msan.go

Documentation: runtime

     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  //go:build msan
     6  // +build msan
     7  
     8  package runtime
     9  
    10  import (
    11  	"unsafe"
    12  )
    13  
    14  // Public memory sanitizer API.
    15  
    16  func MSanRead(addr unsafe.Pointer, len int) {
    17  	msanread(addr, uintptr(len))
    18  }
    19  
    20  func MSanWrite(addr unsafe.Pointer, len int) {
    21  	msanwrite(addr, uintptr(len))
    22  }
    23  
    24  // Private interface for the runtime.
    25  const msanenabled = true
    26  
    27  // If we are running on the system stack, the C program may have
    28  // marked part of that stack as uninitialized. We don't instrument
    29  // the runtime, but operations like a slice copy can call msanread
    30  // anyhow for values on the stack. Just ignore msanread when running
    31  // on the system stack. The other msan functions are fine.
    32  //
    33  //go:nosplit
    34  func msanread(addr unsafe.Pointer, sz uintptr) {
    35  	g := getg()
    36  	if g == nil || g.m == nil || g == g.m.g0 || g == g.m.gsignal {
    37  		return
    38  	}
    39  	domsanread(addr, sz)
    40  }
    41  
    42  //go:noescape
    43  func domsanread(addr unsafe.Pointer, sz uintptr)
    44  
    45  //go:noescape
    46  func msanwrite(addr unsafe.Pointer, sz uintptr)
    47  
    48  //go:noescape
    49  func msanmalloc(addr unsafe.Pointer, sz uintptr)
    50  
    51  //go:noescape
    52  func msanfree(addr unsafe.Pointer, sz uintptr)
    53  
    54  //go:noescape
    55  func msanmove(dst, src unsafe.Pointer, sz uintptr)
    56  
    57  // These are called from msan_GOARCH.s
    58  //go:cgo_import_static __msan_read_go
    59  //go:cgo_import_static __msan_write_go
    60  //go:cgo_import_static __msan_malloc_go
    61  //go:cgo_import_static __msan_free_go
    62  //go:cgo_import_static __msan_memmove
    63
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