From: Ionela Voinescu <ionela.voinescu@arm.com> mainline inclusion from mainline-v5.11-rc1 commit 74490422522d category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I4QGH5 CVE: NA ---------------------- 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> Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Reviewed-by: Hanjun Guo <guohanjun@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- arch/arm64/kernel/topology.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c index f8d9ddc38550..6f1a8edd79ef 100644 --- a/arch/arm64/kernel/topology.c +++ b/arch/arm64/kernel/topology.c @@ -356,9 +356,16 @@ 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; -- 2.20.1