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gdb.base/sym-file.exp, hide guts of the custom loader.

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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.
This commit is contained in:
Pedro Alves 2014-04-15 14:02:34 +01:00
parent eb4c17106b
commit 35e5d2f0f8
4 changed files with 142 additions and 106 deletions
Download patch file Download diff file Expand all files Collapse all files

114
gdb/testsuite/gdb.base/sym-file-loader.c
View file

@ -23,6 +23,59 @@
#include "sym-file-loader.h"
#include <inttypes.h>
#include <ansidecl.h>
#include <elf/common.h>
#include <elf/external.h>
#ifdef TARGET_LP64
typedef Elf64_External_Phdr Elf_External_Phdr;
typedef Elf64_External_Ehdr Elf_External_Ehdr;
typedef Elf64_External_Shdr Elf_External_Shdr;
typedef Elf64_External_Sym Elf_External_Sym;
typedef uint64_t Elf_Addr;
#elif defined TARGET_ILP32
typedef Elf32_External_Phdr Elf_External_Phdr;
typedef Elf32_External_Ehdr Elf_External_Ehdr;
typedef Elf32_External_Shdr Elf_External_Shdr;
typedef Elf32_External_Sym Elf_External_Sym;
typedef uint32_t Elf_Addr;
#endif
#define GET(hdr, field) (\
sizeof ((hdr)->field) == 1 ? (uint64_t) (hdr)->field[0] : \
sizeof ((hdr)->field) == 2 ? (uint64_t) *(uint16_t *) (hdr)->field : \
sizeof ((hdr)->field) == 4 ? (uint64_t) *(uint32_t *) (hdr)->field : \
sizeof ((hdr)->field) == 8 ? *(uint64_t *) (hdr)->field : \
*(uint64_t *) NULL)
#define GETADDR(hdr, field) (\
sizeof ((hdr)->field) == sizeof (Elf_Addr) ? *(Elf_Addr *) (hdr)->field : \
*(Elf_Addr *) NULL)
struct segment
{
uint8_t *mapped_addr;
Elf_External_Phdr *phdr;
struct segment *next;
};
struct library
{
int fd;
Elf_External_Ehdr *ehdr;
struct segment *segments;
};
static Elf_External_Shdr *find_shdr (Elf_External_Ehdr *ehdr,
const char *section);
static int translate_offset (uint64_t file_offset, struct segment *seg,
void **addr);
#ifdef TARGET_LP64
uint8_t
@ -123,10 +176,10 @@ get_origin (void)
/* Mini shared library loader. No reallocation
is performed for the sake of simplicity. */
int
load_shlib (const char *file, Elf_External_Ehdr **ehdr_out,
struct segment **seg_out)
struct library *
load_shlib (const char *file)
{
struct library *lib;
uint64_t i;
int fd = -1;
off_t fsize;
@ -148,7 +201,7 @@ load_shlib (const char *file, Elf_External_Ehdr **ehdr_out,
if (origin == NULL)
{
fprintf (stderr, "get_origin not implemented.");
return -1;
return NULL;
}
path = alloca (strlen (origin) + 1 + strlen (file) + 1);
@ -162,7 +215,7 @@ load_shlib (const char *file, Elf_External_Ehdr **ehdr_out,
if (fd < 0)
{
perror ("fopen failed.");
return -1;
return NULL;
}
fsize = lseek (fd, 0, SEEK_END);
@ -170,14 +223,14 @@ load_shlib (const char *file, Elf_External_Ehdr **ehdr_out,
if (fsize < 0)
{
perror ("lseek failed.");
return -1;
return NULL;
}
addr = (uint8_t *) mmap (NULL, fsize, PROT_READ, MAP_PRIVATE, fd, 0);
if (addr == (uint8_t *) -1)
{
perror ("mmap failed.");
return -1;
return NULL;
}
/* Check if the lib is an ELF file. */
@ -188,7 +241,7 @@ load_shlib (const char *file, Elf_External_Ehdr **ehdr_out,
|| ehdr->e_ident[EI_MAG3] != ELFMAG3)
{
printf ("Not an ELF file: %x\n", ehdr->e_ident[EI_MAG0]);
return -1;
return NULL;
}
if (ehdr->e_ident[EI_CLASS] == ELFCLASS32)
@ -196,7 +249,7 @@ load_shlib (const char *file, Elf_External_Ehdr **ehdr_out,
if (sizeof (void *) != 4)
{
printf ("Architecture mismatch.");
return -1;
return NULL;
}
}
else if (ehdr->e_ident[EI_CLASS] == ELFCLASS64)
@ -204,10 +257,19 @@ load_shlib (const char *file, Elf_External_Ehdr **ehdr_out,
if (sizeof (void *) != 8)
{
printf ("Architecture mismatch.");
return -1;
return NULL;
}
}
lib = malloc (sizeof (struct library));
if (lib == NULL)
{
printf ("malloc failed.");
return NULL;
}
lib->fd = fd;
/* Load the program segments. For the sake of simplicity
assume that no reallocation is needed. */
phdr = (Elf_External_Phdr *) (addr + GET (ehdr, e_phoff));
@ -223,8 +285,25 @@ load_shlib (const char *file, Elf_External_Ehdr **ehdr_out,
head_seg = next_seg;
}
}
*ehdr_out = ehdr;
*seg_out = head_seg;
lib->ehdr = ehdr;
lib->segments = head_seg;
return lib;
}
int
get_text_addr (struct library *lib, void **text_addr)
{
Elf_External_Shdr *text;
/* Get the text section. */
text = find_shdr (lib->ehdr, ".text");
if (text == NULL)
return -1;
if (translate_offset (GET (text, sh_offset), lib->segments, text_addr)
!= 0)
return -1;
return 0;
}
@ -289,7 +368,7 @@ find_strtab (Elf_External_Ehdr *ehdr,
/* Return the section header named SECTION. */
Elf_External_Shdr *
static Elf_External_Shdr *
find_shdr (Elf_External_Ehdr *ehdr, const char *section)
{
uint64_t shstrtab_size = 0;
@ -317,7 +396,7 @@ find_shdr (Elf_External_Ehdr *ehdr, const char *section)
/* Return the symbol table. */
Elf_External_Sym *
static Elf_External_Sym *
find_symtab (Elf_External_Ehdr *ehdr, uint64_t *symtab_size)
{
uint64_t i;
@ -337,7 +416,7 @@ find_symtab (Elf_External_Ehdr *ehdr, uint64_t *symtab_size)
/* Translate a file offset to an address in a loaded segment. */
int
static int
translate_offset (uint64_t file_offset, struct segment *seg, void **addr)
{
while (seg)
@ -369,14 +448,15 @@ translate_offset (uint64_t file_offset, struct segment *seg, void **addr)
/* Lookup the address of FUNC. */
int
lookup_function (const char *func,
Elf_External_Ehdr *ehdr, struct segment *seg, void **addr)
lookup_function (struct library *lib, const char *func, void **addr)
{
const char *strtab;
uint64_t strtab_size = 0;
Elf_External_Sym *symtab;
uint64_t symtab_size = 0;
uint64_t i;
Elf_External_Ehdr *ehdr = lib->ehdr;
struct segment *seg = lib->segments;
/* Get the string table for the symbols. */
strtab = find_strtab (ehdr, ".strtab", &strtab_size);