fs/compat: fix parameter handling for compat readv/writev syscalls

heicarst · torvalds · commit dfd948e32af2 · 2014-01-29T16:22:39.000-08:00
We got a report that the pwritev syscall does not work correctly in compat mode on s390. It turned out that with commit 72ec351 ("switch compat readv/writev variants to COMPAT_SYSCALL_DEFINE") we lost the zero extension of a couple of syscall parameters because the some parameter types haven't been converted from unsigned long to compat_ulong_t. This is needed for architectures where the ABI requires that the caller of a function performed zero and/or sign extension to 64 bit of all parameters. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Ingo Molnar <mingo@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: <stable@vger.kernel.org> [v3.10+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/read_write.c b/fs/read_write.c
@@ -964,9 +964,9 @@ static size_t compat_readv(struct file *file,
 	return ret;
 }
 
-COMPAT_SYSCALL_DEFINE3(readv, unsigned long, fd,
+COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd,
 		const struct compat_iovec __user *,vec,
-		unsigned long, vlen)
+		compat_ulong_t, vlen)
 {
 	struct fd f = fdget(fd);
 	ssize_t ret;
@@ -1001,9 +1001,9 @@ COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd,
 	return ret;
 }
 
-COMPAT_SYSCALL_DEFINE5(preadv, unsigned long, fd,
+COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd,
 		const struct compat_iovec __user *,vec,
-		unsigned long, vlen, u32, pos_low, u32, pos_high)
+		compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
 {
 	loff_t pos = ((loff_t)pos_high << 32) | pos_low;
 	return compat_sys_preadv64(fd, vec, vlen, pos);
@@ -1031,9 +1031,9 @@ static size_t compat_writev(struct file *file,
 	return ret;
 }
 
-COMPAT_SYSCALL_DEFINE3(writev, unsigned long, fd,
+COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd,
 		const struct compat_iovec __user *, vec,
-		unsigned long, vlen)
+		compat_ulong_t, vlen)
 {
 	struct fd f = fdget(fd);
 	ssize_t ret;
@@ -1068,9 +1068,9 @@ COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd,
 	return ret;
 }
 
-COMPAT_SYSCALL_DEFINE5(pwritev, unsigned long, fd,
+COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd,
 		const struct compat_iovec __user *,vec,
-		unsigned long, vlen, u32, pos_low, u32, pos_high)
+		compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
 {
 	loff_t pos = ((loff_t)pos_high << 32) | pos_low;
 	return compat_sys_pwritev64(fd, vec, vlen, pos);
diff --git a/include/linux/compat.h b/include/linux/compat.h
@@ -327,16 +327,16 @@ asmlinkage long compat_sys_keyctl(u32 option,
 			      u32 arg2, u32 arg3, u32 arg4, u32 arg5);
 asmlinkage long compat_sys_ustat(unsigned dev, struct compat_ustat __user *u32);
 
-asmlinkage ssize_t compat_sys_readv(unsigned long fd,
-		const struct compat_iovec __user *vec, unsigned long vlen);
-asmlinkage ssize_t compat_sys_writev(unsigned long fd,
-		const struct compat_iovec __user *vec, unsigned long vlen);
-asmlinkage ssize_t compat_sys_preadv(unsigned long fd,
+asmlinkage ssize_t compat_sys_readv(compat_ulong_t fd,
+		const struct compat_iovec __user *vec, compat_ulong_t vlen);
+asmlinkage ssize_t compat_sys_writev(compat_ulong_t fd,
+		const struct compat_iovec __user *vec, compat_ulong_t vlen);
+asmlinkage ssize_t compat_sys_preadv(compat_ulong_t fd,
 		const struct compat_iovec __user *vec,
-		unsigned long vlen, u32 pos_low, u32 pos_high);
-asmlinkage ssize_t compat_sys_pwritev(unsigned long fd,
+		compat_ulong_t vlen, u32 pos_low, u32 pos_high);
+asmlinkage ssize_t compat_sys_pwritev(compat_ulong_t fd,
 		const struct compat_iovec __user *vec,
-		unsigned long vlen, u32 pos_low, u32 pos_high);
+		compat_ulong_t vlen, u32 pos_low, u32 pos_high);
 asmlinkage long comat_sys_lseek(unsigned int, compat_off_t, unsigned int);
 
 asmlinkage long compat_sys_execve(const char __user *filename, const compat_uptr_t __user *argv,

Original file line number	Diff line number	Diff line change
`@@ -964,9 +964,9 @@ static size_t compat_readv(struct file *file,`
`964`	`964`	`return ret;`
`965`	`965`	`}`
`966`	`966`
`967`		`-COMPAT_SYSCALL_DEFINE3(readv, unsigned long, fd,`
	`967`	`+COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd,`
`968`	`968`	`const struct compat_iovec __user *,vec,`
`969`		`- unsigned long, vlen)`
	`969`	`+ compat_ulong_t, vlen)`
`970`	`970`	`{`
`971`	`971`	`struct fd f = fdget(fd);`
`972`	`972`	`ssize_t ret;`
`@@ -1001,9 +1001,9 @@ COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd,`
`1001`	`1001`	`return ret;`
`1002`	`1002`	`}`
`1003`	`1003`
`1004`		`-COMPAT_SYSCALL_DEFINE5(preadv, unsigned long, fd,`
	`1004`	`+COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd,`
`1005`	`1005`	`const struct compat_iovec __user *,vec,`
`1006`		`- unsigned long, vlen, u32, pos_low, u32, pos_high)`
	`1006`	`+ compat_ulong_t, vlen, u32, pos_low, u32, pos_high)`
`1007`	`1007`	`{`
`1008`	`1008`	`loff_t pos = ((loff_t)pos_high << 32) \| pos_low;`
`1009`	`1009`	`return compat_sys_preadv64(fd, vec, vlen, pos);`
`@@ -1031,9 +1031,9 @@ static size_t compat_writev(struct file *file,`
`1031`	`1031`	`return ret;`
`1032`	`1032`	`}`
`1033`	`1033`
`1034`		`-COMPAT_SYSCALL_DEFINE3(writev, unsigned long, fd,`
	`1034`	`+COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd,`
`1035`	`1035`	`const struct compat_iovec __user *, vec,`
`1036`		`- unsigned long, vlen)`
	`1036`	`+ compat_ulong_t, vlen)`
`1037`	`1037`	`{`
`1038`	`1038`	`struct fd f = fdget(fd);`
`1039`	`1039`	`ssize_t ret;`
`@@ -1068,9 +1068,9 @@ COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd,`
`1068`	`1068`	`return ret;`
`1069`	`1069`	`}`
`1070`	`1070`
`1071`		`-COMPAT_SYSCALL_DEFINE5(pwritev, unsigned long, fd,`
	`1071`	`+COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd,`
`1072`	`1072`	`const struct compat_iovec __user *,vec,`
`1073`		`- unsigned long, vlen, u32, pos_low, u32, pos_high)`
	`1073`	`+ compat_ulong_t, vlen, u32, pos_low, u32, pos_high)`
`1074`	`1074`	`{`
`1075`	`1075`	`loff_t pos = ((loff_t)pos_high << 32) \| pos_low;`
`1076`	`1076`	`return compat_sys_pwritev64(fd, vec, vlen, pos);`