kernel/linux.git/arch/cris/Kconfig, branch linux-4.7.y

printk/nmi: generic solution for safe printk in NMI

2016-05-21T00:58:30+00:00

printk() takes some locks and could not be used a safe way in NMI context. The chance of a deadlock is real especially when printing stacks from all CPUs. This particular problem has been addressed on x86 by the commit a9edc8809328 ("x86/nmi: Perform a safe NMI stack trace on all CPUs"). The patchset brings two big advantages. First, it makes the NMI backtraces safe on all architectures for free. Second, it makes all NMI messages almost safe on all architectures (the temporary buffer is limited. We still should keep the number of messages in NMI context at minimum). Note that there already are several messages printed in NMI context: WARN_ON(in_nmi()), BUG_ON(in_nmi()), anything being printed out from MCE handlers. These are not easy to avoid. This patch reuses most of the code and makes it generic. It is useful for all messages and architectures that support NMI. The alternative printk_func is set when entering and is reseted when leaving NMI context. It queues IRQ work to copy the messages into the main ring buffer in a safe context. __printk_nmi_flush() copies all available messages and reset the buffer. Then we could use a simple cmpxchg operations to get synchronized with writers. There is also used a spinlock to get synchronized with other flushers. We do not longer use seq_buf because it depends on external lock. It would be hard to make all supported operations safe for a lockless use. It would be confusing and error prone to make only some operations safe. The code is put into separate printk/nmi.c as suggested by Steven Rostedt. It needs a per-CPU buffer and is compiled only on architectures that call nmi_enter(). This is achieved by the new HAVE_NMI Kconfig flag. The are MN10300 and Xtensa architectures. We need to clean up NMI handling there first. Let's do it separately. The patch is heavily based on the draft from Peter Zijlstra, see https://lkml.org/lkml/2015/6/10/327 [arnd@arndb.de: printk-nmi: use %zu format string for size_t] [akpm@linux-foundation.org: min_t->min - all types are size_t here] Signed-off-by: Petr Mladek Suggested-by: Peter Zijlstra Suggested-by: Steven Rostedt Cc: Jan Kara Acked-by: Russell King [arm part] Cc: Daniel Thompson Cc: Jiri Kosina Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Ralf Baechle Cc: Benjamin Herrenschmidt Cc: Martin Schwidefsky Cc: David Miller Cc: Daniel Thompson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

exit_thread: remove empty bodies

2016-05-21T00:58:30+00:00

Define HAVE_EXIT_THREAD for archs which want to do something in exit_thread. For others, let's define exit_thread as an empty inline. This is a cleanup before we change the prototype of exit_thread to accept a task parameter. [akpm@linux-foundation.org: fix mips] Signed-off-by: Jiri Slaby Cc: "David S. Miller" Cc: "H. Peter Anvin" Cc: "James E.J. Bottomley" Cc: Aurelien Jacquiot Cc: Benjamin Herrenschmidt Cc: Catalin Marinas Cc: Chen Liqin Cc: Chris Metcalf Cc: Chris Zankel Cc: David Howells Cc: Fenghua Yu Cc: Geert Uytterhoeven Cc: Guan Xuetao Cc: Haavard Skinnemoen Cc: Hans-Christian Egtvedt Cc: Heiko Carstens Cc: Helge Deller Cc: Ingo Molnar Cc: Ivan Kokshaysky Cc: James Hogan Cc: Jeff Dike Cc: Jesper Nilsson Cc: Jiri Slaby Cc: Jonas Bonn Cc: Koichi Yasutake Cc: Lennox Wu Cc: Ley Foon Tan Cc: Mark Salter Cc: Martin Schwidefsky Cc: Matt Turner Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Simek Cc: Mikael Starvik Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Ralf Baechle Cc: Rich Felker Cc: Richard Henderson Cc: Richard Kuo Cc: Richard Weinberger Cc: Russell King Cc: Steven Miao Cc: Thomas Gleixner Cc: Tony Luck Cc: Vineet Gupta Cc: Will Deacon Cc: Yoshinori Sato Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

cris: do away with ARCH_REQUIRE_GPIOLIB

2016-04-26T12:04:10+00:00

Replace "select ARCH_REQUIRE_GPIOLIB" with "select GPIOLIB" as this can now be selected directly. Cc: Michael Büsch Cc: Mikael Starvik Cc: linux-cris-kernel@axis.com Acked-by: Jesper Nilsson Signed-off-by: Linus Walleij

cris: time: Cleanup of persistent clock stuff

2015-11-02T19:03:05+00:00

- Remove update_persistent_clock(), as it does nothing now. - Remove read_persistent_clock(), let it fall back to the weak version. Cc: Mikael Starvik Cc: John Stultz Cc: Arnd Bergmann Signed-off-by: Xunlei Pang Acked-by: Rabin Vincent Signed-off-by: Jesper Nilsson

CRISv32: enable LOCKDEP_SUPPORT

2015-09-04T22:56:50+00:00

Now that we have stack tracing and irq flags tracing support, we can also enable lockdep support Signed-off-by: Rabin Vincent Signed-off-by: Jesper Nilsson

CRIS: add STACKTRACE_SUPPORT

2015-09-04T22:56:50+00:00

Add stacktrace support, which is required for lockdep and tracing. The stack tracing simply looks at all kernel text symbols found on the stack, similar to the trap stack dumping code, which can also be converted to use this. Signed-off-by: Rabin Vincent Signed-off-by: Jesper Nilsson

CRISv32: add support for irqflags tracing

2015-09-04T22:56:49+00:00

Add support irqflags tracing, which is required for things like lockdep and ftrace. Signed-off-by: Rabin Vincent Signed-off-by: Jesper Nilsson

CRISv32: allow CONFIG_DEBUG_BUGVERBOSE

2015-09-04T22:33:25+00:00

Support for verbose BUG reporting already exists, but the HAVE flag that allows the option to be enabled is missing. Signed-off-by: Rabin Vincent Signed-off-by: Jesper Nilsson

CRISv32: use GENERIC_SCHED_CLOCK

2015-03-25T10:03:41+00:00

Provide a fast sched clock using the free-running timer and the generic sched_clock infrastructure. Signed-off-by: Rabin Vincent Signed-off-by: Jesper Nilsson

CRISv32: use MMIO clocksource

2015-03-25T10:03:40+00:00

Use a generic MMIO clocksource and get rid of some lines of code. Signed-off-by: Rabin Vincent Signed-off-by: Jesper Nilsson