github.com/dannin/go@v0.0.0-20161031215817-d35dfd405eaa/src/runtime/signal_linux_s390x.go (about)

     1  // Copyright 2016 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  package runtime
     6  
     7  import (
     8  	"runtime/internal/sys"
     9  	"unsafe"
    10  )
    11  
    12  type sigctxt struct {
    13  	info *siginfo
    14  	ctxt unsafe.Pointer
    15  }
    16  
    17  //go:nosplit
    18  //go:nowritebarrierrec
    19  func (c *sigctxt) regs() *sigcontext {
    20  	return (*sigcontext)(unsafe.Pointer(&(*ucontext)(c.ctxt).uc_mcontext))
    21  }
    22  
    23  func (c *sigctxt) r0() uint64   { return c.regs().gregs[0] }
    24  func (c *sigctxt) r1() uint64   { return c.regs().gregs[1] }
    25  func (c *sigctxt) r2() uint64   { return c.regs().gregs[2] }
    26  func (c *sigctxt) r3() uint64   { return c.regs().gregs[3] }
    27  func (c *sigctxt) r4() uint64   { return c.regs().gregs[4] }
    28  func (c *sigctxt) r5() uint64   { return c.regs().gregs[5] }
    29  func (c *sigctxt) r6() uint64   { return c.regs().gregs[6] }
    30  func (c *sigctxt) r7() uint64   { return c.regs().gregs[7] }
    31  func (c *sigctxt) r8() uint64   { return c.regs().gregs[8] }
    32  func (c *sigctxt) r9() uint64   { return c.regs().gregs[9] }
    33  func (c *sigctxt) r10() uint64  { return c.regs().gregs[10] }
    34  func (c *sigctxt) r11() uint64  { return c.regs().gregs[11] }
    35  func (c *sigctxt) r12() uint64  { return c.regs().gregs[12] }
    36  func (c *sigctxt) r13() uint64  { return c.regs().gregs[13] }
    37  func (c *sigctxt) r14() uint64  { return c.regs().gregs[14] }
    38  func (c *sigctxt) r15() uint64  { return c.regs().gregs[15] }
    39  func (c *sigctxt) link() uint64 { return c.regs().gregs[14] }
    40  func (c *sigctxt) sp() uint64   { return c.regs().gregs[15] }
    41  
    42  //go:nosplit
    43  //go:nowritebarrierrec
    44  func (c *sigctxt) pc() uint64 { return c.regs().psw_addr }
    45  
    46  func (c *sigctxt) sigcode() uint32 { return uint32(c.info.si_code) }
    47  func (c *sigctxt) sigaddr() uint64 { return c.info.si_addr }
    48  
    49  func (c *sigctxt) set_r0(x uint64)      { c.regs().gregs[0] = x }
    50  func (c *sigctxt) set_r13(x uint64)     { c.regs().gregs[13] = x }
    51  func (c *sigctxt) set_link(x uint64)    { c.regs().gregs[14] = x }
    52  func (c *sigctxt) set_sp(x uint64)      { c.regs().gregs[15] = x }
    53  func (c *sigctxt) set_pc(x uint64)      { c.regs().psw_addr = x }
    54  func (c *sigctxt) set_sigcode(x uint32) { c.info.si_code = int32(x) }
    55  func (c *sigctxt) set_sigaddr(x uint64) {
    56  	*(*uintptr)(add(unsafe.Pointer(c.info), 2*sys.PtrSize)) = uintptr(x)
    57  }
    58  
    59  func dumpregs(c *sigctxt) {
    60  	print("r0   ", hex(c.r0()), "\t")
    61  	print("r1   ", hex(c.r1()), "\n")
    62  	print("r2   ", hex(c.r2()), "\t")
    63  	print("r3   ", hex(c.r3()), "\n")
    64  	print("r4   ", hex(c.r4()), "\t")
    65  	print("r5   ", hex(c.r5()), "\n")
    66  	print("r6   ", hex(c.r6()), "\t")
    67  	print("r7   ", hex(c.r7()), "\n")
    68  	print("r8   ", hex(c.r8()), "\t")
    69  	print("r9   ", hex(c.r9()), "\n")
    70  	print("r10  ", hex(c.r10()), "\t")
    71  	print("r11  ", hex(c.r11()), "\n")
    72  	print("r12  ", hex(c.r12()), "\t")
    73  	print("r13  ", hex(c.r13()), "\n")
    74  	print("r14  ", hex(c.r14()), "\t")
    75  	print("r15  ", hex(c.r15()), "\n")
    76  	print("pc   ", hex(c.pc()), "\t")
    77  	print("link ", hex(c.link()), "\n")
    78  }
    79  
    80  //go:nosplit
    81  //go:nowritebarrierrec
    82  func (c *sigctxt) sigpc() uintptr { return uintptr(c.pc()) }
    83  
    84  func (c *sigctxt) sigsp() uintptr { return uintptr(c.sp()) }
    85  func (c *sigctxt) siglr() uintptr { return uintptr(c.link()) }
    86  func (c *sigctxt) fault() uintptr { return uintptr(c.sigaddr()) }
    87  
    88  // preparePanic sets up the stack to look like a call to sigpanic.
    89  func (c *sigctxt) preparePanic(sig uint32, gp *g) {
    90  	// We arrange link, and pc to pretend the panicking
    91  	// function calls sigpanic directly.
    92  	// Always save LINK to stack so that panics in leaf
    93  	// functions are correctly handled. This smashes
    94  	// the stack frame but we're not going back there
    95  	// anyway.
    96  	sp := c.sp() - sys.MinFrameSize
    97  	c.set_sp(sp)
    98  	*(*uint64)(unsafe.Pointer(uintptr(sp))) = c.link()
    99  
   100  	pc := uintptr(gp.sigpc)
   101  
   102  	// If we don't recognize the PC as code
   103  	// but we do recognize the link register as code,
   104  	// then assume this was a call to non-code and treat like
   105  	// pc == 0, to make unwinding show the context.
   106  	if pc != 0 && findfunc(pc) == nil && findfunc(uintptr(c.link())) != nil {
   107  		pc = 0
   108  	}
   109  
   110  	// Don't bother saving PC if it's zero, which is
   111  	// probably a call to a nil func: the old link register
   112  	// is more useful in the stack trace.
   113  	if pc != 0 {
   114  		c.set_link(uint64(pc))
   115  	}
   116  
   117  	// In case we are panicking from external C code
   118  	c.set_r0(0)
   119  	c.set_r13(uint64(uintptr(unsafe.Pointer(gp))))
   120  	c.set_pc(uint64(funcPC(sigpanic)))
   121  }