From: Mårten Lindahl <marten.lindahl@axis.com> mainline inclusion from mainline-v6.6-rc1 commit 8922ba71c969d2a0c01a94372a71477d879470de category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/7877 CVE: CVE-2023-53712 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- If a panic is triggered by a hrtimer interrupt all online cpus will be notified and set offline. But as highlighted by commit 19dbdcb8039c ("smp: Warn on function calls from softirq context") this call should not be made synchronous with disabled interrupts: softdog: Initiating panic Kernel panic - not syncing: Software Watchdog Timer expired WARNING: CPU: 1 PID: 0 at kernel/smp.c:753 smp_call_function_many_cond unwind_backtrace: show_stack dump_stack_lvl __warn warn_slowpath_fmt smp_call_function_many_cond smp_call_function crash_smp_send_stop.part.0 machine_crash_shutdown __crash_kexec panic softdog_fire __hrtimer_run_queues hrtimer_interrupt Make the smp call for machine_crash_nonpanic_core() asynchronous. Signed-off-by: Mårten Lindahl <marten.lindahl@axis.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Conflicts: arch/arm/kernel/machine_kexec.c [just context conflicts] Signed-off-by: Liu Mingrui <liumingrui@huawei.com> Signed-off-by: Mingrui Liu <liumingrui@huawei.com> --- arch/arm/kernel/machine_kexec.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/arch/arm/kernel/machine_kexec.c b/arch/arm/kernel/machine_kexec.c index 91045135aadd..ba2dfbd21580 100644 --- a/arch/arm/kernel/machine_kexec.c +++ b/arch/arm/kernel/machine_kexec.c @@ -93,16 +93,28 @@ void machine_crash_nonpanic_core(void *unused) } } +static DEFINE_PER_CPU(call_single_data_t, cpu_stop_csd) = + CSD_INIT(machine_crash_nonpanic_core, NULL); + void crash_smp_send_stop(void) { static int cpus_stopped; unsigned long msecs; + call_single_data_t *csd; + int cpu, this_cpu = raw_smp_processor_id(); if (cpus_stopped) return; atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1); - smp_call_function(machine_crash_nonpanic_core, NULL, false); + for_each_online_cpu(cpu) { + if (cpu == this_cpu) + continue; + + csd = &per_cpu(cpu_stop_csd, cpu); + smp_call_function_single_async(cpu, csd); + } + msecs = 1000; /* Wait at most a second for the other cpus to stop */ while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) { mdelay(1); -- 2.34.1