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>
This subdirectory contains infrastructure which is not put into
installed libraries, but may be linked into programs (installed or
not) and tests.
# Error-checking wrappers
These wrappers test for error return codes an terminate the process on
error. They are declared in these header files:
* support.h
* xsignal.h
* xthread.h
In general, new wrappers should be added to support.h if possible.
However, support.h must remain fully compatible with C90 and therefore
cannot include headers which use identifers not reserved in C90. If
the wrappers need additional types, additional headers such as
signal.h need to be introduced.
# Test framework
The test framework provides a main program for tests, including a
timeout for hanging tests. See README-testing.c for a minimal
example, and test-driver.c for details how to use it. The following
header files provide related declarations:
* check.h
* temp_file.h
* test-driver.h
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