diff options
| author | Ionela Voinescu <ionela.voinescu@arm.com> | 2020-11-13 15:53:28 +0000 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2020-11-13 20:14:58 +0000 |
| commit | 74490422522d125451cac400fce5d4e6bb9e1fea (patch) | |
| tree | b1915773f92d428989e2923a05c8348fc99c233c /arch/arm64/kernel | |
| parent | 68c5debcc06d6d24f15dbf978780fc5efc147d5e (diff) | |
arm64: abort counter_read_on_cpu() when irqs_disabled()
Given that smp_call_function_single() can deadlock when interrupts are
disabled, abort the SMP call if irqs_disabled(). This scenario is
currently not possible given the function's uses, but safeguard this for
potential future uses.
Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com>
Cc: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20201113155328.4194-1-ionela.voinescu@arm.com
[catalin.marinas@arm.com: modified following Mark's comment]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel')
| -rw-r--r-- | arch/arm64/kernel/topology.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c index 7c9b6a0ecd6a..b8026ec684ba 100644 --- a/arch/arm64/kernel/topology.c +++ b/arch/arm64/kernel/topology.c @@ -343,9 +343,16 @@ static void cpu_read_constcnt(void *val) static inline int counters_read_on_cpu(int cpu, smp_call_func_t func, u64 *val) { + /* + * Abort call on counterless CPU or when interrupts are + * disabled - can lead to deadlock in smp sync call. + */ if (!cpu_has_amu_feat(cpu)) return -EOPNOTSUPP; + if (WARN_ON_ONCE(irqs_disabled())) + return -EPERM; + smp_call_function_single(cpu, func, val, 1); return 0; |