diff options
| author | Dave Cheney <dave@cheney.net> | 2014-11-15 09:57:02 +1100 |
|---|---|---|
| committer | Dave Cheney <dave@cheney.net> | 2014-11-15 09:57:02 +1100 |
| commit | 56716547b8e246c1454a169c12ace1bbaf369f6a (patch) | |
| tree | 789a654f98171d6dcf03f2d0e4ab8553f5e96217 /src | |
| parent | 3d1f54193ee76537569dd2ef1222391ac4a643a3 (diff) | |
| download | go-56716547b8e246c1454a169c12ace1bbaf369f6a.tar.gz | |
[dev.cc] runtime: fix bus error accessing auxv random data on arm5
It's rather unsporting of the kernel to give us a pointer to unaligned memory.
This fixes one crash, the next crash occurs in the soft float emulation.
LGTM=minux, rsc, austin
R=minux, rsc, austin
CC=golang-codereviews
https://codereview.appspot.com/177730043
Diffstat (limited to 'src')
| -rw-r--r-- | src/runtime/os_linux_arm.go | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/src/runtime/os_linux_arm.go b/src/runtime/os_linux_arm.go index 9b0ade614..d5b37d6ab 100644 --- a/src/runtime/os_linux_arm.go +++ b/src/runtime/os_linux_arm.go @@ -50,9 +50,12 @@ func setup_auxv(argc int32, argv **byte) { for i := 0; auxv[i] != _AT_NULL; i += 2 { switch auxv[i] { - case _AT_RANDOM: // kernel provided 16-byte worth of random data + case _AT_RANDOM: // kernel provides a pointer to 16-bytes worth of random data if auxv[i+1] != 0 { - randomNumber = *(*uint32)(unsafe.Pointer(uintptr(auxv[i+1]))) + // the pointer provided may not be word alined, so we must to treat it + // as a byte array. + rnd := (*[16]byte)(unsafe.Pointer(uintptr(auxv[i+1]))) + randomNumber = uint32(rnd[0]) | uint32(rnd[1])<<8 | uint32(rnd[2])<<16 | uint32(rnd[3])<<24 } case _AT_PLATFORM: // v5l, v6l, v7l |