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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-03-14 14:53:07 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-03-14 14:53:07 -0700 |
| commit | f4846e52c51755fe1dd6642a117bc23cd0655c95 (patch) | |
| tree | a0ab601287af471e3e9d18fe1cdde574c7f6bf85 | |
| parent | 40e4591d949469d089714518385e4a99071a1762 (diff) | |
| parent | f65846a1800ef8c48d1ae1973c30dae4c356a800 (diff) | |
Merge branch 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
Pull fix for hlist_entry_safe() regression from Paul McKenney:
"This contains a single commit that fixes a regression in
hlist_entry_safe(). This macro references its argument twice, which
can cause NULL-pointer errors. This commit applies a gcc statement
expression, creating a temporary variable to avoid the double
reference. This has been posted to LKML at
https://lkml.org/lkml/2013/3/9/75.
Kudos to CAI Qian, whose testing uncovered this, to Eric Dumazet, who
spotted root cause, and to Li Zefan, who tested this commit."
* 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
list: Fix double fetch of pointer in hlist_entry_safe()
| -rw-r--r-- | include/linux/list.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/include/linux/list.h b/include/linux/list.h index d991cc147c9..6a1f8df9144 100644 --- a/include/linux/list.h +++ b/include/linux/list.h @@ -667,7 +667,9 @@ static inline void hlist_move_list(struct hlist_head *old, pos = n) #define hlist_entry_safe(ptr, type, member) \ - (ptr) ? hlist_entry(ptr, type, member) : NULL + ({ typeof(ptr) ____ptr = (ptr); \ + ____ptr ? hlist_entry(____ptr, type, member) : NULL; \ + }) /** * hlist_for_each_entry - iterate over list of given type |