// the runtime, but operations like a slice copy can call msanread
// anyhow for values on the stack. Just ignore msanread when running
// on the system stack. The other msan functions are fine.
//
//go:linkname msanread
//go:nosplit
func msanread(addr unsafe.Pointer, sz uintptr) {
	gp := getg()
	if gp == nil || gp.m == nil || gp == gp.m.g0 || gp == gp.m.gsignal {
		return
	}
	domsanread(addr, sz)
}

//go:noescape

// license that can be found in the LICENSE file.

//go:build msan

package msan

import (
	"unsafe"
)

const Enabled = true

//go:linkname Read runtime.msanread
func Read(addr unsafe.Pointer, sz uintptr)

//go:linkname Write runtime.msanwrite
func Write(addr unsafe.Pointer, sz uintptr)

//go:linkname Malloc runtime.msanmalloc
func Malloc(addr unsafe.Pointer, sz uintptr)

package runtime

import (
	"unsafe"
)

const msanenabled = false

// Because msanenabled is false, none of these functions should be called.

func msanread(addr unsafe.Pointer, sz uintptr)     { throw("msan") }
func msanwrite(addr unsafe.Pointer, sz uintptr)    { throw("msan") }
func msanmalloc(addr unsafe.Pointer, sz uintptr)   { throw("msan") }

	Duffcopy          *obj.LSym
	Duffzero          *obj.LSym
	GCWriteBarrier    [8]*obj.LSym
	Goschedguarded    *obj.LSym
	Growslice         *obj.LSym
	InterfaceSwitch   *obj.LSym
	Memmove           *obj.LSym
	Msanread          *obj.LSym
	Msanwrite         *obj.LSym
	Msanmove          *obj.LSym
	Newobject         *obj.LSym
	Newproc           *obj.LSym
	Panicdivide       *obj.LSym
	Panicshift        *obj.LSym

// the stack as uninitialized.
//
//go:noinline
func F1() uintptr {
	s := C.f()
	return uintptr(s.a[0])
}

// F2 allocates a struct on the stack and converts it to an empty interface,
// which will call msanread and see that the data appears uninitialized.
//
//go:noinline
func F2() interface{} {
	return C.S{}
}

func poisonStack(i int) int {
	if i == 0 {
		return int(F1())
	}
	F1()

		}
	}

	if raceenabled {
		callerpc := getcallerpc()
		pc := abi.FuncPCABIInternal(makeslicecopy)
		racereadrangepc(from, copymem, callerpc, pc)
	}
	if msanenabled {
		msanread(from, copymem)
	}
	if asanenabled {
		asanread(from, copymem)
	}

	memmove(to, from, copymem)

	return to
}

// makeslice should be an internal detail,
// but widely used packages access it using linkname.

//go:build msan

#include "go_asm.h"
#include "textflag.h"

#define RARG0 R0
#define RARG1 R1
#define RARG2 R2
#define FARG R3

// func runtime·domsanread(addr unsafe.Pointer, sz uintptr)
// Called from msanread.
TEXT	runtime·domsanread(SB), NOSPLIT, $0-16
	MOVD	addr+0(FP), RARG0
	MOVD	sz+8(FP), RARG1
	// void __msan_read_go(void *addr, uintptr_t sz);
	MOVD	$__msan_read_go(SB), FARG
	JMP	msancall<>(SB)

//go:build msan

#include "go_asm.h"
#include "textflag.h"

#define RARG0 R4
#define RARG1 R5
#define RARG2 R6
#define FARG  R7

// func runtime·domsanread(addr unsafe.Pointer, sz uintptr)
// Called from msanread.
TEXT	runtime·domsanread(SB), NOSPLIT, $0-16
	MOVV	addr+0(FP), RARG0
	MOVV	sz+8(FP), RARG1
	// void __msan_read_go(void *addr, uintptr_t sz);
	MOVV	$__msan_read_go(SB), FARG
	JMP	msancall<>(SB)

#define RARG1 DX
#define RARG2 R8
#define RARG3 R9
#else
#define RARG0 DI
#define RARG1 SI
#define RARG2 DX
#define RARG3 CX
#endif

// func runtime·domsanread(addr unsafe.Pointer, sz uintptr)
// Called from msanread.
TEXT	runtime·domsanread(SB), NOSPLIT, $0-16
	MOVQ	addr+0(FP), RARG0
	MOVQ	sz+8(FP), RARG1
	// void __msan_read_go(void *addr, uintptr_t sz);
	MOVQ	$__msan_read_go(SB), AX
	JMP	msancall<>(SB)

			// fall back to making the syscall directly.
			sysSigaction(sig, new, old)
		}
	}

	if msanenabled && old != nil {
		msanread(unsafe.Pointer(old), unsafe.Sizeof(*old))
	}
	if asanenabled && old != nil {
		asanread(unsafe.Pointer(old), unsafe.Sizeof(*old))
	}
}

// callCgoSigaction calls the sigaction function in the runtime/cgo package