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| author | Matthew Dempsky <mdempsky@google.com> | 2019-10-17 12:06:53 -0700 |
|---|---|---|
| committer | Matthew Dempsky <mdempsky@google.com> | 2019-10-17 19:29:20 +0000 |
| commit | dc72a2f95feebcfe5ccbd50636b8f8db05587d5f (patch) | |
| tree | 20de26bab1c41d7934bd7cfba5cfbb2efb79c841 /src/runtime/checkptr.go | |
| parent | 4edd78d9f8322f3627dbdc83775bf2134502a1ef (diff) | |
| download | go-dc72a2f95feebcfe5ccbd50636b8f8db05587d5f.tar.gz go-dc72a2f95feebcfe5ccbd50636b8f8db05587d5f.zip | |
cmd/compile: detect unsafe conversions from smaller to larger types
This CL extends the runtime instrumentation for (*T)(ptr) to also
check that the first and last bytes of *(*T)(ptr) are part of the same
heap object.
Updates #22218.
Updates #34959.
Change-Id: I2c8063fe1b7fe6e6145e41c5654cb64dd1c9dd41
Reviewed-on: https://go-review.googlesource.com/c/go/+/201778
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Diffstat (limited to 'src/runtime/checkptr.go')
| -rw-r--r-- | src/runtime/checkptr.go | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/src/runtime/checkptr.go b/src/runtime/checkptr.go index 040a19a39c..a6d33c5af1 100644 --- a/src/runtime/checkptr.go +++ b/src/runtime/checkptr.go @@ -7,14 +7,20 @@ package runtime import "unsafe" type ptrAlign struct { - ptr unsafe.Pointer - align uintptr + ptr unsafe.Pointer + elem *_type } func checkptrAlignment(p unsafe.Pointer, elem *_type) { + // Check that (*T)(p) is appropriately aligned. // TODO(mdempsky): What about fieldAlign? if uintptr(p)&(uintptr(elem.align)-1) != 0 { - panic(ptrAlign{p, uintptr(elem.align)}) + panic(ptrAlign{p, elem}) + } + + // Check that (*T)(p) doesn't straddle multiple heap objects. + if elem.size != 1 && checkptrBase(p) != checkptrBase(add(p, elem.size-1)) { + panic(ptrAlign{p, elem}) } } |