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Pedro Alves 4a556533cf Fix PR11094: JIT breakpoint is not properly recreated on reruns
Even though this was supposedly in the gdb 7.2 timeframe, the testcase
in PR11094 crashes current GDB with a segfault:

  Program received signal SIGSEGV, Segmentation fault.
  0x00000000005ee894 in event_location_to_string (location=0x0) at
  src/gdb/location.c:412
  412       if (EL_STRING (location) == NULL)
  (top-gdb) bt
  #0  0x00000000005ee894 in event_location_to_string (location=0x0) at
  src/gdb/location.c:412
  #1  0x000000000057411a in print_breakpoint_location (b=0x18288e0, loc=0x0) at
  src/gdb/breakpoint.c:6201
  #2  0x000000000057483f in print_one_breakpoint_location (b=0x18288e0,
  loc=0x182cf10, loc_number=0, last_loc=0x7fffffffd258, allflag=1)
      at src/gdb/breakpoint.c:6473
  #3  0x00000000005751e1 in print_one_breakpoint (b=0x18288e0,
  last_loc=0x7fffffffd258, allflag=1) at
  src/gdb/breakpoint.c:6707
  #4  0x000000000057589c in breakpoint_1 (args=0x0, allflag=1, filter=0x0) at
  src/gdb/breakpoint.c:6947
  #5  0x0000000000575aa8 in maintenance_info_breakpoints (args=0x0, from_tty=0)
  at src/gdb/breakpoint.c:7026
  [...]

This is GDB trying to print the location spec of the JIT event
breakpoint, but that's an internal breakpoint without one.

If I add a NULL check, then we see that the JIT breakpoint is now
pending (because its location has shlib_disabled set):

  (gdb) maint info breakpoints
  Num     Type           Disp Enb Address            What
  [...]
  -8      jit events     keep y   <PENDING>           inf 1
  [...]

But that's incorrect.  GDB should have managed to recreate the JIT
breakpoint's location for the second run.  So the problem is
elsewhere.

The problem is that if the JIT loads at the same address on the second
run, we never recreate the JIT breakpoint, because we hit this early
return:

  static int
  jit_breakpoint_re_set_internal (struct gdbarch *gdbarch,
				  struct jit_program_space_data *ps_data)
  {
    [...]
    if (ps_data->cached_code_address == addr)
      return 0;

    [...]
      delete_breakpoint (ps_data->jit_breakpoint);
    [...]
    ps_data->jit_breakpoint = create_jit_event_breakpoint (gdbarch, addr);

Fix this by deleting the breakpoint and discarding the cached code
address when the objfile where the previous JIT breakpoint was found
is deleted/unloaded in the first place.

The test that was originally added for PR11094 doesn't trip on this
because:

  #1 - It doesn't test the case of the JIT descriptor's address _not_
       changing between reruns.

  #2 - And then it doesn't do "maint info breakpoints", or really
       anything with the JIT at all.

  #3 - and even then, to trigger the problem the JIT descriptor needs
       to be in a separate library, while the current test puts it in
       the main program.

The patch extends the test to cover all combinations of these
scenarios.

gdb/ChangeLog:
2016-10-06  Pedro Alves  <palves@redhat.com>

	* jit.c (free_objfile_data): Delete the JIT breakpoint and clear
	the cached code address.

gdb/testsuite/ChangeLog:
2016-10-06  Pedro Alves  <palves@redhat.com>

	* gdb.base/jit-simple-dl.c: New file.
	* gdb.base/jit-simple-jit.c: New file, factored out from ...
	* gdb.base/jit-simple.c: ... this.
	* gdb.base/jit-simple.exp (jit_run): Delete.
	(build_jit): New proc.
	(jit_test_reread): Recompile either the main program or the shared
	library, depending on what is being tested.  Skip changing address
	if caller wants to.  Compare before/after addresses.  If testing
	standalone, explicitly load the binary.  Test "maint info
	breakpoints".
	(top level): Add "standalone vs shared lib" and "change address"
	vs "same address" axes.
2016-10-06 12:53:52 +01:00
bfd Automatic date update in version.in 2016-10-06 00:00:20 +00:00
binutils -Wimplicit-fallthrough warning fixes 2016-10-06 10:13:15 +10:30
config Sync top level files with gcc. 2016-02-10 10:54:29 +00:00
cpu Correct fr30 comment 2016-03-03 12:55:30 +10:30
elfcpp Add support for MIPS .rld_map section. 2016-06-20 12:16:26 -07:00
etc Fix compile time warning messages building with gcc v6.1.1 2016-06-13 10:49:26 +01:00
gas Refine .cfi_sections check to only consider compact eh_frame 2016-10-06 12:46:09 +01:00
gdb Fix PR11094: JIT breakpoint is not properly recreated on reruns 2016-10-06 12:53:52 +01:00
gold [GOLD] -Wimplicit-fallthrough warning fixes 2016-10-06 09:36:33 +10:30
gprof Remove redundant assignment in gprof. 2016-10-06 12:51:47 +01:00
include Disallow 3-operand cmp[l][i] for ppc64 2016-09-29 15:12:47 +09:30
intl Regen intl/configure 2015-08-31 12:53:36 +09:30
ld -Wimplicit-fallthrough warning fixes 2016-10-06 10:13:15 +10:30
libdecnumber Remove leading/trailing white spaces in ChangeLog 2015-07-24 04:16:47 -07:00
libiberty Synchronize libiberty sources with FSF GCC mainline version. 2016-08-02 13:26:28 +01:00
opcodes -Wimplicit-fallthrough warning fixes 2016-10-06 10:13:15 +10:30
readline Improve MinGW support in Readline 2016-09-17 11:50:37 +03:00
sim sim: m68hc11: use standard STATIC_INLINE helper 2016-08-16 06:12:39 -07:00
texinfo
zlib Regenerate configure 2016-05-09 17:24:30 +09:30
.cvsignore
.gitattributes Add a .gitattributes file for use with git-merge-changelog 2014-07-25 18:07:23 -04:00
.gitignore Add archives and make stamps to the .gitignore file. 2016-09-27 15:10:42 +01:00
ChangeLog Add archives and make stamps to the .gitignore file. 2016-09-27 15:10:42 +01:00
compile Update from upstream Automake 2014-11-16 13:43:48 +01:00
config-ml.in Sync toplevel files with GCC 2015-07-27 07:49:05 -07:00
config.guess Fix typo introduced during the most recent synchronization update. 2016-05-27 14:34:06 +01:00
config.rpath
config.sub Sync config.guess and config.sub with FSF GCC mainline versions 2016-05-23 11:42:17 +01:00
configure Enable the configuration of GDB for the NDS32 target. 2016-07-20 09:06:39 +01:00
configure.ac Enable the configuration of GDB for the NDS32 target. 2016-07-20 09:06:39 +01:00
COPYING
COPYING.LIB
COPYING.LIBGLOSS 2013-01-07 Jeff Johnston <jjohnstn@redhat.com> 2013-01-07 21:39:26 +00:00
COPYING.NEWLIB 2013-10-01 Jeff Johnston <jjohnstn@redhat.com> 2013-10-01 18:14:04 +00:00
COPYING3
COPYING3.LIB
depcomp Update from upstream Automake 2014-11-16 13:43:48 +01:00
djunpack.bat
install-sh Update from upstream Automake 2014-11-16 13:43:48 +01:00
libtool.m4 Sync top-level btool.m4 with GCC 2016-01-12 08:44:52 -08:00
ltgcc.m4
ltmain.sh PR target/59788 2014-02-06 11:01:57 +01:00
ltoptions.m4
ltsugar.m4
ltversion.m4
lt~obsolete.m4
MAINTAINERS Update description of ownership of files in include/ 2014-11-04 16:14:14 -08:00
Makefile.def Sync top-level Makefile.def with GCC 2016-01-12 08:34:40 -08:00
Makefile.in Add dependencies to configure rule 2016-05-28 22:36:04 +09:30
Makefile.tpl Add dependencies to configure rule 2016-05-28 22:36:04 +09:30
makefile.vms
missing Update from upstream Automake 2014-11-16 13:43:48 +01:00
mkdep
mkinstalldirs Update from upstream Automake 2014-11-16 13:43:48 +01:00
move-if-change Update `move-if-change' from gnulib 2014-11-16 17:04:02 +01:00
README
README-maintainer-mode
setup.com
src-release.sh fix gdb version parsing in src-release.sh 2016-01-17 10:01:55 +04:00
symlink-tree
ylwrap Update from upstream Automake 2014-11-16 13:43:48 +01:00

		   README for GNU development tools

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