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sh: Rework irqflags tracing to fix up CONFIG_PROVE_LOCKING.
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This cleans up the irqflags tracing code quite a bit and ties it
in to various missing callsites that caused an imbalance when
CONFIG_PROVE_LOCKING was enabled.

Previously this was catching on:

 987 #ifdef CONFIG_PROVE_LOCKING
 988     DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled);
 989     DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled);
 990 #endif
 991     retval = -EAGAIN;

with hardirqs being doubly enabled, and subsequently bailing out
with the following call trace:

	Call trace:
	[<88035224>] __lock_acquire+0x616/0x6a6
	[<88015a8c>] do_fork+0xf8/0x2b0
	[<880331ec>] trace_hardirqs_on_caller+0xd4/0x114
	[<88241074>] _spin_unlock_irq+0x20/0x64
	[<88035224>] __lock_acquire+0x616/0x6a6
	[<8800386c>] kernel_thread+0x48/0x70
	[<88024ecc>] ____call_usermodehelper+0x0/0x110
	[<88024ecc>] ____call_usermodehelper+0x0/0x110
	[<88003894>] kernel_thread_helper+0x0/0x14
	[<88024bac>] __call_usermodehelper+0x38/0x70
	[<88025dc0>] worker_thread+0x150/0x274
	[<88035b9c>] lock_release+0x0/0x198
	[<88024b74>] __call_usermodehelper+0x0/0x70
	[<88028cf0>] autoremove_wake_function+0x0/0x30
	[<88028bf2>] kthread+0x3e/0x70
	[<88025c70>] worker_thread+0x0/0x274
	[<8800389c>] kernel_thread_helper+0x8/0x14
	[<88028bb4>] kthread+0x0/0x70
	[<88003894>] kernel_thread_helper+0x0/0x14

Reported-by: Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
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Stuart Menefy authored and Paul Mundt committed Jul 29, 2009
1 parent 82b2422 commit fd78a76
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Showing 5 changed files with 96 additions and 53 deletions.
2 changes: 1 addition & 1 deletion arch/sh/Kconfig.debug
View file
Original file line number Diff line number Diff line change
Expand Up @@ -38,7 +38,7 @@ config EARLY_SCIF_CONSOLE_PORT
default "0xffe00000" if CPU_SUBTYPE_SH7780 || CPU_SUBTYPE_SH7763 || \
CPU_SUBTYPE_SH7722 || CPU_SUBTYPE_SH7366 || \
CPU_SUBTYPE_SH7343
default "0xffea0000" if CPU_SUBTYPE_SH7785
default "0xffeb0000" if CPU_SUBTYPE_SH7785
default "0xffeb0000" if CPU_SUBTYPE_SH7786
default "0xfffe8000" if CPU_SUBTYPE_SH7203
default "0xfffe9800" if CPU_SUBTYPE_SH7206 || CPU_SUBTYPE_SH7263
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72 changes: 72 additions & 0 deletions arch/sh/include/asm/entry-macros.S
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Original file line number Diff line number Diff line change
Expand Up @@ -31,6 +31,78 @@
#endif
.endm

#ifdef CONFIG_TRACE_IRQFLAGS

.macro TRACE_IRQS_ON
mov.l r0, @-r15
mov.l r1, @-r15
mov.l r2, @-r15
mov.l r3, @-r15
mov.l r4, @-r15
mov.l r5, @-r15
mov.l r6, @-r15
mov.l r7, @-r15

mov.l 7834f, r0
jsr @r0
nop

mov.l @r15+, r7
mov.l @r15+, r6
mov.l @r15+, r5
mov.l @r15+, r4
mov.l @r15+, r3
mov.l @r15+, r2
mov.l @r15+, r1
mov.l @r15+, r0
mov.l 7834f, r0

bra 7835f
nop
.balign 4
7834: .long trace_hardirqs_on
7835:
.endm
.macro TRACE_IRQS_OFF

mov.l r0, @-r15
mov.l r1, @-r15
mov.l r2, @-r15
mov.l r3, @-r15
mov.l r4, @-r15
mov.l r5, @-r15
mov.l r6, @-r15
mov.l r7, @-r15

mov.l 7834f, r0
jsr @r0
nop

mov.l @r15+, r7
mov.l @r15+, r6
mov.l @r15+, r5
mov.l @r15+, r4
mov.l @r15+, r3
mov.l @r15+, r2
mov.l @r15+, r1
mov.l @r15+, r0
mov.l 7834f, r0

bra 7835f
nop
.balign 4
7834: .long trace_hardirqs_off
7835:
.endm

#else
.macro TRACE_IRQS_ON
.endm

.macro TRACE_IRQS_OFF
.endm
#endif

#if defined(CONFIG_CPU_SH2A) || defined(CONFIG_CPU_SH4)
# define PREF(x) pref @x
#else
Expand Down
63 changes: 16 additions & 47 deletions arch/sh/kernel/entry-common.S
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Original file line number Diff line number Diff line change
Expand Up @@ -45,7 +45,7 @@
*/

#if defined(CONFIG_PREEMPT)
# define preempt_stop() cli
# define preempt_stop() cli ; TRACE_IRQS_OFF
#else
# define preempt_stop()
# define resume_kernel __restore_all
Expand All @@ -55,34 +55,31 @@
.align 2
ENTRY(exception_error)
!
#ifdef CONFIG_TRACE_IRQFLAGS
mov.l 2f, r0
jsr @r0
nop
#endif
TRACE_IRQS_ON
sti
mov.l 1f, r0
jmp @r0
nop

.align 2
1: .long do_exception_error
#ifdef CONFIG_TRACE_IRQFLAGS
2: .long trace_hardirqs_on
#endif

.align 2
ret_from_exception:
preempt_stop()
#ifdef CONFIG_TRACE_IRQFLAGS
mov.l 4f, r0
jsr @r0
nop
#endif
ENTRY(ret_from_irq)
!
mov #OFF_SR, r0
mov.l @(r0,r15), r0 ! get status register

shlr2 r0
and #0x3c, r0
cmp/eq #0x3c, r0
bt 9f
TRACE_IRQS_ON
9:
mov #OFF_SR, r0
mov.l @(r0,r15), r0 ! get status register
shll r0
shll r0 ! kernel space?
get_current_thread_info r8, r0
Expand Down Expand Up @@ -125,11 +122,7 @@ noresched:
ENTRY(resume_userspace)
! r8: current_thread_info
cli
#ifdef CONFIG_TRACE_IRQFLAGS
mov.l 5f, r0
jsr @r0
nop
#endif
TRACE_IRQS_OfF
mov.l @(TI_FLAGS,r8), r0 ! current_thread_info->flags
tst #(_TIF_WORK_MASK & 0xff), r0
bt/s __restore_all
Expand All @@ -156,11 +149,7 @@ work_resched:
jsr @r1 ! schedule
nop
cli
#ifdef CONFIG_TRACE_IRQFLAGS
mov.l 5f, r0
jsr @r0
nop
#endif
TRACE_IRQS_OFF
!
mov.l @(TI_FLAGS,r8), r0 ! current_thread_info->flags
tst #(_TIF_WORK_MASK & 0xff), r0
Expand All @@ -172,10 +161,6 @@ work_resched:
1: .long schedule
2: .long do_notify_resume
3: .long resume_userspace
#ifdef CONFIG_TRACE_IRQFLAGS
4: .long trace_hardirqs_on
5: .long trace_hardirqs_off
#endif

.align 2
syscall_exit_work:
Expand All @@ -184,11 +169,7 @@ syscall_exit_work:
tst #(_TIF_WORK_SYSCALL_MASK & 0xff), r0
bt/s work_pending
tst #_TIF_NEED_RESCHED, r0
#ifdef CONFIG_TRACE_IRQFLAGS
mov.l 5f, r0
jsr @r0
nop
#endif
TRACE_IRQS_ON
sti
mov r15, r4
mov.l 8f, r0 ! do_syscall_trace_leave
Expand Down Expand Up @@ -321,11 +302,7 @@ ENTRY(system_call)
bt/s debug_trap ! it's a debug trap..
nop

#ifdef CONFIG_TRACE_IRQFLAGS
mov.l 5f, r10
jsr @r10
nop
#endif
TRACE_IRQS_ON
sti

!
Expand Down Expand Up @@ -355,11 +332,7 @@ syscall_call:
!
syscall_exit:
cli
#ifdef CONFIG_TRACE_IRQFLAGS
mov.l 6f, r0
jsr @r0
nop
#endif
TRACE_IRQS_OFF
!
get_current_thread_info r8, r0
mov.l @(TI_FLAGS,r8), r0 ! current_thread_info->flags
Expand All @@ -377,9 +350,5 @@ syscall_exit:
#endif
2: .long NR_syscalls
3: .long sys_call_table
#ifdef CONFIG_TRACE_IRQFLAGS
5: .long trace_hardirqs_on
6: .long trace_hardirqs_off
#endif
7: .long do_syscall_trace_enter
8: .long do_syscall_trace_leave
7 changes: 4 additions & 3 deletions arch/sh/kernel/io_trapped.c
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Original file line number Diff line number Diff line change
Expand Up @@ -112,22 +112,23 @@ void __iomem *match_trapped_io_handler(struct list_head *list,
struct trapped_io *tiop;
struct resource *res;
int k, len;
unsigned long flags;

spin_lock_irq(&trapped_lock);
spin_lock_irqsave(&trapped_lock, flags);
list_for_each_entry(tiop, list, list) {
voffs = 0;
for (k = 0; k < tiop->num_resources; k++) {
res = tiop->resource + k;
if (res->start == offset) {
spin_unlock_irq(&trapped_lock);
spin_unlock_irqrestore(&trapped_lock, flags);
return tiop->virt_base + voffs;
}

len = (res->end - res->start) + 1;
voffs += roundup(len, PAGE_SIZE);
}
}
spin_unlock_irq(&trapped_lock);
spin_unlock_irqrestore(&trapped_lock, flags);
return NULL;
}
EXPORT_SYMBOL_GPL(match_trapped_io_handler);
Expand Down
5 changes: 3 additions & 2 deletions drivers/serial/sh-sci.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -662,10 +662,11 @@ static irqreturn_t sci_rx_interrupt(int irq, void *port)
static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
{
struct uart_port *port = ptr;
unsigned long flags;

spin_lock_irq(&port->lock);
spin_lock_irqsave(&port->lock, flags);
sci_transmit_chars(port);
spin_unlock_irq(&port->lock);
spin_unlock_irqrestore(&port->lock, flags);

return IRQ_HANDLED;
}
Expand Down

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