Re: [Qemu-devel] [RFC v2 1/4] elf: Add optional function ptr to load_elf() to parse ELF notes

[Liam Merwick <liam.merwick@oracle.com>]

On 02/01/2019 13:06, Stefan Hajnoczi wrote:
> On Fri, Dec 21, 2018 at 08:03:49PM +0000, Liam Merwick wrote:
>> diff --git a/include/hw/elf_ops.h b/include/hw/elf_ops.h
>> index 74679ff8da3a..37d20a3800c1 100644
>> --- a/include/hw/elf_ops.h
>> +++ b/include/hw/elf_ops.h
>> @@ -266,6 +266,7 @@ fail:
>>   }
>>   
>>   static int glue(load_elf, SZ)(const char *name, int fd,
>> +                              uint64_t (*elf_note_fn)(void *, void *, bool),
>>                                 uint64_t (*translate_fn)(void *, uint64_t),
>>                                 void *translate_opaque,
>>                                 int must_swab, uint64_t *pentry,
>> @@ -496,8 +497,30 @@ static int glue(load_elf, SZ)(const char *name, int fd,
>>                   high = addr + mem_size;
>>   
>>               data = NULL;
>> +
>> +        } else if (ph->p_type == PT_NOTE && elf_note_fn) {
>> +            struct elf_note *nhdr = NULL;
>> +
>> +            file_size = ph->p_filesz; /* Size of the range of ELF notes */
>> +            data = g_malloc0(file_size);
>> +            if (ph->p_filesz > 0) {
>> +                if (lseek(fd, ph->p_offset, SEEK_SET) < 0) {
>> +                    goto fail;
>> +                }
>> +                if (read(fd, data, file_size) != file_size) {
>> +                    goto fail;
>> +                }
>> +            }
>> +
>> +            if (nhdr != NULL) {
>> +                bool is64 =
>> +                    sizeof(struct elf_note) == sizeof(struct elf64_note);
>> +                elf_note_fn((void *)nhdr, (void *)&ph->p_align, is64);
> 
> How does data get used?

Moved (as suggested in comments for next patch)

> 
>> +            }
>> +            g_free(data);
> 
> Missing data = NULL to prevent double free later?
> 

Added explicit assignment.

Regards,
Liam