Instead of allocating a byte slice for every string,
calculated the required size and create
a single slice big enough to hold all of them.
As an added benefit, any error encountered
will now be returned before allocations occur.
os/exec package benchmarks:
name old time/op new time/op delta
ExecEcho-8 2.14ms ± 1% 2.14ms ± 3% ~ (p=0.842 n=10+9)
name old alloc/op new alloc/op delta
ExecEcho-8 6.35kB ± 0% 6.18kB ± 0% -2.65% (p=0.000 n=10+10)
name old allocs/op new allocs/op delta
ExecEcho-8 69.0 ± 0% 36.0 ± 0% -47.83% (p=0.000 n=10+10)
Change-Id: I84118d8473037d873f73903d4e4f6ed14f531ce7
Reviewed-on: https://go-review.googlesource.com/c/164961
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Miscellaneous additional conversions from raw syscalls
to using their libc equivalent.
Update #17490
Change-Id: If9ab22cc1d676c1f20fb161ebf02b0c28f71585d
Reviewed-on: https://go-review.googlesource.com/c/148257
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
AIX and Solaris both requires libc to make any syscalls and their
implementation is really similar.
Therefore, Solaris files reused by AIX have their name changed to *_libc.
exec_libc.go is also adapted to AIX.
Updates: #25893
Change-Id: I50d1d7b964831637013d5e64799187cd9565c42b
Reviewed-on: https://go-review.googlesource.com/c/138719
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The test added for issue #18146 exposed a long-existing bug in the
Solaris port; notably, that syscall.Exec uses RawSyscall -- which is not
actually functional for the Solaris port (intentionally) and only exists
as a placebo to satisfy build requirements.
Call syscall.execve instead for Solaris.
Fixes#20832
Change-Id: I327d863f4bbbbbb6e5ecf66b82152c4030825d09
Reviewed-on: https://go-review.googlesource.com/47032
Run-TryBot: Shawn Walker-Salas <shawn.walker@oracle.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Linux's execve has (at the time of writing, and since v2.6.30) a bug when it ran
concurrently with clone, in that it would fail to set up some datastructures if
the thread count before and after some steps differed. This is described better
and in more detail by Colin King in Launchpad¹ and kernel² bugs. When a program
written in Go runtime.Exec's a setuid binary, this issue may cause the resulting
process to not have the expected uid. This patch works around the issue by using
a mutex to serialize exec and clone.
1. https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1672819
2. https://bugzilla.kernel.org/show_bug.cgi?id=195453Fixes#19546
Change-Id: I126e87d1d9ce3be5ea4ec9c7ffe13f92e087903d
Reviewed-on: https://go-review.googlesource.com/43713
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
If the caller set ups a Credential in os/exec.Command,
os/exec.Command.Start will end up calling setgroups(2), even if no
supplementary groups were given.
Only root can call setgroups(2) on BSD kernels, which causes Start to
fail for non-root users when they try to set uid and gid for the new
process.
We fix by introducing a new field to syscall.Credential named
NoSetGroups, and setgroups(2) is only called if it is false.
We make this field with inverted logic to preserve backward
compatibility.
RELNOTES=yes
Change-Id: I3cff1f21c117a1430834f640ef21fd4e87e06804
Reviewed-on: https://go-review.googlesource.com/36697
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This is a change improving consistency in the source tree.
The pattern foo &= ^bar, was only used six times in src/ directory.
The usage of the supported &^ (bit clear / AND NOT) operator is way more
common, about factor 10x.
Change-Id: If26a2994fd81d23d42189bee00245eb84e672cf3
Reviewed-on: https://go-review.googlesource.com/21224
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The tree's pretty inconsistent about single space vs double space
after a period in documentation. Make it consistently a single space,
per earlier decisions. This means contributors won't be confused by
misleading precedence.
This CL doesn't use go/doc to parse. It only addresses // comments.
It was generated with:
$ perl -i -npe 's,^(\s*// .+[a-z]\.) +([A-Z]),$1 $2,' $(git grep -l -E '^\s*//(.+\.) +([A-Z])')
$ go test go/doc -update
Change-Id: Iccdb99c37c797ef1f804a94b22ba5ee4b500c4f7
Reviewed-on: https://go-review.googlesource.com/20022
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Dave Day <djd@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
