Linux futex_wait() bug – update to latest patches now

Re:Linux futex_wait() bug – update to latest patches now by buster on Thursday May 14, 2015 @07:03AM (#9544357)

Please note that i was just looking for the missing default case. It might still be the case that the bug is not in precise..

The patch also replaces atomic_inc() with futex_get_mm():

  -		atomic_inc(&key->private.mm->mm_count);
  +		futex_get_mm(key); /* implies MB (B) */

And your links are using atomic_inc().. What that means with regards to this bug? I don't know.

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Re:Linux futex_wait() bug – update to latest patches now by kasabali on Thursday May 14, 2015 @07:11AM (#9544381)

Fix commit and OP claims bug was introduced in [1], which has been never backported to 3.2.x, so I assume lack of default case was not a problem before that commit.

> And your links are using atomic_inc().. What that means with regards to this bug? I don't know.

It means they are simply old versions and they were never affected by the bug, if we believe the commit message of the fix commit and OP.

[1] https://github.com/torvalds/linux/commit/b0c29f79ecea0b6fbce...

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Re:Linux futex_wait() bug – update to latest patches now by buster on Thursday May 14, 2015 @08:23AM (#9544672)

Or not recognized.. But you are right, i suppose that the atomic_inc() doesn't need a memory barrier because it's atomic and the new function may need one, guessing.

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