virtio-mem: Fix the iterator variable in a vmem->rdl_list loop

[PATCH] virtio-mem: Fix the iterator variable in a vmem->rdl_list loop

Posted by Chenyi Qiang 3 years, 1 month ago

It should be the variable rdl2 to revert the already-notified listeners.

Fixes: 2044969f0b ("virtio-mem: Implement RamDiscardManager interface")
Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
---
 hw/virtio/virtio-mem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c
index d96bde1fab..88c9c10318 100644
--- a/hw/virtio/virtio-mem.c
+++ b/hw/virtio/virtio-mem.c
@@ -341,7 +341,7 @@ static int virtio_mem_notify_plug(VirtIOMEM *vmem, uint64_t offset,
     if (ret) {
         /* Notify all already-notified listeners. */
         QLIST_FOREACH(rdl2, &vmem->rdl_list, next) {
-            MemoryRegionSection tmp = *rdl->section;
+            MemoryRegionSection tmp = *rdl2->section;
 
             if (rdl2 == rdl) {
                 break;
-- 
2.17.1

Re: [PATCH] virtio-mem: Fix the iterator variable in a vmem->rdl_list loop

Posted by David Hildenbrand 3 years, 1 month ago

On 28.12.22 10:03, Chenyi Qiang wrote:
> It should be the variable rdl2 to revert the already-notified listeners.
> 
> Fixes: 2044969f0b ("virtio-mem: Implement RamDiscardManager interface")
> Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
> ---
>   hw/virtio/virtio-mem.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c
> index d96bde1fab..88c9c10318 100644
> --- a/hw/virtio/virtio-mem.c
> +++ b/hw/virtio/virtio-mem.c
> @@ -341,7 +341,7 @@ static int virtio_mem_notify_plug(VirtIOMEM *vmem, uint64_t offset,
>       if (ret) {
>           /* Notify all already-notified listeners. */
>           QLIST_FOREACH(rdl2, &vmem->rdl_list, next) {
> -            MemoryRegionSection tmp = *rdl->section;
> +            MemoryRegionSection tmp = *rdl2->section;
>   
>               if (rdl2 == rdl) {
>                   break;

Indeed, most probably we barely hit that error path in practice. Thanks!

I really have to find a way to simulate a sparse bitmap easily, and to 
inject errors to better test these paths.

https://github.com/davidhildenbrand/qemu.git mem-next

-- 
Thanks,

David / dhildenb

Re: [PATCH] virtio-mem: Fix the iterator variable in a vmem->rdl_list loop

Posted by Philippe Mathieu-Daudé 3 years, 1 month ago

On 28/12/22 10:03, Chenyi Qiang wrote:
> It should be the variable rdl2 to revert the already-notified listeners.
> 
> Fixes: 2044969f0b ("virtio-mem: Implement RamDiscardManager interface")
> Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
> ---
>   hw/virtio/virtio-mem.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c
> index d96bde1fab..88c9c10318 100644
> --- a/hw/virtio/virtio-mem.c
> +++ b/hw/virtio/virtio-mem.c
> @@ -341,7 +341,7 @@ static int virtio_mem_notify_plug(VirtIOMEM *vmem, uint64_t offset,
>       if (ret) {
>           /* Notify all already-notified listeners. */
>           QLIST_FOREACH(rdl2, &vmem->rdl_list, next) {
> -            MemoryRegionSection tmp = *rdl->section;
> +            MemoryRegionSection tmp = *rdl2->section;
>   
>               if (rdl2 == rdl) {
>                   break;

Cc: qemu-stable@nongnu.org
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>