linux/arch
James Morse d8797b1257 arm64: Use a raw spinlock in __install_bp_hardening_cb()
__install_bp_hardening_cb() is called via stop_machine() as part
of the cpu_enable callback. To force each CPU to take its turn
when allocating slots, they take a spinlock.

With the RT patches applied, the spinlock becomes a mutex,
and we get warnings about sleeping while in stop_machine():
| [    0.319176] CPU features: detected: RAS Extension Support
| [    0.319950] BUG: scheduling while atomic: migration/3/36/0x00000002
| [    0.319955] Modules linked in:
| [    0.319958] Preemption disabled at:
| [    0.319969] [<ffff000008181ae4>] cpu_stopper_thread+0x7c/0x108
| [    0.319973] CPU: 3 PID: 36 Comm: migration/3 Not tainted 4.19.1-rt3-00250-g330fc2c2a880 #2
| [    0.319975] Hardware name: linux,dummy-virt (DT)
| [    0.319976] Call trace:
| [    0.319981]  dump_backtrace+0x0/0x148
| [    0.319983]  show_stack+0x14/0x20
| [    0.319987]  dump_stack+0x80/0xa4
| [    0.319989]  __schedule_bug+0x94/0xb0
| [    0.319991]  __schedule+0x510/0x560
| [    0.319992]  schedule+0x38/0xe8
| [    0.319994]  rt_spin_lock_slowlock_locked+0xf0/0x278
| [    0.319996]  rt_spin_lock_slowlock+0x5c/0x90
| [    0.319998]  rt_spin_lock+0x54/0x58
| [    0.320000]  enable_smccc_arch_workaround_1+0xdc/0x260
| [    0.320001]  __enable_cpu_capability+0x10/0x20
| [    0.320003]  multi_cpu_stop+0x84/0x108
| [    0.320004]  cpu_stopper_thread+0x84/0x108
| [    0.320008]  smpboot_thread_fn+0x1e8/0x2b0
| [    0.320009]  kthread+0x124/0x128
| [    0.320010]  ret_from_fork+0x10/0x18

Switch this to a raw spinlock, as we know this is only called with
IRQs masked.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-11-27 18:01:34 +00:00
..
alpha TTY/Serial fixes for 4.20-rc2 2018-11-10 13:32:14 -06:00
arc mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
arm Merge branch 'spectre' of git://git.armlinux.org.uk/~rmk/linux-arm 2018-11-18 10:45:09 -08:00
arm64 arm64: Use a raw spinlock in __install_bp_hardening_cb() 2018-11-27 18:01:34 +00:00
c6x c6x changes for 4.20 2018-10-31 15:39:25 -07:00
csky csky: dtb Kbuild fixup patches for linux-4.20-rc1 2018-11-01 09:04:30 -07:00
h8300 mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
hexagon mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
ia64 memblock: stop using implicit alignment to SMP_CACHE_BYTES 2018-10-31 08:54:16 -07:00
m68k s390 updates for 4.20-rc2 2018-11-09 06:30:44 -06:00
microblaze s390 updates for 4.20-rc2 2018-11-09 06:30:44 -06:00
mips MIPS: Fix `dma_alloc_coherent' returning a non-coherent allocation 2018-11-05 10:08:13 -08:00
nds32 s390 updates for 4.20-rc2 2018-11-09 06:30:44 -06:00
nios2 mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
openrisc mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
parisc Merge branch 'parisc-4.20-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2018-11-14 13:42:41 -06:00
powerpc powerpc/64: Fix kernel stack 16-byte alignment 2018-11-15 14:48:43 +11:00
riscv RISC-V: Silence some module warnings on 32-bit 2018-11-12 18:12:24 -08:00
s390 s390 updates for 4.20-rc2 2018-11-09 06:30:44 -06:00
sh mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
sparc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc 2018-11-01 09:07:04 -07:00
um for-linus-20181109 2018-11-09 16:31:51 -06:00
unicore32 memblock: stop using implicit alignment to SMP_CACHE_BYTES 2018-10-31 08:54:16 -07:00
x86 perf/x86/intel/uncore: Support CoffeeLake 8th CBOX 2018-11-12 05:03:26 +01:00
xtensa Xtensa fixes for v4.20-rc3 2018-11-16 10:10:27 -06:00
.gitignore
Kconfig New gcc plugin: stackleak 2018-11-01 11:46:27 -07:00