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linux-next/fs/binfmt_elf_fdpic.c
Linus Torvalds 644473e9c6 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 
Pull user namespace enhancements from Eric Biederman:
 "This is a course correction for the user namespace, so that we can
  reach an inexpensive, maintainable, and reasonably complete
  implementation.

  Highlights:
   - Config guards make it impossible to enable the user namespace and
     code that has not been converted to be user namespace safe.

   - Use of the new kuid_t type ensures the if you somehow get past the
     config guards the kernel will encounter type errors if you enable
     user namespaces and attempt to compile in code whose permission
     checks have not been updated to be user namespace safe.

   - All uids from child user namespaces are mapped into the initial
     user namespace before they are processed.  Removing the need to add
     an additional check to see if the user namespace of the compared
     uids remains the same.

   - With the user namespaces compiled out the performance is as good or
     better than it is today.

   - For most operations absolutely nothing changes performance or
     operationally with the user namespace enabled.

   - The worst case performance I could come up with was timing 1
     billion cache cold stat operations with the user namespace code
     enabled.  This went from 156s to 164s on my laptop (or 156ns to
     164ns per stat operation).

   - (uid_t)-1 and (gid_t)-1 are reserved as an internal error value.
     Most uid/gid setting system calls treat these value specially
     anyway so attempting to use -1 as a uid would likely cause
     entertaining failures in userspace.

   - If setuid is called with a uid that can not be mapped setuid fails.
     I have looked at sendmail, login, ssh and every other program I
     could think of that would call setuid and they all check for and
     handle the case where setuid fails.

   - If stat or a similar system call is called from a context in which
     we can not map a uid we lie and return overflowuid.  The LFS
     experience suggests not lying and returning an error code might be
     better, but the historical precedent with uids is different and I
     can not think of anything that would break by lying about a uid we
     can't map.

   - Capabilities are localized to the current user namespace making it
     safe to give the initial user in a user namespace all capabilities.

  My git tree covers all of the modifications needed to convert the core
  kernel and enough changes to make a system bootable to runlevel 1."

Fix up trivial conflicts due to nearby independent changes in fs/stat.c

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (46 commits)
  userns:  Silence silly gcc warning.
  cred: use correct cred accessor with regards to rcu read lock
  userns: Convert the move_pages, and migrate_pages permission checks to use uid_eq
  userns: Convert cgroup permission checks to use uid_eq
  userns: Convert tmpfs to use kuid and kgid where appropriate
  userns: Convert sysfs to use kgid/kuid where appropriate
  userns: Convert sysctl permission checks to use kuid and kgids.
  userns: Convert proc to use kuid/kgid where appropriate
  userns: Convert ext4 to user kuid/kgid where appropriate
  userns: Convert ext3 to use kuid/kgid where appropriate
  userns: Convert ext2 to use kuid/kgid where appropriate.
  userns: Convert devpts to use kuid/kgid where appropriate
  userns: Convert binary formats to use kuid/kgid where appropriate
  userns: Add negative depends on entries to avoid building code that is userns unsafe
  userns: signal remove unnecessary map_cred_ns
  userns: Teach inode_capable to understand inodes whose uids map to other namespaces.
  userns: Fail exec for suid and sgid binaries with ids outside our user namespace.
  userns: Convert stat to return values mapped from kuids and kgids
  userns: Convert user specfied uids and gids in chown into kuids and kgid
  userns: Use uid_eq gid_eq helpers when comparing kuids and kgids in the vfs
  ...
2012-05-23 17:42:39 -07:00

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/* binfmt_elf_fdpic.c: FDPIC ELF binary format
*
* Copyright (C) 2003, 2004, 2006 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/pagemap.h>
#include <linux/security.h>
#include <linux/highmem.h>
#include <linux/highuid.h>
#include <linux/personality.h>
#include <linux/ptrace.h>
#include <linux/init.h>
#include <linux/elf.h>
#include <linux/elf-fdpic.h>
#include <linux/elfcore.h>
#include <linux/coredump.h>
#include <asm/uaccess.h>
#include <asm/param.h>
#include <asm/pgalloc.h>
#include <asm/exec.h>
typedef char *elf_caddr_t;
#if 0
#define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
#else
#define kdebug(fmt, ...) do {} while(0)
#endif
#if 0
#define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
#else
#define kdcore(fmt, ...) do {} while(0)
#endif
MODULE_LICENSE("GPL");
static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *);
static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
struct mm_struct *, const char *);
static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
struct elf_fdpic_params *,
struct elf_fdpic_params *);
#ifndef CONFIG_MMU
static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
unsigned long *);
static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
struct file *,
struct mm_struct *);
#endif
static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
struct file *, struct mm_struct *);
#ifdef CONFIG_ELF_CORE
static int elf_fdpic_core_dump(struct coredump_params *cprm);
#endif
static struct linux_binfmt elf_fdpic_format = {
.module = THIS_MODULE,
.load_binary = load_elf_fdpic_binary,
#ifdef CONFIG_ELF_CORE
.core_dump = elf_fdpic_core_dump,
#endif
.min_coredump = ELF_EXEC_PAGESIZE,
};
static int __init init_elf_fdpic_binfmt(void)
{
register_binfmt(&elf_fdpic_format);
return 0;
}
static void __exit exit_elf_fdpic_binfmt(void)
{
unregister_binfmt(&elf_fdpic_format);
}
core_initcall(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 (unlikely(retval != size))
return retval < 0 ? retval : -ENOEXEC;
/* 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;
}
/*****************************************************************************/
/*
* 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, entryaddr;
#ifdef ELF_FDPIC_PLAT_INIT
unsigned long dynaddr;
#endif
#ifndef CONFIG_MMU
unsigned long stack_prot;
#endif
struct file *interpreter = NULL; /* to shut gcc up */
char *interpreter_name = NULL;
int executable_stack;
int retval, i;
kdebug("____ LOAD %d ____", current->pid);
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 (unlikely(retval != phdr->p_filesz)) {
if (retval >= 0)
retval = -ENOEXEC;
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;
}
/*
* If the binary is not readable then enforce
* mm->dumpable = 0 regardless of the interpreter's
* permissions.
*/
would_dump(bprm, interpreter);
retval = kernel_read(interpreter, 0, bprm->buf,
BINPRM_BUF_SIZE);
if (unlikely(retval != BINPRM_BUF_SIZE)) {
if (retval >= 0)
retval = -ENOEXEC;
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 (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
executable_stack = EXSTACK_DEFAULT;
if (stack_size == 0) {
stack_size = interp_params.stack_size;
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);
if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
current->personality |= READ_IMPLIES_EXEC;
setup_new_exec(bprm);
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;
#ifdef CONFIG_MMU
elf_fdpic_arch_lay_out_mm(&exec_params,
&interp_params,
&current->mm->start_stack,
&current->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;
stack_prot = PROT_READ | PROT_WRITE;
if (executable_stack == EXSTACK_ENABLE_X ||
(executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
stack_prot |= PROT_EXEC;
current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
MAP_PRIVATE | MAP_ANONYMOUS |
MAP_UNINITIALIZED | MAP_GROWSDOWN,
0);
if (IS_ERR_VALUE(current->mm->start_brk)) {
retval = current->mm->start_brk;
current->mm->start_brk = 0;
goto error_kill;
}
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
install_exec_creds(bprm);
if (create_elf_fdpic_tables(bprm, current->mm,
&exec_params, &interp_params) < 0)
goto error_kill;
kdebug("- start_code %lx", current->mm->start_code);
kdebug("- end_code %lx", current->mm->end_code);
kdebug("- start_data %lx", current->mm->start_data);
kdebug("- end_data %lx", current->mm->end_data);
kdebug("- start_brk %lx", current->mm->start_brk);
kdebug("- brk %lx", current->mm->brk);
kdebug("- start_stack %lx", 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.
*/
dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
dynaddr);
#endif
/* everything is now ready... get the userspace context ready to roll */
entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
start_thread(regs, entryaddr, current->mm->start_stack);
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;
}
/*****************************************************************************/
#ifndef ELF_BASE_PLATFORM
/*
* AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
* If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
* will be copied to the user stack in the same manner as AT_PLATFORM.
*/
#define ELF_BASE_PLATFORM NULL
#endif
/*
* present useful information to the program by shovelling it onto the new
* process's stack
*/
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)
{
const struct cred *cred = current_cred();
unsigned long sp, csp, nitems;
elf_caddr_t __user *argv, *envp;
size_t platform_len = 0, len;
char *k_platform, *k_base_platform;
char __user *u_platform, *u_base_platform, *p;
long hwcap;
int loop;
int nr; /* reset for each csp adjustment */
#ifdef CONFIG_MMU
/* 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, so we give the architecture
* an opportunity to do so here.
*/
sp = arch_align_stack(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
hwcap = ELF_HWCAP;
/*
* If this architecture has a platform capability string, copy it
* to userspace. In some cases (Sparc), this info is impossible
* for userspace to get any other way, in others (i386) it is
* merely difficult.
*/
k_platform = ELF_PLATFORM;
u_platform = NULL;
if (k_platform) {
platform_len = strlen(k_platform) + 1;
sp -= platform_len;
u_platform = (char __user *) sp;
if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
return -EFAULT;
}
/*
* If this architecture has a "base" platform capability
* string, copy it to userspace.
*/
k_base_platform = ELF_BASE_PLATFORM;
u_base_platform = NULL;
if (k_base_platform) {
platform_len = strlen(k_base_platform) + 1;
sp -= platform_len;
u_base_platform = (char __user *) sp;
if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
return -EFAULT;
}
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 __user *) 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 __user *) 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 15
nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
(k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
if (bprm->interp_flags & BINPRM_FLAGS_EXECFD)
nitems++;
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(id, val) \
do { \
struct { unsigned long _id, _val; } __user *ent; \
\
ent = (void __user *) csp; \
__put_user((id), &ent[nr]._id); \
__put_user((val), &ent[nr]._val); \
nr++; \
} while (0)
nr = 0;
csp -= 2 * sizeof(unsigned long);
NEW_AUX_ENT(AT_NULL, 0);
if (k_platform) {
nr = 0;
csp -= 2 * sizeof(unsigned long);
NEW_AUX_ENT(AT_PLATFORM,
(elf_addr_t) (unsigned long) u_platform);
}
if (k_base_platform) {
nr = 0;
csp -= 2 * sizeof(unsigned long);
NEW_AUX_ENT(AT_BASE_PLATFORM,
(elf_addr_t) (unsigned long) u_base_platform);
}
if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
nr = 0;
csp -= 2 * sizeof(unsigned long);
NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
}
nr = 0;
csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
NEW_AUX_ENT(AT_HWCAP, hwcap);
NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE);
NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr);
NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum);
NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr);
NEW_AUX_ENT(AT_FLAGS, 0);
NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr);
NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
NEW_AUX_ENT(AT_EXECFN, bprm->exec);
#ifdef ARCH_DLINFO
nr = 0;
csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
/* 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 __user *) csp;
csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
argv = (elf_caddr_t __user *) csp;
/* stack argc */
csp -= sizeof(unsigned long);
__put_user(bprm->argc, (unsigned long __user *) csp);
BUG_ON(csp != sp);
/* 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 __user *) current->mm->arg_start;
for (loop = bprm->argc; loop > 0; loop--) {
__put_user((elf_caddr_t) p, argv++);
len = strnlen_user(p, MAX_ARG_STRLEN);
if (!len || len > MAX_ARG_STRLEN)
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, MAX_ARG_STRLEN);
if (!len || len > MAX_ARG_STRLEN)
return -EINVAL;
p += len;
}
__put_user(NULL, envp);
current->mm->env_end = (unsigned long) p;
mm->start_stack = (unsigned long) sp;
return 0;
}
/*****************************************************************************/
/*
* 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;
}
#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 = kzalloc(size, GFP_KERNEL);
if (!loadmap)
return -ENOMEM;
params->loadmap = loadmap;
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;
stop += 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_path.dentry->d_inode->i_ino);
return -ELIBBAD;
}
/*****************************************************************************/
/*
* 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;
maddr = vm_mmap(NULL, load_addr, top - base,
PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
if (IS_ERR_VALUE(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) {
if (clear_user((void *) (seg->addr + phdr->p_filesz),
phdr->p_memsz - phdr->p_filesz))
return -EFAULT;
}
if (mm) {
if (phdr->p_flags & PF_X) {
if (!mm->start_code) {
mm->start_code = seg->addr;
mm->end_code = seg->addr +
phdr->p_memsz;
}
} else if (!mm->start_data) {
mm->start_data = seg->addr;
mm->end_data = seg->addr + phdr->p_memsz;
}
}
seg++;
}
return 0;
}
#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;
/* create the mapping */
disp = phdr->p_vaddr & ~PAGE_MASK;
maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
phdr->p_offset - disp);
kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
loop, phdr->p_memsz + disp, prot, flags,
phdr->p_offset - disp, maddr);
if (IS_ERR_VALUE(maddr))
return (int) maddr;
if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
ELF_FDPIC_FLAG_CONTIGUOUS)
load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
seg->addr = maddr + disp;
seg->p_vaddr = phdr->p_vaddr;
seg->p_memsz = phdr->p_memsz;
/* map the ELF header address if in this segment */
if (phdr->p_offset == 0)
params->elfhdr_addr = seg->addr;
/* clear the bit between beginning of mapping and beginning of
* PT_LOAD */
if (prot & PROT_WRITE && disp > 0) {
kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
if (clear_user((void __user *) maddr, disp))
return -EFAULT;
maddr += disp;
}
/* clear any space allocated but not loaded
* - on uClinux we can just clear the lot
* - on MMU linux we'll get a SIGBUS beyond the last page
* extant in the file
*/
excess = phdr->p_memsz - phdr->p_filesz;
excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
#ifdef CONFIG_MMU
if (excess > excess1) {
unsigned long xaddr = maddr + phdr->p_filesz + excess1;
unsigned long xmaddr;
flags |= MAP_FIXED | MAP_ANONYMOUS;
xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
prot, flags, 0);
kdebug("mmap[%d] <anon>"
" ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
loop, xaddr, excess - excess1, prot, flags,
xmaddr);
if (xmaddr != xaddr)
return -ENOMEM;
}
if (prot & PROT_WRITE && excess1 > 0) {
kdebug("clear[%d] ad=%lx sz=%lx",
loop, maddr + phdr->p_filesz, excess1);
if (clear_user((void __user *) maddr + phdr->p_filesz,
excess1))
return -EFAULT;
}
#else
if (excess > 0) {
kdebug("clear[%d] ad=%lx sz=%lx",
loop, maddr + phdr->p_filesz, excess);
if (clear_user((void *) maddr + phdr->p_filesz, excess))
return -EFAULT;
}
#endif
if (mm) {
if (phdr->p_flags & PF_X) {
if (!mm->start_code) {
mm->start_code = maddr;
mm->end_code = maddr + phdr->p_memsz;
}
} else if (!mm->start_data) {
mm->start_data = maddr;
mm->end_data = maddr + phdr->p_memsz;
}
}
seg++;
}
return 0;
}
/*****************************************************************************/
/*
* ELF-FDPIC core dumper
*
* Modelled on fs/exec.c:aout_core_dump()
* Jeremy Fitzhardinge <jeremy@sw.oz.au>
*
* Modelled on fs/binfmt_elf.c core dumper
*/
#ifdef CONFIG_ELF_CORE
/*
* Decide whether a segment is worth dumping; default is yes to be
* sure (missing info is worse than too much; etc).
* Personally I'd include everything, and use the coredump limit...
*
* I think we should skip something. But I am not sure how. H.J.
*/
static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
{
int dump_ok;
/* Do not dump I/O mapped devices or special mappings */
if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
return 0;
}
/* If we may not read the contents, don't allow us to dump
* them either. "dump_write()" can't handle it anyway.
*/
if (!(vma->vm_flags & VM_READ)) {
kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
return 0;
}
/* By default, dump shared memory if mapped from an anonymous file. */
if (vma->vm_flags & VM_SHARED) {
if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) {
dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
vma->vm_flags, dump_ok ? "yes" : "no");
return dump_ok;
}
dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
vma->vm_flags, dump_ok ? "yes" : "no");
return dump_ok;
}
#ifdef CONFIG_MMU
/* By default, if it hasn't been written to, don't write it out */
if (!vma->anon_vma) {
dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
vma->vm_flags, dump_ok ? "yes" : "no");
return dump_ok;
}
#endif
dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
dump_ok ? "yes" : "no");
return dump_ok;
}
/* An ELF note in memory */
struct memelfnote
{
const char *name;
int type;
unsigned int datasz;
void *data;
};
static int notesize(struct memelfnote *en)
{
int sz;
sz = sizeof(struct elf_note);
sz += roundup(strlen(en->name) + 1, 4);
sz += roundup(en->datasz, 4);
return sz;
}
/* #define DEBUG */
#define DUMP_WRITE(addr, nr, foffset) \
do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
static int alignfile(struct file *file, loff_t *foffset)
{
static const char buf[4] = { 0, };
DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
return 1;
}
static int writenote(struct memelfnote *men, struct file *file,
loff_t *foffset)
{
struct elf_note en;
en.n_namesz = strlen(men->name) + 1;
en.n_descsz = men->datasz;
en.n_type = men->type;
DUMP_WRITE(&en, sizeof(en), foffset);
DUMP_WRITE(men->name, en.n_namesz, foffset);
if (!alignfile(file, foffset))
return 0;
DUMP_WRITE(men->data, men->datasz, foffset);
if (!alignfile(file, foffset))
return 0;
return 1;
}
#undef DUMP_WRITE
static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
{
memcpy(elf->e_ident, ELFMAG, SELFMAG);
elf->e_ident[EI_CLASS] = ELF_CLASS;
elf->e_ident[EI_DATA] = ELF_DATA;
elf->e_ident[EI_VERSION] = EV_CURRENT;
elf->e_ident[EI_OSABI] = ELF_OSABI;
memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
elf->e_type = ET_CORE;
elf->e_machine = ELF_ARCH;
elf->e_version = EV_CURRENT;
elf->e_entry = 0;
elf->e_phoff = sizeof(struct elfhdr);
elf->e_shoff = 0;
elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
elf->e_ehsize = sizeof(struct elfhdr);
elf->e_phentsize = sizeof(struct elf_phdr);
elf->e_phnum = segs;
elf->e_shentsize = 0;
elf->e_shnum = 0;
elf->e_shstrndx = 0;
return;
}
static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
{
phdr->p_type = PT_NOTE;
phdr->p_offset = offset;
phdr->p_vaddr = 0;
phdr->p_paddr = 0;
phdr->p_filesz = sz;
phdr->p_memsz = 0;
phdr->p_flags = 0;
phdr->p_align = 0;
return;
}
static inline void fill_note(struct memelfnote *note, const char *name, int type,
unsigned int sz, void *data)
{
note->name = name;
note->type = type;
note->datasz = sz;
note->data = data;
return;
}
/*
* fill up all the fields in prstatus from the given task struct, except
* registers which need to be filled up separately.
*/
static void fill_prstatus(struct elf_prstatus *prstatus,
struct task_struct *p, long signr)
{
prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
prstatus->pr_sigpend = p->pending.signal.sig[0];
prstatus->pr_sighold = p->blocked.sig[0];
rcu_read_lock();
prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
rcu_read_unlock();
prstatus->pr_pid = task_pid_vnr(p);
prstatus->pr_pgrp = task_pgrp_vnr(p);
prstatus->pr_sid = task_session_vnr(p);
if (thread_group_leader(p)) {
struct task_cputime cputime;
/*
* This is the record for the group leader. It shows the
* group-wide total, not its individual thread total.
*/
thread_group_cputime(p, &cputime);
cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
} else {
cputime_to_timeval(p->utime, &prstatus->pr_utime);
cputime_to_timeval(p->stime, &prstatus->pr_stime);
}
cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
}
static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
struct mm_struct *mm)
{
const struct cred *cred;
unsigned int i, len;
/* first copy the parameters from user space */
memset(psinfo, 0, sizeof(struct elf_prpsinfo));
len = mm->arg_end - mm->arg_start;
if (len >= ELF_PRARGSZ)
len = ELF_PRARGSZ - 1;
if (copy_from_user(&psinfo->pr_psargs,
(const char __user *) mm->arg_start, len))
return -EFAULT;
for (i = 0; i < len; i++)
if (psinfo->pr_psargs[i] == 0)
psinfo->pr_psargs[i] = ' ';
psinfo->pr_psargs[len] = 0;
rcu_read_lock();
psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
rcu_read_unlock();
psinfo->pr_pid = task_pid_vnr(p);
psinfo->pr_pgrp = task_pgrp_vnr(p);
psinfo->pr_sid = task_session_vnr(p);
i = p->state ? ffz(~p->state) + 1 : 0;
psinfo->pr_state = i;
psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
psinfo->pr_zomb = psinfo->pr_sname == 'Z';
psinfo->pr_nice = task_nice(p);
psinfo->pr_flag = p->flags;
rcu_read_lock();
cred = __task_cred(p);
SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
rcu_read_unlock();
strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
return 0;
}
/* Here is the structure in which status of each thread is captured. */
struct elf_thread_status
{
struct list_head list;
struct elf_prstatus prstatus; /* NT_PRSTATUS */
elf_fpregset_t fpu; /* NT_PRFPREG */
struct task_struct *thread;
#ifdef ELF_CORE_COPY_XFPREGS
elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
#endif
struct memelfnote notes[3];
int num_notes;
};
/*
* In order to add the specific thread information for the elf file format,
* we need to keep a linked list of every thread's pr_status and then create
* a single section for them in the final core file.
*/
static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
{
struct task_struct *p = t->thread;
int sz = 0;
t->num_notes = 0;
fill_prstatus(&t->prstatus, p, signr);
elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
&t->prstatus);
t->num_notes++;
sz += notesize(&t->notes[0]);
t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
if (t->prstatus.pr_fpvalid) {
fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
&t->fpu);
t->num_notes++;
sz += notesize(&t->notes[1]);
}
#ifdef ELF_CORE_COPY_XFPREGS
if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
sizeof(t->xfpu), &t->xfpu);
t->num_notes++;
sz += notesize(&t->notes[2]);
}
#endif
return sz;
}
static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
elf_addr_t e_shoff, int segs)
{
elf->e_shoff = e_shoff;
elf->e_shentsize = sizeof(*shdr4extnum);
elf->e_shnum = 1;
elf->e_shstrndx = SHN_UNDEF;
memset(shdr4extnum, 0, sizeof(*shdr4extnum));
shdr4extnum->sh_type = SHT_NULL;
shdr4extnum->sh_size = elf->e_shnum;
shdr4extnum->sh_link = elf->e_shstrndx;
shdr4extnum->sh_info = segs;
}
/*
* dump the segments for an MMU process
*/
#ifdef CONFIG_MMU
static int elf_fdpic_dump_segments(struct file *file, size_t *size,
unsigned long *limit, unsigned long mm_flags)
{
struct vm_area_struct *vma;
int err = 0;
for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
unsigned long addr;
if (!maydump(vma, mm_flags))
continue;
for (addr = vma->vm_start; addr < vma->vm_end;
addr += PAGE_SIZE) {
struct page *page = get_dump_page(addr);
if (page) {
void *kaddr = kmap(page);
*size += PAGE_SIZE;
if (*size > *limit)
err = -EFBIG;
else if (!dump_write(file, kaddr, PAGE_SIZE))
err = -EIO;
kunmap(page);
page_cache_release(page);
} else if (!dump_seek(file, PAGE_SIZE))
err = -EFBIG;
if (err)
goto out;
}
}
out:
return err;
}
#endif
/*
* dump the segments for a NOMMU process
*/
#ifndef CONFIG_MMU
static int elf_fdpic_dump_segments(struct file *file, size_t *size,
unsigned long *limit, unsigned long mm_flags)
{
struct vm_area_struct *vma;
for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
if (!maydump(vma, mm_flags))
continue;
if ((*size += PAGE_SIZE) > *limit)
return -EFBIG;
if (!dump_write(file, (void *) vma->vm_start,
vma->vm_end - vma->vm_start))
return -EIO;
}
return 0;
}
#endif
static size_t elf_core_vma_data_size(unsigned long mm_flags)
{
struct vm_area_struct *vma;
size_t size = 0;
for (vma = current->mm->mmap; vma; vma = vma->vm_next)
if (maydump(vma, mm_flags))
size += vma->vm_end - vma->vm_start;
return size;
}
/*
* Actual dumper
*
* This is a two-pass process; first we find the offsets of the bits,
* and then they are actually written out. If we run out of core limit
* we just truncate.
*/
static int elf_fdpic_core_dump(struct coredump_params *cprm)
{
#define NUM_NOTES 6
int has_dumped = 0;
mm_segment_t fs;
int segs;
size_t size = 0;
int i;
struct vm_area_struct *vma;
struct elfhdr *elf = NULL;
loff_t offset = 0, dataoff, foffset;
int numnote;
struct memelfnote *notes = NULL;
struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
LIST_HEAD(thread_list);
struct list_head *t;
elf_fpregset_t *fpu = NULL;
#ifdef ELF_CORE_COPY_XFPREGS
elf_fpxregset_t *xfpu = NULL;
#endif
int thread_status_size = 0;
elf_addr_t *auxv;
struct elf_phdr *phdr4note = NULL;
struct elf_shdr *shdr4extnum = NULL;
Elf_Half e_phnum;
elf_addr_t e_shoff;
/*
* We no longer stop all VM operations.
*
* This is because those proceses that could possibly change map_count
* or the mmap / vma pages are now blocked in do_exit on current
* finishing this core dump.
*
* Only ptrace can touch these memory addresses, but it doesn't change
* the map_count or the pages allocated. So no possibility of crashing
* exists while dumping the mm->vm_next areas to the core file.
*/
/* alloc memory for large data structures: too large to be on stack */
elf = kmalloc(sizeof(*elf), GFP_KERNEL);
if (!elf)
goto cleanup;
prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
if (!prstatus)
goto cleanup;
psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
if (!psinfo)
goto cleanup;
notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
if (!notes)
goto cleanup;
fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
if (!fpu)
goto cleanup;
#ifdef ELF_CORE_COPY_XFPREGS
xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
if (!xfpu)
goto cleanup;
#endif
if (cprm->signr) {
struct core_thread *ct;
struct elf_thread_status *tmp;
for (ct = current->mm->core_state->dumper.next;
ct; ct = ct->next) {
tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
if (!tmp)
goto cleanup;
tmp->thread = ct->task;
list_add(&tmp->list, &thread_list);
}
list_for_each(t, &thread_list) {
struct elf_thread_status *tmp;
int sz;
tmp = list_entry(t, struct elf_thread_status, list);
sz = elf_dump_thread_status(cprm->signr, tmp);
thread_status_size += sz;
}
}
/* now collect the dump for the current */
fill_prstatus(prstatus, current, cprm->signr);
elf_core_copy_regs(&prstatus->pr_reg, cprm->regs);
segs = current->mm->map_count;
segs += elf_core_extra_phdrs();
/* for notes section */
segs++;
/* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
* this, kernel supports extended numbering. Have a look at
* include/linux/elf.h for further information. */
e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
/* Set up header */
fill_elf_fdpic_header(elf, e_phnum);
has_dumped = 1;
current->flags |= PF_DUMPCORE;
/*
* Set up the notes in similar form to SVR4 core dumps made
* with info from their /proc.
*/
fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
fill_psinfo(psinfo, current->group_leader, current->mm);
fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
numnote = 2;
auxv = (elf_addr_t *) current->mm->saved_auxv;
i = 0;
do
i += 2;
while (auxv[i - 2] != AT_NULL);
fill_note(&notes[numnote++], "CORE", NT_AUXV,
i * sizeof(elf_addr_t), auxv);
/* Try to dump the FPU. */
if ((prstatus->pr_fpvalid =
elf_core_copy_task_fpregs(current, cprm->regs, fpu)))
fill_note(notes + numnote++,
"CORE", NT_PRFPREG, sizeof(*fpu), fpu);
#ifdef ELF_CORE_COPY_XFPREGS
if (elf_core_copy_task_xfpregs(current, xfpu))
fill_note(notes + numnote++,
"LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
#endif
fs = get_fs();
set_fs(KERNEL_DS);
offset += sizeof(*elf); /* Elf header */
offset += segs * sizeof(struct elf_phdr); /* Program headers */
foffset = offset;
/* Write notes phdr entry */
{
int sz = 0;
for (i = 0; i < numnote; i++)
sz += notesize(notes + i);
sz += thread_status_size;
phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
if (!phdr4note)
goto end_coredump;
fill_elf_note_phdr(phdr4note, sz, offset);
offset += sz;
}
/* Page-align dumped data */
dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
offset += elf_core_vma_data_size(cprm->mm_flags);
offset += elf_core_extra_data_size();
e_shoff = offset;
if (e_phnum == PN_XNUM) {
shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
if (!shdr4extnum)
goto end_coredump;
fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
}
offset = dataoff;
size += sizeof(*elf);
if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf)))
goto end_coredump;
size += sizeof(*phdr4note);
if (size > cprm->limit
|| !dump_write(cprm->file, phdr4note, sizeof(*phdr4note)))
goto end_coredump;
/* write program headers for segments dump */
for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
struct elf_phdr phdr;
size_t sz;
sz = vma->vm_end - vma->vm_start;
phdr.p_type = PT_LOAD;
phdr.p_offset = offset;
phdr.p_vaddr = vma->vm_start;
phdr.p_paddr = 0;
phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0;
phdr.p_memsz = sz;
offset += phdr.p_filesz;
phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
if (vma->vm_flags & VM_WRITE)
phdr.p_flags |= PF_W;
if (vma->vm_flags & VM_EXEC)
phdr.p_flags |= PF_X;
phdr.p_align = ELF_EXEC_PAGESIZE;
size += sizeof(phdr);
if (size > cprm->limit
|| !dump_write(cprm->file, &phdr, sizeof(phdr)))
goto end_coredump;
}
if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
goto end_coredump;
/* write out the notes section */
for (i = 0; i < numnote; i++)
if (!writenote(notes + i, cprm->file, &foffset))
goto end_coredump;
/* write out the thread status notes section */
list_for_each(t, &thread_list) {
struct elf_thread_status *tmp =
list_entry(t, struct elf_thread_status, list);
for (i = 0; i < tmp->num_notes; i++)
if (!writenote(&tmp->notes[i], cprm->file, &foffset))
goto end_coredump;
}
if (!dump_seek(cprm->file, dataoff - foffset))
goto end_coredump;
if (elf_fdpic_dump_segments(cprm->file, &size, &cprm->limit,
cprm->mm_flags) < 0)
goto end_coredump;
if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit))
goto end_coredump;
if (e_phnum == PN_XNUM) {
size += sizeof(*shdr4extnum);
if (size > cprm->limit
|| !dump_write(cprm->file, shdr4extnum,
sizeof(*shdr4extnum)))
goto end_coredump;
}
if (cprm->file->f_pos != offset) {
/* Sanity check */
printk(KERN_WARNING
"elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
cprm->file->f_pos, offset);
}
end_coredump:
set_fs(fs);
cleanup:
while (!list_empty(&thread_list)) {
struct list_head *tmp = thread_list.next;
list_del(tmp);
kfree(list_entry(tmp, struct elf_thread_status, list));
}
kfree(phdr4note);
kfree(elf);
kfree(prstatus);
kfree(psinfo);
kfree(notes);
kfree(fpu);
kfree(shdr4extnum);
#ifdef ELF_CORE_COPY_XFPREGS
kfree(xfpu);
#endif
return has_dumped;
#undef NUM_NOTES
}
#endif /* CONFIG_ELF_CORE */
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