sparc sets the carry bit when a syscall fails. Use this information to
set errno and return -1 as appropriate.
The added test case calls raw_clone() with flags known to be invalid
according to the clone(2) manpage.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
First of all, let's return pid_t, which appears to be the correct type
given that we return PIDs, and it#s what fork() uses too.
Most importantly though, flush out our PID cache, so that the call
becomes compatible with our getpid_cached() logic.
Add a bit of code that tries to get the right parameter order in place
for some of the better known architectures, and skips
restrict_namespaces for other archs.
This also bypasses the test on archs where we don't know the right
order.
In this case I didn't bother with testing the case where no filter is
applied, since that is hopefully just an issue for now, as there's
nothing stopping us from supporting more archs, we just need to know
which order is right.
Fixes: #5241
The current raw_clone function takes two arguments, the cloning flags and
a pointer to the stack for the cloned child. The raw cloning without
passing a "thread main" function does not make sense if a new stack is
specified, as it returns in both the parent and the child, which will fail
in the child as the stack is virgin. All uses of raw_clone indeed pass NULL
for the stack pointer which indicates that both processes should share the
stack address (so you better don't pass CLONE_VM).
This commit refactors the code to not require the caller to pass the stack
address, as NULL is the only sensible option. It also adds the magic code
needed to make raw_clone work on sparc64, which does not return 0 in %o0
for the child, but indicates the child process by setting %o1 to non-zero.
This refactoring is not plain aesthetic, because non-NULL stack addresses
need to get mangled before being passed to the clone syscall (you have to
apply STACK_BIAS), whereas NULL must not be mangled. Implementing the
conditional mangling of the stack address would needlessly complicate the
code.
raw_clone is moved to a separete header, because the burden of including
the assert machinery and sched.h shouldn't be applied to every user of
missing_syscalls.h
