UML/man: BLKGETSIZE takes a long, not an int

From: Nicolas George
Date: Mon Aug 13 2007 - 11:04:47 EST


Hi.

I found a type mismatch in UML that makes host block devices unusable as ubd
devices on x86_64 and other 64 bits systems (segfault of the mm subsystem):

In block/ioctl.c, the following lines show that the BLKGETSIZE ioctl expects
a pointer to a long:

case BLKGETSIZE:
if ((bdev->bd_inode->i_size >> 9) > ~0UL)
return -EFBIG;
return put_ulong(arg, bdev->bd_inode->i_size >> 9);

In arch/um/os-Linux/file.c, os_file_size calls it with an int.

The ioctl_list man page should be fixed as well.

Regards,

--
Nicolas George
diff --git a/arch/um/os-Linux/file.c b/arch/um/os-Linux/file.c
index 6f92f73..c3ecc2a 100644
--- a/arch/um/os-Linux/file.c
+++ b/arch/um/os-Linux/file.c
@@ -320,7 +320,8 @@ int os_file_size(char *file, unsigned long long *size_out)
}

if(S_ISBLK(buf.ust_mode)){
- int fd, blocks;
+ int fd;
+ long blocks;

fd = os_open_file(file, of_read(OPENFLAGS()), 0);
if(fd < 0){

Attachment: signature.asc
Description: Digital signature