5 files changed, 79 insertions, 18 deletions

diff --git a/arch/arm64/include/asm/elf.h b/arch/arm64/include/asm/elf.h
index 3c7037c6ba9b..b618017205a3 100644
--- a/arch/arm64/include/asm/elf.h
+++ b/arch/arm64/include/asm/elf.h
@@ -202,7 +202,7 @@ typedef compat_elf_greg_t		compat_elf_gregset_t[COMPAT_ELF_NGREG];
 ({									\
 	set_thread_flag(TIF_32BIT);					\
  })
-#ifdef CONFIG_GENERIC_COMPAT_VDSO
+#ifdef CONFIG_COMPAT_VDSO
 #define COMPAT_ARCH_DLINFO						\
 do {									\
 	/*								\
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 87a4b2ddc1a1..3f5461f7b560 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -301,7 +301,6 @@ static inline int pte_same(pte_t pte_a, pte_t pte_b)
 /*
  * Huge pte definitions.
  */
-#define pte_huge(pte)		(!(pte_val(pte) & PTE_TABLE_BIT))
 #define pte_mkhuge(pte)		(__pte(pte_val(pte) & ~PTE_TABLE_BIT))
 
 /*
diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h
index fd5b1a4efc70..844e2964b0f5 100644
--- a/arch/arm64/include/asm/processor.h
+++ b/arch/arm64/include/asm/processor.h
@@ -193,6 +193,16 @@ static inline void start_thread_common(struct pt_regs *regs, unsigned long pc)
 		regs->pmr_save = GIC_PRIO_IRQON;
 }
 
+static inline void set_ssbs_bit(struct pt_regs *regs)
+{
+	regs->pstate |= PSR_SSBS_BIT;
+}
+
+static inline void set_compat_ssbs_bit(struct pt_regs *regs)
+{
+	regs->pstate |= PSR_AA32_SSBS_BIT;
+}
+
 static inline void start_thread(struct pt_regs *regs, unsigned long pc,
 				unsigned long sp)
 {
@@ -200,7 +210,7 @@ static inline void start_thread(struct pt_regs *regs, unsigned long pc,
 	regs->pstate = PSR_MODE_EL0t;
 
 	if (arm64_get_ssbd_state() != ARM64_SSBD_FORCE_ENABLE)
-		regs->pstate |= PSR_SSBS_BIT;
+		set_ssbs_bit(regs);
 
 	regs->sp = sp;
 }
@@ -219,7 +229,7 @@ static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc,
 #endif
 
 	if (arm64_get_ssbd_state() != ARM64_SSBD_FORCE_ENABLE)
-		regs->pstate |= PSR_AA32_SSBS_BIT;
+		set_compat_ssbs_bit(regs);
 
 	regs->compat_sp = sp;
 }
diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h
index df45af931459..4d9b1f48dc39 100644
--- a/arch/arm64/include/asm/stacktrace.h
+++ b/arch/arm64/include/asm/stacktrace.h
@@ -8,19 +8,12 @@
 #include <linux/percpu.h>
 #include <linux/sched.h>
 #include <linux/sched/task_stack.h>
+#include <linux/types.h>
 
 #include <asm/memory.h>
 #include <asm/ptrace.h>
 #include <asm/sdei.h>
 
-struct stackframe {
-	unsigned long fp;
-	unsigned long pc;
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-	int graph;
-#endif
-};
-
 enum stack_type {
 	STACK_TYPE_UNKNOWN,
 	STACK_TYPE_TASK,
@@ -28,6 +21,7 @@ enum stack_type {
 	STACK_TYPE_OVERFLOW,
 	STACK_TYPE_SDEI_NORMAL,
 	STACK_TYPE_SDEI_CRITICAL,
+	__NR_STACK_TYPES
 };
 
 struct stack_info {
@@ -36,6 +30,37 @@ struct stack_info {
 	enum stack_type type;
 };
 
+/*
+ * A snapshot of a frame record or fp/lr register values, along with some
+ * accounting information necessary for robust unwinding.
+ *
+ * @fp:          The fp value in the frame record (or the real fp)
+ * @pc:          The fp value in the frame record (or the real lr)
+ *
+ * @stacks_done: Stacks which have been entirely unwound, for which it is no
+ *               longer valid to unwind to.
+ *
+ * @prev_fp:     The fp that pointed to this frame record, or a synthetic value
+ *               of 0. This is used to ensure that within a stack, each
+ *               subsequent frame record is at an increasing address.
+ * @prev_type:   The type of stack this frame record was on, or a synthetic
+ *               value of STACK_TYPE_UNKNOWN. This is used to detect a
+ *               transition from one stack to another.
+ *
+ * @graph:       When FUNCTION_GRAPH_TRACER is selected, holds the index of a
+ *               replacement lr value in the ftrace graph stack.
+ */
+struct stackframe {
+	unsigned long fp;
+	unsigned long pc;
+	DECLARE_BITMAP(stacks_done, __NR_STACK_TYPES);
+	unsigned long prev_fp;
+	enum stack_type prev_type;
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+	int graph;
+#endif
+};
+
 extern int unwind_frame(struct task_struct *tsk, struct stackframe *frame);
 extern void walk_stackframe(struct task_struct *tsk, struct stackframe *frame,
 			    int (*fn)(struct stackframe *, void *), void *data);
@@ -64,8 +89,9 @@ static inline bool on_irq_stack(unsigned long sp,
 	return true;
 }
 
-static inline bool on_task_stack(struct task_struct *tsk, unsigned long sp,
-				struct stack_info *info)
+static inline bool on_task_stack(const struct task_struct *tsk,
+				 unsigned long sp,
+				 struct stack_info *info)
 {
 	unsigned long low = (unsigned long)task_stack_page(tsk);
 	unsigned long high = low + THREAD_SIZE;
@@ -112,10 +138,13 @@ static inline bool on_overflow_stack(unsigned long sp,
  * We can only safely access per-cpu stacks from current in a non-preemptible
  * context.
  */
-static inline bool on_accessible_stack(struct task_struct *tsk,
-					unsigned long sp,
-					struct stack_info *info)
+static inline bool on_accessible_stack(const struct task_struct *tsk,
+				       unsigned long sp,
+				       struct stack_info *info)
 {
+	if (info)
+		info->type = STACK_TYPE_UNKNOWN;
+
 	if (on_task_stack(tsk, sp, info))
 		return true;
 	if (tsk != current || preemptible())
@@ -130,4 +159,27 @@ static inline bool on_accessible_stack(struct task_struct *tsk,
 	return false;
 }
 
+static inline void start_backtrace(struct stackframe *frame,
+				   unsigned long fp, unsigned long pc)
+{
+	frame->fp = fp;
+	frame->pc = pc;
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+	frame->graph = 0;
+#endif
+
+	/*
+	 * Prime the first unwind.
+	 *
+	 * In unwind_frame() we'll check that the FP points to a valid stack,
+	 * which can't be STACK_TYPE_UNKNOWN, and the first unwind will be
+	 * treated as a transition to whichever stack that happens to be. The
+	 * prev_fp value won't be used, but we set it to 0 such that it is
+	 * definitely not an accessible stack address.
+	 */
+	bitmap_zero(frame->stacks_done, __NR_STACK_TYPES);
+	frame->prev_fp = 0;
+	frame->prev_type = STACK_TYPE_UNKNOWN;
+}
+
 #endif	/* __ASM_STACKTRACE_H */
diff --git a/arch/arm64/include/uapi/asm/bpf_perf_event.h b/arch/arm64/include/uapi/asm/bpf_perf_event.h
index b551b741653d..5e1e648aeec4 100644
--- a/arch/arm64/include/uapi/asm/bpf_perf_event.h
+++ b/arch/arm64/include/uapi/asm/bpf_perf_event.h
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: GPL-2.0 */
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
 #ifndef _UAPI__ASM_BPF_PERF_EVENT_H__
 #define _UAPI__ASM_BPF_PERF_EVENT_H__