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#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/uaccess.h>
#include <asm/unwinder.h>
#include <asm/system.h>
#ifdef CONFIG_BUG
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(ctrl_inw(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(ctrl_inw(regs->pc - 4));
if (notify_die(DIE_TRAP, "bug trap", regs, 0, TRAPA_BUG_OPCODE & 0xff,
SIGTRAP) == NOTIFY_STOP)
return;
#ifdef CONFIG_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);
}
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