grub/kern/dl.c
okuji a5ffe96617 2003-01-06 Yoshinori K. Okuji <okuji@enbug.org>
* util/i386/pc/pupa-setup.c: Include pupa/machine/kernel.h.
	(setup): Configure the installed partition information and the
	dl prefix.

	* loader/i386/pc/chainloader.c (my_mod): New variable.
	(pupa_chainloader_unload): New function.
	(pupa_rescue_cmd_chainloader): Refer itself.
	(PUPA_MOD_INIT): Save its own module in MY_MOD.

	* kern/i386/pc/startup.S (install_partition): Removed.
	(version_string): Likewise.
	(config_file): Likewise.
	(pupa_install_dos_part): New variable.
	(pupa_install_bsd_part): Likewise.
	(pupa_prefix): Likewise.
	(pupa_chainloader_real_boot): Call pupa_dl_unload_all.

	* kern/i386/pc/init.c: Include pupa/machine/kernel.h, pupa/dl.h
	and pupa/misc.h.
	(make_install_device): New function.
	(pupa_machine_init): Set the dl prefix.

	* kern/rescue.c: Include pupa/rescue.h and pupa/dl.h.
	(buf): Renamed to ...
	(linebuf): ... this.
	(pupa_rescue_cmd_prefix): New function.
	(pupa_rescue_cmd_insmod): Likewise.
	(pupa_rescue_cmd_rmmod): Likewise.
	(pupa_rescue_cmd_lsmod): Likewise.
	(pupa_enter_rescue_mode): Register new commands: prefix, insmod,
	rmmod and lsmod.

	* kern/mm.c (pupa_memalign): If failed even after invalidating
	disk caches, unload unneeded modules and retry.

	* kern/misc.c (pupa_memmove): New function.
	(pupa_memcpy): Removed.
	(pupa_strcpy): New function.
	(pupa_itoa): Made static.

	* kern/dl.c (pupa_dl_iterate): New function.
	(pupa_dl_ref): Likewise.
	(pupa_dl_unref): Likewise.
	(pupa_dl_unload): Return if succeeded or not.
	(pupa_dl_unload_unneeded): New function.
	(pupa_dl_unload_all): Likewise.
	(pupa_dl_init): Renamed to ...
	(pupa_dl_set_prefix): ... this.
	(pupa_dl_get_prefix): New function.

	* include/pupa/i386/pc/kernel.h: Include pupa/types.h.
	(PUPA_KERNEL_MACHINE_INSTALL_DOS_PART): New macro.
	(PUPA_KERNEL_MACHINE_INSTALL_BSD_PART): Likewise.
	(PUPA_KERNEL_MACHINE_PREFIX): Likewise.
	(pupa_install_dos_part): Declared.
	(pupa_install_bsd_part): Likewise.
	(pupa_prefix): Likewise.
	(pupa_boot_drive): Likewise.

	* include/pupa/types.h: Fix a typo.

	* include/pupa/misc.h (pupa_memcpy): New macro. Just an alias to
	pupa_memmove.
	(pupa_memmove): Declared.
	(pupa_strcpy): Likewise.

	* include/pupa/dl.h (PUPA_MOD_INIT): Change the prototype. Now
	pupa_mod_init takes one argument, its own module.
	(pupa_dl_unload_unneeded): Declared.
	(pupa_dl_unload_all): Likewise.
	(pupa_dl_ref): Likewise.
	(pupa_dl_unref): Likewise.
	(pupa_dl_iterate): Likewise.
	(pupa_dl_init): Renamed to ...
	(pupa_dl_set_prefix): ... this.
	(pupa_dl_get_prefix): Declared.

	* fs/fat.c [!PUPA_UTIL] (my_mod): New variable.
	(pupa_fat_dir) [!PUPA_UTIL]: Prevent the fat module from being
	unloaded.
	(pupa_fat_open) [!PUPA_UTIL]: Refer itself if succeeded.
	(pupa_fat_close) [!PUPA_UTIL]: Unrefer itself.

	* configure.ac (tmp_CFLAGS): Added -Wshadow, -Wpointer-arith,
	-Wmissing-prototypes, -Wundef and -Wstrict-prototypes.
2003-01-06 00:01:35 +00:00

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/* dl.c - loadable module support */
/*
* PUPA -- Preliminary Universal Programming Architecture for GRUB
* Copyright (C) 2002 Yoshinori K. Okuji <okuji@enbug.org>
*
* PUPA 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 2 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 PUPA; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <config.h>
#include <pupa/elf.h>
#include <pupa/dl.h>
#include <pupa/misc.h>
#include <pupa/mm.h>
#include <pupa/err.h>
#include <pupa/types.h>
#include <pupa/symbol.h>
#include <pupa/file.h>
#if PUPA_HOST_SIZEOF_VOID_P == 4
typedef Elf32_Word Elf_Word;
typedef Elf32_Addr Elf_Addr;
typedef Elf32_Ehdr Elf_Ehdr;
typedef Elf32_Shdr Elf_Shdr;
typedef Elf32_Sym Elf_Sym;
# define ELF_ST_BIND(val) ELF32_ST_BIND (val)
# define ELF_ST_TYPE(val) ELF32_ST_TYPE (val)
#elif PUPA_HOST_SIZEOF_VOID_P == 8
typedef Elf64_Word Elf_Word;
typedef Elf64_Addr Elf_Addr;
typedef Elf64_Ehdr Elf_Ehdr;
typedef Elf64_Shdr Elf_Shdr;
typedef Elf64_Sym Elf_Sym;
# define ELF_ST_BIND(val) ELF64_ST_BIND (val)
# define ELF_ST_TYPE(val) ELF64_ST_TYPE (val)
#endif
struct pupa_dl_list
{
struct pupa_dl_list *next;
pupa_dl_t mod;
};
typedef struct pupa_dl_list *pupa_dl_list_t;
static pupa_dl_list_t pupa_dl_head;
static pupa_err_t
pupa_dl_add (pupa_dl_t mod)
{
pupa_dl_list_t l;
if (pupa_dl_get (mod->name))
return pupa_error (PUPA_ERR_BAD_MODULE,
"`%s' is already loaded", mod->name);
l = (pupa_dl_list_t) pupa_malloc (sizeof (*l));
if (! l)
return pupa_errno;
l->mod = mod;
l->next = pupa_dl_head;
pupa_dl_head = l;
return PUPA_ERR_NONE;
}
static void
pupa_dl_remove (pupa_dl_t mod)
{
pupa_dl_list_t *p, q;
for (p = &pupa_dl_head, q = *p; q; p = &q->next, q = *p)
if (q->mod == mod)
{
*p = q->next;
pupa_free (q);
return;
}
}
pupa_dl_t
pupa_dl_get (const char *name)
{
pupa_dl_list_t l;
for (l = pupa_dl_head; l; l = l->next)
if (pupa_strcmp (name, l->mod->name) == 0)
return l->mod;
return 0;
}
void
pupa_dl_iterate (int (*hook) (pupa_dl_t mod))
{
pupa_dl_list_t l;
for (l = pupa_dl_head; l; l = l->next)
if (hook (l->mod))
break;
}
struct pupa_symbol
{
struct pupa_symbol *next;
const char *name;
void *addr;
pupa_dl_t mod; /* The module to which this symbol belongs. */
};
typedef struct pupa_symbol *pupa_symbol_t;
/* The size of the symbol table. */
#define PUPA_SYMTAB_SIZE 509
/* The symbol table (using an open-hash). */
static struct pupa_symbol *pupa_symtab[PUPA_SYMTAB_SIZE];
/* Simple hash function. */
static unsigned
pupa_symbol_hash (const char *s)
{
unsigned key = 0;
while (*s)
key = key * 65599 + *s++;
return (key + (key >> 5)) % PUPA_SYMTAB_SIZE;
}
/* Resolve the symbol name NAME and return the address.
Return NULL, if not found. */
void *
pupa_dl_resolve_symbol (const char *name)
{
pupa_symbol_t sym;
for (sym = pupa_symtab[pupa_symbol_hash (name)]; sym; sym = sym->next)
if (pupa_strcmp (sym->name, name) == 0)
return sym->addr;
return 0;
}
/* Register a symbol with the name NAME and the address ADDR. */
pupa_err_t
pupa_dl_register_symbol (const char *name, void *addr, pupa_dl_t mod)
{
pupa_symbol_t sym;
unsigned k;
sym = (pupa_symbol_t) pupa_malloc (sizeof (*sym));
if (! sym)
return pupa_errno;
if (mod)
{
sym->name = pupa_strdup (name);
if (! sym->name)
{
pupa_free (sym);
return pupa_errno;
}
}
else
sym->name = name;
sym->addr = addr;
sym->mod = mod;
k = pupa_symbol_hash (name);
sym->next = pupa_symtab[k];
pupa_symtab[k] = sym;
return PUPA_ERR_NONE;
}
/* Unregister all the symbols defined in the module MOD. */
static void
pupa_dl_unregister_symbols (pupa_dl_t mod)
{
unsigned i;
if (! mod)
pupa_fatal ("core symbols cannot be unregistered");
for (i = 0; i < PUPA_SYMTAB_SIZE; i++)
{
pupa_symbol_t sym, *p, q;
for (p = &pupa_symtab[i], sym = *p; sym; sym = q)
{
q = sym->next;
if (sym->mod == mod)
{
*p = q;
pupa_free ((void *) sym->name);
pupa_free (sym);
}
else
p = &sym->next;
}
}
}
/* Return the address of a section whose index is N. */
static void *
pupa_dl_get_section_addr (pupa_dl_t mod, unsigned n)
{
pupa_dl_segment_t seg;
for (seg = mod->segment; seg; seg = seg->next)
if (seg->section == n)
return seg->addr;
return 0;
}
/* Load all segments from memory specified by E. */
static pupa_err_t
pupa_dl_load_segments (pupa_dl_t mod, const Elf_Ehdr *e)
{
unsigned i;
Elf_Shdr *s;
for (i = 0, s = (Elf_Shdr *)((char *) e + e->e_shoff);
i < e->e_shnum;
i++, s = (Elf_Shdr *)((char *) s + e->e_shentsize))
{
if (s->sh_flags & SHF_ALLOC)
{
pupa_dl_segment_t seg;
seg = (pupa_dl_segment_t) pupa_malloc (sizeof (*seg));
if (! seg)
return pupa_errno;
if (s->sh_size)
{
void *addr;
addr = pupa_memalign (s->sh_addralign, s->sh_size);
if (! addr)
{
pupa_free (seg);
return pupa_errno;
}
switch (s->sh_type)
{
case SHT_PROGBITS:
pupa_memcpy (addr, (char *) e + s->sh_offset, s->sh_size);
break;
case SHT_NOBITS:
pupa_memset (addr, 0, s->sh_size);
break;
}
seg->addr = addr;
}
else
seg->addr = 0;
seg->size = s->sh_size;
seg->section = i;
seg->next = mod->segment;
mod->segment = seg;
}
}
return PUPA_ERR_NONE;
}
static pupa_err_t
pupa_dl_resolve_symbols (pupa_dl_t mod, Elf_Ehdr *e)
{
unsigned i;
Elf_Shdr *s;
Elf_Sym *sym;
const char *str;
Elf_Word size, entsize;
for (i = 0, s = (Elf_Shdr *) ((char *) e + e->e_shoff);
i < e->e_shnum;
i++, s = (Elf_Shdr *) ((char *) s + e->e_shentsize))
if (s->sh_type == SHT_SYMTAB)
break;
if (i == e->e_shnum)
return pupa_error (PUPA_ERR_BAD_MODULE, "no symbol table");
sym = (Elf_Sym *) ((char *) e + s->sh_offset);
size = s->sh_size;
entsize = s->sh_entsize;
s = (Elf_Shdr *) ((char *) e + e->e_shoff + e->e_shentsize * s->sh_link);
str = (char *) e + s->sh_offset;
for (i = 0;
i < size / entsize;
i++, sym = (Elf_Sym *) ((char *) sym + entsize))
{
unsigned char type = ELF_ST_TYPE (sym->st_info);
unsigned char bind = ELF_ST_BIND (sym->st_info);
const char *name = str + sym->st_name;
switch (type)
{
case STT_NOTYPE:
/* Resolve a global symbol. */
if (sym->st_name != 0 && sym->st_shndx == 0)
{
sym->st_value = (Elf_Addr) pupa_dl_resolve_symbol (name);
if (! sym->st_value)
return pupa_error (PUPA_ERR_BAD_MODULE,
"the symbol `%s' not found", name);
}
else
sym->st_value = 0;
break;
case STT_OBJECT:
sym->st_value += (Elf_Addr) pupa_dl_get_section_addr (mod,
sym->st_shndx);
if (bind != STB_LOCAL)
if (pupa_dl_register_symbol (name, (void *) sym->st_value, mod))
return pupa_errno;
break;
case STT_FUNC:
sym->st_value += (Elf_Addr) pupa_dl_get_section_addr (mod,
sym->st_shndx);
if (bind != STB_LOCAL)
if (pupa_dl_register_symbol (name, (void *) sym->st_value, mod))
return pupa_errno;
if (pupa_strcmp (name, "pupa_mod_init") == 0)
mod->init = (void (*) (pupa_dl_t)) sym->st_value;
else if (pupa_strcmp (name, "pupa_mod_fini") == 0)
mod->fini = (void (*) (void)) sym->st_value;
break;
case STT_SECTION:
sym->st_value = (Elf_Addr) pupa_dl_get_section_addr (mod,
sym->st_shndx);
break;
case STT_FILE:
sym->st_value = 0;
break;
default:
return pupa_error (PUPA_ERR_BAD_MODULE,
"unknown symbol type `%d'", (int) type);
}
}
return PUPA_ERR_NONE;
}
static void
pupa_dl_call_init (pupa_dl_t mod)
{
if (mod->init)
(mod->init) (mod);
}
static pupa_err_t
pupa_dl_resolve_name (pupa_dl_t mod, Elf_Ehdr *e)
{
Elf_Shdr *s;
const char *str;
unsigned i;
s = (Elf_Shdr *) ((char *) e + e->e_shoff + e->e_shstrndx * e->e_shentsize);
str = (char *) e + s->sh_offset;
for (i = 0, s = (Elf_Shdr *) ((char *) e + e->e_shoff);
i < e->e_shnum;
i++, s = (Elf_Shdr *) ((char *) s + e->e_shentsize))
if (pupa_strcmp (str + s->sh_name, ".modname") == 0)
{
mod->name = pupa_strdup ((char *) e + s->sh_offset);
if (! mod->name)
return pupa_errno;
break;
}
if (i == e->e_shnum)
return pupa_error (PUPA_ERR_BAD_MODULE, "no module name found");
return PUPA_ERR_NONE;
}
static pupa_err_t
pupa_dl_resolve_dependencies (pupa_dl_t mod, Elf_Ehdr *e)
{
Elf_Shdr *s;
const char *str;
unsigned i;
s = (Elf_Shdr *) ((char *) e + e->e_shoff + e->e_shstrndx * e->e_shentsize);
str = (char *) e + s->sh_offset;
for (i = 0, s = (Elf_Shdr *) ((char *) e + e->e_shoff);
i < e->e_shnum;
i++, s = (Elf_Shdr *) ((char *) s + e->e_shentsize))
if (pupa_strcmp (str + s->sh_name, ".moddeps") == 0)
{
const char *name = (char *) e + s->sh_offset;
const char *max = name + s->sh_size;
while (name < max)
{
pupa_dl_t m;
pupa_dl_dep_t dep;
m = pupa_dl_load (name);
if (! m)
return pupa_errno;
pupa_dl_ref (m);
dep = (pupa_dl_dep_t) pupa_malloc (sizeof (*dep));
if (! dep)
return pupa_errno;
dep->mod = m;
dep->next = mod->dep;
mod->dep = dep;
name += pupa_strlen (name) + 1;
}
}
return PUPA_ERR_NONE;
}
int
pupa_dl_ref (pupa_dl_t mod)
{
return ++mod->ref_count;
}
int
pupa_dl_unref (pupa_dl_t mod)
{
int ret;
ret = --mod->ref_count;
if (ret <= 0)
pupa_dl_unload (mod);
return ret;
}
/* Load a module from core memory. */
pupa_dl_t
pupa_dl_load_core (void *addr, pupa_size_t size)
{
Elf_Ehdr *e;
pupa_dl_t mod;
e = addr;
if (! pupa_arch_dl_check_header (e, size))
{
pupa_error (PUPA_ERR_BAD_MODULE, "invalid ELF header");
return 0;
}
mod = (pupa_dl_t) pupa_malloc (sizeof (*mod));
if (! mod)
return 0;
mod->name = 0;
mod->ref_count = 1;
mod->dep = 0;
mod->segment = 0;
mod->init = 0;
mod->fini = 0;
if (pupa_dl_resolve_name (mod, e)
|| pupa_dl_resolve_dependencies (mod, e)
|| pupa_dl_load_segments (mod, e)
|| pupa_dl_resolve_symbols (mod, e)
|| pupa_arch_dl_relocate_symbols (mod, e))
{
mod->fini = 0;
pupa_dl_unload (mod);
return 0;
}
pupa_dl_call_init (mod);
if (pupa_dl_add (mod))
{
pupa_dl_unload (mod);
return 0;
}
return mod;
}
/* Load a module from the file FILENAME. */
pupa_dl_t
pupa_dl_load_file (const char *filename)
{
pupa_file_t file;
pupa_ssize_t size;
void *core = 0;
pupa_dl_t mod = 0;
file = pupa_file_open (filename);
if (! file)
return 0;
size = pupa_file_size (file);
core = pupa_malloc (size);
if (! core)
goto failed;
if (pupa_file_read (file, core, size) != (int) size)
goto failed;
mod = pupa_dl_load_core (core, size);
mod->ref_count = 0;
failed:
pupa_file_close (file);
pupa_free (core);
return mod;
}
static char *pupa_dl_dir;
/* Load a module using a symbolic name. */
pupa_dl_t
pupa_dl_load (const char *name)
{
char *filename;
pupa_dl_t mod;
mod = pupa_dl_get (name);
if (mod)
return mod;
if (! pupa_dl_dir)
pupa_fatal ("module dir is not initialized yet");
filename = (char *) pupa_malloc (pupa_strlen (pupa_dl_dir) + 1
+ pupa_strlen (name) + 3);
if (! filename)
return 0;
pupa_sprintf (filename, "%s/%s.o", pupa_dl_dir, name);
mod = pupa_dl_load_file (filename);
pupa_free (filename);
if (! mod)
return 0;
if (pupa_strcmp (mod->name, name) != 0)
pupa_error (PUPA_ERR_BAD_MODULE, "mismatched names");
return mod;
}
/* Unload the module MOD. */
int
pupa_dl_unload (pupa_dl_t mod)
{
pupa_dl_dep_t dep, depn;
pupa_dl_segment_t seg, segn;
if (mod->ref_count > 0)
return 0;
if (mod->fini)
(mod->fini) ();
pupa_dl_remove (mod);
pupa_dl_unregister_symbols (mod);
for (dep = mod->dep; dep; dep = depn)
{
depn = dep->next;
pupa_dl_unref (dep->mod);
pupa_free (dep);
}
for (seg = mod->segment; seg; seg = segn)
{
segn = seg->next;
pupa_free (seg->addr);
pupa_free (seg);
}
pupa_free (mod->name);
pupa_free (mod);
return 1;
}
/* Unload unneeded modules. */
void
pupa_dl_unload_unneeded (void)
{
/* Because pupa_dl_remove modifies the list of modules, this
implementation is tricky. */
pupa_dl_list_t p = pupa_dl_head;
while (p)
{
if (pupa_dl_unload (p->mod))
{
p = pupa_dl_head;
continue;
}
p = p->next;
}
}
/* Unload all modules. */
void
pupa_dl_unload_all (void)
{
while (pupa_dl_head)
{
pupa_dl_list_t p;
pupa_dl_unload_unneeded ();
/* Force to decrement the ref count. This will purge pre-loaded
modules and manually inserted modules. */
for (p = pupa_dl_head; p; p = p->next)
p->mod->ref_count--;
}
}
void
pupa_dl_set_prefix (const char *dir)
{
pupa_dl_dir = (char *) dir;
}
const char *
pupa_dl_get_prefix (void)
{
return pupa_dl_dir;
}