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| author | Ming Lei <tom.leiming@gmail.com> | 2011-06-05 02:24:58 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2011-06-06 10:56:22 +0100 |
| commit | 9fc2552a68eb28f95f367156cf46a3da7843ff37 (patch) | |
| tree | 4fb20b6f2506f5503ec55d205af835c65499fe5d | |
| parent | 45f6d7e0e634d49744c1a590461ed1bb3d2201ac (diff) | |
| download | linux-9fc2552a68eb28f95f367156cf46a3da7843ff37.tar.gz linux-9fc2552a68eb28f95f367156cf46a3da7843ff37.tar.bz2 linux-9fc2552a68eb28f95f367156cf46a3da7843ff37.zip | |
ARM: 6952/1: fix lockdep warning of "unannotated irqs-off"
This patch fixes the lockdep warning of "unannotated irqs-off"[1].
After entering __irq_usr, arm core will disable interrupt automatically,
but __irq_usr does not annotate the irq disable, so lockdep may complain
the warning if it has chance to check this in irq handler.
This patch adds trace_hardirqs_off in __irq_usr before entering irq_handler
to handle the irq, also calls ret_to_user_from_irq to avoid calling
disable_irq again.
This is also a fix for irq off tracer.
[1], lockdep warning log of "unannotated irqs-off"
[ 13.804687] ------------[ cut here ]------------
[ 13.809570] WARNING: at kernel/lockdep.c:3335 check_flags+0x78/0x1d0()
[ 13.816467] Modules linked in:
[ 13.819732] Backtrace:
[ 13.822357] [<c01cb42c>] (dump_backtrace+0x0/0x100) from [<c06abb14>] (dump_stack+0x20/0x24)
[ 13.831268] r6:c07d8c2c r5:00000d07 r4:00000000 r3:00000000
[ 13.837280] [<c06abaf4>] (dump_stack+0x0/0x24) from [<c01ffc04>] (warn_slowpath_common+0x5c/0x74)
[ 13.846649] [<c01ffba8>] (warn_slowpath_common+0x0/0x74) from [<c01ffc48>] (warn_slowpath_null+0x2c/0x34)
[ 13.856781] r8:00000000 r7:00000000 r6:c18b8194 r5:60000093 r4:ef182000
[ 13.863708] r3:00000009
[ 13.866485] [<c01ffc1c>] (warn_slowpath_null+0x0/0x34) from [<c0237d84>] (check_flags+0x78/0x1d0)
[ 13.875823] [<c0237d0c>] (check_flags+0x0/0x1d0) from [<c023afc8>] (lock_acquire+0x4c/0x150)
[ 13.884704] [<c023af7c>] (lock_acquire+0x0/0x150) from [<c06af638>] (_raw_spin_lock+0x4c/0x84)
[ 13.893798] [<c06af5ec>] (_raw_spin_lock+0x0/0x84) from [<c01f9a44>] (sched_ttwu_pending+0x58/0x8c)
[ 13.903320] r6:ef92d040 r5:00000003 r4:c18b8180
[ 13.908233] [<c01f99ec>] (sched_ttwu_pending+0x0/0x8c) from [<c01f9a90>] (scheduler_ipi+0x18/0x1c)
[ 13.917663] r6:ef183fb0 r5:00000003 r4:00000000 r3:00000001
[ 13.923645] [<c01f9a78>] (scheduler_ipi+0x0/0x1c) from [<c01bc458>] (do_IPI+0x9c/0xfc)
[ 13.932006] [<c01bc3bc>] (do_IPI+0x0/0xfc) from [<c06b0888>] (__irq_usr+0x48/0xe0)
[ 13.939971] Exception stack(0xef183fb0 to 0xef183ff8)
[ 13.945281] 3fa0: ffffffc3 0001500c 00000001 0001500c
[ 13.953948] 3fc0: 00000050 400b45f0 400d9000 00000000 00000001 400d9600 6474e552 bea05b3c
[ 13.962585] 3fe0: 400d96c0 bea059c0 400b6574 400b65d8 20000010 ffffffff
[ 13.969573] r6:00000403 r5:fa240100 r4:ffffffff r3:20000010
[ 13.975585] ---[ end trace efc4896ab0fb62cb ]---
[ 13.980468] possible reason: unannotated irqs-off.
[ 13.985534] irq event stamp: 1610
[ 13.989044] hardirqs last enabled at (1610): [<c01c703c>] no_work_pending+0x8/0x2c
[ 13.997131] hardirqs last disabled at (1609): [<c01c7024>] ret_slow_syscall+0xc/0x1c
[ 14.005371] softirqs last enabled at (0): [<c01fe5e4>] copy_process+0x2cc/0xa24
[ 14.013183] softirqs last disabled at (0): [< (null)>] (null)
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| -rw-r--r-- | arch/arm/kernel/entry-armv.S | 6 | ||||
| -rw-r--r-- | arch/arm/kernel/entry-common.S | 2 |
2 files changed, 7 insertions, 1 deletions
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index e8d885676807..90c62cd51ca9 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -435,6 +435,10 @@ __irq_usr: usr_entry kuser_cmpxchg_check +#ifdef CONFIG_IRQSOFF_TRACER + bl trace_hardirqs_off +#endif + get_thread_info tsk #ifdef CONFIG_PREEMPT ldr r8, [tsk, #TI_PREEMPT] @ get preempt count @@ -453,7 +457,7 @@ __irq_usr: #endif mov why, #0 - b ret_to_user + b ret_to_user_from_irq UNWIND(.fnend ) ENDPROC(__irq_usr) diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index 1e7b04a40a31..b2a27b6b0046 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -64,6 +64,7 @@ work_resched: ENTRY(ret_to_user) ret_slow_syscall: disable_irq @ disable interrupts +ENTRY(ret_to_user_from_irq) ldr r1, [tsk, #TI_FLAGS] tst r1, #_TIF_WORK_MASK bne work_pending @@ -75,6 +76,7 @@ no_work_pending: arch_ret_to_user r1, lr restore_user_regs fast = 0, offset = 0 +ENDPROC(ret_to_user_from_irq) ENDPROC(ret_to_user) /* |