.globl  __vectors_start
__vectors_start:ARM(    swi SYS_ERROR0  )THUMB( svc #0      )THUMB( nop         )W(b)   vector_und + stubs_offsetW(ldr)    pc, .LCvswi + stubs_offsetW(b) vector_pabt + stubs_offsetW(b) vector_dabt + stubs_offsetW(b) vector_addrexcptn + stubs_offsetW(b)   vector_irq + stubs_offsetW(b)  vector_fiq + stubs_offset.globl    __vectors_end

/** Data abort dispatcher* Enter in ABT mode, spsr = USR CPSR, lr = USR PC*/vector_stub    dabt, ABT_MODE, 8.long  __dabt_usr          @  0  (USR_26 / USR_32).long   __dabt_invalid          @  1  (FIQ_26 / FIQ_32).long   __dabt_invalid          @  2  (IRQ_26 / IRQ_32).long   __dabt_svc          @  3  (SVC_26 / SVC_32).long   __dabt_invalid          @  4.long  __dabt_invalid          @  5.long  __dabt_invalid          @  6.long  __dabt_invalid          @  7.long  __dabt_invalid          @  8.long  __dabt_invalid          @  9.long  __dabt_invalid          @  a.long  __dabt_invalid          @  b.long  __dabt_invalid          @  c.long  __dabt_invalid          @  d.long  __dabt_invalid          @  e.long  __dabt_invalid          @  f

/** Vector stubs.** This code is copied to 0xffff0200 so we can use branches in the* vectors, rather than ldr's.  Note that this code must not* exceed 0x300 bytes.** Common stub entry macro:*   Enter in IRQ mode, spsr = SVC/USR CPSR, lr = SVC/USR PC** SP points to a minimal amount of processor-private memory, the address* of which is copied into r0 for the mode specific abort handler.*/.macro    vector_stub, name, mode, correction=0.align    5vector_\name:.if \correctionsub    lr, lr, #\correction.endif@@ Save r0, lr_<exception> (parent PC) and spsr_<exception>@ (parent CPSR)@stmia    sp, {r0, lr}        @ save r0, lrmrs    lr, spsr　　　　　　　　　 @保存跳转之前的CPSR到lr寄存器str    lr, [sp, #8]        @ save spsr@@ Prepare for SVC32 mode.  IRQs remain disabled.@mrs    r0, cpsreor    r0, r0, #(\mode ^ SVC_MODE | PSR_ISETSTATE)msr    spsr_cxsf, r0           @准备进入svc模式@@ the branch table must immediately follow this code@and    lr, lr, #0x0f          @得到跳转前所处的模式（usr、svr等）THUMB(    adr    r0, 1f            )THUMB(    ldr    lr, [r0, lr, lsl #2]    )mov    r0, sp                   ARM(    ldr    lr, [pc, lr, lsl #2]    ) @根据模式跳转到相应的data abort指令，并进入svc模式movs    pc, lr            @ branch to handler in SVC mode
ENDPROC(vector_\name).align    2@ handler addresses follow this label
1:.endm

__dabt_svc:svc_entrymov    r2, spdabt_helper@@ IRQs off again before pulling preserved data off the stack@disable_irq_notrace#ifdef CONFIG_TRACE_IRQFLAGStst    r5, #PSR_I_BITbleq    trace_hardirqs_ontst    r5, #PSR_I_BITblne    trace_hardirqs_off
#endifsvc_exit r5                @ return from exceptionUNWIND(.fnend        )
ENDPROC(__dabt_svc)

.macro    dabt_helper@@ Call the processor-specific abort handler:@@  r2 - pt_regs@  r4 - aborted context pc@  r5 - aborted context psr@@ The abort handler must return the aborted address in r0, and@ the fault status register in r1.  r9 must be preserved.@
#ifdef MULTI_DABORTldr    ip, .LCprocfnsmov    lr, pcldr    pc, [ip, #PROCESSOR_DABT_FUNC]
#elsebl    CPU_DABORT_HANDLER
#endif.endm#ifdef CONFIG_KPROBES.section    .kprobes.text,"ax",%progbits
#else.text
#endif

#  define CPU_DABORT_HANDLER v6_early_abort

ENTRY(v6_early_abort)mrc    p15, 0, r1, c5, c0, 0       @ get FSRmrc   p15, 0, r0, c6, c0, 0       @ get FARb do_DataAbort

asmlinkage void __exception
do_DataAbort(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
{const struct fsr_info *inf = fsr_info + fsr_fs(fsr);struct siginfo info;if (!inf->fn(addr, fsr & ~FSR_LNX_PF, regs))return;printk(KERN_ALERT "Unhandled fault: %s (0x%03x) at 0x%08lx\n",inf->name, fsr, addr);info.si_signo = inf->sig;info.si_errno = 0;info.si_code  = inf->code;info.si_addr  = (void __user *)addr;arm_notify_die("", regs, &info, fsr, 0);
}

struct fsr_info {int (*fn)(unsigned long addr, unsigned int fsr, struct pt_regs *regs);int   sig;int code;const char *name;
};

static struct fsr_info fsr_info[] = {{ do_bad,      SIGBUS,  0,     "unknown 0"           },{ do_bad,     SIGBUS,  0,     "unknown 1"           },{ do_bad,     SIGBUS,  0,     "unknown 2"           },{ do_bad,     SIGBUS,  0,     "unknown 3"           },{ do_bad,     SIGBUS,  0,     "reserved translation fault"  },{ do_translation_fault,   SIGSEGV, SEGV_MAPERR,   "level 1 translation fault"   },{ do_translation_fault,   SIGSEGV, SEGV_MAPERR,   "level 2 translation fault"   },{ do_page_fault,  SIGSEGV, SEGV_MAPERR,   "level 3 translation fault"   },{ do_bad,     SIGBUS,  0,     "reserved access flag fault"  },{ do_bad,     SIGSEGV, SEGV_ACCERR,   "level 1 access flag fault"   },{ do_bad,     SIGSEGV, SEGV_ACCERR,   "level 2 access flag fault"   },{ do_page_fault,  SIGSEGV, SEGV_ACCERR,   "level 3 access flag fault"   },......

static int
do_bad(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
{return 1;
}

void arm_notify_die(const char *str, struct pt_regs *regs,struct siginfo *info, unsigned long err, unsigned long trap)
{if (user_mode(regs)) {current->thread.error_code = err;current->thread.trap_no = trap;force_sig_info(info->si_signo, info, current);} else {die(str, regs, err);}
}