signal_arm.go

Documentation: runtime

     1  // Copyright 2009 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 dragonfly || freebsd || linux || netbsd || openbsd
     6  
     7  package runtime
     8  
     9  import (
    10  	"internal/abi"
    11  	"unsafe"
    12  )
    13  
    14  func dumpregs(c *sigctxt) {
    15  	print("trap    ", hex(c.trap()), "\n")
    16  	print("error   ", hex(c.error()), "\n")
    17  	print("oldmask ", hex(c.oldmask()), "\n")
    18  	print("r0      ", hex(c.r0()), "\n")
    19  	print("r1      ", hex(c.r1()), "\n")
    20  	print("r2      ", hex(c.r2()), "\n")
    21  	print("r3      ", hex(c.r3()), "\n")
    22  	print("r4      ", hex(c.r4()), "\n")
    23  	print("r5      ", hex(c.r5()), "\n")
    24  	print("r6      ", hex(c.r6()), "\n")
    25  	print("r7      ", hex(c.r7()), "\n")
    26  	print("r8      ", hex(c.r8()), "\n")
    27  	print("r9      ", hex(c.r9()), "\n")
    28  	print("r10     ", hex(c.r10()), "\n")
    29  	print("fp      ", hex(c.fp()), "\n")
    30  	print("ip      ", hex(c.ip()), "\n")
    31  	print("sp      ", hex(c.sp()), "\n")
    32  	print("lr      ", hex(c.lr()), "\n")
    33  	print("pc      ", hex(c.pc()), "\n")
    34  	print("cpsr    ", hex(c.cpsr()), "\n")
    35  	print("fault   ", hex(c.fault()), "\n")
    36  }
    37  
    38  //go:nosplit
    39  //go:nowritebarrierrec
    40  func (c *sigctxt) sigpc() uintptr { return uintptr(c.pc()) }
    41  
    42  func (c *sigctxt) sigsp() uintptr { return uintptr(c.sp()) }
    43  func (c *sigctxt) siglr() uintptr { return uintptr(c.lr()) }
    44  
    45  // preparePanic sets up the stack to look like a call to sigpanic.
    46  func (c *sigctxt) preparePanic(sig uint32, gp *g) {
    47  	// We arrange lr, and pc to pretend the panicking
    48  	// function calls sigpanic directly.
    49  	// Always save LR to stack so that panics in leaf
    50  	// functions are correctly handled. This smashes
    51  	// the stack frame but we're not going back there
    52  	// anyway.
    53  	sp := c.sp() - 4
    54  	c.set_sp(sp)
    55  	*(*uint32)(unsafe.Pointer(uintptr(sp))) = c.lr()
    56  
    57  	pc := gp.sigpc
    58  
    59  	if shouldPushSigpanic(gp, pc, uintptr(c.lr())) {
    60  		// Make it look the like faulting PC called sigpanic.
    61  		c.set_lr(uint32(pc))
    62  	}
    63  
    64  	// In case we are panicking from external C code
    65  	c.set_r10(uint32(uintptr(unsafe.Pointer(gp))))
    66  	c.set_pc(uint32(abi.FuncPCABIInternal(sigpanic)))
    67  }
    68  
    69  func (c *sigctxt) pushCall(targetPC, resumePC uintptr) {
    70  	// Push the LR to stack, as we'll clobber it in order to
    71  	// push the call. The function being pushed is responsible
    72  	// for restoring the LR and setting the SP back.
    73  	// This extra slot is known to gentraceback.
    74  	sp := c.sp() - 4
    75  	c.set_sp(sp)
    76  	*(*uint32)(unsafe.Pointer(uintptr(sp))) = c.lr()
    77  	// Set up PC and LR to pretend the function being signaled
    78  	// calls targetPC at resumePC.
    79  	c.set_lr(uint32(resumePC))
    80  	c.set_pc(uint32(targetPC))
    81  }
    82
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