| Message ID | 1450644757-18734-5-git-send-email-daniel.thompson@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Daniel,
[auto build test ERROR on v4.4-rc5]
[also build test ERROR on next-20151218]
[cannot apply to tip/irq/core]
url: https://github.com/0day-ci/linux/commits/Daniel-Thompson/irq-arm-Use-FIQ-for-NMI-backtrace-when-possible/20151221-045854
config: arm-iop-adma (attached as .config)
reproduce:
wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=arm
All errors (new ones prefixed by >>):
arch/arm/kernel/traps.c: In function 'handle_fiq_as_nmi':
>> arch/arm/kernel/traps.c:489:2: error: implicit declaration of function 'handle_arch_irq' [-Werror=implicit-function-declaration]
handle_arch_irq(regs);
^
cc1: some warnings being treated as errors
vim +/handle_arch_irq +489 arch/arm/kernel/traps.c
483 * Either the interrupt controller supports FIQ, meaning it will
484 * do the right thing with this call, or we will end up treating a
485 * spurious FIQ (which is normally fatal) as though it were an IRQ
486 * which, although it risks deadlock, still gives us a sporting
487 * chance of surviving long enough to log errors.
488 */
> 489 handle_arch_irq(regs);
490
491 nmi_exit();
492
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
Hi Daniel,
[auto build test ERROR on v4.4-rc5]
[also build test ERROR on next-20151218]
[cannot apply to tip/irq/core]
url: https://github.com/0day-ci/linux/commits/Daniel-Thompson/irq-arm-Use-FIQ-for-NMI-backtrace-when-possible/20151221-045854
config: arm-socfpga_defconfig (attached as .config)
reproduce:
wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=arm
All error/warnings (new ones prefixed by >>):
In file included from include/uapi/linux/stddef.h:1:0,
from include/linux/stddef.h:4,
from include/uapi/linux/posix_types.h:4,
from include/uapi/linux/types.h:13,
from include/linux/types.h:5,
from include/linux/list.h:4,
from include/linux/module.h:9,
from arch/arm/kernel/smp.c:10:
arch/arm/kernel/smp.c: In function 'raise_nmi':
>> include/linux/compiler.h:484:38: error: call to '__compiletime_assert_766' declared with attribute error: BUILD_BUG_ON failed: SMP_IPI_FIQ_MASK != BIT(IPI_CPU_BACKTRACE)
_compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
^
include/linux/compiler.h:467:4: note: in definition of macro '__compiletime_assert'
prefix ## suffix(); \
^
include/linux/compiler.h:484:2: note: in expansion of macro '_compiletime_assert'
_compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
^
include/linux/bug.h:50:37: note: in expansion of macro 'compiletime_assert'
#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
^
include/linux/bug.h:74:2: note: in expansion of macro 'BUILD_BUG_ON_MSG'
BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
^
>> arch/arm/kernel/smp.c:766:2: note: in expansion of macro 'BUILD_BUG_ON'
BUILD_BUG_ON(SMP_IPI_FIQ_MASK != BIT(IPI_CPU_BACKTRACE));
^
vim +/__compiletime_assert_766 +484 include/linux/compiler.h
9a8ab1c3 Daniel Santos 2013-02-21 478 *
9a8ab1c3 Daniel Santos 2013-02-21 479 * In tradition of POSIX assert, this macro will break the build if the
9a8ab1c3 Daniel Santos 2013-02-21 480 * supplied condition is *false*, emitting the supplied error message if the
9a8ab1c3 Daniel Santos 2013-02-21 481 * compiler has support to do so.
9a8ab1c3 Daniel Santos 2013-02-21 482 */
9a8ab1c3 Daniel Santos 2013-02-21 483 #define compiletime_assert(condition, msg) \
9a8ab1c3 Daniel Santos 2013-02-21 @484 _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
9a8ab1c3 Daniel Santos 2013-02-21 485
47933ad4 Peter Zijlstra 2013-11-06 486 #define compiletime_assert_atomic_type(t) \
47933ad4 Peter Zijlstra 2013-11-06 487 compiletime_assert(__native_word(t), \
:::::: The code at line 484 was first introduced by commit
:::::: 9a8ab1c39970a4938a72d94e6fd13be88a797590 bug.h, compiler.h: introduce compiletime_assert & BUILD_BUG_ON_MSG
:::::: TO: Daniel Santos <daniel.santos@pobox.com>
:::::: CC: Linus Torvalds <torvalds@linux-foundation.org>
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
On 20/12/15 22:12, kbuild test robot wrote: > Hi Daniel, > > [auto build test ERROR on v4.4-rc5] > [also build test ERROR on next-20151218] > [cannot apply to tip/irq/core] > > url: https://github.com/0day-ci/linux/commits/Daniel-Thompson/irq-arm-Use-FIQ-for-NMI-backtrace-when-possible/20151221-045854 > config: arm-iop-adma (attached as .config) > reproduce: > wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross > chmod +x ~/bin/make.cross > # save the attached .config to linux build tree > make.cross ARCH=arm > > All errors (new ones prefixed by >>): > > arch/arm/kernel/traps.c: In function 'handle_fiq_as_nmi': >>> arch/arm/kernel/traps.c:489:2: error: implicit declaration of function 'handle_arch_irq' [-Werror=implicit-function-declaration] > handle_arch_irq(regs); > ^ > cc1: some warnings being treated as errors Thanks. I'll look at this. > vim +/handle_arch_irq +489 arch/arm/kernel/traps.c > > 483 * Either the interrupt controller supports FIQ, meaning it will > 484 * do the right thing with this call, or we will end up treating a > 485 * spurious FIQ (which is normally fatal) as though it were an IRQ > 486 * which, although it risks deadlock, still gives us a sporting > 487 * chance of surviving long enough to log errors. > 488 */ > > 489 handle_arch_irq(regs); > 490 > 491 nmi_exit(); > 492 > > --- > 0-DAY kernel test infrastructure Open Source Technology Center > https://lists.01.org/pipermail/kbuild-all Intel Corporation >
On 20/12/15 22:52, kbuild test robot wrote: > Hi Daniel, > > [auto build test ERROR on v4.4-rc5] > [also build test ERROR on next-20151218] > [cannot apply to tip/irq/core] > > url: https://github.com/0day-ci/linux/commits/Daniel-Thompson/irq-arm-Use-FIQ-for-NMI-backtrace-when-possible/20151221-045854 > config: arm-socfpga_defconfig (attached as .config) > reproduce: > wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross > chmod +x ~/bin/make.cross > # save the attached .config to linux build tree > make.cross ARCH=arm > > All error/warnings (new ones prefixed by >>): > > In file included from include/uapi/linux/stddef.h:1:0, > from include/linux/stddef.h:4, > from include/uapi/linux/posix_types.h:4, > from include/uapi/linux/types.h:13, > from include/linux/types.h:5, > from include/linux/list.h:4, > from include/linux/module.h:9, > from arch/arm/kernel/smp.c:10: > arch/arm/kernel/smp.c: In function 'raise_nmi': >>> include/linux/compiler.h:484:38: error: call to '__compiletime_assert_766' declared with attribute error: BUILD_BUG_ON failed: SMP_IPI_FIQ_MASK != BIT(IPI_CPU_BACKTRACE) > _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__) > ^ > include/linux/compiler.h:467:4: note: in definition of macro '__compiletime_assert' > prefix ## suffix(); \ > ^ > include/linux/compiler.h:484:2: note: in expansion of macro '_compiletime_assert' > _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__) > ^ > include/linux/bug.h:50:37: note: in expansion of macro 'compiletime_assert' > #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) > ^ > include/linux/bug.h:74:2: note: in expansion of macro 'BUILD_BUG_ON_MSG' > BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition) > ^ >>> arch/arm/kernel/smp.c:766:2: note: in expansion of macro 'BUILD_BUG_ON' > BUILD_BUG_ON(SMP_IPI_FIQ_MASK != BIT(IPI_CPU_BACKTRACE)); This should be a false alarm or at least, the BUILD_BUG_ON() is doing exactly what it was intended to. I forgot to mention it in the covering letter (and will fix next time) but my patchset requires a fix from Marc Zyngier which changes the numeric value of IPI_CPU_BACKTRACE[1]. Daniel. 1: http://thread.gmane.org/gmane.linux.ports.arm.kernel/464985
diff --git a/arch/arm/include/asm/smp.h b/arch/arm/include/asm/smp.h index 3d6dc8b460e4..daf869cff02e 100644 --- a/arch/arm/include/asm/smp.h +++ b/arch/arm/include/asm/smp.h @@ -18,6 +18,15 @@ # error "<asm/smp.h> included in non-SMP build" #endif +/* + * Identify which IPIs are safe for the irqchip to handle using FIQ. + * + * This information is advisory. The interrupt controller may not be capable + * of routing these IPIs to FIQ and the kernel will continue to work if they + * are routed to IRQ as normal. + */ +#define SMP_IPI_FIQ_MASK 0x80 + #define raw_smp_processor_id() (current_thread_info()->cpu) struct seq_file; diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index fe517f1e88d8..853089e1aa8a 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -639,6 +639,11 @@ void handle_IPI(int ipinr, struct pt_regs *regs) break; case IPI_CPU_BACKTRACE: + if (in_nmi()) { + nmi_cpu_backtrace(regs); + break; + } + irq_enter(); nmi_cpu_backtrace(regs); irq_exit(); @@ -750,6 +755,7 @@ static void raise_nmi(cpumask_t *mask) if (cpumask_test_cpu(smp_processor_id(), mask) && irqs_disabled()) nmi_cpu_backtrace(NULL); + BUILD_BUG_ON(SMP_IPI_FIQ_MASK != BIT(IPI_CPU_BACKTRACE)); smp_cross_call(mask, IPI_CPU_BACKTRACE); } diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index bc698383e822..a04426ee7684 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -479,7 +479,14 @@ asmlinkage void __exception_irq_entry handle_fiq_as_nmi(struct pt_regs *regs) nmi_enter(); - /* nop. FIQ handlers for special arch/arm features can be added here. */ + /* + * Either the interrupt controller supports FIQ, meaning it will + * do the right thing with this call, or we will end up treating a + * spurious FIQ (which is normally fatal) as though it were an IRQ + * which, although it risks deadlock, still gives us a sporting + * chance of surviving long enough to log errors. + */ + handle_arch_irq(regs); nmi_exit();
The GIC (v1 & v2) driver allows its implementation of handle_arch_irq() to be called from the FIQ handler but currently the ARM code is not able to exploit this. Extend handle_fiq_as_nmi() to call handle_arch_irq(). This will affect all interrupt controllers, including ones that do not support FIQ. This is OK because a spurious FIQ is normally fatal. Handling a spurious FIQ like a normal interrupt does risk deadlock but does give us a chance of surviving long enough to get an error message out. We also extend the SMP code to indicate to irq drivers which IPIs they should seek to implement using FIQ. Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> --- arch/arm/include/asm/smp.h | 9 +++++++++ arch/arm/kernel/smp.c | 6 ++++++ arch/arm/kernel/traps.c | 9 ++++++++- 3 files changed, 23 insertions(+), 1 deletion(-)