20f9781f49
23 Commits
| Author | SHA1 | Message | Date | |
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Arnaldo Carvalho de Melo
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602bce09fb |
perf augmented_raw_syscalls: Move reading filename to the loop
Almost there, next step is to copy more than one filename payload. Probably to read syscall arg structs, etc we'll need just a variation of this that will decide what to use, if probe_read_str() or plain probe_read for structs, i.e. fixed size. 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-uf6u0pld6xe4xuo16f04owlz@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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Arnaldo Carvalho de Melo
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deaf4da48a |
perf augmented_raw_syscalls: Change helper to consider just the augmented_filename part
So that we can use it for multiple args, baby steps not to step into the verifier toes. In the process make sure we handle -EFAULT from bpf_prog_read_str(), as this really is needed now that we'll handle more than one augmented argument, i.e. if there is failure, then we have the argument that fails have: (size = 0, err = -EFAULT, value = [] ) followed by the next, lets say that worked for a second pathname: (size = 4, err = 0, value = "/tmp" ) So we can skip the first while telling the user about the problem and then process the second. 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-deyvqi39um6gp6hux6jovos8@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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Arnaldo Carvalho de Melo
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0c95a7ff76 |
perf augmented_raw_syscalls: Move the probe_read_str to a separate function
One more step into copying multiple filenames to support syscalls like rename*. 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-xdqtjexdyp81oomm1rkzeifl@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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Arnaldo Carvalho de Melo
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4cae8675ea |
perf augmented_raw_syscalls: Tell which args are filenames and how many bytes to copy
Since we know what args are strings from reading the syscall descriptions in tracefs and also already mark such args to be beautified using the syscall_arg__scnprintf_filename() helper, all we need is to fill in this info in the 'syscalls' BPF map we were using to state which syscalls the user is interested in, i.e. the syscall filter. Right now just set that with PATH_MAX and unroll the syscall arg in the BPF program, as the verifier isn't liking something clang generates when unrolling the loop. This also makes the augmented_raw_syscalls.c program support all arches, since we removed that set of defines with the hard coded syscall numbers, all should be automatically set for all arches, with the syscall id mapping done correcly. Doing baby steps here, i.e. just the first string arg for a syscall is printed, syscalls with more than one, say, the various rename* syscalls, need further work, but lets get first something that the BPF verifier accepts before increasing the complexity To test it, something like: # perf trace -e string -e /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.c With: # cat ~/.perfconfig [llvm] dump-obj = true clang-opt = -g [trace] #add_events = /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.c show_zeros = yes show_duration = no no_inherit = yes show_timestamp = no show_arg_names = no args_alignment = 40 show_prefix = yes # That commented add_events line is needed for developing this augmented_raw_syscalls.c BPF program, as if we add it via the 'add_events' mechanism so as to shorten the 'perf trace' command lines, then we end up not setting up the -v option which precludes us having access to the bpf verifier log :-\ Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexei Starovoitov <ast@fb.com> Cc: Andrii Nakryiko <andriin@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Leo Yan <leo.yan@linaro.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Song Liu <songliubraving@fb.com> Cc: Yonghong Song <yhs@fb.com> Link: https://lkml.kernel.org/n/tip-dn863ya0cbsqycxuy0olvbt1@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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Arnaldo Carvalho de Melo
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693bd3949b |
perf trace: Beautify 'fspick' arguments
Use existing beautifiers for the first 2 args (dfd, path) and wire up
the recently introduced fspick flags table generator.
Now it should be possible to just use:
perf trace -e fspick
As root and see all move_mount syscalls with its args beautified, either
using the vfs_getname perf probe method or using the
augmented_raw_syscalls.c eBPF helper to get the pathnames, the other
args should work in all cases, i.e. all that is needed can be obtained
directly from the raw_syscalls:sys_enter tracepoint args.
# cat sys_fspick.c
#define _GNU_SOURCE /* See feature_test_macros(7) */
#include <unistd.h>
#include <sys/syscall.h> /* For SYS_xxx definitions */
#include <fcntl.h>
#define __NR_fspick 433
#define FSPICK_CLOEXEC 0x00000001
#define FSPICK_SYMLINK_NOFOLLOW 0x00000002
#define FSPICK_NO_AUTOMOUNT 0x00000004
#define FSPICK_EMPTY_PATH 0x00000008
static inline int sys_fspick(int fd, const char *path, int flags)
{
syscall(__NR_fspick, fd, path, flags);
}
int main(int argc, char *argv[])
{
int flags = 0, fd = 0;
open("/foo", 0);
sys_fspick(fd++, "/foo1", flags);
flags |= FSPICK_CLOEXEC;
sys_fspick(fd++, "/foo2", flags);
flags |= FSPICK_SYMLINK_NOFOLLOW;
sys_fspick(fd++, "/foo3", flags);
flags |= FSPICK_NO_AUTOMOUNT;
sys_fspick(fd++, "/foo4", flags);
flags |= FSPICK_EMPTY_PATH;
return sys_fspick(fd++, "/foo5", flags);
}
# perf trace -e fspick ./sys_fspick
LLVM: dumping /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o
fspick(0, "/foo1", 0) = -1 ENOENT (No such file or directory)
fspick(1, "/foo2", FSPICK_CLOEXEC) = -1 ENOENT (No such file or directory)
fspick(2, "/foo3", FSPICK_CLOEXEC|FSPICK_SYMLINK_NOFOLLOW) = -1 ENOENT (No such file or directory)
fspick(3, "/foo4", FSPICK_CLOEXEC|FSPICK_SYMLINK_NOFOLLOW|FSPICK_NO_AUTOMOUNT) = -1 ENOENT (No such file or directory)
fspick(4, "/foo5", FSPICK_CLOEXEC|FSPICK_SYMLINK_NOFOLLOW|FSPICK_NO_AUTOMOUNT|FSPICK_EMPTY_PATH) = -1 ENOENT (No such file or directory)
#
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
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-erau5xjtt8wvgnhvdbchstuk@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Arnaldo Carvalho de Melo
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566e30229e |
perf trace: Beautify 'move_mount' arguments
Use existing beautifiers for the first 4 args (to/from fds, pathnames)
and wire up the recently introduced move_mount flags table generator.
Now it should be possible to just use:
perf trace -e move_mount
As root and see all move_mount syscalls with its args beautified, except
for the filenames, that need work in the augmented_raw_syscalls.c eBPF
helper to pass more than one, see comment in the
augmented_raw_syscalls.c source code, the other args should work in all
cases, i.e. all that is needed can be obtained directly from the
raw_syscalls:sys_enter tracepoint args.
Running without the strace "skin" (.perfconfig setting output formatting
switches to look like strace output + BPF to collect strings, as we
still need to support collecting multiple string args for the same
syscall, like with move_mount):
# cat sys_move_mount.c
#define _GNU_SOURCE /* See feature_test_macros(7) */
#include <unistd.h>
#include <sys/syscall.h> /* For SYS_xxx definitions */
#define __NR_move_mount 429
#define MOVE_MOUNT_F_SYMLINKS 0x00000001 /* Follow symlinks on from path */
#define MOVE_MOUNT_F_AUTOMOUNTS 0x00000002 /* Follow automounts on from path */
#define MOVE_MOUNT_F_EMPTY_PATH 0x00000004 /* Empty from path permitted */
#define MOVE_MOUNT_T_SYMLINKS 0x00000010 /* Follow symlinks on to path */
#define MOVE_MOUNT_T_AUTOMOUNTS 0x00000020 /* Follow automounts on to path */
#define MOVE_MOUNT_T_EMPTY_PATH 0x00000040 /* Empty to path permitted */
static inline int sys_move_mount(int from_fd, const char *from_pathname,
int to_fd, const char *to_pathname,
int flags)
{
syscall(__NR_move_mount, from_fd, from_pathname, to_fd, to_pathname, flags);
}
int main(int argc, char *argv[])
{
int flags = 0, from_fd = 0, to_fd = 100;
sys_move_mount(from_fd++, "/foo", to_fd++, "bar", flags);
flags |= MOVE_MOUNT_F_SYMLINKS;
sys_move_mount(from_fd++, "/foo1", to_fd++, "bar1", flags);
flags |= MOVE_MOUNT_F_AUTOMOUNTS;
sys_move_mount(from_fd++, "/foo2", to_fd++, "bar2", flags);
flags |= MOVE_MOUNT_F_EMPTY_PATH;
sys_move_mount(from_fd++, "/foo3", to_fd++, "bar3", flags);
flags |= MOVE_MOUNT_T_SYMLINKS;
sys_move_mount(from_fd++, "/foo4", to_fd++, "bar4", flags);
flags |= MOVE_MOUNT_T_AUTOMOUNTS;
sys_move_mount(from_fd++, "/foo5", to_fd++, "bar5", flags);
flags |= MOVE_MOUNT_T_EMPTY_PATH;
return sys_move_mount(from_fd++, "/foo6", to_fd++, "bar6", flags);
}
# mv ~/.perfconfig ~/.perfconfig.OFF
# perf trace -e move_mount ./sys_move_mount
0.000 ( 0.009 ms): sys_move_mount/28971 move_mount(from_pathname: 0x402010, to_dfd: 100, to_pathname: 0x402015) = -1 ENOENT (No such file or directory)
0.011 ( 0.003 ms): sys_move_mount/28971 move_mount(from_dfd: 1, from_pathname: 0x40201e, to_dfd: 101, to_pathname: 0x402019, flags: F_SYMLINKS) = -1 ENOENT (No such file or directory)
0.016 ( 0.002 ms): sys_move_mount/28971 move_mount(from_dfd: 2, from_pathname: 0x402029, to_dfd: 102, to_pathname: 0x402024, flags: F_SYMLINKS|F_AUTOMOUNTS) = -1 ENOENT (No such file or directory)
0.020 ( 0.002 ms): sys_move_mount/28971 move_mount(from_dfd: 3, from_pathname: 0x402034, to_dfd: 103, to_pathname: 0x40202f, flags: F_SYMLINKS|F_AUTOMOUNTS|F_EMPTY_PATH) = -1 ENOENT (No such file or directory)
0.023 ( 0.002 ms): sys_move_mount/28971 move_mount(from_dfd: 4, from_pathname: 0x40203f, to_dfd: 104, to_pathname: 0x40203a, flags: F_SYMLINKS|F_AUTOMOUNTS|F_EMPTY_PATH|T_SYMLINKS) = -1 ENOENT (No such file or directory)
0.027 ( 0.002 ms): sys_move_mount/28971 move_mount(from_dfd: 5, from_pathname: 0x40204a, to_dfd: 105, to_pathname: 0x402045, flags: F_SYMLINKS|F_AUTOMOUNTS|F_EMPTY_PATH|T_SYMLINKS|T_AUTOMOUNTS) = -1 ENOENT (No such file or directory)
0.031 ( 0.017 ms): sys_move_mount/28971 move_mount(from_dfd: 6, from_pathname: 0x402055, to_dfd: 106, to_pathname: 0x402050, flags: F_SYMLINKS|F_AUTOMOUNTS|F_EMPTY_PATH|T_SYMLINKS|T_AUTOMOUNTS|T_EMPTY_PATH) = -1 ENOENT (No such file or directory)
#
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-83rim8g4k0s4gieieh5nnlck@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Arnaldo Carvalho de Melo
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8a70c6b162 |
perf augmented_raw_syscalls: Fix up comment
Cut'n'paste error, the second comment is about the syscalls that have as its second arg a string. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lkml.kernel.org/n/tip-zo5s6rloy42u41acsf6q3pvi@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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Arnaldo Carvalho de Melo
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59f3bd7802 |
perf augmented_raw_syscalls: Use a PERCPU_ARRAY map to copy more string bytes
The previous method, copying to the BPF stack limited us in how many
bytes we could copy from strings, use a PERCPU_ARRAY map like devised by
the sysdig guys[1] to copy more bytes:
Before:
# trace --no-inherit -e openat touch `python -c "print "$s" 'a' * 2000"`
touch: cannot touch 'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa': File name too long
openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib64/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/usr/lib/locale/locale-archive", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", O_CREAT|O_NOCTTY|O_NONBLOCK|O_WRONLY, S_IRUGO|S_IWUGO) = -1 ENAMETOOLONG (File name too long)
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) = -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)
<SNIP some openat calls>
#
After:
[root@quaco acme]# trace --no-inherit -e openat touch `python -c "print "$s" 'a' * 2000"`
<STRIP what is the same as in the 'before' part>
openat(AT_FDCWD, "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", O_CREAT|O_NOCTTY|O_NONBLOC) = -1 ENAMETOOLONG (File name too long)
<STRIP what is the same as in the 'before' part>
If we leave something like 'perf trace -e string' to trace all syscalls
with a string, and then do some 'perf top', to get some annotation for
the augmented_raw_syscalls.o BPF program we get:
│ → callq *ffffffffc45576d1 ▒
│ augmented_args->filename.size = probe_read_str(&augmented_args->filename.value, ▒
0.05 │ mov %eax,0x40(%r13)
Looking with pahole, expanding types, asking for hex offsets and sizes,
and use of BTF type information to see what is at that 0x40 offset from
%r13:
# pahole -F btf -C augmented_args_filename --expand_types --hex /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o
struct augmented_args_filename {
struct syscall_enter_args {
long long unsigned int common_tp_fields; /* 0 0x8 */
long int syscall_nr; /* 0x8 0x8 */
long unsigned int args[6]; /* 0x10 0x30 */
} args; /* 0 0x40 */
/* --- cacheline 1 boundary (64 bytes) --- */
struct augmented_filename {
unsigned int size; /* 0x40 0x4 */
int reserved; /* 0x44 0x4 */
char value[4096]; /* 0x48 0x1000 */
} filename; /* 0x40 0x1008 */
/* size: 4168, cachelines: 66, members: 2 */
/* last cacheline: 8 bytes */
};
#
Then looking if PATH_MAX leaves some signature in the tests:
│ if (augmented_args->filename.size < sizeof(augmented_args->filename.value)) { ▒
│ cmp $0xfff,%rdi
0xfff == 4095
sizeof(augmented_args->filename.value) == PATH_MAX == 4096
[1] https://sysdig.com/blog/the-art-of-writing-ebpf-programs-a-primer/
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andrii Nakryiko <andriin@fb.com>
Cc: Daniel Borkmann <borkmann@iogearbox.net>
Cc: Gianluca Borello <g.borello@gmail.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
cc: Martin Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Yonghong Song <yhs@fb.com>
Link: https://lkml.kernel.org/n/tip-76gce2d2ghzq537ubwhjkone@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Arnaldo Carvalho de Melo
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c52a82f779 |
perf augmented_raw_syscalls: Copy strings from all syscalls with 1st or 2nd string arg
Gets the augmented_raw_syscalls a bit more useful as-is, add a comment
stating that the intent is to have all this in a map populated by
userspace via the 'syscalls' BPF map, that right now has only a flag
stating if the syscall is filtered or not.
With it:
# grep -B1 augmented_raw ~/.perfconfig
[trace]
add_events = /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o
#
# perf trace -e string
weechat/6001 stat("/etc/localtime", 0x7ffe22c23d10) = 0
gnome-shell/1943 openat(AT_FDCWD, "/proc/self/stat", O_RDONLY) = 81
weechat/6001 stat("/etc/localtime", 0x7ffe22c23d10) = 0
gmain/2475 inotify_add_watch(20<anon_inode:inotify>, "/home/acme/.config/firewall", 16789454) = -1 ENOENT (No such file or directory)
gmain/2391 inotify_add_watch(3<anon_inode:inotify>, "", 16789454) = -1 ENOENT (No such file or directory)
gmain/2391 inotify_add_watch(3<anon_inode:inotify>, "/var/cache/app-info/yaml", 16789454) = -1 ENOENT (No such file or directory)
gmain/2391 inotify_add_watch(3<anon_inode:inotify>, "/var/lib/app-info/xmls", 16789454) = -1 ENOENT (No such file or directory)
gmain/2391 inotify_add_watch(3<anon_inode:inotify>, "/var/lib/app-info/yaml", 16789454) = -1 ENOENT (No such file or directory)
gmain/2391 inotify_add_watch(3<anon_inode:inotify>, "/usr/share/app-info/yaml", 16789454) = -1 ENOENT (No such file or directory)
gmain/2391 inotify_add_watch(3<anon_inode:inotify>, "/usr/local/share/app-info/xmls", 16789454) = -1 ENOENT (No such file or directory)
gmain/2391 inotify_add_watch(3<anon_inode:inotify>, "/usr/local/share/app-info/yaml", 16789454) = -1 ENOENT (No such file or directory)
gmain/2391 inotify_add_watch(3<anon_inode:inotify>, "/home/acme/.local/share/app-info/yaml", 16789454) = -1 ENOENT (No such file or directory)
gmain/1121 inotify_add_watch(12<anon_inode:inotify>, "/etc/NetworkManager/VPN", 16789454) = -1 ENOENT (No such file or directory)
weechat/6001 stat("/etc/localtime", 0x7ffe22c23d10) = 0
gmain/2050 inotify_add_watch(8<anon_inode:inotify>, "/home/acme/~", 16789454) = -1 ENOENT (No such file or directory)
gmain/2521 inotify_add_watch(6<anon_inode:inotify>, "/var/lib/fwupd/remotes.d/lvfs-testing", 16789454) = -1 ENOENT (No such file or directory)
weechat/6001 stat("/etc/localtime", 0x7ffe22c23d10) = 0
DOM Worker/22714 ... [continued]: openat()) = 257
FS Broker 3982/3990 openat(AT_FDCWD, "/dev/urandom", O_RDONLY|O_CLOEXEC|O_NOCTTY) = 187
DOMCacheThread/16652 mkdir("/home/acme/.mozilla/firefox/ina67tev.default/storage/default/https+++web.whatsapp.com/cache/morgue/192", S_IRUGO|S_IXUGO|S_IWUSR) = -1 EEXIST (File exists)
^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>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-a1hxffoy8t43e0wq6bzhp23u@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Arnaldo Carvalho de Melo
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56d8175a4d |
perf augmented_raw_syscalls: Use bpf_map()
To make the code more compact and also paving the way to have the BTF annotation to be done transparently. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com> Cc: Martin KaFai Lau <kafai@fb.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Cc: Yonghong Song <yhs@fb.com> Link: https://lkml.kernel.org/n/tip-pjlf38sv3i1hbn5vzkr4y3ol@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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Arnaldo Carvalho de Melo
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5620196951 |
perf: Make perf_event_output() propagate the output() return
For the original mode of operation it isn't needed, since we report back errors via PERF_RECORD_LOST records in the ring buffer, but for use in bpf_perf_event_output() it is convenient to return the errors, basically -ENOSPC. Currently bpf_perf_event_output() returns an error indication, the last thing it does, which is to push it to the ring buffer is that can fail and if so, this failure won't be reported back to its users, fix it. Reported-by: Jamal Hadi Salim <jhs@mojatatu.com> Tested-by: Jamal Hadi Salim <jhs@mojatatu.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lkml.kernel.org/r/20190118150938.GN5823@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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Arnaldo Carvalho de Melo
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c48ee107bb |
perf augmented_raw_syscalls: Copy 'access' arg as well
This will all come from userspace, but to test the changes to make 'perf trace' output similar to strace's, do this one more now manually. To update the precompiled augmented_raw_syscalls.o binary I just run: # perf record -e ~acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.c sleep 1 LLVM: dumping /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.022 MB perf.data ] # Because to have augmented_raw_syscalls to be always used and a fast startup and remove the need to have the llvm toolchain installed, I'm using: # perf config | grep add_events trace.add_events=/home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o # So when doing changes to augmented_raw_syscals.c one needs to rebuild the .o file. This will be done automagically later, i.e. have a 'make' behaviour of recompiling when the .c gets changed. 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> Cc: Wang Nan <wangnan0@huawei.com> Link: https://lkml.kernel.org/n/tip-lw3i2atyq8549fpqwmszn3qp@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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Arnaldo Carvalho de Melo
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4623ce405d |
perf augmented_raw_syscalls: Do not include stdio.h
We're not using that puts() thing, and thus we don't need to define the __bpf_stdout__ map, reducing the setup time. 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> Cc: Wang Nan <wangnan0@huawei.com> Link: https://lkml.kernel.org/n/tip-3452xgatncpil7v22minkwbo@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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Arnaldo Carvalho de Melo
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27f2992e7b |
perf augmented_syscalls: Switch to using a struct for the syscalls map values
We'll start adding more perf-syscall stuff, so lets do this prep step so
that the next ones are just about adding more fields.
Run it with the .c file once to cache the .o file:
# trace --filter-pids 2834,2199 -e openat,augmented_raw_syscalls.c
LLVM: dumping augmented_raw_syscalls.o
0.000 ( 0.021 ms): tmux: server/4952 openat(dfd: CWD, filename: /proc/5691/cmdline ) = 11
349.807 ( 0.040 ms): DNS Res~er #39/11082 openat(dfd: CWD, filename: /etc/hosts, flags: CLOEXEC ) = 44
4988.759 ( 0.052 ms): gsd-color/2431 openat(dfd: CWD, filename: /etc/localtime ) = 18
4988.976 ( 0.029 ms): gsd-color/2431 openat(dfd: CWD, filename: /etc/localtime ) = 18
^C[root@quaco bpf]#
From now on, we can use just the newly built .o file, skipping the
compilation step for a faster startup:
# trace --filter-pids 2834,2199 -e openat,augmented_raw_syscalls.o
0.000 ( 0.046 ms): DNS Res~er #39/11088 openat(dfd: CWD, filename: /etc/hosts, flags: CLOEXEC ) = 44
1946.408 ( 0.190 ms): systemd/1 openat(dfd: CWD, filename: /proc/1071/cgroup, flags: CLOEXEC ) = 20
1946.792 ( 0.215 ms): systemd/1 openat(dfd: CWD, filename: /proc/954/cgroup, flags: CLOEXEC ) = 20
^C#
Now on to do the same in the builtin-trace.c side of things.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-k8mwu04l8es29rje5loq9vg7@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Arnaldo Carvalho de Melo
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b27b38ed94 |
perf trace: Implement syscall filtering in augmented_syscalls
Just another map, this time an BPF_MAP_TYPE_ARRAY, stating with
one bool per syscall, stating if it should be filtered or not.
So, with a pre-built augmented_raw_syscalls.o file, we use:
# perf trace -e open*,augmented_raw_syscalls.o
0.000 ( 0.016 ms): DNS Res~er #37/29652 openat(dfd: CWD, filename: /etc/hosts, flags: CLOEXEC ) = 138
187.039 ( 0.048 ms): gsd-housekeepi/2436 openat(dfd: CWD, filename: /etc/fstab, flags: CLOEXEC ) = 11
187.348 ( 0.041 ms): gsd-housekeepi/2436 openat(dfd: CWD, filename: /proc/self/mountinfo, flags: CLOEXEC ) = 11
188.793 ( 0.036 ms): gsd-housekeepi/2436 openat(dfd: CWD, filename: /proc/self/mountinfo, flags: CLOEXEC ) = 11
189.803 ( 0.029 ms): gsd-housekeepi/2436 openat(dfd: CWD, filename: /proc/self/mountinfo, flags: CLOEXEC ) = 11
190.774 ( 0.027 ms): gsd-housekeepi/2436 openat(dfd: CWD, filename: /proc/self/mountinfo, flags: CLOEXEC ) = 11
284.620 ( 0.149 ms): DataStorage/3076 openat(dfd: CWD, filename: /home/acme/.mozilla/firefox/ina67tev.default/SiteSecurityServiceState.txt, flags: CREAT|TRUNC|WRONLY, mode: IRUGO|IWUSR|IWGRP) = 167
^C#
What is it that this gsd-housekeeping thingy needs to open
/proc/self/mountinfo four times periodically? :-)
This map will be extended to tell per-syscall parameters, i.e. how many
bytes to copy per arg, using the function signature to get the types and
then the size of those types, via BTF.
Cc: Adrian Hunter <adrian.hunter@intel.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-cy222g9ucvnym3raqvxp0hpg@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Arnaldo Carvalho de Melo
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4aa792de0b |
Revert "perf augmented_syscalls: Drop 'write', 'poll' for testing without self pid filter"
Now that we have the "filtered_pids" logic in place, no need to do this rough filter to avoid the feedback loop from 'perf trace's own syscalls, revert it. This reverts commit 7ed71f124284359676b6496ae7db724fee9da753. 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-88vh02cnkam0vv5f9vp02o3h@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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Arnaldo Carvalho de Melo
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e312747b49 |
perf augmented_syscalls: Remove example hardcoded set of filtered pids
Now that 'perf trace' fills in that "filtered_pids" BPF map, remove the
set of filtered pids used as an example to test that feature.
That feature works like this:
Starting a system wide 'strace' like 'perf trace' augmented session we
noticed that lots of events take place for a pid, which ends up being
the feedback loop of perf trace's syscalls being processed by the
'gnome-terminal' process:
# perf trace -e tools/perf/examples/bpf/augmented_raw_syscalls.c
0.391 ( 0.002 ms): gnome-terminal/2469 read(fd: 17</dev/ptmx>, buf: 0x564b79f750bc, count: 8176) = 453
0.394 ( 0.001 ms): gnome-terminal/2469 read(fd: 17</dev/ptmx>, buf: 0x564b79f75280, count: 7724) = -1 EAGAIN Resource temporarily unavailable
0.438 ( 0.001 ms): gnome-terminal/2469 read(fd: 4<anon_inode:[eventfd]>, buf: 0x7fffc696aeb0, count: 16) = 8
0.519 ( 0.001 ms): gnome-terminal/2469 read(fd: 17</dev/ptmx>, buf: 0x564b79f75280, count: 7724) = 114
0.522 ( 0.001 ms): gnome-terminal/2469 read(fd: 17</dev/ptmx>, buf: 0x564b79f752f1, count: 7611) = -1 EAGAIN Resource temporarily unavailable
^C
So we can use --filter-pids to get rid of that one, and in this case what is
being used to implement that functionality is that "filtered_pids" BPF map that
the tools/perf/examples/bpf/augmented_raw_syscalls.c created and that 'perf trace'
bpf loader noticed and created a "struct bpf_map" associated that then got populated
by 'perf trace':
# perf trace --filter-pids 2469 -e tools/perf/examples/bpf/augmented_raw_syscalls.c
0.020 ( 0.002 ms): gnome-shell/1663 epoll_pwait(epfd: 12<anon_inode:[eventpoll]>, events: 0x7ffd8f3ef960, maxevents: 32, sigsetsize: 8) = 1
0.025 ( 0.002 ms): gnome-shell/1663 read(fd: 24</dev/input/event4>, buf: 0x560c01bb8240, count: 8112) = 48
0.029 ( 0.001 ms): gnome-shell/1663 read(fd: 24</dev/input/event4>, buf: 0x560c01bb8258, count: 8088) = -1 EAGAIN Resource temporarily unavailable
0.032 ( 0.001 ms): gnome-shell/1663 read(fd: 24</dev/input/event4>, buf: 0x560c01bb8240, count: 8112) = -1 EAGAIN Resource temporarily unavailable
0.040 ( 0.003 ms): gnome-shell/1663 recvmsg(fd: 46<socket:[35893]>, msg: 0x7ffd8f3ef950) = -1 EAGAIN Resource temporarily unavailable
21.529 ( 0.002 ms): gnome-shell/1663 epoll_pwait(epfd: 5<anon_inode:[eventpoll]>, events: 0x7ffd8f3ef960, maxevents: 32, sigsetsize: 8) = 1
21.533 ( 0.004 ms): gnome-shell/1663 recvmsg(fd: 82<socket:[42826]>, msg: 0x7ffd8f3ef7b0, flags: DONTWAIT|CMSG_CLOEXEC) = 236
21.581 ( 0.006 ms): gnome-shell/1663 ioctl(fd: 8</dev/dri/card0>, cmd: DRM_I915_GEM_BUSY, arg: 0x7ffd8f3ef060) = 0
21.605 ( 0.020 ms): gnome-shell/1663 ioctl(fd: 8</dev/dri/card0>, cmd: DRM_I915_GEM_CREATE, arg: 0x7ffd8f3eeea0) = 0
21.626 ( 0.119 ms): gnome-shell/1663 ioctl(fd: 8</dev/dri/card0>, cmd: DRM_I915_GEM_SET_DOMAIN, arg: 0x7ffd8f3eee94) = 0
21.746 ( 0.081 ms): gnome-shell/1663 ioctl(fd: 8</dev/dri/card0>, cmd: DRM_I915_GEM_PWRITE, arg: 0x7ffd8f3eeea0) = 0
^C
Oops, yet another gnome process that is involved with the output that
'perf trace' generates, lets filter that out too:
# perf trace --filter-pids 2469,1663 -e tools/perf/examples/bpf/augmented_raw_syscalls.c
? ( ): wpa_supplicant/1366 ... [continued]: select()) = 0 Timeout
0.006 ( 0.002 ms): wpa_supplicant/1366 clock_gettime(which_clock: BOOTTIME, tp: 0x7fffe5b1e430) = 0
0.011 ( 0.001 ms): wpa_supplicant/1366 clock_gettime(which_clock: BOOTTIME, tp: 0x7fffe5b1e3e0) = 0
0.014 ( 0.001 ms): wpa_supplicant/1366 clock_gettime(which_clock: BOOTTIME, tp: 0x7fffe5b1e430) = 0
? ( ): gmain/1791 ... [continued]: poll()) = 0 Timeout
0.017 ( ): wpa_supplicant/1366 select(n: 6, inp: 0x55646fed3ad0, outp: 0x55646fed3b60, exp: 0x55646fed3bf0, tvp: 0x7fffe5b1e4a0) ...
157.879 ( 0.019 ms): gmain/1791 inotify_add_watch(fd: 8<anon_inode:inotify>, pathname: , mask: 16789454) = -1 ENOENT No such file or directory
? ( ): cupsd/1001 ... [continued]: epoll_pwait()) = 0
? ( ): gsd-color/1908 ... [continued]: poll()) = 0 Timeout
499.615 ( ): cupsd/1001 epoll_pwait(epfd: 4<anon_inode:[eventpoll]>, events: 0x557a21166500, maxevents: 4096, timeout: 1000, sigsetsize: 8) ...
586.593 ( 0.004 ms): gsd-color/1908 recvmsg(fd: 3<socket:[38074]>, msg: 0x7ffdef34e800) = -1 EAGAIN Resource temporarily unavailable
? ( ): fwupd/2230 ... [continued]: poll()) = 0 Timeout
? ( ): rtkit-daemon/906 ... [continued]: poll()) = 0 Timeout
? ( ): rtkit-daemon/907 ... [continued]: poll()) = 1
724.603 ( 0.007 ms): rtkit-daemon/907 read(fd: 6<anon_inode:[eventfd]>, buf: 0x7f05ff768d08, count: 8) = 8
? ( ): ssh/5461 ... [continued]: select()) = 1
810.431 ( 0.002 ms): ssh/5461 clock_gettime(which_clock: BOOTTIME, tp: 0x7ffd7f39f870) = 0
^C
Several syscall exit events for syscalls in flight when 'perf trace' started, etc. Saner :-)
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-c3tu5yg204p5mvr9kvwew07n@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Arnaldo Carvalho de Melo
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ed9a77ba77 |
perf augmented_syscalls: Use pid_filter
Just to test filtering a bunch of pids, now its time to go and get that hooked up in 'perf trace', right after we load the bpf program, if we find a "pids_filtered" map defined, we'll populate it with the filtered pids. 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-1i9s27wqqdhafk3fappow84x@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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Arnaldo Carvalho de Melo
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77ecb64050 |
perf augmented_syscalls: Drop 'write', 'poll' for testing without self pid filter
When testing system wide tracing without filtering the syscalls called by 'perf trace' itself we get into a feedback loop, drop for now those two syscalls, that are the ones that 'perf trace' does in its loop for writing the syscalls it intercepts, to help with testing till we get that filtering in place. 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-rkbu536af66dbsfx51sr8yof@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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Arnaldo Carvalho de Melo
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66067538e0 |
perf augmented_syscalls: Remove needless linux/socket.h include
Leftover from when we started augmented_raw_syscalls.c from
tools/perf/examples/bpf/augmented_syscalls.
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>
Fixes: e58a0322dbac ("perf examples bpf: Start augmenting raw_syscalls:sys_{start,exit}")
Link: https://lkml.kernel.org/n/tip-pmts9ls2skh8n3zisb4txudd@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Arnaldo Carvalho de Melo
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55f127b431 |
perf augmented_syscalls: Filter on a hard coded pid
Just to show where we'll hook pid based filters, and what we use to obtain the current pid, using a BPF getpid() equivalent. Now we need to remove that hardcoded PID with a BPF hash map, so that we start by filtering 'perf trace's own PID, implement the --filter-pid functionality, etc. 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-oshrcgcekiyhd0whwisxfvtv@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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Arnaldo Carvalho de Melo
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79ef68c7e1 |
perf augmented_syscalls: Start collecting pathnames in the BPF program
This is the start of having the raw_syscalls:sys_enter BPF handler collecting pointer arguments, namely pathnames, and with two syscalls that have that pointer in different arguments, "open" as it as its first argument, "openat" as the second. With this in place the existing beautifiers in 'perf trace' works, those args are shown instead of just the pointer that comes with the syscalls tracepoints. This also serves to show and document pitfalls in the process of using just that place in the kernel (raw_syscalls:sys_enter) plus tables provided by userspace to collect syscall pointer arguments. One is the need to use a barrier, as suggested by Edward, to avoid clang optimizations that make the kernel BPF verifier to refuse loading our pointer contents collector. The end result should be a generic eBPF program that works in all architectures, with the differences amongst archs resolved by the userspace component, 'perf trace', that should get all its tables created automatically from the kernel components where they are defined, via string table constructors for things not expressed in BTF/DWARF (enums, structs, etc), and otherwise using those observability files (BTF). Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David Ahern <dsahern@gmail.com> Cc: Edward Cree <ecree@solarflare.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Martin KaFai Lau <kafai@fb.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Cc: Yonghong Song <yhs@fb.com> Link: https://lkml.kernel.org/n/tip-37dz54pmotgpnwg9tb6zuk9j@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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Arnaldo Carvalho de Melo
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febf8a3712 |
perf examples bpf: Start augmenting raw_syscalls:sys_{start,exit}
The previous approach of attaching to each syscall showed how it is
possible to augment tracepoints and use that augmentation, pointer
payloads, in the existing beautifiers in 'perf trace', but for a more
general solution we now will try to augment the main
raw_syscalls:sys_{enter,exit} syscalls, and then pass instructions in
maps so that it knows which syscalls and which pointer contents, and how
many bytes for each of the arguments should be copied.
Start with just the bare minimum to collect what is provided by those
two tracepoints via the __augmented_syscalls__ map + bpf-output perf
event, which results in perf trace showing them without connecting
enter+exit:
# perf trace -e tools/perf/examples/bpf/augmented_raw_syscalls.c sleep 1
0.000 sleep/11563 raw_syscalls:sys_exit:NR 59 = 0
0.019 ( ): sleep/11563 brk() ...
0.021 sleep/11563 raw_syscalls:sys_exit:NR 12 = 94682642325504
0.033 ( ): sleep/11563 access(filename:, mode: R) ...
0.037 sleep/11563 raw_syscalls:sys_exit:NR 21 = -2
0.041 ( ): sleep/11563 openat(dfd: CWD, filename: , flags: CLOEXEC) ...
0.044 sleep/11563 raw_syscalls:sys_exit:NR 257 = 3
0.045 ( ): sleep/11563 fstat(fd: 3, statbuf: 0x7ffdbf7119b0) ...
0.046 sleep/11563 raw_syscalls:sys_exit:NR 5 = 0
0.047 ( ): sleep/11563 mmap(len: 103334, prot: READ, flags: PRIVATE, fd: 3) ...
0.049 sleep/11563 raw_syscalls:sys_exit:NR 9 = 140196285493248
0.050 ( ): sleep/11563 close(fd: 3) ...
0.051 sleep/11563 raw_syscalls:sys_exit:NR 3 = 0
0.059 ( ): sleep/11563 openat(dfd: CWD, filename: , flags: CLOEXEC) ...
0.062 sleep/11563 raw_syscalls:sys_exit:NR 257 = 3
0.063 ( ): sleep/11563 read(fd: 3, buf: 0x7ffdbf711b78, count: 832) ...
0.065 sleep/11563 raw_syscalls:sys_exit:NR 0 = 832
0.066 ( ): sleep/11563 fstat(fd: 3, statbuf: 0x7ffdbf711a10) ...
0.067 sleep/11563 raw_syscalls:sys_exit:NR 5 = 0
0.068 ( ): sleep/11563 mmap(len: 8192, prot: READ|WRITE, flags: PRIVATE|ANONYMOUS) ...
0.070 sleep/11563 raw_syscalls:sys_exit:NR 9 = 140196285485056
0.073 ( ): sleep/11563 mmap(len: 3889792, prot: EXEC|READ, flags: PRIVATE|DENYWRITE, fd: 3) ...
0.076 sleep/11563 raw_syscalls:sys_exit:NR 9 = 140196279463936
0.077 ( ): sleep/11563 mprotect(start: 0x7f81fd8a8000, len: 2093056) ...
0.083 sleep/11563 raw_syscalls:sys_exit:NR 10 = 0
0.084 ( ): sleep/11563 mmap(addr: 0x7f81fdaa7000, len: 24576, prot: READ|WRITE, flags: PRIVATE|FIXED|DENYWRITE, fd: 3, off: 1753088) ...
0.088 sleep/11563 raw_syscalls:sys_exit:NR 9 = 140196283314176
0.091 ( ): sleep/11563 mmap(addr: 0x7f81fdaad000, len: 14976, prot: READ|WRITE, flags: PRIVATE|FIXED|ANONYMOUS) ...
0.093 sleep/11563 raw_syscalls:sys_exit:NR 9 = 140196283338752
0.097 ( ): sleep/11563 close(fd: 3) ...
0.098 sleep/11563 raw_syscalls:sys_exit:NR 3 = 0
0.107 ( ): sleep/11563 arch_prctl(option: 4098, arg2: 140196285490432) ...
0.108 sleep/11563 raw_syscalls:sys_exit:NR 158 = 0
0.143 ( ): sleep/11563 mprotect(start: 0x7f81fdaa7000, len: 16384, prot: READ) ...
0.146 sleep/11563 raw_syscalls:sys_exit:NR 10 = 0
0.157 ( ): sleep/11563 mprotect(start: 0x561d037e7000, len: 4096, prot: READ) ...
0.160 sleep/11563 raw_syscalls:sys_exit:NR 10 = 0
0.163 ( ): sleep/11563 mprotect(start: 0x7f81fdcd5000, len: 4096, prot: READ) ...
0.165 sleep/11563 raw_syscalls:sys_exit:NR 10 = 0
0.166 ( ): sleep/11563 munmap(addr: 0x7f81fdcbb000, len: 103334) ...
0.174 sleep/11563 raw_syscalls:sys_exit:NR 11 = 0
0.216 ( ): sleep/11563 brk() ...
0.217 sleep/11563 raw_syscalls:sys_exit:NR 12 = 94682642325504
0.217 ( ): sleep/11563 brk(brk: 0x561d05453000) ...
0.219 sleep/11563 raw_syscalls:sys_exit:NR 12 = 94682642460672
0.220 ( ): sleep/11563 brk() ...
0.221 sleep/11563 raw_syscalls:sys_exit:NR 12 = 94682642460672
0.224 ( ): sleep/11563 open(filename: , flags: CLOEXEC) ...
0.228 sleep/11563 raw_syscalls:sys_exit:NR 2 = 3
0.229 ( ): sleep/11563 fstat(fd: 3, statbuf: 0x7f81fdaacaa0) ...
0.230 sleep/11563 raw_syscalls:sys_exit:NR 5 = 0
0.231 ( ): sleep/11563 mmap(len: 113045344, prot: READ, flags: PRIVATE, fd: 3) ...
0.234 sleep/11563 raw_syscalls:sys_exit:NR 9 = 140196166418432
0.237 ( ): sleep/11563 close(fd: 3) ...
0.238 sleep/11563 raw_syscalls:sys_exit:NR 3 = 0
0.262 ( ): sleep/11563 nanosleep(rqtp: 0x7ffdbf7126f0) ...
1000.399 sleep/11563 raw_syscalls:sys_exit:NR 35 = 0
1000.440 ( ): sleep/11563 close(fd: 1) ...
1000.447 sleep/11563 raw_syscalls:sys_exit:NR 3 = 0
1000.454 ( ): sleep/11563 close(fd: 2) ...
1000.468 ( ): sleep/11563 exit_group( )
#
In the next csets we'll connect those events to the existing enter/exit
raw_syscalls handlers in 'perf trace', just like we did with the
syscalls:sys_{enter,exit}_* tracepoints.
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-5nl8l4hx1tl9pqdx65nkp6pw@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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