| Message ID | 50D2224E.4060300@codeaurora.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Dec 20, 2012 at 01:53:42, Stephen Boyd wrote: > On 12/19/12 08:53, Paul Walmsley wrote: > > On Wed, 19 Dec 2012, Bedia, Vaibhav wrote: > > > >> Current mainline on Beaglebone using the omap2plus_defconfig + 3 build fixes > >> is triggering a BUG() > > ... > > > >> [ 0.109688] Security Framework initialized > >> [ 0.109889] Mount-cache hash table entries: 512 > >> [ 0.112674] BUG: spinlock bad magic on CPU#0, swapper/0/0 > >> [ 0.112724] lock: atomic64_lock+0x240/0x400, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0 > >> [ 0.112782] [<c001af64>] (unwind_backtrace+0x0/0xf0) from [<c02c2010>] (do_raw_spin_lock+0x158/0x198) > >> [ 0.112813] [<c02c2010>] (do_raw_spin_lock+0x158/0x198) from [<c04d89ec>] (_raw_spin_lock_irqsave+0x4c/0x58) > >> [ 0.112844] [<c04d89ec>] (_raw_spin_lock_irqsave+0x4c/0x58) from [<c02cabf0>] (atomic64_add_return+0x30/0x5c) > >> [ 0.112886] [<c02cabf0>] (atomic64_add_return+0x30/0x5c) from [<c0124564>] (alloc_mnt_ns.clone.14+0x44/0xac) > >> [ 0.112914] [<c0124564>] (alloc_mnt_ns.clone.14+0x44/0xac) from [<c0124f4c>] (create_mnt_ns+0xc/0x54) > >> [ 0.112951] [<c0124f4c>] (create_mnt_ns+0xc/0x54) from [<c06f31a4>] (mnt_init+0x120/0x1d4) > >> [ 0.112978] [<c06f31a4>] (mnt_init+0x120/0x1d4) from [<c06f2d50>] (vfs_caches_init+0xe0/0x10c) > >> [ 0.113005] [<c06f2d50>] (vfs_caches_init+0xe0/0x10c) from [<c06d4798>] (start_kernel+0x29c/0x300) > >> [ 0.113029] [<c06d4798>] (start_kernel+0x29c/0x300) from [<80008078>] (0x80008078) > >> [ 0.118290] CPU: Testing write buffer coherency: ok > >> [ 0.118968] CPU0: thread -1, cpu 0, socket -1, mpidr 0 > >> [ 0.119053] Setting up static identity map for 0x804de2c8 - 0x804de338 > >> [ 0.120698] Brought up 1 CPUs > > This is probably a memory corruption bug, there's probably some code > > executing early that's writing outside its own data and trashing some > > previously-allocated memory. > > I'm not so sure. It looks like atomic64s use spinlocks on processors > that don't have 64-bit atomic instructions (see lib/atomic64.c). And > those spinlocks are not initialized until a pure initcall runs, > init_atomic64_lock(). Pure initcalls don't run until after > vfs_caches_init() and so you get this BUG() warning that the spinlock is > not initialized. > > How about we initialize the locks statically? Does that fix your problem? > > ---->8----- > > 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); > I tried out 3 variants of AM335x boards - 2 of these (BeagleBone and EVM) have DDR2 and 1 has DDR3 (EVM-SK). The BUG is triggered on all of these at the same point. With Stephen's change I don't see this on any of the board variants :) New bootlog below. Thanks, Vaibhav --- [ 0.000000] Booting Linux on physical CPU 0x0 [ 0.000000] Linux version 3.7.0-01415-g55bc169-dirty (a0393953@psplinux063) (gcc version 4.5.3 20110311 (prerelease) (GCC) ) #4 SMP Thu Dec 20 09:59:12 IST 2012 [ 0.000000] CPU: ARMv7 Processor [413fc082] revision 2 (ARMv7), cr=10c53c7d [ 0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache [ 0.000000] Machine: Generic AM33XX (Flattened Device Tree), model: TI AM335x BeagleBone [ 0.000000] Memory policy: ECC disabled, Data cache writeback [ 0.000000] AM335X ES1.0 (neon ) [ 0.000000] PERCPU: Embedded 9 pages/cpu @c0f1a000 s12992 r8192 d15680 u36864 [ 0.000000] Built 1 zonelists in Zone order, mobility grouping on. Total pages: 64768 [ 0.000000] Kernel command line: console=ttyO0,115200n8 mem=256M root=/dev/ram rw initrd=0x82000000,16MB ramdisk_size=65536 earlyprintk=serial [ 0.000000] PID hash table entries: 1024 (order: 0, 4096 bytes) [ 0.000000] Dentry cache hash table entries: 32768 (order: 5, 131072 bytes) [ 0.000000] Inode-cache hash table entries: 16384 (order: 4, 65536 bytes) [ 0.000000] __ex_table already sorted, skipping sort [ 0.000000] Memory: 255MB = 255MB total [ 0.000000] Memory: 229012k/229012k available, 33132k reserved, 0K highmem [ 0.000000] Virtual kernel memory layout: [ 0.000000] vector : 0xffff0000 - 0xffff1000 ( 4 kB) [ 0.000000] fixmap : 0xfff00000 - 0xfffe0000 ( 896 kB) [ 0.000000] vmalloc : 0xd0800000 - 0xff000000 ( 744 MB) [ 0.000000] lowmem : 0xc0000000 - 0xd0000000 ( 256 MB) [ 0.000000] pkmap : 0xbfe00000 - 0xc0000000 ( 2 MB) [ 0.000000] modules : 0xbf000000 - 0xbfe00000 ( 14 MB) [ 0.000000] .text : 0xc0008000 - 0xc06d3f34 (6960 kB) [ 0.000000] .init : 0xc06d4000 - 0xc07252c0 ( 325 kB) [ 0.000000] .data : 0xc0726000 - 0xc07b6068 ( 577 kB) [ 0.000000] .bss : 0xc07b608c - 0xc0d10af0 (5483 kB) [ 0.000000] Hierarchical RCU implementation. [ 0.000000] RCU restricting CPUs from NR_CPUS=2 to nr_cpu_ids=1. [ 0.000000] NR_IRQS:16 nr_irqs:16 16 [ 0.000000] IRQ: Found an INTC at 0xfa200000 (revision 5.0) with 128 interrupts [ 0.000000] Total of 128 interrupts on 1 active controller [ 0.000000] OMAP clockevent source: GPTIMER1 at 24000000 Hz [ 0.000000] sched_clock: 32 bits at 24MHz, resolution 41ns, wraps every 178956ms [ 0.000000] OMAP clocksource: GPTIMER2 at 24000000 Hz [ 0.000000] Console: colour dummy device 80x30 [ 0.000000] Lock dependency validator: Copyright (c) 2006 Red Hat, Inc., Ingo Molnar [ 0.000000] ... MAX_LOCKDEP_SUBCLASSES: 8 [ 0.000000] ... MAX_LOCK_DEPTH: 48 [ 0.000000] ... MAX_LOCKDEP_KEYS: 8191 [ 0.000000] ... CLASSHASH_SIZE: 4096 [ 0.000000] ... MAX_LOCKDEP_ENTRIES: 16384 [ 0.000000] ... MAX_LOCKDEP_CHAINS: 32768 [ 0.000000] ... CHAINHASH_SIZE: 16384 [ 0.000000] memory used by lock dependency info: 3695 kB [ 0.000000] per task-struct memory footprint: 1152 bytes [ 0.001226] Calibrating delay loop... 364.48 BogoMIPS (lpj=1425408) [ 0.109077] pid_max: default: 32768 minimum: 301 [ 0.109684] Security Framework initialized [ 0.109889] Mount-cache hash table entries: 512 [ 0.122121] CPU: Testing write buffer coherency: ok [ 0.123909] CPU0: thread -1, cpu 0, socket -1, mpidr 0 [ 0.124001] Setting up static identity map for 0x804de288 - 0x804de2f8 [ 0.127162] Brought up 1 CPUs [ 0.127192] SMP: Total of 1 processors activated (364.48 BogoMIPS). [ 0.206604] pinctrl core: initialized pinctrl subsystem [...]
On 12/19/2012 8:48 PM, Bedia, Vaibhav wrote: > I tried out 3 variants of AM335x boards - 2 of these (BeagleBone and EVM) have DDR2 > and 1 has DDR3 (EVM-SK). The BUG is triggered on all of these at the same point. > > With Stephen's change I don't see this on any of the board variants :) > New bootlog below. Great! Can I have your Tested-by then? I'll wrap it up into a patch. Is this is a new regression? From a glance at the code it looks to have existed for quite a while now.
On Thu, Dec 20, 2012 at 11:55:24, Stephen Boyd wrote: > On 12/19/2012 8:48 PM, Bedia, Vaibhav wrote: > > I tried out 3 variants of AM335x boards - 2 of these (BeagleBone and EVM) have DDR2 > > and 1 has DDR3 (EVM-SK). The BUG is triggered on all of these at the same point. > > > > With Stephen's change I don't see this on any of the board variants :) > > New bootlog below. > > Great! Can I have your Tested-by then? I'll wrap it up into a patch. Is > this is a new regression? From a glance at the code it looks to have > existed for quite a while now. I went back to a branch based off 3.7-rc4 and don't see the issue there. Not sure what is triggering this now. Tested-by: Vaibhav Bedia <vaibhav.bedia@ti.com>
On 12/19/2012 10:44 PM, Bedia, Vaibhav wrote: > On Thu, Dec 20, 2012 at 11:55:24, Stephen Boyd wrote: >> On 12/19/2012 8:48 PM, Bedia, Vaibhav wrote: >>> I tried out 3 variants of AM335x boards - 2 of these (BeagleBone and EVM) have DDR2 >>> and 1 has DDR3 (EVM-SK). The BUG is triggered on all of these at the same point. >>> >>> With Stephen's change I don't see this on any of the board variants :) >>> New bootlog below. >> Great! Can I have your Tested-by then? I'll wrap it up into a patch. Is >> this is a new regression? From a glance at the code it looks to have >> existed for quite a while now. > I went back to a branch based off 3.7-rc4 and don't see the issue there. Not sure > what is triggering this now. > > Tested-by: Vaibhav Bedia <vaibhav.bedia@ti.com> Thanks. I was thrown off by the author date of this patch which introduced your problem commit 8823c079ba7136dc1948d6f6dcb5f8022bde438e Author: Eric W. Biederman <ebiederm@xmission.com> AuthorDate: Sun Mar 7 18:49:36 2010 -0800 Commit: Eric W. Biederman <ebiederm@xmission.com> CommitDate: Mon Nov 19 05:59:18 2012 -0800 vfs: Add setns support for the mount namespace It seems to have a 2 year gap between commit date and author date. Either way, it looks to be isolated to the 3.8 merge window but affects quite a few architectures. Patch to follow shortly.
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);