diff mbox series

[PULL,08/15] target/ppc: Don't initialize some local variables in ppc_radix64_xlate()

Message ID 20200527053809.356168-9-david@gibson.dropbear.id.au
State New, archived
Headers show
Series [PULL,01/15] ppc/pnv: Fix NMI system reset SRR1 value | expand

Commit Message

David Gibson May 27, 2020, 5:38 a.m. UTC
From: Greg Kurz <groug@kaod.org>

It is the job of the ppc_radix64_get_fully_qualified_addr() function
which is called at the beginning of ppc_radix64_xlate() to set both
lpid *and* pid. It doesn't buy us anything to initialize them first.

Worse, a bug in ppc_radix64_get_fully_qualified_addr(), eg. failing to
set either lpid or pid, would be undetectable by static analysis tools
like coverity.

Some recent versions of gcc (eg. gcc-9.3.1-2.fc30) may still think
that lpid or pid is used uninitialized though, so this also adds
default cases in the switch statements to make it clear this cannot
happen.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <158941062048.240484.9693581559252337111.stgit@bahia.lan>
Reviewed-by: C├ędric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 target/ppc/mmu-radix64.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/target/ppc/mmu-radix64.c b/target/ppc/mmu-radix64.c
index c76879f65b..07f956c986 100644
--- a/target/ppc/mmu-radix64.c
+++ b/target/ppc/mmu-radix64.c
@@ -50,6 +50,8 @@  static bool ppc_radix64_get_fully_qualified_addr(const CPUPPCState *env,
             *lpid = 0;
             *pid = 0;
             break;
+        default:
+            g_assert_not_reached();
         }
     } else {  /* !MSR[HV] -> Guest */
         switch (eaddr & R_EADDR_QUADRANT) {
@@ -64,6 +66,8 @@  static bool ppc_radix64_get_fully_qualified_addr(const CPUPPCState *env,
             *lpid = env->spr[SPR_LPIDR];
             *pid = 0; /* pid set to 0 -> addresses guest operating system */
             break;
+        default:
+            g_assert_not_reached();
         }
     }
 
@@ -433,7 +437,7 @@  static int ppc_radix64_xlate(PowerPCCPU *cpu, vaddr eaddr, int rwx,
                              bool cause_excp)
 {
     CPUPPCState *env = &cpu->env;
-    uint64_t lpid = 0, pid = 0;
+    uint64_t lpid, pid;
     ppc_v3_pate_t pate;
     int psize, prot;
     hwaddr g_raddr;