[PATCH v3] examples/vm_power_manager: use safe version of list iterator

[Hunt, David]

On 08/07/2022 09:51, Hamza Khan wrote:
> Currently, when vm_power_manager exits, we are using a LIST_FOREACH
> macro to iterate over VM info structures while freeing them. This
> leads to use-after-free error. To address this, replace all usages of
> LIST_* with TAILQ_* macros, and use the RTE_TAILQ_FOREACH_SAFE macro
> to iterate and delete VM info structures.
>
> * The change is small and doesn’t affect other code
> * Testing was performed on the patch
>
> Fixes: e8ae9b662506 ("examples/vm_power: channel manager and monitor in host")
> Cc: alan.carew at intel.com
> Cc: stable at dpdk.org
>
> Signed-off-by: Hamza Khan <hamza.khan at intel.com>
>
> ---
> V3: Update commit message
> V2: Use RTE_TAILQ_* marcos
> ---
>   examples/vm_power_manager/channel_manager.c | 20 +++++++++++---------
>   1 file changed, 11 insertions(+), 9 deletions(-)
>
> diff --git a/examples/vm_power_manager/channel_manager.c b/examples/vm_power_manager/channel_manager.c
> index 838465ab4b..e82c26ddca 100644
> --- a/examples/vm_power_manager/channel_manager.c
> +++ b/examples/vm_power_manager/channel_manager.c
> @@ -29,6 +29,8 @@
>   #include "channel_monitor.h"
>   #include "power_manager.h"
>   
> +#include "rte_tailq.h"
> +
>   
>   #define RTE_LOGTYPE_CHANNEL_MANAGER RTE_LOGTYPE_USER1
>   
> @@ -58,16 +60,16 @@ struct virtual_machine_info {
>   	virDomainInfo info;
>   	rte_spinlock_t config_spinlock;
>   	int allow_query;
> -	LIST_ENTRY(virtual_machine_info) vms_info;
> +	RTE_TAILQ_ENTRY(virtual_machine_info) vms_info;
>   };
>   
> -LIST_HEAD(, virtual_machine_info) vm_list_head;
> +RTE_TAILQ_HEAD(, virtual_machine_info) vm_list_head;
>   
>   static struct virtual_machine_info *
>   find_domain_by_name(const char *name)
>   {
>   	struct virtual_machine_info *info;
> -	LIST_FOREACH(info, &vm_list_head, vms_info) {
> +	RTE_TAILQ_FOREACH(info, &vm_list_head, vms_info) {
>   		if (!strncmp(info->name, name, CHANNEL_MGR_MAX_NAME_LEN-1))
>   			return info;
>   	}
> @@ -878,7 +880,7 @@ add_vm(const char *vm_name)
>   
>   	new_domain->allow_query = 0;
>   	rte_spinlock_init(&(new_domain->config_spinlock));
> -	LIST_INSERT_HEAD(&vm_list_head, new_domain, vms_info);
> +	TAILQ_INSERT_HEAD(&vm_list_head, new_domain, vms_info);
>   	return 0;
>   }
>   
> @@ -900,7 +902,7 @@ remove_vm(const char *vm_name)
>   		rte_spinlock_unlock(&vm_info->config_spinlock);
>   		return -1;
>   	}
> -	LIST_REMOVE(vm_info, vms_info);
> +	TAILQ_REMOVE(&vm_list_head, vm_info, vms_info);
>   	rte_spinlock_unlock(&vm_info->config_spinlock);
>   	rte_free(vm_info);
>   	return 0;
> @@ -953,7 +955,7 @@ channel_manager_init(const char *path __rte_unused)
>   {
>   	virNodeInfo info;
>   
> -	LIST_INIT(&vm_list_head);
> +	TAILQ_INIT(&vm_list_head);
>   	if (connect_hypervisor(path) < 0) {
>   		global_n_host_cpus = 64;
>   		global_hypervisor_available = 0;
> @@ -1005,9 +1007,9 @@ channel_manager_exit(void)
>   {
>   	unsigned i;
>   	char mask[RTE_MAX_LCORE];
> -	struct virtual_machine_info *vm_info;
> +	struct virtual_machine_info *vm_info, *tmp;
>   
> -	LIST_FOREACH(vm_info, &vm_list_head, vms_info) {
> +	RTE_TAILQ_FOREACH_SAFE(vm_info, &vm_list_head, vms_info, tmp) {
>   
>   		rte_spinlock_lock(&(vm_info->config_spinlock));
>   
> @@ -1022,7 +1024,7 @@ channel_manager_exit(void)
>   		}
>   		rte_spinlock_unlock(&(vm_info->config_spinlock));
>   
> -		LIST_REMOVE(vm_info, vms_info);
> +		TAILQ_REMOVE(&vm_list_head, vm_info, vms_info);
>   		rte_free(vm_info);
>   	}
>   


Acked-by: David Hunt <david.hunt at intel.com>