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target/ppc: Don't initialize some local variables in ppc_radix64_xlate() 

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: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This commit is contained in:
Greg Kurz 2020-05-14 00:57:00 +02:00 committed by David Gibson
parent 1830422611
commit 7caee782e9
1 changed files with 5 additions and 1 deletions
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6
target/ppc/mmu-radix64.c
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@ -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;