Currently we can crash perf record when running in pipe mode, like:
$ perf record ls | perf report
# To display the perf.data header info, please use --header/--header-only options.
#
perf: Segmentation fault
Error:
The - file has no samples!
The callstack of the crash is:
0x0000000000515242 in perf_event__synthesize_event_update_name
3513 ev = event_update_event__new(len + 1, PERF_EVENT_UPDATE__NAME, evsel->id[0]);
(gdb) bt
#0 0x0000000000515242 in perf_event__synthesize_event_update_name
#1 0x00000000005158a4 in perf_event__synthesize_extra_attr
#2 0x0000000000443347 in record__synthesize
#3 0x00000000004438e3 in __cmd_record
#4 0x000000000044514e in cmd_record
#5 0x00000000004cbc95 in run_builtin
#6 0x00000000004cbf02 in handle_internal_command
#7 0x00000000004cc054 in run_argv
#8 0x00000000004cc422 in main
The reason of the crash is that the evsel does not have ids array
allocated and the pipe's synthesize code tries to access it.
We don't force evsel ids allocation when we have single event, because
it's not needed. However we need it when we are in pipe mode even for
single event as a key for evsel update event.
Fixing this by forcing evsel ids allocation event for single event, when
we are in pipe mode.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180302161354.30192-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This first happened with a gcc function, _cpp_lex_token, that has the
usual jumps:
│1159e6c: ↓ jne 115aa32 <_cpp_lex_token@@Base+0xf92>
I.e. jumps to a label inside that function (_cpp_lex_token), and those
works, but also this kind:
│1159e8b: ↓ jne c469be <cpp_named_operator2name@@Base+0xa72>
I.e. jumps to another function, outside _cpp_lex_token, which are not
being correctly handled generating as a side effect references to
ab->offset[] entries that are set to NULL, so to make this code more
robust, check that here.
A proper fix for will be put in place, looking at the function name
right after the '<' token and probably treating this like a 'call'
instruction.
For now just don't draw the arrow.
Reported-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Ingo Molnar <mingo@kernel.org>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Kan Liang <kan.liang@intel.com>
Link: https://lkml.kernel.org/n/tip-5tzvb875ep2sel03aeefgmud@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
On older (e.g. v4.4) kernels, an annoying fallback message can be
observed in 'perf top':
┌─Warning:──────────────────────┐
│fall back to non-overwrite mode│
│ │
│ │
│Press any key... │
└───────────────────────────────┘
The 'perf top' utility has been changed to overwrite mode since commit
ebebbf0823 ("perf top: Switch default mode to overwrite mode").
For older kernels which don't have overwrite mode support, 'perf top'
will fall back to non-overwrite mode and print out the fallback message
using ui__warning(), which needs user's input to close.
The fallback message is not critical for end users. Turning it to debug
message which is printed when running with -vv.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Kan Liang <kan.liang@intel.com>
Cc: Kan Liang <kan.liang@intel.com>
Fixes: ebebbf0823 ("perf top: Switch default mode to overwrite mode")
Link: http://lkml.kernel.org/r/1519669030-176549-1-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The perf kvm still use the legacy interface.
Switch to the new perf_mmap__read_event() interface for perf kvm.
No functional change.
Committer notes:
Tested before and after running:
# perf kvm stat record
On a machine with a kvm guest, then used:
# perf kvm stat report
Before/after results match and look like:
# perf kvm stat record -a sleep 5
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 2.132 MB perf.data.guest (1828 samples) ]
# perf kvm stat report
Analyze events for all VMs, all VCPUs:
VM-EXIT Samples Samples% Time% Min Time Max Time Avg time
IO_INSTRUCTION 258 40.06% 0.08% 3.51us 122.54us 14.87us (+- 6.76%)
MSR_WRITE 178 27.64% 0.01% 0.47us 6.34us 2.18us (+- 4.80%)
EPT_MISCONFIG 148 22.98% 0.03% 3.76us 65.60us 11.22us (+- 8.14%)
HLT 47 7.30% 99.88% 181.69us 249988.06us 102061.36us (+-13.49%)
PAUSE_INSTRUCTION 5 0.78% 0.00% 0.38us 0.79us 0.47us (+-17.05%)
MSR_READ 4 0.62% 0.00% 1.14us 3.33us 2.67us (+-19.35%)
EXTERNAL_INTERRUPT 2 0.31% 0.00% 2.15us 2.17us 2.16us (+- 0.30%)
PENDING_INTERRUPT 1 0.16% 0.00% 2.56us 2.56us 2.56us (+- 0.00%)
PREEMPTION_TIMER 1 0.16% 0.00% 3.21us 3.21us 3.21us (+- 0.00%)
Total Samples:644, Total events handled time:4802790.72us.
#
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1519945751-37786-1-git-send-email-kan.liang@linux.intel.com
[ Changed bool parameters from 0 to 'false', as per Jiri comment ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Currently we can crash perf record when running in pipe mode, like:
$ perf record ls | perf report
# To display the perf.data header info, please use --header/--header-only options.
#
perf: Segmentation fault
Error:
The - file has no samples!
The callstack of the crash is:
0x0000000000515242 in perf_event__synthesize_event_update_name
3513 ev = event_update_event__new(len + 1, PERF_EVENT_UPDATE__NAME, evsel->id[0]);
(gdb) bt
#0 0x0000000000515242 in perf_event__synthesize_event_update_name
#1 0x00000000005158a4 in perf_event__synthesize_extra_attr
#2 0x0000000000443347 in record__synthesize
#3 0x00000000004438e3 in __cmd_record
#4 0x000000000044514e in cmd_record
#5 0x00000000004cbc95 in run_builtin
#6 0x00000000004cbf02 in handle_internal_command
#7 0x00000000004cc054 in run_argv
#8 0x00000000004cc422 in main
The reason of the crash is that the evsel does not have ids array
allocated and the pipe's synthesize code tries to access it.
We don't force evsel ids allocation when we have single event, because
it's not needed. However we need it when we are in pipe mode even for
single event as a key for evsel update event.
Fixing this by forcing evsel ids allocation event for single event, when
we are in pipe mode.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180302161354.30192-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
# perf record -F 200000 sleep 1
warning: Maximum frequency rate (15,000 Hz) exceeded, throttling from 200,000 Hz to 15,000 Hz.
The limit can be raised via /proc/sys/kernel/perf_event_max_sample_rate.
The kernel will lower it when perf's interrupts take too long.
Use --strict-freq to disable this throttling, refusing to record.
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.019 MB perf.data (15 samples) ]
# perf evlist -v
cycles:ppp: size: 112, { sample_period, sample_freq }: 15000, sample_type: IP|TID|TIME|PERIOD, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, enable_on_exec: 1, task: 1, precise_ip: 3, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1
For those wanting that it fails if the desired frequency can't be used:
# perf record --strict-freq -F 200000 sleep 1
error: Maximum frequency rate (15,000 Hz) exceeded.
Please use -F freq option with a lower value or consider
tweaking /proc/sys/kernel/perf_event_max_sample_rate.
#
Suggested-by: Ingo Molnar <mingo@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-oyebruc44nlja499nqkr1nzn@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
There's a problem with relying on backtrace data from 'perf trace' the
way the trace+probe_libc_inet_pton does. This test inserts uprobe within
ping binary and checks that it gets its sample using 'perf trace'.
It also checks it gets proper backtrace from sample and that's where the
issue is.
The 'perf trace' does not sort events (by definition) so it can happen
that it processes the event sample before the ping binary memory map
event. This can (very rarely) happen as proved by this events dump
output (from custom added debug output):
...
7680/7680: [0x7f4e29718000(0x204000) @ 0 fd:00 33611321 4230892504]: r-xp /usr/lib64/libdl-2.17.so
7680/7680: [0x7f4e29502000(0x216000) @ 0 fd:00 33617257 2606846872]: r-xp /usr/lib64/libz.so.1.2.7
(IP, 0x2): 7680/7680: 0x7f4e29c2ed60 period: 1 addr: 0
7680/7680: [0x564842ef0000(0x233000) @ 0 fd:00 83 1989280200]: r-xp /usr/bin/ping
7680/7680: [0x7f4e2aca2000(0x224000) @ 0 fd:00 33611308 1219144940]: r-xp /usr/lib64/ld-2.17.so
...
In this case 'perf trace' fails to resolve the last callchain IP (within
the ping binary) because it does not know about the ping binary memory
map yet and the test fails like this:
PING ::1(::1) 56 data bytes
64 bytes from ::1: icmp_seq=1 ttl=64 time=0.037 ms
--- ::1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.037/0.037/0.037/0.000 ms
0.000 probe_libc:inet_pton:(7f4e29c2ed60))
__GI___inet_pton (/usr/lib64/libc-2.17.so)
getaddrinfo (/usr/lib64/libc-2.17.so)
[0] ([unknown])
FAIL: expected backtrace entry 8 ".*\(.*/bin/ping.*\)$" got "[0] ([unknown])"
Switching the test to use 'perf record' and 'perf script' instead of
'perf trace'.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180301165215.6780-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This first happened with a gcc function, _cpp_lex_token, that has the
usual jumps:
│1159e6c: ↓ jne 115aa32 <_cpp_lex_token@@Base+0xf92>
I.e. jumps to a label inside that function (_cpp_lex_token), and those
works, but also this kind:
│1159e8b: ↓ jne c469be <cpp_named_operator2name@@Base+0xa72>
I.e. jumps to another function, outside _cpp_lex_token, which are not
being correctly handled generating as a side effect references to
ab->offset[] entries that are set to NULL, so to make this code more
robust, check that here.
A proper fix for will be put in place, looking at the function name
right after the '<' token and probably treating this like a 'call'
instruction.
For now just don't draw the arrow.
Reported-by: Ingo Molnar <mingo@kernel.org>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Kan Liang <kan.liang@intel.com>
Link: https://lkml.kernel.org/n/tip-5tzvb875ep2sel03aeefgmud@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
iproute2 print_skbmod() prints the configured ethertype using format 0x%X:
therefore, test 9aa8 systematically fails, because it configures action #4
using ethertype 0x0031, and expects 0x0031 when it reads it back. Changing
the expected value to 0x31 lets the test result 'not ok' become 'ok'.
tested with:
# ./tdc.py -e 9aa8
Test 9aa8: Get a single skbmod action from a list
All test results:
1..1
ok 1 9aa8 Get a single skbmod action from a list
Fixes: cf797ac49b ("tc-testing: Add test cases for police and skbmod")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull x86/pti fixes from Thomas Gleixner:
"Three fixes related to melted spectrum:
- Sync the cpu_entry_area page table to initial_page_table on 32 bit.
Otherwise suspend/resume fails because resume uses
initial_page_table and triggers a triple fault when accessing the
cpu entry area.
- Zero the SPEC_CTL MRS on XEN before suspend to address a
shortcoming in the hypervisor.
- Fix another switch table detection issue in objtool"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/cpu_entry_area: Sync cpu_entry_area to initial_page_table
objtool: Fix another switch table detection issue
x86/xen: Zero MSR_IA32_SPEC_CTRL before suspend
Add a command line arg to suppress tap output. Handy in case
all the tap output is being supplied by the plugins.
Signed-off-by: Brenda J. Butler <bjb@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Daniel Borkmann says:
====================
pull-request: bpf-next 2018-03-03
The following pull-request contains BPF updates for your *net-next* tree.
The main changes are:
1) Extend bpftool to build up CFG information of eBPF programs and add an
option to dump this in DOT format such that this can later be used with
DOT graphic tools (xdot, graphviz, etc) to visualize it. Part of the
analysis performed is sub-program detection and basic-block partitioning,
from Jiong.
2) Multiple enhancements for bpftool's batch mode, more specifically the
parser now understands comments (#), continuation lines (\), and arguments
enclosed between quotes. Also, allow to read from stdin via '-' as input
file, all from Quentin.
3) Improve BPF kselftests by i) unifying the rlimit handling into a helper
that is then used by all tests, and ii) add support for testing tail calls
to test_verifier plus add tests covering all corner cases. The latter is
especially useful for testing JITs, from Daniel.
4) Remove x64 JIT's bpf_flush_icache() since flush_icache_range() is a noop
on x64, from Daniel.
5) Fix one more occasion in BPF samples where we do not detach the BPF program
from the cgroup after completion, from Prashant.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 16c513b134
("selftests: memory-hotplug: silence test command echo")
introduced regression in emit_tests and results in the following
failure when selftests are installed and run. Fix it.
Running tests in memory-hotplug
========================================
./run_kselftest.sh: line 121: @./mem-on-off-test.sh: No such file or
directory
selftests: memory-hotplug [FAIL]
Fixes: 16c513b134 (selftests: memory-hotplug: silence test command echo")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Improve argument parsing from batch input files in order to support
arguments enclosed between single (') or double quotes ("). For example,
this command can now be parsed in batch mode:
bpftool prog dump xlated id 1337 file "/tmp/my file with spaces"
The function responsible for parsing command arguments is copied from
its counterpart in lib/utils.c in iproute2 package.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Add support for continuation lines, such as in the following example:
prog show
prog dump xlated \
id 1337 opcodes
This patch is based after the code for support for continuation lines
from file lib/utils.c from package iproute2.
"Lines" in error messages are renamed as "commands", as we count the
number of commands (but we ignore empty lines, comments, and do not add
continuation lines to the count).
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Replace '#' by '\0' in commands read from batch files in order to avoid
processing the remaining part of the line, thus allowing users to use
comments in the files.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Daniel Borkmann says:
====================
pull-request: bpf 2018-02-28
The following pull-request contains BPF updates for your *net* tree.
The main changes are:
1) Add schedule points and reduce the number of loop iterations
the test_bpf kernel module is performing in order to not hog
the CPU for too long, from Eric.
2) Fix an out of bounds access in tail calls in the ppc64 BPF
JIT compiler, from Daniel.
3) Fix a crash on arm64 on unaligned BPF xadd operations that
could be triggered via interpreter and JIT, from Daniel.
Please not that once you merge net into net-next at some point, there
is a minor merge conflict in test_verifier.c since test cases had
been added at the end in both trees. Resolution is trivial: keep all
the test cases from both trees.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Add bash completion for the "visual" keyword used for dumping the CFG of
eBPF programs with bpftool. Make sure we only complete with this keyword
when we dump "xlated" (and not "jited") instructions.
Acked-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch adds new command-line option for visualizing the xlated eBPF
sequence.
Documentations are updated accordingly.
Usage:
bpftool prog dump xlated id 2 visual
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch let bpftool print .dot graph file into stdout.
This graph is generated by the following steps:
- iterate through the function list.
- generate basic-block(BB) definition for each BB in the function.
- draw out edges to connect BBs.
This patch is the initial support, the layout and decoration of the .dot
graph could be improved.
Also, it will be useful if we could visualize some performance data from
static analysis.
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch adds out edges for each basic-block. We will need these out
edges to finish the .dot graph drawing.
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch partition basic-block for each function in the CFG. The
algorithm is simple, we identify basic-block head in a first traversal,
then second traversal to identify the tail.
We could build extended basic-block (EBB) in next steps. EBB could make the
graph more readable when the eBPF sequence is big.
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch detect all sub-programs from the eBPF sequence and keep the
information in the new CFG data structure.
The detection algorithm is basically the same as the one in verifier except
we need to use insn->off instead of insn->imm to get the pc-relative call
offset. Because verifier has modified insn->off/insn->imm during finishing
the verification.
Also, we don't need to do some sanity checks as verifier has done them.
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch factors out those code of dumping xlated eBPF instructions into
xlated_dumper.[h|c].
They are quite independent dumper functions, so better to be kept
separately.
New dumper support will be added in later patches in this set.
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add a better description to the summary for multipath tests. e.g.,
INFO: Running IPv6 multipath tests
TEST: ECMP [PASS]
INFO: Expected ratio 1.00 Measured ratio 1.02
TEST: Weighted MP 2:1 [PASS]
INFO: Expected ratio 2.00 Measured ratio 2.02
TEST: Weighted MP 11:45 [PASS]
INFO: Expected ratio 4.09 Measured ratio 4.03
Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
On Debian jessie ping can not handle IPv6 addresses so the command
fails. Use PING6 which is set to ping6.
Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If the packet stats have a difference of 0, the test output shows:
INFO: Expected ratio 2.00 Measured ratio
Runtime error (func=(main), adr=9): Divide by zero
(standard_in) 2: syntax error
(standard_in) 1: syntax error
./router_multipath.sh: line 187: test: : integer expression expected
TEST: Multipath [FAIL]
Too large discrepancy between expected and measured ratios
Handle the 0 and display a cleaner message:
INFO: Running IPv6 multipath tests
TEST: Multipath [FAIL]
Packet difference is 0
Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
