• Michael Ellerman's avatar
    selftests/powerpc: Fixup clobbers for TM tests · a02cbc7f
    Michael Ellerman authored
    Some of our TM (Transactional Memory) tests, list "r1" (the stack
    pointer) as a clobbered register.
    
    GCC >= 9 doesn't accept this, and the build breaks:
    
      ptrace-tm-spd-tar.c: In function 'tm_spd_tar':
      ptrace-tm-spd-tar.c:31:2: error: listing the stack pointer register 'r1' in a clobber list is deprecated [-Werror=deprecated]
         31 |  asm __volatile__(
            |  ^~~
      ptrace-tm-spd-tar.c:31:2: note: the value of the stack pointer after an 'asm' statement must be the same as it was before the statement
    
    We do have some fairly large inline asm blocks in these tests, and
    some of them do change the value of r1. However they should all return
    to C with the value in r1 restored, so I think it's legitimate to say
    r1 is not clobbered.
    
    As Segher points out, the r1 clobbers may have been added because of
    the use of `or 1,1,1`, however that doesn't actually clobber r1.
    
    Segher also points out that some of these tests do clobber LR, because
    they call functions, and that is not listed in the clobbers, so add
    that where appropriate.
    Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
    Link: https://lore.kernel.org/r/20191029095324.14669-1-mpe@ellerman.id.au
    a02cbc7f
ptrace-tm-spd-vsx.c 3.31 KB