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These tests have been developed in the hid-tools[0] tree for a while.
Now that we have a proper selftests/hid kernel entry and that the tests
are more reliable, it is time to directly include those in the kernel
tree.
[0] https://gitlab.freedesktop.org/libevdev/hid-tools
Cc: Jason Gerecke <[email protected]>
Signed-off-by: Benjamin Tissoires <[email protected]>
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These tests have been developed in the hid-tools[0] tree for a while.
Now that we have a proper selftests/hid kernel entry and that the tests
are more reliable, it is time to directly include those in the kernel
tree.
There are a lot of multitouch tests, and the default timeout of 45 seconds
is not big enough. Bump it to 200 seconds.
[0] https://gitlab.freedesktop.org/libevdev/hid-tools
Cc: Peter Hutterer <[email protected]>
Cc: Kai-Heng Feng <[email protected]>
Cc: Roderick Colenbrander <[email protected]>
Cc: наб <[email protected]>
Cc: Blaž Hrastnik <[email protected]>
Signed-off-by: Ahelenia Ziemiańska <[email protected]>
Signed-off-by: Peter Hutterer <[email protected]>
Signed-off-by: Roderick Colenbrander <[email protected]>
Signed-off-by: Benjamin Tissoires <[email protected]>
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These tests have been developed in the hid-tools[0] tree for a while.
Now that we have a proper selftests/hid kernel entry and that the tests
are more reliable, it is time to directly include those in the kernel
tree.
[0] https://gitlab.freedesktop.org/libevdev/hid-tools
Cc: Peter Hutterer <[email protected]>
Cc: Roderick Colenbrander <[email protected]>
Signed-off-by: Peter Hutterer <[email protected]>
Signed-off-by: Roderick Colenbrander <[email protected]>
Signed-off-by: Benjamin Tissoires <[email protected]>
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These tests have been developed in the hid-tools[0] tree for a while.
Now that we have a proper selftests/hid kernel entry and that the tests
are more reliable, it is time to directly include those in the kernel
tree.
[0] https://gitlab.freedesktop.org/libevdev/hid-tools
Cc: Nicolas Saenz Julienne <[email protected]>
Cc: Peter Hutterer <[email protected]>
Cc: Roderick Colenbrander <[email protected]>
Signed-off-by: Peter Hutterer <[email protected]>
Signed-off-by: Roderick Colenbrander <[email protected]>
Signed-off-by: Benjamin Tissoires <[email protected]>
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These tests have been developed in the hid-tools[0] tree for a while.
Now that we have a proper selftests/hid kernel entry and that the tests
are more reliable, it is time to directly include those in the kernel
tree.
[0] https://gitlab.freedesktop.org/libevdev/hid-tools
Cc: Candle Sun <[email protected]>
Cc: Jose Torreguitar <[email protected]>
Cc: Peter Hutterer <[email protected]>
Cc: Roderick Colenbrander <[email protected]>
Cc: Silvan Jegen <[email protected]>
Signed-off-by: Silvan Jegen <[email protected]>
Signed-off-by: Peter Hutterer <[email protected]>
Signed-off-by: Roderick Colenbrander <[email protected]>
Signed-off-by: Benjamin Tissoires <[email protected]>
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These tests have been developed in the hid-tools[0] tree for a while.
Now that we have a proper selftests/hid kernel entry and that the tests
are more reliable, it is time to directly include those in the kernel
tree.
I haven't imported all of hid-tools, the python module, but only the
tests related to the kernel. We can rely on pip to fetch the latest
hid-tools release, and then run the tests directly from the tree.
This should now be easier to request tests when something is not behaving
properly in the HID subsystem.
[0] https://gitlab.freedesktop.org/libevdev/hid-tools
Cc: Peter Hutterer <[email protected]>
Signed-off-by: Peter Hutterer <[email protected]>
Signed-off-by: Benjamin Tissoires <[email protected]>
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Having a default binary is simple enough, but this also means that
we need to keep the targets in sync as we are adding them in the Makefile.
So instead of doing that manual work, make vmtest.sh generic enough to
actually be capable of running 'make -C tools/testing/selftests/hid'.
The new image we use has make installed, which the base fedora image
doesn't.
Signed-off-by: Benjamin Tissoires <[email protected]>
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In __cmd_top(), perf_set_multithreaded() is used to enable
pthread_rwlock, thus down_read() and down_write () are not nops,
handling concurrency problems
Then 'perf top' uses perf_set_singlethreaded(), switching to the single
threaded phase, assuming that no thread concurrency will happen later.
However, a use after free problem could occur in the single threaded
phase, the concurrent procedure is this:
display_thread process_thread
-------------- --------------
thread__comm_len
-> thread__comm_str
-> __thread__comm_str(thread)
thread__delete
-> comm__free
-> comm_str__put
-> zfree(&cs->str)
-> thread->comm_len = strlen(comm);
Since in single thread phase, perf_singlethreaded is true, down_read()
and down_write() do nothing to avoid concurrency problems.
This patch moves the perf_set_singlethreaded() call to the function tail
to expand the multithreaded phase range, making display_thread() and
process_thread() concurrency safe.
Reviewed-by: Yunfeng Ye <[email protected]>
Signed-off-by: Hangliang Lai <[email protected]>
Co-developed-by: Wenyu Liu <[email protected]>
Acked-by: Namhyung Kim <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Feilong Lin <[email protected]>
Cc: Hewenliang <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Mark Rutland <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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After commit 1f265d2aea0dff1f ("selftests/bpf: Remove not used headers"),
tools/arch/s390/include/uapi/asm/ptrace.h has been removed, so remove
it in check-headers.sh too, otherwise we can see the following build
warning:
diff: tools/arch/s390/include/uapi/asm/ptrace.h: No such file or directory
Fixes: 1f265d2aea0dff1f ("selftests/bpf: Remove not used headers")
Reported-by: kernel test robot <[email protected]>
Signed-off-by: Tiezhu Yang <[email protected]>
Acked-by: Daniel Borkmann <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Andrii Nakryiko <[email protected]>
Cc: Tiezhu Yang <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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its contents
An audit showed just this one problem with zfree(), fix it.
Fixes: 9fbc61f832ebf432 ("perf pmu: Add support for PMU capabilities")
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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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.
This file already used zfree() in other places, so this just plugs some
leftovers.
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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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 <[email protected]>
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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 <[email protected]>
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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 <[email protected]>
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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 <[email protected]>
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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 <[email protected]>
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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.
Also include the missing linux/zalloc.h header directive.
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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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.
Also remove one NULL test before free(), as it accepts a NULL arg and we
get one line shaved not doing it explicitely.
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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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.
Also remove one NULL test before free(), as it accepts a NULL arg and we
get one line shaved not doing it explicitely.
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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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.
Also remove one NULL test before free(), as it accepts a NULL arg and we
get one line shaved not doing it explicitely.
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
|
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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 <[email protected]>
|
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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 <[email protected]>
|
|
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 <[email protected]>
|
|
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 <[email protected]>
|
|
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 <[email protected]>
|
|
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 <[email protected]>
|
|
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 <[email protected]>
|
|
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 <[email protected]>
|
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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 <[email protected]>
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Update from v1.19 to v1.20 affecting the uncore
UNC_CHA_CORE_SNP.REMOTE_GTONE event's umask.
Signed-off-by: Ian Rogers <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Xing Zhengjun <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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Update from v1.19 to v1.20 affecting the performance/goldencove
events. Adds cmask=1 for ARITH.IDIV_ACTIVE, and updates event
descriptions.
Signed-off-by: Ian Rogers <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Xing Zhengjun <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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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 <[email protected]>
Signed-off-by: Shuah Khan <[email protected]>
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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 <[email protected]>
Signed-off-by: Shuah Khan <[email protected]>
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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 <[email protected]>
Signed-off-by: Mark Brown <[email protected]>
Acked-by: Willy Tarreau <[email protected]>
Acked-by: Paul E. McKenney <[email protected]>
Acked-by: Shuah Khan <[email protected]>
Signed-off-by: Shuah Khan <[email protected]>
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Adding verifier test for accessing u32 pointer argument in
tracing programs.
The test program loads 1nd argument of bpf_fentry_test9 function
which is u32 pointer and checks that verifier allows that.
Co-developed-by: Chengming Zhou <[email protected]>
Signed-off-by: Chengming Zhou <[email protected]>
Signed-off-by: Feng Zhou <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
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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 <[email protected]>
Signed-off-by: Aaron Lewis <[email protected]>
[sean: expand comments, use a fancy X86_PROPERTY]
Reviewed-by: Aaron Lewis <[email protected]>
Tested-by: Aaron Lewis <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>
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Add all known XFEATURE masks to processor.h to make them more broadly
available in KVM selftests. Relocate and clean up the exiting AMX (XTILE)
defines in processor.h, e.g. drop the intermediate define and use BIT_ULL.
Signed-off-by: Aaron Lewis <[email protected]>
Reviewed-by: Aaron Lewis <[email protected]>
Tested-by: Aaron Lewis <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>
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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 <[email protected]>
Tested-by: Aaron Lewis <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>
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The instructions XGETBV and XSETBV are useful to other tests. Move
them to processor.h to make them more broadly available.
No functional change intended.
Reviewed-by: Jim Mattson <[email protected]>
Signed-off-by: Aaron Lewis <[email protected]>
Reviewed-by: Mingwei Zhang <[email protected]>
[sean: reword shortlog]
Reviewed-by: Aaron Lewis <[email protected]>
Tested-by: Aaron Lewis <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>
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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 <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Acked-by: Lorenz Bauer <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
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Add few extra test conditions to validate that it's ok to pass
log_buf==NULL and log_size==0 to BPF_PROG_LOAD command with the intent
to get log_true_size without providing a buffer.
Test that log_buf==NULL condition *does not* return -ENOSPC.
Signed-off-by: Andrii Nakryiko <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Acked-by: Lorenz Bauer <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
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Add additional test cases validating that log_true_size is consistent
between fixed and rotating log modes, and that log_true_size can be
used *exactly* without causing -ENOSPC, while using just 1 byte shorter
log buffer would cause -ENOSPC.
Signed-off-by: Andrii Nakryiko <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Acked-by: Lorenz Bauer <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
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Similar to what we did for bpf_prog_load() in previous patch, wire
returning of log_true_size value from kernel back to the user through
OPTS out field.
Signed-off-by: Andrii Nakryiko <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
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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 <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
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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 <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Acked-by: Lorenz Bauer <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
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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 <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Acked-by: Lorenz Bauer <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
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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 <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
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This basically prevents any forward compatibility. And we either way
just return -EINVAL, which would otherwise be returned from bpf()
syscall anyways.
Similarly, drop enforcement of non-NULL log_buf when log_level > 0. This
won't be true anymore soon.
Signed-off-by: Andrii Nakryiko <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Acked-by: Lorenz Bauer <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
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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 <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Reviewed-by: Lorenz Bauer <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
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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 <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
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