arch/sh/kernel/traps.c

Source file repositories/reference/linux-study-clean/arch/sh/kernel/traps.c

File Facts

System
Linux kernel
Corpus path
arch/sh/kernel/traps.c
Extension
.c
Size
4140 bytes
Lines
199
Domain
Architecture Layer
Bucket
arch/sh
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

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 (get_kernel_nofault(opcode, (insn_size_t *)addr))
		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);
}

/*
 * 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

Annotation

Implementation Notes