Coverity found a DEADCODE issue in rmw_xireg() claiming that we can't
reach 'RISCV_EXCP_VIRT_INSTRUCTION_FAULT' at the 'done' label:
done:
if (ret) {
return (env->virt_enabled && virt) ?
RISCV_EXCP_VIRT_INSTRUCTION_FAULT : RISCV_EXCP_ILLEGAL_INST;
}
return RISCV_EXCP_NONE;
This happens because the 'virt' flag, which is only used by 'done', is
set to 'false' and it will always remain 'false' in any condition where
we'll jump to 'done':
switch (csrno) {
(...)
case CSR_VSIREG:
isel = env->vsiselect;
virt = true;
break;
default:
goto done;
};
'virt = true' will never reach 'done' because we have a if/else-if/else
block right before the label that will always return:
if (xiselect_aia_range(isel)) {
return ...
} else if (...) {
return ...
} else {
return RISCV_EXCP_ILLEGAL_INST;
}
All this means that we can preserve the current logic by reducing the
'done' label to:
done:
if (ret) {
return RISCV_EXCP_ILLEGAL_INST;
}
return RISCV_EXCP_NONE;
The flag 'virt' is now unused. Remove it.
Fix the 'goto done' identation while we're at it.
Resolves: Coverity CID 1590359
Fixes: dc0280723d ("target/riscv: Decouple AIA processing from xiselect and xireg")
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20250121184847.2109128-2-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
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