runtime: use 1-byte load for address checking in racecallatomic
In racecallatomic, we do a load before calling into TSAN, so if
the address is invalid we fault on the Go stack. We currently use
a 8-byte load instruction, regardless of the data size that the
atomic operation is performed on. So if, say, we are doing a
LoadUint32 at an address that is the last 4 bytes of a memory
mapping, we may fault unexpectedly. Do a 1-byte load instead.
(Ideally we should do a load with the right size, so we fault
correctly if we're given an unaligned address for a wide load
across a page boundary. Leave that for another CL.)
Fix AMD64, ARM64, and PPC64. The code already uses 1-byte load
on S390X.
Should fix #60825.
Change-Id: I3dee93eb08ba180c85e86a9d2e71b5b520e8dcf0
Reviewed-on: https://go-review.googlesource.com/c/go/+/503937
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Than McIntosh <thanm@google.com> Reviewed-by: David Chase <drchase@google.com>