target/loongarch: fix bad shift in check_ps()

In expression 1ULL << tlb_ps, left shifting by more than 63 bits has
undefined behavior. The shift amount, tlb_ps, is as much as 64. check
"tlb_ps >=64" to fix.

Resolves: Coverity CID 1593475

Fixes: d882c28 ("target/loongarch: check tlb_ps")
Suggested-by: Peter Maydell <[email protected]>
Signed-off-by: Song Gao <[email protected]>
Reviewed-by: Bibo Mao <[email protected]>
Signed-off-by: Bibo Mao <[email protected]>

Author: gaosong-loongson

target/loongarch/internals.h

@@ -43,7 +43,7 @@ enum {
     TLBRET_PE = 7,
 };
 
-bool check_ps(CPULoongArchState *ent, int ps);
+bool check_ps(CPULoongArchState *ent, uint8_t ps);
 
 extern const VMStateDescription vmstate_loongarch_cpu;
 

target/loongarch/tcg/csr_helper.c

@@ -115,7 +115,7 @@ target_ulong helper_csrwr_ticlr(CPULoongArchState *env, target_ulong val)
 
 target_ulong helper_csrwr_pwcl(CPULoongArchState *env, target_ulong val)
 {
-    int shift, ptbase;
+    uint8_t shift, ptbase;
     int64_t old_v = env->CSR_PWCL;
 
     /*

target/loongarch/tcg/tlb_helper.c

@@ -19,12 +19,12 @@
 #include "exec/log.h"
 #include "cpu-csr.h"
 
-bool check_ps(CPULoongArchState *env, int tlb_ps)
+bool check_ps(CPULoongArchState *env, uint8_t tlb_ps)
 {
-     if (tlb_ps > 64) {
-         return false;
-     }
-     return BIT_ULL(tlb_ps) & (env->CSR_PRCFG2);
+    if (tlb_ps >= 64) {
+        return false;
+    }
+    return BIT_ULL(tlb_ps) & (env->CSR_PRCFG2);
 }
 
 void get_dir_base_width(CPULoongArchState *env, uint64_t *dir_base,