This is the second of two CLs to roll forward the changes in CL
473495, which was subsequently reverted.
In this patch we move the .dynamic and .got sections from the writable
data segment to the relro segment if the platform supports relro and
we're producing a PIE binary, and also moves .got.plt into relro if
eager binding is in effect (e.g. -bindnow or -Wl,-z,now).
Updates #45681.
Change-Id: I9f4fba6e825b96d1b5e27fb75844450dd0a650b3
Reviewed-on: https://go-review.googlesource.com/c/go/+/571417
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
This CL adds a .xdata section to the PE file generated by the Go linker.
It is also the first CL of the SEH chain that adds effective support
for unwinding the Go stack, as demonstrated by the newly added tests.
The .xdata section is a standard PE section that contains
an array of unwind data info structures. This structures are used to
record the effects a function has on the stack pointer,
and where the nonvolatile registers are saved on the stack [1].
Note that this CL still does not support unwinding the cgo stack.
Updates #57302
[1] https://learn.microsoft.com/en-us/cpp/build/exception-handling-x64#struct-unwind_info
Change-Id: I6f305a51ed130b758ff9ca7b90c091e50a109a6f
Reviewed-on: https://go-review.googlesource.com/c/go/+/457455
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Davis Goodin <dagood@microsoft.com>
Run-TryBot: Quim Muntal <quimmuntal@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
This CL adds a .pdata section to the PE file generated by the Go linker.
The .pdata section is a standard section [1] that contains an array of
function table entries that are used for stack unwinding.
The table entries layout is taken from [2].
This CL just generates the table entries without any unwinding
information, which is enough to start doing some E2E tests
between the Go linker and the Win32 APIs.
The goal of the .pdata table is to allow Windows retrieve
unwind information for a function at a given PC. It does so by doing
a binary search on the table, looking for an entry that meets
BeginAddress >= PC < EndAddress.
Each table entry takes 12 bytes and only non-leaf functions with
frame pointer needs an entry on the .pdata table.
The result is that PE binaries will be ~0.7% bigger due to the unwind
information, a reasonable amount considering the benefits in
debuggability.
Updates #57302
[1] https://learn.microsoft.com/en-us/windows/win32/debug/pe-format#the-pdata-section
[2] https://learn.microsoft.com/en-us/cpp/build/exception-handling-x64#struct-runtime_function
Change-Id: If675d10c64452946dbab76709da20569651e3e9f
Reviewed-on: https://go-review.googlesource.com/c/go/+/461738
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Run-TryBot: Quim Muntal <quimmuntal@gmail.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
This CL updates the Go compiler so it generate SEH unwind info [1] as a
function auxiliary symbol when building for windows/amd64.
A follow up CL will teach the Go linker how to assemble these codes
into the PE .xdata section.
Updates #57302
[1] https://learn.microsoft.com/en-us/cpp/build/exception-handling-x64#struct-unwind_info
Change-Id: I40ae0437bfee326c1a67c2b5e1496f0bf3ecea17
Reviewed-on: https://go-review.googlesource.com/c/go/+/461749
Reviewed-by: Davis Goodin <dagood@microsoft.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Run-TryBot: Quim Muntal <quimmuntal@gmail.com>
Add a new "coverage counter" classification for variables to be used
for storing code coverage counter values (somewhat in the same way
that we identify fuzzer counters). Tagging such variables allows us to
aggregate them in the linker, and to treat updates specially.
Updates #51430.
Change-Id: Ib49fb05736ffece98bcc2f7a7c37e991b7f67bbb
Reviewed-on: https://go-review.googlesource.com/c/go/+/401235
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
By using libFuzzer’s 8-bit counters instead of extra counters, the
coverage instrumentation in libFuzzer mode is improved in three ways:
1- 8-bit counters are supported on all platforms, including macOS and
Windows, with all relevant versions of libFuzzer, whereas extra
counters are a Linux-only feature that only recently received
support on Windows.
2- Newly covered blocks are now properly reported as new coverage by
libFuzzer, not only as new features.
3- The NeverZero strategy is used to ensure that coverage counters
never become 0 again after having been positive once. This resolves
issues encountered when fuzzing loops with iteration counts that
are multiples of 256 (e.g., larger powers of two).
Change-Id: I9021210d7fbffd07c891ad08750402ee91cb3df5
GitHub-Last-Rev: 9057e4b21d
GitHub-Pull-Request: golang/go#51318
Reviewed-on: https://go-review.googlesource.com/c/go/+/387334
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
It is now gone.
Change-Id: I59f68b324af706476695de2f291dd3aa5734e192
Reviewed-on: https://go-review.googlesource.com/c/go/+/351332
Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
The PLT stubs are executable. Put it together with executable
sections, instead of read-only data sections.
Change-Id: I3818414aa0b87c6968c6c7eccce19b0db7c43193
Reviewed-on: https://go-review.googlesource.com/c/go/+/253018
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
This change splits the SDWARFINFO symbol type (a generic container of
DWARF content) into separate sub-classes. The new symbol types are
SDWARFCUINFO comp unit DIE, also CU info and CU packagename syms
SDWARFCONST constant DIE
SDWARFFCN subprogram DIE (default and concrete)
SDWARFABSFCN abstract function DIE
SDWARFTYPE type DIE
SDWARFVAR global variable DIE
Advantage of doing this: in the linker there are several places where
we have to iterate over a symbol's relocations to pick out references
to specific classes of DWARF sub-symbols (for example, looking for all
abstract function DIEs referenced by a subprogram DIE, or looking at
all the type DIEs used in a subprogram DIE). By splitting SDWARFINFO
into parts clients can now look only at the relocation target's sym
type as opposed to having to materialize the target sym name, or do a
lookup.
Change-Id: I4e0ee3216d3c8f1a78bec3d296c01e95b3d025b5
Reviewed-on: https://go-review.googlesource.com/c/go/+/234684
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
This CL adds experimental coverage instrumentation similar to what
github.com/dvyukov/go-fuzz produces in its -libfuzzer mode. The
coverage can be enabled by compiling with -d=libfuzzer. It's intended
to be used in conjunction with -buildmode=c-archive to produce an ELF
archive (.a) file that can be linked with libFuzzer. See #14565 for
example usage.
The coverage generates a unique 8-bit counter for each basic block in
the original source code, and emits an increment operation. These
counters are then collected into the __libfuzzer_extra_counters ELF
section for use by libFuzzer.
Updates #14565.
Change-Id: I239758cc0ceb9ca1220f2d9d3d23b9e761db9bf1
Reviewed-on: https://go-review.googlesource.com/c/go/+/202117
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Allows Go asm calls referencing a function in a .syso file to be
passed through to the external linker, that would have otherwise
raised a "relocation target X not defined" error in cmd/link.
Fixes#33139
Change-Id: I2a8eb6063ebcd05fac96f141acf7652cf9189766
Reviewed-on: https://go-review.googlesource.com/c/go/+/198798
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Fix linking with a package having a .syso file in external link mode,
that would otherwise cause an error before executing the external
linker because it can't find symbols that are exported in the said
.syso file.
Fixes#33139
Change-Id: Id3ee737fba1c6f1e37910593dfedf9c84486d398
Reviewed-on: https://go-review.googlesource.com/c/go/+/186417
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This is broken out from: CL 187117
This new symbol will be populated by the compiler and contain debug line
information that's currently generated in the linker. One might say it's
sad to create a new symbol, but this symbol will replace the isStmt
symbols.
Testing: Ran go build -toolexec 'toolstash -cmp'
Change-Id: If8f7ae4b43b7247076605b6429b7d03a1fd239c5
Reviewed-on: https://go-review.googlesource.com/c/go/+/188238
Reviewed-by: Austin Clements <austin@google.com>
This commit changes the code generated for addressing symbols on AIX
operating system.
On AIX, every symbol accesses must be done via another symbol near the TOC,
named TOC anchor or TOC entry. This TOC anchor is a pointer to the symbol
address.
During Progedit function, when a symbol access is detected, its instructions
are modified to create a load on its TOC anchor and retrieve the symbol.
Change-Id: I00cf8f49c13004bc99fa8af13d549a709320f797
Reviewed-on: https://go-review.googlesource.com/c/151039
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This implements compiler and linker support for separating the
function calling ABI into two ABIs: a stable and an internal ABI. At
the moment, the two ABIs are identical, but we'll be able to evolve
the internal ABI without breaking existing assembly code that depends
on the stable ABI for calling to and from Go.
The Go compiler generates internal ABI symbols for all Go functions.
It uses the symabis information produced by the assembler to create
ABI wrappers whenever it encounters a body-less Go function that's
defined in assembly or a Go function that's referenced from assembly.
Since the two ABIs are currently identical, for the moment this is
implemented using "ABI alias" symbols, which are just forwarding
references to the native ABI symbol for a function. This way there's
no actual code involved in the ABI wrapper, which is good because
we're not deriving any benefit from it right now. Once the ABIs
diverge, we can eliminate ABI aliases.
The linker represents these different ABIs internally as different
versions of the same symbol. This way, the linker keeps us honest,
since every symbol definition and reference also specifies its
version. The linker is responsible for resolving ABI aliases.
Fixes#27539.
Change-Id: I197c52ec9f8fc435db8f7a4259029b20f6d65e95
Reviewed-on: https://go-review.googlesource.com/c/147160
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
This commit adds the new package cmd/link/internal/loadxcoff.
It also adds a new symbol kind in cmd/link/internal/sym package, which
aims to represent TOC entries for XCOFF files.
cmd/dist is updated to add this new package and cmd/internal/xcoff during
the bootstrap.
Updates: #25893
Change-Id: I42b6578cf0ba4cc28ad4aa98122a91ab1d1bbf6e
Reviewed-on: https://go-review.googlesource.com/c/138728
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The tool has gotten better over time, so re-generating the files brings
some advantages like fewer objects, dropping the use of fmt, and
dropping unnecessary bounds checks.
While at it, add the missing go:generate line for obj.AddrType.
Change-Id: I120c9795ee8faddf5961ff0384b9dcaf58d831ff
Reviewed-on: https://go-review.googlesource.com/100015
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
For #22095
Change-Id: I07c288208d94dabae164c2ca0a067402a8e5c2e6
Reviewed-on: https://go-review.googlesource.com/68331
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-10-05 10:50:18 +00:00
Renamed from src/cmd/link/internal/ld/symkind_string.go (Browse further)
