linux_dsm_epyc7002/arch/x86
Tahsin Erdogan e8a4a2696f x86/spinlocks: Fix regression in spinlock contention detection
A spinlock is regarded as contended when there is at least one waiter.
Currently, the code that checks whether there are any waiters rely on
tail value being greater than head. However, this is not true if tail
reaches the max value and wraps back to zero, so arch_spin_is_contended()
incorrectly returns 0 (not contended) when tail is smaller than head.

The original code (before regression) handled this case by casting the
(tail - head) to an unsigned value. This change simply restores that
behavior.

Fixes: d6abfdb202 ("x86/spinlocks/paravirt: Fix memory corruption on unlock")
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Cc: peterz@infradead.org
Cc: Waiman.Long@hp.com
Cc: borntraeger@de.ibm.com
Cc: oleg@redhat.com
Cc: raghavendra.kt@linux.vnet.ibm.com
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1430799331-20445-1-git-send-email-tahsin@google.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-05 11:01:38 +02:00
..
boot Merge branch 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-04-13 13:19:10 -07:00
configs x86/build/defconfig: Enable USB_EHCI_TT_NEWSCHED=y 2015-02-19 02:21:14 +01:00
crypto x86/asm: Replace "MOVQ $imm, %reg" with MOVL 2015-04-01 13:17:39 +02:00
ia32 x86/asm/entry: Zero EXTRA_REGS for stub32_execve() too 2015-04-09 10:31:24 +02:00
include x86/spinlocks: Fix regression in spinlock contention detection 2015-05-05 11:01:38 +02:00
kernel x86/fpu: Load xsave pointer *after* initialization 2015-04-17 10:15:47 +02:00
kvm Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-04-13 11:08:28 -07:00
lguest x86/asm/entry/irq: Simplify interrupt dispatch table (IDT) layout 2015-04-08 09:02:13 +02:00
lib Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-04-13 13:16:36 -07:00
math-emu
mm x86/mm: Clean up types in xlate_dev_mem_ptr() 2015-04-20 08:41:37 +02:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-12-10 15:48:20 -05:00
oprofile x86/asm/entry: Change all 'user_mode_vm()' calls to 'user_mode()' 2015-03-23 11:14:17 +01:00
pci Revert "x86/PCI: Refine the way to release PCI IRQ resources" 2015-03-20 14:56:19 +01:00
platform Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-04-13 13:32:35 -07:00
power x86/asm/entry: Rename 'init_tss' to 'cpu_tss' 2015-03-06 08:32:58 +01:00
purgatory Merge branches 'x86-build-for-linus', 'x86-cleanups-for-linus' and 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-12-10 12:35:46 -08:00
realmode Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-02-16 14:58:12 -08:00
syscalls x86/asm/entry/64: Remove stub_iopl 2015-03-10 13:56:10 +01:00
tools x86, build: replace Perl script with Shell script 2015-01-26 13:37:18 -08:00
um x86/asm/entry/64: Remove stub_iopl 2015-03-10 13:56:10 +01:00
vdso Merge branch 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-04-13 13:36:45 -07:00
video
xen Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-04-13 13:16:36 -07:00
.gitignore x86/build: Add arch/x86/purgatory/ make generated files to gitignore 2014-10-09 09:29:46 +02:00
Kbuild
Kconfig config: Enable NEED_DMA_MAP_STATE by default when SWIOTLB is selected 2015-04-18 14:36:49 +02:00
Kconfig.cpu
Kconfig.debug x86/intel/quark: Add Isolated Memory Regions for Quark X1000 2015-02-18 23:22:47 +01:00
Makefile x86/raid6: correctly check for assembler capabilities 2015-02-04 08:35:51 +11:00
Makefile_32.cpu
Makefile.um kbuild: do not add $(call ...) to invoke cc-version or cc-fullversion 2015-01-09 17:25:44 +01:00