diff options
Diffstat (limited to 'arch/sh/kernel/traps.c')
| -rw-r--r-- | arch/sh/kernel/traps.c | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/arch/sh/kernel/traps.c b/arch/sh/kernel/traps.c new file mode 100644 index 000000000..8b49cced6 --- /dev/null +++ b/arch/sh/kernel/traps.c @@ -0,0 +1,193 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/bug.h> +#include <linux/io.h> +#include <linux/types.h> +#include <linux/kdebug.h> +#include <linux/signal.h> +#include <linux/sched.h> +#include <linux/sched/debug.h> +#include <linux/sched/task_stack.h> +#include <linux/uaccess.h> +#include <linux/hardirq.h> +#include <linux/kernel.h> +#include <linux/kexec.h> +#include <linux/sched/signal.h> + +#include <linux/extable.h> +#include <linux/module.h> /* print_modules */ +#include <asm/unwinder.h> +#include <asm/traps.h> + +static DEFINE_SPINLOCK(die_lock); + +void die(const char *str, struct pt_regs *regs, long err) +{ + static int die_counter; + + oops_enter(); + + spin_lock_irq(&die_lock); + console_verbose(); + bust_spinlocks(1); + + printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter); + print_modules(); + show_regs(regs); + + printk("Process: %s (pid: %d, stack limit = %p)\n", current->comm, + task_pid_nr(current), task_stack_page(current) + 1); + + if (!user_mode(regs) || in_interrupt()) + dump_mem("Stack: ", regs->regs[15], THREAD_SIZE + + (unsigned long)task_stack_page(current)); + + notify_die(DIE_OOPS, str, regs, err, 255, SIGSEGV); + + bust_spinlocks(0); + add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); + spin_unlock_irq(&die_lock); + oops_exit(); + + if (kexec_should_crash(current)) + crash_kexec(regs); + + if (in_interrupt()) + panic("Fatal exception in interrupt"); + + if (panic_on_oops) + panic("Fatal exception"); + + do_exit(SIGSEGV); +} + +void die_if_kernel(const char *str, struct pt_regs *regs, long err) +{ + if (!user_mode(regs)) + die(str, regs, err); +} + +/* + * try and fix up kernelspace address errors + * - userspace errors just cause EFAULT to be returned, resulting in SEGV + * - kernel/userspace interfaces cause a jump to an appropriate handler + * - other kernel errors are bad + */ +void die_if_no_fixup(const char *str, struct pt_regs *regs, long err) +{ + if (!user_mode(regs)) { + const struct exception_table_entry *fixup; + fixup = search_exception_tables(regs->pc); + if (fixup) { + regs->pc = fixup->fixup; + return; + } + + die(str, regs, err); + } +} + +#ifdef CONFIG_GENERIC_BUG +static void handle_BUG(struct pt_regs *regs) +{ + const struct bug_entry *bug; + unsigned long bugaddr = regs->pc; + enum bug_trap_type tt; + + if (!is_valid_bugaddr(bugaddr)) + goto invalid; + + bug = find_bug(bugaddr); + + /* Switch unwinders when unwind_stack() is called */ + if (bug->flags & BUGFLAG_UNWINDER) + unwinder_faulted = 1; + + tt = report_bug(bugaddr, regs); + if (tt == BUG_TRAP_TYPE_WARN) { + regs->pc += instruction_size(bugaddr); + return; + } + +invalid: + die("Kernel BUG", regs, TRAPA_BUG_OPCODE & 0xff); +} + +int is_valid_bugaddr(unsigned long addr) +{ + insn_size_t opcode; + + if (addr < PAGE_OFFSET) + return 0; + if (probe_kernel_address((insn_size_t *)addr, opcode)) + return 0; + if (opcode == TRAPA_BUG_OPCODE) + return 1; + + return 0; +} +#endif + +/* + * Generic trap handler. + */ +BUILD_TRAP_HANDLER(debug) +{ + TRAP_HANDLER_DECL; + + /* Rewind */ + regs->pc -= instruction_size(__raw_readw(regs->pc - 4)); + + if (notify_die(DIE_TRAP, "debug trap", regs, 0, vec & 0xff, + SIGTRAP) == NOTIFY_STOP) + return; + + force_sig(SIGTRAP, current); +} + +/* + * Special handler for BUG() traps. + */ +BUILD_TRAP_HANDLER(bug) +{ + TRAP_HANDLER_DECL; + + /* Rewind */ + regs->pc -= instruction_size(__raw_readw(regs->pc - 4)); + + if (notify_die(DIE_TRAP, "bug trap", regs, 0, TRAPA_BUG_OPCODE & 0xff, + SIGTRAP) == NOTIFY_STOP) + return; + +#ifdef CONFIG_GENERIC_BUG + if (__kernel_text_address(instruction_pointer(regs))) { + insn_size_t insn = *(insn_size_t *)instruction_pointer(regs); + if (insn == TRAPA_BUG_OPCODE) + handle_BUG(regs); + return; + } +#endif + + force_sig(SIGTRAP, current); +} + +BUILD_TRAP_HANDLER(nmi) +{ + unsigned int cpu = smp_processor_id(); + TRAP_HANDLER_DECL; + + nmi_enter(); + nmi_count(cpu)++; + + switch (notify_die(DIE_NMI, "NMI", regs, 0, vec & 0xff, SIGINT)) { + case NOTIFY_OK: + case NOTIFY_STOP: + break; + case NOTIFY_BAD: + die("Fatal Non-Maskable Interrupt", regs, SIGINT); + default: + printk(KERN_ALERT "Got NMI, but nobody cared. Ignoring...\n"); + break; + } + + nmi_exit(); +} |