s390/smp: make absolute lowcore / cpu restart parameter accesses more robust

[deliverable/linux.git] / arch / s390 / kernel / smp.c

diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index e01408429ad6ab60101c8ed298bd7a0716b56cb9..dc602a61233f8227979287a64ca2d89fc1ce2ebe 100644 (file)
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -273,26 +273,24 @@ static void pcpu_delegate(struct pcpu *pcpu, void (*func)(void *),
                          void *data, unsigned long stack)
 {
        struct _lowcore *lc = lowcore_ptr[pcpu - pcpu_devices];
-       struct {
-               unsigned long   stack;
-               void            *func;
-               void            *data;
-               unsigned long   source;
-       } restart = { stack, func, data, stap() };
+       unsigned long source_cpu = stap();
 
        __load_psw_mask(psw_kernel_bits);
-       if (pcpu->address == restart.source)
+       if (pcpu->address == source_cpu)
                func(data);     /* should not return */
        /* Stop target cpu (if func returns this stops the current cpu). */
        pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
        /* Restart func on the target cpu and stop the current cpu. */
-       memcpy_absolute(&lc->restart_stack, &restart, sizeof(restart));
+       mem_assign_absolute(lc->restart_stack, stack);
+       mem_assign_absolute(lc->restart_fn, (unsigned long) func);
+       mem_assign_absolute(lc->restart_data, (unsigned long) data);
+       mem_assign_absolute(lc->restart_source, source_cpu);
        asm volatile(
                "0:     sigp    0,%0,%2 # sigp restart to target cpu\n"
                "       brc     2,0b    # busy, try again\n"
                "1:     sigp    0,%1,%3 # sigp stop to current cpu\n"
                "       brc     2,1b    # busy, try again\n"
-               : : "d" (pcpu->address), "d" (restart.source),
+               : : "d" (pcpu->address), "d" (source_cpu),
                    "K" (SIGP_RESTART), "K" (SIGP_STOP)
                : "0", "1", "cc");
        for (;;) ;