Merge tag 'loongarch-fixes-6.2-1' of...

Merge tag 'loongarch-fixes-6.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson

Pull LoongArch fixes from Huacai Chen:
 "Fix a missing elf_hwcap, fix some stack unwinder bugs and two trivial
  cleanups"

* tag 'loongarch-fixes-6.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson:
  LoongArch: Add generic ex-handler unwind in prologue unwinder
  LoongArch: Strip guess unwinder out from prologue unwinder
  LoongArch: Use correct sp value to get graph addr in stack unwinders
  LoongArch: Get frame info in unwind_start() when regs is not available
  LoongArch: Adjust PC value when unwind next frame in unwinder
  LoongArch: Simplify larch_insn_gen_xxx implementation
  LoongArch: Use common function sign_extend64()
  LoongArch: Add HWCAP_LOONGARCH_CPUCFG to elf_hwcap

arch/loongarch/include/asm/ftrace.h

@@ -10,8 +10,6 @@
 #define FTRACE_REGS_PLT_IDX	1
 #define NR_FTRACE_PLTS		2
 
-#define GRAPH_FAKE_OFFSET (sizeof(struct pt_regs) - offsetof(struct pt_regs, regs[1]))
-
 #ifdef CONFIG_FUNCTION_TRACER
 
 #define MCOUNT_INSN_SIZE 4		/* sizeof mcount call */

arch/loongarch/include/asm/inst.h

@@ -377,14 +377,6 @@ static inline bool unsigned_imm_check(unsigned long val, unsigned int bit)
 	return val < (1UL << bit);
 }
 
-static inline unsigned long sign_extend(unsigned long val, unsigned int idx)
-{
-	if (!is_imm_negative(val, idx + 1))
-		return ((1UL << idx) - 1) & val;
-	else
-		return ~((1UL << idx) - 1) | val;
-}
-
 #define DEF_EMIT_REG0I26_FORMAT(NAME, OP)				\
 static inline void emit_##NAME(union loongarch_instruction *insn,	\
 			       int offset)				\
@@ -401,6 +393,7 @@ static inline void emit_##NAME(union loongarch_instruction *insn,	\
 }
 
 DEF_EMIT_REG0I26_FORMAT(b, b_op)
+DEF_EMIT_REG0I26_FORMAT(bl, bl_op)
 
 #define DEF_EMIT_REG1I20_FORMAT(NAME, OP)				\
 static inline void emit_##NAME(union loongarch_instruction *insn,	\

arch/loongarch/include/asm/unwind.h

@@ -8,7 +8,9 @@
 #define _ASM_UNWIND_H
 
 #include <linux/sched.h>
+#include <linux/ftrace.h>
 
+#include <asm/ptrace.h>
 #include <asm/stacktrace.h>
 
 enum unwinder_type {
@@ -20,11 +22,13 @@ struct unwind_state {
 	char type; /* UNWINDER_XXX */
 	struct stack_info stack_info;
 	struct task_struct *task;
-	bool first, error, is_ftrace;
+	bool first, error, reset;
 	int graph_idx;
 	unsigned long sp, pc, ra;
 };
 
+bool default_next_frame(struct unwind_state *state);
+
 void unwind_start(struct unwind_state *state,
 		  struct task_struct *task, struct pt_regs *regs);
 bool unwind_next_frame(struct unwind_state *state);
@@ -40,4 +44,39 @@ static inline bool unwind_error(struct unwind_state *state)
 	return state->error;
 }
 
+#define GRAPH_FAKE_OFFSET (sizeof(struct pt_regs) - offsetof(struct pt_regs, regs[1]))
+
+static inline unsigned long unwind_graph_addr(struct unwind_state *state,
+					unsigned long pc, unsigned long cfa)
+{
+	return ftrace_graph_ret_addr(state->task, &state->graph_idx,
+				     pc, (unsigned long *)(cfa - GRAPH_FAKE_OFFSET));
+}
+
+static __always_inline void __unwind_start(struct unwind_state *state,
+					struct task_struct *task, struct pt_regs *regs)
+{
+	memset(state, 0, sizeof(*state));
+	if (regs) {
+		state->sp = regs->regs[3];
+		state->pc = regs->csr_era;
+		state->ra = regs->regs[1];
+	} else if (task && task != current) {
+		state->sp = thread_saved_fp(task);
+		state->pc = thread_saved_ra(task);
+		state->ra = 0;
+	} else {
+		state->sp = (unsigned long)__builtin_frame_address(0);
+		state->pc = (unsigned long)__builtin_return_address(0);
+		state->ra = 0;
+	}
+	state->task = task;
+	get_stack_info(state->sp, state->task, &state->stack_info);
+	state->pc = unwind_graph_addr(state, state->pc, state->sp);
+}
+
+static __always_inline unsigned long __unwind_get_return_address(struct unwind_state *state)
+{
+	return unwind_done(state) ? 0 : state->pc;
+}
 #endif /* _ASM_UNWIND_H */

arch/loongarch/kernel/Makefile

@@ -8,7 +8,7 @@ extra-y		:= vmlinux.lds
 obj-y		+= head.o cpu-probe.o cacheinfo.o env.o setup.o entry.o genex.o \
 		   traps.o irq.o idle.o process.o dma.o mem.o io.o reset.o switch.o \
 		   elf.o syscall.o signal.o time.o topology.o inst.o ptrace.o vdso.o \
-		   alternative.o unaligned.o
+		   alternative.o unaligned.o unwind.o
 
 obj-$(CONFIG_ACPI)		+= acpi.o
 obj-$(CONFIG_EFI) 		+= efi.o

arch/loongarch/kernel/alternative.c

@@ -74,7 +74,7 @@ static void __init_or_module recompute_jump(union loongarch_instruction *buf,
 	switch (src->reg0i26_format.opcode) {
 	case b_op:
 	case bl_op:
-		jump_addr = cur_pc + sign_extend((si_h << 16 | si_l) << 2, 27);
+		jump_addr = cur_pc + sign_extend64((si_h << 16 | si_l) << 2, 27);
 		if (in_alt_jump(jump_addr, start, end))
 			return;
 		offset = jump_addr - pc;
@@ -93,7 +93,7 @@ static void __init_or_module recompute_jump(union loongarch_instruction *buf,
 		fallthrough;
 	case beqz_op:
 	case bnez_op:
-		jump_addr = cur_pc + sign_extend((si_h << 16 | si_l) << 2, 22);
+		jump_addr = cur_pc + sign_extend64((si_h << 16 | si_l) << 2, 22);
 		if (in_alt_jump(jump_addr, start, end))
 			return;
 		offset = jump_addr - pc;
@@ -112,7 +112,7 @@ static void __init_or_module recompute_jump(union loongarch_instruction *buf,
 	case bge_op:
 	case bltu_op:
 	case bgeu_op:
-		jump_addr = cur_pc + sign_extend(si << 2, 17);
+		jump_addr = cur_pc + sign_extend64(si << 2, 17);
 		if (in_alt_jump(jump_addr, start, end))
 			return;
 		offset = jump_addr - pc;

arch/loongarch/kernel/cpu-probe.c

@@ -94,7 +94,7 @@ static void cpu_probe_common(struct cpuinfo_loongarch *c)
 	c->options = LOONGARCH_CPU_CPUCFG | LOONGARCH_CPU_CSR |
 		     LOONGARCH_CPU_TLB | LOONGARCH_CPU_VINT | LOONGARCH_CPU_WATCH;
 
-	elf_hwcap |= HWCAP_LOONGARCH_CRC32;
+	elf_hwcap = HWCAP_LOONGARCH_CPUCFG | HWCAP_LOONGARCH_CRC32;
 
 	config = read_cpucfg(LOONGARCH_CPUCFG1);
 	if (config & CPUCFG1_UAL) {

arch/loongarch/kernel/genex.S

@@ -67,14 +67,17 @@ SYM_FUNC_END(except_vec_cex)
 	.macro	BUILD_HANDLER exception handler prep
 	.align	5
 	SYM_FUNC_START(handle_\exception)
+	666:
 	BACKUP_T0T1
 	SAVE_ALL
 	build_prep_\prep
 	move	a0, sp
 	la.abs	t0, do_\handler
 	jirl	ra, t0, 0
+	668:
 	RESTORE_ALL_AND_RET
 	SYM_FUNC_END(handle_\exception)
+	SYM_DATA(unwind_hint_\exception, .word 668b - 666b)
 	.endm
 
 	BUILD_HANDLER ade ade badv

arch/loongarch/kernel/inst.c

@@ -58,7 +58,6 @@ u32 larch_insn_gen_nop(void)
 u32 larch_insn_gen_b(unsigned long pc, unsigned long dest)
 {
 	long offset = dest - pc;
-	unsigned int immediate_l, immediate_h;
 	union loongarch_instruction insn;
 
 	if ((offset & 3) || offset < -SZ_128M || offset >= SZ_128M) {
@@ -66,15 +65,7 @@ u32 larch_insn_gen_b(unsigned long pc, unsigned long dest)
 		return INSN_BREAK;
 	}
 
-	offset >>= 2;
-
-	immediate_l = offset & 0xffff;
-	offset >>= 16;
-	immediate_h = offset & 0x3ff;
-
-	insn.reg0i26_format.opcode = b_op;
-	insn.reg0i26_format.immediate_l = immediate_l;
-	insn.reg0i26_format.immediate_h = immediate_h;
+	emit_b(&insn, offset >> 2);
 
 	return insn.word;
 }
@@ -82,7 +73,6 @@ u32 larch_insn_gen_b(unsigned long pc, unsigned long dest)
 u32 larch_insn_gen_bl(unsigned long pc, unsigned long dest)
 {
 	long offset = dest - pc;
-	unsigned int immediate_l, immediate_h;
 	union loongarch_instruction insn;
 
 	if ((offset & 3) || offset < -SZ_128M || offset >= SZ_128M) {
@@ -90,15 +80,7 @@ u32 larch_insn_gen_bl(unsigned long pc, unsigned long dest)
 		return INSN_BREAK;
 	}
 
-	offset >>= 2;
-
-	immediate_l = offset & 0xffff;
-	offset >>= 16;
-	immediate_h = offset & 0x3ff;
-
-	insn.reg0i26_format.opcode = bl_op;
-	insn.reg0i26_format.immediate_l = immediate_l;
-	insn.reg0i26_format.immediate_h = immediate_h;
+	emit_bl(&insn, offset >> 2);
 
 	return insn.word;
 }
@@ -107,10 +89,7 @@ u32 larch_insn_gen_or(enum loongarch_gpr rd, enum loongarch_gpr rj, enum loongar
 {
 	union loongarch_instruction insn;
 
-	insn.reg3_format.opcode = or_op;
-	insn.reg3_format.rd = rd;
-	insn.reg3_format.rj = rj;
-	insn.reg3_format.rk = rk;
+	emit_or(&insn, rd, rj, rk);
 
 	return insn.word;
 }
@@ -124,9 +103,7 @@ u32 larch_insn_gen_lu12iw(enum loongarch_gpr rd, int imm)
 {
 	union loongarch_instruction insn;
 
-	insn.reg1i20_format.opcode = lu12iw_op;
-	insn.reg1i20_format.rd = rd;
-	insn.reg1i20_format.immediate = imm;
+	emit_lu12iw(&insn, rd, imm);
 
 	return insn.word;
 }
@@ -135,9 +112,7 @@ u32 larch_insn_gen_lu32id(enum loongarch_gpr rd, int imm)
 {
 	union loongarch_instruction insn;
 
-	insn.reg1i20_format.opcode = lu32id_op;
-	insn.reg1i20_format.rd = rd;
-	insn.reg1i20_format.immediate = imm;
+	emit_lu32id(&insn, rd, imm);
 
 	return insn.word;
 }
@@ -146,10 +121,7 @@ u32 larch_insn_gen_lu52id(enum loongarch_gpr rd, enum loongarch_gpr rj, int imm)
 {
 	union loongarch_instruction insn;
 
-	insn.reg2i12_format.opcode = lu52id_op;
-	insn.reg2i12_format.rd = rd;
-	insn.reg2i12_format.rj = rj;
-	insn.reg2i12_format.immediate = imm;
+	emit_lu52id(&insn, rd, rj, imm);
 
 	return insn.word;
 }
@@ -158,10 +130,7 @@ u32 larch_insn_gen_jirl(enum loongarch_gpr rd, enum loongarch_gpr rj, unsigned l
 {
 	union loongarch_instruction insn;
 
-	insn.reg2i16_format.opcode = jirl_op;
-	insn.reg2i16_format.rd = rd;
-	insn.reg2i16_format.rj = rj;
-	insn.reg2i16_format.immediate = (dest - pc) >> 2;
+	emit_jirl(&insn, rj, rd, (dest - pc) >> 2);
 
 	return insn.word;
 }

arch/loongarch/kernel/process.c

@@ -191,20 +191,14 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 
 unsigned long __get_wchan(struct task_struct *task)
 {
-	unsigned long pc;
+	unsigned long pc = 0;
 	struct unwind_state state;
 
 	if (!try_get_task_stack(task))
 		return 0;
 
-	unwind_start(&state, task, NULL);
-	state.sp = thread_saved_fp(task);
-	get_stack_info(state.sp, state.task, &state.stack_info);
-	state.pc = thread_saved_ra(task);
-#ifdef CONFIG_UNWINDER_PROLOGUE
-	state.type = UNWINDER_PROLOGUE;
-#endif
-	for (; !unwind_done(&state); unwind_next_frame(&state)) {
+	for (unwind_start(&state, task, NULL);
+	     !unwind_done(&state); unwind_next_frame(&state)) {
 		pc = unwind_get_return_address(&state);
 		if (!pc)
 			break;

arch/loongarch/kernel/traps.c

@@ -72,9 +72,6 @@ static void show_backtrace(struct task_struct *task, const struct pt_regs *regs,
 	if (!task)
 		task = current;
 
-	if (user_mode(regs))
-		state.type = UNWINDER_GUESS;
-
 	printk("%sCall Trace:", loglvl);
 	for (unwind_start(&state, task, pregs);
 	      !unwind_done(&state); unwind_next_frame(&state)) {

arch/loongarch/kernel/unwind.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2022-2023 Loongson Technology Corporation Limited
+ */
+#include <linux/kernel.h>
+#include <linux/ftrace.h>
+
+#include <asm/unwind.h>
+
+bool default_next_frame(struct unwind_state *state)
+{
+	struct stack_info *info = &state->stack_info;
+	unsigned long addr;
+
+	if (unwind_done(state))
+		return false;
+
+	do {
+		for (state->sp += sizeof(unsigned long);
+		     state->sp < info->end; state->sp += sizeof(unsigned long)) {
+			addr = *(unsigned long *)(state->sp);
+			state->pc = unwind_graph_addr(state, addr, state->sp + 8);
+			if (__kernel_text_address(state->pc))
+				return true;
+		}
+
+		state->sp = info->next_sp;
+
+	} while (!get_stack_info(state->sp, state->task, info));
+
+	return false;
+}

arch/loongarch/kernel/unwind_guess.c

@@ -2,37 +2,18 @@
 /*
  * Copyright (C) 2022 Loongson Technology Corporation Limited
  */
-#include <linux/kernel.h>
-#include <linux/ftrace.h>
-
 #include <asm/unwind.h>
 
 unsigned long unwind_get_return_address(struct unwind_state *state)
 {
-	if (unwind_done(state))
-		return 0;
-	else if (state->first)
-		return state->pc;
-
-	return *(unsigned long *)(state->sp);
+	return __unwind_get_return_address(state);
 }
 EXPORT_SYMBOL_GPL(unwind_get_return_address);
 
 void unwind_start(struct unwind_state *state, struct task_struct *task,
 		    struct pt_regs *regs)
 {
-	memset(state, 0, sizeof(*state));
-
-	if (regs) {
-		state->sp = regs->regs[3];
-		state->pc = regs->csr_era;
-	}
-
-	state->task = task;
-	state->first = true;
-
-	get_stack_info(state->sp, state->task, &state->stack_info);
-
+	__unwind_start(state, task, regs);
 	if (!unwind_done(state) && !__kernel_text_address(state->pc))
 		unwind_next_frame(state);
 }
@@ -40,30 +21,6 @@ EXPORT_SYMBOL_GPL(unwind_start);
 
 bool unwind_next_frame(struct unwind_state *state)
 {
-	struct stack_info *info = &state->stack_info;
-	unsigned long addr;
-
-	if (unwind_done(state))
-		return false;
-
-	if (state->first)
-		state->first = false;
-
-	do {
-		for (state->sp += sizeof(unsigned long);
-		     state->sp < info->end;
-		     state->sp += sizeof(unsigned long)) {
-			addr = *(unsigned long *)(state->sp);
-			state->pc = ftrace_graph_ret_addr(state->task, &state->graph_idx,
-					addr, (unsigned long *)(state->sp - GRAPH_FAKE_OFFSET));
-			if (__kernel_text_address(addr))
-				return true;
-		}
-
-		state->sp = info->next_sp;
-
-	} while (!get_stack_info(state->sp, state->task, info));
-
-	return false;
+	return default_next_frame(state);
 }
 EXPORT_SYMBOL_GPL(unwind_next_frame);

arch/loongarch/kernel/unwind_prologue.c

@@ -2,61 +2,116 @@
 /*
  * Copyright (C) 2022 Loongson Technology Corporation Limited
  */
+#include <linux/cpumask.h>
 #include <linux/ftrace.h>
 #include <linux/kallsyms.h>
 
 #include <asm/inst.h>
+#include <asm/loongson.h>
 #include <asm/ptrace.h>
+#include <asm/setup.h>
 #include <asm/unwind.h>
 
-static inline void unwind_state_fixup(struct unwind_state *state)
-{
-#ifdef CONFIG_DYNAMIC_FTRACE
-	static unsigned long ftrace = (unsigned long)ftrace_call + 4;
-
-	if (state->pc == ftrace)
-		state->is_ftrace = true;
+extern const int unwind_hint_ade;
+extern const int unwind_hint_ale;
+extern const int unwind_hint_bp;
+extern const int unwind_hint_fpe;
+extern const int unwind_hint_fpu;
+extern const int unwind_hint_lsx;
+extern const int unwind_hint_lasx;
+extern const int unwind_hint_lbt;
+extern const int unwind_hint_ri;
+extern const int unwind_hint_watch;
+extern unsigned long eentry;
+#ifdef CONFIG_NUMA
+extern unsigned long pcpu_handlers[NR_CPUS];
 #endif
-}
 
-unsigned long unwind_get_return_address(struct unwind_state *state)
+static inline bool scan_handlers(unsigned long entry_offset)
 {
+	int idx, offset;
 
-	if (unwind_done(state))
-		return 0;
-	else if (state->type)
-		return state->pc;
-	else if (state->first)
-		return state->pc;
-
-	return *(unsigned long *)(state->sp);
+	if (entry_offset >= EXCCODE_INT_START * VECSIZE)
+		return false;
 
+	idx = entry_offset / VECSIZE;
+	offset = entry_offset % VECSIZE;
+	switch (idx) {
+	case EXCCODE_ADE:
+		return offset == unwind_hint_ade;
+	case EXCCODE_ALE:
+		return offset == unwind_hint_ale;
+	case EXCCODE_BP:
+		return offset == unwind_hint_bp;
+	case EXCCODE_FPE:
+		return offset == unwind_hint_fpe;
+	case EXCCODE_FPDIS:
+		return offset == unwind_hint_fpu;
+	case EXCCODE_LSXDIS:
+		return offset == unwind_hint_lsx;
+	case EXCCODE_LASXDIS:
+		return offset == unwind_hint_lasx;
+	case EXCCODE_BTDIS:
+		return offset == unwind_hint_lbt;
+	case EXCCODE_INE:
+		return offset == unwind_hint_ri;
+	case EXCCODE_WATCH:
+		return offset == unwind_hint_watch;
+	default:
+		return false;
+	}
 }
-EXPORT_SYMBOL_GPL(unwind_get_return_address);
 
-static bool unwind_by_guess(struct unwind_state *state)
+static inline bool fix_exception(unsigned long pc)
 {
-	struct stack_info *info = &state->stack_info;
-	unsigned long addr;
-
-	for (state->sp += sizeof(unsigned long);
-	     state->sp < info->end;
-	     state->sp += sizeof(unsigned long)) {
-		addr = *(unsigned long *)(state->sp);
-		state->pc = ftrace_graph_ret_addr(state->task, &state->graph_idx,
-				addr, (unsigned long *)(state->sp - GRAPH_FAKE_OFFSET));
-		if (__kernel_text_address(addr))
+#ifdef CONFIG_NUMA
+	int cpu;
+
+	for_each_possible_cpu(cpu) {
+		if (!pcpu_handlers[cpu])
+			continue;
+		if (scan_handlers(pc - pcpu_handlers[cpu]))
 			return true;
 	}
+#endif
+	return scan_handlers(pc - eentry);
+}
 
+/*
+ * As we meet ftrace_regs_entry, reset first flag like first doing
+ * tracing. Prologue analysis will stop soon because PC is at entry.
+ */
+static inline bool fix_ftrace(unsigned long pc)
+{
+#ifdef CONFIG_DYNAMIC_FTRACE
+	return pc == (unsigned long)ftrace_call + LOONGARCH_INSN_SIZE;
+#else
 	return false;
+#endif
 }
 
+static inline bool unwind_state_fixup(struct unwind_state *state)
+{
+	if (!fix_exception(state->pc) && !fix_ftrace(state->pc))
+		return false;
+
+	state->reset = true;
+	return true;
+}
+
+/*
+ * LoongArch function prologue is like follows,
+ *     [instructions not use stack var]
+ *     addi.d sp, sp, -imm
+ *     st.d   xx, sp, offset <- save callee saved regs and
+ *     st.d   yy, sp, offset    save ra if function is nest.
+ *     [others instructions]
+ */
 static bool unwind_by_prologue(struct unwind_state *state)
 {
 	long frame_ra = -1;
 	unsigned long frame_size = 0;
-	unsigned long size, offset, pc = state->pc;
+	unsigned long size, offset, pc;
 	struct pt_regs *regs;
 	struct stack_info *info = &state->stack_info;
 	union loongarch_instruction *ip, *ip_end;
@@ -64,20 +119,21 @@ static bool unwind_by_prologue(struct unwind_state *state)
 	if (state->sp >= info->end || state->sp < info->begin)
 		return false;
 
-	if (state->is_ftrace) {
-		/*
-		 * As we meet ftrace_regs_entry, reset first flag like first doing
-		 * tracing. Prologue analysis will stop soon because PC is at entry.
-		 */
+	if (state->reset) {
 		regs = (struct pt_regs *)state->sp;
 		state->first = true;
-		state->is_ftrace = false;
+		state->reset = false;
 		state->pc = regs->csr_era;
 		state->ra = regs->regs[1];
 		state->sp = regs->regs[3];
 		return true;
 	}
 
+	/*
+	 * When first is not set, the PC is a return address in the previous frame.
+	 * We need to adjust its value in case overflow to the next symbol.
+	 */
+	pc = state->pc - (state->first ? 0 : LOONGARCH_INSN_SIZE);
 	if (!kallsyms_lookup_size_offset(pc, &size, &offset))
 		return false;
 
@@ -93,6 +149,10 @@ static bool unwind_by_prologue(struct unwind_state *state)
 		ip++;
 	}
 
+	/*
+	 * Can't find stack alloc action, PC may be in a leaf function. Only the
+	 * first being true is reasonable, otherwise indicate analysis is broken.
+	 */
 	if (!frame_size) {
 		if (state->first)
 			goto first;
@@ -110,6 +170,7 @@ static bool unwind_by_prologue(struct unwind_state *state)
 		ip++;
 	}
 
+	/* Can't find save $ra action, PC may be in a leaf function, too. */
 	if (frame_ra < 0) {
 		if (state->first) {
 			state->sp = state->sp + frame_size;
@@ -118,88 +179,47 @@ static bool unwind_by_prologue(struct unwind_state *state)
 		return false;
 	}
 
-	if (state->first)
-		state->first = false;
-
 	state->pc = *(unsigned long *)(state->sp + frame_ra);
 	state->sp = state->sp + frame_size;
 	goto out;
 
 first:
-	state->first = false;
-	if (state->pc == state->ra)
-		return false;
-
 	state->pc = state->ra;
 
 out:
-	unwind_state_fixup(state);
-	return !!__kernel_text_address(state->pc);
-}
-
-void unwind_start(struct unwind_state *state, struct task_struct *task,
-		    struct pt_regs *regs)
-{
-	memset(state, 0, sizeof(*state));
-
-	if (regs &&  __kernel_text_address(regs->csr_era)) {
-		state->pc = regs->csr_era;
-		state->sp = regs->regs[3];
-		state->ra = regs->regs[1];
-		state->type = UNWINDER_PROLOGUE;
-	}
-
-	state->task = task;
-	state->first = true;
-
-	get_stack_info(state->sp, state->task, &state->stack_info);
-
-	if (!unwind_done(state) && !__kernel_text_address(state->pc))
-		unwind_next_frame(state);
+	state->first = false;
+	return unwind_state_fixup(state) || __kernel_text_address(state->pc);
 }
-EXPORT_SYMBOL_GPL(unwind_start);
 
-bool unwind_next_frame(struct unwind_state *state)
+static bool next_frame(struct unwind_state *state)
 {
-	struct stack_info *info = &state->stack_info;
-	struct pt_regs *regs;
 	unsigned long pc;
+	struct pt_regs *regs;
+	struct stack_info *info = &state->stack_info;
 
 	if (unwind_done(state))
 		return false;
 
 	do {
-		switch (state->type) {
-		case UNWINDER_GUESS:
-			state->first = false;
-			if (unwind_by_guess(state))
-				return true;
-			break;
+		if (unwind_by_prologue(state)) {
+			state->pc = unwind_graph_addr(state, state->pc, state->sp);
+			return true;
+		}
+
+		if (info->type == STACK_TYPE_IRQ && info->end == state->sp) {
+			regs = (struct pt_regs *)info->next_sp;
+			pc = regs->csr_era;
+
+			if (user_mode(regs) || !__kernel_text_address(pc))
+				return false;
+
+			state->first = true;
+			state->pc = pc;
+			state->ra = regs->regs[1];
+			state->sp = regs->regs[3];
+			get_stack_info(state->sp, state->task, info);
 
-		case UNWINDER_PROLOGUE:
-			if (unwind_by_prologue(state)) {
-				state->pc = ftrace_graph_ret_addr(state->task, &state->graph_idx,
-						state->pc, (unsigned long *)(state->sp - GRAPH_FAKE_OFFSET));
-				return true;
-			}
-
-			if (info->type == STACK_TYPE_IRQ &&
-				info->end == state->sp) {
-				regs = (struct pt_regs *)info->next_sp;
-				pc = regs->csr_era;
-
-				if (user_mode(regs) || !__kernel_text_address(pc))
-					return false;
-
-				state->first = true;
-				state->ra = regs->regs[1];
-				state->sp = regs->regs[3];
-				state->pc = ftrace_graph_ret_addr(state->task, &state->graph_idx,
-						pc, (unsigned long *)(state->sp - GRAPH_FAKE_OFFSET));
-				get_stack_info(state->sp, state->task, info);
-
-				return true;
-			}
+			return true;
 		}
 
 		state->sp = info->next_sp;
@@ -208,4 +228,36 @@ bool unwind_next_frame(struct unwind_state *state)
 
 	return false;
 }
+
+unsigned long unwind_get_return_address(struct unwind_state *state)
+{
+	return __unwind_get_return_address(state);
+}
+EXPORT_SYMBOL_GPL(unwind_get_return_address);
+
+void unwind_start(struct unwind_state *state, struct task_struct *task,
+		    struct pt_regs *regs)
+{
+	__unwind_start(state, task, regs);
+	state->type = UNWINDER_PROLOGUE;
+	state->first = true;
+
+	/*
+	 * The current PC is not kernel text address, we cannot find its
+	 * relative symbol. Thus, prologue analysis will be broken. Luckily,
+	 * we can use the default_next_frame().
+	 */
+	if (!__kernel_text_address(state->pc)) {
+		state->type = UNWINDER_GUESS;
+		if (!unwind_done(state))
+			unwind_next_frame(state);
+	}
+}
+EXPORT_SYMBOL_GPL(unwind_start);
+
+bool unwind_next_frame(struct unwind_state *state)
+{
+	return state->type == UNWINDER_PROLOGUE ?
+			next_frame(state) : default_next_frame(state);
+}
 EXPORT_SYMBOL_GPL(unwind_next_frame);

arch/loongarch/mm/tlb.c

@@ -251,7 +251,7 @@ static void output_pgtable_bits_defines(void)
 }
 
 #ifdef CONFIG_NUMA
-static unsigned long pcpu_handlers[NR_CPUS];
+unsigned long pcpu_handlers[NR_CPUS];
 #endif
 extern long exception_handlers[VECSIZE * 128 / sizeof(long)];