| Message ID | 1355989188-17665-1-git-send-email-sboyd@codeaurora.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
* Stephen Boyd <sboyd@codeaurora.org> [121219 23:42]: > 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 (introduced by 8823c07 "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 > [<c001af64>] (unwind_backtrace+0x0/0xf0) from [<c02c2010>] (do_raw_spin_lock+0x158/0x198) > [<c02c2010>] (do_raw_spin_lock+0x158/0x198) from [<c04d89ec>] (_raw_spin_lock_irqsave+0x4c/0x58) > [<c04d89ec>] (_raw_spin_lock_irqsave+0x4c/0x58) from [<c02cabf0>] (atomic64_add_return+0x30/0x5c) > [<c02cabf0>] (atomic64_add_return+0x30/0x5c) from [<c0124564>] (alloc_mnt_ns.clone.14+0x44/0xac) > [<c0124564>] (alloc_mnt_ns.clone.14+0x44/0xac) from [<c0124f4c>] (create_mnt_ns+0xc/0x54) > [<c0124f4c>] (create_mnt_ns+0xc/0x54) from [<c06f31a4>] (mnt_init+0x120/0x1d4) > [<c06f31a4>] (mnt_init+0x120/0x1d4) from [<c06f2d50>] (vfs_caches_init+0xe0/0x10c) > [<c06f2d50>] (vfs_caches_init+0xe0/0x10c) from [<c06d4798>] (start_kernel+0x29c/0x300) > [<c06d4798>] (start_kernel+0x29c/0x300) from [<80008078>] (0x80008078) > > coming out early on during boot when spinlock debugging is enabled. > > Fix this problem by initializing the spinlocks statically at > compile time. > > Reported-by: Vaibhav Bedia <vaibhav.bedia@ti.com> > Tested-by: Vaibhav Bedia <vaibhav.bedia@ti.com> > Cc: Eric W. Biederman <ebiederm@xmission.com> > Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> > --- > > Sorry Andrew, I couldn't find a maintainer of this file so I > am picking on you. Works for me: Tested-by: Tony Lindgren <tony@atomide.com> Added Linus, Benjamin and David to Cc as this came up on the ARM list. > lib/atomic64.c | 17 +++++------------ > 1 file changed, 5 insertions(+), 12 deletions(-) > > diff --git a/lib/atomic64.c b/lib/atomic64.c > index 9785378..08a4f06 100644 > --- a/lib/atomic64.c > +++ b/lib/atomic64.c > @@ -31,7 +31,11 @@ > static union { > raw_spinlock_t lock; > char pad[L1_CACHE_BYTES]; > -} atomic64_lock[NR_LOCKS] __cacheline_aligned_in_smp; > +} atomic64_lock[NR_LOCKS] __cacheline_aligned_in_smp = { > + [0 ... (NR_LOCKS - 1)] = { > + .lock = __RAW_SPIN_LOCK_UNLOCKED(atomic64_lock.lock), > + }, > +}; > > static inline raw_spinlock_t *lock_addr(const atomic64_t *v) > { > @@ -173,14 +177,3 @@ int atomic64_add_unless(atomic64_t *v, long long a, long long u) > return ret; > } > EXPORT_SYMBOL(atomic64_add_unless); > - > -static int init_atomic64_lock(void) > -{ > - int i; > - > - for (i = 0; i < NR_LOCKS; ++i) > - raw_spin_lock_init(&atomic64_lock[i].lock); > - return 0; > -} > - > -pure_initcall(init_atomic64_lock); > -- > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, > hosted by The Linux Foundation > > -- > To unsubscribe from this list: send the line "unsubscribe linux-omap" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/lib/atomic64.c b/lib/atomic64.c index 9785378..08a4f06 100644 --- a/lib/atomic64.c +++ b/lib/atomic64.c @@ -31,7 +31,11 @@ static union { raw_spinlock_t lock; char pad[L1_CACHE_BYTES]; -} atomic64_lock[NR_LOCKS] __cacheline_aligned_in_smp; +} atomic64_lock[NR_LOCKS] __cacheline_aligned_in_smp = { + [0 ... (NR_LOCKS - 1)] = { + .lock = __RAW_SPIN_LOCK_UNLOCKED(atomic64_lock.lock), + }, +}; static inline raw_spinlock_t *lock_addr(const atomic64_t *v) { @@ -173,14 +177,3 @@ int atomic64_add_unless(atomic64_t *v, long long a, long long u) return ret; } EXPORT_SYMBOL(atomic64_add_unless); - -static int init_atomic64_lock(void) -{ - int i; - - for (i = 0; i < NR_LOCKS; ++i) - raw_spin_lock_init(&atomic64_lock[i].lock); - return 0; -} - -pure_initcall(init_atomic64_lock);