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fcntl: move compat syscalls from compat.c
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Al Viro committed Apr 17, 2017
1 parent 0460b2a commit 80f0cce
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Showing 2 changed files with 157 additions and 154 deletions.
154 changes: 0 additions & 154 deletions fs/compat.c
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Original file line number Diff line number Diff line change
Expand Up @@ -137,160 +137,6 @@ COMPAT_SYSCALL_DEFINE2(newfstat, unsigned int, fd,
return error;
}

static int get_compat_flock(struct flock *kfl, struct compat_flock __user *ufl)
{
if (!access_ok(VERIFY_READ, ufl, sizeof(*ufl)) ||
__get_user(kfl->l_type, &ufl->l_type) ||
__get_user(kfl->l_whence, &ufl->l_whence) ||
__get_user(kfl->l_start, &ufl->l_start) ||
__get_user(kfl->l_len, &ufl->l_len) ||
__get_user(kfl->l_pid, &ufl->l_pid))
return -EFAULT;
return 0;
}

static int put_compat_flock(struct flock *kfl, struct compat_flock __user *ufl)
{
if (!access_ok(VERIFY_WRITE, ufl, sizeof(*ufl)) ||
__put_user(kfl->l_type, &ufl->l_type) ||
__put_user(kfl->l_whence, &ufl->l_whence) ||
__put_user(kfl->l_start, &ufl->l_start) ||
__put_user(kfl->l_len, &ufl->l_len) ||
__put_user(kfl->l_pid, &ufl->l_pid))
return -EFAULT;
return 0;
}

#ifndef HAVE_ARCH_GET_COMPAT_FLOCK64
static int get_compat_flock64(struct flock *kfl, struct compat_flock64 __user *ufl)
{
if (!access_ok(VERIFY_READ, ufl, sizeof(*ufl)) ||
__get_user(kfl->l_type, &ufl->l_type) ||
__get_user(kfl->l_whence, &ufl->l_whence) ||
__get_user(kfl->l_start, &ufl->l_start) ||
__get_user(kfl->l_len, &ufl->l_len) ||
__get_user(kfl->l_pid, &ufl->l_pid))
return -EFAULT;
return 0;
}
#endif

#ifndef HAVE_ARCH_PUT_COMPAT_FLOCK64
static int put_compat_flock64(struct flock *kfl, struct compat_flock64 __user *ufl)
{
if (!access_ok(VERIFY_WRITE, ufl, sizeof(*ufl)) ||
__put_user(kfl->l_type, &ufl->l_type) ||
__put_user(kfl->l_whence, &ufl->l_whence) ||
__put_user(kfl->l_start, &ufl->l_start) ||
__put_user(kfl->l_len, &ufl->l_len) ||
__put_user(kfl->l_pid, &ufl->l_pid))
return -EFAULT;
return 0;
}
#endif

static unsigned int
convert_fcntl_cmd(unsigned int cmd)
{
switch (cmd) {
case F_GETLK64:
return F_GETLK;
case F_SETLK64:
return F_SETLK;
case F_SETLKW64:
return F_SETLKW;
}

return cmd;
}

COMPAT_SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd,
compat_ulong_t, arg)
{
mm_segment_t old_fs;
struct flock f;
long ret;
unsigned int conv_cmd;

switch (cmd) {
case F_GETLK:
case F_SETLK:
case F_SETLKW:
ret = get_compat_flock(&f, compat_ptr(arg));
if (ret != 0)
break;
old_fs = get_fs();
set_fs(KERNEL_DS);
ret = sys_fcntl(fd, cmd, (unsigned long)&f);
set_fs(old_fs);
if (cmd == F_GETLK && ret == 0) {
/* GETLK was successful and we need to return the data...
* but it needs to fit in the compat structure.
* l_start shouldn't be too big, unless the original
* start + end is greater than COMPAT_OFF_T_MAX, in which
* case the app was asking for trouble, so we return
* -EOVERFLOW in that case.
* l_len could be too big, in which case we just truncate it,
* and only allow the app to see that part of the conflicting
* lock that might make sense to it anyway
*/

if (f.l_start > COMPAT_OFF_T_MAX)
ret = -EOVERFLOW;
if (f.l_len > COMPAT_OFF_T_MAX)
f.l_len = COMPAT_OFF_T_MAX;
if (ret == 0)
ret = put_compat_flock(&f, compat_ptr(arg));
}
break;

case F_GETLK64:
case F_SETLK64:
case F_SETLKW64:
case F_OFD_GETLK:
case F_OFD_SETLK:
case F_OFD_SETLKW:
ret = get_compat_flock64(&f, compat_ptr(arg));
if (ret != 0)
break;
old_fs = get_fs();
set_fs(KERNEL_DS);
conv_cmd = convert_fcntl_cmd(cmd);
ret = sys_fcntl(fd, conv_cmd, (unsigned long)&f);
set_fs(old_fs);
if ((conv_cmd == F_GETLK || conv_cmd == F_OFD_GETLK) && ret == 0) {
/* need to return lock information - see above for commentary */
if (f.l_start > COMPAT_LOFF_T_MAX)
ret = -EOVERFLOW;
if (f.l_len > COMPAT_LOFF_T_MAX)
f.l_len = COMPAT_LOFF_T_MAX;
if (ret == 0)
ret = put_compat_flock64(&f, compat_ptr(arg));
}
break;

default:
ret = sys_fcntl(fd, cmd, arg);
break;
}
return ret;
}

COMPAT_SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd,
compat_ulong_t, arg)
{
switch (cmd) {
case F_GETLK64:
case F_SETLK64:
case F_SETLKW64:
case F_OFD_GETLK:
case F_OFD_SETLK:
case F_OFD_SETLKW:
return -EINVAL;
}
return compat_sys_fcntl64(fd, cmd, arg);
}

/* A write operation does a read from user space and vice versa */
#define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ)

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157 changes: 157 additions & 0 deletions fs/fcntl.c
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Original file line number Diff line number Diff line change
Expand Up @@ -23,6 +23,7 @@
#include <linux/pid_namespace.h>
#include <linux/user_namespace.h>
#include <linux/shmem_fs.h>
#include <linux/compat.h>

#include <asm/poll.h>
#include <asm/siginfo.h>
Expand Down Expand Up @@ -420,6 +421,162 @@ SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd,
}
#endif

#ifdef CONFIG_COMPAT
static int get_compat_flock(struct flock *kfl, struct compat_flock __user *ufl)
{
if (!access_ok(VERIFY_READ, ufl, sizeof(*ufl)) ||
__get_user(kfl->l_type, &ufl->l_type) ||
__get_user(kfl->l_whence, &ufl->l_whence) ||
__get_user(kfl->l_start, &ufl->l_start) ||
__get_user(kfl->l_len, &ufl->l_len) ||
__get_user(kfl->l_pid, &ufl->l_pid))
return -EFAULT;
return 0;
}

static int put_compat_flock(struct flock *kfl, struct compat_flock __user *ufl)
{
if (!access_ok(VERIFY_WRITE, ufl, sizeof(*ufl)) ||
__put_user(kfl->l_type, &ufl->l_type) ||
__put_user(kfl->l_whence, &ufl->l_whence) ||
__put_user(kfl->l_start, &ufl->l_start) ||
__put_user(kfl->l_len, &ufl->l_len) ||
__put_user(kfl->l_pid, &ufl->l_pid))
return -EFAULT;
return 0;
}

#ifndef HAVE_ARCH_GET_COMPAT_FLOCK64
static int get_compat_flock64(struct flock *kfl, struct compat_flock64 __user *ufl)
{
if (!access_ok(VERIFY_READ, ufl, sizeof(*ufl)) ||
__get_user(kfl->l_type, &ufl->l_type) ||
__get_user(kfl->l_whence, &ufl->l_whence) ||
__get_user(kfl->l_start, &ufl->l_start) ||
__get_user(kfl->l_len, &ufl->l_len) ||
__get_user(kfl->l_pid, &ufl->l_pid))
return -EFAULT;
return 0;
}
#endif

#ifndef HAVE_ARCH_PUT_COMPAT_FLOCK64
static int put_compat_flock64(struct flock *kfl, struct compat_flock64 __user *ufl)
{
if (!access_ok(VERIFY_WRITE, ufl, sizeof(*ufl)) ||
__put_user(kfl->l_type, &ufl->l_type) ||
__put_user(kfl->l_whence, &ufl->l_whence) ||
__put_user(kfl->l_start, &ufl->l_start) ||
__put_user(kfl->l_len, &ufl->l_len) ||
__put_user(kfl->l_pid, &ufl->l_pid))
return -EFAULT;
return 0;
}
#endif

static unsigned int
convert_fcntl_cmd(unsigned int cmd)
{
switch (cmd) {
case F_GETLK64:
return F_GETLK;
case F_SETLK64:
return F_SETLK;
case F_SETLKW64:
return F_SETLKW;
}

return cmd;
}

COMPAT_SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd,
compat_ulong_t, arg)
{
mm_segment_t old_fs;
struct flock f;
long ret;
unsigned int conv_cmd;

switch (cmd) {
case F_GETLK:
case F_SETLK:
case F_SETLKW:
ret = get_compat_flock(&f, compat_ptr(arg));
if (ret != 0)
break;
old_fs = get_fs();
set_fs(KERNEL_DS);
ret = sys_fcntl(fd, cmd, (unsigned long)&f);
set_fs(old_fs);
if (cmd == F_GETLK && ret == 0) {
/* GETLK was successful and we need to return the data...
* but it needs to fit in the compat structure.
* l_start shouldn't be too big, unless the original
* start + end is greater than COMPAT_OFF_T_MAX, in which
* case the app was asking for trouble, so we return
* -EOVERFLOW in that case.
* l_len could be too big, in which case we just truncate it,
* and only allow the app to see that part of the conflicting
* lock that might make sense to it anyway
*/

if (f.l_start > COMPAT_OFF_T_MAX)
ret = -EOVERFLOW;
if (f.l_len > COMPAT_OFF_T_MAX)
f.l_len = COMPAT_OFF_T_MAX;
if (ret == 0)
ret = put_compat_flock(&f, compat_ptr(arg));
}
break;

case F_GETLK64:
case F_SETLK64:
case F_SETLKW64:
case F_OFD_GETLK:
case F_OFD_SETLK:
case F_OFD_SETLKW:
ret = get_compat_flock64(&f, compat_ptr(arg));
if (ret != 0)
break;
old_fs = get_fs();
set_fs(KERNEL_DS);
conv_cmd = convert_fcntl_cmd(cmd);
ret = sys_fcntl(fd, conv_cmd, (unsigned long)&f);
set_fs(old_fs);
if ((conv_cmd == F_GETLK || conv_cmd == F_OFD_GETLK) && ret == 0) {
/* need to return lock information - see above for commentary */
if (f.l_start > COMPAT_LOFF_T_MAX)
ret = -EOVERFLOW;
if (f.l_len > COMPAT_LOFF_T_MAX)
f.l_len = COMPAT_LOFF_T_MAX;
if (ret == 0)
ret = put_compat_flock64(&f, compat_ptr(arg));
}
break;

default:
ret = sys_fcntl(fd, cmd, arg);
break;
}
return ret;
}

COMPAT_SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd,
compat_ulong_t, arg)
{
switch (cmd) {
case F_GETLK64:
case F_SETLK64:
case F_SETLKW64:
case F_OFD_GETLK:
case F_OFD_SETLK:
case F_OFD_SETLKW:
return -EINVAL;
}
return compat_sys_fcntl64(fd, cmd, arg);
}
#endif

/* Table to convert sigio signal codes into poll band bitmaps */

static const long band_table[NSIGPOLL] = {
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