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authorIngo Molnar <mingo@kernel.org>2017-08-29 13:10:35 +0200
committerIngo Molnar <mingo@kernel.org>2017-08-29 13:10:35 +0200
commit7b3d61cc73a1abe4c2c7eaf00093b338c8b233b0 (patch)
tree3bbb8f3a1c037f19886cb6e07bb3978cd8a6a92d
parent30d6e0a4190d37740e9447e4e4815f06992dd8c3 (diff)
locking/refcounts, x86/asm: Disable CONFIG_ARCH_HAS_REFCOUNT for the time being
Mike Galbraith bisected a boot crash back to the following commit: 7a46ec0e2f48 ("locking/refcounts, x86/asm: Implement fast refcount overflow protection") The crash/hang pattern is: > Symptom is a few splats as below, with box finally hanging. Network > comes up, but neither ssh nor console login is possible. > > ------------[ cut here ]------------ > WARNING: CPU: 4 PID: 0 at net/netlink/af_netlink.c:374 netlink_sock_destruct+0x82/0xa0 > ... > __sk_destruct() > rcu_process_callbacks() > __do_softirq() > irq_exit() > smp_apic_timer_interrupt() > apic_timer_interrupt() We are at -rc7 already, and the code has grown some dependencies, so instead of a plain revert disable the config temporarily, in the hope of getting real fixes. Reported-by: Mike Galbraith <efault@gmx.de> Tested-by: Mike Galbraith <efault@gmx.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Elena Reshetova <elena.reshetova@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/tip-7a46ec0e2f4850407de5e1d19a44edee6efa58ec@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--arch/x86/Kconfig3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 6e01f585d57c..efd9df53b9e7 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -55,7 +55,8 @@ config X86
select ARCH_HAS_KCOV if X86_64
select ARCH_HAS_MMIO_FLUSH
select ARCH_HAS_PMEM_API if X86_64
- select ARCH_HAS_REFCOUNT
+ # Causing hangs/crashes, see the commit that added this change for details.
+ select ARCH_HAS_REFCOUNT if BROKEN
select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
select ARCH_HAS_SET_MEMORY
select ARCH_HAS_SG_CHAIN