• Eric W. Biederman's avatar
    signal: Unify and correct copy_siginfo_to_user32 · ea64d5ac
    Eric W. Biederman authored
    Among the existing architecture specific versions of
    copy_siginfo_to_user32 there are several different implementation
    problems.  Some architectures fail to handle all of the cases in in
    the siginfo union.  Some architectures perform a blind copy of the
    siginfo union when the si_code is negative.  A blind copy suggests the
    data is expected to be in 32bit siginfo format, which means that
    receiving such a signal via signalfd won't work, or that the data is
    in 64bit siginfo and the code is copying nonsense to userspace.
    
    Create a single instance of copy_siginfo_to_user32 that all of the
    architectures can share, and teach it to handle all of the cases in
    the siginfo union correctly, with the assumption that siginfo is
    stored internally to the kernel is 64bit siginfo format.
    
    A special case is made for x86 x32 format.  This is needed as presence
    of both x32 and ia32 on x86_64 results in two different 32bit signal
    formats.  By allowing this small special case there winds up being
    exactly one code base that needs to be maintained between all of the
    architectures.  Vastly increasing the testing base and the chances of
    finding bugs.
    
    As the x86 copy of copy_siginfo_to_user32 the call of the x86
    signal_compat_build_tests were moved into sigaction_compat_abi, so
    that they will keep running.
    Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
    ea64d5ac
compat_signal.c 5.01 KB