There are two issues: First, the number of registers that are used has
to be calculated with "(nb + 3) / 4" (i.e. round always up, not down).
Second, the "start <= ra && (start + nr - 32) > ra" condition for the
wrap-around case is wrong: It has to be tested with "||" instead of "&&".
Since we can reuse this check later for the LSWX instruction, let's
place the fixed code into a helper function, too.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
return msr & (1ULL << MSR_SF);
}
+/**
+ * Check whether register rx is in the range between start and
+ * start + nregs (as needed by the LSWX and LSWI instructions)
+ */
+static inline bool lsw_reg_in_range(int start, int nregs, int rx)
+{
+ return (start + nregs <= 32 && rx >= start && rx < start + nregs) ||
+ (start + nregs > 32 && (rx >= start || rx < start + nregs - 32));
+}
+
extern void (*cpu_ppc_hypercall)(PowerPCCPU *);
#include "exec/exec-all.h"
if (nb == 0)
nb = 32;
- nr = nb / 4;
- if (unlikely(((start + nr) > 32 &&
- start <= ra && (start + nr - 32) > ra) ||
- ((start + nr) <= 32 && start <= ra && (start + nr) > ra))) {
+ nr = (nb + 3) / 4;
+ if (unlikely(lsw_reg_in_range(start, nr, ra))) {
gen_inval_exception(ctx, POWERPC_EXCP_INVAL_LSWX);
return;
}