| Message ID | 20161018145620.20658-2-bobby.prani@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 18/10/2016 16:56, Pranith Kumar wrote: > gcc does not warn about the wrong type since it is a void pointer > which can be cast to any type. > > Signed-off-by: Pranith Kumar <bobby.prani@gmail.com> > --- > translate-all.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/translate-all.c b/translate-all.c > index 8ca393c..c77470a 100644 > --- a/translate-all.c > +++ b/translate-all.c > @@ -412,7 +412,7 @@ static PageDesc *page_find_alloc(tb_page_addr_t index, int alloc) > > /* Level 2..N-1. */ > for (i = V_L1_SHIFT / V_L2_BITS - 1; i > 0; i--) { > - void **p = atomic_rcu_read(lp); > + void *p = atomic_rcu_read(lp); Wrong; you can see below that p is initialized with p = g_new0(void *, V_L2_SIZE); so it must be a pointer to "void *". You are introducing exactly the bug that is mentioned in the commit message, and it would have screwed up this statement: lp = p + ((index >> (i * V_L2_BITS)) & (V_L2_SIZE - 1)); because it would then omit the multiplication of the RHS by sizeof(void *). How did you test the patch? Coverity would have caught this, but please be more careful. Thanks, Paolo > if (p == NULL) { > if (!alloc) { >
diff --git a/translate-all.c b/translate-all.c index 8ca393c..c77470a 100644 --- a/translate-all.c +++ b/translate-all.c @@ -412,7 +412,7 @@ static PageDesc *page_find_alloc(tb_page_addr_t index, int alloc) /* Level 2..N-1. */ for (i = V_L1_SHIFT / V_L2_BITS - 1; i > 0; i--) { - void **p = atomic_rcu_read(lp); + void *p = atomic_rcu_read(lp); if (p == NULL) { if (!alloc) {
gcc does not warn about the wrong type since it is a void pointer which can be cast to any type. Signed-off-by: Pranith Kumar <bobby.prani@gmail.com> --- translate-all.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)