Ms are allocated via standard heap allocation (`new(m)`), which means we
must keep them alive (i.e., reachable by the GC) until we are completely
done using them.
Ms are primarily reachable through runtime.allm. However, runtime.mexit
drops the M from allm fairly early, long before it is done using the M
structure. If that was the last reference to the M, it is now at risk of
being freed by the GC and used for some other allocation, leading to
memory corruption.
Ms with a Go-allocated stack coincidentally already keep a reference to
the M in sched.freem, so that the stack can be freed lazily. This
reference has the side effect of keeping this Ms reachable. However, Ms
with an OS stack skip this and are at risk of corruption.
Fix this lifetime by extending sched.freem use to all Ms, with the value
of mp.freeWait determining whether the stack needs to be freed or not.
Fixes#56243.
Change-Id: Ic0c01684775f5646970df507111c9abaac0ba52e
Reviewed-on: https://go-review.googlesource.com/c/go/+/443716
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Michael Pratt <mpratt@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
This change moves Linux epoll's syscalls implementation to the
"runtime/internal/syscall" package. The intention in this CL was to
minimise behavioural changes but make the code more generalised. This
also will allow adding new syscalls (like epoll_pwait2) without the
need to implement assembly stubs for each arch.
It also drops epoll_create as not all architectures provide this call.
epoll_create1 was added to the kernel in version 2.6.27 and Go requires
Linux kernel version 2.6.32 or later since Go 1.18. So it is safe to
always use epoll_create1.
This is a resubmit as the previous CL 421994 was reverted due to test
failures after the merge with the master. The issue was fixed in
CL 438615
For #53824
For #51087
Change-Id: I1bd0f23a85b4f9b80178c5dd36fd3e95ff4f9648
Reviewed-on: https://go-review.googlesource.com/c/go/+/440115
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Michael Pratt <mpratt@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
This change moves Linux epoll's syscalls implementation to the
"runtime/internal/syscall" package. The intention in this CL was to
minimise behavioural changes but make the code more generalised. This
also will allow adding new syscalls (like epoll_pwait2) without the
need to implement assembly stubs for each arch.
It also drops epoll_create as not all architectures provide this call.
epoll_create1 was added to the kernel in version 2.6.27 and Go requires
Linux kernel version 2.6.32 or later since Go 1.18. So it is safe to
always use epoll_create1.
For #53824
For #51087
Change-Id: I9a6a26b7f2075a38e041de1bab4691da0ecb94fc
Reviewed-on: https://go-review.googlesource.com/c/go/+/421994
Reviewed-by: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
Auto-Submit: Michael Pratt <mpratt@google.com>
Currently throw() in the signal handler results in "fatal error: unknown
return pc from runtime.sigreturn ...".
Marking sigtramp as TOPFRAME allows gentraceback to stop tracebacks at
the end of a signal handler, since there is not much beyond sigtramp.
This is just done on Linux for now, but may apply to other Unix systems
as well.
Change-Id: I96edcb945283f417a5bfe00ce2fb2b1a0d578692
Reviewed-on: https://go-review.googlesource.com/c/go/+/402190
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
Auto-Submit: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
On Linux, the minimum required kernel version for Go 1.18 was be changed
to 2.6.32, see #45964. The pipe2 syscall was added in 2.6.27.
All other platforms already provide the pipe2 syscall in the minimum
supported version:
- DragonFly BSD added it in version 4.2, see
https://www.dragonflybsd.org/release42/
- FreeBSD added it in version 10.0, see
https://www.freebsd.org/cgi/man.cgi?pipe(2)#end
- NetBSD added it in version 6.0, see
https://man.netbsd.org/pipe2.2#HISTORY
- OpenBSD added it in version 5.7, see
https://man.openbsd.org/pipe.2#HISTORY
- Illumos supports it since 2013, see
https://www.illumos.org/issues/3714
- Solaris supports it since 11.4
This also allows to remove setNonblock which was only used in the pipe
fallback path on these platforms.
Change-Id: I1f40d32fd3065d74e22af77b9ff2292b9cf66706
Reviewed-on: https://go-review.googlesource.com/c/go/+/389354
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
CL 344955 and CL 359476 removed almost all // +build lines, but leaving
some assembly files and generating scripts. Also, some files were added
with // +build lines after CL 359476 was merged. Remove these or rename
files where more appropriate.
For #41184
Change-Id: I7eb85a498ed9788b42a636e775f261d755504ffa
Reviewed-on: https://go-review.googlesource.com/c/go/+/361480
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
m.vdsoSP should be set to the SP of the caller of nanotime1,
instead of the SP of nanotime1 itself, which matches m.vdsoPC.
Otherwise the unmatched vdsoPC and vdsoSP would make the stack
trace look like recursive.
We already do it correctly on AMD64, 386, and RISCV64. This CL
fixes the rest.
Fixes#47324.
Change-Id: I98b6fcfbe9fc6bdd28b8fe2a1299b7c505371dd4
Reviewed-on: https://go-review.googlesource.com/c/go/+/337590
Trust: Cherry Mui <cherryyz@google.com>
Trust: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Don't add them to files in vendor and cmd/vendor though. These will be
pulled in by updating the respective dependencies.
For #41184
Change-Id: Icc57458c9b3033c347124323f33084c85b224c70
Reviewed-on: https://go-review.googlesource.com/c/go/+/319389
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Change-Id: Iec9de5ca56eb68d524bbaa0668515dbd09ad38a1
Reviewed-on: https://go-review.googlesource.com/c/go/+/314770
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Currently, nanotime1 (and walltime1) is not reentrant, in that it
sets m.vdsoSP at entry and clears it at exit. If a signal lands
in between, and nanotime1 is called from the signal handler, it
will clear m.vdsoSP while we are still in nanotime1. If (in the
unlikely event) it is signaled again, m.vdsoSP will be wrong,
which may cause the stack unwinding code to crash.
This CL makes it reentrant, by saving/restoring the previous
vdsoPC and vdsoSP, instead of setting it to 0 at exit.
TODO: have some way to test?
Change-Id: I9ee53b251f1d8a5a489c71d4b4c0df1dee70c3e5
Reviewed-on: https://go-review.googlesource.com/c/go/+/246763
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The callers expect negative errno values, so negate them when necessary.
No test because there is no reasonable way to make pipe/pipe2 fail.
This was reported on a system on which pipe2 returned ENOSYS.
Fixes#37997
Change-Id: I3ad6cbbc2521cf495f8df6ec991a3f781122b508
Reviewed-on: https://go-review.googlesource.com/c/go/+/224592
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Speed up nanotime1 and walltime1 on MIPS64 with vDSO, just like the
other vDSO-enabled targets.
Benchmark numbers on Loongson 3A3000 (GOARCH=mips64le, 1.4GHz) against
current master:
benchmark old ns/op new ns/op delta
BenchmarkNow 868 293 -66.24%
BenchmarkNowUnixNano 851 296 -65.22%
Performance hit on fallback case, tested by using a wrong vDSO symbol name:
benchmark old ns/op new ns/op delta
BenchmarkNow 868 889 +2.42%
BenchmarkNowUnixNano 851 893 +4.94%
Change-Id: Ibfb48893cd060536359863ffee7624c00def646b
GitHub-Last-Rev: 03a58ac2e4
GitHub-Pull-Request: golang/go#35181
Reviewed-on: https://go-review.googlesource.com/c/go/+/203578
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
We'll add a test once all of the POSIX platforms are done.
For #10958, #24543.
Change-Id: If7e3f14e8391791364877629bf415d9f8e788b0a
Reviewed-on: https://go-review.googlesource.com/c/go/+/201401
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
The internal read and write functions used to return -1 on error;
change them to return a negative errno value instead.
This will be used by later CLs in this series.
For most targets this is a simplification, although for ones that call
into libc it is a complication.
Updates #27707
Change-Id: Id02bf9487f03e7e88e4f2b85e899e986738697ad
Reviewed-on: https://go-review.googlesource.com/c/go/+/171823
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
On MIPS, pipe returns two values rather than taking a pointer.
On MIPS64, call pipe2 rather than pipe.
Also, use the correct system call number for fcntl on mips64.
Change-Id: Ie72acdefeb593f44cb98735fc40eac99cf73509e
Reviewed-on: https://go-review.googlesource.com/c/go/+/202417
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This requires defining pipe, pipe2, and setNonblock for various platforms.
The new function is currently only used on AIX. It will be used by
later CLs in this series.
Updates #27707
Change-Id: Id2f987b66b4c66a3ef40c22484ff1d14f58e9b31
Reviewed-on: https://go-review.googlesource.com/c/go/+/171822
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
In preparation for general faketime support, this renames the existing
nanotime, walltime, and write functions to nanotime1, walltime1, and
write1 and wraps them with trivial Go functions. This will let us
inject different implementations on all platforms when faketime is
enabled.
Updates #30439.
Change-Id: Ice5ccc513a32a6d89ea051638676d3ee05b00418
Reviewed-on: https://go-review.googlesource.com/c/go/+/192738
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Working toward making the tree vet-safe instead of having
so many exceptions in cmd/vet/all/whitelist.
This CL makes "GOOS=linux GOARCH=386 go vet -unsafeptr=false runtime" happy,
while keeping "GO_BUILDER_NAME=misc-vetall go tool dist test" happy too.
For #31916.
Change-Id: I3e5586a7ff6e359357350d0602c2259493280ded
Reviewed-on: https://go-review.googlesource.com/c/go/+/176099
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
On Linux, sysUnused currently uses madvise(MADV_DONTNEED) to signal the
kernel that a range of allocated memory contains unneeded data. After a
successful call, the range (but not the data it contained before the
call to madvise) is still available but the first access to that range
will unconditionally incur a page fault (needed to 0-fill the range).
A faster alternative is MADV_FREE, available since Linux 4.5. The
mechanism is very similar, but the page fault will only be incurred if
the kernel, between the call to madvise and the first access, decides to
reuse that memory for something else.
In sysUnused, test whether MADV_FREE is supported and fall back to
MADV_DONTNEED in case it isn't. This requires making the return value of
the madvise syscall available to the caller, so change runtime.madvise
to return it.
Fixes#23687
Change-Id: I962c3429000dd9f4a00846461ad128b71201bb04
Reviewed-on: https://go-review.googlesource.com/135395
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
raise uses tkill to send a signal to the current thread. For this use,
tgkill is functionally equivalent to tkill expect that it also takes the
pid as the first argument.
Using tgkill makes it simpler to run a Go program in a strict sandbox.
With kill and tgkill, the sandbox policy (e.g., seccomp) can prevent the
program from sending signals to other processes by checking that the
first argument == getpid().
With tkill, the policy must whitelist all tids in the process, which is
effectively impossible given Go's dynamic thread creation.
Fixes#27548
Change-Id: I8ed282ef1f7215b02ef46de144493e36454029ea
Reviewed-on: https://go-review.googlesource.com/133975
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The linux syscall functions used in runtime are designed around the calling
convention of returning errors as negative numbers. On some other systems
(like mips and ppc) the actual syscalls signal errors in other ways. This
means that the assembly implementations of the syscall functions on these
platforms need to transform the return values in the error cases to match
the expected negative errno values. This was addressed for certain syscalls
in https://golang.org/cl/19455 and https://golang.org/cl/89235. This patch
handles the rest of the syscall functions in sys_linux_*.s that return any
value for mips/mips64/ppc64.
Fixes#23446
Change-Id: I302100261231f76d5850ab2c2ea080170d7dba72
GitHub-Last-Rev: e358e2b08c
GitHub-Pull-Request: golang/go#26606
Reviewed-on: https://go-review.googlesource.com/125895
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The caller of epollctl expects it to return a negative errno value,
but it returns a positive errno value on mips, mips64 and ppc64.
The change fixes this.
Updates #23446
Change-Id: Ie6372eca6c23de21964caaaa433c9a45ef93531e
Reviewed-on: https://go-review.googlesource.com/89235
Reviewed-by: Carlos Eduardo Seo <cseo@linux.vnet.ibm.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Ever since we added sleep to the runtime back in 2008, we've
implemented it on GNU/Linux with the select (or pselect or pselect6)
system call. But the Linux kernel has a nanosleep system call,
which should be a tiny bit more efficient since it doesn't have to
check to see whether there are any file descriptors. So use it.
Change-Id: Icc3430baca46b082a4d33f97c6c47e25fa91cb9a
Reviewed-on: https://go-review.googlesource.com/108538
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Also fix the indentation of the SYS_* definitions in sys_linux_mipsx.s
and order them numerically.
Change-Id: I0c454301c329a163e7db09dcb25d4e825149858c
Reviewed-on: https://go-review.googlesource.com/98448
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Follow CL 93655 which removed the (commented-out) usage of this
function.
Also remove unused constant _RLIMIT_AS and type rlimit.
Change-Id: Ifb6e6b2104f4c2555269f8ced72bfcae24f5d5e9
Reviewed-on: https://go-review.googlesource.com/94775
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Also order the syscall number list by numerically for mips64x.
Follow-up for CL 92895.
Change-Id: I5f01f8c626132a06160997fce8a2aef0c486bb1c
Reviewed-on: https://go-review.googlesource.com/93616
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This replaces frame size -4/-8 with the NOFRAME flag in mips and
mips64 assembly.
This was automated with:
sed -i -e 's/\(^TEXT.*[A-Z]\),\( *\)\$-[84]/\1|NOFRAME,\2$0/' $(find -name '*_mips*.s')
Plus a manual fix to mkduff.go.
The go binary is identical on both architectures before and after this
change.
Change-Id: I0310384d1a584118c41d1cd3a042bb8ea7227efb
Reviewed-on: https://go-review.googlesource.com/92044
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Currently mmap returns an unsafe.Pointer that encodes OS errors as
values less than 4096. In practice this is okay, but it borders on
being really unsafe: for example, the value has to be checked
immediately after return and if stack copying were ever to observe
such a value, it would panic. It's also not remotely idiomatic.
Fix this by making mmap return a separate pointer value and error,
like a normal Go function.
Updates #22218.
Change-Id: Iefd965095ffc82cc91118872753a5d39d785c3a6
Reviewed-on: https://go-review.googlesource.com/71270
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Currently, threads created by the runtime exist until the whole
program exits. For #14592 and #20395, we want to be able to exit and
clean up threads created by the runtime. This commit implements that
mechanism.
The main difficulty is how to clean up the g0 stack. In cgo mode and
on Solaris and Windows where the OS manages thread stacks, we simply
arrange to return from mstart and let the system clean up the thread.
If the runtime allocated the g0 stack, then we use a new exitThread
syscall wrapper that arranges to clear a flag in the M once the stack
can safely be reaped and call the thread termination syscall.
exitThread is based on the existing exit1 wrapper, which was always
meant to terminate the calling thread. However, exit1 has never been
used since it was introduced 9 years ago, so it was broken on several
platforms. exitThread also has the additional complication of having
to flag that the stack is unused, which requires some tricks on
platforms that use the stack for syscalls.
This still leaves the problem of how to reap the unused g0 stacks. For
this, we move the M from allm to a new freem list as part of the M
exiting. Later, allocm scans the freem list, finds Ms that are marked
as done with their stack, removes these from the list and frees their
g0 stacks. This also allows these Ms to be garbage collected.
This CL does not yet use any of this functionality. Follow-up CLs
will. Likewise, there are no new tests in this CL because we'll need
follow-up functionality to test it.
Change-Id: Ic851ee74227b6d39c6fc1219fc71b45d3004bc63
Reviewed-on: https://go-review.googlesource.com/46037
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
On 32-bit architectures (or if we fail to map a 64-bit-style arena),
we try to map the heap arena just above the end of the process image.
While we can accept any address, using lower addresses is preferable
because lower addresses cause us to map less of the heap bitmap.
However, if a program is linked against C code that has global
constructors, those constructors may call brk/sbrk to allocate memory
(e.g., many C malloc implementations do this for small allocations).
The brk also starts just above the process image, so this may adjust
the brk past the beginning of where we want to put the heap arena. In
this case, the kernel will pick a different address for the arena and
it will usually be very high (at least, as these things go in a 32-bit
address space).
Fix this by consulting the current value of the brk and using this in
addition to the end of the process image to compute the initial arena
placement.
This is implemented only on Linux currently, since we have no evidence
that it's an issue on any other OSes.
Fixes#19831.
Change-Id: Id64b45d08d8c91e4f50d92d0339146250b04f2f8
Reviewed-on: https://go-review.googlesource.com/39810
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Assembly copied from the clock_gettime(CLOCK_MONOTONIC)
call in runtime.nanotime in these files and then modified to use
CLOCK_REALTIME.
Also comment system call numbers in a few other files.
Fixes#11222.
Change-Id: Ie132086de7386f865908183aac2713f90fc73e0d
Reviewed-on: https://go-review.googlesource.com/32177
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Unify the OS-specific versions of msigsave, msigrestore, sigblock,
updatesigmask, and unblocksig into single versions in signal_unix.go.
To do this, make sigprocmask work the same way on all systems, which
required adding a definition of sigprocmask for linux and openbsd.
Also add a single OS-specific function sigmaskToSigset.
Change-Id: I7cbf75131dddb57eeefe648ef845b0791404f785
Reviewed-on: https://go-review.googlesource.com/29689
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
On ARM64, MIPS64, and PPC64, some floating point registers were
reserved for constants 0, 1, 2, 0.5, etc. This CL removes them.
On ARM64, they are never used. On MIPS64 and PPC64, the only use
case is a multiplication-by-2 in the old backend of the compiler,
which is replaced with an addition.
Change-Id: I737cbf43283756e3408964fc88c567a938c57036
Reviewed-on: https://go-review.googlesource.com/28095
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Add missing function prototypes.
Fix function prototypes.
Use FP references instead of SP references.
Fix variable names.
Update comments.
Clean up whitespace. (Not for vet.)
All fairly minor fixes to make vet happy.
Updates #11041
Change-Id: Ifab2cdf235ff61cdc226ab1d84b8467b5ac9446c
Reviewed-on: https://go-review.googlesource.com/27713
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
SB register (R28) is introduced for access external addresses with shorter
instruction sequences. It is loaded at entry points. External data within
2G of SB can be accessed this way.
cmd/internal/obj: relocaltion R_ADDRMIPS is split into two relocations
R_ADDRMIPS and R_ADDRMIPSU, handling the low 16 bits and the "upper" 16
bits of external addresses, respectively, since the instructios may not
be adjacent. It might be better if relocation Variant could be used.
cmd/link/internal/mips64: support new relocations.
cmd/compile/internal/mips64: reserve SB register.
runtime: initialize SB register at entry points.
Change-Id: I5f34868f88c5a9698c042a8a1f12f76806c187b9
Reviewed-on: https://go-review.googlesource.com/19802
Reviewed-by: Minux Ma <minux@golang.org>
The new function runtime.SetCgoTraceback may be used to register stack
traceback and symbolizer functions, written in C, to do a stack
traceback from cgo code.
There is a sample implementation of runtime.SetCgoSymbolizer at
github.com/ianlancetaylor/cgosymbolizer. Just importing that package is
sufficient to get symbolic C backtraces.
Currently only supported on linux/amd64.
Change-Id: If96ee2eb41c6c7379d407b9561b87557bfe47341
Reviewed-on: https://go-review.googlesource.com/17761
Reviewed-by: Austin Clements <austin@google.com>
The caller of mmap expects it to return a positive errno value, but the
linux-arm64 and nacl-386 system calls returned a negative errno value.
Correct them to negate the errno value.
The caller of mincore expects it to return a negative errno value (yes,
this is inconsistent), but the linux-mips64x and linux-ppc64x system
call returned a positive errno value. Correct them to negate the errno
value.
Add a test that mmap returns errno with the correct sign. Brad added a
test for mincore's errno value in https://golang.org/cl/19457.
Fixes#14297.
Change-Id: I2b93f32e679bd1eae1c9aef9ae7bcf0ba39521b5
Reviewed-on: https://go-review.googlesource.com/19455
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Michael Pratt
Andrew Pogrebnoy
Tobias Klauser
Rhys Hiltner
Cherry Mui
Ian Lance Taylor
Meng Zhuo
Wang Xuerui
Austin Clements
Russ Cox
David Wimmer
Wèi Cōngruì
Jason A. Donenfeld
Josh Bleecher Snyder
Cherry Zhang