Make libbpf adjust RINGBUF map size (rounding it up to closest power-of-2
of page_size) more eagerly: during open phase when initializing the map
and on explicit calls to bpf_map__set_max_entries().
Such approach allows user to check actual size of BPF ringbuf even
before it's created in the kernel, but also it prevents various edge
case scenarios where BPF ringbuf size can get out of sync with what it
would be in kernel. One of them (reported in [0]) is during an attempt
to pin/reuse BPF ringbuf.
Move adjust_ringbuf_sz() helper closer to its first actual use. The
implementation of the helper is unchanged.
Also make detection of whether bpf_object is already loaded more robust
by checking obj->loaded explicitly, given that map->fd can be < 0 even
if bpf_object is already loaded due to ability to disable map creation
with bpf_map__set_autocreate(map, false).
[0] Closes: https://github.com/libbpf/libbpf/pull/530
Fixes: 0087a681fa ("libbpf: Automatically fix up BPF_MAP_TYPE_RINGBUF size, if necessary")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20220715230952.2219271-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add SEC("ksyscall")/SEC("ksyscall/<syscall_name>") and corresponding
kretsyscall variants (for return kprobes) to allow users to kprobe
syscall functions in kernel. These special sections allow to ignore
complexities and differences between kernel versions and host
architectures when it comes to syscall wrapper and corresponding
__<arch>_sys_<syscall> vs __se_sys_<syscall> differences, depending on
whether host kernel has CONFIG_ARCH_HAS_SYSCALL_WRAPPER (though libbpf
itself doesn't rely on /proc/config.gz for detecting this, see
BPF_KSYSCALL patch for how it's done internally).
Combined with the use of BPF_KSYSCALL() macro, this allows to just
specify intended syscall name and expected input arguments and leave
dealing with all the variations to libbpf.
In addition to SEC("ksyscall+") and SEC("kretsyscall+") add
bpf_program__attach_ksyscall() API which allows to specify syscall name
at runtime and provide associated BPF cookie value.
At the moment SEC("ksyscall") and bpf_program__attach_ksyscall() do not
handle all the calling convention quirks for mmap(), clone() and compat
syscalls. It also only attaches to "native" syscall interfaces. If host
system supports compat syscalls or defines 32-bit syscalls in 64-bit
kernel, such syscall interfaces won't be attached to by libbpf.
These limitations may or may not change in the future. Therefore it is
recommended to use SEC("kprobe") for these syscalls or if working with
compat and 32-bit interfaces is required.
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220714070755.3235561-5-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Improve BPF_KPROBE_SYSCALL (and rename it to shorter BPF_KSYSCALL to
match libbpf's SEC("ksyscall") section name, added in next patch) to use
__kconfig variable to determine how to properly fetch syscall arguments.
Instead of relying on hard-coded knowledge of whether kernel's
architecture uses syscall wrapper or not (which only reflects the latest
kernel versions, but is not necessarily true for older kernels and won't
necessarily hold for later kernel versions on some particular host
architecture), determine this at runtime by attempting to create
perf_event (with fallback to kprobe event creation through tracefs on
legacy kernels, just like kprobe attachment code is doing) for kernel
function that would correspond to bpf() syscall on a system that has
CONFIG_ARCH_HAS_SYSCALL_WRAPPER set (e.g., for x86-64 it would try
'__x64_sys_bpf').
If host kernel uses syscall wrapper, syscall kernel function's first
argument is a pointer to struct pt_regs that then contains syscall
arguments. In such case we need to use bpf_probe_read_kernel() to fetch
actual arguments (which we do through BPF_CORE_READ() macro) from inner
pt_regs.
But if the kernel doesn't use syscall wrapper approach, input
arguments can be read from struct pt_regs directly with no probe reading.
All this feature detection is done without requiring /proc/config.gz
existence and parsing, and BPF-side helper code uses newly added
LINUX_HAS_SYSCALL_WRAPPER virtual __kconfig extern to keep in sync with
user-side feature detection of libbpf.
BPF_KSYSCALL() macro can be used both with SEC("kprobe") programs that
define syscall function explicitly (e.g., SEC("kprobe/__x64_sys_bpf"))
and SEC("ksyscall") program added in the next patch (which are the same
kprobe program with added benefit of libbpf determining correct kernel
function name automatically).
Kretprobe and kretsyscall (added in next patch) programs don't need
BPF_KSYSCALL as they don't provide access to input arguments. Normal
BPF_KRETPROBE is completely sufficient and is recommended.
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220714070755.3235561-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Libbpf supports single virtual __kconfig extern currently: LINUX_KERNEL_VERSION.
LINUX_KERNEL_VERSION isn't coming from /proc/kconfig.gz and is intead
customly filled out by libbpf.
This patch generalizes this approach to support more such virtual
__kconfig externs. One such extern added in this patch is
LINUX_HAS_BPF_COOKIE which is used for BPF-side USDT supporting code in
usdt.bpf.h instead of using CO-RE-based enum detection approach for
detecting bpf_get_attach_cookie() BPF helper. This allows to remove
otherwise not needed CO-RE dependency and keeps user-space and BPF-side
parts of libbpf's USDT support strictly in sync in terms of their
feature detection.
We'll use similar approach for syscall wrapper detection for
BPF_KSYSCALL() BPF-side macro in follow up patch.
Generally, currently libbpf reserves CONFIG_ prefix for Kconfig values
and LINUX_ for virtual libbpf-backed externs. In the future we might
extend the set of prefixes that are supported. This can be done without
any breaking changes, as currently any __kconfig extern with
unrecognized name is rejected.
For LINUX_xxx externs we support the normal "weak rule": if libbpf
doesn't recognize given LINUX_xxx extern but such extern is marked as
__weak, it is not rejected and defaults to zero. This follows
CONFIG_xxx handling logic and will allow BPF applications to
opportunistically use newer libbpf virtual externs without breaking on
older libbpf versions unnecessarily.
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220714070755.3235561-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Silence this perf build warning:
Warning: Kernel ABI header at 'tools/include/uapi/linux/kvm.h' differs from latest version at 'include/uapi/linux/kvm.h'
diff -u tools/include/uapi/linux/kvm.h include/uapi/linux/kvm.h
Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In rseq_test, there are two threads, which are vCPU thread and migration
worker separately. Unfortunately, the test has the wrong PID passed to
sched_setaffinity() in the migration worker. It forces migration on the
migration worker because zeroed PID represents the calling thread, which
is the migration worker itself. It means the vCPU thread is never enforced
to migration and it can migrate at any time, which eventually leads to
failure as the following logs show.
host# uname -r
5.19.0-rc6-gavin+
host# # cat /proc/cpuinfo | grep processor | tail -n 1
processor : 223
host# pwd
/home/gavin/sandbox/linux.main/tools/testing/selftests/kvm
host# for i in `seq 1 100`; do \
echo "--------> $i"; ./rseq_test; done
--------> 1
--------> 2
--------> 3
--------> 4
--------> 5
--------> 6
==== Test Assertion Failure ====
rseq_test.c:265: rseq_cpu == cpu
pid=3925 tid=3925 errno=4 - Interrupted system call
1 0x0000000000401963: main at rseq_test.c:265 (discriminator 2)
2 0x0000ffffb044affb: ?? ??:0
3 0x0000ffffb044b0c7: ?? ??:0
4 0x0000000000401a6f: _start at ??:?
rseq CPU = 4, sched CPU = 27
Fix the issue by passing correct parameter, TID of the vCPU thread, to
sched_setaffinity() in the migration worker.
Fixes: 61e52f1630 ("KVM: selftests: Add a test for KVM_RUN+rseq to detect task migration bugs")
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Message-Id: <20220719020830.3479482-1-gshan@redhat.com>
Reviewed-by: Andrew Jones <andrew.jones@linux.dev>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This new option displays all of the information needed to do external
BuildID-based symbolization of kernel stack traces, such as those collected
by bpf_get_stackid().
For each kernel module plus the main kernel, it displays the BuildID,
the start and end virtual addresses of that module's text range (rounded
out to page boundaries), and the pathname of the module.
When run as a non-privileged user, the actual addresses of the modules'
text ranges are not available, so the tools displays "0, <text length>" for
kernel modules and "0, 0xffffffffffffffff" for the kernel itself.
Sample output:
root# perf buildid-list -m
cf6df852fd4da122d616153353cc8f560fd12fe0 ffffffffa5400000 ffffffffa6001e27 [kernel.kallsyms]
1aa7209aa2acb067d66ed6cf7676d65066384d61 ffffffffc0087000 ffffffffc008b000 /lib/modules/5.15.15-1rodete2-amd64/kernel/crypto/sha512_generic.ko
3857815b5bf0183697b68f8fe0ea06121644041e ffffffffc008c000 ffffffffc0098000 /lib/modules/5.15.15-1rodete2-amd64/kernel/arch/x86/crypto/sha512-ssse3.ko
4081fde0bca2bc097cb3e9d1efcb836047d485f1 ffffffffc0099000 ffffffffc009f000 /lib/modules/5.15.15-1rodete2-amd64/kernel/drivers/acpi/button.ko
1ef81ba4890552ea6b0314f9635fc43fc8cef568 ffffffffc00a4000 ffffffffc00aa000 /lib/modules/5.15.15-1rodete2-amd64/kernel/crypto/cryptd.ko
cc5c985506cb240d7d082b55ed260cbb851f983e ffffffffc00af000 ffffffffc00b6000 /lib/modules/5.15.15-1rodete2-amd64/kernel/drivers/i2c/busses/i2c-piix4.ko
[...]
Committer notes:
u64 formatter should be PRIx64 for printing as hex numbers, fix this:
28 5.28 debian:experimental-x-mips : FAIL gcc version 11.2.0 (Debian 11.2.0-18)
builtin-buildid-list.c: In function 'buildid__map_cb':
builtin-buildid-list.c:32:24: error: format '%lx' expects argument of type 'long unsigned int', but argument 3 has type 'u64' {aka 'long long unsigned int'} [-Werror=format=]
32 | printf("%s %16lx %16lx", bid_buf, map->start, map->end);
| ~~~~^ ~~~~~~~~~~
| | |
| long unsigned int u64 {aka long long unsigned int}
| %16llx
builtin-buildid-list.c:32:30: error: format '%lx' expects argument of type 'long unsigned int', but argument 4 has type 'u64' {aka 'long long unsigned int'} [-Werror=format=]
32 | printf("%s %16lx %16lx", bid_buf, map->start, map->end);
| ~~~~^ ~~~~~~~~
| | |
| long unsigned int u64 {aka long long unsigned int}
| %16llx
cc1: all warnings being treated as errors
Signed-off-by: Blake Jones <blakejones@google.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220629213632.3899212-1-blakejones@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To update the perf/core codebase.
Fix conflict by moving arch__post_evsel_config(evsel, attr) to the end
of evsel__config(), after what was added in:
49c692b7df ("perf offcpu: Accept allowed sample types only")
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When RDRAND was introduced, there was much discussion on whether it
should be trusted and how the kernel should handle that. Initially, two
mechanisms cropped up, CONFIG_ARCH_RANDOM, a compile time switch, and
"nordrand", a boot-time switch.
Later the thinking evolved. With a properly designed RNG, using RDRAND
values alone won't harm anything, even if the outputs are malicious.
Rather, the issue is whether those values are being *trusted* to be good
or not. And so a new set of options were introduced as the real
ones that people use -- CONFIG_RANDOM_TRUST_CPU and "random.trust_cpu".
With these options, RDRAND is used, but it's not always credited. So in
the worst case, it does nothing, and in the best case, maybe it helps.
Along the way, CONFIG_ARCH_RANDOM's meaning got sort of pulled into the
center and became something certain platforms force-select.
The old options don't really help with much, and it's a bit odd to have
special handling for these instructions when the kernel can deal fine
with the existence or untrusted existence or broken existence or
non-existence of that CPU capability.
Simplify the situation by removing CONFIG_ARCH_RANDOM and using the
ordinary asm-generic fallback pattern instead, keeping the two options
that are actually used. For now it leaves "nordrand" for now, as the
removal of that will take a different route.
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Booting with vsyscall=xonly results in the following vsyscall VMA:
ffffffffff600000-ffffffffff601000 --xp ... [vsyscall]
Test does read from fixed vsyscall address to determine if kernel
supports vsyscall page but it doesn't work because, well, vsyscall
page is execute only.
Fix test by trying to execute from the first byte of the page which
contains gettimeofday() stub. This should work because vsyscall
entry points have stable addresses by design.
Alexey, avoiding parsing .config, /proc/config.gz and
/proc/cmdline at all costs.
Link: https://lkml.kernel.org/r/Ys2KgeiEMboU8Ytu@localhost.localdomain
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: <dylanbhatch@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Test cases such as migrate_fault and migrate_multiple, were modified to
explicit migrate from device to sys memory without the need of page
faults, when using device coherent type.
Snapshot test case updated to read memory device type first and based on
that, get the proper returned results migrate_ping_pong test case added to
test explicit migration from device to sys memory for both private and
coherent zone types.
Helpers to migrate from device to sys memory and vicerversa were also
added.
Link: https://lkml.kernel.org/r/20220715150521.18165-12-alex.sierra@amd.com
Signed-off-by: Alex Sierra <alex.sierra@amd.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
On powerpc, 'perf trace' is crashing with a SIGSEGV when trying to
process a perf.data file created with 'perf trace record -p':
#0 0x00000001225b8988 in syscall_arg__scnprintf_augmented_string <snip> at builtin-trace.c:1492
#1 syscall_arg__scnprintf_filename <snip> at builtin-trace.c:1492
#2 syscall_arg__scnprintf_filename <snip> at builtin-trace.c:1486
#3 0x00000001225bdd9c in syscall_arg_fmt__scnprintf_val <snip> at builtin-trace.c:1973
#4 syscall__scnprintf_args <snip> at builtin-trace.c:2041
#5 0x00000001225bff04 in trace__sys_enter <snip> at builtin-trace.c:2319
That points to the below code in tools/perf/builtin-trace.c:
/*
* If this is raw_syscalls.sys_enter, then it always comes with the 6 possible
* arguments, even if the syscall being handled, say "openat", uses only 4 arguments
* this breaks syscall__augmented_args() check for augmented args, as we calculate
* syscall->args_size using each syscalls:sys_enter_NAME tracefs format file,
* so when handling, say the openat syscall, we end up getting 6 args for the
* raw_syscalls:sys_enter event, when we expected just 4, we end up mistakenly
* thinking that the extra 2 u64 args are the augmented filename, so just check
* here and avoid using augmented syscalls when the evsel is the raw_syscalls one.
*/
if (evsel != trace->syscalls.events.sys_enter)
augmented_args = syscall__augmented_args(sc, sample, &augmented_args_size, trace->raw_augmented_syscalls_args_size);
As the comment points out, we should not be trying to augment the args
for raw_syscalls. However, when processing a perf.data file, we are not
initializing those properly. Fix the same.
Reported-by: Claudio Carvalho <cclaudio@linux.ibm.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/20220707090900.572584-1-naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To pick up the changes from these csets:
4ad3278df6 ("x86/speculation: Disable RRSBA behavior")
d7caac991f ("x86/cpu/amd: Add Spectral Chicken")
That cause no changes to tooling:
$ tools/perf/trace/beauty/tracepoints/x86_msr.sh > before
$ cp arch/x86/include/asm/msr-index.h tools/arch/x86/include/asm/msr-index.h
$ tools/perf/trace/beauty/tracepoints/x86_msr.sh > after
$ diff -u before after
$
Just silences this perf build warning:
Warning: Kernel ABI header at 'tools/arch/x86/include/asm/msr-index.h' differs from latest version at 'arch/x86/include/asm/msr-index.h'
diff -u tools/arch/x86/include/asm/msr-index.h arch/x86/include/asm/msr-index.h
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/lkml/YtQTm9wsB3hxQWvy@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To pick the changes from:
f43b9876e8 ("x86/retbleed: Add fine grained Kconfig knobs")
a149180fbc ("x86: Add magic AMD return-thunk")
15e67227c4 ("x86: Undo return-thunk damage")
369ae6ffc4 ("x86/retpoline: Cleanup some #ifdefery")
4ad3278df6 x86/speculation: Disable RRSBA behavior
26aae8ccbc x86/cpu/amd: Enumerate BTC_NO
9756bba284 x86/speculation: Fill RSB on vmexit for IBRS
3ebc170068 x86/bugs: Add retbleed=ibpb
2dbb887e87 x86/entry: Add kernel IBRS implementation
6b80b59b35 x86/bugs: Report AMD retbleed vulnerability
a149180fbc x86: Add magic AMD return-thunk
15e67227c4 x86: Undo return-thunk damage
a883d624ae x86/cpufeatures: Move RETPOLINE flags to word 11
5180218615 x86/speculation/mmio: Enumerate Processor MMIO Stale Data bug
This only causes these perf files to be rebuilt:
CC /tmp/build/perf/bench/mem-memcpy-x86-64-asm.o
CC /tmp/build/perf/bench/mem-memset-x86-64-asm.o
And addresses this perf build warning:
Warning: Kernel ABI header at 'tools/arch/x86/include/asm/cpufeatures.h' differs from latest version at 'arch/x86/include/asm/cpufeatures.h'
diff -u tools/arch/x86/include/asm/cpufeatures.h arch/x86/include/asm/cpufeatures.h
Warning: Kernel ABI header at 'tools/arch/x86/include/asm/disabled-features.h' differs from latest version at 'arch/x86/include/asm/disabled-features.h'
diff -u tools/arch/x86/include/asm/disabled-features.h arch/x86/include/asm/disabled-features.h
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org
Link: https://lore.kernel.org/lkml/YtQM40VmiLTkPND2@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To pick the changes in:
1b870fa557 ("kvm: stats: tell userspace which values are boolean")
That just rebuilds perf, as these patches don't add any new KVM ioctl to
be harvested for the the 'perf trace' ioctl syscall argument
beautifiers.
This is also by now used by tools/testing/selftests/kvm/, a simple test
build succeeded.
This silences this perf build warning:
Warning: Kernel ABI header at 'tools/include/uapi/linux/kvm.h' differs from latest version at 'include/uapi/linux/kvm.h'
diff -u tools/include/uapi/linux/kvm.h include/uapi/linux/kvm.h
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Link: http://lore.kernel.org/lkml/YtQLDvQrBhJNl3n5@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
ipv4 arp_accept has a new option '2' to create new neighbor entries
only if the src ip is in the same subnet as an address configured on
the interface that received the garp message. This selftest tests all
options in arp_accept.
ipv6 has a sysctl endpoint, accept_untracked_na, that defines the
behavior for accepting untracked neighbor advertisements. A new option
similar to that of arp_accept for learning only from the same subnet is
added to accept_untracked_na. This selftest tests this new feature.
Signed-off-by: Jaehee Park <jhpark1013@gmail.com>
Suggested-by: Roopa Prabhu <roopa@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add support for writing a custom event reader, by exposing the ring
buffer.
With the new API perf_buffer__buffer() you will get access to the
raw mmaped()'ed per-cpu underlying memory of the ring buffer.
This region contains both the perf buffer data and header
(struct perf_event_mmap_page), which manages the ring buffer
state (head/tail positions, when accessing the head/tail position
it's important to take into consideration SMP).
With this type of low level access one can implement different types of
consumers here are few simple examples where this API helps with:
1. perf_event_read_simple is allocating using malloc, perhaps you want
to handle the wrap-around in some other way.
2. Since perf buf is per-cpu then the order of the events is not
guarnteed, for example:
Given 3 events where each event has a timestamp t0 < t1 < t2,
and the events are spread on more than 1 CPU, then we can end
up with the following state in the ring buf:
CPU[0] => [t0, t2]
CPU[1] => [t1]
When you consume the events from CPU[0], you could know there is
a t1 missing, (assuming there are no drops, and your event data
contains a sequential index).
So now one can simply do the following, for CPU[0], you can store
the address of t0 and t2 in an array (without moving the tail, so
there data is not perished) then move on the CPU[1] and set the
address of t1 in the same array.
So you end up with something like:
void **arr[] = [&t0, &t1, &t2], now you can consume it orderely
and move the tails as you process in order.
3. Assuming there are multiple CPUs and we want to start draining the
messages from them, then we can "pick" with which one to start with
according to the remaining free space in the ring buffer.
Signed-off-by: Jon Doron <jond@wiz.io>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220715181122.149224-1-arilou@gmail.com
Add some notes on how to run the test, update the policy file paths to
reflect recent upstream changes, prepare test for adding GID testing.
Signed-off-by: Micah Morton <mortonm@chromium.org>
Not sure how this bug got in here but its been there since the original
merge. I think I tested the code on a system that wouldn't let me
clone() with CLONE_NEWUSER flag set so had to comment out these
test_userns invocations.
Trying to map UID 0 inside the userns to UID 0 outside will never work,
even with CAP_SETUID. The code is supposed to test whether we can map
UID 0 in the userns to the UID of the parent process (the one with
CAP_SETUID that is writing the /proc/[pid]/uid_map file).
Signed-off-by: Micah Morton <mortonm@chromium.org>
bootgraph:
- fix parsing of /proc/version to be much more flexible
- check kernel version to disallow ftrace on anything older than 4.10
sleepgraph:
- include fix to bugzilla 212761 in case it regresses
- fix for -proc bug: https://github.com/intel/pm-graph/pull/20
- add -debugtiming arg to get timestamps on prints
- allow use of the netfix tool hosted in the github repo
- read s0ix data from pmc_core for better debug
- include more system data in the output log
- Do a better job testing input files useability
- flag more error data from dmesg in the timeline
- pre-parse the trace log to fix any ordering issues
- add new parser to process dmesg only timelines
- remove superflous sleep(5) in multitest mode
config/custom-timeline-functions.cfg:
- change some names to keep up to date
README:
- new version, small wording changes
Signed-off-by: Todd Brandt <todd.e.brandt@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
bitmap_weight() doesn't return negative values, so change it's type
to unsigned long. It may help compiler to generate better code and
catch bugs.
Signed-off-by: Yury Norov <yury.norov@gmail.com>
The current vgic_init test wrongly assumes that the host cannot
multiple versions of the GIC architecture, while v2 emulation
on v3 has almost always been supported (it was supported before
the standalone v3 emulation).
Tweak the test to support multiple GIC incarnations.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Fixes: 3f4db37e20 ("KVM: arm64: selftests: Make vgic_init gic version agnostic")
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Link: https://lore.kernel.org/r/20220714154108.3531213-1-maz@kernel.org
Alexei reported crash by running test_progs -j on system
with 32 cpus.
It turned out the kprobe_multi bench test that attaches all
ftrace-able functions will race with bpf_dispatcher_update,
that calls bpf_arch_text_poke on bpf_dispatcher_xdp_func,
which is ftrace-able function.
Ftrace is not aware of this update so this will cause
ftrace_bug with:
WARNING: CPU: 6 PID: 1985 at
arch/x86/kernel/ftrace.c:94 ftrace_verify_code+0x27/0x50
...
ftrace_replace_code+0xa3/0x170
ftrace_modify_all_code+0xbd/0x150
ftrace_startup_enable+0x3f/0x50
ftrace_startup+0x98/0xf0
register_ftrace_function+0x20/0x60
register_fprobe_ips+0xbb/0xd0
bpf_kprobe_multi_link_attach+0x179/0x430
__sys_bpf+0x18a1/0x2440
...
------------[ ftrace bug ]------------
ftrace failed to modify
[<ffffffff818d9380>] bpf_dispatcher_xdp_func+0x0/0x10
actual: ffffffe9:7b:ffffff9c:77:1e
Setting ftrace call site to call ftrace function
It looks like we need some way to hide some functions
from ftrace, but meanwhile we workaround this by skipping
bpf_dispatcher_xdp_func from kprobe_multi bench test.
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220714082316.479181-1-jolsa@kernel.org
Some bitmap functions return boolean results in int variables. Fix it
by changing return types to bool.
Signed-off-by: Yury Norov <yury.norov@gmail.com>
The khdr make target has been removed, so drop it from the landlock
Makefile dependencies as well as related include paths that are
standard for headers in the kernel tree.
Signed-off-by: Guillaume Tucker <guillaume.tucker@collabora.com>
Reported-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
So we have proper counters at the end of a test. We also print the
kselftest header at the end of the test, so we don't mix with the output
of the child process. There is only this one test anyhow.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: John Stultz <jstultz@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
The return value from system() is a waitpid-style integer. Do not return
it directly because with the implicit masking in exit() it will always
return 0. Access it with appropriate macros to really pass on errors.
Fixes: 7290ce1423 ("selftests/timers: Add clocksource-switch test from timetest suite")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: John Stultz <jstultz@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
