signal_darwin_arm64.go

     1  // Copyright 2015 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 "unsafe"
     8  
     9  type sigctxt struct {
    10  	info *siginfo
    11  	ctxt unsafe.Pointer
    12  }
    13  
    14  //go:nosplit
    15  //go:nowritebarrierrec
    16  func (c *sigctxt) regs() *regs64 { return &(*ucontext)(c.ctxt).uc_mcontext.ss }
    17  
    18  func (c *sigctxt) r0() uint64  { return c.regs().x[0] }
    19  func (c *sigctxt) r1() uint64  { return c.regs().x[1] }
    20  func (c *sigctxt) r2() uint64  { return c.regs().x[2] }
    21  func (c *sigctxt) r3() uint64  { return c.regs().x[3] }
    22  func (c *sigctxt) r4() uint64  { return c.regs().x[4] }
    23  func (c *sigctxt) r5() uint64  { return c.regs().x[5] }
    24  func (c *sigctxt) r6() uint64  { return c.regs().x[6] }
    25  func (c *sigctxt) r7() uint64  { return c.regs().x[7] }
    26  func (c *sigctxt) r8() uint64  { return c.regs().x[8] }
    27  func (c *sigctxt) r9() uint64  { return c.regs().x[9] }
    28  func (c *sigctxt) r10() uint64 { return c.regs().x[10] }
    29  func (c *sigctxt) r11() uint64 { return c.regs().x[11] }
    30  func (c *sigctxt) r12() uint64 { return c.regs().x[12] }
    31  func (c *sigctxt) r13() uint64 { return c.regs().x[13] }
    32  func (c *sigctxt) r14() uint64 { return c.regs().x[14] }
    33  func (c *sigctxt) r15() uint64 { return c.regs().x[15] }
    34  func (c *sigctxt) r16() uint64 { return c.regs().x[16] }
    35  func (c *sigctxt) r17() uint64 { return c.regs().x[17] }
    36  func (c *sigctxt) r18() uint64 { return c.regs().x[18] }
    37  func (c *sigctxt) r19() uint64 { return c.regs().x[19] }
    38  func (c *sigctxt) r20() uint64 { return c.regs().x[20] }
    39  func (c *sigctxt) r21() uint64 { return c.regs().x[21] }
    40  func (c *sigctxt) r22() uint64 { return c.regs().x[22] }
    41  func (c *sigctxt) r23() uint64 { return c.regs().x[23] }
    42  func (c *sigctxt) r24() uint64 { return c.regs().x[24] }
    43  func (c *sigctxt) r25() uint64 { return c.regs().x[25] }
    44  func (c *sigctxt) r26() uint64 { return c.regs().x[26] }
    45  func (c *sigctxt) r27() uint64 { return c.regs().x[27] }
    46  func (c *sigctxt) r28() uint64 { return c.regs().x[28] }
    47  func (c *sigctxt) r29() uint64 { return c.regs().fp }
    48  func (c *sigctxt) lr() uint64  { return c.regs().lr }
    49  func (c *sigctxt) sp() uint64  { return c.regs().sp }
    50  
    51  //go:nosplit
    52  //go:nowritebarrierrec
    53  func (c *sigctxt) pc() uint64 { return c.regs().pc }
    54  
    55  func (c *sigctxt) fault() uintptr { return uintptr(unsafe.Pointer(c.info.si_addr)) }
    56  
    57  func (c *sigctxt) sigcode() uint64 { return uint64(c.info.si_code) }
    58  func (c *sigctxt) sigaddr() uint64 { return uint64(uintptr(unsafe.Pointer(c.info.si_addr))) }
    59  
    60  func (c *sigctxt) set_pc(x uint64)  { c.regs().pc = x }
    61  func (c *sigctxt) set_sp(x uint64)  { c.regs().sp = x }
    62  func (c *sigctxt) set_lr(x uint64)  { c.regs().lr = x }
    63  func (c *sigctxt) set_r28(x uint64) { c.regs().x[28] = x }
    64  
    65  func (c *sigctxt) set_sigcode(x uint64) { c.info.si_code = int32(x) }
    66  func (c *sigctxt) set_sigaddr(x uint64) {
    67  	c.info.si_addr = (*byte)(unsafe.Pointer(uintptr(x)))
    68  }
    69  
    70  //go:nosplit
    71  func (c *sigctxt) fixsigcode(sig uint32) {
    72  	switch sig {
    73  	case _SIGTRAP:
    74  		// OS X sets c.sigcode() == TRAP_BRKPT unconditionally for all SIGTRAPs,
    75  		// leaving no way to distinguish a breakpoint-induced SIGTRAP
    76  		// from an asynchronous signal SIGTRAP.
    77  		// They all look breakpoint-induced by default.
    78  		// Try looking at the code to see if it's a breakpoint.
    79  		// The assumption is that we're very unlikely to get an
    80  		// asynchronous SIGTRAP at just the moment that the
    81  		// PC started to point at unmapped memory.
    82  		pc := uintptr(c.pc())
    83  		// OS X will leave the pc just after the instruction.
    84  		code := (*uint32)(unsafe.Pointer(pc - 4))
    85  		if *code != 0xd4200000 {
    86  			// SIGTRAP on something other than breakpoint.
    87  			c.set_sigcode(_SI_USER)
    88  		}
    89  	}
    90  }
    91
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