Unionfs: use poison.h for safe poison pointers

This also fixes a compile warning on 64-bit systems.

Signed-off-by: Josef 'Jeff' Sipek <jsipek@cs.sunysb.edu>
Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>

diff --git a/fs/unionfs/debug.c b/fs/unionfs/debug.c
index 09b52cec96738ab57523c2bc52c140cbf3cfa40d..b103eb959f9687875ae3af3f908b4c1827865477 100644 (file)
--- a/fs/unionfs/debug.c
+++ b/fs/unionfs/debug.c
@@ -25,14 +25,6 @@
                }                                                       \
        } while (0)
 
-#if BITS_PER_LONG == 32
-#define POISONED_PTR           ((void*) 0x5a5a5a5a)
-#elif BITS_PER_LONG == 64
-#define POISONED_PTR           ((void*) 0x5a5a5a5a5a5a5a5a)
-#else
-#error Unknown BITS_PER_LONG value
-#endif /* BITS_PER_LONG != known */
-
 /*
  * __unionfs_check_{inode,dentry,file} perform exhaustive sanity checking on
  * the fan-out of various Unionfs objects.  We check that no lower objects
@@ -50,6 +42,7 @@ void __unionfs_check_inode(const struct inode *inode,
        struct inode *lower_inode;
        struct super_block *sb;
        int printed_caller = 0;
+       void *poison_ptr;
 
        /* for inodes now */
        BUG_ON(!inode);
@@ -88,12 +81,13 @@ void __unionfs_check_inode(const struct inode *inode,
                }
                lower_inode = unionfs_lower_inode_idx(inode, bindex);
                if (lower_inode) {
+                       memset(&poison_ptr, POISON_INUSE, sizeof(void *));
                        if (unlikely(bindex < istart || bindex > iend)) {
                                PRINT_CALLER(fname, fxn, line);
                                printk(" Ci5: inode/linode=%p:%p bindex=%d "
                                       "istart/end=%d:%d\n", inode,
                                       lower_inode, bindex, istart, iend);
-                       } else if (unlikely(lower_inode == POISONED_PTR)) {
+                       } else if (unlikely(lower_inode == poison_ptr)) {
                                /* freed inode! */
                                PRINT_CALLER(fname, fxn, line);
                                printk(" Ci6: inode/linode=%p:%p bindex=%d "
@@ -131,6 +125,7 @@ void __unionfs_check_dentry(const struct dentry *dentry,
        struct super_block *sb;
        struct vfsmount *lower_mnt;
        int printed_caller = 0;
+       void *poison_ptr;
 
        BUG_ON(!dentry);
        sb = dentry->d_sb;
@@ -257,12 +252,13 @@ void __unionfs_check_dentry(const struct dentry *dentry,
        for (bindex = sbstart(sb); bindex < sbmax(sb); bindex++) {
                lower_inode = unionfs_lower_inode_idx(inode, bindex);
                if (lower_inode) {
+                       memset(&poison_ptr, POISON_INUSE, sizeof(void *));
                        if (unlikely(bindex < istart || bindex > iend)) {
                                PRINT_CALLER(fname, fxn, line);
                                printk(" CI5: dentry/linode=%p:%p bindex=%d "
                                       "istart/end=%d:%d\n", dentry,
                                       lower_inode, bindex, istart, iend);
-                       } else if (unlikely(lower_inode == POISONED_PTR)) {
+                       } else if (unlikely(lower_inode == poison_ptr)) {
                                /* freed inode! */
                                PRINT_CALLER(fname, fxn, line);
                                printk(" CI6: dentry/linode=%p:%p bindex=%d "

diff --git a/fs/unionfs/union.h b/fs/unionfs/union.h
index c371bef1907ac8f03be34aaf4d585aa36bd3c472..cfecf553c32489d68db8751d20fd051b0abb4067 100644 (file)
--- a/fs/unionfs/union.h
+++ b/fs/unionfs/union.h
@@ -43,6 +43,7 @@
 #include <linux/fs_stack.h>
 #include <linux/magic.h>
 #include <linux/log2.h>
+#include <linux/poison.h>
 
 #include <asm/mman.h>
 #include <asm/system.h>