s390: defective uses of va_arg in __debug_sprintf_event

[Joe Perches]

debug_sprintf_event calls __debug_sprintf_event
with a format and arguments.

There various types of arguments used in these
call, but __debug_sprintf_event uses va_arg
with only long as the type argument so random
errors could occur because the type and argument
are supposed to match.

    debug_entry_t *__debug_sprintf_event(debug_info_t *id, int level, char 
*string, ...)
    {
            [...]
            va_start(ap, string);
            curr_event->string = string;
            for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) 
- 1); idx++)
                    curr_event->args[idx] = va_arg(ap, long);
            va_end(ap);
            [...]
    }

from man va_arg

    va_arg()

    if type is not compatible with the type of the actual next argument
    (as promoted according to the default argument promotions),
    random errors will occur.

For instance, uses like:

arch/s390/kernel/perf_cpum_sf.c:919:    debug_sprintf_event(sfdbg, 6, 
"pmu_enable: es=%i cs=%i ed=%i cd=%i "
arch/s390/kernel/perf_cpum_sf.c-920-                        "tear=%p 
dear=%p\n", cpuhw->lsctl.es, cpuhw->lsctl.cs,
arch/s390/kernel/perf_cpum_sf.c-921-                        cpuhw->lsctl.ed, 
cpuhw->lsctl.cd,
arch/s390/kernel/perf_cpum_sf.c-922-                        (void *) 
cpuhw->lsctl.tear, (void *) cpuhw->lsctl.dear);

where the first 3 arguments are int but their type
as used by va_arg in __debug_sprintf_event is long
which could produce random errors.

Instead of adding complete format % decoding,
perhaps the easiest solution is to change all
the formats to use %lu or %ld and cast each
argument as appropriate.

And I found this when looking at another defect
in debug_sprintf_event where a %p<foo> extension
is unintentionally used via a string concatenation.
as pointed out by Rasmus Villemoes
---
 arch/s390/kernel/perf_cpum_sf.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/s390/kernel/perf_cpum_sf.c b/arch/s390/kernel/perf_cpum_sf.c
index 1c9ddd7aa5ec..1c449a6f841a 100644
--- a/arch/s390/kernel/perf_cpum_sf.c
+++ b/arch/s390/kernel/perf_cpum_sf.c
@@ -212,9 +212,7 @@ static int realloc_sampling_buffer(struct sf_buffer *sfb,
         * the sampling buffer origin.
         */
        if (sfb->sdbt != get_next_sdbt(tail)) {
-               debug_sprintf_event(sfdbg, 3, "realloc_sampling_buffer: "
-                                   "sampling buffer is not linked: origin=%p"
-                                   "tail=%p\n",
+               debug_sprintf_event(sfdbg, 3, "realloc_sampling_buffer: 
sampling buffer is not linked: origin=%p tail=%p\n",
                                    (void *) sfb->sdbt, (void *) tail);
                return -EINVAL;
        }