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authorLinus Torvalds <torvalds@linux-foundation.org>2020-03-20 09:28:25 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-03-20 09:28:25 -0700
commit5ad0ec0b86525d0c5d3d250d3cfad7f183b00cfa (patch)
treee54c76acc4342a68cd3195ba1a6447d07d7df64c
parentf014d2b8584d0bf938e8d6761c79596e94b06f98 (diff)
parent3568b88944fef28db3ee989b957da49ffc627ede (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
-rw-r--r--arch/arm64/include/asm/mmu.h4
-rw-r--r--arch/arm64/include/asm/pgtable-prot.h6
-rw-r--r--arch/arm64/include/asm/unistd.h2
-rw-r--r--arch/arm64/kernel/smp.c25
4 files changed, 26 insertions, 11 deletions
diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h
index e4d862420bb4..d79ce6df9e12 100644
--- a/arch/arm64/include/asm/mmu.h
+++ b/arch/arm64/include/asm/mmu.h
@@ -29,11 +29,9 @@ typedef struct {
*/
#define ASID(mm) ((mm)->context.id.counter & 0xffff)
-extern bool arm64_use_ng_mappings;
-
static inline bool arm64_kernel_unmapped_at_el0(void)
{
- return arm64_use_ng_mappings;
+ return cpus_have_const_cap(ARM64_UNMAP_KERNEL_AT_EL0);
}
typedef void (*bp_hardening_cb_t)(void);
diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h
index 6f87839f0249..1305e28225fc 100644
--- a/arch/arm64/include/asm/pgtable-prot.h
+++ b/arch/arm64/include/asm/pgtable-prot.h
@@ -23,11 +23,13 @@
#include <asm/pgtable-types.h>
+extern bool arm64_use_ng_mappings;
+
#define _PROT_DEFAULT (PTE_TYPE_PAGE | PTE_AF | PTE_SHARED)
#define _PROT_SECT_DEFAULT (PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S)
-#define PTE_MAYBE_NG (arm64_kernel_unmapped_at_el0() ? PTE_NG : 0)
-#define PMD_MAYBE_NG (arm64_kernel_unmapped_at_el0() ? PMD_SECT_NG : 0)
+#define PTE_MAYBE_NG (arm64_use_ng_mappings ? PTE_NG : 0)
+#define PMD_MAYBE_NG (arm64_use_ng_mappings ? PMD_SECT_NG : 0)
#define PROT_DEFAULT (_PROT_DEFAULT | PTE_MAYBE_NG)
#define PROT_SECT_DEFAULT (_PROT_SECT_DEFAULT | PMD_MAYBE_NG)
diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h
index 1dd22da1c3a9..803039d504de 100644
--- a/arch/arm64/include/asm/unistd.h
+++ b/arch/arm64/include/asm/unistd.h
@@ -25,8 +25,8 @@
#define __NR_compat_gettimeofday 78
#define __NR_compat_sigreturn 119
#define __NR_compat_rt_sigreturn 173
-#define __NR_compat_clock_getres 247
#define __NR_compat_clock_gettime 263
+#define __NR_compat_clock_getres 264
#define __NR_compat_clock_gettime64 403
#define __NR_compat_clock_getres_time64 406
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);