linux_dsm_epyc7002/arch
Matt Redfearn 8f46cca1e6 MIPS: SMP: Fix possibility of deadlock when bringing CPUs online
This patch fixes the possibility of a deadlock when bringing up
secondary CPUs.
The deadlock occurs because the set_cpu_online() is called before
synchronise_count_slave(). This can cause a deadlock if the boot CPU,
having scheduled another thread, attempts to send an IPI to the
secondary CPU, which it sees has been marked online. The secondary is
blocked in synchronise_count_slave() waiting for the boot CPU to enter
synchronise_count_master(), but the boot cpu is blocked in
smp_call_function_many() waiting for the secondary to respond to it's
IPI request.

Fix this by marking the CPU online in cpu_callin_map and synchronising
counters before declaring the CPU online and calculating the maps for
IPIs.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reported-by: Justin Chen <justinpopo6@gmail.com>
Tested-by: Justin Chen <justinpopo6@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: stable@vger.kernel.org # v4.1+
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14302/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-09-25 01:43:52 +02:00
..
alpha RTC for 4.8 2016-08-05 09:48:22 -04:00
arc ARC: export __udivdi3 for modules 2016-08-19 14:09:33 -07:00
arm Merge branch 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm 2016-09-09 08:32:10 -07:00
arm64 arm64: use preempt_disable_notrace in _percpu_read/write 2016-09-09 12:34:47 +01:00
avr32 dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
blackfin net: smc91x: fix SMC accesses 2016-08-28 23:44:55 -04:00
c6x dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
cris dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
frv RTC for 4.8 2016-08-05 09:48:22 -04:00
h8300 h8300: Add missing include file to asm/io.h 2016-08-13 08:53:56 -07:00
hexagon dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
ia64 usercopy: fold builtin_const check into inline function 2016-09-06 12:17:29 -07:00
m32r mm: do not pass mm_struct into handle_mm_fault 2016-07-26 16:19:19 -07:00
m68k m68knommu: fix user a5 register being overwritten 2016-08-08 12:38:47 +10:00
metag metag: Drop show_mem() from mem_init() 2016-08-09 13:41:30 +01:00
microblaze dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
mips MIPS: SMP: Fix possibility of deadlock when bringing CPUs online 2016-09-25 01:43:52 +02:00
mn10300 RTC for 4.8 2016-08-05 09:48:22 -04:00
nios2 dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
openrisc dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
parisc mm/usercopy: get rid of CONFIG_DEBUG_STRICT_USER_COPY_CHECKS 2016-08-30 10:10:21 -07:00
powerpc powerpc fixes for 4.8 #5 2016-09-09 08:43:42 -07:00
s390 mm/usercopy: get rid of CONFIG_DEBUG_STRICT_USER_COPY_CHECKS 2016-08-30 10:10:21 -07:00
score treewide: replace obsolete _refok by __ref 2016-08-02 17:31:41 -04:00
sh These changes improve device tree support (including builtin DTB), add 2016-08-06 09:00:05 -04:00
sparc usercopy: fold builtin_const check into inline function 2016-09-06 12:17:29 -07:00
tile mm/usercopy: get rid of CONFIG_DEBUG_STRICT_USER_COPY_CHECKS 2016-08-30 10:10:21 -07:00
um um/ptrace: Fix the syscall number update after a ptrace 2016-09-07 09:25:04 -07:00
unicore32 unicore32: mm: Add missing parameter to arch_vma_access_permitted 2016-08-13 08:53:18 -07:00
x86 Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm 2016-09-10 09:58:52 -07:00
xtensa dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
.gitignore
Kconfig seccomp: Remove 2-phase API documentation 2016-09-07 09:25:05 -07:00