Re: [Qemu-devel] [PATCH 4/4] linux-user: Fix error handling in target_to_host_semarray()

[Peter Maydell]

On 18 February 2014 15:10, Riku Voipio <address@hidden> wrote:
> On Mon, Feb 17, 2014 at 06:55:34PM +0000, Peter Maydell wrote:
>> Fix two issues in error handling in target_to_host_semarray():
>>  * don't leak the host_array buffer if lock_user fails
>>  * return an error if malloc() fails
>
> With this patch I get on ubuntu raring x86_64 (gcc 4.7):
>
> In function ‘target_to_host_semarray’,
>     inlined from ‘do_semctl’ at 
> /home/voipio/linaro/qemu/linux-user/syscall.c:2502:17,
>     inlined from ‘do_syscall’ at 
> /home/voipio/linaro/qemu/linux-user/syscall.c:6917:13:
> /home/voipio/linaro/qemu/linux-user/syscall.c:2439:13: error: attempt to free 
> a non-heap object ‘array’ [-Werror=free-nonheap-object]
> cc1: all warnings being treated as errors

Doh. Missing '*':

>>
>>      *host_array = malloc(nsems*sizeof(unsigned short));
>> +    if (!*host_array) {
>> +        return -TARGET_ENOMEM;
>> +    }
>>      array = lock_user(VERIFY_READ, target_addr,
>>                        nsems*sizeof(unsigned short), 1);
>> -    if (!array)
>> +    if (!array) {
>> +        free(host_array);

...should be
    free(*host_array);

thanks
-- PMM