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* [PATCH 0/2] use symbolic constants in generic lseek code
@ 2007-02-20 21:57 Chris Snook
  2007-02-20 22:01 ` [PATCH 1/2] " Chris Snook
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: Chris Snook @ 2007-02-20 21:57 UTC (permalink / raw)
  To: linux-kernel; +Cc: akpm, dhowells, jeffpc, csnook

The generic lseek code in fs/read_write.c uses hardcoded values for
SEEK_{SET,CUR,END}.

Patch 1 fixes the case statements to use the symbolic constants in
include/linux/fs.h, and should not be at all controversial.

Patch 2 adds a SEEK_MAX and uses it to validate user arguments.  This makes
the code a little cleaner and also enables future extensions (such as
SEEK_DATA and SEEK_HOLE).  If anyone has a problem with this, please speak up.

-- Chris


^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH 1/2] use symbolic constants in generic lseek code
  2007-02-20 21:57 [PATCH 0/2] use symbolic constants in generic lseek code Chris Snook
@ 2007-02-20 22:01 ` Chris Snook
  2007-02-20 22:05 ` [PATCH 2/2] use use SEEK_MAX to validate user lseek arguments Chris Snook
  2007-02-21 11:38 ` [PATCH 0/2] use symbolic constants in generic lseek code David Howells
  2 siblings, 0 replies; 4+ messages in thread
From: Chris Snook @ 2007-02-20 22:01 UTC (permalink / raw)
  To: Chris Snook, linux-kernel; +Cc: akpm, dhowells, jeffpc, csnook

From: Chris Snook <csnook@redhat.com>

Convert magic numbers to SEEK_* values from fs.h

Signed-off-by: Chris Snook <csnook@redhat.com>
--
--- a/fs/read_write.c	2007-02-20 14:49:45.000000000 -0500
+++ b/fs/read_write.c	2007-02-20 16:48:39.000000000 -0500
@@ -37,10 +37,10 @@ loff_t generic_file_llseek(struct file *

 	mutex_lock(&inode->i_mutex);
 	switch (origin) {
-		case 2:
+		case SEEK_END:
 			offset += inode->i_size;
 			break;
-		case 1:
+		case SEEK_CUR:
 			offset += file->f_pos;
 	}
 	retval = -EINVAL;
@@ -63,10 +63,10 @@ loff_t remote_llseek(struct file *file,

 	lock_kernel();
 	switch (origin) {
-		case 2:
+		case SEEK_END:
 			offset += i_size_read(file->f_path.dentry->d_inode);
 			break;
-		case 1:
+		case SEEK_CUR:
 			offset += file->f_pos;
 	}
 	retval = -EINVAL;
@@ -94,10 +94,10 @@ loff_t default_llseek(struct file *file,

 	lock_kernel();
 	switch (origin) {
-		case 2:
+		case SEEK_END:
 			offset += i_size_read(file->f_path.dentry->d_inode);
 			break;
-		case 1:
+		case SEEK_CUR:
 			offset += file->f_pos;
 	}
 	retval = -EINVAL;


^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH 2/2] use use SEEK_MAX to validate user lseek arguments
  2007-02-20 21:57 [PATCH 0/2] use symbolic constants in generic lseek code Chris Snook
  2007-02-20 22:01 ` [PATCH 1/2] " Chris Snook
@ 2007-02-20 22:05 ` Chris Snook
  2007-02-21 11:38 ` [PATCH 0/2] use symbolic constants in generic lseek code David Howells
  2 siblings, 0 replies; 4+ messages in thread
From: Chris Snook @ 2007-02-20 22:05 UTC (permalink / raw)
  To: Chris Snook, linux-kernel; +Cc: akpm, dhowells, jeffpc, csnook

From: Chris Snook <csnook@redhat.com>

Add SEEK_MAX and use it to validate lseek arguments from userspace.

Signed-off-by: Chris Snook <csnook@redhat.com>
--
diff -urp b/fs/read_write.c c/fs/read_write.c
--- b/fs/read_write.c	2007-02-20 16:48:39.000000000 -0500
+++ c/fs/read_write.c	2007-02-20 16:55:46.000000000 -0500
@@ -139,7 +139,7 @@ asmlinkage off_t sys_lseek(unsigned int
 		goto bad;

 	retval = -EINVAL;
-	if (origin <= 2) {
+	if (origin <= SEEK_MAX) {
 		loff_t res = vfs_llseek(file, offset, origin);
 		retval = res;
 		if (res != (loff_t)retval)
@@ -166,7 +166,7 @@ asmlinkage long sys_llseek(unsigned int
 		goto bad;

 	retval = -EINVAL;
-	if (origin > 2)
+	if (origin > SEEK_MAX)
 		goto out_putf;

 	offset = vfs_llseek(file, ((loff_t) offset_high << 32) | offset_low,
diff -urp b/include/linux/fs.h c/include/linux/fs.h
--- b/include/linux/fs.h	2007-02-20 14:49:46.000000000 -0500
+++ c/include/linux/fs.h	2007-02-20 16:54:30.000000000 -0500
@@ -30,6 +30,7 @@
 #define SEEK_SET	0	/* seek relative to beginning of file */
 #define SEEK_CUR	1	/* seek relative to current file position */
 #define SEEK_END	2	/* seek relative to end of file */
+#define SEEK_MAX	SEEK_END

 /* And dynamically-tunable limits and defaults: */
 struct files_stat_struct {


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH 0/2] use symbolic constants in generic lseek code 
  2007-02-20 21:57 [PATCH 0/2] use symbolic constants in generic lseek code Chris Snook
  2007-02-20 22:01 ` [PATCH 1/2] " Chris Snook
  2007-02-20 22:05 ` [PATCH 2/2] use use SEEK_MAX to validate user lseek arguments Chris Snook
@ 2007-02-21 11:38 ` David Howells
  2 siblings, 0 replies; 4+ messages in thread
From: David Howells @ 2007-02-21 11:38 UTC (permalink / raw)
  To: Chris Snook; +Cc: linux-kernel, akpm, jeffpc

Chris Snook <csnook@redhat.com> wrote:

> Patch 1 fixes the case statements to use the symbolic constants in
> include/linux/fs.h, and should not be at all controversial.
>
> Patch 2 adds a SEEK_MAX and uses it to validate user arguments.  This makes
> the code a little cleaner and also enables future extensions (such as
> SEEK_DATA and SEEK_HOLE).  If anyone has a problem with this, please speak up.

Seems reasonable.

Acked-By: David Howells <dhowells@redhat.com>

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2007-02-21 11:39 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2007-02-20 21:57 [PATCH 0/2] use symbolic constants in generic lseek code Chris Snook
2007-02-20 22:01 ` [PATCH 1/2] " Chris Snook
2007-02-20 22:05 ` [PATCH 2/2] use use SEEK_MAX to validate user lseek arguments Chris Snook
2007-02-21 11:38 ` [PATCH 0/2] use symbolic constants in generic lseek code David Howells

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