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authorHeiko Carstens <heiko.carstens@de.ibm.com>2009-09-23 17:49:55 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2009-09-23 09:21:05 -0700
commit4fd8da8d62416d0dae05603ab5990a498d9aeb12 (patch)
tree81feb3cc66d49cfd89b0b26f067bbb52e164d0d8
parenta6e995ad7409403c5bbd6fe8f666a280e086bb22 (diff)
fs: change sys_truncate length parameter type
For this system call user space passes a signed long length parameter, while the kernel side takes an unsigned long parameter and converts it later to signed long again. This has led to bugs in compat wrappers see e.g. dd90bbd5 "powerpc: Add compat_sys_truncate". The s390 compat wrapper for this functions is broken as well since it also performs zero extension instead of sign extension for the length parameter. In addition if hpa comes up with an automated way of generating compat wrappers it would generate a wrong one here. So change the length parameter from unsigned long to long. Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/open.c5
-rw-r--r--include/linux/syscalls.h3
2 files changed, 3 insertions, 5 deletions
diff --git a/fs/open.c b/fs/open.c
index 31191bf513e..4f01e06227c 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -290,10 +290,9 @@ out:
return error;
}
-SYSCALL_DEFINE2(truncate, const char __user *, path, unsigned long, length)
+SYSCALL_DEFINE2(truncate, const char __user *, path, long, length)
{
- /* on 32-bit boxen it will cut the range 2^31--2^32-1 off */
- return do_sys_truncate(path, (long)length);
+ return do_sys_truncate(path, length);
}
static long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 8d8285a10db..a990ace1a83 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -460,8 +460,7 @@ asmlinkage long sys_mount(char __user *dev_name, char __user *dir_name,
void __user *data);
asmlinkage long sys_umount(char __user *name, int flags);
asmlinkage long sys_oldumount(char __user *name);
-asmlinkage long sys_truncate(const char __user *path,
- unsigned long length);
+asmlinkage long sys_truncate(const char __user *path, long length);
asmlinkage long sys_ftruncate(unsigned int fd, unsigned long length);
asmlinkage long sys_stat(char __user *filename,
struct __old_kernel_stat __user *statbuf);