Re: [PATCH] semihosting/uaccess.c: Replaced a malloc call with g_malloc.

[Peter Maydell]

On Fri, 28 Jul 2023 at 06:13, dinglimin <dinglimin@cmss.chinamobile.com> wrote:
>
> Replaced a call to malloc() and its respective call to free() with g_malloc() 
> and g_free().
>
> Signed-off-by: dinglimin <dinglimin@cmss.chinamobile.com>
>
> v4 -> V5:Use g_try_malloc() instead of malloc()
> V3 -> V4:Delete null checks after g malloc().
> V2 -> V3:softmmu_unlock_user changes free to g free.
> V1 -> V2:if cpu_memory_rw_debug failed, still need to set p=NULL
>
> Signed-off-by: dinglimin <dinglimin@cmss.chinamobile.com>
> ---
>  semihosting/uaccess.c | 15 +++++++++++----
>  1 file changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/semihosting/uaccess.c b/semihosting/uaccess.c
> index 8018828069..35fdcd69db 100644
> --- a/semihosting/uaccess.c
> +++ b/semihosting/uaccess.c
> @@ -14,13 +14,20 @@
>  void *softmmu_lock_user(CPUArchState *env, target_ulong addr,
>                          target_ulong len, bool copy)
>  {
> -    void *p = malloc(len);
> -    if (p && copy) {
> +    void *p = g_try_malloc(len);
> +
> +    if (!p) {
> +        p = NULL;

This doesn't make sense -- if (!p) means p is already NULL,
so you don't need to set it to NULL.

> +        return p;
> +    }

This patch should just replace malloc() with
g_try_malloc() and free() with g_free(). You don't need to
change any of the rest of the logic in the function.

> +
> +    if (copy) {
>          if (cpu_memory_rw_debug(env_cpu(env), addr, p, len, 0)) {
> -            free(p);
> +            g_free(p);
>              p = NULL;
>          }
>      }
> +
>      return p;
>  }
>
> @@ -87,5 +94,5 @@ void softmmu_unlock_user(CPUArchState *env, void *p,
>      if (len) {
>          cpu_memory_rw_debug(env_cpu(env), addr, p, len, 1);
>      }
> -    free(p);
> +    g_free(p);
>  }
> --
> 2.30.0.windows.2

thanks
-- PMM