Commit graph

2 commits

Author SHA1 Message Date
Cuong Manh Le 0f8dffd0aa all: use ":" for compiler generated symbols
As it can't appear in user package paths.

There is a hack for handling "go:buildid" and "type:*" on windows/386.

Previously, windows/386 requires underscore prefix on external symbols,
but that's only applied for SHOSTOBJ/SUNDEFEXT or cgo export symbols.
"go.buildid" is STEXT, "type.*" is STYPE, thus they are not prefixed
with underscore.

In external linking mode, the external linker can't resolve them as
external symbols. But we are lucky that they have "." in their name,
so the external linker see them as Forwarder RVA exports. See:

 - https://docs.microsoft.com/en-us/windows/win32/debug/pe-format#export-address-table
 - https://sourceware.org/git/?p=binutils-gdb.git;a=blob;f=ld/pe-dll.c;h=e7b82ba6ffadf74dc1b9ee71dc13d48336941e51;hb=HEAD#l972)

This CL changes "." to ":" in symbols name, so theses symbols can not be
found by external linker anymore. So a hacky way is adding the
underscore prefix for these 2 symbols. I don't have enough knowledge to
verify whether adding the underscore for all STEXT/STYPE symbols are
fine, even if it could be, that would be done in future CL.

Fixes #37762

Change-Id: I92eaaf24c0820926a36e0530fdb07b07af1fcc35
Reviewed-on: https://go-review.googlesource.com/c/go/+/317917
Reviewed-by: Than McIntosh <thanm@google.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-08-09 11:28:56 +00:00
Keith Randall 2248fc63ab cmd/compile: give every really deep type a unique name
This avoids the security problem in #29312 where two very deep, but
distinct, types are given the same name. They both make it to the
linker which chooses one, and the use of the other is now type unsafe.

Instead, give every very deep type its own name. This errs on the
other side, in that very deep types that should be convertible to each
other might now not be. But at least that's not a security hole.

Update #29312.

Change-Id: Iac0ebe73fdc50594fd6fbf7432eef65f9a053126
Reviewed-on: https://go-review.googlesource.com/c/go/+/213517
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
2020-01-08 18:43:55 +00:00