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Tom de Vries 6e41445bb0 [gdb/testsuite] Make gdb.base/longjmp.exp FAIL more stable across archs
When running test-case gdb.base/longjmp.exp on x86_64-linux, the master
longjmp breakpoint is set using probes and the test-case passes:
...
(gdb) PASS: gdb.base/longjmp.exp: next to longjmp (1)
next^M
0x00000000004005cc      49        if (setjmp (env) == 0) /* patt1 */^M
(gdb) PASS: gdb.base/longjmp.exp: next over longjmp(1)
next^M
56            resumes++;^M
(gdb) PASS: gdb.base/longjmp.exp: next into else block (1)
...

However, if I disable
create_longjmp_master_breakpoint_probe, we have instead:
...
(gdb) PASS: gdb.base/longjmp.exp: next to longjmp (1)
next^M
56            resumes++;^M
(gdb) FAIL: gdb.base/longjmp.exp: next over longjmp(1)
...

At first glance, the failure mode doesn't look too bad: we stop
a few insns later than the passing scenario.

For contrast, if we do the same on powerpc64le, the failure mode is:
...
(gdb) PASS: gdb.base/longjmp.exp: next to longjmp (1)
next^M
^M
Breakpoint 3, main () at longjmp.c:59^M
59        i = 1; /* miss_step_1 */^M
(gdb) FAIL: gdb.base/longjmp.exp: next over longjmp(1)
...
Here we only stop because of running into the safety net breakpoint at
miss_step_1.

So, how does this happen on x86_64?  Let's look at the code:
...
4005c7: e8 94 fe ff ff    call 400460 <_setjmp@plt>
4005cc: 85 c0             test %eax,%eax
4005ce: 75 1e             jne  4005ee <main+0x3b>
4005d0: 8b 05 8e 0a 20 00 mov  0x200a8e(%rip),%eax # 601064 <longjmps>
4005d6: 83 c0 01          add  $0x1,%eax
4005d9: 89 05 85 0a 20 00 mov  %eax,0x200a85(%rip) # 601064 <longjmps>
4005df: be 01 00 00 00    mov  $0x1,%esi
4005e4: bf 80 10 60 00    mov  $0x601080,%edi
4005e9: e8 82 fe ff ff    call 400470 <longjmp@plt>
4005ee: 8b 05 74 0a 20 00 mov  0x200a74(%rip),%eax # 601068 <resumes>
...
The next over the longjmp call at 4005e9 is supposed to stop at the longjmp
target at 4005cc, but instead we stop at 4005ee, where we have the step-resume
breakpoint inserted by the next.  In other words, we accidentally "return"
from the longjmp call to the insn immediately after it (even though
a longjmp is a noreturn function).

Try to avoid this accident and make the failure mode on x86_64 the same as on
powerpc64le, by switching the then and else branch.

Tested on x86_64-linux.
2022-12-06 12:01:46 +01:00
bfd Get rid of SEC_ELF_COMPRESS 2022-12-06 15:08:31 +10:30
binutils Get rid of SEC_ELF_RENAME 2022-12-06 14:40:10 +10:30
config libsframe: add the SFrame library 2022-11-15 15:24:29 -08:00
contrib Import mklog.py from gcc repo 2020-09-25 10:24:44 -04:00
cpu Add markers for 2.39 branch 2022-07-08 10:41:07 +01:00
elfcpp gold, dwp: support zstd compressed input debug sections [PR 29641] 2022-11-10 21:42:14 -08:00
etc Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
gas gas: add Dwarf line number test for .macro expansions 2022-12-05 13:52:55 +01:00
gdb [gdb/testsuite] Make gdb.base/longjmp.exp FAIL more stable across archs 2022-12-06 12:01:46 +01:00
gdbserver gdbserver: switch to right process in find_one_thread 2022-11-28 09:13:30 -05:00
gdbsupport fix leak in gdb_environ 2022-11-27 21:08:24 +01:00
gnulib [PR build/29791] gnulib: Disable _GL_ATTRIBUTE_DEALLOC on Solaris 2022-11-20 14:55:52 +01:00
gold Re: gold: add --compress-debug-sections=zstd [PR 29641] 2022-11-11 18:05:36 +10:30
gprof Updated Hungarian translation for the gprof sub-directory. 2022-10-21 10:55:57 +01:00
gprofng gprofng: remove unused gprofng/src/DbeSession.cc.1 2022-11-28 20:52:10 -08:00
include xtensa: allow dynamic configuration 2022-11-28 18:16:12 -08:00
intl egrep in binutils 2022-09-28 13:37:31 +09:30
ld Prevent an illegal memory access when comparing the prefix of a section name regexp. 2022-12-05 14:57:17 +00:00
libbacktrace testsuite: support mold linker 2022-12-05 15:52:51 +01:00
libctf libctf: use libtool for link test in configure 2022-11-11 22:01:25 -08:00
libdecnumber Merge config/ changes from GCC, to enable DFP on AArch64 2022-05-24 10:47:29 +01:00
libiberty Impport libiberty commit: 885b6660c17f from gcc mainline. Fix gas's acinclude.m4 to stop a potwntial configure time warning message. 2022-11-24 12:31:46 +00:00
libsframe sframe/doc: remove usage of xrefautomaticsectiontitle 2022-11-24 10:14:08 -08:00
opcodes x86: Remove unnecessary vex.w check for xh_mode in disassembler 2022-12-06 15:49:40 +08:00
readline gdb/readline: fix extra 'quit' message problem 2022-05-07 10:49:27 +01:00
sim sim: pru: Fix behaviour when loop count is zero 2022-11-12 15:10:07 +02:00
texinfo
zlib Regenerate with automake-1.15.1 2022-07-09 20:10:47 +09:30
.cvsignore
.editorconfig Add top-level .editorconfig file 2022-01-28 08:25:42 -05:00
.gitattributes binutils-gdb/git: highlight whitespace errors in source files 2022-07-25 14:35:41 +01:00
.gitignore Add gnu global outputs to .gitignore 2020-12-02 10:00:27 -05:00
ar-lib Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
ChangeLog Add ability to create reproducible source tarballs. 2022-10-10 11:28:45 +01:00
compile
config-ml.in
config.guess Update the config.guess and config.sub files from the master repository and regenerate files. 2022-01-17 16:21:22 +00:00
config.rpath
config.sub Update the config.guess and config.sub files from the master repository and regenerate files. 2022-01-17 16:21:22 +00:00
configure libsframe: add the SFrame library 2022-11-15 15:24:29 -08:00
configure.ac libsframe: add the SFrame library 2022-11-15 15:24:29 -08:00
COPYING
COPYING3
COPYING3.LIB
COPYING.LIB
COPYING.LIBGLOSS
COPYING.NEWLIB
depcomp
djunpack.bat
install-sh
libtool.m4 libtool.m4: fix the NM="/nm/over/here -B/option/with/path" case 2022-03-25 12:02:35 +00:00
lt~obsolete.m4
ltgcc.m4
ltmain.sh
ltoptions.m4
ltsugar.m4
ltversion.m4
MAINTAINERS MAINTAINERS: Update path to readline config.{sub,guess} files 2021-05-24 18:11:49 +02:00
Makefile.def bfd: linker: merge .sframe sections 2022-11-15 15:49:47 -08:00
Makefile.in bfd: linker: merge .sframe sections 2022-11-15 15:49:47 -08:00
Makefile.tpl Pass PKG_CONFIG_PATH down from top-level Makefile 2022-04-08 10:56:41 -04:00
makefile.vms
missing
mkdep
mkinstalldirs
move-if-change
multilib.am Merge autoconf / automake update changes from GCC. 2018-10-31 17:10:56 +00:00
README
README-maintainer-mode Note that at least dejagnu version 1.5.3 is required in order to be ale to run the testsuites. 2022-10-04 10:54:19 +01:00
setup.com
src-release.sh src-release.sh: Fix gdb source tarball build failure due to libsframe 2022-11-30 07:32:58 +04:00
symlink-tree
test-driver Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
ylwrap

		   README for GNU development tools

This directory contains various GNU compilers, assemblers, linkers, 
debuggers, etc., plus their support routines, definitions, and documentation.

If you are receiving this as part of a GDB release, see the file gdb/README.
If with a binutils release, see binutils/README;  if with a libg++ release,
see libg++/README, etc.  That'll give you info about this
package -- supported targets, how to use it, how to report bugs, etc.

It is now possible to automatically configure and build a variety of
tools with one command.  To build all of the tools contained herein,
run the ``configure'' script here, e.g.:

	./configure 
	make

To install them (by default in /usr/local/bin, /usr/local/lib, etc),
then do:
	make install

(If the configure script can't determine your type of computer, give it
the name as an argument, for instance ``./configure sun4''.  You can
use the script ``config.sub'' to test whether a name is recognized; if
it is, config.sub translates it to a triplet specifying CPU, vendor,
and OS.)

If you have more than one compiler on your system, it is often best to
explicitly set CC in the environment before running configure, and to
also set CC when running make.  For example (assuming sh/bash/ksh):

	CC=gcc ./configure
	make

A similar example using csh:

	setenv CC gcc
	./configure
	make

Much of the code and documentation enclosed is copyright by
the Free Software Foundation, Inc.  See the file COPYING or
COPYING.LIB in the various directories, for a description of the
GNU General Public License terms under which you can copy the files.

REPORTING BUGS: Again, see gdb/README, binutils/README, etc., for info
on where and how to report problems.