nfsd: nfsd should drop CAP_MKNOD for non-root

[safe/jmp/linux-2.6] / fs / read_write.c

diff --git a/fs/read_write.c b/fs/read_write.c
index 969a6d9..400fe81 100644 (file)
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -50,6 +50,14 @@ generic_file_llseek_unlocked(struct file *file, loff_t offset, int origin)
                offset += inode->i_size;
                break;
        case SEEK_CUR:
+               /*
+                * Here we special-case the lseek(fd, 0, SEEK_CUR)
+                * position-querying operation.  Avoid rewriting the "same"
+                * f_pos value back to the file because a concurrent read(),
+                * write() or lseek() might have altered it
+                */
+               if (offset == 0)
+                       return file->f_pos;
                offset += file->f_pos;
                break;
        }
@@ -105,6 +113,10 @@ loff_t default_llseek(struct file *file, loff_t offset, int origin)
                        offset += i_size_read(file->f_path.dentry->d_inode);
                        break;
                case SEEK_CUR:
+                       if (offset == 0) {
+                               retval = file->f_pos;
+                               goto out;
+                       }
                        offset += file->f_pos;
        }
        retval = -EINVAL;
@@ -115,6 +127,7 @@ loff_t default_llseek(struct file *file, loff_t offset, int origin)
                }
                retval = offset;
        }
+out:
        unlock_kernel();
        return retval;
 }
@@ -134,7 +147,7 @@ loff_t vfs_llseek(struct file *file, loff_t offset, int origin)
 }
 EXPORT_SYMBOL(vfs_llseek);
 
-asmlinkage off_t sys_lseek(unsigned int fd, off_t offset, unsigned int origin)
+SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, origin)
 {
        off_t retval;
        struct file * file;
@@ -158,9 +171,9 @@ bad:
 }
 
 #ifdef __ARCH_WANT_SYS_LLSEEK
-asmlinkage long sys_llseek(unsigned int fd, unsigned long offset_high,
-                          unsigned long offset_low, loff_t __user * result,
-                          unsigned int origin)
+SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high,
+               unsigned long, offset_low, loff_t __user *, result,
+               unsigned int, origin)
 {
        int retval;
        struct file * file;
@@ -356,7 +369,7 @@ static inline void file_pos_write(struct file *file, loff_t pos)
        file->f_pos = pos;
 }
 
-asmlinkage ssize_t sys_read(unsigned int fd, char __user * buf, size_t count)
+SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count)
 {
        struct file *file;
        ssize_t ret = -EBADF;
@@ -373,7 +386,8 @@ asmlinkage ssize_t sys_read(unsigned int fd, char __user * buf, size_t count)
        return ret;
 }
 
-asmlinkage ssize_t sys_write(unsigned int fd, const char __user * buf, size_t count)
+SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf,
+               size_t, count)
 {
        struct file *file;
        ssize_t ret = -EBADF;
@@ -390,8 +404,8 @@ asmlinkage ssize_t sys_write(unsigned int fd, const char __user * buf, size_t co
        return ret;
 }
 
-asmlinkage ssize_t sys_pread64(unsigned int fd, char __user *buf,
-                            size_t count, loff_t pos)
+SYSCALL_DEFINE(pread64)(unsigned int fd, char __user *buf,
+                       size_t count, loff_t pos)
 {
        struct file *file;
        ssize_t ret = -EBADF;
@@ -410,9 +424,17 @@ asmlinkage ssize_t sys_pread64(unsigned int fd, char __user *buf,
 
        return ret;
 }
+#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
+asmlinkage long SyS_pread64(long fd, long buf, long count, loff_t pos)
+{
+       return SYSC_pread64((unsigned int) fd, (char __user *) buf,
+                           (size_t) count, pos);
+}
+SYSCALL_ALIAS(sys_pread64, SyS_pread64);
+#endif
 
-asmlinkage ssize_t sys_pwrite64(unsigned int fd, const char __user *buf,
-                             size_t count, loff_t pos)
+SYSCALL_DEFINE(pwrite64)(unsigned int fd, const char __user *buf,
+                        size_t count, loff_t pos)
 {
        struct file *file;
        ssize_t ret = -EBADF;
@@ -431,6 +453,14 @@ asmlinkage ssize_t sys_pwrite64(unsigned int fd, const char __user *buf,
 
        return ret;
 }
+#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
+asmlinkage long SyS_pwrite64(long fd, long buf, long count, loff_t pos)
+{
+       return SYSC_pwrite64((unsigned int) fd, (const char __user *) buf,
+                            (size_t) count, pos);
+}
+SYSCALL_ALIAS(sys_pwrite64, SyS_pwrite64);
+#endif
 
 /*
  * Reduce an iovec's length in-place.  Return the resulting number of segments
@@ -659,8 +689,8 @@ ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
 
 EXPORT_SYMBOL(vfs_writev);
 
-asmlinkage ssize_t
-sys_readv(unsigned long fd, const struct iovec __user *vec, unsigned long vlen)
+SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec,
+               unsigned long, vlen)
 {
        struct file *file;
        ssize_t ret = -EBADF;
@@ -680,8 +710,8 @@ sys_readv(unsigned long fd, const struct iovec __user *vec, unsigned long vlen)
        return ret;
 }
 
-asmlinkage ssize_t
-sys_writev(unsigned long fd, const struct iovec __user *vec, unsigned long vlen)
+SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec,
+               unsigned long, vlen)
 {
        struct file *file;
        ssize_t ret = -EBADF;
@@ -799,7 +829,7 @@ out:
        return retval;
 }
 
-asmlinkage ssize_t sys_sendfile(int out_fd, int in_fd, off_t __user *offset, size_t count)
+SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count)
 {
        loff_t pos;
        off_t off;
@@ -818,7 +848,7 @@ asmlinkage ssize_t sys_sendfile(int out_fd, int in_fd, off_t __user *offset, siz
        return do_sendfile(out_fd, in_fd, NULL, count, 0);
 }
 
-asmlinkage ssize_t sys_sendfile64(int out_fd, int in_fd, loff_t __user *offset, size_t count)
+SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count)
 {
        loff_t pos;
        ssize_t ret;