[PATCH 1/2] proc: fix inode number bogorithmetic

[linux-2.6-omap-h63xx.git] / fs / proc / generic.c

diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index cb4096cc3fb7456f96a5a4e30dc1957e0707b10e..b85e36e153bad4053f4af7a3a1a1294813865542 100644 (file)
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -303,7 +303,7 @@ out:
 static DEFINE_IDR(proc_inum_idr);
 static DEFINE_SPINLOCK(proc_inum_lock); /* protects the above */
 
-#define PROC_DYNAMIC_FIRST 0xF0000000UL
+#define PROC_DYNAMIC_FIRST 0xF0000000U
 
 /*
  * Return an inode number between PROC_DYNAMIC_FIRST and
@@ -311,7 +311,7 @@ static DEFINE_SPINLOCK(proc_inum_lock); /* protects the above */
  */
 static unsigned int get_inode_number(void)
 {
-       int i, inum = 0;
+       unsigned int i;
        int error;
 
 retry:
@@ -326,21 +326,18 @@ retry:
        else if (error)
                return 0;
 
-       inum = (i & MAX_ID_MASK) + PROC_DYNAMIC_FIRST;
-
-       /* inum will never be more than 0xf0ffffff, so no check
-        * for overflow.
-        */
-
-       return inum;
+       if (i > UINT_MAX - PROC_DYNAMIC_FIRST) {
+               spin_lock(&proc_inum_lock);
+               idr_remove(&proc_inum_idr, i);
+               spin_unlock(&proc_inum_lock);
+       }
+       return PROC_DYNAMIC_FIRST + i;
 }
 
 static void release_inode_number(unsigned int inum)
 {
-       int id = (inum - PROC_DYNAMIC_FIRST) | ~MAX_ID_MASK;
-
        spin_lock(&proc_inum_lock);
-       idr_remove(&proc_inum_idr, id);
+       idr_remove(&proc_inum_idr, inum - PROC_DYNAMIC_FIRST);
        spin_unlock(&proc_inum_lock);
 }