linux-stable/tools
Arnaldo Carvalho de Melo 64917f4df0 perf trace: Use heuristic when deciding if a syscall tracepoint "const char *" field is really a string
'perf trace' tries to find BPF progs associated with a syscall that have
a signature that is similar to syscalls without one to try and reuse,
so, for instance, the 'open' signature can be reused with many other
syscalls that have as its first arg a string.

It uses the tracefs events format file for finding a signature that can
be reused, but then comes the "write" syscall with its second argument
as a "const char *":

  # cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_write/format
  name: sys_enter_write
  ID: 746
  format:
  	field:unsigned short common_type;	offset:0;	size:2;	signed:0;
  	field:unsigned char common_flags;	offset:2;	size:1;	signed:0;
  	field:unsigned char common_preempt_count;	offset:3;	size:1;	signed:0;
  	field:int common_pid;	offset:4;	size:4;	signed:1;

  	field:int __syscall_nr;	offset:8;	size:4;	signed:1;
  	field:unsigned int fd;	offset:16;	size:8;	signed:0;
  	field:const char * buf;	offset:24;	size:8;	signed:0;
  	field:size_t count;	offset:32;	size:8;	signed:0;

  print fmt: "fd: 0x%08lx, buf: 0x%08lx, count: 0x%08lx", ((unsigned long)(REC->fd)), ((unsigned long)(REC->buf)), ((unsigned long)(REC->count))
  #

Which isn't a string (the man page for glibc has buf as "void *"), so we
have to use the name of the argument as an heuristic, to consider a
string just args that are "const char *" and that have in its name  the
"path", "file", etc substrings.

With that now it reuses:

  [root@quaco ~]# perf trace -v --max-events=1 |& grep Reus
  Reusing "open" BPF sys_enter augmenter for "stat"
  Reusing "open" BPF sys_enter augmenter for "lstat"
  Reusing "open" BPF sys_enter augmenter for "access"
  Reusing "connect" BPF sys_enter augmenter for "accept"
  Reusing "sendto" BPF sys_enter augmenter for "recvfrom"
  Reusing "connect" BPF sys_enter augmenter for "bind"
  Reusing "connect" BPF sys_enter augmenter for "getsockname"
  Reusing "connect" BPF sys_enter augmenter for "getpeername"
  Reusing "open" BPF sys_enter augmenter for "execve"
  Reusing "open" BPF sys_enter augmenter for "truncate"
  Reusing "open" BPF sys_enter augmenter for "chdir"
  Reusing "open" BPF sys_enter augmenter for "mkdir"
  Reusing "open" BPF sys_enter augmenter for "rmdir"
  Reusing "open" BPF sys_enter augmenter for "creat"
  Reusing "open" BPF sys_enter augmenter for "link"
  Reusing "open" BPF sys_enter augmenter for "unlink"
  Reusing "open" BPF sys_enter augmenter for "symlink"
  Reusing "open" BPF sys_enter augmenter for "readlink"
  Reusing "open" BPF sys_enter augmenter for "chmod"
  Reusing "open" BPF sys_enter augmenter for "chown"
  Reusing "open" BPF sys_enter augmenter for "lchown"
  Reusing "open" BPF sys_enter augmenter for "mknod"
  Reusing "open" BPF sys_enter augmenter for "statfs"
  Reusing "open" BPF sys_enter augmenter for "pivot_root"
  Reusing "open" BPF sys_enter augmenter for "chroot"
  Reusing "open" BPF sys_enter augmenter for "acct"
  Reusing "open" BPF sys_enter augmenter for "swapon"
  Reusing "open" BPF sys_enter augmenter for "swapoff"
  Reusing "open" BPF sys_enter augmenter for "delete_module"
  Reusing "open" BPF sys_enter augmenter for "setxattr"
  Reusing "open" BPF sys_enter augmenter for "lsetxattr"
  Reusing "openat" BPF sys_enter augmenter for "fsetxattr"
  Reusing "open" BPF sys_enter augmenter for "getxattr"
  Reusing "open" BPF sys_enter augmenter for "lgetxattr"
  Reusing "openat" BPF sys_enter augmenter for "fgetxattr"
  Reusing "open" BPF sys_enter augmenter for "listxattr"
  Reusing "open" BPF sys_enter augmenter for "llistxattr"
  Reusing "open" BPF sys_enter augmenter for "removexattr"
  Reusing "open" BPF sys_enter augmenter for "lremovexattr"
  Reusing "fsetxattr" BPF sys_enter augmenter for "fremovexattr"
  Reusing "open" BPF sys_enter augmenter for "mq_open"
  Reusing "open" BPF sys_enter augmenter for "mq_unlink"
  Reusing "fsetxattr" BPF sys_enter augmenter for "add_key"
  Reusing "fremovexattr" BPF sys_enter augmenter for "request_key"
  Reusing "fremovexattr" BPF sys_enter augmenter for "inotify_add_watch"
  Reusing "fremovexattr" BPF sys_enter augmenter for "mkdirat"
  Reusing "fremovexattr" BPF sys_enter augmenter for "mknodat"
  Reusing "fremovexattr" BPF sys_enter augmenter for "fchownat"
  Reusing "fremovexattr" BPF sys_enter augmenter for "futimesat"
  Reusing "fremovexattr" BPF sys_enter augmenter for "newfstatat"
  Reusing "fremovexattr" BPF sys_enter augmenter for "unlinkat"
  Reusing "fremovexattr" BPF sys_enter augmenter for "linkat"
  Reusing "open" BPF sys_enter augmenter for "symlinkat"
  Reusing "fremovexattr" BPF sys_enter augmenter for "readlinkat"
  Reusing "fremovexattr" BPF sys_enter augmenter for "fchmodat"
  Reusing "fremovexattr" BPF sys_enter augmenter for "faccessat"
  Reusing "fremovexattr" BPF sys_enter augmenter for "utimensat"
  Reusing "connect" BPF sys_enter augmenter for "accept4"
  Reusing "fremovexattr" BPF sys_enter augmenter for "name_to_handle_at"
  Reusing "fremovexattr" BPF sys_enter augmenter for "renameat2"
  Reusing "open" BPF sys_enter augmenter for "memfd_create"
  Reusing "fremovexattr" BPF sys_enter augmenter for "execveat"
  Reusing "fremovexattr" BPF sys_enter augmenter for "statx"
  [root@quaco ~]#

Reviewed-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/ZN5lrdeEdSMCn7hk@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2023-08-18 16:33:28 -03:00
..
accounting
arch perf tools fixes for v6.5: 3rd batch 2023-08-09 21:06:14 -07:00
bootconfig
bpf
build perf bpf: Remove support for embedding clang for compiling BPF events (-e foo.c) 2023-08-15 16:41:48 -03:00
certs
cgroup
counter
debugging
edid
firewire
firmware
gpio
hv vmbus_testing: fix wrong python syntax for integer value comparison 2023-07-23 23:19:30 +00:00
iio
include tools include UAPI: Sync the sound/asound.h copy with the kernel sources 2023-07-14 10:33:50 -03:00
io_uring
kvm/kvm_stat
laptop
leds
lib libperf: Implement riscv mmap support 2023-08-16 08:52:47 -03:00
memory-model
mm
net/ynl tools: ynl-gen: fix parse multi-attr enum attribute 2023-07-26 13:38:23 -07:00
objtool x86/srso: Add a Speculative RAS Overflow mitigation 2023-07-27 11:07:14 +02:00
pci
pcmcia
perf perf trace: Use heuristic when deciding if a syscall tracepoint "const char *" field is really a string 2023-08-18 16:33:28 -03:00
power platform-drivers-x86 for v6.5-1 2023-06-30 14:50:00 -07:00
rcu
scripts tools build: Add 3-component logical version comparators 2023-08-03 16:59:40 -03:00
spi
testing x86: 2023-08-07 10:18:20 -07:00
thermal
time
tracing rtla/timerlat_hist: Add timerlat user-space support 2023-06-13 16:41:14 -04:00
usb
verification
virtio tools/virtio: fix build break for aarch64 2023-06-27 10:47:08 -04:00
wmi
workqueue
Makefile