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Gabriel F. T. Gomes 79ced5a893 Add helper script for glibc debugging
This patch adds a new make rule that generates a helper script for
debugging glibc test cases.  The new script, debugglibc.sh, is similar
to testrun.sh, in the sense that it allows the execution of the
specified test case, however, it opens the test case in GDB, setting the
library path the same way that testrun.sh does.  The commands are based
on the instructions on the wiki for glibc debugging [1,2].

By default, the script tells GDB to load the test case for symbol
information, so that, when a breakpoint is hit, the call stack is
displayed correctly (instead of printing lots of '??'s).  For instance,
after running 'make' and 'make check', one could do the following:

  $ ./debugglibc.sh nptl/tst-exec1 -b pthread_join

  Reading symbols from /home/gabriel/build/powerpc64le/glibc//elf/ld.so...done.
  Breakpoint 1 at 0x1444
  add symbol table from file "nptl/tst-exec1"
  [Thread debugging using libthread_db enabled]
  Using host libthread_db library "/home/gabriel/build/powerpc64le/glibc//nptl_db/libthread_db.so.1".

  Breakpoint 1, 0x00007ffff7fb1444 in _dl_start_user () from /home/gabriel/build/powerpc64le/glibc/elf/ld.so
  Breakpoint 2 at 0x7ffff7f49d48: file pthread_join.c, line 23.

Notice that the script will always start GDB with the program running
and halted at _dl_start_user.  So, in order to reach the actual
breakpoint of interest, one should hit 'c', not 'r':

  >>> c
  Continuing.
  [New Thread 0x7ffff7d1f180 (LWP 76443)]
  [Switching to Thread 0x7ffff7d1f180 (LWP 76443)]

  Thread 2 "ld.so" hit Breakpoint 2, __pthread_join (threadid=140737354087616, thread_return=0x0) at pthread_join.c:24
  24        return __pthread_timedjoin_ex (threadid, thread_return, NULL, true);

Then inspect the call stack with 'bt', as usual, and see symbols from
both the test case and from the libraries themselves:

  >>> bt
  #0  __pthread_join (threadid=140737354087616, thread_return=0x0) at pthread_join.c:24
  #1  0x0000000010001f4c in tf (arg=<optimized out>) at tst-exec1.c:37
  #2  0x00007ffff7f487e8 in start_thread (arg=0x7ffff7510000) at pthread_create.c:479
  #3  0x00007ffff7e523a8 in clone () at ../sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S:82

Tested for powerpc64le and x86_64.

[1] https://sourceware.org/glibc/wiki/Debugging/Loader_Debugging
[2] https://sourceware.org/glibc/wiki/Testing/Builds#Required_gdb_setup

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Dmitry V. Levin <ldv@altlinux.org>
Reviewed-by: Joseph Myers <joseph@codesourcery.com>
Reviewed-by: Andreas Schwab <schwab@suse.de>
2019-09-30 08:37:18 -03:00
argp Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
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benchtests Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
bits Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
catgets Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
ChangeLog.old Correct the spelling of more contributors 2019-08-29 02:50:04 -07:00
conform Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
crypt Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
csu Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
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debug Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
dirent Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
dlfcn Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
elf Add UNSUPPORTED check in elf/tst-pldd. 2019-09-18 12:42:39 +02:00
gmon Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
gnulib Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
grp Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
gshadow Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
hesiod Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
htl Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
hurd Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
iconv Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
iconvdata Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
include y2038: Introduce struct __timespec64 - new internal glibc type 2019-09-26 23:32:27 +02:00
inet inet/net-internal.h: Fix uninitalised clntudp_call() variable 2019-09-24 21:55:36 +01:00
intl Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
io Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
libio Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
locale Regenerate charmap-kw.h, locfile-kw.h 2019-09-09 14:16:40 -07:00
localedata Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
login Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
mach Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
malloc Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
manual Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
math Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
mathvec Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
misc Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
nis Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
nptl Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
nptl_db Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
nscd Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
nss Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
po Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
posix Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
pwd Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
resolv Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
resource Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
rt Set the expects flags to clock_nanosleep 2019-09-25 16:28:45 -07:00
scripts auto-changelog: Remove latin1 from codecs 2019-09-26 12:04:26 -07:00
setjmp Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
shadow Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
signal Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
socket Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
soft-fp Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
stdio-common Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
stdlib Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
string Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
sunrpc Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
support Fix building support_ptrace.c on i686-gnu. 2019-09-19 12:26:18 +02:00
sysdeps [powerpc] Rename fesetenv_mode to fesetenv_control 2019-09-27 11:03:25 -05:00
sysvipc Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
termios Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
time Set the expects flags to clock_nanosleep 2019-09-25 16:28:45 -07:00
timezone Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
wcsmbs Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
wctype Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
.gitattributes
.gitignore
abi-tags
aclocal.m4
ChangeLog [powerpc] Rename fesetenv_mode to fesetenv_control 2019-09-27 11:03:25 -05:00
config.h.in S390: Add configure check to detect support for arch13. 2019-03-22 11:14:08 +01:00
config.make.in Make --bindir effective 2019-05-14 11:04:33 -03:00
configure Fix http: URL in 'configure' 2019-09-09 14:16:40 -07:00
configure.ac Fix http: URL in 'configure' 2019-09-09 14:16:40 -07:00
COPYING
COPYING.LIB
extra-lib.mk
gen-locales.mk
INSTALL Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
libc-abis libc-abis: Define ABSOLUTE ABI [BZ #19818][BZ #23307] 2018-07-05 18:06:43 +01:00
libof-iterator.mk
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MAINTAINERS
Makeconfig Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
Makefile Add helper script for glibc debugging 2019-09-30 08:37:18 -03:00
Makefile.in
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o-iterator.mk
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shlib-versions
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version.h Open master for 2.31 development. 2019-08-01 00:41:53 -04:00

This directory contains the sources of the GNU C Library.
See the file "version.h" for what release version you have.

The GNU C Library is the standard system C library for all GNU systems,
and is an important part of what makes up a GNU system.  It provides the
system API for all programs written in C and C-compatible languages such
as C++ and Objective C; the runtime facilities of other programming
languages use the C library to access the underlying operating system.

In GNU/Linux systems, the C library works with the Linux kernel to
implement the operating system behavior seen by user applications.
In GNU/Hurd systems, it works with a microkernel and Hurd servers.

The GNU C Library implements much of the POSIX.1 functionality in the
GNU/Hurd system, using configurations i[4567]86-*-gnu.

When working with Linux kernels, this version of the GNU C Library
requires Linux kernel version 3.2 or later.

Also note that the shared version of the libgcc_s library must be
installed for the pthread library to work correctly.

The GNU C Library supports these configurations for using Linux kernels:

	aarch64*-*-linux-gnu
	alpha*-*-linux-gnu
	arm-*-linux-gnueabi
	csky-*-linux-gnuabiv2
	hppa-*-linux-gnu
	i[4567]86-*-linux-gnu
	x86_64-*-linux-gnu	Can build either x86_64 or x32
	ia64-*-linux-gnu
	m68k-*-linux-gnu
	microblaze*-*-linux-gnu
	mips-*-linux-gnu
	mips64-*-linux-gnu
	powerpc-*-linux-gnu	Hardware or software floating point, BE only.
	powerpc64*-*-linux-gnu	Big-endian and little-endian.
	s390-*-linux-gnu
	s390x-*-linux-gnu
	riscv64-*-linux-gnu
	sh[34]-*-linux-gnu
	sparc*-*-linux-gnu
	sparc64*-*-linux-gnu

If you are interested in doing a port, please contact the glibc
maintainers; see https://www.gnu.org/software/libc/ for more
information.

See the file INSTALL to find out how to configure, build, and install
the GNU C Library.  You might also consider reading the WWW pages for
the C library at https://www.gnu.org/software/libc/.

The GNU C Library is (almost) completely documented by the Texinfo manual
found in the `manual/' subdirectory.  The manual is still being updated
and contains some known errors and omissions; we regret that we do not
have the resources to work on the manual as much as we would like.  For
corrections to the manual, please file a bug in the `manual' component,
following the bug-reporting instructions below.  Please be sure to check
the manual in the current development sources to see if your problem has
already been corrected.

Please see https://www.gnu.org/software/libc/bugs.html for bug reporting
information.  We are now using the Bugzilla system to track all bug reports.
This web page gives detailed information on how to report bugs properly.

The GNU C Library is free software.  See the file COPYING.LIB for copying
conditions, and LICENSES for notices about a few contributions that require
these additional notices to be distributed.  License copyright years may be
listed using range notation, e.g., 1996-2015, indicating that every year in
the range, inclusive, is a copyrightable year that would otherwise be listed
individually.