mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-06 03:06:50 -04:00
3cd65616f6
The attempt at using BPF to copy syscall pointer arguments to show them
like strace does started with sys_{enter,exit}_SYSCALL_NAME tracepoints,
in tools/perf/examples/bpf/augmented_syscalls.c, but then achieving this
result using raw_syscalls:{enter,exit} and BPF tail calls was deemed
more flexible.
The 'perf trace' codebase was adapted to using it while trying to
continue supporting the old style per-syscall tracepoints, which at some
point became too unwieldly and now isn't working properly.
So lets scale back and concentrate on the augmented_raw_syscalls.c
model on the way to using BPF skeletons.
For the same reason remove the etcsnoop.c example, that used the
old style per-tp syscalls just for the 'open' and 'openat' syscalls,
looking at the pathnames starting with "/etc/", we should be able
to do this later using filters, after we move to BPF skels.
The augmented_raw_syscalls.c one continues to work, now with libbpf 1.0,
after Ian work on using the libbpf map style:
# perf trace -e ~acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.c,open* --max-events 4
0.000 ping/194815 openat(dfd: CWD, filename: "/etc/hosts", flags: RDONLY|CLOEXEC) = 5
20.225 systemd-oomd/972 openat(dfd: CWD, filename: "/proc/meminfo", flags: RDONLY|CLOEXEC) = 12
20.285 abrt-dump-jour/1371 openat(dfd: CWD, filename: "/var/log/journal/d6a97235307247e09f13f326fb607e3c/system.journal", flags: RDONLY|CLOEXEC|NONBLOCK) = 21
20.301 abrt-dump-jour/1370 openat(dfd: CWD, filename: "/var/log/journal/d6a97235307247e09f13f326fb607e3c/system.journal", flags: RDONLY|CLOEXEC|NONBLOCK) = 21
#
This is using this:
# cat ~/.perfconfig
[trace]
show_zeros = yes
show_duration = no
no_inherit = yes
args_alignment = 40
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.