[mirror_ubuntu-jammy-kernel.git] / arch / riscv / kernel / traps.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2012 Regents of the University of California
 */

#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/mm.h>
#include <linux/module.h>
#include <linux/irq.h>

#include <asm/processor.h>
#include <asm/ptrace.h>
#include <asm/csr.h>

int show_unhandled_signals = 1;

extern asmlinkage void handle_exception(void);

static DEFINE_SPINLOCK(die_lock);

void die(struct pt_regs *regs, const char *str)
{
	static int die_counter;
	int ret;

	oops_enter();

	spin_lock_irq(&die_lock);
	console_verbose();
	bust_spinlocks(1);

	pr_emerg("%s [#%d]\n", str, ++die_counter);
	print_modules();
	show_regs(regs);

	ret = notify_die(DIE_OOPS, str, regs, 0, regs->scause, SIGSEGV);

	bust_spinlocks(0);
	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
	spin_unlock_irq(&die_lock);
	oops_exit();

	if (in_interrupt())
		panic("Fatal exception in interrupt");
	if (panic_on_oops)
		panic("Fatal exception");
	if (ret != NOTIFY_STOP)
		do_exit(SIGSEGV);
}

void do_trap(struct pt_regs *regs, int signo, int code,
	unsigned long addr, struct task_struct *tsk)
{
	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, tsk);
}

static void do_trap_error(struct pt_regs *regs, int signo, int code,
	unsigned long addr, const char *str)
{
	if (user_mode(regs)) {
		do_trap(regs, signo, code, addr, current);
	} else {
		if (!fixup_exception(regs))
			die(regs, str);
	}
}

#define DO_ERROR_INFO(name, signo, code, str)				\
asmlinkage void name(struct pt_regs *regs)				\
{									\
	do_trap_error(regs, signo, code, regs->sepc, "Oops - " str);	\
}

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");
DO_ERROR_INFO(do_trap_insn_illegal,
	SIGILL, ILL_ILLOPC, "illegal instruction");
DO_ERROR_INFO(do_trap_load_misaligned,
	SIGBUS, BUS_ADRALN, "load address misaligned");
DO_ERROR_INFO(do_trap_load_fault,
	SIGSEGV, SEGV_ACCERR, "load access fault");
DO_ERROR_INFO(do_trap_store_misaligned,
	SIGBUS, BUS_ADRALN, "store (or AMO) address misaligned");
DO_ERROR_INFO(do_trap_store_fault,
	SIGSEGV, SEGV_ACCERR, "store (or AMO) access fault");
DO_ERROR_INFO(do_trap_ecall_u,
	SIGILL, ILL_ILLTRP, "environment call from U-mode");
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");

#ifdef CONFIG_GENERIC_BUG
static inline unsigned long get_break_insn_length(unsigned long pc)
{
	bug_insn_t insn;

	if (probe_kernel_address((bug_insn_t *)pc, insn))
		return 0;
	return (((insn & __INSN_LENGTH_MASK) == __INSN_LENGTH_32) ? 4UL : 2UL);
}
#endif /* CONFIG_GENERIC_BUG */

asmlinkage void do_trap_break(struct pt_regs *regs)
{
#ifdef CONFIG_GENERIC_BUG
	if (!user_mode(regs)) {
		enum bug_trap_type type;

		type = report_bug(regs->sepc, regs);
		switch (type) {
		case BUG_TRAP_TYPE_NONE:
			break;
		case BUG_TRAP_TYPE_WARN:
			regs->sepc += get_break_insn_length(regs->sepc);
			break;
		case BUG_TRAP_TYPE_BUG:
			die(regs, "Kernel BUG");
		}
	}
#endif /* CONFIG_GENERIC_BUG */

	force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)(regs->sepc), current);
}

#ifdef CONFIG_GENERIC_BUG
int is_valid_bugaddr(unsigned long pc)
{
	bug_insn_t insn;

	if (pc < VMALLOC_START)
		return 0;
	if (probe_kernel_address((bug_insn_t *)pc, insn))
		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 */

void __init trap_init(void)
{
	/*
	 * Set sup0 scratch register to 0, indicating to exception vector
	 * that we are presently executing in the kernel
	 */
	csr_write(CSR_SSCRATCH, 0);
	/* Set the exception vector address */
	csr_write(CSR_STVEC, &handle_exception);
	/* Enable all interrupts */
	csr_write(CSR_SIE, -1);
}
Commit	Line	Data
50acfb2b	1	// SPDX-License-Identifier: GPL-2.0-only
76d2a049 PD	2	/*
76d2a049 PD	3	* Copyright (C) 2012 Regents of the University of California
76d2a049 PD	4	*/
	5
	6	#include <linux/kernel.h>
	7	#include <linux/init.h>
	8	#include <linux/sched.h>
	9	#include <linux/sched/debug.h>
	10	#include <linux/sched/signal.h>
	11	#include <linux/signal.h>
	12	#include <linux/kdebug.h>
	13	#include <linux/uaccess.h>
	14	#include <linux/mm.h>
	15	#include <linux/module.h>
	16	#include <linux/irq.h>
	17
	18	#include <asm/processor.h>
	19	#include <asm/ptrace.h>
	20	#include <asm/csr.h>
	21
	22	int show_unhandled_signals = 1;
	23
	24	extern asmlinkage void handle_exception(void);
	25
	26	static DEFINE_SPINLOCK(die_lock);
	27
	28	void die(struct pt_regs regs, const char str)
	29	{
	30	static int die_counter;
	31	int ret;
	32
	33	oops_enter();
	34
	35	spin_lock_irq(&die_lock);
	36	console_verbose();
	37	bust_spinlocks(1);
	38
	39	pr_emerg("%s [#%d]\n", str, ++die_counter);
	40	print_modules();
	41	show_regs(regs);
	42
	43	ret = notify_die(DIE_OOPS, str, regs, 0, regs->scause, SIGSEGV);
	44
	45	bust_spinlocks(0);
	46	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
	47	spin_unlock_irq(&die_lock);
	48	oops_exit();
	49
	50	if (in_interrupt())
	51	panic("Fatal exception in interrupt");
	52	if (panic_on_oops)
	53	panic("Fatal exception");
	54	if (ret != NOTIFY_STOP)
	55	do_exit(SIGSEGV);
	56	}
	57
76d2a049 PD	58	void do_trap(struct pt_regs *regs, int signo, int code,
	59	unsigned long addr, struct task_struct *tsk)
	60	{
	61	if (show_unhandled_signals && unhandled_signal(tsk, signo)
	62	&& printk_ratelimit()) {
	63	pr_info("%s[%d]: unhandled signal %d code 0x%x at 0x" REG_FMT,
	64	tsk->comm, task_pid_nr(tsk), signo, code, addr);
6ab77af4	65	print_vma_addr(KERN_CONT " in ", instruction_pointer(regs));
76d2a049 PD	66	pr_cont("\n");
	67	show_regs(regs);
	68	}
	69
7ff3a762	70	force_sig_fault(signo, code, (void __user *)addr, tsk);
76d2a049 PD	71	}
	72
	73	static void do_trap_error(struct pt_regs *regs, int signo, int code,
	74	unsigned long addr, const char *str)
	75	{
	76	if (user_mode(regs)) {
	77	do_trap(regs, signo, code, addr, current);
	78	} else {
	79	if (!fixup_exception(regs))
	80	die(regs, str);
	81	}
	82	}
	83
	84	#define DO_ERROR_INFO(name, signo, code, str) \
	85	asmlinkage void name(struct pt_regs *regs) \
	86	{ \
	87	do_trap_error(regs, signo, code, regs->sepc, "Oops - " str); \
	88	}
	89
	90	DO_ERROR_INFO(do_trap_unknown,
	91	SIGILL, ILL_ILLTRP, "unknown exception");
	92	DO_ERROR_INFO(do_trap_insn_misaligned,
	93	SIGBUS, BUS_ADRALN, "instruction address misaligned");
	94	DO_ERROR_INFO(do_trap_insn_fault,
	95	SIGSEGV, SEGV_ACCERR, "instruction access fault");
	96	DO_ERROR_INFO(do_trap_insn_illegal,
	97	SIGILL, ILL_ILLOPC, "illegal instruction");
	98	DO_ERROR_INFO(do_trap_load_misaligned,
	99	SIGBUS, BUS_ADRALN, "load address misaligned");
	100	DO_ERROR_INFO(do_trap_load_fault,
	101	SIGSEGV, SEGV_ACCERR, "load access fault");
	102	DO_ERROR_INFO(do_trap_store_misaligned,
	103	SIGBUS, BUS_ADRALN, "store (or AMO) address misaligned");
	104	DO_ERROR_INFO(do_trap_store_fault,
	105	SIGSEGV, SEGV_ACCERR, "store (or AMO) access fault");
	106	DO_ERROR_INFO(do_trap_ecall_u,
	107	SIGILL, ILL_ILLTRP, "environment call from U-mode");
	108	DO_ERROR_INFO(do_trap_ecall_s,
	109	SIGILL, ILL_ILLTRP, "environment call from S-mode");
	110	DO_ERROR_INFO(do_trap_ecall_m,
	111	SIGILL, ILL_ILLTRP, "environment call from M-mode");
	112
ee72e0e7 VC	113	#ifdef CONFIG_GENERIC_BUG
	114	static inline unsigned long get_break_insn_length(unsigned long pc)
	115	{
	116	bug_insn_t insn;
	117
	118	if (probe_kernel_address((bug_insn_t *)pc, insn))
	119	return 0;
	120	return (((insn & __INSN_LENGTH_MASK) == __INSN_LENGTH_32) ? 4UL : 2UL);
	121	}
	122	#endif /* CONFIG_GENERIC_BUG */
	123
76d2a049 PD	124	asmlinkage void do_trap_break(struct pt_regs *regs)
	125	{
	126	#ifdef CONFIG_GENERIC_BUG
	127	if (!user_mode(regs)) {
	128	enum bug_trap_type type;
	129
	130	type = report_bug(regs->sepc, regs);
	131	switch (type) {
	132	case BUG_TRAP_TYPE_NONE:
	133	break;
	134	case BUG_TRAP_TYPE_WARN:
ee72e0e7 VC	135	regs->sepc += get_break_insn_length(regs->sepc);
ee72e0e7 VC	136	break;
76d2a049 PD	137	case BUG_TRAP_TYPE_BUG:
	138	die(regs, "Kernel BUG");
	139	}
	140	}
	141	#endif /* CONFIG_GENERIC_BUG */
	142
7ff3a762	143	force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)(regs->sepc), current);
76d2a049 PD	144	}
	145
	146	#ifdef CONFIG_GENERIC_BUG
	147	int is_valid_bugaddr(unsigned long pc)
	148	{
	149	bug_insn_t insn;
	150
9a6e7af0	151	if (pc < VMALLOC_START)
76d2a049	152	return 0;
9bf97390	153	if (probe_kernel_address((bug_insn_t *)pc, insn))
76d2a049	154	return 0;
ee72e0e7 VC	155	if ((insn & __INSN_LENGTH_MASK) == __INSN_LENGTH_32)
	156	return (insn == __BUG_INSN_32);
	157	else
	158	return ((insn & __COMPRESSED_INSN_MASK) == __BUG_INSN_16);
76d2a049 PD	159	}
	160	#endif /* CONFIG_GENERIC_BUG */
	161
	162	void __init trap_init(void)
	163	{
	164	/*
	165	* Set sup0 scratch register to 0, indicating to exception vector
	166	* that we are presently executing in the kernel
	167	*/
a3182c91	168	csr_write(CSR_SSCRATCH, 0);
76d2a049	169	/* Set the exception vector address */
a3182c91	170	csr_write(CSR_STVEC, &handle_exception);
76d2a049	171	/* Enable all interrupts */
a3182c91	172	csr_write(CSR_SIE, -1);
76d2a049	173	}