POSIX_ARA_MOD_README.txt

The following changes are made to musl libc:

- Replaced some arch specific asm code to generic C Code:
    This is done by defining a new dummy arch called LLVM. (Defined in ./configure line 331)
    Arch specific asm code will then be ignored by the musl Makefile.
    For the code without a generic C Code replacement, a symbolic link is placed
    to redirect to the x86_64 implementation.
    the following symbolic links are required:
        - arch/LLVM         -> arch/x86_64
        - crt/LLVM          -> crt/x86_64
        - src/setjmp/LLVM   -> src/setjmp/x86_64
        - src/thread/LLVM   -> src/thread/x86_64
    (based on the LLVM dummy arch idea in the project: https://github.com/SRI-CSL/musllvm)

- Created a dummy for pthread_attr_setname_np and pthread_attr_getname_np so that these functions are detectable as syscalls.
    See the following files:
        - include/pthread.h (line 240)
        - src/POSIX_ARA_MOD/pthread_attr_setname_np.c

- Removed weak alias  malloc() -> default_malloc()  and replaced it with a simple function that redirects.
    This allows the SVF to detect malloc() as a syscall.
    See src/malloc/lite_malloc.c (line 118)

- sigaction(), nanosleep(), pipe() and pthread_attr_setschedparam(): Allow the detection of inner struct fields.
    It is hard to analyze a struct or array with multiple values as argument in ARA.
    We circumvent this issue with a macro that unpacks the fields.
    The internal name of sigaction() is now ARA_sigaction_syscall_().
    The internal name of nanosleep() is now ARA_nanosleep_syscall_().
    The internal name of pipe() is now ARA_pipe_syscall_().
    The internal name of pthread_attr_setschedparam() is now ARA_pthread_attr_setschedparam_syscall_().
    See the following files:
        - src/POSIX_ARA_MOD/struct_field_detection.c
        [sigaction]
        - include/signal.h (starting at line 220)
        [nanosleep]
        - include/time.h (line 100)
        - src/time/nanosleep.c
        [pipe]
        - include/unistd.h (line 36)
        - src/unistd/pipe.c
        [pthread_attr_setschedparam]
        - include/pthread.h (line 166)
        - src/thread/pthread_attr_setschedparam.c

- Created extra translation units to detect or remove some functions with ARA.
    The following functions are influenced:
        - __syscall0, __syscall1, ..., __syscall6 [arch/LLVM/syscall_arch.h -> src/POSIX_ARA_MOD/syscall_arch.c]
        - __wake, __futexwait [src/internal/pthread_impl.h -> src/POSIX_ARA_MOD/futex.c]
        - do_read [(src/stdlib/wcstod.c and src/stdlib/wcstol.c) -> src/POSIX_ARA_MOD/do_read.c]

- Removed {sa_handler, sa_sigaction} union in sigaction struct and added the fields in the ordinary way.
    To save a byte in the sigaction struct the sa_handler and sa_sigaction fields are implemented with a union.
    We do not want this because we are analysing the sigaction struct in full.