could potentially cause compilation error for some users. But
the usual practice is to define bpf_prog_load_ops
as a local variable next to bpf_prog_load() call and pass pointer to it,
so const vs non-const makes no difference and won't even come up in most
(if not all) cases.
There are no runtime and ABI backwards/forward compatibility issues at all.
If user provides old struct bpf_prog_load_opts, libbpf won't set new
fields. If old libbpf is provided new bpf_prog_load_opts, nothing will
happen either as old libbpf doesn't yet know about this new field.
Adding a new variant of bpf_prog_load() just for this seems like a big
and unnecessary overkill. As a corroborating evidence is the fact that
entire selftests/bpf code base required not adjustment whatsoever.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230406234205.323208-16-andrii@kernel.org
Add output-only log_true_size and btf_log_true_size field to
BPF_PROG_LOAD and BPF_BTF_LOAD commands, respectively. It will return
the size of log buffer necessary to fit in all the log contents at
specified log_level. This is very useful for BPF loader libraries like
libbpf to be able to size log buffer correctly, but could be used by
users directly, if necessary, as well.
This patch plumbs all this through the code, taking into account actual
bpf_attr size provided by user to determine if these new fields are
expected by users. And if they are, set them from kernel on return.
We refactory btf_parse() function to accommodate this, moving attr and
uattr handling inside it. The rest is very straightforward code, which
is split from the logging accounting changes in the previous patch to
make it simpler to review logic vs UAPI changes.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Lorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/bpf/20230406234205.323208-13-andrii@kernel.org
Add selftests validating BPF_LOG_FIXED behavior, which used to be the
only behavior, and now default rotating BPF verifier log, which returns
just up to last N bytes of full verifier log, instead of returning
-ENOSPC.
To stress test correctness of in-kernel verifier log logic, we force it
to truncate program's verifier log to all lengths from 1 all the way to
its full size (about 450 bytes today). This was a useful stress test
while developing the feature.
For both fixed and rotating log modes we expect -ENOSPC if log contents
doesn't fit in user-supplied log buffer.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Lorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/bpf/20230406234205.323208-7-andrii@kernel.org
Add --log-size to be able to customize log buffer sent to bpf() syscall
for BPF program verification logging.
Add --log-fixed to enforce BPF_LOG_FIXED behavior for BPF verifier log.
This is useful in unlikely event that beginning of truncated verifier
log is more important than the end of it (which with rotating verifier
log behavior is the default now).
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230406234205.323208-6-andrii@kernel.org
Currently, if user-supplied log buffer to collect BPF verifier log turns
out to be too small to contain full log, bpf() syscall returns -ENOSPC,
fails BPF program verification/load, and preserves first N-1 bytes of
the verifier log (where N is the size of user-supplied buffer).
This is problematic in a bunch of common scenarios, especially when
working with real-world BPF programs that tend to be pretty complex as
far as verification goes and require big log buffers. Typically, it's
when debugging tricky cases at log level 2 (verbose). Also, when BPF program
is successfully validated, log level 2 is the only way to actually see
verifier state progression and all the important details.
Even with log level 1, it's possible to get -ENOSPC even if the final
verifier log fits in log buffer, if there is a code path that's deep
enough to fill up entire log, even if normally it would be reset later
on (there is a logic to chop off successfully validated portions of BPF
verifier log).
In short, it's not always possible to pre-size log buffer. Also, what's
worse, in practice, the end of the log most often is way more important
than the beginning, but verifier stops emitting log as soon as initial
log buffer is filled up.
This patch switches BPF verifier log behavior to effectively behave as
rotating log. That is, if user-supplied log buffer turns out to be too
short, verifier will keep overwriting previously written log,
effectively treating user's log buffer as a ring buffer. -ENOSPC is
still going to be returned at the end, to notify user that log contents
was truncated, but the important last N bytes of the log would be
returned, which might be all that user really needs. This consistent
-ENOSPC behavior, regardless of rotating or fixed log behavior, allows
to prevent backwards compatibility breakage. The only user-visible
change is which portion of verifier log user ends up seeing *if buffer
is too small*. Given contents of verifier log itself is not an ABI,
there is no breakage due to this behavior change. Specialized tools that
rely on specific contents of verifier log in -ENOSPC scenario are
expected to be easily adapted to accommodate old and new behaviors.
Importantly, though, to preserve good user experience and not require
every user-space application to adopt to this new behavior, before
exiting to user-space verifier will rotate log (in place) to make it
start at the very beginning of user buffer as a continuous
zero-terminated string. The contents will be a chopped off N-1 last
bytes of full verifier log, of course.
Given beginning of log is sometimes important as well, we add
BPF_LOG_FIXED (which equals 8) flag to force old behavior, which allows
tools like veristat to request first part of verifier log, if necessary.
BPF_LOG_FIXED flag is also a simple and straightforward way to check if
BPF verifier supports rotating behavior.
On the implementation side, conceptually, it's all simple. We maintain
64-bit logical start and end positions. If we need to truncate the log,
start position will be adjusted accordingly to lag end position by
N bytes. We then use those logical positions to calculate their matching
actual positions in user buffer and handle wrap around the end of the
buffer properly. Finally, right before returning from bpf_check(), we
rotate user log buffer contents in-place as necessary, to make log
contents contiguous. See comments in relevant functions for details.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Lorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/bpf/20230406234205.323208-4-andrii@kernel.org
cli.py currently throws a pure KeyError if kernel doesn't support
a netlink family. Users who did not write ynl (hah) may waste
their time investigating what's wrong with the Python code.
Improve the error message:
Traceback (most recent call last):
File "/home/kicinski/devel/linux/tools/net/ynl/lib/ynl.py", line 362, in __init__
self.family = GenlFamily(self.yaml['name'])
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/kicinski/devel/linux/tools/net/ynl/lib/ynl.py", line 331, in __init__
self.genl_family = genl_family_name_to_id[family_name]
~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^
KeyError: 'netdev'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/home/kicinski/devel/linux/./tools/net/ynl/cli.py", line 52, in <module>
main()
File "/home/kicinski/devel/linux/./tools/net/ynl/cli.py", line 31, in main
ynl = YnlFamily(args.spec, args.schema)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/kicinski/devel/linux/tools/net/ynl/lib/ynl.py", line 364, in __init__
raise Exception(f"Family '{self.yaml['name']}' not supported by the kernel")
Exception: Family 'netdev' not supported by the kernel
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20230407145609.297525-1-kuba@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
If bperf (perf tools that use BPF skels) sets evsel->leader_skel or
evsel->follower_skel then it appears that evsel->bpf_skel is set and can
trigger the following use-after-free:
==13575==ERROR: AddressSanitizer: heap-use-after-free on address 0x60c000014080 at pc 0x55684b939880 bp 0x7ffdfcf30d70 sp 0x7ffdfcf30d68
READ of size 8 at 0x60c000014080 thread T0
#0 0x55684b93987f in sample_filter_bpf__destroy tools/perf/bpf_skel/sample_filter.skel.h:44:11
#1 0x55684b93987f in perf_bpf_filter__destroy tools/perf/util/bpf-filter.c:155:2
#2 0x55684b98f71e in evsel__exit tools/perf/util/evsel.c:1521:2
#3 0x55684b98a352 in evsel__delete tools/perf/util/evsel.c:1547:2
#4 0x55684b981918 in evlist__purge tools/perf/util/evlist.c:148:3
#5 0x55684b981918 in evlist__delete tools/perf/util/evlist.c:169:2
#6 0x55684b887d60 in cmd_stat tools/perf/builtin-stat.c:2598:2
..
0x60c000014080 is located 0 bytes inside of 128-byte region [0x60c000014080,0x60c000014100)
freed by thread T0 here:
#0 0x55684b780e86 in free compiler-rt/lib/asan/asan_malloc_linux.cpp:52:3
#1 0x55684b9462da in bperf_cgroup_bpf__destroy tools/perf/bpf_skel/bperf_cgroup.skel.h:61:2
#2 0x55684b9462da in bperf_cgrp__destroy tools/perf/util/bpf_counter_cgroup.c:282:2
#3 0x55684b944c75 in bpf_counter__destroy tools/perf/util/bpf_counter.c:819:2
#4 0x55684b98f716 in evsel__exit tools/perf/util/evsel.c:1520:2
#5 0x55684b98a352 in evsel__delete tools/perf/util/evsel.c:1547:2
#6 0x55684b981918 in evlist__purge tools/perf/util/evlist.c:148:3
#7 0x55684b981918 in evlist__delete tools/perf/util/evlist.c:169:2
#8 0x55684b887d60 in cmd_stat tools/perf/builtin-stat.c:2598:2
...
previously allocated by thread T0 here:
#0 0x55684b781338 in calloc compiler-rt/lib/asan/asan_malloc_linux.cpp:77:3
#1 0x55684b944e25 in bperf_cgroup_bpf__open_opts tools/perf/bpf_skel/bperf_cgroup.skel.h:73:35
#2 0x55684b944e25 in bperf_cgroup_bpf__open tools/perf/bpf_skel/bperf_cgroup.skel.h:97:9
#3 0x55684b944e25 in bperf_load_program tools/perf/util/bpf_counter_cgroup.c:55:9
#4 0x55684b944e25 in bperf_cgrp__load tools/perf/util/bpf_counter_cgroup.c:178:23
#5 0x55684b889289 in __run_perf_stat tools/perf/builtin-stat.c:713:7
#6 0x55684b889289 in run_perf_stat tools/perf/builtin-stat.c:949:8
#7 0x55684b888029 in cmd_stat tools/perf/builtin-stat.c:2537:12
Resolve by clearing 'evsel->bpf_skel' as part of bpf_counter__destroy().
Suggested-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: bpf@vger.kernel.org
Link: http://lore.kernel.org/lkml/20230411051718.267228-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Seen in "perf stat --bpf-counters --for-each-cgroup test" running in a
container:
libbpf: Failed to bump RLIMIT_MEMLOCK (err = -1), you might need to do it explicitly!
libbpf: Error in bpf_object__probe_loading():Operation not permitted(1). Couldn't load trivial BPF program. Make sure your kernel supports BPF (CONFIG_BPF_SYSCALL=y) and/or that RLIMIT_MEMLOCK is set to big enough value.
libbpf: failed to load object 'bperf_cgroup_bpf'
libbpf: failed to load BPF skeleton 'bperf_cgroup_bpf': -1
Failed to load cgroup skeleton
#0 0x55f28a650981 in list_empty tools/include/linux/list.h:189
#1 0x55f28a6593b4 in evsel__exit util/evsel.c:1518
#2 0x55f28a6596af in evsel__delete util/evsel.c:1544
#3 0x55f28a89d166 in bperf_cgrp__destroy util/bpf_counter_cgroup.c:283
#4 0x55f28a899e9a in bpf_counter__destroy util/bpf_counter.c:816
#5 0x55f28a659455 in evsel__exit util/evsel.c:1520
#6 0x55f28a6596af in evsel__delete util/evsel.c:1544
#7 0x55f28a640d4d in evlist__purge util/evlist.c:148
#8 0x55f28a640ea6 in evlist__delete util/evlist.c:169
#9 0x55f28a4efbf2 in cmd_stat tools/perf/builtin-stat.c:2598
#10 0x55f28a6050c2 in run_builtin tools/perf/perf.c:330
#11 0x55f28a605633 in handle_internal_command tools/perf/perf.c:384
#12 0x55f28a6059fb in run_argv tools/perf/perf.c:428
#13 0x55f28a6061d3 in main tools/perf/perf.c:562
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Florian Fischer <florian.fischer@muhq.space>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230410205659.3131608-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Interpretation of 'union perf_mem_data_src' by perf_mem__lvl_scnprintf()
is non-intuitive. For ex, it ignores 'mem_lvl' when 'mem_hops' is set
but considers it otherwise. It prints both 'mem_lvl_num' and 'mem_lvl'
when 'mem_hops' is not set.
Refactor this function such that it behaves more intuitively: Use new
API 'mem_lvl_num'|'mem_remote'|'mem_hops' if 'mem_lvl_num' contains
value other than PERF_MEM_LVLNUM_NA. Otherwise, fallback to old API
'mem_lvl'. Since new API has no way to indicate MISS, use it from old
api, otherwise don't club old and new APIs while parsing as well as
printing.
Before:
$ sudo ./perf mem report -F sample,mem --stdio
# Samples Memory access
# ............ ........................
#
250097 N/A
188907 L1 hit
4116 L2 hit
3496 Remote Cache (1 hop) hit
3271 Remote Cache (2 hops) hit
873 L3 hit
598 Local RAM hit
438 Remote RAM (1 hop) hit
1 Uncached hit
After:
$ sudo ./perf mem report -F sample,mem --stdio
# Samples Memory access
# ............ .......................................
#
255517 N/A
189989 L1 hit
4541 L2 hit
3363 Remote core, same node Any cache hit
3336 Remote node, same socket Any cache hit
1275 L3 hit
743 RAM hit
545 Remote node, same socket RAM hit
4 Uncached hit
Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ananth Narayan <ananth.narayan@amd.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Santosh Shukla <santosh.shukla@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20230407112459.548-5-ravi.bangoria@amd.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull virtio fixes from Michael Tsirkin:
"Some last minute fixes - most of them for regressions"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
vdpa_sim_net: complete the initialization before register the device
vdpa/mlx5: Add and remove debugfs in setup/teardown driver
tools/virtio: fix typo in README instructions
vhost-scsi: Fix crash during LUN unmapping
vhost-scsi: Fix vhost_scsi struct use after free
virtio-blk: fix ZBD probe in kernels without ZBD support
virtio-blk: fix to match virtio spec
get_llc_perf() function comment refers to cpu_no parameter that does
not exist.
Correct get_llc_perf() the comment to document llc_perf_miss instead.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
