8 files changed, 66 insertions, 34 deletions

diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index ad8aebb1cdef..3dca15634e69 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -270,6 +270,7 @@ static int fpsimd_cpu_pm_notifier(struct notifier_block *self,
 	case CPU_PM_ENTER:
 		if (current->mm && !test_thread_flag(TIF_FOREIGN_FPSTATE))
 			fpsimd_save_state(&current->thread.fpsimd_state);
+		this_cpu_write(fpsimd_last_state, NULL);
 		break;
 	case CPU_PM_EXIT:
 		if (current->mm)
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index bed028364a93..873069056229 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -373,10 +373,6 @@ ENTRY(__boot_cpu_mode)
 	.long	0
 	.popsection
 
-	.align	3
-2:	.quad	.
-	.quad	PAGE_OFFSET
-
 #ifdef CONFIG_SMP
 	.align	3
 1:	.quad	.
diff --git a/arch/arm64/kernel/irq.c b/arch/arm64/kernel/irq.c
index 0f08dfd69ebc..dfa6e3e74fdd 100644
--- a/arch/arm64/kernel/irq.c
+++ b/arch/arm64/kernel/irq.c
@@ -97,19 +97,15 @@ static bool migrate_one_irq(struct irq_desc *desc)
 	if (irqd_is_per_cpu(d) || !cpumask_test_cpu(smp_processor_id(), affinity))
 		return false;
 
-	if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids)
+	if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
+		affinity = cpu_online_mask;
 		ret = true;
+	}
 
-	/*
-	 * when using forced irq_set_affinity we must ensure that the cpu
-	 * being offlined is not present in the affinity mask, it may be
-	 * selected as the target CPU otherwise
-	 */
-	affinity = cpu_online_mask;
 	c = irq_data_get_irq_chip(d);
 	if (!c->irq_set_affinity)
 		pr_debug("IRQ%u: unable to set affinity\n", d->irq);
-	else if (c->irq_set_affinity(d, affinity, true) == IRQ_SET_MASK_OK && ret)
+	else if (c->irq_set_affinity(d, affinity, false) == IRQ_SET_MASK_OK && ret)
 		cpumask_copy(d->affinity, affinity);
 
 	return ret;
diff --git a/arch/arm64/kernel/perf_regs.c b/arch/arm64/kernel/perf_regs.c
index 422ebd63b619..6762ad705587 100644
--- a/arch/arm64/kernel/perf_regs.c
+++ b/arch/arm64/kernel/perf_regs.c
@@ -24,6 +24,12 @@ u64 perf_reg_value(struct pt_regs *regs, int idx)
 			return regs->compat_lr;
 	}
 
+	if ((u32)idx == PERF_REG_ARM64_SP)
+		return regs->sp;
+
+	if ((u32)idx == PERF_REG_ARM64_PC)
+		return regs->pc;
+
 	return regs->regs[idx];
 }
 
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 1309d64aa926..29d48690f2ac 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -230,9 +230,27 @@ void exit_thread(void)
 {
 }
 
+static void tls_thread_flush(void)
+{
+	asm ("msr tpidr_el0, xzr");
+
+	if (is_compat_task()) {
+		current->thread.tp_value = 0;
+
+		/*
+		 * We need to ensure ordering between the shadow state and the
+		 * hardware state, so that we don't corrupt the hardware state
+		 * with a stale shadow state during context switch.
+		 */
+		barrier();
+		asm ("msr tpidrro_el0, xzr");
+	}
+}
+
 void flush_thread(void)
 {
 	fpsimd_flush_thread();
+	tls_thread_flush();
 	flush_ptrace_hw_breakpoint(current);
 }
 
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 70526cfda056..fe63ac5e9bf5 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -87,7 +87,8 @@ static void ptrace_hbptriggered(struct perf_event *bp,
 			break;
 		}
 	}
-	for (i = ARM_MAX_BRP; i < ARM_MAX_HBP_SLOTS && !bp; ++i) {
+
+	for (i = 0; i < ARM_MAX_WRP; ++i) {
 		if (current->thread.debug.hbp_watch[i] == bp) {
 			info.si_errno = -((i << 1) + 1);
 			break;
@@ -662,8 +663,10 @@ static int compat_gpr_get(struct task_struct *target,
 			kbuf += sizeof(reg);
 		} else {
 			ret = copy_to_user(ubuf, &reg, sizeof(reg));
-			if (ret)
+			if (ret) {
+				ret = -EFAULT;
 				break;
+			}
 
 			ubuf += sizeof(reg);
 		}
@@ -701,8 +704,10 @@ static int compat_gpr_set(struct task_struct *target,
 			kbuf += sizeof(reg);
 		} else {
 			ret = copy_from_user(&reg, ubuf, sizeof(reg));
-			if (ret)
-				return ret;
+			if (ret) {
+				ret = -EFAULT;
+				break;
+			}
 
 			ubuf += sizeof(reg);
 		}
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index f6f0ccf35ae6..edb146d01857 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -78,6 +78,7 @@ unsigned int compat_elf_hwcap2 __read_mostly;
 #endif
 
 static const char *cpu_name;
+static const char *machine_name;
 phys_addr_t __fdt_pointer __initdata;
 
 /*
@@ -309,6 +310,8 @@ static void __init setup_machine_fdt(phys_addr_t dt_phys)
 		while (true)
 			cpu_relax();
 	}
+
+	machine_name = of_flat_dt_get_machine_name();
 }
 
 /*
@@ -447,21 +450,10 @@ static int c_show(struct seq_file *m, void *v)
 {
 	int i;
 
-	/*
-	 * Dump out the common processor features in a single line. Userspace
-	 * should read the hwcaps with getauxval(AT_HWCAP) rather than
-	 * attempting to parse this.
-	 */
-	seq_puts(m, "features\t:");
-	for (i = 0; hwcap_str[i]; i++)
-		if (elf_hwcap & (1 << i))
-			seq_printf(m, " %s", hwcap_str[i]);
-	seq_puts(m, "\n\n");
+	seq_printf(m, "Processor\t: %s rev %d (%s)\n",
+		   cpu_name, read_cpuid_id() & 15, ELF_PLATFORM);
 
 	for_each_online_cpu(i) {
-		struct cpuinfo_arm64 *cpuinfo = &per_cpu(cpu_data, i);
-		u32 midr = cpuinfo->reg_midr;
-
 		/*
 		 * glibc reads /proc/cpuinfo to determine the number of
 		 * online processors, looking for lines beginning with
@@ -470,13 +462,25 @@ static int c_show(struct seq_file *m, void *v)
 #ifdef CONFIG_SMP
 		seq_printf(m, "processor\t: %d\n", i);
 #endif
-		seq_printf(m, "implementer\t: 0x%02x\n",
-			   MIDR_IMPLEMENTOR(midr));
-		seq_printf(m, "variant\t\t: 0x%x\n", MIDR_VARIANT(midr));
-		seq_printf(m, "partnum\t\t: 0x%03x\n", MIDR_PARTNUM(midr));
-		seq_printf(m, "revision\t: 0x%x\n\n", MIDR_REVISION(midr));
 	}
 
+	/* dump out the processor features */
+	seq_puts(m, "Features\t: ");
+
+	for (i = 0; hwcap_str[i]; i++)
+		if (elf_hwcap & (1 << i))
+			seq_printf(m, "%s ", hwcap_str[i]);
+
+	seq_printf(m, "\nCPU implementer\t: 0x%02x\n", read_cpuid_id() >> 24);
+	seq_printf(m, "CPU architecture: AArch64\n");
+	seq_printf(m, "CPU variant\t: 0x%x\n", (read_cpuid_id() >> 20) & 15);
+	seq_printf(m, "CPU part\t: 0x%03x\n", (read_cpuid_id() >> 4) & 0xfff);
+	seq_printf(m, "CPU revision\t: %d\n", read_cpuid_id() & 15);
+
+	seq_puts(m, "\n");
+
+	seq_printf(m, "Hardware\t: %s\n", machine_name);
+
 	return 0;
 }
 
diff --git a/arch/arm64/kernel/sys_compat.c b/arch/arm64/kernel/sys_compat.c
index de2b0226e06d..dc47e53e9e28 100644
--- a/arch/arm64/kernel/sys_compat.c
+++ b/arch/arm64/kernel/sys_compat.c
@@ -79,6 +79,12 @@ long compat_arm_syscall(struct pt_regs *regs)
 
 	case __ARM_NR_compat_set_tls:
 		current->thread.tp_value = regs->regs[0];
+
+		/*
+		 * Protect against register corruption from context switch.
+		 * See comment in tls_thread_flush.
+		 */
+		barrier();
 		asm ("msr tpidrro_el0, %0" : : "r" (regs->regs[0]));
 		return 0;