Set up generic support in bpf_tracing.h for up to 7 syscall arguments
tracing with BPF_KSYSCALL, which seems to be the limit according to
syscall(2) manpage. Also change the way that syscall convention is
specified to be more explicit. Subsequent patches will adjust and define
proper per-architecture syscall conventions.
__PT_PARM1_SYSCALL_REG through __PT_PARM6_SYSCALL_REG is added
temporarily to keep everything working before each architecture has
syscall reg tables defined. They will be removed afterwards.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Alan Maguire <alan.maguire@oracle.com> # arm64
Link: https://lore.kernel.org/bpf/20230120200914.3008030-13-andrii@kernel.org
Update uprobe_autoattach selftest to validate architecture-specific
argument passing through registers. Use new BPF_UPROBE and
BPF_URETPROBE, and construct both BPF-side and user-space side in such
a way that for different architectures we are fetching and checking
different number of arguments, matching architecture-specific limit of
how many registers are available for argument passing.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Alan Maguire <alan.maguire@oracle.com> # arm64
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com> # s390x
Link: https://lore.kernel.org/bpf/20230120200914.3008030-12-andrii@kernel.org
Add BPF_UPROBE and BPF_URETPROBE macros, aliased to BPF_KPROBE and
BPF_KRETPROBE, respectively. This makes uprobe-based BPF program code
much less confusing, especially to people new to tracing, at no cost in
terms of maintainability. We'll use this macro in selftests in
subsequent patch.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230120200914.3008030-11-andrii@kernel.org
Add BPF_KPROBE() and PT_REGS_PARMx() support for up to 8 arguments, if
target architecture supports this. Currently all architectures are
limited to only 5 register-placed arguments, which is limiting even on
x86-64.
This patch adds generic macro machinery to support up to 8 arguments
both when explicitly fetching it from pt_regs through PT_REGS_PARMx()
macros, as well as more ergonomic access in BPF_KPROBE().
Also, for i386 architecture we now don't have to define fake PARM4 and
PARM5 definitions, they will be generically substituted, just like for
PARM6 through PARM8.
Subsequent patches will fill out architecture-specific definitions,
where appropriate.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Alan Maguire <alan.maguire@oracle.com> # arm64
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com> # s390x
Link: https://lore.kernel.org/bpf/20230120200914.3008030-2-andrii@kernel.org
In commit 537c3f66ea ("selftests/bpf: add generic BPF program tester-loader"),
a new mechanism was added to the BPF selftest framework to allow testsuites to
use macros to define expected failing testcases.
This allows any testsuite which tests verification failure to remove a good
amount of boilerplate code. This patch updates the task_kfunc selftest suite
to use these new macros.
Signed-off-by: David Vernet <void@manifault.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20230120021844.3048244-1-void@manifault.com
To be used for verification of driver implementations. Note that
the skb path is gone from the series, but I'm still keeping the
implementation for any possible future work.
$ xdp_hw_metadata <ifname>
On the other machine:
$ echo -n xdp | nc -u -q1 <target> 9091 # for AF_XDP
$ echo -n skb | nc -u -q1 <target> 9092 # for skb
Sample output:
# xdp
xsk_ring_cons__peek: 1
0x19f9090: rx_desc[0]->addr=100000000008000 addr=8100 comp_addr=8000
rx_timestamp_supported: 1
rx_timestamp: 1667850075063948829
0x19f9090: complete idx=8 addr=8000
# skb
found skb hwtstamp = 1668314052.854274681
Decoding:
# xdp
rx_timestamp=1667850075.063948829
$ date -d @1667850075
Mon Nov 7 11:41:15 AM PST 2022
$ date
Mon Nov 7 11:42:05 AM PST 2022
# skb
$ date -d @1668314052
Sat Nov 12 08:34:12 PM PST 2022
$ date
Sat Nov 12 08:37:06 PM PST 2022
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Anatoly Burakov <anatoly.burakov@intel.com>
Cc: Alexander Lobakin <alexandr.lobakin@intel.com>
Cc: Magnus Karlsson <magnus.karlsson@gmail.com>
Cc: Maryam Tahhan <mtahhan@redhat.com>
Cc: xdp-hints@xdp-project.net
Cc: netdev@vger.kernel.org
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230119221536.3349901-18-sdf@google.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
The perf test named “build id cache operations” skips with below error
on some distros:
<<>>
78: build id cache operations :
test child forked, pid 111101
WARNING: wine not found. PE binaries will not be run.
test binaries: /tmp/perf.ex.SHA1.PKz /tmp/perf.ex.MD5.Gt3 ./tests/shell/../pe-file.exe
DEBUGINFOD_URLS=
Adding 4abd406f041feb4f10ecde3fc30fd0639e1a91cb /tmp/perf.ex.SHA1.PKz: Ok
build id: 4abd406f041feb4f10ecde3fc30fd0639e1a91cb
./tests/shell/buildid.sh: 69: ./tests/shell/buildid.sh: Bad substitution
test child finished with -2
build id cache operations: Skip
<<>>
The test script "tests/shell/buildid.sh" uses some of the string
substitution ways which are supported in bash, but not in "sh" or other
shells. Above error on line number 69 that reports "Bad substitution"
is:
<<>>
link=${build_id_dir}/.build-id/${id:0:2}/${id:2}
<<>>
Here the way of getting first two characters from id ie, ${id:0:2} and
similarly expressions like ${id:2} is not recognised in "sh". So the
line errors and instead of hitting failure, the test gets skipped as
shown in logs. So the syntax issue causes test not to be executed in
such cases. Similarly usage : "${@: -1}" [ to pick last argument passed
to a function] in “test_record” doesn’t work in all distros.
Fix this by using alternative way with shell substitution to pick
required characters from the string. Also fix the usage of “${@: -1}” to
work in all cases.
Another usage in “test_record” is:
<<>>
${perf} record --buildid-all -o ${data} $@ &> ${log}
<<>>
This causes the 'perf record' to start in background and Results in the
data file not being created by the time "check" function is invoked.
Below log shows 'perf record' result getting displayed after the call to
"check" function.
<<>>
running: perf record /tmp/perf.ex.SHA1.EAU
build id: 4abd406f041feb4f10ecde3fc30fd0639e1a91cb
link: /tmp/perf.debug.mLT/.build-id/4a/bd406f041feb4f10ecde3fc30fd0639e1a91cb
failed: link /tmp/perf.debug.mLT/.build-id/4a/bd406f041feb4f10ecde3fc30fd0639e1a91cb does not exist
test child finished with -1
build id cache operations: FAILED!
root@machine:~/athira/linux/tools/perf# Couldn't synthesize bpf events.
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.010 MB /tmp/perf.data.bFF ]
<<>>
Fix this by redirecting output instead of using “&” which starts the
command in background.
Reviewed-by: David Laight <David.Laight@ACULAB.COM>
Signed-off-by: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Tested-by: Disha Goel <disgoel@linux.ibm.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nageswara R Sastry <rnsastry@linux.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lore.kernel.org/r/20230119142719.32628-1-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
BPF filtering tests can sometime fail. Running the test in verbose mode
shows the following:
$ sudo perf test 42
42: BPF filter :
42.1: Basic BPF filtering : FAILED!
42.2: BPF pinning : Skip
42.3: BPF prologue generation : Skip
$ perf --version
perf version 4.18.0-425.3.1.el8.ppc64le
$ sudo perf test -v 42
42: BPF filter :
42.1: Basic BPF filtering :
--- start ---
test child forked, pid 711060
...
bpf: config 'func=do_epoll_wait' is ok
Looking at the vmlinux_path (8 entries long)
Using /usr/lib/debug/lib/modules/4.18.0-425.3.1.el8.ppc64le/vmlinux for symbols
Open Debuginfo file: /usr/lib/debug/.build-id/81/56f5a07f92ccb62c5600ba0e4aacfb5f3a7534.debug
Try to find probe point from debuginfo.
Matched function: do_epoll_wait [4ef8cb0]
found inline addr: 0xc00000000061dbe4
Probe point found: __se_compat_sys_epoll_pwait+196
found inline addr: 0xc00000000061d9f4
Probe point found: __se_sys_epoll_pwait+196
found inline addr: 0xc00000000061d824
Probe point found: __se_sys_epoll_wait+36
Found 3 probe_trace_events.
Opening /sys/kernel/tracing//kprobe_events write=1
...
BPF filter result incorrect, expected 56, got 56 samples
test child finished with -1
---- end ----
BPF filter subtest 1: FAILED!
The statement above about the result being incorrect looks weird, and it
is due to that particular perf build missing commit 3e11300cdf
("perf test: Fix bpf test sample mismatch reporting"). In reality, due
to commit 4b04e0decd ("perf test: Fix basic bpf filtering test"),
perf expects there to be 56*3 samples.
However, the number of samples we receive is going to be dependent on
where the probes are installed, which is dependent on where
do_epoll_wait gets inlined. On s390x, it looks like probes at all the
inlined locations are hit. But, that is not the case on ppc64le.
Fix this by switching the test to instead use the syscall tracepoint.
This ensures that we will only ever install a single event enabling us
to reliably determine the sample count.
Reported-by: Disha Goel <disgoel@linux.vnet.ibm.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: bpf@vger.kernel.org
Link: http://lore.kernel.org/lkml/20230123083224.276404-1-naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
There are some edge cases around estimated timestamps that can result
in them going backwards.
One is that after a discontinuity, the last used timestamp is set to 0.
The duration of the next range is then subtracted which could result in
an earlier timestamp than the last instruction. Fix this by not
resetting the last timestamp used on a discontinuity, and make sure that
new estimated timestamps are clamped to be later than that.
Another case is that estimated timestamps could compound over time to
end up being more than the next real timestamp in the trace. Fix this by
clamping the estimates in cs_etm_decoder__do_soft_timestamp() to be no
later than it.
cs_etm_decoder__do_soft_timestamp() also updated next_cs_timestamp,
which meant that the next real timestamp was lost and not stored
anywhere. Fix that by only updating cs_timestamp for estimates and keep
next_cs_timestamp untouched.
Finally, use next_cs_timestamp to signify if a timestamp has been
received previously. Because cs_timestamp has the first range
subtracted, it could technically go to 0 which would break the logic.
Testing
=======
It can be verified that timestamps don't go backwards when tracing on a
single core with the following commands. Across multiple cores it's
expected that timestamps are interleaved:
$ perf record -e cs_etm/@tmc_etr0/k -C 4 taskset -c 4 sleep 1
$ perf script --itrace=i1ns --ns -Fcomm,tid,pid,time,cpu,event,ip,sym,addr,symoff,flags,callindent > itrace
$ sed 's/://g' itrace | awk -F ' ' ' { print $4 } ' | awk '{ if ($1 < prev) { print "line:" NR " " $0 } {prev=$1}}'
Reported-by: Tanmay Jagdale <tanmay@marvell.com>
Signed-off-by: James Clark <james.clark@arm.com>
Acked-by: Suzuki Poulouse <suzuki.poulose@arm.com>
Tested-by: Tanmay Jagdale <tanmay@marvell.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Bharat Bhushan <bbhushan2@marvell.com>
Cc: George Cherian <gcherian@marvell.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Linu Cherian <lcherian@marvell.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Cc: Will Deacon <will@kernel.org>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230120143702.4035046-9-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
If virtual timestamps are detected, set sample time field accordingly,
otherwise warn the user that the samples will not include accurate
time data.
| Test notes (FEAT_TRF platform)
|
| $ ./perf record -e cs_etm//u -a -- sleep 4
| $ ./perf script --fields +time
| perf 422 [000] 163.375100: 1 branches:uH: 0 [unknown] ([unknown])
| perf 422 [000] 163.375100: 1 branches:uH: ffffb8009544 ioctl+0x14 (/lib/aarch64-linux-gnu/libc-2.27.so)
| perf 422 [000] 163.375100: 1 branches:uH: aaaaab6bebf4 perf_evsel__run_ioctl+0x90 (/home/german/linux/tools/perf/perf)
| [...]
| perf 422 [000] 167.393100: 1 branches:uH: aaaaab6bda00 __xyarray__entry+0x74 (/home/german/linux/tools/perf/perf)
| perf 422 [000] 167.393099: 1 branches:uH: aaaaab6bda0c __xyarray__entry+0x80 (/home/german/linux/tools/perf/perf)
| perf 422 [000] 167.393099: 1 branches:uH: ffffb8009538 ioctl+0x8 (/lib/aarch64-linux-gnu/libc-2.27.so)
|
| The time from the first sample to the last sample is 4 seconds
Now that times are converted to nanoseconds, also try to estimate the
timestamps more accurately be dividing by some fixed value for
instructions per ns. This prevents long ranges from being estimated
too far in the past than would be realistic.
Signed-off-by: German Gomez <german.gomez@arm.com>
Acked-by: Suzuki Poulouse <suzuki.poulose@arm.com>
Tested-by: Tanmay Jagdale <tanmay@marvell.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Bharat Bhushan <bbhushan2@marvell.com>
Cc: George Cherian <gcherian@marvell.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Linu Cherian <lcherian@marvell.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Cc: Will Deacon <will@kernel.org>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230120143702.4035046-8-james.clark@arm.com
Signed-off-by: James Clark <james.clark@arm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Create a sensible name for .plt entries with no symbol.
Example:
Before:
$ perf test --dso /usr/lib/x86_64-linux-gnu/libc.so.6 -vv Symbols 2>/tmp/cmp1.txt
After:
$ perf test --dso /usr/lib/x86_64-linux-gnu/libc.so.6 -vv Symbols 2>/tmp/cmp2.txt
$ diff /tmp/cmp1.txt /tmp/cmp2.txt
4c4
< test child forked, pid 53043
---
> test child forked, pid 54372
23,62c23,62
< 280f0-28100 g @plt
< 28100-28110 g @plt
< 28110-28120 g @plt
< 28120-28130 g @plt
< 28130-28140 g @plt
< 28140-28150 g @plt
< 28150-28160 g @plt
< 28160-28170 g @plt
< 28170-28180 g @plt
< 28180-28190 g @plt
< 28190-281a0 g @plt
< 281a0-281b0 g @plt
< 281b0-281c0 g @plt
< 281c0-281d0 g @plt
< 281d0-281e0 g @plt
< 281e0-281f0 g @plt
< 281f0-28200 g @plt
< 28200-28210 g @plt
< 28210-28220 g @plt
< 28220-28230 g @plt
< 28230-28240 g @plt
< 28240-28250 g @plt
< 28250-28260 g @plt
< 28260-28270 g @plt
< 28270-28280 g @plt
< 28280-28290 g @plt
< 28290-282a0 g @plt
< 282a0-282b0 g @plt
< 282b0-282c0 g @plt
< 282c0-282d0 g @plt
< 282d0-282e0 g @plt
< 282e0-282f0 g @plt
< 282f0-28300 g @plt
< 28300-28310 g @plt
< 28310-28320 g @plt
< 28320-28330 g @plt
< 28330-28340 g @plt
< 28340-28350 g @plt
< 28350-28360 g @plt
< 28360-28370 g @plt
---
> 280f0-28100 g offset_0x280f0@plt
> 28100-28110 g offset_0x28100@plt
> 28110-28120 g offset_0x28110@plt
> 28120-28130 g offset_0x28120@plt
> 28130-28140 g offset_0x28130@plt
> 28140-28150 g offset_0x28140@plt
> 28150-28160 g offset_0x28150@plt
> 28160-28170 g offset_0x28160@plt
> 28170-28180 g offset_0x28170@plt
> 28180-28190 g offset_0x28180@plt
> 28190-281a0 g offset_0x28190@plt
> 281a0-281b0 g offset_0x281a0@plt
> 281b0-281c0 g offset_0x281b0@plt
> 281c0-281d0 g offset_0x281c0@plt
> 281d0-281e0 g offset_0x281d0@plt
> 281e0-281f0 g offset_0x281e0@plt
> 281f0-28200 g offset_0x281f0@plt
> 28200-28210 g offset_0x28200@plt
> 28210-28220 g offset_0x28210@plt
> 28220-28230 g offset_0x28220@plt
> 28230-28240 g offset_0x28230@plt
> 28240-28250 g offset_0x28240@plt
> 28250-28260 g offset_0x28250@plt
> 28260-28270 g offset_0x28260@plt
> 28270-28280 g offset_0x28270@plt
> 28280-28290 g offset_0x28280@plt
> 28290-282a0 g offset_0x28290@plt
> 282a0-282b0 g offset_0x282a0@plt
> 282b0-282c0 g offset_0x282b0@plt
> 282c0-282d0 g offset_0x282c0@plt
> 282d0-282e0 g offset_0x282d0@plt
> 282e0-282f0 g offset_0x282e0@plt
> 282f0-28300 g offset_0x282f0@plt
> 28300-28310 g offset_0x28300@plt
> 28310-28320 g offset_0x28310@plt
> 28320-28330 g offset_0x28320@plt
> 28330-28340 g offset_0x28330@plt
> 28340-28350 g offset_0x28340@plt
> 28350-28360 g offset_0x28350@plt
> 28360-28370 g offset_0x28360@plt
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20230120123456.12449-9-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf expands the _init symbol over .plt because there are no PLT symbols
at that point, but then dso__synthesize_plt_symbols() creates them.
Fix by truncating the previous symbol and inserting a symbol for .plt
header.
Example:
Before:
$ perf test --dso `which uname` -v Symbols
74: Symbols :
--- start ---
test child forked, pid 191028
Problems creating module maps, continuing anyway...
Testing /usr/bin/uname
Overlapping symbols:
2000-25f0 g _init
2040-2050 g free@plt
test child finished with -1
---- end ----
Symbols: FAILED!
$ perf test --dso `which uname` -vv Symbols 2>/tmp/cmp1.txt
After:
$ perf test --dso `which uname` -v Symbols
74: Symbols :
--- start ---
test child forked, pid 194291
Testing /usr/bin/uname
test child finished with 0
---- end ----
Symbols: Ok
$ perf test --dso `which uname` -vv Symbols 2>/tmp/cmp2.txt
$ diff /tmp/cmp1.txt /tmp/cmp2.txt
4,5c4
< test child forked, pid 191031
< Problems creating module maps, continuing anyway...
---
> test child forked, pid 194296
9c8,9
< 2000-25f0 g _init
---
> 2000-2030 g _init
> 2030-2040 g .plt
100,103c100
< Overlapping symbols:
< 2000-25f0 g _init
< 2040-2050 g free@plt
< test child finished with -1
---
> test child finished with 0
105c102
< Symbols: FAILED!
---
> Symbols: Ok
$
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20230120123456.12449-8-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
