diff options
| author | Andrew Morton <akpm@linux-foundation.org> | 2016-02-12 03:13:14 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-02-12 05:35:48 +0300 |
| commit | 4a389810bc3cb0e73443104f0827e81e23cb1e12 (patch) | |
| tree | 00c0ed0ee923222bbf68bc23ed88450120745428 /include | |
| parent | 6b75d14912f2d89a3539c0b3a100519e1eec9a63 (diff) | |
| download | linux-4a389810bc3cb0e73443104f0827e81e23cb1e12.tar.xz | |
kernel/locking/lockdep.c: convert hash tables to hlists
Mike said:
: CONFIG_UBSAN_ALIGNMENT breaks x86-64 kernel with lockdep enabled, i. e
: kernel with CONFIG_UBSAN_ALIGNMENT 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.
lockdep_init() and lockdep_initialized can be done away with now - a 4.6
patch has been prepared to do this.
Reported-by: Mike Krinkin <krinkin.m.u@gmail.com>
Suggested-by: Mike Krinkin <krinkin.m.u@gmail.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/lockdep.h | 4 |
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; }; |