binutils-gdb/gdb/compile/compile-object-load.h
Jan Kratochvil 7f36105668 compile: Use also inferior munmap
Currently inferior memory is allocated by inferior mmap() but it is never
deallocated; despite the injected objfile incl. its symbols is freed.  This was
intentional so that one can do for example:
inferior:
	char *str = "foo";
GDB:
	(gdb) compile code str = "bar";

I believe later patches will be needed to introduce full control over keeping
vs. discarding the injected module as being discussed in:
	compile: objfiles lifetime UI
	https://sourceware.org/ml/gdb/2015-04/msg00051.html
	Message-ID: <20150429135735.GA16974@host1.jankratochvil.net>
	https://sourceware.org/ml/gdb/2015-05/msg00007.html

As decided by Phil it is better not to leak inferior pages as users can
workaround the issue above for example by:
	(gdb) compile code str = strdup ("bar");

I have checked that in fact gdb/doc/ (written by Phil) already expects the
injected code will be unmapped so that does not need to be changed:
	compile code int ff = 5; p = &ff;
	In this example, @code{p} would point to @code{ff} when the
	@code{compile} command is executing the source code provided to it.
	However, as variables in the (example) program persist with their
	assigned values, the variable @code{p} would point to an invalid
	location when the command exists.

gdb/ChangeLog
2015-04-28  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* arch-utils.c (default_infcall_munmap): New.
	* arch-utils.h (default_infcall_munmap): New declaration.
	* compile/compile-object-load.c (struct munmap_list, munmap_list_add)
	(munmap_list_free, munmap_listp_free_cleanup): New.
	(struct setup_sections_data): Add field munmap_list_headp.
	(setup_sections): Call munmap_list_add.
	(compile_object_load): New variable munmap_list_head, initialize
	setup_sections_data.munmap_list_headp, return munmap_list_head.
	* compile/compile-object-load.h (struct munmap_list): New declaration.
	(struct compile_module): Add field munmap_list_head.
	(munmap_list_free): New declaration.
	* compile/compile-object-run.c (struct do_module_cleanup): Add field
	munmap_list_head.
	(do_module_cleanup): Call munmap_list_free.
	(compile_object_run): Pass munmap_list_head to do_module_cleanup.
	* gdbarch.c: Regenerate.
	* gdbarch.h: Regenerate.
	* gdbarch.sh (infcall_munmap): New.
	* linux-tdep.c (linux_infcall_munmap): New.
	(linux_init_abi): Install it.

gdb/testsuite/ChangeLog
2015-04-28  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* gdb.compile/compile.exp (keep jit in memory): Rename to ...
	(do not keep jit in memory): ... this.
	(expect 5): Change it to ...
	(expect no 5): ... this.
2015-06-03 21:26:04 +02:00

61 lines
1.9 KiB
C

/* Header file to load module for 'compile' command.
Copyright (C) 2014-2015 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#ifndef GDB_COMPILE_OBJECT_LOAD_H
#define GDB_COMPILE_OBJECT_LOAD_H
struct munmap_list;
struct compile_module
{
/* objfile for the compiled module. */
struct objfile *objfile;
/* .c file OBJFILE was built from. It needs to be xfree-d. */
char *source_file;
/* Inferior function GCC_FE_WRAPPER_FUNCTION. */
struct symbol *func_sym;
/* Inferior registers address or NULL if the inferior function does not
require any. */
CORE_ADDR regs_addr;
/* The "scope" of this compilation. */
enum compile_i_scope_types scope;
/* User data for SCOPE in use. */
void *scope_data;
/* Inferior parameter out value type or NULL if the inferior function does not
have one. */
struct type *out_value_type;
/* If the inferior function has an out value, this is its address.
Otherwise it is zero. */
CORE_ADDR out_value_addr;
/* Track inferior memory reserved by inferior mmap. */
struct munmap_list *munmap_list_head;
};
extern struct compile_module *compile_object_load
(const char *object_file, const char *source_file,
enum compile_i_scope_types scope, void *scope_data);
extern void munmap_list_free (struct munmap_list *head);
#endif /* GDB_COMPILE_OBJECT_LOAD_H */