Re: [PATCH 5/5] target/ppc/kvm: Replace alloca() by g_malloc()

[Philippe Mathieu-Daudé]

On 5/6/21 10:41 AM, Greg Kurz wrote:
> On Wed,  5 May 2021 19:00:55 +0200
> Philippe Mathieu-Daudé <philmd@redhat.com> wrote:
> 
>> The ALLOCA(3) man-page mentions its "use is discouraged".
>>
>> Replace it by a g_malloc() call.
>>
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>> ---
>>  target/ppc/kvm.c | 10 +++++-----
>>  1 file changed, 5 insertions(+), 5 deletions(-)
>>
>> diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
>> index 104a308abb5..ae62daddf7d 100644
>> --- a/target/ppc/kvm.c
>> +++ b/target/ppc/kvm.c
>> @@ -2698,11 +2698,11 @@ int kvmppc_save_htab(QEMUFile *f, int fd, size_t 
>> bufsize, int64_t max_ns)
>>  int kvmppc_load_htab_chunk(QEMUFile *f, int fd, uint32_t index,
>>                             uint16_t n_valid, uint16_t n_invalid, Error 
>> **errp)
>>  {
>> -    struct kvm_get_htab_header *buf;
>> -    size_t chunksize = sizeof(*buf) + n_valid * HASH_PTE_SIZE_64;
>> +    size_t chunksize = sizeof(struct kvm_get_htab_header)
> 
> It is a bit unfortunate to introduce a new dependency on the struct type.
> 
> What about the following ?
> 
> -    struct kvm_get_htab_header *buf;
> +    g_autofree struct kvm_get_htab_header *buf = NULL;
>      size_t chunksize = sizeof(*buf) + n_valid * HASH_PTE_SIZE_64;
>      ssize_t rc;
>  
> -    buf = alloca(chunksize);
> +    buf = g_malloc(chunksize);

OK.