Mark arguments to certain syscalls as being const

Mark arguments to certain system calls as being const where they should be but
aren't.  The list includes:

 (*) The filename arguments of various stat syscalls, execve(), various utimes
     syscalls and some mount syscalls.

 (*) The filename arguments of some syscall helpers relating to the above.

 (*) The buffer argument of various write syscalls.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 35 insertions, 24 deletions

diff --git a/fs/compat.c b/fs/compat.c
index e6d5d70cf3c..718c7062aec 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -77,7 +77,8 @@ int compat_printk(const char *fmt, ...)
  * Not all architectures have sys_utime, so implement this in terms
  * of sys_utimes.
  */
-asmlinkage long compat_sys_utime(char __user *filename, struct compat_utimbuf __user *t)
+asmlinkage long compat_sys_utime(const char __user *filename,
+                                 struct compat_utimbuf __user *t)
 {
         struct timespec tv[2];
 
@@ -91,7 +92,7 @@ asmlinkage long compat_sys_utime(char __user *filename, struct compat_utimbuf __
         return do_utimes(AT_FDCWD, filename, t ? tv : NULL, 0);
 }
 
-asmlinkage long compat_sys_utimensat(unsigned int dfd, char __user *filename, struct compat_timespec __user *t, int flags)
+asmlinkage long compat_sys_utimensat(unsigned int dfd, const char __user *filename, struct compat_timespec __user *t, int flags)
 {
         struct timespec tv[2];
 
@@ -106,7 +107,7 @@ asmlinkage long compat_sys_utimensat(unsigned int dfd, char __user *filename, st
         return do_utimes(dfd, filename, t ? tv : NULL, flags);
 }
 
-asmlinkage long compat_sys_futimesat(unsigned int dfd, char __user *filename, struct compat_timeval __user *t)
+asmlinkage long compat_sys_futimesat(unsigned int dfd, const char __user *filename, struct compat_timeval __user *t)
 {
         struct timespec tv[2];
 
@@ -125,7 +126,7 @@ asmlinkage long compat_sys_futimesat(unsigned int dfd, char __user *filename, st
         return do_utimes(dfd, filename, t ? tv : NULL, 0);
 }
 
-asmlinkage long compat_sys_utimes(char __user *filename, struct compat_timeval __user *t)
+asmlinkage long compat_sys_utimes(const char __user *filename, struct compat_timeval __user *t)
 {
         return compat_sys_futimesat(AT_FDCWD, filename, t);
 }
@@ -169,7 +170,7 @@ static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf)
         return err;
 }
 
-asmlinkage long compat_sys_newstat(char __user * filename,
+asmlinkage long compat_sys_newstat(const char __user * filename,
                 struct compat_stat __user *statbuf)
 {
         struct kstat stat;
@@ -181,7 +182,7 @@ asmlinkage long compat_sys_newstat(char __user * filename,
         return cp_compat_stat(&stat, statbuf);
 }
 
-asmlinkage long compat_sys_newlstat(char __user * filename,
+asmlinkage long compat_sys_newlstat(const char __user * filename,
                 struct compat_stat __user *statbuf)
 {
         struct kstat stat;
@@ -194,7 +195,8 @@ asmlinkage long compat_sys_newlstat(char __user * filename,
 }
 
 #ifndef __ARCH_WANT_STAT64
-asmlinkage long compat_sys_newfstatat(unsigned int dfd, char __user *filename,
+asmlinkage long compat_sys_newfstatat(unsigned int dfd,
+                const char __user *filename,
                 struct compat_stat __user *statbuf, int flag)
 {
         struct kstat stat;
@@ -837,9 +839,10 @@ static int do_nfs4_super_data_conv(void *raw_data)
 #define NCPFS_NAME      "ncpfs"
 #define NFS4_NAME       "nfs4"
 
-asmlinkage long compat_sys_mount(char __user * dev_name, char __user * dir_name,
-                                 char __user * type, unsigned long flags,
-                                 void __user * data)
+asmlinkage long compat_sys_mount(const char __user * dev_name,
+                                 const char __user * dir_name,
+                                 const char __user * type, unsigned long flags,
+                                 const void __user * data)
 {
         char *kernel_type;
         unsigned long data_page;
diff --git a/fs/stat.c b/fs/stat.c
index c4ecd52c573..12e90e21390 100644
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -68,7 +68,8 @@ int vfs_fstat(unsigned int fd, struct kstat *stat)
 }
 EXPORT_SYMBOL(vfs_fstat);
 
-int vfs_fstatat(int dfd, char __user *filename, struct kstat *stat, int flag)
+int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat,
+                int flag)
 {
         struct path path;
         int error = -EINVAL;
@@ -91,13 +92,13 @@ out:
 }
 EXPORT_SYMBOL(vfs_fstatat);
 
-int vfs_stat(char __user *name, struct kstat *stat)
+int vfs_stat(const char __user *name, struct kstat *stat)
 {
         return vfs_fstatat(AT_FDCWD, name, stat, 0);
 }
 EXPORT_SYMBOL(vfs_stat);
 
-int vfs_lstat(char __user *name, struct kstat *stat)
+int vfs_lstat(const char __user *name, struct kstat *stat)
 {
         return vfs_fstatat(AT_FDCWD, name, stat, AT_SYMLINK_NOFOLLOW);
 }
@@ -147,7 +148,8 @@ static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * sta
         return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
 }
 
-SYSCALL_DEFINE2(stat, char __user *, filename, struct __old_kernel_stat __user *, statbuf)
+SYSCALL_DEFINE2(stat, const char __user *, filename,
+                struct __old_kernel_stat __user *, statbuf)
 {
         struct kstat stat;
         int error;
@@ -159,7 +161,8 @@ SYSCALL_DEFINE2(stat, char __user *, filename, struct __old_kernel_stat __user *
         return cp_old_stat(&stat, statbuf);
 }
 
-SYSCALL_DEFINE2(lstat, char __user *, filename, struct __old_kernel_stat __user *, statbuf)
+SYSCALL_DEFINE2(lstat, const char __user *, filename,
+                struct __old_kernel_stat __user *, statbuf)
 {
         struct kstat stat;
         int error;
@@ -234,7 +237,8 @@ static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
         return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
 }
 
-SYSCALL_DEFINE2(newstat, char __user *, filename, struct stat __user *, statbuf)
+SYSCALL_DEFINE2(newstat, const char __user *, filename,
+                struct stat __user *, statbuf)
 {
         struct kstat stat;
         int error = vfs_stat(filename, &stat);
@@ -244,7 +248,8 @@ SYSCALL_DEFINE2(newstat, char __user *, filename, struct stat __user *, statbuf)
         return cp_new_stat(&stat, statbuf);
 }
 
-SYSCALL_DEFINE2(newlstat, char __user *, filename, struct stat __user *, statbuf)
+SYSCALL_DEFINE2(newlstat, const char __user *, filename,
+                struct stat __user *, statbuf)
 {
         struct kstat stat;
         int error;
@@ -257,7 +262,7 @@ SYSCALL_DEFINE2(newlstat, char __user *, filename, struct stat __user *, statbuf
 }
 
 #if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
-SYSCALL_DEFINE4(newfstatat, int, dfd, char __user *, filename,
+SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
                 struct stat __user *, statbuf, int, flag)
 {
         struct kstat stat;
@@ -355,7 +360,8 @@ static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
         return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
 }
 
-SYSCALL_DEFINE2(stat64, char __user *, filename, struct stat64 __user *, statbuf)
+SYSCALL_DEFINE2(stat64, const char __user *, filename,
+                struct stat64 __user *, statbuf)
 {
         struct kstat stat;
         int error = vfs_stat(filename, &stat);
@@ -366,7 +372,8 @@ SYSCALL_DEFINE2(stat64, char __user *, filename, struct stat64 __user *, statbuf
         return error;
 }
 
-SYSCALL_DEFINE2(lstat64, char __user *, filename, struct stat64 __user *, statbuf)
+SYSCALL_DEFINE2(lstat64, const char __user *, filename,
+                struct stat64 __user *, statbuf)
 {
         struct kstat stat;
         int error = vfs_lstat(filename, &stat);
@@ -388,7 +395,7 @@ SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf)
         return error;
 }
 
-SYSCALL_DEFINE4(fstatat64, int, dfd, char __user *, filename,
+SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
                 struct stat64 __user *, statbuf, int, flag)
 {
         struct kstat stat;
diff --git a/fs/utimes.c b/fs/utimes.c
index e4c75db5d37..179b5869065 100644
--- a/fs/utimes.c
+++ b/fs/utimes.c
@@ -126,7 +126,8 @@ out:
  * must be owner or have write permission.
  * Else, update from *times, must be owner or super user.
  */
-long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags)
+long do_utimes(int dfd, const char __user *filename, struct timespec *times,
+               int flags)
 {
         int error = -EINVAL;
 
@@ -170,7 +171,7 @@ out:
         return error;
 }
 
-SYSCALL_DEFINE4(utimensat, int, dfd, char __user *, filename,
+SYSCALL_DEFINE4(utimensat, int, dfd, const char __user *, filename,
                 struct timespec __user *, utimes, int, flags)
 {
         struct timespec tstimes[2];
@@ -188,7 +189,7 @@ SYSCALL_DEFINE4(utimensat, int, dfd, char __user *, filename,
         return do_utimes(dfd, filename, utimes ? tstimes : NULL, flags);
 }
 
-SYSCALL_DEFINE3(futimesat, int, dfd, char __user *, filename,
+SYSCALL_DEFINE3(futimesat, int, dfd, const char __user *, filename,
                 struct timeval __user *, utimes)
 {
         struct timeval times[2];