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authorAndrew Morton <akpm@linux-foundation.org>2016-02-03 13:44:12 -0800
committerIngo Molnar <mingo@kernel.org>2016-02-09 12:03:25 +0100
commita63f38cc4ccfa076f87fc3d0c276ee62e710f953 (patch)
tree2c00ddc832f5f814958b54efca84506e4de64108 /include/linux/lockdep.h
parent3aa6b46c6d6d0f89395ec3811a77fe22e57fa0d3 (diff)
locking/lockdep: Convert hash tables to hlists
Mike said: : CONFIG_UBSAN_ALIGNMENT breaks x86-64 kernel with lockdep enabled, i.e. : kernel with CONFIG_UBSAN_ALIGNMENT=y fails to load without even any error : message. : : The problem is that ubsan callbacks use spinlocks and might be called : before lockdep is initialized. Particularly this line in the : reserve_ebda_region function causes problem: : : lowmem = *(unsigned short *)__va(BIOS_LOWMEM_KILOBYTES); : : If i put lockdep_init() before reserve_ebda_region call in : x86_64_start_reservations kernel loads well. Fix this ordering issue permanently: change lockdep so that it uses hlists for the hash tables. Unlike a list_head, an hlist_head is in its initialized state when it is all-zeroes, so lockdep is ready for operation immediately upon boot - lockdep_init() need not have run. The patch will also save some memory. Probably lockdep_init() and lockdep_initialized can be done away with now. Suggested-by: Mike Krinkin <krinkin.m.u@gmail.com> Reported-by: Mike Krinkin <krinkin.m.u@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Cc: mm-commits@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/lockdep.h')
-rw-r--r--include/linux/lockdep.h4
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index c57e424d914b..4dca42fd32f5 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -66,7 +66,7 @@ struct lock_class {
/*
* class-hash:
*/
- struct list_head hash_entry;
+ struct hlist_node hash_entry;
/*
* global list of all lock-classes:
@@ -199,7 +199,7 @@ struct lock_chain {
u8 irq_context;
u8 depth;
u16 base;
- struct list_head entry;
+ struct hlist_node entry;
u64 chain_key;
};