FreeChainXenon/binutils-gdb
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Handle VDSO section headers past end of page

Browse source 
When a VDSO gets large enough that it doesn't entirely fit in one page,
but not so large that the part described by the program header exceeds
one page, then gdb/BFD doesn't read the section headers and symbol
table information.  This patch cures that by passing the size of the
vdso to BFD, and fixes a number of other issues in the BFD code.

bfd/
	* elfcode.h (bfd_from_remote_memory): Add "size" parameter.
	Consolidate code handling possible section headers past end of
	segment.  Don't use p_align for page size guess, instead use
	minpagesize.  Take note of ld.so clearing section headers when
	p_memsz > p_filesz.  Handle file header specifying no section
	headers.  Handle zero p_align throughout.  Default loadbase to
	zero.  Add comments.  Rename contents_size to high_offset, and
	make it a bfd_vma.  Delete unnecessary bfd_set_error calls.
	* bfd-in.h (bfd_elf_bfd_from_remote_memory): Update prototpe.
	* elf-bfd.h (struct elf_backend_data <elf_backend_from_remote_memory>):
	Likewise.
	(_bfd_elf32_bfd_from_remote_memory): Likewise.
	(_bfd_elf64_bfd_from_remote_memory): Likewise.
	* elf.c (bfd_elf_bfd_from_remote_memory): Adjust.
	* bfd-in2.h: Regnerate.
gdb/
	* symfile-mem.c (symbol_file_add_from_memory): Add size parameter.
	Pass to bfd_elf_bfd_from_remote_memory.  Adjust all callers.
	(struct symbol_file_add_from_memory_args): Add size field.
	(find_vdso_size): New function.
	(add_vsyscall_page): Attempt to find vdso size.
This commit is contained in:
Alan Modra 2014-04-02 12:07:33 +10:30
parent cf2a3e9905
commit 5979d6b69b
8 changed files with 180 additions and 94 deletions
Download patch file Download diff file Expand all files Collapse all files

38
gdb/symfile-mem.c
View file

@ -76,13 +76,14 @@ target_read_memory_bfd (bfd_vma memaddr, bfd_byte *myaddr, bfd_size_type len)
}
/* Read inferior memory at ADDR to find the header of a loaded object file
and read its in-core symbols out of inferior memory. TEMPL is a bfd
and read its in-core symbols out of inferior memory. SIZE, if
non-zero, is the known size of the object. TEMPL is a bfd
representing the target's format. NAME is the name to use for this
symbol file in messages; it can be NULL or a malloc-allocated string
which will be attached to the BFD. */
static struct objfile *
symbol_file_add_from_memory (struct bfd *templ, CORE_ADDR addr, char *name,
int from_tty)
symbol_file_add_from_memory (struct bfd *templ, CORE_ADDR addr,
size_t size, char *name, int from_tty)
{
struct objfile *objf;
struct bfd *nbfd;
@ -95,7 +96,7 @@ symbol_file_add_from_memory (struct bfd *templ, CORE_ADDR addr, char *name,
if (bfd_get_flavour (templ) != bfd_target_elf_flavour)
error (_("add-symbol-file-from-memory not supported for this target"));
nbfd = bfd_elf_bfd_from_remote_memory (templ, addr, &loadbase,
nbfd = bfd_elf_bfd_from_remote_memory (templ, addr, size, &loadbase,
target_read_memory_bfd);
if (nbfd == NULL)
error (_("Failed to read a valid object file image from memory."));
@ -158,7 +159,7 @@ add_symbol_file_from_memory_command (char *args, int from_tty)
error (_("Must use symbol-file or exec-file "
"before add-symbol-file-from-memory."));
symbol_file_add_from_memory (templ, addr, NULL, from_tty);
symbol_file_add_from_memory (templ, addr, 0, NULL, from_tty);
}
/* Arguments for symbol_file_add_from_memory_wrapper. */
@ -167,6 +168,7 @@ struct symbol_file_add_from_memory_args
{
struct bfd *bfd;
CORE_ADDR sysinfo_ehdr;
size_t size;
char *name;
int from_tty;
};
@ -179,8 +181,25 @@ symbol_file_add_from_memory_wrapper (struct ui_out *uiout, void *data)
{
struct symbol_file_add_from_memory_args *args = data;
symbol_file_add_from_memory (args->bfd, args->sysinfo_ehdr, args->name,
args->from_tty);
symbol_file_add_from_memory (args->bfd, args->sysinfo_ehdr, args->size,
args->name, args->from_tty);
return 0;
}
/* Rummage through mappings to find the vsyscall page size. */
static int
find_vdso_size (CORE_ADDR vaddr, unsigned long size,
int read, int write, int exec, int modified,
void *data)
{
struct symbol_file_add_from_memory_args *args = data;
if (vaddr == args->sysinfo_ehdr)
{
args->size = size;
return 1;
}
return 0;
}
@ -217,6 +236,11 @@ add_vsyscall_page (struct target_ops *target, int from_tty)
}
args.bfd = bfd;
args.sysinfo_ehdr = sysinfo_ehdr;
args.size = 0;
if (gdbarch_find_memory_regions_p (target_gdbarch ()))
(void) gdbarch_find_memory_regions (target_gdbarch (),
find_vdso_size, &args);
args.name = xstrprintf ("system-supplied DSO at %s",
paddress (target_gdbarch (), sysinfo_ehdr));
/* Pass zero for FROM_TTY, because the action of loading the