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authorPeter Maydell <peter.maydell@linaro.org>2016-06-03 15:47:37 +0100
committerPeter Maydell <peter.maydell@linaro.org>2016-06-06 19:10:37 +0100
commitbd5692d89c448b6a9ef975f9e5c1098438689dce (patch)
tree1118efe270db7a385af7af48b0ce8604292f3c98
parent818e60ec76c77671f80827300c1eedd0b3551d1a (diff)
downloadqemu-arm-bd5692d89c448b6a9ef975f9e5c1098438689dce.tar.gz
linux-user: Use __get_user() and __put_user() to handle structs in do_fcntl()
Use the __get_user() and __put_user() to handle reading and writing the guest structures in do_ioctl(). This has two benefits: * avoids possible errors due to misaligned guest pointers * correctly sign extends signed fields (like l_start in struct flock) which might be different sizes between guest and host To do this we abstract out into copy_from/to_user functions. We also standardize on always using host flock64 and the F_GETLK64 etc flock commands, as this means we always have 64 bit offsets whether the host is 64-bit or 32-bit and we don't need to support conversion to both host struct flock and struct flock64. In passing we fix errors in converting l_type from the host to the target (where we were doing a byteswap of the host value before trying to do the convert-bitmasks operation rather than otherwise, and inexplicably shifting left by 1). Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
-rw-r--r--linux-user/syscall.c280
1 files changed, 157 insertions, 123 deletions
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 4cf67c8b44..f3a487e423 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -4894,11 +4894,11 @@ static int target_to_host_fcntl_cmd(int cmd)
case TARGET_F_SETFL:
return cmd;
case TARGET_F_GETLK:
- return F_GETLK;
- case TARGET_F_SETLK:
- return F_SETLK;
- case TARGET_F_SETLKW:
- return F_SETLKW;
+ return F_GETLK64;
+ case TARGET_F_SETLK:
+ return F_SETLK64;
+ case TARGET_F_SETLKW:
+ return F_SETLKW64;
case TARGET_F_GETOWN:
return F_GETOWN;
case TARGET_F_SETOWN:
@@ -4949,12 +4949,134 @@ static const bitmask_transtbl flock_tbl[] = {
{ 0, 0, 0, 0 }
};
-static abi_long do_fcntl(int fd, int cmd, abi_ulong arg)
+static inline abi_long copy_from_user_flock(struct flock64 *fl,
+ abi_ulong target_flock_addr)
{
- struct flock fl;
struct target_flock *target_fl;
+ short l_type;
+
+ if (!lock_user_struct(VERIFY_READ, target_fl, target_flock_addr, 1)) {
+ return -TARGET_EFAULT;
+ }
+
+ __get_user(l_type, &target_fl->l_type);
+ fl->l_type = target_to_host_bitmask(l_type, flock_tbl);
+ __get_user(fl->l_whence, &target_fl->l_whence);
+ __get_user(fl->l_start, &target_fl->l_start);
+ __get_user(fl->l_len, &target_fl->l_len);
+ __get_user(fl->l_pid, &target_fl->l_pid);
+ unlock_user_struct(target_fl, target_flock_addr, 0);
+ return 0;
+}
+
+static inline abi_long copy_to_user_flock(abi_ulong target_flock_addr,
+ const struct flock64 *fl)
+{
+ struct target_flock *target_fl;
+ short l_type;
+
+ if (!lock_user_struct(VERIFY_WRITE, target_fl, target_flock_addr, 0)) {
+ return -TARGET_EFAULT;
+ }
+
+ l_type = host_to_target_bitmask(fl->l_type, flock_tbl);
+ __put_user(l_type, &target_fl->l_type);
+ __put_user(fl->l_whence, &target_fl->l_whence);
+ __put_user(fl->l_start, &target_fl->l_start);
+ __put_user(fl->l_len, &target_fl->l_len);
+ __put_user(fl->l_pid, &target_fl->l_pid);
+ unlock_user_struct(target_fl, target_flock_addr, 1);
+ return 0;
+}
+
+typedef abi_long from_flock64_fn(struct flock64 *fl, abi_ulong target_addr);
+typedef abi_long to_flock64_fn(abi_ulong target_addr, const struct flock64 *fl);
+
+#ifdef TARGET_ARM
+static inline abi_long copy_from_user_eabi_flock64(struct flock64 *fl,
+ abi_ulong target_flock_addr)
+{
+ struct target_eabi_flock64 *target_fl;
+ short l_type;
+
+ if (!lock_user_struct(VERIFY_READ, target_fl, target_flock_addr, 1)) {
+ return -TARGET_EFAULT;
+ }
+
+ __get_user(l_type, &target_fl->l_type);
+ fl->l_type = target_to_host_bitmask(l_type, flock_tbl);
+ __get_user(fl->l_whence, &target_fl->l_whence);
+ __get_user(fl->l_start, &target_fl->l_start);
+ __get_user(fl->l_len, &target_fl->l_len);
+ __get_user(fl->l_pid, &target_fl->l_pid);
+ unlock_user_struct(target_fl, target_flock_addr, 0);
+ return 0;
+}
+
+static inline abi_long copy_to_user_eabi_flock64(abi_ulong target_flock_addr,
+ const struct flock64 *fl)
+{
+ struct target_eabi_flock64 *target_fl;
+ short l_type;
+
+ if (!lock_user_struct(VERIFY_WRITE, target_fl, target_flock_addr, 0)) {
+ return -TARGET_EFAULT;
+ }
+
+ l_type = host_to_target_bitmask(fl->l_type, flock_tbl);
+ __put_user(l_type, &target_fl->l_type);
+ __put_user(fl->l_whence, &target_fl->l_whence);
+ __put_user(fl->l_start, &target_fl->l_start);
+ __put_user(fl->l_len, &target_fl->l_len);
+ __put_user(fl->l_pid, &target_fl->l_pid);
+ unlock_user_struct(target_fl, target_flock_addr, 1);
+ return 0;
+}
+#endif
+
+static inline abi_long copy_from_user_flock64(struct flock64 *fl,
+ abi_ulong target_flock_addr)
+{
+ struct target_flock64 *target_fl;
+ short l_type;
+
+ if (!lock_user_struct(VERIFY_READ, target_fl, target_flock_addr, 1)) {
+ return -TARGET_EFAULT;
+ }
+
+ __get_user(l_type, &target_fl->l_type);
+ fl->l_type = target_to_host_bitmask(l_type, flock_tbl);
+ __get_user(fl->l_whence, &target_fl->l_whence);
+ __get_user(fl->l_start, &target_fl->l_start);
+ __get_user(fl->l_len, &target_fl->l_len);
+ __get_user(fl->l_pid, &target_fl->l_pid);
+ unlock_user_struct(target_fl, target_flock_addr, 0);
+ return 0;
+}
+
+static inline abi_long copy_to_user_flock64(abi_ulong target_flock_addr,
+ const struct flock64 *fl)
+{
+ struct target_flock64 *target_fl;
+ short l_type;
+
+ if (!lock_user_struct(VERIFY_WRITE, target_fl, target_flock_addr, 0)) {
+ return -TARGET_EFAULT;
+ }
+
+ l_type = host_to_target_bitmask(fl->l_type, flock_tbl);
+ __put_user(l_type, &target_fl->l_type);
+ __put_user(fl->l_whence, &target_fl->l_whence);
+ __put_user(fl->l_start, &target_fl->l_start);
+ __put_user(fl->l_len, &target_fl->l_len);
+ __put_user(fl->l_pid, &target_fl->l_pid);
+ unlock_user_struct(target_fl, target_flock_addr, 1);
+ return 0;
+}
+
+static abi_long do_fcntl(int fd, int cmd, abi_ulong arg)
+{
struct flock64 fl64;
- struct target_flock64 *target_fl64;
#ifdef F_GETOWN_EX
struct f_owner_ex fox;
struct target_f_owner_ex *target_fox;
@@ -4967,77 +5089,41 @@ static abi_long do_fcntl(int fd, int cmd, abi_ulong arg)
switch(cmd) {
case TARGET_F_GETLK:
- if (!lock_user_struct(VERIFY_READ, target_fl, arg, 1))
+ if (copy_from_user_flock(&fl64, arg)) {
return -TARGET_EFAULT;
- fl.l_type =
- target_to_host_bitmask(tswap16(target_fl->l_type), flock_tbl);
- fl.l_whence = tswap16(target_fl->l_whence);
- fl.l_start = tswapal(target_fl->l_start);
- fl.l_len = tswapal(target_fl->l_len);
- fl.l_pid = tswap32(target_fl->l_pid);
- unlock_user_struct(target_fl, arg, 0);
- ret = get_errno(fcntl(fd, host_cmd, &fl));
+ }
+ ret = get_errno(fcntl(fd, host_cmd, &fl64));
if (ret == 0) {
- if (!lock_user_struct(VERIFY_WRITE, target_fl, arg, 0))
+ if (copy_to_user_flock(arg, &fl64)) {
return -TARGET_EFAULT;
- target_fl->l_type =
- host_to_target_bitmask(tswap16(fl.l_type), flock_tbl);
- target_fl->l_whence = tswap16(fl.l_whence);
- target_fl->l_start = tswapal(fl.l_start);
- target_fl->l_len = tswapal(fl.l_len);
- target_fl->l_pid = tswap32(fl.l_pid);
- unlock_user_struct(target_fl, arg, 1);
+ }
}
break;
case TARGET_F_SETLK:
case TARGET_F_SETLKW:
- if (!lock_user_struct(VERIFY_READ, target_fl, arg, 1))
+ if (copy_from_user_flock(&fl64, arg)) {
return -TARGET_EFAULT;
- fl.l_type =
- target_to_host_bitmask(tswap16(target_fl->l_type), flock_tbl);
- fl.l_whence = tswap16(target_fl->l_whence);
- fl.l_start = tswapal(target_fl->l_start);
- fl.l_len = tswapal(target_fl->l_len);
- fl.l_pid = tswap32(target_fl->l_pid);
- unlock_user_struct(target_fl, arg, 0);
- ret = get_errno(fcntl(fd, host_cmd, &fl));
+ }
+ ret = get_errno(fcntl(fd, host_cmd, &fl64));
break;
case TARGET_F_GETLK64:
- if (!lock_user_struct(VERIFY_READ, target_fl64, arg, 1))
+ if (copy_from_user_flock64(&fl64, arg)) {
return -TARGET_EFAULT;
- fl64.l_type =
- target_to_host_bitmask(tswap16(target_fl64->l_type), flock_tbl) >> 1;
- fl64.l_whence = tswap16(target_fl64->l_whence);
- fl64.l_start = tswap64(target_fl64->l_start);
- fl64.l_len = tswap64(target_fl64->l_len);
- fl64.l_pid = tswap32(target_fl64->l_pid);
- unlock_user_struct(target_fl64, arg, 0);
+ }
ret = get_errno(fcntl(fd, host_cmd, &fl64));
if (ret == 0) {
- if (!lock_user_struct(VERIFY_WRITE, target_fl64, arg, 0))
+ if (copy_to_user_flock64(arg, &fl64)) {
return -TARGET_EFAULT;
- target_fl64->l_type =
- host_to_target_bitmask(tswap16(fl64.l_type), flock_tbl) >> 1;
- target_fl64->l_whence = tswap16(fl64.l_whence);
- target_fl64->l_start = tswap64(fl64.l_start);
- target_fl64->l_len = tswap64(fl64.l_len);
- target_fl64->l_pid = tswap32(fl64.l_pid);
- unlock_user_struct(target_fl64, arg, 1);
+ }
}
break;
case TARGET_F_SETLK64:
case TARGET_F_SETLKW64:
- if (!lock_user_struct(VERIFY_READ, target_fl64, arg, 1))
+ if (copy_from_user_flock64(&fl64, arg)) {
return -TARGET_EFAULT;
- fl64.l_type =
- target_to_host_bitmask(tswap16(target_fl64->l_type), flock_tbl) >> 1;
- fl64.l_whence = tswap16(target_fl64->l_whence);
- fl64.l_start = tswap64(target_fl64->l_start);
- fl64.l_len = tswap64(target_fl64->l_len);
- fl64.l_pid = tswap32(target_fl64->l_pid);
- unlock_user_struct(target_fl64, arg, 0);
+ }
ret = get_errno(fcntl(fd, host_cmd, &fl64));
break;
@@ -9485,9 +9571,14 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
{
int cmd;
struct flock64 fl;
- struct target_flock64 *target_fl;
+ from_flock64_fn *copyfrom = copy_from_user_flock64;
+ to_flock64_fn *copyto = copy_to_user_flock64;
+
#ifdef TARGET_ARM
- struct target_eabi_flock64 *target_efl;
+ if (((CPUARMState *)cpu_env)->eabi) {
+ copyfrom = copy_from_user_eabi_flock64;
+ copyto = copy_to_user_eabi_flock64;
+ }
#endif
cmd = target_to_host_fcntl_cmd(arg2);
@@ -9498,78 +9589,21 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
switch(arg2) {
case TARGET_F_GETLK64:
-#ifdef TARGET_ARM
- if (((CPUARMState *)cpu_env)->eabi) {
- if (!lock_user_struct(VERIFY_READ, target_efl, arg3, 1))
- goto efault;
- fl.l_type = tswap16(target_efl->l_type);
- fl.l_whence = tswap16(target_efl->l_whence);
- fl.l_start = tswap64(target_efl->l_start);
- fl.l_len = tswap64(target_efl->l_len);
- fl.l_pid = tswap32(target_efl->l_pid);
- unlock_user_struct(target_efl, arg3, 0);
- } else
-#endif
- {
- if (!lock_user_struct(VERIFY_READ, target_fl, arg3, 1))
- goto efault;
- fl.l_type = tswap16(target_fl->l_type);
- fl.l_whence = tswap16(target_fl->l_whence);
- fl.l_start = tswap64(target_fl->l_start);
- fl.l_len = tswap64(target_fl->l_len);
- fl.l_pid = tswap32(target_fl->l_pid);
- unlock_user_struct(target_fl, arg3, 0);
+ if (copyfrom(&fl, arg3)) {
+ goto efault;
}
ret = get_errno(fcntl(arg1, cmd, &fl));
if (ret == 0) {
-#ifdef TARGET_ARM
- if (((CPUARMState *)cpu_env)->eabi) {
- if (!lock_user_struct(VERIFY_WRITE, target_efl, arg3, 0))
- goto efault;
- target_efl->l_type = tswap16(fl.l_type);
- target_efl->l_whence = tswap16(fl.l_whence);
- target_efl->l_start = tswap64(fl.l_start);
- target_efl->l_len = tswap64(fl.l_len);
- target_efl->l_pid = tswap32(fl.l_pid);
- unlock_user_struct(target_efl, arg3, 1);
- } else
-#endif
- {
- if (!lock_user_struct(VERIFY_WRITE, target_fl, arg3, 0))
- goto efault;
- target_fl->l_type = tswap16(fl.l_type);
- target_fl->l_whence = tswap16(fl.l_whence);
- target_fl->l_start = tswap64(fl.l_start);
- target_fl->l_len = tswap64(fl.l_len);
- target_fl->l_pid = tswap32(fl.l_pid);
- unlock_user_struct(target_fl, arg3, 1);
+ if (copyto(arg3, &fl)) {
+ goto efault;
}
}
break;
case TARGET_F_SETLK64:
case TARGET_F_SETLKW64:
-#ifdef TARGET_ARM
- if (((CPUARMState *)cpu_env)->eabi) {
- if (!lock_user_struct(VERIFY_READ, target_efl, arg3, 1))
- goto efault;
- fl.l_type = tswap16(target_efl->l_type);
- fl.l_whence = tswap16(target_efl->l_whence);
- fl.l_start = tswap64(target_efl->l_start);
- fl.l_len = tswap64(target_efl->l_len);
- fl.l_pid = tswap32(target_efl->l_pid);
- unlock_user_struct(target_efl, arg3, 0);
- } else
-#endif
- {
- if (!lock_user_struct(VERIFY_READ, target_fl, arg3, 1))
- goto efault;
- fl.l_type = tswap16(target_fl->l_type);
- fl.l_whence = tswap16(target_fl->l_whence);
- fl.l_start = tswap64(target_fl->l_start);
- fl.l_len = tswap64(target_fl->l_len);
- fl.l_pid = tswap32(target_fl->l_pid);
- unlock_user_struct(target_fl, arg3, 0);
+ if (copyfrom(&fl, arg3)) {
+ goto efault;
}
ret = get_errno(fcntl(arg1, cmd, &fl));
break;