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  1. 20 Nov, 2014 5 commits
  3. 19 Nov, 2014 6 commits
    • Russ Cox's avatar
      runtime: remove assumption that noptrdata data bss noptrbss are ordered and contiguous · 378c2515
      Russ Cox authored 
      The assumption can be violated by external linkers reordering them or
inserting non-Go sections in between them. I looked briefly at trying
to write out the _go_.o in external linking mode in a way that forced
the ordering, but no matter what there's no way to force Go's data
and Go's bss to be next to each other. If there is any data or bss from
non-Go objects, it's very likely to get stuck in between them.

Instead, rewrite the two places we know about that make the assumption.
I grepped for noptrdata to look for more and didn't find any.

The added race test (os/exec in external linking mode) fails without
the changes in the runtime. It crashes with an invalid pointer dereference.

Fixes #9133.

LGTM=dneil
R=dneil
CC=dvyukov, golang-codereviews, iant
https://golang.org/cl/179980043
      378c2515
    • Austin Clements's avatar
      [dev.cc] runtime: add explicit siginfo.si_addr field · f4a52545
      Austin Clements authored 
      struct siginfo_t's si_addr field is part of a union.
Previously, we represented this union in Go using an opaque
byte array and accessed the si_addr field using unsafe (and
wrong on 386 and arm!) pointer arithmetic.  Since si_addr is
the only field we use from this union, this replaces the
opaque byte array with an explicit declaration of the si_addr
field and accesses it directly.

LGTM=minux, rsc
R=rsc, minux
CC=golang-codereviews
https://golang.org/cl/179970044
      f4a52545
    • Austin Clements's avatar
      [dev.cc] runtime: decode power64 branch instructions the way the CPU does · d11a4259
      Austin Clements authored 
      Previously, this used the top 8 bits of an instruction as a
sort-of opcode and ignored the top two bits of the relative
PC.  This worked because these jumps are always negative and
never big enough for the top two bits of the relative PC (also
the bottom 2 bits of the sort-of opcode) to be anything other
than 0b11, but the code is confusing because it doesn't match
the actual structure of the instruction.

Instead, use the real 6 bit opcode and use all 24 bits of
relative PC.

LGTM=rsc
R=rsc, dave
CC=golang-codereviews
https://golang.org/cl/179960043
      d11a4259
    • Russ Cox's avatar
      undo CL 131750044 / 2d6d44ceb80e · 2d53d6b5
      Russ Cox authored 
      Breaks reading from stdin in parent after exec with SysProcAttr{Setpgid: true}.

package main

import (
        "fmt"
        "os"
        "os/exec"
        "syscall"
)

func main() {
        cmd := exec.Command("true")
        cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
        cmd.Run()

        fmt.Printf("Hit enter:")
        os.Stdin.Read(make([]byte, 100))
        fmt.Printf("Bye\n")
}

In go1.3, I type enter at the prompt and the program exits.
With the CL being rolled back, the program wedges at the
prompt.

««« original CL description
syscall: SysProcAttr job control changes

Making the child's process group the foreground process group and
placing the child in a specific process group involves co-ordination
between the parent and child that must be done post-fork but pre-exec.

LGTM=iant
R=golang-codereviews, gobot, iant, mikioh.mikioh
CC=golang-codereviews
https://golang.org/cl/131750044

»»»

LGTM=minux, dneil
R=dneil, minux
CC=golang-codereviews, iant, michael.p.macinnis
https://golang.org/cl/174450043
      2d53d6b5
    • Austin Clements's avatar
      [dev.cc] runtime: allow more address bits in lfstack on Power64 · b76e8360
      Austin Clements authored 
      Previously, lfstack assumed Linux limited user space addresses
to 43 bits on Power64 based on a paper from 2001.  It turns
out the limit is now 46 bits, so lfstack was truncating
pointers.

Raise the limit to 48 bits (for some future proofing and to
make it match amd64) and add a self-test that will fail in a
useful way if ever unpack(pack(x)) != x.

With this change, dev.cc passes all.bash on power64le.

LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/174430043
      b76e8360
    • Alex Brainman's avatar
      [dev.cc] runtime: update sys_windows_386.s and sys_windows_amd64.s for Go conversion · b27c0618
      Alex Brainman authored 
      LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/176970043
      b27c0618
  5. 18 Nov, 2014 11 commits
  7. 17 Nov, 2014 10 commits
  9. 16 Nov, 2014 3 commits
    • David du Colombier's avatar
      [dev.cc] cmd/8g: work around "out of fixed registers" on Plan 9 · 7aa89ea7
      David du Colombier authored 
      This change works around the "out of fixed registers"
issue with the Plan 9 C compiler on 386, introduced by
the Bits change to uint64 in CL 169060043.

The purpose of this CL is to be able to properly
follow the conversion of the Plan 9 runtime to Go
on the Plan 9 builders.

This CL could be reverted once the Go compilers will
be converted to Go.

Thanks to Nick Owens for investigating this issue.

LGTM=rsc
R=rsc
CC=austin, golang-codereviews, mischief
https://golang.org/cl/177860043
      7aa89ea7
    • Russ Cox's avatar
      runtime: fix sudog leak · b3932bab
      Russ Cox authored 
      The SudoG used to sit on the stack, so it was cheap to allocated
and didn't need to be cleaned up when finished.

For the conversion to Go, we had to move sudog off the stack
for a few reasons, so we added a cache of recently used sudogs
to keep allocation cheap. But we didn't add any of the necessary
cleanup before adding a SudoG to the new cache, and so the cached
SudoGs had stale pointers inside them that have caused all sorts
of awful, hard to debug problems.

CL 155760043 made sure SudoG.elem is cleaned up.
CL 150520043 made sure SudoG.selectdone is cleaned up.

This CL makes sure SudoG.next, SudoG.prev, and SudoG.waitlink
are cleaned up. I should have done this when I did the other two
fields; instead I wasted a week tracking down a leak they caused.

A dangling SudoG.waitlink can point into a sudogcache list that
has been "forgotten" in order to let the GC collect it, but that
dangling .waitlink keeps the list from being collected.
And then the list holding the SudoG with the dangling waitlink
can find itself in the same situation, and so on. We end up
with lists of lists of unusable SudoGs that are still linked into
the object graph and never collected (given the right mix of
non-trivial selects and non-channel synchronization).

More details in golang.org/issue/9110.

Fixes #9110.

LGTM=r
R=r
CC=dvyukov, golang-codereviews, iant, khr
https://golang.org/cl/177870043
      b3932bab
    • Russ Cox's avatar
      runtime: update URL for heap dump format · 6150414c
      Russ Cox authored 
      I just created that redirect, so we can change
it once the wiki moves.

LGTM=bradfitz, khr
R=khr, bradfitz
CC=golang-codereviews
https://golang.org/cl/177780043
      6150414c
  11. 15 Nov, 2014 1 commit
  13. 14 Nov, 2014 4 commits