4 files changed, 24 insertions, 11 deletions

diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c
index 8e4431a8821f..65a51331088e 100644
--- a/arch/arm64/kernel/ftrace.c
+++ b/arch/arm64/kernel/ftrace.c
@@ -103,12 +103,16 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 		 * to be revisited if support for multiple ftrace entry points
 		 * is added in the future, but for now, the pr_err() below
 		 * deals with a theoretical issue only.
+		 *
+		 * Note that PLTs are place relative, and plt_entries_equal()
+		 * checks whether they point to the same target. Here, we need
+		 * to check if the actual opcodes are in fact identical,
+		 * regardless of the offset in memory so use memcmp() instead.
 		 */
 		trampoline = get_plt_entry(addr, mod->arch.ftrace_trampoline);
-		if (!plt_entries_equal(mod->arch.ftrace_trampoline,
-				       &trampoline)) {
-			if (!plt_entries_equal(mod->arch.ftrace_trampoline,
-					       &(struct plt_entry){})) {
+		if (memcmp(mod->arch.ftrace_trampoline, &trampoline,
+			   sizeof(trampoline))) {
+			if (plt_entry_is_initialized(mod->arch.ftrace_trampoline)) {
 				pr_err("ftrace: far branches to multiple entry points unsupported inside a single module\n");
 				return -EINVAL;
 			}
diff --git a/arch/arm64/kernel/sdei.c b/arch/arm64/kernel/sdei.c
index 5ba4465e44f0..ea94cf8f9dc6 100644
--- a/arch/arm64/kernel/sdei.c
+++ b/arch/arm64/kernel/sdei.c
@@ -94,6 +94,9 @@ static bool on_sdei_normal_stack(unsigned long sp, struct stack_info *info)
 	unsigned long low = (unsigned long)raw_cpu_read(sdei_stack_normal_ptr);
 	unsigned long high = low + SDEI_STACK_SIZE;
 
+	if (!low)
+		return false;
+
 	if (sp < low || sp >= high)
 		return false;
 
@@ -111,6 +114,9 @@ static bool on_sdei_critical_stack(unsigned long sp, struct stack_info *info)
 	unsigned long low = (unsigned long)raw_cpu_read(sdei_stack_critical_ptr);
 	unsigned long high = low + SDEI_STACK_SIZE;
 
+	if (!low)
+		return false;
+
 	if (sp < low || sp >= high)
 		return false;
 
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index f8482fe5a190..413d566405d1 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -217,7 +217,7 @@ static void __init request_standard_resources(void)
 
 	num_standard_resources = memblock.memory.cnt;
 	res_size = num_standard_resources * sizeof(*standard_resources);
-	standard_resources = memblock_alloc_low(res_size, SMP_CACHE_BYTES);
+	standard_resources = memblock_alloc(res_size, SMP_CACHE_BYTES);
 	if (!standard_resources)
 		panic("%s: Failed to allocate %zu bytes\n", __func__, res_size);
 
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 8ad119c3f665..29755989f616 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -102,10 +102,16 @@ static void dump_instr(const char *lvl, struct pt_regs *regs)
 void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
 {
 	struct stackframe frame;
-	int skip;
+	int skip = 0;
 
 	pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk);
 
+	if (regs) {
+		if (user_mode(regs))
+			return;
+		skip = 1;
+	}
+
 	if (!tsk)
 		tsk = current;
 
@@ -126,7 +132,6 @@ void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
 	frame.graph = 0;
 #endif
 
-	skip = !!regs;
 	printk("Call trace:\n");
 	do {
 		/* skip until specified stack frame */
@@ -176,15 +181,13 @@ static int __die(const char *str, int err, struct pt_regs *regs)
 		return ret;
 
 	print_modules();
-	__show_regs(regs);
 	pr_emerg("Process %.*s (pid: %d, stack limit = 0x%p)\n",
 		 TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk),
 		 end_of_stack(tsk));
+	show_regs(regs);
 
-	if (!user_mode(regs)) {
-		dump_backtrace(regs, tsk);
+	if (!user_mode(regs))
 		dump_instr(KERN_EMERG, regs);
-	}
 
 	return ret;
 }