linux/arch
Daniel Mentz 18b43e89d2 ARC: Call trace_hardirqs_on() before enabling irqs
trace_hardirqs_on_caller() in lockdep.c expects to be called before, not
after interrupts are actually enabled.

The following comment in kernel/locking/lockdep.c substantiates this
claim:

"
/*
 * We're enabling irqs and according to our state above irqs weren't
 * already enabled, yet we find the hardware thinks they are in fact
 * enabled.. someone messed up their IRQ state tracing.
 */
"

An example can be found in include/linux/irqflags.h:

	do { trace_hardirqs_on(); raw_local_irq_enable(); } while (0)

Without this change, we hit the following DEBUG_LOCKS_WARN_ON.

[    7.760000] ------------[ cut here ]------------
[    7.760000] WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:2711 resume_user_mode_begin+0x48/0xf0
[    7.770000] DEBUG_LOCKS_WARN_ON(!irqs_disabled())
[    7.780000] Modules linked in:
[    7.780000] CPU: 0 PID: 1 Comm: init Not tainted 4.7.0-00003-gc668bb9-dirty #366
[    7.790000]
[    7.790000] Stack Trace:
[    7.790000]   arc_unwind_core.constprop.1+0xa4/0x118
[    7.800000]   warn_slowpath_fmt+0x72/0x158
[    7.800000]   resume_user_mode_begin+0x48/0xf0
[    7.810000] ---[ end trace 6f6a7a8fae20d2f0 ]---

Signed-off-by: Daniel Mentz <danielmentz@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-08-10 10:14:07 -07:00
..
alpha RTC for 4.8 2016-08-05 09:48:22 -04:00
arc ARC: Call trace_hardirqs_on() before enabling irqs 2016-08-10 10:14:07 -07:00
arm * ARM bugfix and MSI injection support 2016-08-06 09:18:21 -04:00
arm64 * ARM bugfix and MSI injection support 2016-08-06 09:18:21 -04:00
avr32 dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
blackfin dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
c6x dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
cris dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
frv RTC for 4.8 2016-08-05 09:48:22 -04:00
h8300 RTC for 4.8 2016-08-05 09:48:22 -04:00
hexagon dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
ia64 RTC for 4.8 2016-08-05 09:48:22 -04:00
m32r mm: do not pass mm_struct into handle_mm_fault 2016-07-26 16:19:19 -07:00
m68k RTC for 4.8 2016-08-05 09:48:22 -04:00
metag Metag architecture changes for v4.8 2016-08-05 08:58:00 -04:00
microblaze dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
mips Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2016-08-06 09:13:11 -04:00
mn10300 RTC for 4.8 2016-08-05 09:48:22 -04:00
nios2 dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
openrisc dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
parisc RTC for 4.8 2016-08-05 09:48:22 -04:00
powerpc RTC for 4.8 2016-08-05 09:48:22 -04:00
s390 dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
score treewide: replace obsolete _refok by __ref 2016-08-02 17:31:41 -04:00
sh These changes improve device tree support (including builtin DTB), add 2016-08-06 09:00:05 -04:00
sparc RTC for 4.8 2016-08-05 09:48:22 -04:00
tile tile: support static_key usage in non-module __exit sections 2016-08-04 08:50:07 -04:00
um Merge branch 'for-linus-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml 2016-08-04 19:37:59 -04:00
unicore32 dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
x86 * ARM bugfix and MSI injection support 2016-08-06 09:18:21 -04:00
xtensa dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
.gitignore
Kconfig Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-08-02 16:37:12 -04:00