sh: Rework irqflags tracing to fix up CONFIG_PROVE_LOCKING.
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>
diff --git a/arch/sh/kernel/io_trapped.c b/arch/sh/kernel/io_trapped.c
index 77dfecb..e27a19e 100644
--- a/arch/sh/kernel/io_trapped.c
+++ b/arch/sh/kernel/io_trapped.c
@@ -112,14 +112,15 @@
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;
}
@@ -127,7 +128,7 @@
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);