Laurent Vivier <[email protected]> writes:

> Le 30/07/2018 à 15:43, Alex Bennée a écrit:
>> I've slightly re-organised the check to more closely match the
>> sequence that the kernel uses in do_mmap(). We check for both the zero
>> case (EINVAL) and the overflow length case (ENOMEM).
>>
>> Signed-off-by: Alex Bennée <[email protected]>
>> Cc: umarcor <[email protected]>
>>
>> ---
>> v2
>>   - add comment on overflow
>> ---
>>  linux-user/mmap.c | 15 ++++++++++++---
>>  1 file changed, 12 insertions(+), 3 deletions(-)
>>
>> diff --git a/linux-user/mmap.c b/linux-user/mmap.c
>> index d0c50e4888..41e0983ce8 100644
>> --- a/linux-user/mmap.c
>> +++ b/linux-user/mmap.c
>> @@ -391,14 +391,23 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, 
>> int prot,
>>      }
>>  #endif
>>
>> -    if (offset & ~TARGET_PAGE_MASK) {
>> +    if (!len) {
>>          errno = EINVAL;
>>          goto fail;
>>      }
>>
>> +    /* Also check for overflows... */
>>      len = TARGET_PAGE_ALIGN(len);
>> -    if (len == 0)
>> -        goto the_end;
>> +    if (!len) {
>> +        errno = ENOMEM;
>> +        goto fail;
>> +    }
>> +
>> +    if (offset & ~TARGET_PAGE_MASK) {
>> +        errno = EINVAL;
>> +        goto fail;
>> +    }
>> +
>>      real_start = start & qemu_host_page_mask;
>>      host_offset = offset & qemu_host_page_mask;
>>
>>
>
> Reviewed-by: Laurent Vivier <[email protected]>

Are you going to take this via your queue or do you want me to re-post
with the r-b?

--
Alex Bennée

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https://bugs.launchpad.net/bugs/1783362

Title:
  qemu-user: mmap should return failure (MAP_FAILED, -1) instead of
  success (NULL, 0) when len==0

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