[dev.link] cmd/compile, cmd/link: make itab symbols content-addressable
Extend the content-addressable symbol mechanism to itab symbols.
Itab symbols require global uniqueness (as at run time we compare
pointers), so it needs to be reliably deduplicated. Currently the
content hash depends on symbol name expansion, so we can only do
this when all Go packages are built with know package paths. Fall
back to checking names if any Go package is built with unknown
package path.
Change-Id: Icf5e8873755050c20e5fc6549f6de1c883254c89
Reviewed-on: https://go-review.googlesource.com/c/go/+/245719 Reviewed-by: Jeremy Faller <jeremy@golang.org>
[dev.link] cmd/compile, cmd/link: reference type symbol of defined type by index
The type descriptor symbol of a defined (named) type (and pointer
to it) is defined only in the package that defines the type. It
is not dupOK, unlike other type descriptors. So it can be
referenced by index. Currently it is referenced by name for
cross-package references, because the index is not exported and
so not known to the referencing package.
This CL passes the index through the export data, so the symbol
can be referenced by index, and does not need to be looked up by
name. This also makes such symbol references consistent: it is
referenced by index within the defining package and also cross-
package, which makes it easier for content hashing (in later CLs).
One complication is that we need to set flags on referenced
symbols (specifically, the UsedInIface flag). Before, they are
non-package refs, which naturally carry flags in the object file.
For indexed refs, we currently don't put their flags in the
object file. Introduce a new block for this.
Change-Id: I8126f8e318ac4e6609eb2ac136201fd6c264c256
Reviewed-on: https://go-review.googlesource.com/c/go/+/245718 Reviewed-by: Jeremy Faller <jeremy@golang.org>
Jeremy Faller [Tue, 21 Jul 2020 19:53:30 +0000 (15:53 -0400)]
[dev.link] move FuncID creation into the compiler/assembler
Leaving creation of the funcID till the linker requires the linker to
load the function and file names into memory. Moving these into the
compiler/assembler prevents this.
This work is a step towards moving all func metadata into the compiler.
[dev.link] cmd/link: make symbol attribute setting more reliable
For dupOK symbols, their attributes should be OR'd. Most of the
attributes are expected to be set consistently across multiple
definitions, but UsedInIface must be OR'd, and for alignment we
need to pick the largest one. Currently the attributes are not
always OR'd, depending on addSym returning true or false. This
doesn't cause any real problem, but it would be a problem if we
make type descriptor symbols content-addressable.
This CL removes the second result of addSym, and lets preloadSyms
always set the attributes. Also removes the alignment handling on
addSym, handles it in preloadSyms only.
Change-Id: I06b3f0adb733f6681956ea9ef54736baa86ae7bc
Reviewed-on: https://go-review.googlesource.com/c/go/+/245720 Reviewed-by: Jeremy Faller <jeremy@golang.org>
Notably, _Ctype_union_U was declared as a defined type, but uses were
being rewritten into uses of the underlying type, which matched how
_Cfunc_f was declared.
After CL 230037, cgo started consistently rewriting "C.foo" type
expressions as "_Ctype_foo", which caused it to start emitting:
type _Ctype_enum_E uint32
type _Ctype_union_U [8]byte
Of course, this fails to type-check because _Ctype_enum_E and
_Ctype_union_U are defined types.
This CL changes cgo to emit:
type _Ctype_enum_E = uint32
type _Ctype_union_U = [8]byte
// f unchanged since CL 230037
// _Cfunc_f still unchanged
It would probably be better to fix this in (*typeConv).loadType so
that cgo generated code uses the _Ctype_foo aliases too. But as it
wouldn't have any effect on actual compilation, it's not worth the
risk of touching it at this point in the release cycle.
Updates #39537.
Fixes #40494.
Change-Id: I88269660b40aeda80a9a9433777601a781b48ac0
Reviewed-on: https://go-review.googlesource.com/c/go/+/246057 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Michael Anthony Knyszek [Mon, 13 Jul 2020 19:51:50 +0000 (19:51 +0000)]
runtime: validate candidate searchAddr in pageAlloc.find
Currently pageAlloc.find attempts to find a better estimate for the
first free page in the heap, even if the space its looking for isn't
necessarily going to be the first free page in the heap (e.g. if npages
>= 2). However, in doing so it has the potential to return a searchAddr
candidate that doesn't actually correspond to mapped memory, but this
candidate might still be adopted. As a result, pageAlloc.alloc's fast
path may look at unmapped summary memory and segfault. This case is rare
on most operating systems since the heap is kept fairly contiguous, so
the chance that the candidate searchAddr discovered is unmapped is
fairly low. Even so, this is totally possible and outside the user's
control when it happens (in fact, it's likely to happen consistently for
a given user on a given system).
Fix this problem by ensuring that our candidate always points to mapped
memory. We do this by looking at mheap's arenas structure first. If it
turns out our candidate doesn't correspond to mapped memory, then we
look at inUse to round up the searchAddr to the next mapped address.
While we're here, clean up some documentation related to searchAddr.
Fixes #40191.
Change-Id: I759efec78987e4a8fde466ae45aabbaa3d9d4214
Reviewed-on: https://go-review.googlesource.com/c/go/+/242680
Run-TryBot: Michael Knyszek <mknyszek@google.com> Reviewed-by: Austin Clements <austin@google.com> Reviewed-by: Michael Pratt <mpratt@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Jeremy Faller [Tue, 28 Jul 2020 17:49:13 +0000 (13:49 -0400)]
[dev.link] ensure package path is set when TEXT symbols are created
We're reworking pclntab generation in the linker, and with that we're
moving FuncID generation in to the compiler. Determining the FuncID is
done by a lookup on the package.function name; therefore, we need the
package whenever we make the TEXT symbols.
Jeremy Faller [Thu, 16 Jul 2020 20:18:49 +0000 (16:18 -0400)]
[dev.link] create runtime.funcnametab
Move the function names out of runtime.pclntab_old, creating
runtime.funcnametab. There is an unfortunate artifact in this change in
that calculating the funcID still requires loading the name. Future work
will likely pull this out and put it into the object file Funcs.
Jeremy Faller [Wed, 24 Jun 2020 18:30:16 +0000 (14:30 -0400)]
[dev.link] cmd/link: add runtime.pcheader
As of July 2020, a fair amount of the new linker's live memory, and
runtime is spent generating pclntab. In an effort to streamline that
code, this change starts breaking up the generation of runtime.pclntab
into smaller chunks that can run later in a link. These changes are
described in an (as yet not widely distributed) document that lays out
an improved format. Largely the work consists of breaking up
runtime.pclntab into smaller pieces, stopping much of the data
rewriting, and getting runtime.pclntab into a form where we can reason
about its size and look to shrink it. This change is the first part of
that work -- just pulling out the header, and demonstrating where a
majority of that work will be.
[dev.link] cmd/internal/obj: trim trailing zeros for content hashing
The symbol's data in the object file (sym.P) may already not
contain trailing zeros (e,g, for [10]int{1}), but sometimes it
does (e.g. for [10]int{1,0}). The linker can already handle this
case. We just always trim the trailing zeros for content hashing,
so it can deduplicate [10]int{1} and [10]int{1,0}.
Note: in theory we could just trim the zeros in the symbol data
as well. But currently the linker depends on reading symbol data
for certain symbols (e.g. type symbol decoding), and trimming
will complicates things in the linker.
Cholerae Hu [Fri, 24 Jul 2020 03:00:36 +0000 (11:00 +0800)]
cmd/compile: don't addLocalInductiveFacts if there is no direct edge from if block to phi block
Currently in addLocalInductiveFacts, we only check whether
direct edge from if block to phi block exists. If not, the
following logic will treat the phi block as the first successor,
which is wrong.
This patch makes prove pass more conservative, so we disable
some cases in test/prove.go. We will do some optimization in
the following CL and enable these cases then.
Fixes #40367.
Change-Id: I27cf0248f3a82312a6f7dabe11c79a1a34cf5412
Reviewed-on: https://go-review.googlesource.com/c/go/+/244579 Reviewed-by: Zach Jones <zachj1@gmail.com> Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
We have Reloc and Reloc2. Reloc2 is the better approach and most
code uses Reloc2. There are still uses of Reloc. This CL migrates
them to Reloc2, and removes Reloc.
Change-Id: Id5f6a6019e1e044add682d05e70ebb1548ec58d9
Reviewed-on: https://go-review.googlesource.com/c/go/+/245577 Reviewed-by: Jeremy Faller <jeremy@golang.org>
[dev.link] cmd/link: refactor ExtReloc data structures
We used to generate all external relocations in memory, then emit
the relocation records at a later pass. The data structures were
chosen so that it takes as little memory as possible. Now we just
stream out external relocations, and ExtReloc is just a local
variable. Change the data structure to avoid repeated read of
some fields. Also get rid of ExtRelocView, as it is no longer
necessary.
This reverts CL 202578 and CL 230677 which added an optimization
to use KDSA when available on s390x.
Inconsistencies have been found between the two implementations
in their handling of certain edge cases. Since the Go 1.15 release
is extremely soon it seems prudent to remove this optimization
for now and revisit it in a future release.
Fixes #40475.
Change-Id: Ifb2ed9b9e573784df57383671f1c29d8abae90d4
Reviewed-on: https://go-review.googlesource.com/c/go/+/245497
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ruixin(Peter) Bao <ruixin.bao@ibm.com> Reviewed-by: Filippo Valsorda <filippo@golang.org>
Michael Pratt [Mon, 27 Jul 2020 19:04:17 +0000 (15:04 -0400)]
runtime: ensure startm new M is consistently visible to checkdead
If no M is available, startm first grabs an idle P, then drops
sched.lock and calls newm to start a new M to run than P.
Unfortunately, that leaves a window in which a G (e.g., returning from a
syscall) may find no idle P, add to the global runq, and then in stopm
discover that there are no running M's, a condition that should be
impossible with runnable G's.
To avoid this condition, we pre-allocate the new M ID in startm before
dropping sched.lock. This ensures that checkdead will see the M as
running, and since that new M must eventually run the scheduler, it will
handle any pending work as necessary.
Outside of startm, most other calls to newm/allocm don't have a P at
all. The only exception is startTheWorldWithSema, which always has an M
if there is 1 P (i.e., the currently running M), and if there is >1 P
the findrunnable spinning dance ensures the problem never occurs.
This has been tested with strategically placed sleeps in the runtime to
help induce the correct race ordering, but the timing on this is too
narrow for a test that can be checked in.
cmd/link: don't mark shared library symbols reachable unconditionally
During the transitioning period, we mark symbols from Go shared
libraries reachable unconditionally. That might be useful when
there was still a large portion of the linker using sym.Symbols,
and only reachable symbols were converted to sym.Symbols. Marking
them reachable brings them to the dynamic symbol table, even if
they are not needed, increased the binary size unexpectedly.
That time has passed. Now we largely operate on loader symbols,
and it is not needed to mark them reachable anymore.
OutData was used for a symbol to point to its data in the output
buffer, in order to apply relocations. Now we fold relocation
application to Asmb next to symbol data writing. We can just pass
the output data as a local variable.
Linking cmd/compile,
name old time/op new time/op delta
Asmb_GC 19.0ms ±10% 16.6ms ± 9% -12.50% (p=0.032 n=5+5)
name old alloc/op new alloc/op delta
Asmb_GC 3.78MB ± 0% 0.14MB ± 1% -96.41% (p=0.008 n=5+5)
name old live-B new live-B delta
Asmb_GC 27.5M ± 0% 23.9M ± 0% -13.24% (p=0.008 n=5+5)
Change-Id: Id870a10dce2a0a7447a05029c6d0ab39b47d0a12
Reviewed-on: https://go-review.googlesource.com/c/go/+/244017 Reviewed-by: Jeremy Faller <jeremy@golang.org>
[dev.link] cmd/link: stream external relocations on ARM64 and on Darwin
Support streaming external relocations on ARM64. Support
architecture-specific relocations.
Also support streaming external relocations on Darwin. Do it in
the same CL so ARM64's archreloc doesn't need to support both
streaming and non-streaming.
Change-Id: Ia7fee9957892f98c065022c69a51f47402f4d6e2
Reviewed-on: https://go-review.googlesource.com/c/go/+/243644 Reviewed-by: Jeremy Faller <jeremy@golang.org>
For content-addressable symbols, we build its content hash based
on the symbol data and relocations. When the compiler builds the
symbol data, it may not always include the trailing zeros, e.g.
the data of [10]int64{1,2,3} is only the first 24 bytes.
Therefore, we may end up with symbols with the same contents
(thus same hash) but different sizes. This is not actually a hash
collision. In this case, we can deduplicate them and keep the one
with the larger size.
[dev.link] cmd/internal/obj: handle content-addressable symbols with relocations
For content-addressable symbols with relocations, we build a
content hash based on its content and relocations. Depending on
the category of the referenced symbol, we choose different hash
algorithms such that the hash is globally consistent.
For now, we only support content-addressable symbols with
relocations when the current package's import path is known, so
that the symbol names are fully expanded. Otherwise, if the
referenced symbol is a named symbol whose name is not fully
expanded, the hash won't be globally consistent, and can cause
erroneous collisions. This is fine for now, as the deduplication
is just an optimization, not a requirement for correctness (until
we get to type descriptors).
[dev.link] cmd/compile: make read-only static temps content-addressable
For now, we only do this for symbols without relocations.
Mark static temps "local", as they are not referenced across DSO
boundaries. And deduplicating a local symbol and a non-local
symbol can be problematic.
Dmitri Shuralyov [Wed, 1 Jul 2020 16:49:43 +0000 (12:49 -0400)]
go/printer: remove exported StdFormat flag
The StdFormat flag was added as part of CL 231461, where the primary aim
was to fix the bug #37476. It's expected that the existing printer modes
only adjust spacing but do not change any of the code text itself. A new
printing flag served as a way for cmd/gofmt and go/format to delegate
a part of formatting work to the printer—where it's more more convenient
and efficient to perform—while maintaining current low-level printing
behavior of go/printer unmodified.
We already have cmd/gofmt and the go/format API that implement standard
formatting of Go source code, so there isn't a need to expose StdFormat
flag to the world, as it can only cause confusion.
Consider that to format source in canonical gofmt style completely it
may require tasks A, B, C to be done. In one version of Go, the printer
may do both A and B, while cmd/gofmt and go/format will do the remaining
task C. In another version, the printer may take on doing just A, while
cmd/gofmt and go/format will perform B and C. This makes it hard to add
a gofmt-like mode to the printer without compromising on above fluidity.
This change prefers to shift back some complexity to the implementation
of the standard library, allowing us to avoid creating the new exported
printing flag just for the internal needs of gofmt and go/format today.
We may still want to re-think the API and consider if something better
should be added, but unfortunately there isn't time for Go 1.15. We are
not adding new APIs now, so we can defer this decision until Go 1.16 or
later, when there is more time.
compress/flate: fix another deflate Reset inconsistency
While investigating #34121, fixed by CL 193605,
I discovered another case where Reset was not quite
resetting enough.
This specific case is not a problem in Reset itself but
rather that the Huffman bit writer in one code path
is using uninitialized memory left over from a previous
block, making the compression not choose the optimal
compression method.
Klaus Post [Thu, 7 May 2020 12:50:00 +0000 (12:50 +0000)]
compress/flate: fix deflate Reset consistency
Modify the overflow detection logic to shuffle the contents
of the table to a lower offset to avoid leaking the effects
of a previous use of compress.Writer past Reset calls.
Fixes #34121
Change-Id: I9963eadfa5482881e7b7adbad4c2cae146b669ab
GitHub-Last-Rev: 8b35798cdd4d5a901d6422647b12984d7e500ba3
GitHub-Pull-Request: golang/go#34128
Reviewed-on: https://go-review.googlesource.com/c/go/+/193605 Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
[dev.link] cmd/link: stream out external relocations on AMD64 ELF
Currently, when external linking, in relocsym (in asmb pass), we
convert Go relocations to an in-memory representation of external
relocations, and then in asmb2 pass we write them out to the
output file. This is not memory efficient.
This CL makes it not do the conversion but directly stream out
the external relocations based on Go relocations. Currently only
do this on AMD64 ELF systems.
This reduces memory usage, but makes the asmb2 pass a little
slower.
name old alloc/op new alloc/op delta
Asmb_GC 26.0MB ± 0% 4.1MB ± 0% -84.15% (p=0.008 n=5+5)
Asmb2_GC 8.19MB ± 0% 8.18MB ± 0% ~ (p=0.222 n=5+5)
name old live-B new live-B delta
Asmb_GC 49.2M ± 0% 27.4M ± 0% -44.38% (p=0.008 n=5+5)
Asmb2_GC 51.5M ± 0% 29.7M ± 0% -42.33% (p=0.008 n=5+5)
TODO: figure out what is slow. Possible improvements:
- Remove redundant work in relocsym.
- Maybe there is a better representation for external relocations
now.
- Fine-grained parallelism in emitting external relocations.
- The old elfrelocsect only iterates over external relocations,
now we iterate over all relocations. Is it too many?
[dev.link] cmd/internal/goobj2, cmd/link: use short hash function for short symbols
For symbols of size 8 bytes or below, we can map them to 64-bit
hash values using the identity function. There is no need to use
longer and more expensive hash functions.
For them, we introduce another pseudo-package, PkgIdxHashed64. It
is like PkgIdxHashed except that the hash function is different.
Note that the hash value is not affected with trailing zeros,
e.g. "A" and "A\0\0\0" have the same hash value. This allows
deduplicating a few more symbols. When deduplicating them, we
need to keep the longer one.
Change-Id: Iad0c2e9e569b6a59ca6a121fb8c8f0c018c6da03
Reviewed-on: https://go-review.googlesource.com/c/go/+/242362 Reviewed-by: Jeremy Faller <jeremy@golang.org>
[dev.link] cmd/internal/obj: make integer/float constant symbols content-addressable
Fill in the data at compile time, and get rid of the preprocess
function in the linker.
We need to be careful with symbol alignment: data symbols are
generally naturally aligned, except for string symbols which are
not aligned. When deduplicating two symbols with same content but
different alignments, we need to keep the biggest alignment.
This CL introduces content-addressable symbols (a.k.a. hashed
symbols) to object files. Content-addressable symbols are
identified and referenced by their content hashes, instead of by
names.
In the object file, a new pseudo-package index PkgIdxHashed is
introduced, for content-addressable symbols, and a new block is
added to store their hashes. The hashes are used by the linker to
identify and deduplicate the symbols.
For now, we only support content-addressable symbols that are
always locally defined (i.e. no cross-package references).
As a proof of concept, make string constant symbols content-
addressable.
net/http: synchronize "100 Continue" write and Handler writes
The expectContinueReader writes to the connection on the first
Request.Body read. Since a Handler might be doing a read in parallel or
before a write, expectContinueReader needs to synchronize with the
ResponseWriter, and abort if a response already went out.
Filippo Valsorda [Fri, 19 Jun 2020 02:45:52 +0000 (22:45 -0400)]
crypto/x509: respect VerifyOptions.KeyUsages on Windows
When using the platform verifier on Windows (because Roots is nil) we
were always enforcing server auth EKUs if DNSName was set, and none
otherwise. If an application was setting KeyUsages, they were not being
respected.
Started correctly surfacing IncompatibleUsage errors from the system
verifier, as those are the ones applications will see if they are
affected by this change.
Also refactored verify_test.go to make it easier to add tests for this,
and replaced the EKULeaf chain with a new one that doesn't have a SHA-1
signature.
Copy and adapt tests from text/template, to exercise more of html/template's copy.
Various differences in behavior are flagged with NOTE comments or t.Skip
and documented in #40075. Many of them are probably bugs.
One clarifying test case added to both text/template and html/template.
net: hangup TCP connection after Dial timeout in Plan 9
After Dial timeout, force close the TCP connection by writing "hangup"
to the control file. This unblocks the "connect" command if the
connection is taking too long to establish, and frees up the control
file FD.
Fixes #40118
Change-Id: I1cef8539cd9fe0793e32b49c9d0ef636b4b26e1d
Reviewed-on: https://go-review.googlesource.com/c/go/+/241638
Run-TryBot: David du Colombier <0intro@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: David du Colombier <0intro@gmail.com>
Than McIntosh [Wed, 8 Jul 2020 22:32:36 +0000 (18:32 -0400)]
[dev.link] cmd/compile: make compiler-generated ppc64 TOC symbols static
Set the AttrStatic flag on compiler-emitted TOC symbols for ppc64; these
symbols don't need to go into the final symbol table in Go binaries.
This fixes a buglet introduced by CL 240539 that was causing failures
on the aix builder.
Ian Lance Taylor [Mon, 6 Jul 2020 21:23:26 +0000 (14:23 -0700)]
runtime: mark OpenBSD raise function nosplit
It is called by the signal handler before switching to gsignal
(sigtrampgo -> sigfwdgo -> dieFromSignal -> raise)
which means that it must not split the stack.
All other instances of raise are already marked nosplit.
Fixes #40076
Change-Id: I4794491331af48c46d0d8ebc82d34c6483f0e6cd
Reviewed-on: https://go-review.googlesource.com/c/go/+/241121
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: David Chase <drchase@google.com> Reviewed-by: Cherry Zhang <cherryyz@google.com>
Joe Tsai [Wed, 8 Jul 2020 05:18:17 +0000 (22:18 -0700)]
os: fix regression with handling of nil *File
Use of a nil *File as an argument should not result in a panic,
but result in the ErrInvalid error being returned.
Fix the copy_file_range implementation to preserve this semantic.
Fixes #40115
Change-Id: Iad5ac39664a3efb7964cf55685be636940a8db13
Reviewed-on: https://go-review.googlesource.com/c/go/+/241417 Reviewed-by: Ian Lance Taylor <iant@golang.org> Reviewed-by: Damien Neil <dneil@google.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Than McIntosh [Tue, 30 Jun 2020 14:22:13 +0000 (10:22 -0400)]
[dev.link] cmd/link: skip symtab entries for selected file local symbols
Don't emit symbol table entries for compiler-generated file-local
symbols (this category includes .stmp_* temporaries and *.stkobj
symbols). Note that user-written static symbols within assembler
sources will still be added to the symbol table. Apply the same test
when emitting DWARF for global variables.
Than McIntosh [Tue, 30 Jun 2020 11:55:16 +0000 (07:55 -0400)]
[dev.link] cmd/compile: mark stmp and stkobj symbols as static
Mark compiler-generated ".stmp_%d" and "<fn>.stkobj" symbols as
AttrStatic, so as to tell the linker that they do not need to be
inserted into its name lookup tables.
A+C: add Kush Patel (corporate CLA for Hootsuite Inc)
I'm from Hootsuite. We're a Canadian tech company who provides products
and services to businesses, organizations and individuals to really help
them succeed on social. We have leveraged Go in our stack for the past
4+ years. I am super happy to give back to Go on behalf of Hootsuite
through a small contribution to pkgsite (with a few more in the works).
We love this project and we love open source :)
Hopefully we can give back more in the future!
Kush
Change-Id: Id534a41d78e17e1fa48a8ddecd1ca110cf812388
GitHub-Last-Rev: 297b8b06e75c3ce485f62677ce4591c5cabe8008
GitHub-Pull-Request: golang/go#40088
Reviewed-on: https://go-review.googlesource.com/c/go/+/241218 Reviewed-by: Julie Qiu <julie@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
net: correct address when listening on IPv4zero tcp4/udp4 on Plan 9
Since Plan 9 doesn't allow us to listen on 0.0.0.0, the Listener
address that's read in from /net is the IPv6 address ::. Convert
this address to 0.0.0.0 when the network is tcp4 or udp4.
Fixes #40045
Change-Id: Icfb69b823e5b80603742d23c3762a812996fe43f
Reviewed-on: https://go-review.googlesource.com/c/go/+/240918
Run-TryBot: David du Colombier <0intro@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: David du Colombier <0intro@gmail.com>
Filippo Valsorda [Tue, 30 Jun 2020 16:04:46 +0000 (12:04 -0400)]
crypto/x509/pkix: print non-standard parsed Names at the end
This doesn't change how ExtraNames are printed, so as not to cause
unnecessary churn of current outputs. Switched the ExtraNames check to a
nil check as we are checking for just-parsed values.
go/build: rewrite TestDependencies to be cleaner, more correct
TestDependencies defines the dependency policy
(what can depend on what) for the standard library.
The standard library has outgrown the idea of writing
the policy as a plain map literal. Also, the checker was
ignoring vendored packages, which makes it miss real
problems.
This commit adds a little language for describing
partial orders and rewrites the policy in that language.
It also changes the checker to look inside vendored
packages and adds those to the policy as well.
This turned up one important problem: net is depending
on fmt, unicode via golang.org/x/net/dns/dnsmessage,
filed as #40070.
This is a test-only change, so it should be appropriate
even for the release freeze, especially since it identified
a real bug.
Change-Id: I9b79f30761f167b8587204c959baa973583e39f2
Reviewed-on: https://go-review.googlesource.com/c/go/+/241078
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Than McIntosh [Mon, 6 Jul 2020 13:38:17 +0000 (09:38 -0400)]
[dev.link] cmd/link: remove some unneeded code from writeBlock()
The loader writeBlock() function has code that tries to skip the
initial portion of the input symbols list depending on the address of
the section being written-- this code is dead (skipping is never
triggered) due to similar skipping in the callers; remove this
preamble.
Change-Id: I9769694a3194faf73ebebbbc10ceba4928c3087c
Reviewed-on: https://go-review.googlesource.com/c/go/+/241067
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Jeremy Faller <jeremy@golang.org>
The errors on these lines are meant to be discarded.
Add a comment to make that extra clear.
Change-Id: I38f72af6dfbb0e86677087baf47780b3cc6e7d40
Reviewed-on: https://go-review.googlesource.com/c/go/+/241083 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Than McIntosh [Wed, 1 Jul 2020 12:45:16 +0000 (08:45 -0400)]
[dev.link] cmd/link: better naming for Loader container/subsym methods, part 2 of 2
Introduce a new loader method "SetCarrierSym", to be used when
establishing container/containee symbol relationships for symbol
bucketing in the symtab phase.
This new method is intended to be employed in situations where you
have a series of related symbols will be represented by a single
carrier symbol as a combined entity. The pattern here is that the
sub-symbols contain content but will be anonymous from a symbol table
perspective; the carrier symbol has no content itself but will appear
in the symbol table. Examples of carrier symbols that follow this
model are "runtime.itablink" and "runtime.typelink".
Than McIntosh [Tue, 30 Jun 2020 15:30:28 +0000 (11:30 -0400)]
[dev.link] cmd/link: better naming for Loader container/subsym methods, part 1 of 2
Introduce a new loader method "AddInteriorSym" to be used when
establishing container/containee symbol relationships for host object
sub-symbols and GOT/dynamic sub-symbols.
Interior symbols are employed in situations where you have a
"container" or "payload" symbol that has content, and then a series of
"interior" sub-symbols that point into a portion of the container
symbol's content. Each interior symbol will typically have a useful
name / size / value, but no content of its own. From a symbol table
perspective the container symbol is anonymous, but the interior
symbols are added to the output symbol table.
[dev.link] cmd/link: write ELF relocations in mmap on all architectures
In CL 240399 we changed to precompute the size for ELF relocation
records and use mmap to write them, but we left architectures
where elfreloc1 write non-fixed number of bytes. This CL handles
those architectures. When a Go relocation will turn into multiple
ELF relocations, in relocsym we account this difference and add
it to the size calculation. So when emitting ELF relocations, we
know the number of ELF relocations to be emitted.
Change-Id: I6732ab674b442f4618405e5412a77f6e4a3315d7
Reviewed-on: https://go-review.googlesource.com/c/go/+/241079 Reviewed-by: Than McIntosh <thanm@google.com> Reviewed-by: Jeremy Faller <jeremy@golang.org>
Cherry Zhang [Fri, 26 Jun 2020 20:35:49 +0000 (16:35 -0400)]
[dev.link] cmd/link: emit ELF relocations in mmap
Currently, ELF relocations are generated sequentially in the heap
and flushed to output file periodically. In fact, in some cases,
the output size of the relocation records can be easily computed,
as a relocation entry has fixed size. We only need to count the
number of relocation records to compute the size.
Once the size is computed, we can mmap the output with the proper
size, and directly write relocation records in the mapped memory.
It also opens the possibility of writing relocations in parallel
(not done in this CL).
Note: on some architectures, a Go relocation may turn into
multiple ELF relocations, which makes size calculation harder.
This CL does not handle those cases, and it still writes
sequentially in the heap there.
Linking cmd/compile with external linking,
name old time/op new time/op delta
Asmb2 190ms ± 2% 141ms ± 4% -25.74% (p=0.000 n=10+10)
name old alloc/op new alloc/op delta
Asmb2_GC 66.8MB ± 0% 8.2MB ± 0% -87.79% (p=0.008 n=5+5)
name old live-B new live-B delta
Asmb2_GC 66.9M ± 0% 55.2M ± 0% -17.58% (p=0.008 n=5+5)
Alberto Donizetti [Sun, 5 Jul 2020 12:25:03 +0000 (14:25 +0200)]
doc/go1.15: fix wording in a few places
Change-Id: I1dc6871bdab7f3048eacd6738fdcfa64b8700c8a
Reviewed-on: https://go-review.googlesource.com/c/go/+/240998 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Daniel [Fri, 3 Jul 2020 03:07:02 +0000 (03:07 +0000)]
crypto/tls: create certs w/o KeyEncipherment KU for non-RSA keys in generate_cert.go
Summary
The crypto/tls/generate_cert.go utility should only set the template
x509.Certificate's KeyUsage field to a value with the
x509.KeyUsageKeyEncipherment bits set when the certificate subject
public key is an RSA public key, not an ECDSA or ED25519 public key.
Background
RFC 5480 describes the usage of ECDSA elliptic curve subject keys with
X.509. Unfortunately while Section 3 "Key Usages Bits" indicates which
key usage bits MAY be used with a certificate that indicates
id-ecPublicKey in the SubjectPublicKeyInfo field it doesn't provide
guidance on which usages should *not* be included (e.g. the
keyEncipherment bit, which is particular to RSA key exchange). The same
problem is present in RFC 8410 Section 5 describing Key Usage Bits for ED25519 elliptic curve subject keys.
There's an update to RFC 5480 in last call stage within the IETF LAMPS
WG, draft-ietf-lamps-5480-ku-clarifications-00. This update is meant
to clarify the allowed Key Usages extension values for certificates with
ECDSA subject public keys by adding:
> If the keyUsage extension is present in a certificate that indicates
> id-ecPublicKey as algorithm of AlgorithmIdentifier [RFC2986] in
> SubjectPublicKeyInfo, then following values MUST NOT be present:
>
> keyEncipherment; and
> dataEncipherment.
I don't believe there is an update for RFC 8410 in the works but I
suspect it will be clarified similarly in the future.
This commit updates generate_cert.go to ensure when the certificate
public key is ECDSA or ED25519 the generated certificate has the
x509.Certificate.KeyUsage field set to a value that doesn't include KUs
specific to RSA. For ECDSA keys this will adhere to the updated RFC 5480
language.
Cherry Zhang [Tue, 30 Jun 2020 20:51:27 +0000 (16:51 -0400)]
cmd/link: skip fallocate test if not supported, and adjust allocation size on darwin
On Linux, the linker uses fallocate to preallocate the output
file storage. The underlying file system may not support
fallocate, causing the test to fail. Skip the test in this case.
On darwin, apparently F_PREALLOCATE allocates from the end of the
allocation instead of the logical end of the file. Adjust the
size calculation.