This is a note to let you know that I've just added the patch titled

    m68k: Truncate base in do_div()

to the 3.4-stable tree which can be found at:
    
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     m68k-truncate-base-in-do_div.patch
and it can be found in the queue-3.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.


>From ea077b1b96e073eac5c3c5590529e964767fc5f7 Mon Sep 17 00:00:00 2001
From: Andreas Schwab <[email protected]>
Date: Fri, 9 Aug 2013 15:14:08 +0200
Subject: m68k: Truncate base in do_div()

From: Andreas Schwab <[email protected]>

commit ea077b1b96e073eac5c3c5590529e964767fc5f7 upstream.

Explicitly truncate the second operand of do_div() to 32 bits to guard
against bogus code calling it with a 64-bit divisor.

[Thorsten]

After upgrading from 3.2 to 3.10, mounting a btrfs volume fails with:

btrfs: setting nodatacow, compression disabled
btrfs: enabling auto recovery
btrfs: disk space caching is enabled
---
 arch/m68k/include/asm/div64.h |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

--- a/arch/m68k/include/asm/div64.h
+++ b/arch/m68k/include/asm/div64.h
@@ -15,16 +15,17 @@
                unsigned long long n64;                         \
        } __n;                                                  \
        unsigned long __rem, __upper;                           \
+       unsigned long __base = (base);                          \
                                                                \
        __n.n64 = (n);                                          \
        if ((__upper = __n.n32[0])) {                           \
                asm ("divul.l %2,%1:%0"                         \
-                       : "=d" (__n.n32[0]), "=d" (__upper)     \
-                       : "d" (base), "0" (__n.n32[0]));        \
+                    : "=d" (__n.n32[0]), "=d" (__upper)        \
+                    : "d" (__base), "0" (__n.n32[0]));         \
        }                                                       \
        asm ("divu.l %2,%1:%0"                                  \
-               : "=d" (__n.n32[1]), "=d" (__rem)               \
-               : "d" (base), "1" (__upper), "0" (__n.n32[1])); \
+            : "=d" (__n.n32[1]), "=d" (__rem)                  \
+            : "d" (__base), "1" (__upper), "0" (__n.n32[1]));  \
        (n) = __n.n64;                                          \
        __rem;                                                  \
 })


Patches currently in stable-queue which might be from [email protected] are

queue-3.4/m68k-truncate-base-in-do_div.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to