There is general agreement that the very short list of things that ISO
C says you can do in an async signal handler should all work when the
handler is running on an alternate signal stack with only MINSIGSTKSZ
space. This patch adds tests to make sure those things do work.
To facilitate this, there is a new set of test support routines for
setting up alternate signal stacks; see support/xsignal.h for the API.
* support/xsignal.h (xalloc_sigstack, xfree_sigstack)
(xget_sigstack_location): New test support functions.
* support/xsigstack.c: New file, implementing them.
* support/tst-xsigstack.c: New test for them.
* support/Makefile: Update.
* signal/tst-minsigstksz-1.c
* signal/tst-minsigstksz-2.c
* signal/tst-minsigstksz-3.c
* signal/tst-minsigstksz-3a.c
* signal/tst-minsigstksz-4.c: New tests.
* signal/Makefile: Run them.
This adds system call wrappers for pkey_alloc, pkey_free, pkey_mprotect,
and x86-64 implementations of pkey_get and pkey_set, which abstract over
the PKRU CPU register and hide the actual number of memory protection
keys supported by the CPU. pkey_mprotect with a -1 key is implemented
using mprotect, so it will work even if the kernel does not support the
pkey_mprotect system call.
The system call wrapers use unsigned int instead of unsigned long for
parameters, so that no special treatment for x32 is needed. The flags
argument is currently unused, and the access rights bit mask is limited
to two bits by the current PKRU register layout anyway.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The new test driver in <support/test-driver.c> has feature parity with
the old one. The main difference is that its hooking mechanism is
based on functions and function pointers instead of macros. This
commit also implements a new environment variable, TEST_COREDUMPS,
which disables the code which disables coredumps (that is, it enables
them if the invocation environment has not disabled them).
<test-skeleton.c> defines wrapper functions so that it is possible to
use existing macros with the new-style hook functionality.
This commit changes only a few test cases to the new test driver, to
make sure that it works as expected.
Zack Weinberg
Joseph Myers
Florian Weimer