Currently, when register ABI is used, syscall.Syscall calls
entersyscall via a wrapper, so the actual entersyscall records the
caller PC and SP of the wrapper. At the point of the actual
syscall, the wrapper frame is gone, so the recorded PC and SP are
technically invalid. Furthermore, in some functions on some
platforms (e.g. Syscall9 on NetBSD/AMD64), that frame is
overwritten. If we unwind the stack from the recorded syscallpc
and syscallsp, it may go wrong. Fix this by calling the
ABIInternal function directly.
exitsyscall calls are changed as well. It doesn't really matter,
just changed for consistency.
Change-Id: Iead8dd22cf32b05e382414fef664b7c4c1719b7c
Reviewed-on: https://go-review.googlesource.com/c/go/+/376356
Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
This allows the use of CLONE_VFORK and CLONE_VM for fork/exec, preventing
'fork/exec ...: cannot allocate memory' failures from occuring when attempting
to execute commands from a Go process that has a large memory footprint.
Additionally, this should reduce the latency of fork/exec on these platforms.
Fixes#31936
Change-Id: I4e28cf0763173145cacaa5340680dca9ff449305
Reviewed-on: https://go-review.googlesource.com/c/go/+/295849
Trust: Joel Sing <joel@sing.id.au>
Run-TryBot: Joel Sing <joel@sing.id.au>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
This allows the use of CLONE_VFORK and CLONE_VM for fork/exec, preventing
"fork/exec ...: cannot allocate memory" failures from occuring when attempting
to execute commands from a Go process that has a large memory footprint.
Additionally, this should reduce the latency of fork/exec on linux/arm64.
With CLONE_VM the child process shares the same memory with the parent
process. On its own this would lead to conflicting use of the same
memory, so CLONE_VFORK is used to suspend the parent process until the
child releases the memory when switching to the new program binary
via the exec syscall. When the parent process continues to run, one
has to consider the changes to memory that the child process did,
namely the return address of the syscall function needs to be restored
from a register.
exec.Command() callers can start in a faster manner, as child process who
do exec commands job can be cloned faster via vfork than via fork on arm64.
The same problem was addressed on linux/amd64 via issue #5838.
Updates #31936
Contributed by Howard Zhang <howard.zhang@arm.com> and Bin Lu <bin.lu@arm.com>
Change-Id: Ia99d81d877f564ec60d19f17e596276836576eaf
Reviewed-on: https://go-review.googlesource.com/c/go/+/189418
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Add the rawSyscallNoError wrapper function which is used for Linux
syscalls that don't return an error and convert all applicable
occurences of RawSyscall to use it instead.
Fixes#22924
Change-Id: Iff1eddb54573d459faa01471f10398b3d38528dd
Reviewed-on: https://go-review.googlesource.com/84485
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Cherry Mui
Joel Sing
Howard Zhang
Tobias Klauser
Aram Hăvărneanu