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binfmt_elf_fdpic.c
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binfmt_elf_fdpic.c
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/* binfmt_elf_fdpic.c: FDPIC ELF binary format
*
* Copyright (C) 2003, 2004 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
* Derived from binfmt_elf.c
*
* 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
* 2 of the License, or (at your option) any later version.
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/stat.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/binfmts.h>
#include <linux/string.h>
#include <linux/file.h>
#include <linux/fcntl.h>
#include <linux/slab.h>
#include <linux/highmem.h>
#include <linux/personality.h>
#include <linux/ptrace.h>
#include <linux/init.h>
#include <linux/smp_lock.h>
#include <linux/elf.h>
#include <linux/elf-fdpic.h>
#include <linux/elfcore.h>
#include <asm/uaccess.h>
#include <asm/param.h>
#include <asm/pgalloc.h>
typedef char *elf_caddr_t;
#ifndef elf_addr_t
#define elf_addr_t unsigned long
#endif
#if 0
#define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
#else
#define kdebug(fmt, ...) do {} while(0)
#endif
MODULE_LICENSE("GPL");
static int load_elf_fdpic_binary(struct linux_binprm *bprm, struct pt_regs *regs);
//static int load_elf_fdpic_library(struct file *);
static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params, struct file *file);
static int elf_fdpic_map_file(struct elf_fdpic_params *params,
struct file *file,
struct mm_struct *mm,
const char *what);
static int create_elf_fdpic_tables(struct linux_binprm *bprm,
struct mm_struct *mm,
struct elf_fdpic_params *exec_params,
struct elf_fdpic_params *interp_params);
#ifndef CONFIG_MMU
static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm, unsigned long *_sp);
static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *params,
struct file *file,
struct mm_struct *mm);
#endif
static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
struct file *file,
struct mm_struct *mm);
static struct linux_binfmt elf_fdpic_format = {
.module = THIS_MODULE,
.load_binary = load_elf_fdpic_binary,
// .load_shlib = load_elf_fdpic_library,
// .core_dump = elf_fdpic_core_dump,
.min_coredump = ELF_EXEC_PAGESIZE,
};
static int __init init_elf_fdpic_binfmt(void) { return register_binfmt(&elf_fdpic_format); }
static void __exit exit_elf_fdpic_binfmt(void) { unregister_binfmt(&elf_fdpic_format); }
module_init(init_elf_fdpic_binfmt)
module_exit(exit_elf_fdpic_binfmt)
static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
{
if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
return 0;
if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
return 0;
if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
return 0;
if (!file->f_op || !file->f_op->mmap)
return 0;
return 1;
}
/*****************************************************************************/
/*
* read the program headers table into memory
*/
static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params, struct file *file)
{
struct elf32_phdr *phdr;
unsigned long size;
int retval, loop;
if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
return -ENOMEM;
if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
return -ENOMEM;
size = params->hdr.e_phnum * sizeof(struct elf_phdr);
params->phdrs = kmalloc(size, GFP_KERNEL);
if (!params->phdrs)
return -ENOMEM;
retval = kernel_read(file, params->hdr.e_phoff, (char *) params->phdrs, size);
if (retval < 0)
return retval;
/* determine stack size for this binary */
phdr = params->phdrs;
for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
if (phdr->p_type != PT_GNU_STACK)
continue;
if (phdr->p_flags & PF_X)
params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
else
params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
params->stack_size = phdr->p_memsz;
break;
}
return 0;
} /* end elf_fdpic_fetch_phdrs() */
/*****************************************************************************/
/*
* load an fdpic binary into various bits of memory
*/
static int load_elf_fdpic_binary(struct linux_binprm *bprm, struct pt_regs *regs)
{
struct elf_fdpic_params exec_params, interp_params;
struct elf_phdr *phdr;
unsigned long stack_size;
struct file *interpreter = NULL; /* to shut gcc up */
char *interpreter_name = NULL;
int executable_stack;
int retval, i;
memset(&exec_params, 0, sizeof(exec_params));
memset(&interp_params, 0, sizeof(interp_params));
exec_params.hdr = *(struct elfhdr *) bprm->buf;
exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
/* check that this is a binary we know how to deal with */
retval = -ENOEXEC;
if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
goto error;
/* read the program header table */
retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
if (retval < 0)
goto error;
/* scan for a program header that specifies an interpreter */
phdr = exec_params.phdrs;
for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
switch (phdr->p_type) {
case PT_INTERP:
retval = -ENOMEM;
if (phdr->p_filesz > PATH_MAX)
goto error;
retval = -ENOENT;
if (phdr->p_filesz < 2)
goto error;
/* read the name of the interpreter into memory */
interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
if (!interpreter_name)
goto error;
retval = kernel_read(bprm->file,
phdr->p_offset,
interpreter_name,
phdr->p_filesz);
if (retval < 0)
goto error;
retval = -ENOENT;
if (interpreter_name[phdr->p_filesz - 1] != '\0')
goto error;
kdebug("Using ELF interpreter %s", interpreter_name);
/* replace the program with the interpreter */
interpreter = open_exec(interpreter_name);
retval = PTR_ERR(interpreter);
if (IS_ERR(interpreter)) {
interpreter = NULL;
goto error;
}
retval = kernel_read(interpreter, 0, bprm->buf, BINPRM_BUF_SIZE);
if (retval < 0)
goto error;
interp_params.hdr = *((struct elfhdr *) bprm->buf);
break;
case PT_LOAD:
#ifdef CONFIG_MMU
if (exec_params.load_addr == 0)
exec_params.load_addr = phdr->p_vaddr;
#endif
break;
}
}
if (elf_check_const_displacement(&exec_params.hdr))
exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
/* perform insanity checks on the interpreter */
if (interpreter_name) {
retval = -ELIBBAD;
if (!is_elf_fdpic(&interp_params.hdr, interpreter))
goto error;
interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
/* read the interpreter's program header table */
retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
if (retval < 0)
goto error;
}
stack_size = exec_params.stack_size;
if (stack_size < interp_params.stack_size)
stack_size = interp_params.stack_size;
if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
executable_stack = EXSTACK_ENABLE_X;
else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
executable_stack = EXSTACK_DISABLE_X;
else if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
executable_stack = EXSTACK_ENABLE_X;
else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
executable_stack = EXSTACK_DISABLE_X;
else
executable_stack = EXSTACK_DEFAULT;
retval = -ENOEXEC;
if (stack_size == 0)
goto error;
if (elf_check_const_displacement(&interp_params.hdr))
interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
/* flush all traces of the currently running executable */
retval = flush_old_exec(bprm);
if (retval)
goto error;
/* there's now no turning back... the old userspace image is dead,
* defunct, deceased, etc. after this point we have to exit via
* error_kill */
set_personality(PER_LINUX_FDPIC);
set_binfmt(&elf_fdpic_format);
current->mm->start_code = 0;
current->mm->end_code = 0;
current->mm->start_stack = 0;
current->mm->start_data = 0;
current->mm->end_data = 0;
current->mm->context.exec_fdpic_loadmap = 0;
current->mm->context.interp_fdpic_loadmap = 0;
current->flags &= ~PF_FORKNOEXEC;
#ifdef CONFIG_MMU
elf_fdpic_arch_lay_out_mm(&exec_params,
&interp_params,
¤t->mm->start_stack,
¤t->mm->start_brk);
retval = setup_arg_pages(bprm, current->mm->start_stack, executable_stack);
if (retval < 0) {
send_sig(SIGKILL, current, 0);
goto error_kill;
}
#endif
/* load the executable and interpreter into memory */
retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm, "executable");
if (retval < 0)
goto error_kill;
if (interpreter_name) {
retval = elf_fdpic_map_file(&interp_params, interpreter,
current->mm, "interpreter");
if (retval < 0) {
printk(KERN_ERR "Unable to load interpreter\n");
goto error_kill;
}
allow_write_access(interpreter);
fput(interpreter);
interpreter = NULL;
}
#ifdef CONFIG_MMU
if (!current->mm->start_brk)
current->mm->start_brk = current->mm->end_data;
current->mm->brk = current->mm->start_brk = PAGE_ALIGN(current->mm->start_brk);
#else
/* create a stack and brk area big enough for everyone
* - the brk heap starts at the bottom and works up
* - the stack starts at the top and works down
*/
stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
if (stack_size < PAGE_SIZE * 2)
stack_size = PAGE_SIZE * 2;
down_write(¤t->mm->mmap_sem);
current->mm->start_brk = do_mmap(NULL,
0,
stack_size,
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_PRIVATE | MAP_ANON | MAP_GROWSDOWN,
0);
if (IS_ERR((void *) current->mm->start_brk)) {
up_write(¤t->mm->mmap_sem);
retval = current->mm->start_brk;
current->mm->start_brk = 0;
goto error_kill;
}
if (do_mremap(current->mm->start_brk,
stack_size,
ksize((char *) current->mm->start_brk),
0, 0
) == current->mm->start_brk
)
stack_size = ksize((char *) current->mm->start_brk);
up_write(¤t->mm->mmap_sem);
current->mm->brk = current->mm->start_brk;
current->mm->context.end_brk = current->mm->start_brk;
current->mm->context.end_brk += (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
current->mm->start_stack = current->mm->start_brk + stack_size;
#endif
compute_creds(bprm);
current->flags &= ~PF_FORKNOEXEC;
if (create_elf_fdpic_tables(bprm, current->mm, &exec_params, &interp_params) < 0)
goto error_kill;
kdebug("- start_code %lx", (long) current->mm->start_code);
kdebug("- end_code %lx", (long) current->mm->end_code);
kdebug("- start_data %lx", (long) current->mm->start_data);
kdebug("- end_data %lx", (long) current->mm->end_data);
kdebug("- start_brk %lx", (long) current->mm->start_brk);
kdebug("- brk %lx", (long) current->mm->brk);
kdebug("- start_stack %lx", (long) current->mm->start_stack);
#ifdef ELF_FDPIC_PLAT_INIT
/*
* The ABI may specify that certain registers be set up in special
* ways (on i386 %edx is the address of a DT_FINI function, for
* example. This macro performs whatever initialization to
* the regs structure is required.
*/
ELF_FDPIC_PLAT_INIT(regs,
exec_params.map_addr,
interp_params.map_addr,
interp_params.dynamic_addr ?: exec_params.dynamic_addr
);
#endif
/* everything is now ready... get the userspace context ready to roll */
start_thread(regs,
interp_params.entry_addr ?: exec_params.entry_addr,
current->mm->start_stack);
if (unlikely(current->ptrace & PT_PTRACED)) {
if (current->ptrace & PT_TRACE_EXEC)
ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
else
send_sig(SIGTRAP, current, 0);
}
retval = 0;
error:
if (interpreter) {
allow_write_access(interpreter);
fput(interpreter);
}
kfree(interpreter_name);
kfree(exec_params.phdrs);
kfree(exec_params.loadmap);
kfree(interp_params.phdrs);
kfree(interp_params.loadmap);
return retval;
/* unrecoverable error - kill the process */
error_kill:
send_sig(SIGSEGV, current, 0);
goto error;
} /* end load_elf_fdpic_binary() */
/*****************************************************************************/
/*
* present useful information to the program
*/
static int create_elf_fdpic_tables(struct linux_binprm *bprm,
struct mm_struct *mm,
struct elf_fdpic_params *exec_params,
struct elf_fdpic_params *interp_params)
{
unsigned long sp, csp, nitems;
elf_caddr_t *argv, *envp;
size_t platform_len = 0, len;
char *k_platform, *u_platform, *p;
long hwcap;
int loop;
/* we're going to shovel a whole load of stuff onto the stack */
#ifdef CONFIG_MMU
sp = bprm->p;
#else
sp = mm->start_stack;
/* stack the program arguments and environment */
if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
return -EFAULT;
#endif
/* get hold of platform and hardware capabilities masks for the machine
* we are running on. In some cases (Sparc), this info is impossible
* to get, in others (i386) it is merely difficult.
*/
hwcap = ELF_HWCAP;
k_platform = ELF_PLATFORM;
if (k_platform) {
platform_len = strlen(k_platform) + 1;
sp -= platform_len;
if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
return -EFAULT;
}
u_platform = (char *) sp;
#if defined(__i386__) && defined(CONFIG_SMP)
/* in some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
* by the processes running on the same package. One thing we can do
* is to shuffle the initial stack for them.
*
* the conditionals here are unneeded, but kept in to make the
* code behaviour the same as pre change unless we have hyperthreaded
* processors. This keeps Mr Marcelo Person happier but should be
* removed for 2.5
*/
if (smp_num_siblings > 1)
sp = sp - ((current->pid % 64) << 7);
#endif
sp &= ~7UL;
/* stack the load map(s) */
len = sizeof(struct elf32_fdpic_loadmap);
len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
sp = (sp - len) & ~7UL;
exec_params->map_addr = sp;
if (copy_to_user((void *) sp, exec_params->loadmap, len) != 0)
return -EFAULT;
current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
if (interp_params->loadmap) {
len = sizeof(struct elf32_fdpic_loadmap);
len += sizeof(struct elf32_fdpic_loadseg) * interp_params->loadmap->nsegs;
sp = (sp - len) & ~7UL;
interp_params->map_addr = sp;
if (copy_to_user((void *) sp, interp_params->loadmap, len) != 0)
return -EFAULT;
current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
}
/* force 16 byte _final_ alignment here for generality */
#define DLINFO_ITEMS 13
nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0);
#ifdef DLINFO_ARCH_ITEMS
nitems += DLINFO_ARCH_ITEMS;
#endif
csp = sp;
sp -= nitems * 2 * sizeof(unsigned long);
sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */
sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */
sp -= 1 * sizeof(unsigned long); /* argc */
csp -= sp & 15UL;
sp -= sp & 15UL;
/* put the ELF interpreter info on the stack */
#define NEW_AUX_ENT(nr, id, val) \
do { \
struct { unsigned long _id, _val; } *ent = (void *) csp; \
__put_user((id), &ent[nr]._id); \
__put_user((val), &ent[nr]._val); \
} while (0)
csp -= 2 * sizeof(unsigned long);
NEW_AUX_ENT(0, AT_NULL, 0);
if (k_platform) {
csp -= 2 * sizeof(unsigned long);
NEW_AUX_ENT(0, AT_PLATFORM, (elf_addr_t)(unsigned long) u_platform);
}
csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
NEW_AUX_ENT( 0, AT_HWCAP, hwcap);
NEW_AUX_ENT( 1, AT_PAGESZ, PAGE_SIZE);
NEW_AUX_ENT( 2, AT_CLKTCK, CLOCKS_PER_SEC);
NEW_AUX_ENT( 3, AT_PHDR, exec_params->ph_addr);
NEW_AUX_ENT( 4, AT_PHENT, sizeof(struct elf_phdr));
NEW_AUX_ENT( 5, AT_PHNUM, exec_params->hdr.e_phnum);
NEW_AUX_ENT( 6, AT_BASE, interp_params->elfhdr_addr);
NEW_AUX_ENT( 7, AT_FLAGS, 0);
NEW_AUX_ENT( 8, AT_ENTRY, exec_params->entry_addr);
NEW_AUX_ENT( 9, AT_UID, (elf_addr_t) current->uid);
NEW_AUX_ENT(10, AT_EUID, (elf_addr_t) current->euid);
NEW_AUX_ENT(11, AT_GID, (elf_addr_t) current->gid);
NEW_AUX_ENT(12, AT_EGID, (elf_addr_t) current->egid);
#ifdef ARCH_DLINFO
/* ARCH_DLINFO must come last so platform specific code can enforce
* special alignment requirements on the AUXV if necessary (eg. PPC).
*/
ARCH_DLINFO;
#endif
#undef NEW_AUX_ENT
/* allocate room for argv[] and envv[] */
csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
envp = (elf_caddr_t *) csp;
csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
argv = (elf_caddr_t *) csp;
/* stack argc */
csp -= sizeof(unsigned long);
__put_user(bprm->argc, (unsigned long *) csp);
if (csp != sp)
BUG();
/* fill in the argv[] array */
#ifdef CONFIG_MMU
current->mm->arg_start = bprm->p;
#else
current->mm->arg_start = current->mm->start_stack - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
#endif
p = (char *) current->mm->arg_start;
for (loop = bprm->argc; loop > 0; loop--) {
__put_user((elf_caddr_t) p, argv++);
len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES);
if (!len || len > PAGE_SIZE * MAX_ARG_PAGES)
return -EINVAL;
p += len;
}
__put_user(NULL, argv);
current->mm->arg_end = (unsigned long) p;
/* fill in the envv[] array */
current->mm->env_start = (unsigned long) p;
for (loop = bprm->envc; loop > 0; loop--) {
__put_user((elf_caddr_t)(unsigned long) p, envp++);
len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES);
if (!len || len > PAGE_SIZE * MAX_ARG_PAGES)
return -EINVAL;
p += len;
}
__put_user(NULL, envp);
current->mm->env_end = (unsigned long) p;
mm->start_stack = (unsigned long) sp;
return 0;
} /* end create_elf_fdpic_tables() */
/*****************************************************************************/
/*
* transfer the program arguments and environment from the holding pages onto
* the stack
*/
#ifndef CONFIG_MMU
static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm, unsigned long *_sp)
{
unsigned long index, stop, sp;
char *src;
int ret = 0;
stop = bprm->p >> PAGE_SHIFT;
sp = *_sp;
for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
src = kmap(bprm->page[index]);
sp -= PAGE_SIZE;
if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
ret = -EFAULT;
kunmap(bprm->page[index]);
if (ret < 0)
goto out;
}
*_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
out:
return ret;
} /* end elf_fdpic_transfer_args_to_stack() */
#endif
/*****************************************************************************/
/*
* load the appropriate binary image (executable or interpreter) into memory
* - we assume no MMU is available
* - if no other PIC bits are set in params->hdr->e_flags
* - we assume that the LOADable segments in the binary are independently relocatable
* - we assume R/O executable segments are shareable
* - else
* - we assume the loadable parts of the image to require fixed displacement
* - the image is not shareable
*/
static int elf_fdpic_map_file(struct elf_fdpic_params *params,
struct file *file,
struct mm_struct *mm,
const char *what)
{
struct elf32_fdpic_loadmap *loadmap;
#ifdef CONFIG_MMU
struct elf32_fdpic_loadseg *mseg;
#endif
struct elf32_fdpic_loadseg *seg;
struct elf32_phdr *phdr;
unsigned long load_addr, stop;
unsigned nloads, tmp;
size_t size;
int loop, ret;
/* allocate a load map table */
nloads = 0;
for (loop = 0; loop < params->hdr.e_phnum; loop++)
if (params->phdrs[loop].p_type == PT_LOAD)
nloads++;
if (nloads == 0)
return -ELIBBAD;
size = sizeof(*loadmap) + nloads * sizeof(*seg);
loadmap = kmalloc(size, GFP_KERNEL);
if (!loadmap)
return -ENOMEM;
params->loadmap = loadmap;
memset(loadmap, 0, size);
loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
loadmap->nsegs = nloads;
load_addr = params->load_addr;
seg = loadmap->segs;
/* map the requested LOADs into the memory space */
switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
case ELF_FDPIC_FLAG_CONSTDISP:
case ELF_FDPIC_FLAG_CONTIGUOUS:
#ifndef CONFIG_MMU
ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
if (ret < 0)
return ret;
break;
#endif
default:
ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
if (ret < 0)
return ret;
break;
}
/* map the entry point */
if (params->hdr.e_entry) {
seg = loadmap->segs;
for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
if (params->hdr.e_entry >= seg->p_vaddr &&
params->hdr.e_entry < seg->p_vaddr + seg->p_memsz
) {
params->entry_addr =
(params->hdr.e_entry - seg->p_vaddr) + seg->addr;
break;
}
}
}
/* determine where the program header table has wound up if mapped */
stop = params->hdr.e_phoff + params->hdr.e_phnum * sizeof (struct elf_phdr);
phdr = params->phdrs;
for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
if (phdr->p_type != PT_LOAD)
continue;
if (phdr->p_offset > params->hdr.e_phoff ||
phdr->p_offset + phdr->p_filesz < stop)
continue;
seg = loadmap->segs;
for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
if (phdr->p_vaddr >= seg->p_vaddr &&
phdr->p_vaddr + phdr->p_filesz <= seg->p_vaddr + seg->p_memsz
) {
params->ph_addr = (phdr->p_vaddr - seg->p_vaddr) + seg->addr +
params->hdr.e_phoff - phdr->p_offset;
break;
}
}
break;
}
/* determine where the dynamic section has wound up if there is one */
phdr = params->phdrs;
for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
if (phdr->p_type != PT_DYNAMIC)
continue;
seg = loadmap->segs;
for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
if (phdr->p_vaddr >= seg->p_vaddr &&
phdr->p_vaddr + phdr->p_memsz <= seg->p_vaddr + seg->p_memsz
) {
params->dynamic_addr = (phdr->p_vaddr - seg->p_vaddr) + seg->addr;
/* check the dynamic section contains at least one item, and that
* the last item is a NULL entry */
if (phdr->p_memsz == 0 ||
phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
goto dynamic_error;
tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
if (((Elf32_Dyn *) params->dynamic_addr)[tmp - 1].d_tag != 0)
goto dynamic_error;
break;
}
}
break;
}
/* now elide adjacent segments in the load map on MMU linux
* - on uClinux the holes between may actually be filled with system stuff or stuff from
* other processes
*/
#ifdef CONFIG_MMU
nloads = loadmap->nsegs;
mseg = loadmap->segs;
seg = mseg + 1;
for (loop = 1; loop < nloads; loop++) {
/* see if we have a candidate for merging */
if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
if (load_addr == (seg->addr & PAGE_MASK)) {
mseg->p_memsz += load_addr - (mseg->addr + mseg->p_memsz);
mseg->p_memsz += seg->addr & ~PAGE_MASK;
mseg->p_memsz += seg->p_memsz;
loadmap->nsegs--;
continue;
}
}
mseg++;
if (mseg != seg)
*mseg = *seg;
}
#endif
kdebug("Mapped Object [%s]:", what);
kdebug("- elfhdr : %lx", params->elfhdr_addr);
kdebug("- entry : %lx", params->entry_addr);
kdebug("- PHDR[] : %lx", params->ph_addr);
kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
seg = loadmap->segs;
for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
loop,
seg->addr, seg->addr + seg->p_memsz - 1,
seg->p_vaddr, seg->p_memsz);
return 0;
dynamic_error:
printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
what, file->f_dentry->d_inode->i_ino);
return -ELIBBAD;
} /* end elf_fdpic_map_file() */
/*****************************************************************************/
/*
* map a file with constant displacement under uClinux
*/
#ifndef CONFIG_MMU
static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *params,
struct file *file,
struct mm_struct *mm)
{
struct elf32_fdpic_loadseg *seg;
struct elf32_phdr *phdr;
unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
loff_t fpos;
int loop, ret;
load_addr = params->load_addr;
seg = params->loadmap->segs;
/* determine the bounds of the contiguous overall allocation we must make */
phdr = params->phdrs;
for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
if (params->phdrs[loop].p_type != PT_LOAD)
continue;
if (base > phdr->p_vaddr)
base = phdr->p_vaddr;
if (top < phdr->p_vaddr + phdr->p_memsz)
top = phdr->p_vaddr + phdr->p_memsz;
}
/* allocate one big anon block for everything */
mflags = MAP_PRIVATE;
if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
mflags |= MAP_EXECUTABLE;
down_write(&mm->mmap_sem);
maddr = do_mmap(NULL, load_addr, top - base,
PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
up_write(&mm->mmap_sem);
if (IS_ERR((void *) maddr))
return (int) maddr;
if (load_addr != 0)
load_addr += PAGE_ALIGN(top - base);
/* and then load the file segments into it */
phdr = params->phdrs;
for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
if (params->phdrs[loop].p_type != PT_LOAD)
continue;
fpos = phdr->p_offset;
seg->addr = maddr + (phdr->p_vaddr - base);
seg->p_vaddr = phdr->p_vaddr;
seg->p_memsz = phdr->p_memsz;
ret = file->f_op->read(file, (void *) seg->addr, phdr->p_filesz, &fpos);
if (ret < 0)
return ret;
/* map the ELF header address if in this segment */
if (phdr->p_offset == 0)
params->elfhdr_addr = seg->addr;
/* clear any space allocated but not loaded */
if (phdr->p_filesz < phdr->p_memsz)
clear_user((void *) (seg->addr + phdr->p_filesz),
phdr->p_memsz - phdr->p_filesz);
if (mm) {
if (phdr->p_flags & PF_X) {
mm->start_code = seg->addr;
mm->end_code = seg->addr + phdr->p_memsz;
}
else if (!mm->start_data) {
mm->start_data = seg->addr;
#ifndef CONFIG_MMU
mm->end_data = seg->addr + phdr->p_memsz;
#endif
}
#ifdef CONFIG_MMU
if (seg->addr + phdr->p_memsz > mm->end_data)
mm->end_data = seg->addr + phdr->p_memsz;
#endif
}
seg++;
}
return 0;
} /* end elf_fdpic_map_file_constdisp_on_uclinux() */
#endif
/*****************************************************************************/
/*
* map a binary by direct mmap() of the individual PT_LOAD segments
*/
static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
struct file *file,
struct mm_struct *mm)
{
struct elf32_fdpic_loadseg *seg;
struct elf32_phdr *phdr;
unsigned long load_addr, delta_vaddr;
int loop, dvset;
load_addr = params->load_addr;
delta_vaddr = 0;
dvset = 0;
seg = params->loadmap->segs;
/* deal with each load segment separately */
phdr = params->phdrs;
for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
unsigned long maddr, disp, excess, excess1;
int prot = 0, flags;
if (phdr->p_type != PT_LOAD)
continue;
kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
(unsigned long) phdr->p_vaddr,
(unsigned long) phdr->p_offset,
(unsigned long) phdr->p_filesz,
(unsigned long) phdr->p_memsz);
/* determine the mapping parameters */
if (phdr->p_flags & PF_R) prot |= PROT_READ;
if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
flags = MAP_PRIVATE | MAP_DENYWRITE;
if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
flags |= MAP_EXECUTABLE;
maddr = 0;
switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
case ELF_FDPIC_FLAG_INDEPENDENT:
/* PT_LOADs are independently locatable */
break;
case ELF_FDPIC_FLAG_HONOURVADDR:
/* the specified virtual address must be honoured */
maddr = phdr->p_vaddr;
flags |= MAP_FIXED;
break;
case ELF_FDPIC_FLAG_CONSTDISP:
/* constant displacement
* - can be mapped anywhere, but must be mapped as a unit
*/
if (!dvset) {
maddr = load_addr;
delta_vaddr = phdr->p_vaddr;
dvset = 1;
}
else {
maddr = load_addr + phdr->p_vaddr - delta_vaddr;
flags |= MAP_FIXED;
}
break;
case ELF_FDPIC_FLAG_CONTIGUOUS:
/* contiguity handled later */
break;
default:
BUG();
}
maddr &= PAGE_MASK;