Commit Graph

7 Commits

Author SHA1 Message Date
Joel Brobecker 61baf725ec update copyright year range in GDB files
This applies the second part of GDB's End of Year Procedure, which
updates the copyright year range in all of GDB's files.

gdb/ChangeLog:

        Update copyright year range in all GDB files.
2017-01-01 10:52:34 +04:00
Joel Brobecker 618f726fcb GDB copyright headers update after running GDB's copyright.py script.
gdb/ChangeLog:

        Update year range in copyright notice of all files.
2016-01-01 08:43:22 +04:00
Joel Brobecker 32d0add0a6 Update year range in copyright notice of all files owned by the GDB project.
gdb/ChangeLog:

        Update year range in copyright notice of all files.
2015-01-01 13:32:14 +04:00
Pedro Alves 08351840ea Stale breakpoint instructions, spurious SIGTRAPS.
Without the code portion of the patch, we get these failures:

 FAIL: gdb.base/break-unload-file.exp: always-inserted on: break: continue
 FAIL: gdb.base/break-unload-file.exp: always-inserted on: hbreak: continue
 FAIL: gdb.base/sym-file.exp: stale bkpts: continue to breakpoint: end here

They all looks like random SIGTRAPs:

 continue
 Continuing.

 Program received signal SIGTRAP, Trace/breakpoint trap.
 0x0000000000400541 in foo () at ../../../src/gdb/testsuite/gdb.base/break-unload-file.c:21
 21      }
 (gdb) FAIL: gdb.base/break-unload-file.exp: always-inserted on: break: continue

(This is a regression caused by the remove-symbol-file command
series.)

break-unload-file.exp is about having breakpoints inserted, and then
doing "file".  I caught this while writing a test that does "file
PROGRAM", while PROGRAM was already loaded, which internally does
"file" first, because I wanted to force a breakpoint_re_set, but the
test is more explicit in case GDB ever optimizes out that re-set.

The problem is that unloading the file with "file" ends up in
disable_breakpoints_in_freed_objfile, which marks all breakpoint
locations of the objfile as both shlib_disabled, _and_ clears the
inserted flag, without actually removing the breakpoints from the
inferior.  Now, usually, in all-stop, breakpoints will already be
removed from the inferior before the user can issue the "file"
command, but, with non-stop, or breakpoints always-inserted on mode,
breakpoints stay inserted even while the user has the prompt.  In the
latter case, then, if we let the program continue, and it executes the
address where we had previously set the breakpoint, it'll actually
execute the breakpoint instruction that we left behind...

Now, one issue is that the intent of
disable_breakpoints_in_freed_objfile is really to handle the unloading
of OBJF_USERLOADED objfiles.  These are objfiles that were added with
add-symbol-file and that are removed with remove-symbol-file.

"add-symbol-file"'s docs in the manual clearly say these commands are
used to let GDB know about dynamically loaded code:

 You would use this command when @var{filename} has been dynamically
 loaded (by some other means) into the program that is running.

Similarly, the online help says:

 (gdb) help add-symbol-file
 Load symbols from FILE, assuming FILE has been dynamically loaded.

So it makes sense to, like when shared libraries are unloaded through
the generic solib machinery, mark the breakpoint locations as
shlib_disabled.  But, the "file" command is not about dynamically
loaded code, it's about the main program.  So the patch makes
disable_breakpoints_in_freed_objfile skip all objfiles but
OBJF_USERLOADED ones, thus skipping the main objfile.

Then, the reason that disable_breakpoints_in_freed_objfile was
clearing the inserted flag isn't clear, but likely to avoid breakpoint
removal errors, assuming remove-symbol-file was called after the
dynamic object was already unmapped from the inferior.  In that case,
it'd okay to simply clear the inserted flag, but not so if the user
for example does remove-symbol-file to remove the library because he
made a mistake in the library's address, and wants to re-do
add-symbol-file with the correct address.

To address all that, I propose an alternative implementation, that
handles both cases.  The patch includes changes to sym-file.exp to
cover them.

This implementation leaves the inserted flag alone, and handles
breakpoint insertion/removal failure gracefully when the locations are
in OBJF_USERLOADED objfiles, just like we handle insertion/removal
failure gracefully for locations in shared libraries.

To try to make sure we aren't patching back stale shadow memory
contents into the inferior, in case the program mapped a different
library at the same address where we had the breakpoint, without the
user having had a chance of remove-symbol-file'ing before, this adds a
new memory_validate_breakpoint function that checks if the breakpoint
instruction is still in memory.  ppc_linux_memory_remove_breakpoint
does this unconditionally for all memory breakpoints, and questions
whether memory_remove_breakpoint should be changed to do this for all
breakpoints.  Possibly yes, though I'm not certain, hence this
baby-steps patch.

Tested on x86_64 Fedora 17, native and gdbserver.

gdb/
2014-04-23  Pedro Alves  <palves@redhat.com>

	* breakpoint.c (insert_bp_location): Tolerate errors if the
	breakpoint is set in a user-loaded objfile.
	(remove_breakpoint_1): Likewise.  Also tolerate errors if the
	location is marked shlib_disabled.  If the breakpoint is set in a
	user-loaded objfile is a GDB-side memory breakpoint, validate it
	before uninsertion.  (disable_breakpoints_in_freed_objfile): Skip
	non-OBJF_USERLOADED objfiles.  Don't clear the location's inserted
	flag.
	* mem-break.c (memory_validate_breakpoint): New function.
	* objfiles.c (userloaded_objfile_contains_address_p): New
	function.
	* objfiles.h (userloaded_objfile_contains_address_p): Declare.
	* target.h (memory_validate_breakpoint): New declaration.

gdb/testsuite/
2014-04-23  Pedro Alves  <palves@redhat.com>

	* gdb.base/break-unload-file.c: New file.
	* gdb.base/break-unload-file.exp: New file.
	* gdb.base/sym-file-lib.c (baz): New function.
	* gdb.base/sym-file-loader.c (struct segment) <mapped_size>: New
	field.
	(load): Store the segment's mapped size.
	(unload): New function.
	(unload_shlib): New function.
	* gdb.base/sym-file-loader.h (unload_shlib): New declaration.
	* gdb.base/sym-file-main.c (main): Unload, and reload the library,
	set a breakpoint at baz, and call it.
	* gdb.base/sym-file.exp: New tests for stale breakpoint
	instructions.
2014-04-23 15:09:27 +01:00
Pedro Alves 35e5d2f0f8 gdb.base/sym-file.exp, hide guts of the custom loader.
This test uses a simple custom elf loader, implemented in
gdb.base/sym-file-loader.h|c.  This loader doesn't have a dlclose-like
function today, but I'll need one.  But, I found that the guts of the
loader are exposed too much to the client, making the interface more
complicated than necessary.  It's simpler if the loader just exports a
few dlopen/dlsym -style functions.  That's what this patch does.

Tested on x86_86 Fedora 17, native and gdbserver.

gdb/testsuite/
2014-04-15  Pedro Alves  <palves@redhat.com>

	* gdb.base/sym-file-loader.h: Move inclusion of <inttypes.h>,
	<ansidecl.h>, <elf/common.h> and <elf/external.h> to
	sym-file-loader.c.
	(Elf_External_Phdr, Elf_External_Ehdr, Elf_External_Shdr)
	(Elf_External_Sym, Elf_Addr, GET, GETADDR, struct segment): Move
	to sym-file-loader.c.
	(struct library): Forward declare.
	(load_shlib, lookup_function): Change prototypes.
	(find_shstrtab, find_strtab, find_shdr, find_symtab)
	(translate_offset): Remove declarations.
	(get_text_addr): New declaration.
	* gdb.base/sym-file-loader.c: Move inclusion of <inttypes.h>,
	<ansidecl.h>, <elf/common.h> and <elf/external.h> here from
	sym-file-loader.h.
	(Elf_External_Phdr, Elf_External_Ehdr, Elf_External_Shdr)
	(Elf_External_Sym, Elf_Addr, GET, GETADDR, struct segment): Move
	here from sym-file-loader.h.
	(struct library): New structure.
	(load_shlib, lookup_function): Change prototypes and adjust to
	work with a struct library.
	(find_shstrtab, find_strtab, find_shdr, find_symtab)
	(translate_offset): Make static.
	(get_text_addr): New function.
	* gdb.base/sym-file-main.c (main): Adjust to new loader interface.
2014-04-15 14:23:37 +01:00
Joel Brobecker ecd75fc8ee Update Copyright year range in all files maintained by GDB. 2014-01-01 07:54:24 +04:00
Nicolas Blanc 681f229a9f Test adding and removing a symbol file at runtime.
This test exercises the commands 'add-symbol-file'
and 'remove-symbol-file'.

2013-10-29  Nicolas Blanc  <nicolas.blanc@intel.com>

gdb/testsuite
	* gdb.base/sym-file-lib.c: New file.
	* gdb.base/sym-file-loader.c: New file.
	* gdb.base/sym-file-loader.h: New file.
	* gdb.base/sym-file-main.c: New file.
	* gdb.base/sym-file.exp: New file.

Signed-off-by: Nicolas Blanc <nicolas.blanc@intel.com>
2013-10-29 10:56:45 +01:00