Modules appear in the moduledata linked list in the order they are
loaded by the dynamic loader, with one exception: the
firstmoduledata itself the module that contains the runtime.
This is not always the first module (when using -buildmode=shared,
it is typically libstd.so, the second module).
The order matters for typelinksinit, so we swap the first module
with whatever module contains the main function.
Updates #18729
This fixes the test case extracted with -linkshared, and now
go test -linkshared encoding/...
passes. However the original issue about a plugin failure is not
yet fixed.
Change-Id: I9f399ecc3518e22e6b0a350358e90b0baa44ac96
Reviewed-on: https://go-review.googlesource.com/35644
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This is needed for typical tests with gccgo, as it passes the
LD_LIBRARY_PATH environment variable to the new program.
Change-Id: I9bf4b0dbdff63f5449c7fcb8124eaeab10ed7f34
Reviewed-on: https://go-review.googlesource.com/35481
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
With GCC 7 (not yet released), cgo fails with errors like
./sigaltstack.go:65:8: call of non-function C.restoreSignalStack
I do not know precisely why. Explicitly declaring that there are no
arguments to the static function is a simple fix for the debug info.
Change-Id: Id96e1cb1e55ee37a9f1f5ad243d7ee33e71584ac
Reviewed-on: https://go-review.googlesource.com/35480
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
We already do this for shared libraries. Do it for plugins also.
Suggestions on how to test this would be welcome.
I'd like to get this in for 1.8. It could lead to mysterious
hangs when using plugins.
Fixes#18676
Change-Id: I03209b096149090b9ba171c834c5e59087ed0f92
Reviewed-on: https://go-review.googlesource.com/35117
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
Make sure that the same type and itab generated in two
different plugins are actually the same thing.
See also CL 35115
Change-Id: I0c1ecb039d7e2bf5a601d58dfa162a435ae4ef76
Reviewed-on: https://go-review.googlesource.com/35116
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Make sure that the same type and itab generated in two
different shared library are actually the same thing.
Change-Id: Ica45862d65ff8bc7ad04d59a41f57223f71224cd
Reviewed-on: https://go-review.googlesource.com/35115
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Wait longer in case the system is heavily loaded.
Fixes#18324.
Change-Id: If9a6da1cf32d0321302d244ee24fb3f80e54489d
Reviewed-on: https://go-review.googlesource.com/34653
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
golang.org/issue/17594 was caused by additab being called more than once for
an itab. golang.org/cl/32131 fixed that by making the itabs local symbols,
but that in turn causes golang.org/issue/18252 because now there are now
multiple itab symbols in a process for a given (type,interface) pair and
different code paths can end up referring to different itabs which breaks
lots of reflection stuff. So this makes itabs global again and just takes
care to only call additab once for each itab.
Fixes#18252
Change-Id: I781a193e2f8dd80af145a3a971f6a25537f633ea
Reviewed-on: https://go-review.googlesource.com/34173
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Confirm that a trivial executable can build and execute using
-fsanitize=memory.
Fixes#18335 (by skipping the tests when they don't work).
Change-Id: Icb7a276ba7b57ea3ce31be36f74352cc68dc89d5
Reviewed-on: https://go-review.googlesource.com/34505
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This fixes Linux and the *BSD platforms on 386/amd64.
A few OS/arch combinations were already saving registers and/or doing
something that doesn't clearly resemble the SysV C ABI; those have
been left alone.
Fixes#18328.
Change-Id: I6398f6c71020de108fc8b26ca5946f0ba0258667
Reviewed-on: https://go-review.googlesource.com/34501
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Explicitly filter any C-only cgo functions out of pclntable,
which allows them to be duplicated with the host binary.
Updates #18190.
Change-Id: I50d8706777a6133b3e95f696bc0bc586b84faa9e
Reviewed-on: https://go-review.googlesource.com/34199
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Now that we try to handle qualifiers correctly (as of CL 33325), don't
strip them from a void* pointer. Otherwise we break a case like "const
void**", as the "const" qualifier is dropped and the resulting
"void**" triggers a warning from the C compiler.
Fixes#18298.
Change-Id: If51df1889b0f6a907715298c152e6d4584747acb
Reviewed-on: https://go-review.googlesource.com/34370
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Also, if we changed the gsignal stack to match the stack we are
executing on, restore it when returning from the signal handler, for
safety.
Fixes#18255.
Change-Id: Ic289b36e4e38a56f8a6d4b5d74f68121c242e81a
Reviewed-on: https://go-review.googlesource.com/34239
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
The pclntable contains pointers to functions. If the function symbol
is exported in a plugin, and there is a matching symbol in the host
binary, then the pclntable of a plugin ends up pointing at the
function in the host module.
This doesn't work because the traceback code expects the pointer to
be in the same module space as the PC value.
So don't export functions that might overlap with the host binary.
This way the pointer stays in its module.
Updates #18190
Change-Id: Ifb77605b35fb0a1e7edeecfd22b1e335ed4bb392
Reviewed-on: https://go-review.googlesource.com/34196
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
It is reported as failing for two people (issues #18202 and #18212).
The failure mode is that the system gets overloaded and other programs
fail to run.
Fixes#18202.
Change-Id: I1f1ca1f5d8eed6cc3a9dffac3289851e09fa662b
Reviewed-on: https://go-review.googlesource.com/34017
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
For reasons that I do not know, OpenBSD does not call pthread_create
directly, but instead looks it up in libpthread.so. That means that we
can't use the code used on other systems to retry pthread_create on
EAGAIN, since that code simply calls pthread_create.
This patch copies that code to an OpenBSD-specific version.
Also, check for an EAGAIN failure in the test, as that seems to be the
underlying cause of the test failure on several systems including OpenBSD.
Fixes#18146.
Change-Id: I3bceaa1e03a7eaebc2da19c9cc146b25b59243ef
Reviewed-on: https://go-review.googlesource.com/33905
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This reverts commit d24b57a6a1.
Reason for revert: Further complications arised (issue 18100). We'll try again in Go 1.9.
Change-Id: I5ca93d2643a4be877dd9c2d8df3359718440f02f
Reviewed-on: https://go-review.googlesource.com/33770
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
Run-TryBot: Minux Ma <minux@golang.org>
From the garbage collector's perspective, time can move backwards in
cgocall. However, in the midst of this time warp, the pointer
arguments to cgocall can go from dead back to live. If a stack growth
happens while they're dead and then a GC happens when they become live
again, GC can crash with a bad heap pointer.
Specifically, the sequence that leads to a panic is:
1. cgocall calls entersyscall, which saves the PC and SP of its call
site in cgocall. Call this PC/SP "X". At "X" both pointer arguments
are live.
2. cgocall calls asmcgocall. Call the PC/SP of this call "Y". At "Y"
neither pointer argument is live.
3. asmcgocall calls the C code, which eventually calls back into the
Go code.
4. cgocallbackg remembers the saved PC/SP "X" in some local variables,
calls exitsyscall, and then calls cgocallbackg1.
5. The Go code causes a stack growth. This stack unwind sees PC/SP "Y"
in the cgocall frame. Since the arguments are dead at "Y", they are
not adjusted.
6. The Go code returns to cgocallbackg1, which calls reentersyscall
with the recorded saved PC/SP "X", so "X" gets stashed back into
gp.syscallpc/sp.
7. GC scans the stack. It sees there's a saved syscall PC/SP, so it
starts the traceback at PC/SP "X". At "X" the arguments are considered
live, so it scans them, but since they weren't adjusted, the pointers
are bad, so it panics.
This issue started as of commit ca4089ad, when the compiler stopped
marking arguments as live for the whole function.
Since this is a variable liveness issue, fix it by adding KeepAlive
calls that keep the arguments live across this whole time warp.
The existing issue7978 test has all of the infrastructure for testing
this except that it's currently up to chance whether a stack growth
happens in the callback (it currently only happens on the
linux-amd64-noopt builder, for example). Update this test to force a
stack growth, which causes it to fail reliably without this fix.
Fixes#17785.
Change-Id: If706963819ee7814e6705693247bcb97a6f7adb8
Reviewed-on: https://go-review.googlesource.com/33710
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Use an explicit ./ to make sure we link against the libgo.so we just
built, not some other libgo.so that the compiler or linker may decide to
seek out.
Fixes#17986.
Change-Id: Id23f6c95aa2b52f4f42c1b6dac45482c22b4290d
Reviewed-on: https://go-review.googlesource.com/33413
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Before this CL, Go programs in c-archive or c-shared buildmodes
would not handle SIGPIPE. That leads to surprising behaviour where
writes on a closed pipe or socket would raise SIGPIPE and terminate
the program. This CL changes the Go runtime to handle
SIGPIPE regardless of buildmode. In addition, SIGPIPE from non-Go
code is forwarded.
Fixes#17393
Updates #16760
Change-Id: I155e82020a03a5cdc627a147c27da395662c3fe8
Reviewed-on: https://go-review.googlesource.com/32796
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The top-level qualifiers are unimportant for our purposes. If a C
function is defined as `const int f(const int i)`, the `const`s are
meaningless to C, and we want to avoid using them in the struct we
create where the `const` has a completely different meaning.
This unwinds https://golang.org/cl/33097 with regard to top-level
qualifiers.
Change-Id: I3d66b0eb43b6d9a586d9cdedfae5a2306b46d96c
Reviewed-on: https://go-review.googlesource.com/33325
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
CL 33239 changed the polling loops from using sched_yield to a sleep
for 1/1000 of a second. The loop counters were not updated, so failing
tests now take 100 seconds to complete. Lower the loop counts to 5
seconds instead.
Change-Id: I7c9a343dacc8188603ecf7e58bd00b535cfc87f5
Reviewed-on: https://go-review.googlesource.com/33280
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
To generate the correct section offset the shared code path for
R_CALL, R_PCREL, and R_GOTPCREL on darwin when externally linking
walks up the symbol heirarchy adding the differences. This is fine,
except in the case where we are generating a GOT lookup, because
the topmost symbol is left in r.Xsym instead of the symbol we are
looking up. So all funcsym GOT lookups were looking up the outer
"go.func.*" symbol.
Fix this by separating out the R_GOTPCREL code path.
For #17828 (and may fix it).
Change-Id: I2c9f4d135e77c17270aa064d8c876dc6d485d659
Reviewed-on: https://go-review.googlesource.com/33211
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This ensures that runtime's signal handlers pass through the TSAN and
MSAN libc interceptors and subsequent calls to the intercepted
sigaction function from C will correctly see them.
Fixes#17753.
Change-Id: I9798bb50291a4b8fa20caa39c02a4465ec40bb8d
Reviewed-on: https://go-review.googlesource.com/33142
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
If a C union type (or a C++ class type) can contain a pointer field,
then run the cgo checks on pointers to that type. This will test the
pointer as though it were an unsafe.Pointer, and will crash if it points
to Go memory that contains a pointer.
Fixes#15942.
Change-Id: Ic2d07ed9648d4b27078ae7683e26196bcbc59fc9
Reviewed-on: https://go-review.googlesource.com/33237
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
In plugins and every program that opens a plugin, include a hash of
every imported package.
There are two versions of each hash: one local and one exported.
As the program starts and plugins are loaded, the first exported
symbol for each package becomes the canonical version.
Any subsequent plugin's local package hash symbol has to match the
canonical version.
Fixes#17832
Change-Id: I4e62c8e1729d322e14b1673bada40fa7a74ea8bc
Reviewed-on: https://go-review.googlesource.com/33161
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Apparently when GOMAXPROCS == 1 a simple sched_yield in a tight loop is
not necessarily sufficient to permit a signal handler to run. Instead,
sleep for 1/1000 of a second.
Fixes#16649.
Change-Id: I83910144228556e742b7a92a441732ef61aa49d9
Reviewed-on: https://go-review.googlesource.com/33239
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
The cgo tool used to simply ignore C type qualifiers. To avoid problems
when a C function expected a qualifier that was not present, cgo emitted
a cast to void* around all pointer arguments. Unfortunately, that broke
code that contains both a function declaration and a macro, when the
macro required the argument to have the right type. To fix this problem,
don't ignore qualifiers. They are easy enough to handle for the limited
set of cases that matter for cgo, in which we don't care about array or
function types.
Fixes#17537.
Change-Id: Ie2988d21db6ee016a3e99b07f53cfb0f1243a020
Reviewed-on: https://go-review.googlesource.com/33097
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
The exported symbol for a plugin can be the only reference to a
type in a program. In particular, "var F func()" will have
the type *func(), which is uncommon.
Fixes#17140
Change-Id: Ide2104edbf087565f5377374057ae54e0c00c57e
Reviewed-on: https://go-review.googlesource.com/29692
Run-TryBot: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
In a function argument, we handle a typedef for a pointer specially,
using the pointer type rather than the typedef, to permit the Go calls
to match the laxer type conversions permitted in C. We record the
typedef so that we use that type in the C code, in case it has a special
attribute. However, using the typedef is wrong when using a pointer to a
basic type, because the C code may sometimes use the typedef and
sometimes not, and using the typedef in all cases will cause incorrect
type errors on the Go side. Fortunately we only really need to use the
typedef when pointing to a struct/union/class, and in such a case
confusion is unlikely.
Fixes#17723.
Change-Id: Id2eaeb156faeaf2e8eb9cf0b8f95b44caf8cfbd2
Reviewed-on: https://go-review.googlesource.com/32536
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
A plugin with no exported symbols is still potentially very useful.
Its init functions are called on load, and it so it can have visible
side effects.
Fixes#17681
Change-Id: Icdca31f48e5ab13c99020a2ef724f3de47dcd74b
Reviewed-on: https://go-review.googlesource.com/32437
Run-TryBot: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
sigfwd calls an arbitrary C signal handler function. The System V ABI
for x86_64 (and the most recent revision of the ABI for i386) requires
the stack to be 16-byte aligned.
Fixes: #17641
Change-Id: I77f53d4a8c29c1b0fe8cfbcc8d5381c4e6f75a6b
Reviewed-on: https://go-review.googlesource.com/32107
Run-TryBot: Bryan Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Plumb the import path of a plugin package through to the linker, and
use it as the prefix on the exported symbol names.
Before this we used the basename of the plugin file as the prefix,
which could conflict and result in multiple loaded plugins sharing
symbols that are distinct.
Fixes#17155Fixes#17579
Change-Id: I7ce966ca82d04e8507c0bcb8ea4ad946809b1ef5
Reviewed-on: https://go-review.googlesource.com/32355
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This is convenient for direct use of `go tool cgo`. We can also use it
from the go tool to reduce the length of the file names that cgo
generates.
Update #17070.
Change-Id: I8466a0a2cc68a732d17d07319e303497715bac8c
Reviewed-on: https://go-review.googlesource.com/32354
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Otherwise, the way the ELF dynamic linker works means that you can end up with
the same itab being passed to additab twice, leading to the itab linked list
having a cycle in it. Add a test to additab in runtime to catch this when it
happens, not some arbitrary and surprsing time later.
Fixes#17594
Change-Id: I6c82edcc9ac88ac188d1185370242dc92f46b1ad
Reviewed-on: https://go-review.googlesource.com/32131
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The Dragonfly libc returns a non-zero value for malloc(-1).
Fixes#17585.
Change-Id: Icfe68011ccbc75c676273ee3c3efdf24a520a004
Reviewed-on: https://go-review.googlesource.com/32050
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
With the old code rewriting refs would rewrite the inner arguments
rather than the outer ones, leaving a reference to C.val in the outer
arguments.
Change-Id: I9b91cb4179eccd08500d14c6591bb15acf8673eb
Reviewed-on: https://go-review.googlesource.com/31672
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
The pointer checking code needs to know the exact type of the parameter
expected by the C function, so that it can use a type assertion to
convert the empty interface returned by cgoCheckPointer to the correct
type. Previously this was done by using a type conversion, but that
meant that the code accepted arguments that were convertible to the
parameter type, rather than arguments that were assignable as in a
normal function call. In other words, some code that should not have
passed type checking was accepted.
This CL changes cgo to always use a function literal for pointer
checking. Now the argument is passed to the function literal, which has
the correct argument type, so type checking is performed just as for a
function call as it should be.
Since we now always use a function literal, simplify the checking code
to run as a statement by itself. It now no longer needs to return a
value, and we no longer need a type assertion.
This does have the cost of introducing another function call into any
call to a C function that requires pointer checking, but the cost of the
additional call should be minimal compared to the cost of pointer
checking.
Fixes#16591.
Change-Id: I220165564cf69db9fd5f746532d7f977a5b2c989
Reviewed-on: https://go-review.googlesource.com/31233
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
