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| 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 | 14d23bfd7bd969901f1912131c2a208d34e4b354 (patch) | |
| tree | 4115bc3a33c8d693172278413428dd8c8301ce15 /src/runtime/os_linux_arm.go | |
| parent | 1f420c13bd693fc94e112927602b75a4da9dbc0f (diff) | |
| download | go-14d23bfd7bd969901f1912131c2a208d34e4b354.tar.gz go-14d23bfd7bd969901f1912131c2a208d34e4b354.zip | |
[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://golang.org/cl/177730043
Diffstat (limited to 'src/runtime/os_linux_arm.go')
| -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 9b0ade6148..d5b37d6ab5 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 |