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author | Stephen Boyd <sboyd@codeaurora.org> | 2012-12-19 23:39:48 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-12-20 13:50:16 -0800 |
commit | fcc16882ac4532aaa644bff444f0c5d6228ba71e (patch) | |
tree | 7104729ed7fd136a26ea47462e716410666aa1f6 /Documentation | |
parent | 787314c35fbb97e02823a1b8eb8cfa58f366cd49 (diff) | |
download | linux-fcc16882ac4532aaa644bff444f0c5d6228ba71e.tar.bz2 |
lib: atomic64: Initialize locks statically to fix early users
The atomic64 library uses a handful of static spin locks to implement
atomic 64-bit operations on architectures without support for atomic
64-bit instructions.
Unfortunately, the spinlocks are initialized in a pure initcall and that
is too late for the vfs namespace code which wants to use atomic64
operations before the initcall is run.
This became a problem as of commit 8823c079ba71: "vfs: Add setns support
for the mount namespace".
This leads to BUG messages such as:
BUG: spinlock bad magic on CPU#0, swapper/0/0
lock: atomic64_lock+0x240/0x400, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
do_raw_spin_lock+0x158/0x198
_raw_spin_lock_irqsave+0x4c/0x58
atomic64_add_return+0x30/0x5c
alloc_mnt_ns.clone.14+0x44/0xac
create_mnt_ns+0xc/0x54
mnt_init+0x120/0x1d4
vfs_caches_init+0xe0/0x10c
start_kernel+0x29c/0x300
coming out early on during boot when spinlock debugging is enabled.
Fix this by initializing the spinlocks statically at compile time.
Reported-and-tested-by: Vaibhav Bedia <vaibhav.bedia@ti.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation')
0 files changed, 0 insertions, 0 deletions