Messages in this thread | | | From | Petr Mladek <> | Subject | [PATCH v4 0/4] Cleaning printk stuff in NMI context | Date | Fri, 11 Dec 2015 14:20:48 +0100 |
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Hi Andrew,
this is just a quick respin of the previous version. It changes the few details as you suggested. Also it fixes the build problem on ARM as reported by Geert and Arnd.
I rather send the whole patch set because there is the renamed header. Also the extra blank space affects two patches. I hope that it will safe you some work. Please, let me know if you would prefer incremental patches.
Changes against v3:
+ used size_t for "len" and "size"
+ replaced WARN() with pr_err()
+ renamed kernel/printk/printk.h -> internal.h
+ fixed build on ARM (undefined NMI_LOG_BUF_SHIFT)
Changes against v2:
+ fixed compilation problems reported by 0-day build robot
+ MN10300 and Xtensa architectures will get handled separately
+ dropped the patch that printed NMI messages directly when Oops in progress; it made the solution less reliable
+ made the size of the buffer configurable; use real numbers instead of PAGE_SIZE
Changes against v1:
+ rebased on top of 4.4-rc2; there the old implementation was moved to lib/nmi_backtrace.c and used also on arm; I hope that I got the arm side correctly; I was not able to test on arm :-(
+ defined HAVE_NMI on arm for !CPU_V7M instead of !CPU_V7; handle_fiq_as_nmi() is called from entry-armv.S that is compiled when !CPU_V7M
+ defined HAVE_NMI also on mips; it calls nmi_enter() and seems to have real NMIs (or am I wrong?)
+ serialized backtraces when printing directly (oops_in_progress)
Petr Mladek (4): printk/nmi: Generic solution for safe printk in NMI printk/nmi: Use IRQ work only when ready printk/nmi: Warn when some message has been lost in NMI context printk/nmi: Increase the size of NMI buffer and make it configurable
arch/Kconfig | 7 ++ arch/arm/Kconfig | 2 + arch/arm/kernel/smp.c | 2 + arch/avr32/Kconfig | 1 + arch/blackfin/Kconfig | 1 + arch/cris/Kconfig | 1 + arch/mips/Kconfig | 1 + arch/powerpc/Kconfig | 1 + arch/s390/Kconfig | 1 + arch/sh/Kconfig | 1 + arch/sparc/Kconfig | 1 + arch/tile/Kconfig | 1 + arch/x86/Kconfig | 1 + arch/x86/kernel/apic/hw_nmi.c | 1 - include/linux/hardirq.h | 2 + include/linux/percpu.h | 3 - include/linux/printk.h | 12 ++- init/Kconfig | 27 +++++ init/main.c | 1 + kernel/printk/Makefile | 1 + kernel/printk/internal.h | 55 +++++++++++ kernel/printk/nmi.c | 222 ++++++++++++++++++++++++++++++++++++++++++ kernel/printk/printk.c | 29 +++--- lib/nmi_backtrace.c | 89 +---------------- 24 files changed, 356 insertions(+), 107 deletions(-) create mode 100644 kernel/printk/internal.h create mode 100644 kernel/printk/nmi.c
-- 1.8.5.6
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