4 files changed, 33 insertions, 17 deletions

diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h
index 57ef2094af93..630ff08532be 100644
--- a/arch/x86/include/asm/smp.h
+++ b/arch/x86/include/asm/smp.h
@@ -132,7 +132,7 @@ void native_play_dead(void);
 void play_dead_common(void);
 void wbinvd_on_cpu(int cpu);
 int wbinvd_on_all_cpus(void);
-bool wakeup_cpu0(void);
+void cond_wakeup_cpu0(void);
 
 void native_smp_send_reschedule(int cpu);
 void native_send_call_func_ipi(const struct cpumask *mask);
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index f877150a91da..16703c35a944 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1659,13 +1659,17 @@ void play_dead_common(void)
 	local_irq_disable();
 }
 
-bool wakeup_cpu0(void)
+/**
+ * cond_wakeup_cpu0 - Wake up CPU0 if needed.
+ *
+ * If NMI wants to wake up CPU0, start CPU0.
+ */
+void cond_wakeup_cpu0(void)
 {
 	if (smp_processor_id() == 0 && enable_start_cpu0)
-		return true;
-
-	return false;
+		start_cpu0();
 }
+EXPORT_SYMBOL_GPL(cond_wakeup_cpu0);
 
 /*
  * We need to flush the caches before going to sleep, lest we have
@@ -1734,11 +1738,8 @@ static inline void mwait_play_dead(void)
 		__monitor(mwait_ptr, 0, 0);
 		mb();
 		__mwait(eax, 0);
-		/*
-		 * If NMI wants to wake up CPU0, start CPU0.
-		 */
-		if (wakeup_cpu0())
-			start_cpu0();
+
+		cond_wakeup_cpu0();
 	}
 }
 
@@ -1749,11 +1750,8 @@ void hlt_play_dead(void)
 
 	while (1) {
 		native_halt();
-		/*
-		 * If NMI wants to wake up CPU0, start CPU0.
-		 */
-		if (wakeup_cpu0())
-			start_cpu0();
+
+		cond_wakeup_cpu0();
 	}
 }
 
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index b35fc8023884..7f1b3a862e14 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -1689,7 +1689,16 @@ emit_jmp:
 		}
 
 		if (image) {
-			if (unlikely(proglen + ilen > oldproglen)) {
+			/*
+			 * When populating the image, assert that:
+			 *
+			 *  i) We do not write beyond the allocated space, and
+			 * ii) addrs[i] did not change from the prior run, in order
+			 *     to validate assumptions made for computing branch
+			 *     displacements.
+			 */
+			if (unlikely(proglen + ilen > oldproglen ||
+				     proglen + ilen != addrs[i])) {
 				pr_err("bpf_jit: fatal error\n");
 				return -EFAULT;
 			}
diff --git a/arch/x86/net/bpf_jit_comp32.c b/arch/x86/net/bpf_jit_comp32.c
index d17b67c69f89..6a99def7d315 100644
--- a/arch/x86/net/bpf_jit_comp32.c
+++ b/arch/x86/net/bpf_jit_comp32.c
@@ -2276,7 +2276,16 @@ notyet:
 		}
 
 		if (image) {
-			if (unlikely(proglen + ilen > oldproglen)) {
+			/*
+			 * When populating the image, assert that:
+			 *
+			 *  i) We do not write beyond the allocated space, and
+			 * ii) addrs[i] did not change from the prior run, in order
+			 *     to validate assumptions made for computing branch
+			 *     displacements.
+			 */
+			if (unlikely(proglen + ilen > oldproglen ||
+				     proglen + ilen != addrs[i])) {
 				pr_err("bpf_jit: fatal error\n");
 				return -EFAULT;
 			}