Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 435 insertions, 0 deletions

diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
new file mode 100644
index 0000000000..67d0073fb6
--- /dev/null
+++ b/arch/riscv/kernel/traps.c
@@ -0,0 +1,435 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2012 Regents of the University of California
+ */
+
+#include <linux/cpu.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
+#include <linux/sched/signal.h>
+#include <linux/signal.h>
+#include <linux/kdebug.h>
+#include <linux/uaccess.h>
+#include <linux/kprobes.h>
+#include <linux/uprobes.h>
+#include <asm/uprobes.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/irq.h>
+#include <linux/kexec.h>
+#include <linux/entry-common.h>
+
+#include <asm/asm-prototypes.h>
+#include <asm/bug.h>
+#include <asm/cfi.h>
+#include <asm/csr.h>
+#include <asm/processor.h>
+#include <asm/ptrace.h>
+#include <asm/syscall.h>
+#include <asm/thread_info.h>
+#include <asm/vector.h>
+#include <asm/irq_stack.h>
+
+int show_unhandled_signals = 1;
+
+static DEFINE_SPINLOCK(die_lock);
+
+static void dump_kernel_instr(const char *loglvl, struct pt_regs *regs)
+{
+	char str[sizeof("0000 ") * 12 + 2 + 1], *p = str;
+	const u16 *insns = (u16 *)instruction_pointer(regs);
+	long bad;
+	u16 val;
+	int i;
+
+	for (i = -10; i < 2; i++) {
+		bad = get_kernel_nofault(val, &insns[i]);
+		if (!bad) {
+			p += sprintf(p, i == 0 ? "(%04hx) " : "%04hx ", val);
+		} else {
+			printk("%sCode: Unable to access instruction at 0x%px.\n",
+			       loglvl, &insns[i]);
+			return;
+		}
+	}
+	printk("%sCode: %s\n", loglvl, str);
+}
+
+void die(struct pt_regs *regs, const char *str)
+{
+	static int die_counter;
+	int ret;
+	long cause;
+	unsigned long flags;
+
+	oops_enter();
+
+	spin_lock_irqsave(&die_lock, flags);
+	console_verbose();
+	bust_spinlocks(1);
+
+	pr_emerg("%s [#%d]\n", str, ++die_counter);
+	print_modules();
+	if (regs) {
+		show_regs(regs);
+		dump_kernel_instr(KERN_EMERG, regs);
+	}
+
+	cause = regs ? regs->cause : -1;
+	ret = notify_die(DIE_OOPS, str, regs, 0, cause, SIGSEGV);
+
+	if (kexec_should_crash(current))
+		crash_kexec(regs);
+
+	bust_spinlocks(0);
+	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
+	spin_unlock_irqrestore(&die_lock, flags);
+	oops_exit();
+
+	if (in_interrupt())
+		panic("Fatal exception in interrupt");
+	if (panic_on_oops)
+		panic("Fatal exception");
+	if (ret != NOTIFY_STOP)
+		make_task_dead(SIGSEGV);
+}
+
+void do_trap(struct pt_regs *regs, int signo, int code, unsigned long addr)
+{
+	struct task_struct *tsk = current;
+
+	if (show_unhandled_signals && unhandled_signal(tsk, signo)
+	    && printk_ratelimit()) {
+		pr_info("%s[%d]: unhandled signal %d code 0x%x at 0x" REG_FMT,
+			tsk->comm, task_pid_nr(tsk), signo, code, addr);
+		print_vma_addr(KERN_CONT " in ", instruction_pointer(regs));
+		pr_cont("\n");
+		__show_regs(regs);
+	}
+
+	force_sig_fault(signo, code, (void __user *)addr);
+}
+
+static void do_trap_error(struct pt_regs *regs, int signo, int code,
+	unsigned long addr, const char *str)
+{
+	current->thread.bad_cause = regs->cause;
+
+	if (user_mode(regs)) {
+		do_trap(regs, signo, code, addr);
+	} else {
+		if (!fixup_exception(regs))
+			die(regs, str);
+	}
+}
+
+#if defined(CONFIG_XIP_KERNEL) && defined(CONFIG_RISCV_ALTERNATIVE)
+#define __trap_section __noinstr_section(".xip.traps")
+#else
+#define __trap_section noinstr
+#endif
+#define DO_ERROR_INFO(name, signo, code, str)					\
+asmlinkage __visible __trap_section void name(struct pt_regs *regs)		\
+{										\
+	if (user_mode(regs)) {							\
+		irqentry_enter_from_user_mode(regs);				\
+		do_trap_error(regs, signo, code, regs->epc, "Oops - " str);	\
+		irqentry_exit_to_user_mode(regs);				\
+	} else {								\
+		irqentry_state_t state = irqentry_nmi_enter(regs);		\
+		do_trap_error(regs, signo, code, regs->epc, "Oops - " str);	\
+		irqentry_nmi_exit(regs, state);					\
+	}									\
+}
+
+DO_ERROR_INFO(do_trap_unknown,
+	SIGILL, ILL_ILLTRP, "unknown exception");
+DO_ERROR_INFO(do_trap_insn_misaligned,
+	SIGBUS, BUS_ADRALN, "instruction address misaligned");
+DO_ERROR_INFO(do_trap_insn_fault,
+	SIGSEGV, SEGV_ACCERR, "instruction access fault");
+
+asmlinkage __visible __trap_section void do_trap_insn_illegal(struct pt_regs *regs)
+{
+	bool handled;
+
+	if (user_mode(regs)) {
+		irqentry_enter_from_user_mode(regs);
+
+		local_irq_enable();
+
+		handled = riscv_v_first_use_handler(regs);
+
+		local_irq_disable();
+
+		if (!handled)
+			do_trap_error(regs, SIGILL, ILL_ILLOPC, regs->epc,
+				      "Oops - illegal instruction");
+
+		irqentry_exit_to_user_mode(regs);
+	} else {
+		irqentry_state_t state = irqentry_nmi_enter(regs);
+
+		do_trap_error(regs, SIGILL, ILL_ILLOPC, regs->epc,
+			      "Oops - illegal instruction");
+
+		irqentry_nmi_exit(regs, state);
+	}
+}
+
+DO_ERROR_INFO(do_trap_load_fault,
+	SIGSEGV, SEGV_ACCERR, "load access fault");
+#ifndef CONFIG_RISCV_M_MODE
+DO_ERROR_INFO(do_trap_load_misaligned,
+	SIGBUS, BUS_ADRALN, "Oops - load address misaligned");
+DO_ERROR_INFO(do_trap_store_misaligned,
+	SIGBUS, BUS_ADRALN, "Oops - store (or AMO) address misaligned");
+#else
+int handle_misaligned_load(struct pt_regs *regs);
+int handle_misaligned_store(struct pt_regs *regs);
+
+asmlinkage __visible __trap_section void do_trap_load_misaligned(struct pt_regs *regs)
+{
+	if (user_mode(regs)) {
+		irqentry_enter_from_user_mode(regs);
+
+		if (handle_misaligned_load(regs))
+			do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
+			      "Oops - load address misaligned");
+
+		irqentry_exit_to_user_mode(regs);
+	} else {
+		irqentry_state_t state = irqentry_nmi_enter(regs);
+
+		if (handle_misaligned_load(regs))
+			do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
+			      "Oops - load address misaligned");
+
+		irqentry_nmi_exit(regs, state);
+	}
+}
+
+asmlinkage __visible __trap_section void do_trap_store_misaligned(struct pt_regs *regs)
+{
+	if (user_mode(regs)) {
+		irqentry_enter_from_user_mode(regs);
+
+		if (handle_misaligned_store(regs))
+			do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
+				"Oops - store (or AMO) address misaligned");
+
+		irqentry_exit_to_user_mode(regs);
+	} else {
+		irqentry_state_t state = irqentry_nmi_enter(regs);
+
+		if (handle_misaligned_store(regs))
+			do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
+				"Oops - store (or AMO) address misaligned");
+
+		irqentry_nmi_exit(regs, state);
+	}
+}
+#endif
+DO_ERROR_INFO(do_trap_store_fault,
+	SIGSEGV, SEGV_ACCERR, "store (or AMO) access fault");
+DO_ERROR_INFO(do_trap_ecall_s,
+	SIGILL, ILL_ILLTRP, "environment call from S-mode");
+DO_ERROR_INFO(do_trap_ecall_m,
+	SIGILL, ILL_ILLTRP, "environment call from M-mode");
+
+static inline unsigned long get_break_insn_length(unsigned long pc)
+{
+	bug_insn_t insn;
+
+	if (get_kernel_nofault(insn, (bug_insn_t *)pc))
+		return 0;
+
+	return GET_INSN_LENGTH(insn);
+}
+
+static bool probe_single_step_handler(struct pt_regs *regs)
+{
+	bool user = user_mode(regs);
+
+	return user ? uprobe_single_step_handler(regs) : kprobe_single_step_handler(regs);
+}
+
+static bool probe_breakpoint_handler(struct pt_regs *regs)
+{
+	bool user = user_mode(regs);
+
+	return user ? uprobe_breakpoint_handler(regs) : kprobe_breakpoint_handler(regs);
+}
+
+void handle_break(struct pt_regs *regs)
+{
+	if (probe_single_step_handler(regs))
+		return;
+
+	if (probe_breakpoint_handler(regs))
+		return;
+
+	current->thread.bad_cause = regs->cause;
+
+	if (user_mode(regs))
+		force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->epc);
+#ifdef CONFIG_KGDB
+	else if (notify_die(DIE_TRAP, "EBREAK", regs, 0, regs->cause, SIGTRAP)
+								== NOTIFY_STOP)
+		return;
+#endif
+	else if (report_bug(regs->epc, regs) == BUG_TRAP_TYPE_WARN ||
+		 handle_cfi_failure(regs) == BUG_TRAP_TYPE_WARN)
+		regs->epc += get_break_insn_length(regs->epc);
+	else
+		die(regs, "Kernel BUG");
+}
+
+asmlinkage __visible __trap_section void do_trap_break(struct pt_regs *regs)
+{
+	if (user_mode(regs)) {
+		irqentry_enter_from_user_mode(regs);
+
+		handle_break(regs);
+
+		irqentry_exit_to_user_mode(regs);
+	} else {
+		irqentry_state_t state = irqentry_nmi_enter(regs);
+
+		handle_break(regs);
+
+		irqentry_nmi_exit(regs, state);
+	}
+}
+
+asmlinkage __visible __trap_section void do_trap_ecall_u(struct pt_regs *regs)
+{
+	if (user_mode(regs)) {
+		long syscall = regs->a7;
+
+		regs->epc += 4;
+		regs->orig_a0 = regs->a0;
+
+		riscv_v_vstate_discard(regs);
+
+		syscall = syscall_enter_from_user_mode(regs, syscall);
+
+		if (syscall >= 0 && syscall < NR_syscalls)
+			syscall_handler(regs, syscall);
+		else if (syscall != -1)
+			regs->a0 = -ENOSYS;
+
+		syscall_exit_to_user_mode(regs);
+	} else {
+		irqentry_state_t state = irqentry_nmi_enter(regs);
+
+		do_trap_error(regs, SIGILL, ILL_ILLTRP, regs->epc,
+			"Oops - environment call from U-mode");
+
+		irqentry_nmi_exit(regs, state);
+	}
+
+}
+
+#ifdef CONFIG_MMU
+asmlinkage __visible noinstr void do_page_fault(struct pt_regs *regs)
+{
+	irqentry_state_t state = irqentry_enter(regs);
+
+	handle_page_fault(regs);
+
+	local_irq_disable();
+
+	irqentry_exit(regs, state);
+}
+#endif
+
+static void noinstr handle_riscv_irq(struct pt_regs *regs)
+{
+	struct pt_regs *old_regs;
+
+	irq_enter_rcu();
+	old_regs = set_irq_regs(regs);
+	handle_arch_irq(regs);
+	set_irq_regs(old_regs);
+	irq_exit_rcu();
+}
+
+asmlinkage void noinstr do_irq(struct pt_regs *regs)
+{
+	irqentry_state_t state = irqentry_enter(regs);
+#ifdef CONFIG_IRQ_STACKS
+	if (on_thread_stack()) {
+		ulong *sp = per_cpu(irq_stack_ptr, smp_processor_id())
+					+ IRQ_STACK_SIZE/sizeof(ulong);
+		__asm__ __volatile(
+		"addi	sp, sp, -"RISCV_SZPTR  "\n"
+		REG_S"  ra, (sp)		\n"
+		"addi	sp, sp, -"RISCV_SZPTR  "\n"
+		REG_S"  s0, (sp)		\n"
+		"addi	s0, sp, 2*"RISCV_SZPTR "\n"
+		"move	sp, %[sp]		\n"
+		"move	a0, %[regs]		\n"
+		"call	handle_riscv_irq	\n"
+		"addi	sp, s0, -2*"RISCV_SZPTR"\n"
+		REG_L"  s0, (sp)		\n"
+		"addi	sp, sp, "RISCV_SZPTR   "\n"
+		REG_L"  ra, (sp)		\n"
+		"addi	sp, sp, "RISCV_SZPTR   "\n"
+		:
+		: [sp] "r" (sp), [regs] "r" (regs)
+		: "a0", "a1", "a2", "a3", "a4", "a5", "a6", "a7",
+		  "t0", "t1", "t2", "t3", "t4", "t5", "t6",
+#ifndef CONFIG_FRAME_POINTER
+		  "s0",
+#endif
+		  "memory");
+	} else
+#endif
+		handle_riscv_irq(regs);
+
+	irqentry_exit(regs, state);
+}
+
+#ifdef CONFIG_GENERIC_BUG
+int is_valid_bugaddr(unsigned long pc)
+{
+	bug_insn_t insn;
+
+	if (pc < VMALLOC_START)
+		return 0;
+	if (get_kernel_nofault(insn, (bug_insn_t *)pc))
+		return 0;
+	if ((insn & __INSN_LENGTH_MASK) == __INSN_LENGTH_32)
+		return (insn == __BUG_INSN_32);
+	else
+		return ((insn & __COMPRESSED_INSN_MASK) == __BUG_INSN_16);
+}
+#endif /* CONFIG_GENERIC_BUG */
+
+#ifdef CONFIG_VMAP_STACK
+DEFINE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)],
+		overflow_stack)__aligned(16);
+
+asmlinkage void handle_bad_stack(struct pt_regs *regs)
+{
+	unsigned long tsk_stk = (unsigned long)current->stack;
+	unsigned long ovf_stk = (unsigned long)this_cpu_ptr(overflow_stack);
+
+	console_verbose();
+
+	pr_emerg("Insufficient stack space to handle exception!\n");
+	pr_emerg("Task stack:     [0x%016lx..0x%016lx]\n",
+			tsk_stk, tsk_stk + THREAD_SIZE);
+	pr_emerg("Overflow stack: [0x%016lx..0x%016lx]\n",
+			ovf_stk, ovf_stk + OVERFLOW_STACK_SIZE);
+
+	__show_regs(regs);
+	panic("Kernel stack overflow");
+
+	for (;;)
+		wait_for_interrupt();
+}
+#endif