diff mbox series

[2/3] target/ppc/kvm: Replace variable length array in kvmppc_read_hptes()

Message ID 20240221162636.173136-3-thuth@redhat.com
State New
Headers show
Series Replace variable length arrays in ppc KVM code | expand

Commit Message

Thomas Huth Feb. 21, 2024, 4:26 p.m. UTC 
HPTES_PER_GROUP is 8 and HASH_PTE_SIZE_64 is 16, so we don't waste
too many bytes by always allocating the maximum amount of bytes on
the stack here to get rid of the variable length array.

Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 target/ppc/kvm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Peter Maydell Feb. 21, 2024, 4:30 p.m. UTC | #1 
On Wed, 21 Feb 2024 at 16:26, Thomas Huth <thuth@redhat.com> wrote:
>
> HPTES_PER_GROUP is 8 and HASH_PTE_SIZE_64 is 16, so we don't waste
> too many bytes by always allocating the maximum amount of bytes on
> the stack here to get rid of the variable length array.
>
> Suggested-by: Peter Maydell <peter.maydell@linaro.org>
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>  target/ppc/kvm.c | 4 ++--

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM
diff mbox series

Patch

diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
index e7e39c3091..bcf30a5400 100644
--- a/target/ppc/kvm.c
+++ b/target/ppc/kvm.c
@@ -2770,9 +2770,9 @@  void kvmppc_read_hptes(ppc_hash_pte64_t *hptes, hwaddr ptex, int n)
     while (i < n) {
         struct kvm_get_htab_header *hdr;
         int m = n < HPTES_PER_GROUP ? n : HPTES_PER_GROUP;
-        char buf[sizeof(*hdr) + m * HASH_PTE_SIZE_64];
+        char buf[sizeof(*hdr) + HPTES_PER_GROUP * HASH_PTE_SIZE_64];
 
-        rc = read(fd, buf, sizeof(buf));
+        rc = read(fd, buf, sizeof(*hdr) + m * HASH_PTE_SIZE_64);
         if (rc < 0) {
             hw_error("kvmppc_read_hptes: Unable to read HPTEs");
         }