Go to file
Arnaldo Carvalho de Melo 362222f877 perf trace: Initialize evsel_trace->fmt for syscalls:sys_enter_* tracepoints
From the syscall_fmts->arg entries for formatting strace-like syscalls.

This is when resolving the string "whence" on a filter expression for
the syscalls:sys_enter_lseek:

  Breakpoint 3, perf_evsel__syscall_arg_fmt (evsel=0xc91ed0, arg=0x7fffffff7cd0 "whence") at builtin-trace.c:3626
  3626	{
  (gdb) n
  3628		struct syscall_arg_fmt *fmt = __evsel__syscall_arg_fmt(evsel);
  (gdb) n
  3630		if (evsel->tp_format == NULL || fmt == NULL)
  (gdb) n
  3633		for (field = evsel->tp_format->format.fields; field; field = field->next, ++fmt)
  (gdb) n
  3634			if (strcmp(field->name, arg) == 0)
  (gdb) p field->name
  $3 = 0xc945e0 "__syscall_nr"
  (gdb) n
  3633		for (field = evsel->tp_format->format.fields; field; field = field->next, ++fmt)
  (gdb) p *fmt
  $4 = {scnprintf = 0x0, strtoul = 0x0, mask_val = 0x0, parm = 0x0, name = 0x0, nr_entries = 0, show_zero = false}
  (gdb) n
  3634			if (strcmp(field->name, arg) == 0)
  (gdb) p field->name
  $5 = 0xc94690 "fd"
  (gdb) n
  3633		for (field = evsel->tp_format->format.fields; field; field = field->next, ++fmt)
  (gdb) n
  3634			if (strcmp(field->name, arg) == 0)
  (gdb) n
  3633		for (field = evsel->tp_format->format.fields; field; field = field->next, ++fmt)
  (gdb) n
  3634			if (strcmp(field->name, arg) == 0)
  (gdb) p *fmt
  $9 = {scnprintf = 0x489be2 <syscall_arg__scnprintf_strarray>, strtoul = 0x0, mask_val = 0x0, parm = 0xa2da80 <strarray.whences>, name = 0x0,
    nr_entries = 0, show_zero = false}
  (gdb) p field->name
  $10 = 0xc947b0 "whence"
  (gdb) p fmt->parm
  $11 = (void *) 0xa2da80 <strarray.whences>
  (gdb) p *(struct strarray *)fmt->parm
  $12 = {offset = 0, nr_entries = 5, prefix = 0x724d37 "SEEK_", entries = 0xa2da40 <whences>}
  (gdb) p (struct strarray *)fmt->parm)->entries
  Junk after end of expression.
  (gdb) p ((struct strarray *)fmt->parm)->entries
  $13 = (const char **) 0xa2da40 <whences>
  (gdb) p ((struct strarray *)fmt->parm)->entries[0]
  $14 = 0x724d21 "SET"
  (gdb) p ((struct strarray *)fmt->parm)->entries[1]
  $15 = 0x724d25 "CUR"
  (gdb) p ((struct strarray *)fmt->parm)->entries[2]
  $16 = 0x724d29 "END"
  (gdb) p ((struct strarray *)fmt->parm)->entries[2]
  $17 = 0x724d29 "END"
  (gdb) p ((struct strarray *)fmt->parm)->entries[3]
  $18 = 0x724d2d "DATA"
  (gdb) p ((struct strarray *)fmt->parm)->entries[4]
  $19 = 0x724d32 "HOLE"
  (gdb)

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@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-lc8h9jgvbnboe0g7ic8tra1y@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-10-18 12:07:42 -03:00
arch USB fixes for 5.4-rc3 2019-10-12 15:37:12 -07:00
block blk-wbt: fix performance regression in wbt scale_up/scale_down 2019-10-06 09:26:41 -06:00
certs PKCS#7: Refactor verify_pkcs7_signature() 2019-08-05 18:40:18 -04:00
crypto Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
Documentation hwmon fixes for v5.4-rc3 2019-10-13 08:40:31 -07:00
drivers hwmon fixes for v5.4-rc3 2019-10-13 08:40:31 -07:00
fs A few tracing fixes: 2019-10-13 14:47:10 -07:00
include hwmon fixes for v5.4-rc3 2019-10-13 08:40:31 -07:00
init Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
ipc ipc/sem.c: convert to use built-in RCU list checking 2019-09-25 17:51:41 -07:00
kernel A few tracing fixes: 2019-10-13 14:47:10 -07:00
lib Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-10-12 14:46:14 -07:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm for-linus-20191010 2019-10-11 08:45:32 -07:00
net NFS Client Bugfixes for Linux 5.4-rc3 2019-10-11 14:28:59 -07:00
samples samples/bpf: fix build by setting HAVE_ATTR_TEST to zero 2019-10-07 12:22:18 -03:00
scripts A few tracing fixes: 2019-10-13 14:47:10 -07:00
security selinux/stable-5.4 PR 20191007 2019-10-08 10:51:37 -07:00
sound sound fixes for 5.4-rc1 2019-09-24 16:46:16 -07:00
tools perf trace: Initialize evsel_trace->fmt for syscalls:sys_enter_* tracepoints 2019-10-18 12:07:42 -03:00
usr kbuild: update compile-test header list for v5.4-rc2 2019-10-05 15:29:49 +09:00
virt KVM/arm fixes for 5.4, take #1 2019-10-03 12:08:50 +02:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Modules updates for v5.4 2019-09-22 10:34:46 -07:00
.mailmap Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2019-09-18 12:34:53 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS: Remove Simon as Renesas SoC Co-Maintainer 2019-10-10 08:12:51 -07:00
Kbuild kbuild: do not descend to ./Kbuild when cleaning 2019-08-21 21:03:58 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS perf/core improvements and fixes: 2019-10-15 07:19:55 +02:00
Makefile Linux 5.4-rc3 2019-10-13 16:37:36 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.