ppc_tr_init_disas_context() correctly sets lazy_tlb_flush to true on
certain CPU models.  However, it leaves it uninitialized, instead of
setting it to false on all others.

It wasn't caught before now because we didn't have examples in the tests
that exercised this path.  However it can now be caught using clang's
undefined behaviour sanitizer and the sam460ex board.

Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 target/ppc/translate.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/target/ppc/translate.c b/target/ppc/translate.c
index 218665b408..3457d29f8e 100644
--- a/target/ppc/translate.c
+++ b/target/ppc/translate.c
@@ -7237,10 +7237,9 @@ static int ppc_tr_init_disas_context(DisasContextBase *dcbase,
     ctx->sf_mode = msr_is_64bit(env, env->msr);
     ctx->has_cfar = !!(env->flags & POWERPC_FLAG_CFAR);
 #endif
-    if (env->mmu_model == POWERPC_MMU_32B ||
-        env->mmu_model == POWERPC_MMU_601 ||
-        (env->mmu_model & POWERPC_MMU_64B))
-            ctx->lazy_tlb_flush = true;
+    ctx->lazy_tlb_flush = env->mmu_model == POWERPC_MMU_32B
+        || env->mmu_model == POWERPC_MMU_601
+        || (env->mmu_model & POWERPC_MMU_64B);
 
     ctx->fpu_enabled = !!msr_fp;
     if ((env->flags & POWERPC_FLAG_SPE) && msr_spe)
-- 
2.14.3

On 20.03.2018 03:03, David Gibson wrote:
> ppc_tr_init_disas_context() correctly sets lazy_tlb_flush to true on
> certain CPU models.  However, it leaves it uninitialized, instead of
> setting it to false on all others.
> 
> It wasn't caught before now because we didn't have examples in the tests
> that exercised this path.  However it can now be caught using clang's
> undefined behaviour sanitizer and the sam460ex board.
> 
> Suggested-by: Peter Maydell <peter.maydell@linaro.org>
> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> ---
>  target/ppc/translate.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/target/ppc/translate.c b/target/ppc/translate.c
> index 218665b408..3457d29f8e 100644
> --- a/target/ppc/translate.c
> +++ b/target/ppc/translate.c
> @@ -7237,10 +7237,9 @@ static int ppc_tr_init_disas_context(DisasContextBase *dcbase,
>      ctx->sf_mode = msr_is_64bit(env, env->msr);
>      ctx->has_cfar = !!(env->flags & POWERPC_FLAG_CFAR);
>  #endif
> -    if (env->mmu_model == POWERPC_MMU_32B ||
> -        env->mmu_model == POWERPC_MMU_601 ||
> -        (env->mmu_model & POWERPC_MMU_64B))
> -            ctx->lazy_tlb_flush = true;
> +    ctx->lazy_tlb_flush = env->mmu_model == POWERPC_MMU_32B
> +        || env->mmu_model == POWERPC_MMU_601
> +        || (env->mmu_model & POWERPC_MMU_64B);
>  
>      ctx->fpu_enabled = !!msr_fp;
>      if ((env->flags & POWERPC_FLAG_SPE) && msr_spe)
> 

Reviewed-by: Thomas Huth <thuth@redhat.com>

On Tue, 20 Mar 2018 13:03:45 +1100
David Gibson <david@gibson.dropbear.id.au> wrote:

> ppc_tr_init_disas_context() correctly sets lazy_tlb_flush to true on
> certain CPU models.  However, it leaves it uninitialized, instead of
> setting it to false on all others.
> 
> It wasn't caught before now because we didn't have examples in the tests
> that exercised this path.  However it can now be caught using clang's
> undefined behaviour sanitizer and the sam460ex board.
> 
> Suggested-by: Peter Maydell <peter.maydell@linaro.org>
> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> ---

Reviewed-by: Greg Kurz <groug@kaod.org>

>  target/ppc/translate.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/target/ppc/translate.c b/target/ppc/translate.c
> index 218665b408..3457d29f8e 100644
> --- a/target/ppc/translate.c
> +++ b/target/ppc/translate.c
> @@ -7237,10 +7237,9 @@ static int ppc_tr_init_disas_context(DisasContextBase *dcbase,
>      ctx->sf_mode = msr_is_64bit(env, env->msr);
>      ctx->has_cfar = !!(env->flags & POWERPC_FLAG_CFAR);
>  #endif
> -    if (env->mmu_model == POWERPC_MMU_32B ||
> -        env->mmu_model == POWERPC_MMU_601 ||
> -        (env->mmu_model & POWERPC_MMU_64B))
> -            ctx->lazy_tlb_flush = true;
> +    ctx->lazy_tlb_flush = env->mmu_model == POWERPC_MMU_32B
> +        || env->mmu_model == POWERPC_MMU_601
> +        || (env->mmu_model & POWERPC_MMU_64B);
>  
>      ctx->fpu_enabled = !!msr_fp;
>      if ((env->flags & POWERPC_FLAG_SPE) && msr_spe)