* Allow clone where both the child function and stack are null. It's
obviously wrong to ask to call a function without a stack, but it's not
necessarily wrong to supply no stack if you're also not supplying a
function.
* Reimplement fork in terms of the clone function, rather than using the
clone system call directly.
This is intended as a step towards enabling use of pid namespaces.
Change-Id: I03c89bd1dc540d8b4ed1c8fdf6644290744b9e91
The clone syscall accepts NULL child stacks, interpreting this to mean
the child gets a copy of the parent's stack with copy-on-write
semantics. However clone(2) is explicitly documented to treat this an
an error.
"Fortunately" every architecture's __bionic_clone implementation pushes
something onto the child stack before making the clone syscall. So we
know fixing this won't break legacy apps, because any app that tried
using a NULL child stack would have died with SIGSEGV.
This change fixes the LTP clone04 testcase.
Change-Id: I663b34f34bc8dad2aa405c46e4eed4418cccca0d
Signed-off-by: Greg Hackmann <ghackmann@google.com>
<features.h> is supposed to take user-settable stuff like _GNU_SOURCE
and _BSD_SOURCE and turn them into __USE_GNU and __USE_BSD for use in
the C library headers. Instead, bionic used to unconditionally define
_BSD_SOURCE and _GNU_SOURCE, and then test _GNU_SOURCE in the header
files (which makes no sense whatsoever).
Bug: 14659579
Change-Id: Ice4cf21a364ea2e559071dc8329e995277d5b987
If you make clone, fork, or vfork system calls directly, you're still
on your own, but we now do the right thing for the clone wrapper.
With this implementation, children lose the getpid caching, but we've
no reason to think that that covers any significant use cases.
Bug: 15387103
Change-Id: Icfab6b63c708fea830960742ec92aeba8ce7680d
Also let clone(2) set the TLS for x86.
Also ensure we initialize the TLS before we clone(2) for all architectures.
Change-Id: Ie5fa4466e1c9ee116a281dfedef574c5ba60c0b5
clone(2) is the public symbol.
Also switch a test from __bionic_clone to clone; testing public API
means the test now works on glibc too.
Change-Id: If59def26a00c3afadb8a6cf9442094c35a59ffde
The kernel now maintains the pthread_internal_t::tid field for us,
and __clone was only used in one place so let's inline it so we don't
have to leave such a dangerous function lying around. Also rename
files to match their content and remove some useless #includes.
Change-Id: I24299fb4a940e394de75f864ee36fdabbd9438f9
2013-11-19 14:08:54 -08:00
Renamed from libc/bionic/bionic_clone.c (Browse further)
