signal_arm64.go

Documentation: runtime

     1  // Copyright 2014 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  //go:build darwin || freebsd || linux || netbsd || openbsd
     6  
     7  package runtime
     8  
     9  import (
    10  	"internal/abi"
    11  	"internal/goarch"
    12  	"runtime/internal/sys"
    13  	"unsafe"
    14  )
    15  
    16  func dumpregs(c *sigctxt) {
    17  	print("r0      ", hex(c.r0()), "\n")
    18  	print("r1      ", hex(c.r1()), "\n")
    19  	print("r2      ", hex(c.r2()), "\n")
    20  	print("r3      ", hex(c.r3()), "\n")
    21  	print("r4      ", hex(c.r4()), "\n")
    22  	print("r5      ", hex(c.r5()), "\n")
    23  	print("r6      ", hex(c.r6()), "\n")
    24  	print("r7      ", hex(c.r7()), "\n")
    25  	print("r8      ", hex(c.r8()), "\n")
    26  	print("r9      ", hex(c.r9()), "\n")
    27  	print("r10     ", hex(c.r10()), "\n")
    28  	print("r11     ", hex(c.r11()), "\n")
    29  	print("r12     ", hex(c.r12()), "\n")
    30  	print("r13     ", hex(c.r13()), "\n")
    31  	print("r14     ", hex(c.r14()), "\n")
    32  	print("r15     ", hex(c.r15()), "\n")
    33  	print("r16     ", hex(c.r16()), "\n")
    34  	print("r17     ", hex(c.r17()), "\n")
    35  	print("r18     ", hex(c.r18()), "\n")
    36  	print("r19     ", hex(c.r19()), "\n")
    37  	print("r20     ", hex(c.r20()), "\n")
    38  	print("r21     ", hex(c.r21()), "\n")
    39  	print("r22     ", hex(c.r22()), "\n")
    40  	print("r23     ", hex(c.r23()), "\n")
    41  	print("r24     ", hex(c.r24()), "\n")
    42  	print("r25     ", hex(c.r25()), "\n")
    43  	print("r26     ", hex(c.r26()), "\n")
    44  	print("r27     ", hex(c.r27()), "\n")
    45  	print("r28     ", hex(c.r28()), "\n")
    46  	print("r29     ", hex(c.r29()), "\n")
    47  	print("lr      ", hex(c.lr()), "\n")
    48  	print("sp      ", hex(c.sp()), "\n")
    49  	print("pc      ", hex(c.pc()), "\n")
    50  	print("fault   ", hex(c.fault()), "\n")
    51  }
    52  
    53  //go:nosplit
    54  //go:nowritebarrierrec
    55  func (c *sigctxt) sigpc() uintptr { return uintptr(c.pc()) }
    56  
    57  func (c *sigctxt) setsigpc(x uint64) { c.set_pc(x) }
    58  func (c *sigctxt) sigsp() uintptr    { return uintptr(c.sp()) }
    59  func (c *sigctxt) siglr() uintptr    { return uintptr(c.lr()) }
    60  
    61  // preparePanic sets up the stack to look like a call to sigpanic.
    62  func (c *sigctxt) preparePanic(sig uint32, gp *g) {
    63  	// We arrange lr, and pc to pretend the panicking
    64  	// function calls sigpanic directly.
    65  	// Always save LR to stack so that panics in leaf
    66  	// functions are correctly handled. This smashes
    67  	// the stack frame but we're not going back there
    68  	// anyway.
    69  	sp := c.sp() - sys.StackAlign // needs only sizeof uint64, but must align the stack
    70  	c.set_sp(sp)
    71  	*(*uint64)(unsafe.Pointer(uintptr(sp))) = c.lr()
    72  	// Make sure a valid frame pointer is saved on the stack so that the
    73  	// frame pointer checks in adjustframe are happy, if they're enabled.
    74  	// Frame pointer unwinding won't visit the sigpanic frame, since
    75  	// sigpanic will save the same frame pointer before calling into a panic
    76  	// function.
    77  	*(*uint64)(unsafe.Pointer(uintptr(sp - goarch.PtrSize))) = c.r29()
    78  
    79  	pc := gp.sigpc
    80  
    81  	if shouldPushSigpanic(gp, pc, uintptr(c.lr())) {
    82  		// Make it look the like faulting PC called sigpanic.
    83  		c.set_lr(uint64(pc))
    84  	}
    85  
    86  	// In case we are panicking from external C code
    87  	c.set_r28(uint64(uintptr(unsafe.Pointer(gp))))
    88  	c.set_pc(uint64(abi.FuncPCABIInternal(sigpanic)))
    89  }
    90  
    91  func (c *sigctxt) pushCall(targetPC, resumePC uintptr) {
    92  	// Push the LR to stack, as we'll clobber it in order to
    93  	// push the call. The function being pushed is responsible
    94  	// for restoring the LR and setting the SP back.
    95  	// This extra space is known to gentraceback.
    96  	sp := c.sp() - 16 // SP needs 16-byte alignment
    97  	c.set_sp(sp)
    98  	*(*uint64)(unsafe.Pointer(uintptr(sp))) = c.lr()
    99  	// Make sure a valid frame pointer is saved on the stack so that the
   100  	// frame pointer checks in adjustframe are happy, if they're enabled.
   101  	// This is not actually used for unwinding.
   102  	*(*uint64)(unsafe.Pointer(uintptr(sp - goarch.PtrSize))) = c.r29()
   103  	// Set up PC and LR to pretend the function being signaled
   104  	// calls targetPC at resumePC.
   105  	c.set_lr(uint64(resumePC))
   106  	c.set_pc(uint64(targetPC))
   107  }
   108
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