Re: [Qemu-devel] [PATCH v4 06/10] slirp/misc: check return value of malloc()

[zhanghailiang <zhang.zhanghailiang@huawei.com>]

On 2014/8/8 17:43, Alex Bennée wrote:
>
> zhanghailiang writes:
>
>> Signed-off-by: zhanghailiang<zhang.zhanghailiang@huawei.com>
>> ---
>>   slirp/misc.c | 9 +++++++--
>>   1 file changed, 7 insertions(+), 2 deletions(-)
>>
>> diff --git a/slirp/misc.c b/slirp/misc.c
>> index b8eb74c..9b457ad 100644
>> --- a/slirp/misc.c
>> +++ b/slirp/misc.c
>> @@ -55,6 +55,10 @@ int add_exec(struct ex_list **ex_ptr, int do_pty, char *exec,
>>
>>   	tmp_ptr = *ex_ptr;
>>   	*ex_ptr = (struct ex_list *)malloc(sizeof(struct ex_list));
>> +    if (*ex_ptr == NULL) {
>> +        fprintf(stderr, "Error: malloc failed\n");
>> +        return -1;
>> +    }
>
> Your indenting has gone a bit weird there.

Hmm, this file has some places that use tab key as indent.
Here i used spaces as indent, otherwise the patch can not pass the check 
of '/scripts/checkpatch.pl'.

What's your opinion? Use tab as what it does? Thanks!

>
>>   	(*ex_ptr)->ex_fport = port;
>>   	(*ex_ptr)->ex_addr = addr;
>>   	(*ex_ptr)->ex_pty = do_pty;
>> @@ -236,8 +240,9 @@ strdup(str)
>>   	char *bptr;
>>
>>   	bptr = (char *)malloc(strlen(str)+1);
>> -	strcpy(bptr, str);
>> -
>> +    if (bptr) {
>> +        strcpy(bptr, str);
>> +    }
>>   	return bptr;
>>   }
>>   #endif
>
> Again use of g_malloc would remove the need for this. HACKING section 3
> says:
>

OK, Thanks!

> 3. Low level memory management
>
> Use of the malloc/free/realloc/calloc/valloc/memalign/posix_memalign
> APIs is not allowed in the QEMU codebase. Instead of these routines,
> use the GLib memory allocation routines g_malloc/g_malloc0/g_new/
> g_new0/g_realloc/g_free or QEMU's qemu_memalign/qemu_blockalign/qemu_vfree
> APIs.
>
> Please note that g_malloc will exit on allocation failure, so there
> is no need to test for failure (as you would have to with malloc).
> Calling g_malloc with a zero size is valid and will return NULL.
>
>