diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-03-20 09:28:25 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-03-20 09:28:25 -0700 |
commit | 5ad0ec0b86525d0c5d3d250d3cfad7f183b00cfa (patch) | |
tree | e54c76acc4342a68cd3195ba1a6447d07d7df64c /arch/arm64/kernel/smp.c | |
parent | f014d2b8584d0bf938e8d6761c79596e94b06f98 (diff) | |
parent | 3568b88944fef28db3ee989b957da49ffc627ede (diff) |
Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fixes from Will Deacon:
- Fix panic() when it occurs during secondary CPU startup
- Fix "kpti=off" when KASLR is enabled
- Fix howler in compat syscall table for vDSO clock_getres() fallback
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: compat: Fix syscall number of compat_clock_getres
arm64: kpti: Fix "kpti=off" when KASLR is enabled
arm64: smp: fix crash_smp_send_stop() behaviour
arm64: smp: fix smp_send_stop() behaviour
Diffstat (limited to 'arch/arm64/kernel/smp.c')
-rw-r--r-- | arch/arm64/kernel/smp.c | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index d4ed9a19d8fe..5407bf5d98ac 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -958,11 +958,22 @@ void tick_broadcast(const struct cpumask *mask) } #endif +/* + * The number of CPUs online, not counting this CPU (which may not be + * fully online and so not counted in num_online_cpus()). + */ +static inline unsigned int num_other_online_cpus(void) +{ + unsigned int this_cpu_online = cpu_online(smp_processor_id()); + + return num_online_cpus() - this_cpu_online; +} + void smp_send_stop(void) { unsigned long timeout; - if (num_online_cpus() > 1) { + if (num_other_online_cpus()) { cpumask_t mask; cpumask_copy(&mask, cpu_online_mask); @@ -975,10 +986,10 @@ void smp_send_stop(void) /* Wait up to one second for other CPUs to stop */ timeout = USEC_PER_SEC; - while (num_online_cpus() > 1 && timeout--) + while (num_other_online_cpus() && timeout--) udelay(1); - if (num_online_cpus() > 1) + if (num_other_online_cpus()) pr_warn("SMP: failed to stop secondary CPUs %*pbl\n", cpumask_pr_args(cpu_online_mask)); @@ -1001,7 +1012,11 @@ void crash_smp_send_stop(void) cpus_stopped = 1; - if (num_online_cpus() == 1) { + /* + * If this cpu is the only one alive at this point in time, online or + * not, there are no stop messages to be sent around, so just back out. + */ + if (num_other_online_cpus() == 0) { sdei_mask_local_cpu(); return; } @@ -1009,7 +1024,7 @@ void crash_smp_send_stop(void) cpumask_copy(&mask, cpu_online_mask); cpumask_clear_cpu(smp_processor_id(), &mask); - atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1); + atomic_set(&waiting_for_crash_ipi, num_other_online_cpus()); pr_crit("SMP: stopping secondary CPUs\n"); smp_cross_call(&mask, IPI_CPU_CRASH_STOP); |