We'll continue reading its details from tracefs as we need it, but
preallocate the whole thing otherwise we may realloc and end up with
pointers to the previous buffer.
I.e. in an upcoming algorithm we'll look for syscalls that have function
signatures that are similar to a given syscall to see if we can reuse
its BPF augmenter, so we may be at syscall 42, having a 'struct syscall'
pointing to that slot in trace->syscalls.table[] and try to read the
slot for an yet unread syscall, which would realloc that table to read
the info for syscall 43, say, which would trigger a realoc of
trace->syscalls.table[], and then the pointer we had for syscall 42
would be pointing to the previous block of memory. b00m.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-m3cjzzifibs13imafhkk77a0@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We iterate thru the syscall table produced from the kernel syscall
tables reading info, propagate the error and add to the debug message.
This helps in fixing further bugs, such as failing to read the
"sendfile" syscall info when it really should try the aliasm
"sendfile64".
Problems reading syscall 40: 2 (No such file or directory)(sendfile) information
# grep sendfile /tmp/build/perf/arch/x86/include/generated/asm/syscalls_64.c
[40] = "sendfile",
#
I.e. in the tracefs format file for the syscall tracepoints we have it
as sendfile64:
# find /sys -type f -name format | grep sendfile
/sys/kernel/debug/tracing/events/syscalls/sys_enter_sendfile64/format
/sys/kernel/debug/tracing/events/syscalls/sys_exit_sendfile64/format
#
But as "sendfile" in the file used to build the syscall table used in
perf:
$ grep sendfile arch/x86/entry/syscalls/syscall_64.tbl
40 common sendfile __x64_sys_sendfile64
$
So we need to add, in followup patches, aliases in 'perf trace' syscall
data structures to cope with thie.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-w3eluap63x9je0bb8o3t79tz@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
As we invalidate the fd->pathname table in the SCA_CLOSE_FD beautifier,
if we don't have it we may end up keeping an fd->pathname association
that then gets misprinted.
The previous behaviour continues when the close() syscall is enabled,
which may still be a a problem if we lose records (i.e. we may lose a
'close' record and then get that fd reused by socket()) but then the
tool will notify that records are being lost and the user will be warned
that some of the heuristics will fall apart.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-b7t6h8sq9lebemvfy2zh3qq1@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We already had a beautifier for an augmented sockaddr payload, but that
was when we were hooking on each syscalls:sys_enter_foo tracepoints,
since now we're almost doing that by doing a tail call from
raw_syscalls:sys_enter, its almost the same, we can reuse it straight
away.
# perf trace -e connec* ssh www.bla.com
connect(3</var/lib/sss/mc/passwd>, { .family: PF_LOCAL, path: /var/run/nscd/socket }, 0x6e) = -1 ENOENT (No such file or directory)
connect(3</var/lib/sss/mc/passwd>, { .family: PF_LOCAL, path: /var/run/nscd/socket }, 0x6e) = -1 ENOENT (No such file or directory)
connect(4<socket:[16604782]>, { .family: PF_LOCAL, path: /var/lib/sss/pipes/nss }, 0x6e) = 0
connect(7, { .family: PF_LOCAL, path: /var/run/nscd/socket }, 0x6e) = -1 ENOENT (No such file or directory)
connect(7, { .family: PF_LOCAL, path: /var/run/nscd/socket }, 0x6e) = -1 ENOENT (No such file or directory)
connect(5</etc/hosts>, { .family: PF_LOCAL, path: /var/run/nscd/socket }, 0x6e) = -1 ENOENT (No such file or directory)
connect(5</etc/hosts>, { .family: PF_LOCAL, path: /var/run/nscd/socket }, 0x6e) = -1 ENOENT (No such file or directory)
connect(5</etc/hosts>, { .family: PF_INET, port: 53, addr: 192.168.44.1 }, 0x10) = 0
connect(5</etc/hosts>, { .family: PF_INET, port: 22, addr: 146.112.61.108 }, 0x10) = 0
connect(5</etc/hosts>, { .family: PF_INET6, port: 22, addr: ::ffff:146.112.61.108 }, 0x1c) = 0
^C#
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-5xkrbcpjsgnr3zt1aqdd7nvc@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Starting with the renameat and renameat2 syscall, that both receive as
second and fourth parameters a pathname:
# perf trace -e rename* mv one ANOTHER
LLVM: dumping /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o
mv: cannot stat 'one': No such file or directory
renameat2(AT_FDCWD, "one", AT_FDCWD, "ANOTHER", RENAME_NOREPLACE) = -1 ENOENT (No such file or directory)
#
Since the per CPU scratch buffer map has space for two maximum sized
pathnames, the verifier is satisfied that there will be no overrun.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-x2uboyg5kx2wqeru288209b6@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Trying to control what arguments to copy, which ones were strings, etc
all from userspace via maps went nowhere, lots of difficulties to get
the verifier satisfied, so use what the fine BPF guys designed for such
a syscall handling mechanism: bpf_tail_call + BPF_MAP_TYPE_PROG_ARRAY.
The series leading to this should have explained it thoroughly, but the
end result, explained via gdb should help understand this:
Breakpoint 1, syscall_arg__scnprintf_filename (bf=0xc002b1 "", size=2031, arg=0x7fffffff7970) at builtin-trace.c:1268
1268 {
(gdb) n
1269 unsigned long ptr = arg->val;
(gdb) n
1271 if (arg->augmented.args)
(gdb) n
1272 return syscall_arg__scnprintf_augmented_string(arg, bf, size);
(gdb) s
syscall_arg__scnprintf_augmented_string (arg=0x7fffffff7970, bf=0xc002b1 "", size=2031) at builtin-trace.c:1251
1251 {
(gdb) n
1252 struct augmented_arg *augmented_arg = arg->augmented.args;
(gdb) n
1253 size_t printed = scnprintf(bf, size, "\"%.*s\"", augmented_arg->size, augmented_arg->value);
(gdb) n
1258 int consumed = sizeof(*augmented_arg) + augmented_arg->size;
(gdb) p bf
$1 = 0xc002b1 "\"/etc/ld.so.cache\""
(gdb) bt
#0 syscall_arg__scnprintf_augmented_string (arg=0x7fffffff7970, bf=0xc002b1 "\"/etc/ld.so.cache\"", size=2031) at builtin-trace.c:1258
#1 0x0000000000492634 in syscall_arg__scnprintf_filename (bf=0xc002b1 "\"/etc/ld.so.cache\"", size=2031, arg=0x7fffffff7970) at builtin-trace.c:1272
#2 0x0000000000493cd7 in syscall__scnprintf_val (sc=0xc0de68, bf=0xc002b1 "\"/etc/ld.so.cache\"", size=2031, arg=0x7fffffff7970, val=140737354091036) at builtin-trace.c:1689
#3 0x000000000049404f in syscall__scnprintf_args (sc=0xc0de68, bf=0xc002a7 "AT_FDCWD, \"/etc/ld.so.cache\"", size=2041, args=0x7ffff6cbf1ec "\234\377\377\377", augmented_args=0x7ffff6cbf21c, augmented_args_size=28, trace=0x7fffffffa170,
thread=0xbff940) at builtin-trace.c:1756
#4 0x0000000000494a97 in trace__sys_enter (trace=0x7fffffffa170, evsel=0xbe1900, event=0x7ffff6cbf1a0, sample=0x7fffffff7b00) at builtin-trace.c:1975
#5 0x0000000000496ff1 in trace__handle_event (trace=0x7fffffffa170, event=0x7ffff6cbf1a0, sample=0x7fffffff7b00) at builtin-trace.c:2685
#6 0x0000000000497edb in __trace__deliver_event (trace=0x7fffffffa170, event=0x7ffff6cbf1a0) at builtin-trace.c:3029
#7 0x000000000049801e in trace__deliver_event (trace=0x7fffffffa170, event=0x7ffff6cbf1a0) at builtin-trace.c:3056
#8 0x00000000004988de in trace__run (trace=0x7fffffffa170, argc=2, argv=0x7fffffffd660) at builtin-trace.c:3258
#9 0x000000000049c2d3 in cmd_trace (argc=2, argv=0x7fffffffd660) at builtin-trace.c:4220
#10 0x00000000004dcb6c in run_builtin (p=0xa18e00 <commands+576>, argc=5, argv=0x7fffffffd660) at perf.c:304
#11 0x00000000004dcdd9 in handle_internal_command (argc=5, argv=0x7fffffffd660) at perf.c:356
#12 0x00000000004dcf20 in run_argv (argcp=0x7fffffffd4bc, argv=0x7fffffffd4b0) at perf.c:400
#13 0x00000000004dd28c in main (argc=5, argv=0x7fffffffd660) at perf.c:522
(gdb)
(gdb) continue
Continuing.
openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
Now its a matter of automagically assigning the BPF programs copying
syscall arg pointers to functions that are "open"-like (i.e. that need
only the first syscall arg copied as a string), or "openat"-like (2nd
arg, etc).
End result in tool output:
# perf trace -e open* ls /tmp/notthere
LLVM: dumping /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o
openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib64/libselinux.so.1", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib64/libcap.so.2", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib64/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib64/libpcre2-8.so.0", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib64/libdl.so.2", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib64/libpthread.so.0", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/usr/share/locale/locale.alias", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/usr/share/locale/en_US.UTF-8/LC_MESSAGES/coreutils.mo", O_RDONLY) = ls: cannot access '/tmp/notthere'-1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/share/locale/en_US.utf8/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/share/locale/en_US/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/share/locale/en.UTF-8/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/share/locale/en.utf8/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/share/locale/en/LC_MESSAGES/coreutils.mo", O_RDONLY: No such file or directory) =
-1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/share/locale/en_US.UTF-8/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/share/locale/en_US.utf8/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/share/locale/en_US/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/share/locale/en.UTF-8/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/share/locale/en.utf8/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/share/locale/en/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
#
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-snc7ry99cl6r0pqaspjim98x@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
So, we use a PERF_COUNT_SW_BPF_OUTPUT to output the augmented sys_enter
payload, i.e. to output more than just the raw syscall args, and if
something goes wrong when handling an unfiltered syscall, we bail out
and just return 1 in the bpf program associated with
raw_syscalls:sys_enter, meaning, don't filter that tracepoint, in which
case what will appear in the perf ring buffer isn't the BPF_OUTPUT
event, but the original raw_syscalls:sys_enter event with its normal
payload.
Now that we're switching to using a bpf_tail_call +
BPF_MAP_TYPE_PROG_ARRAY we're going to use this in the common case, so a
bug where raw_syscalls:sys_enter wasn't being handled by
trace__sys_enter() surfaced and for that case, instead of using the
strace-like augmenter (trace__sys_enter()), we continued to use the
normal generic tracepoint handler:
(gdb) p evsel
$2 = (struct perf_evsel *) 0xc03e40
(gdb) p evsel->name
$3 = 0xbc56c0 "raw_syscalls:sys_enter"
(gdb) p ((struct perf_evsel *) 0xc03e40)->name
$4 = 0xbc56c0 "raw_syscalls:sys_enter"
(gdb) p ((struct perf_evsel *) 0xc03e40)->handler
$5 = (void *) 0x495eb3 <trace__event_handler>
This resulted in this:
0.027 raw_syscalls:sys_enter:NR 12 (0, 7fcfcac64c9b, 4d, 7fcfcac64c9b, 7fcfcac6ce00, 19)
... [continued]: brk()) = 0x563b88677000
I.e. only the sys_exit tracepoint was being properly handled, but since
the sys_enter went to the generic trace__event_handler() we printed it
using libtraceevent's formatter instead of 'perf trace's strace-like
one.
Fix it by setting trace__sys_enter() as the handler for
raw_syscalls:sys_enter and setup the tp_field tracepoint field
accessors.
Now, to test it we just make raw_syscalls:sys_enter return 1 right after
checking if the pid is filtered, making it not use
bpf_perf_output_event() but rather ask for the tracepoint not to be
filtered and the result is the expected one:
brk(NULL) = 0x556f42d6e000
I.e. raw_syscalls:sys_enter returns 1, gets handled by
trace__sys_enter() and gets it combined with the raw_syscalls:sys_exit
in a strace-like way.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-0mkocgk31nmy0odknegcby4z@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
I.e. look for "syscalls_sys_enter" and "syscalls_sys_exit" BPF maps of
type PROG_ARRAY and populate it with the handlers as specified per
syscall, for now only 'open' is wiring it to something, in time all
syscalls that need to copy arguments entering a syscall or returning
from one will set these to the right handlers, reusing when possible
pre-existing ones.
Next step is to use bpf_tail_call() into that.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-t0p4u43i9vbpzs1xtowna3gb@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This is a step in the direction of being able to use a
BPF_MAP_TYPE_PROG_ARRAY to handle syscalls that need to copy pointer
payloads in addition to the raw tracepoint syscall args.
There is a first example in
tools/perf/examples/bpf/augmented_raw_syscalls.c for the 'open' syscall.
Next step is to introduce the prog array map and use this 'open'
augmenter, then use that augmenter in other syscalls that also only copy
the first arg as a string, and then show how to use with a syscall that
reads more than one filename, like 'rename', etc.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-pys4v57x5qqrybb4cery2mc8@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Will be used to assign to syscalls that don't need augmentation, i.e.
those with just integer args.
All syscalls will be in a BPF_MAP_TYPE_PROG_ARRAY, and the
bpf_tail_call() keyed by the syscall id will either find nothing in
place, which means the syscall is being filtered, or a function that
will either add things like filenames to the ring buffer, right after
the raw syscall args, or be this unaugmented handler that will just
return 1, meaning don't filter the original
raw_syscalls:sys_{enter,exit} tracepoint.
For now it is not really being used, this is just leg work to break the
patch into smaller pieces.
It introduces a trace__find_bpf_program_by_title() helper that in turn
uses libbpf's bpf_object__find_program_by_title() on the BPF object with
the __augmented_syscalls__ map. "title" is how libbpf calls the SEC()
argument for functions, i.e. the ELF section that follows a convention
to specify what BPF program (a function with this SEC() marking) should
be connected to which tracepoint, kprobes, etc.
In perf anything that is of the form SEC("sys:event_name") will be
connected to that tracepoint by perf's BPF loader.
In this case its something that will be bpf_tail_call()ed from either
the "raw_syscalls:sys_enter" or "raw_syscall:sys_exit" tracepoints, so
its named "!raw_syscalls:unaugmented" to convey that idea, i.e. its not
going to be directly attached to a tracepoint, thus it starts with a
"!".
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-meucpjx2u0slpkayx56lxqq6@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
With BPF_MAP_TYPE_PROG_ARRAY + bpf_tail_call() we want to have BPF
programs, i.e. functions in a object file that perf's BPF loader
shouldn't try to attach to anything, i.e. "!syscalls:sys_enter_open"
should just stay there, not be attached to a tracepoint with that name,
it'll be used by, for instance, 'perf trace' to associate with syscalls
that copy, in addition to the syscall raw args, a filename pointed by
the first arg, i.e. multiple syscalls that need copying the same pointer
arg in the same way, as a filename, for instance, will share the same
BPF program/function.
Right now when perf's BPF loader sees a function with a name
"sys:name" it'll look for a tracepoint and will associate that BPF
program with it, say:
SEC("raw_syscalls:sys_enter")
int sys_enter(struct syscall_enter_args *args)
{
//SNIP
}
Will crate a perf_evsel tracepoint event and then associate with it that
BPF program.
This convention at some point will switch to the one used by the BPF
loader in libbpf, but to experiment with BPF_MAP_TYPE_PROG_ARRAY in
'perf trace' lets do this, that will not require changing too much
stuff.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-lk6dasjr1yf9rtvl292b2hpc@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When building our local version of perf with MSAN (Memory Sanitizer) and
running the perf record command, MSAN throws a use of uninitialized
value warning in "tools/perf/util/util.c:333:6".
This warning stems from the "buf" variable being passed into "write".
It originated as the variable "ev" with the type union perf_event*
defined in the "perf_event__synthesize_attr" function in
"tools/perf/util/header.c".
In the "perf_event__synthesize_attr" function they allocate space with a malloc
call using ev, then go on to only assign some of the member variables before
passing "ev" on as a parameter to the "process" function therefore "ev"
contains uninitialized memory. Changing the malloc call to zalloc to initialize
all the members of "ev" which gets rid of the warning.
To reproduce this warning, build perf by running:
make -C tools/perf CLANG=1 CC=clang EXTRA_CFLAGS="-fsanitize=memory\
-fsanitize-memory-track-origins"
(Additionally, llvm might have to be installed and clang might have to
be specified as the compiler - export CC=/usr/bin/clang)
then running:
tools/perf/perf record -o - ls / | tools/perf/perf --no-pager annotate\
-i - --stdio
Please see the cover letter for why false positive warnings may be
generated.
Signed-off-by: Numfor Mbiziwo-Tiapo <nums@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Drayton <mbd@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/20190724234500.253358-2-nums@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull perf/urgent fixes from Arnaldo Carvalho de Melo:
perf.data:
Alexey Budankov:
- Fix loading of compressed data split across adjacent records
Jiri Olsa:
- Fix buffer size setting for processing CPU topology perf.data header.
perf stat:
Jiri Olsa:
- Fix segfault for event group in repeat mode
Cong Wang:
- Always separate "stalled cycles per insn" line, it was being appended to
the "instructions" line.
perf script:
Andi Kleen:
- Fix --max-blocks man page description.
- Improve man page description of metrics.
- Fix off by one in brstackinsn IPC computation.
perf probe:
Arnaldo Carvalho de Melo:
- Avoid calling freeing routine multiple times for same pointer.
perf build:
- Do not use -Wshadow on gcc < 4.8, avoiding too strict warnings
treated as errors, breaking the build.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When perf_add_probe_events() we call cleanup_perf_probe_events() for the
pev pointer it receives, then, as part of handling this failure the main
'perf probe' goes on and calls cleanup_params() and that will again call
cleanup_perf_probe_events()for the same pointer, so just set nevents to
zero when handling the failure of perf_add_probe_events() to avoid the
double free.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-x8qgma4g813z96dvtw9w219q@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
So that, when perf_add_probe_events() fails, like in:
# perf probe icmp_rcv:64 "type=icmph->type"
Failed to find 'icmph' in this function.
Error: Failed to add events.
Segmentation fault (core dumped)
#
We don't segfault.
clear_perf_probe_event() was zeroing the whole pev, and since the switch
to zfree() for the members in the pev, that memset() was removed, which
left nargs with its original value, in the above case 1.
With the memset the same pev could be passed to clear_perf_probe_event()
multiple times, since all it would have would be zeroes, and free()
accepts zero, the loop would not happen and we would just memset it
again to zeroes.
Without it we got that segfault, so zero nargs to keep it like it was,
next cset will avoid calling clear_perf_probe_event() for the same pevs
in case of failure.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Fixes: d8f9da2404 ("perf tools: Use zfree() where applicable")
Link: https://lkml.kernel.org/n/tip-802f2jypnwqsvyavvivs8464@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fix decompression failure found during the loading of compressed trace
collected on larger scale systems (>48 cores).
The error happened due to lack of decompression space for a mmaped
buffer data chunk split across adjacent PERF_RECORD_COMPRESSED records.
$ perf report -i bt.16384.data --stats
failed to decompress (B): 63869 -> 0 : Destination buffer is too small
user stack dump failure
Can't parse sample, err = -14
0x2637e436 [0x4080]: failed to process type: 9
Error:
failed to process sample
$ perf test 71
71: Zstd perf.data compression/decompression : Ok
Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/4d839e1b-9c48-89c4-9702-a12217420611@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The "stalled cycles per insn" is appended to "instructions" when the CPU
has this hardware counter directly. We should always make it a separate
line, which also aligns to the output when we hit the "if (total &&
avg)" branch.
Before:
$ sudo perf stat --all-cpus --field-separator , --log-fd 1 -einstructions,cycles -- sleep 1
4565048704,,instructions,64114578096,100.00,1.34,insn per cycle,,
3396325133,,cycles,64146628546,100.00,,
After:
$ sudo ./tools/perf/perf stat --all-cpus --field-separator , --log-fd 1 -einstructions,cycles -- sleep 1
6721924,,instructions,24026790339,100.00,0.22,insn per cycle
,,,,,0.00,stalled cycles per insn
30939953,,cycles,24025512526,100.00,,
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/20190517221039.8975-1-xiyou.wangcong@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Numfor Mbiziwo-Tiapo reported segfault on stat of event group in repeat
mode:
# perf stat -e '{cycles,instructions}' -r 10 ls
It's caused by memory corruption due to not cleaned evsel's id array and
index, which needs to be rebuilt in every stat iteration. Currently the
ids index grows, while the array (which is also not freed) has the same
size.
Fixing this by releasing id array and zeroing ids index in
perf_evsel__close function.
We also need to keep the evsel_list alive for stat record (which is
disabled in repeat mode).
Reported-by: Numfor Mbiziwo-Tiapo <nums@google.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Drayton <mbd@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/20190715142121.GC6032@krava
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull perf tooling updates from Thomas Gleixner:
"A set of perf improvements and fixes:
perf db-export:
- Improvements in how COMM details are exported to databases for post
processing and use in the sql-viewer.py UI.
- Export switch events to the database.
BPF:
- Bump rlimit(MEMLOCK) for 'perf test bpf' and 'perf trace', just
like selftests/bpf/bpf_rlimit.h do, which makes errors due to
exhaustion of this limit, which are kinda cryptic (EPERM sometimes)
less frequent.
perf version:
- Fix segfault due to missing OPT_END(), noticed on PowerPC.
perf vendor events:
- Add JSON files for IBM s/390 machine type 8561.
perf cs-etm (ARM):
- Fix two cases of error returns not bing done properly: Invalid
ERR_PTR() use and loss of propagation error codes"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (28 commits)
perf version: Fix segfault due to missing OPT_END()
perf vendor events s390: Add JSON files for machine type 8561
perf cs-etm: Return errcode in cs_etm__process_auxtrace_info()
perf cs-etm: Remove errnoeous ERR_PTR() usage in cs_etm__process_auxtrace_info
perf scripts python: export-to-postgresql.py: Export switch events
perf scripts python: export-to-sqlite.py: Export switch events
perf db-export: Export switch events
perf db-export: Factor out db_export__threads()
perf script: Add scripting operation process_switch()
perf scripts python: exported-sql-viewer.py: Use new 'has_calls' column
perf scripts python: exported-sql-viewer.py: Remove redundant semi-colons
perf scripts python: export-to-postgresql.py: Add has_calls column to comms table
perf scripts python: export-to-sqlite.py: Add has_calls column to comms table
perf db-export: Also export thread's current comm
perf db-export: Factor out db_export__comm()
perf scripts python: export-to-postgresql.py: Export comm details
perf scripts python: export-to-sqlite.py: Export comm details
perf db-export: Export comm details
perf db-export: Fix a white space issue in db_export__sample()
perf db-export: Move export__comm_thread into db_export__sample()
...
Pull tracing updates from Steven Rostedt:
"The main changes in this release include:
- Add user space specific memory reading for kprobes
- Allow kprobes to be executed earlier in boot
The rest are mostly just various clean ups and small fixes"
* tag 'trace-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits)
tracing: Make trace_get_fields() global
tracing: Let filter_assign_type() detect FILTER_PTR_STRING
tracing: Pass type into tracing_generic_entry_update()
ftrace/selftest: Test if set_event/ftrace_pid exists before writing
ftrace/selftests: Return the skip code when tracing directory not configured in kernel
tracing/kprobe: Check registered state using kprobe
tracing/probe: Add trace_event_call accesses APIs
tracing/probe: Add probe event name and group name accesses APIs
tracing/probe: Add trace flag access APIs for trace_probe
tracing/probe: Add trace_event_file access APIs for trace_probe
tracing/probe: Add trace_event_call register API for trace_probe
tracing/probe: Add trace_probe init and free functions
tracing/uprobe: Set print format when parsing command
tracing/kprobe: Set print format right after parsed command
kprobes: Fix to init kprobes in subsys_initcall
tracepoint: Use struct_size() in kmalloc()
ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS
ftrace: Enable trampoline when rec count returns back to one
tracing/kprobe: Do not run kprobe boot tests if kprobe_event is on cmdline
tracing: Make a separate config for trace event self tests
...
Export switch events to a new table 'context_switches' and create a view
'context_switches_view'. The table and view will show automatically in
the exported-sql-viewer.py script.
If the table ends up empty, then it and the view are dropped.
Committer testing:
Use the exported-sql-viewer.py and look at "Tables" ->
"context_switches":
id machine_id time cpu thread_out_id comm_out_id thread_in_id comm_in_id flags
1 1 187836111885918 7 1 1 2 2 3
2 1 187836111889369 7 1 1 2 2 0
3 1 187836112464618 7 2 3 1 1 1
4 1 187836112465511 7 2 3 1 1 0
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20190710085810.1650-21-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
