signal_linux_s390x.go

Documentation: runtime

     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 shouldPushSigpanic(gp, pc, uintptr(c.link())) {
   103  		// Make it look the like faulting PC called sigpanic.
   104  		c.set_link(uint64(pc))
   105  	}
   106  
   107  	// In case we are panicking from external C code
   108  	c.set_r0(0)
   109  	c.set_r13(uint64(uintptr(unsafe.Pointer(gp))))
   110  	c.set_pc(uint64(funcPC(sigpanic)))
   111  }
   112  
   113  func (c *sigctxt) pushCall(targetPC, resumePC uintptr) {
   114  	// Push the LR to stack, as we'll clobber it in order to
   115  	// push the call. The function being pushed is responsible
   116  	// for restoring the LR and setting the SP back.
   117  	// This extra slot is known to gentraceback.
   118  	sp := c.sp() - 8
   119  	c.set_sp(sp)
   120  	*(*uint64)(unsafe.Pointer(uintptr(sp))) = c.link()
   121  	// Set up PC and LR to pretend the function being signaled
   122  	// calls targetPC at resumePC.
   123  	c.set_link(uint64(resumePC))
   124  	c.set_pc(uint64(targetPC))
   125  }
   126
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