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linux/arch/mips/kernel/syscall.c
David Daney 098362e720 [MIPS] Add len and addr validation for MAP_FIXED mappings.
Mmap with MAP_FIXED was not validating the addr and len parameters.  This
leads to the failure of GCC's gcc.c-torture/execute/loop-2[fg].c testcases
when using the o32 ABI on a 64 bit kernel.

These testcases try to mmap 65536 bytes at 0x7fff8000 and then access all
the memory.  In 2.6.18 and 2.6.23.1 (and likely other versions as well)
the kernel maps the requested memory, but since half of it is above
0x80000000 a SIGBUS is generated when it is accessed.

This patch moves the len validation above the MAP_FIXED processing so that
it is always validated.  It also adds validation to the addr parameter for
MAP_FIXED mappings.

Signed-off-by: David Daney  <ddaney@avtrex.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-10-29 19:35:36 +00:00

450 lines
10 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1995, 1996, 1997, 2000, 2001, 05 by Ralf Baechle
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
* Copyright (C) 2001 MIPS Technologies, Inc.
*/
#include <linux/a.out.h>
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/linkage.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/smp.h>
#include <linux/mman.h>
#include <linux/ptrace.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/syscalls.h>
#include <linux/file.h>
#include <linux/slab.h>
#include <linux/utsname.h>
#include <linux/unistd.h>
#include <linux/sem.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/compiler.h>
#include <linux/module.h>
#include <linux/ipc.h>
#include <asm/branch.h>
#include <asm/cachectl.h>
#include <asm/cacheflush.h>
#include <asm/asm-offsets.h>
#include <asm/signal.h>
#include <asm/sim.h>
#include <asm/shmparam.h>
#include <asm/sysmips.h>
#include <asm/uaccess.h>
asmlinkage int sys_pipe(nabi_no_regargs volatile struct pt_regs regs)
{
int fd[2];
int error, res;
error = do_pipe(fd);
if (error) {
res = error;
goto out;
}
regs.regs[3] = fd[1];
res = fd[0];
out:
return res;
}
unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */
EXPORT_SYMBOL(shm_align_mask);
#define COLOUR_ALIGN(addr,pgoff) \
((((addr) + shm_align_mask) & ~shm_align_mask) + \
(((pgoff) << PAGE_SHIFT) & shm_align_mask))
unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
unsigned long len, unsigned long pgoff, unsigned long flags)
{
struct vm_area_struct * vmm;
int do_color_align;
unsigned long task_size;
task_size = STACK_TOP;
if (len > task_size)
return -ENOMEM;
if (flags & MAP_FIXED) {
/* Even MAP_FIXED mappings must reside within task_size. */
if (task_size - len < addr)
return -EINVAL;
/*
* We do not accept a shared mapping if it would violate
* cache aliasing constraints.
*/
if ((flags & MAP_SHARED) && (addr & shm_align_mask))
return -EINVAL;
return addr;
}
do_color_align = 0;
if (filp || (flags & MAP_SHARED))
do_color_align = 1;
if (addr) {
if (do_color_align)
addr = COLOUR_ALIGN(addr, pgoff);
else
addr = PAGE_ALIGN(addr);
vmm = find_vma(current->mm, addr);
if (task_size - len >= addr &&
(!vmm || addr + len <= vmm->vm_start))
return addr;
}
addr = TASK_UNMAPPED_BASE;
if (do_color_align)
addr = COLOUR_ALIGN(addr, pgoff);
else
addr = PAGE_ALIGN(addr);
for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
/* At this point: (!vmm || addr < vmm->vm_end). */
if (task_size - len < addr)
return -ENOMEM;
if (!vmm || addr + len <= vmm->vm_start)
return addr;
addr = vmm->vm_end;
if (do_color_align)
addr = COLOUR_ALIGN(addr, pgoff);
}
}
/* common code for old and new mmaps */
static inline unsigned long
do_mmap2(unsigned long addr, unsigned long len, unsigned long prot,
unsigned long flags, unsigned long fd, unsigned long pgoff)
{
unsigned long error = -EBADF;
struct file * file = NULL;
flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
if (!(flags & MAP_ANONYMOUS)) {
file = fget(fd);
if (!file)
goto out;
}
down_write(&current->mm->mmap_sem);
error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
up_write(&current->mm->mmap_sem);
if (file)
fput(file);
out:
return error;
}
asmlinkage unsigned long
old_mmap(unsigned long addr, unsigned long len, int prot,
int flags, int fd, off_t offset)
{
unsigned long result;
result = -EINVAL;
if (offset & ~PAGE_MASK)
goto out;
result = do_mmap2(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);
out:
return result;
}
asmlinkage unsigned long
sys_mmap2(unsigned long addr, unsigned long len, unsigned long prot,
unsigned long flags, unsigned long fd, unsigned long pgoff)
{
if (pgoff & (~PAGE_MASK >> 12))
return -EINVAL;
return do_mmap2(addr, len, prot, flags, fd, pgoff >> (PAGE_SHIFT-12));
}
save_static_function(sys_fork);
static int __used noinline
_sys_fork(nabi_no_regargs struct pt_regs regs)
{
return do_fork(SIGCHLD, regs.regs[29], &regs, 0, NULL, NULL);
}
save_static_function(sys_clone);
static int __used noinline
_sys_clone(nabi_no_regargs struct pt_regs regs)
{
unsigned long clone_flags;
unsigned long newsp;
int __user *parent_tidptr, *child_tidptr;
clone_flags = regs.regs[4];
newsp = regs.regs[5];
if (!newsp)
newsp = regs.regs[29];
parent_tidptr = (int __user *) regs.regs[6];
#ifdef CONFIG_32BIT
/* We need to fetch the fifth argument off the stack. */
child_tidptr = NULL;
if (clone_flags & (CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID)) {
int __user *__user *usp = (int __user *__user *) regs.regs[29];
if (regs.regs[2] == __NR_syscall) {
if (get_user (child_tidptr, &usp[5]))
return -EFAULT;
}
else if (get_user (child_tidptr, &usp[4]))
return -EFAULT;
}
#else
child_tidptr = (int __user *) regs.regs[8];
#endif
return do_fork(clone_flags, newsp, &regs, 0,
parent_tidptr, child_tidptr);
}
/*
* sys_execve() executes a new program.
*/
asmlinkage int sys_execve(nabi_no_regargs struct pt_regs regs)
{
int error;
char * filename;
filename = getname((char __user *) (long)regs.regs[4]);
error = PTR_ERR(filename);
if (IS_ERR(filename))
goto out;
error = do_execve(filename, (char __user *__user *) (long)regs.regs[5],
(char __user *__user *) (long)regs.regs[6], &regs);
putname(filename);
out:
return error;
}
/*
* Compacrapability ...
*/
asmlinkage int sys_uname(struct old_utsname __user * name)
{
if (name && !copy_to_user(name, utsname(), sizeof (*name)))
return 0;
return -EFAULT;
}
/*
* Compacrapability ...
*/
asmlinkage int sys_olduname(struct oldold_utsname __user * name)
{
int error;
if (!name)
return -EFAULT;
if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname)))
return -EFAULT;
error = __copy_to_user(&name->sysname, &utsname()->sysname,
__OLD_UTS_LEN);
error -= __put_user(0, name->sysname + __OLD_UTS_LEN);
error -= __copy_to_user(&name->nodename, &utsname()->nodename,
__OLD_UTS_LEN);
error -= __put_user(0, name->nodename + __OLD_UTS_LEN);
error -= __copy_to_user(&name->release, &utsname()->release,
__OLD_UTS_LEN);
error -= __put_user(0, name->release + __OLD_UTS_LEN);
error -= __copy_to_user(&name->version, &utsname()->version,
__OLD_UTS_LEN);
error -= __put_user(0, name->version + __OLD_UTS_LEN);
error -= __copy_to_user(&name->machine, &utsname()->machine,
__OLD_UTS_LEN);
error = __put_user(0, name->machine + __OLD_UTS_LEN);
error = error ? -EFAULT : 0;
return error;
}
asmlinkage int sys_set_thread_area(unsigned long addr)
{
struct thread_info *ti = task_thread_info(current);
ti->tp_value = addr;
if (cpu_has_userlocal)
write_c0_userlocal(addr);
return 0;
}
asmlinkage int _sys_sysmips(int cmd, long arg1, int arg2, int arg3)
{
switch (cmd) {
case MIPS_ATOMIC_SET:
printk(KERN_CRIT "How did I get here?\n");
return -EINVAL;
case MIPS_FIXADE:
if (arg1 & ~3)
return -EINVAL;
if (arg1 & 1)
set_thread_flag(TIF_FIXADE);
else
clear_thread_flag(TIF_FIXADE);
if (arg1 & 2)
set_thread_flag(TIF_LOGADE);
else
clear_thread_flag(TIF_FIXADE);
return 0;
case FLUSH_CACHE:
__flush_cache_all();
return 0;
}
return -EINVAL;
}
/*
* sys_ipc() is the de-multiplexer for the SysV IPC calls..
*
* This is really horribly ugly.
*/
asmlinkage int sys_ipc(unsigned int call, int first, int second,
unsigned long third, void __user *ptr, long fifth)
{
int version, ret;
version = call >> 16; /* hack for backward compatibility */
call &= 0xffff;
switch (call) {
case SEMOP:
return sys_semtimedop(first, (struct sembuf __user *)ptr,
second, NULL);
case SEMTIMEDOP:
return sys_semtimedop(first, (struct sembuf __user *)ptr,
second,
(const struct timespec __user *)fifth);
case SEMGET:
return sys_semget(first, second, third);
case SEMCTL: {
union semun fourth;
if (!ptr)
return -EINVAL;
if (get_user(fourth.__pad, (void __user *__user *) ptr))
return -EFAULT;
return sys_semctl(first, second, third, fourth);
}
case MSGSND:
return sys_msgsnd(first, (struct msgbuf __user *) ptr,
second, third);
case MSGRCV:
switch (version) {
case 0: {
struct ipc_kludge tmp;
if (!ptr)
return -EINVAL;
if (copy_from_user(&tmp,
(struct ipc_kludge __user *) ptr,
sizeof(tmp)))
return -EFAULT;
return sys_msgrcv(first, tmp.msgp, second,
tmp.msgtyp, third);
}
default:
return sys_msgrcv(first,
(struct msgbuf __user *) ptr,
second, fifth, third);
}
case MSGGET:
return sys_msgget((key_t) first, second);
case MSGCTL:
return sys_msgctl(first, second,
(struct msqid_ds __user *) ptr);
case SHMAT:
switch (version) {
default: {
unsigned long raddr;
ret = do_shmat(first, (char __user *) ptr, second,
&raddr);
if (ret)
return ret;
return put_user(raddr, (unsigned long __user *) third);
}
case 1: /* iBCS2 emulator entry point */
if (!segment_eq(get_fs(), get_ds()))
return -EINVAL;
return do_shmat(first, (char __user *) ptr, second,
(unsigned long *) third);
}
case SHMDT:
return sys_shmdt((char __user *)ptr);
case SHMGET:
return sys_shmget(first, second, third);
case SHMCTL:
return sys_shmctl(first, second,
(struct shmid_ds __user *) ptr);
default:
return -ENOSYS;
}
}
/*
* No implemented yet ...
*/
asmlinkage int sys_cachectl(char *addr, int nbytes, int op)
{
return -ENOSYS;
}
/*
* If we ever come here the user sp is bad. Zap the process right away.
* Due to the bad stack signaling wouldn't work.
*/
asmlinkage void bad_stack(void)
{
do_exit(SIGSEGV);
}
/*
* Do a system call from kernel instead of calling sys_execve so we
* end up with proper pt_regs.
*/
int kernel_execve(const char *filename, char *const argv[], char *const envp[])
{
register unsigned long __a0 asm("$4") = (unsigned long) filename;
register unsigned long __a1 asm("$5") = (unsigned long) argv;
register unsigned long __a2 asm("$6") = (unsigned long) envp;
register unsigned long __a3 asm("$7");
unsigned long __v0;
__asm__ volatile (" \n"
" .set noreorder \n"
" li $2, %5 # __NR_execve \n"
" syscall \n"
" move %0, $2 \n"
" .set reorder \n"
: "=&r" (__v0), "=r" (__a3)
: "r" (__a0), "r" (__a1), "r" (__a2), "i" (__NR_execve)
: "$2", "$8", "$9", "$10", "$11", "$12", "$13", "$14", "$15", "$24",
"memory");
if (__a3 == 0)
return __v0;
return -__v0;
}