On 04/06/2018 09:07 AM, Wei Liu wrote:
> On Fri, Apr 06, 2018 at 08:39:53AM -0400, Boris Ostrovsky wrote:
>> On 04/04/2018 09:50 PM, Marek Marczykowski-Górecki wrote:
>>> gcc-8 complains:
>>>
>>> kdd.c:698:13: error: 'memcpy' offset [-204, -717] is out of the bounds
>>> [0, 216] of object 'ctrl' with type 'kdd_ctrl' {aka 'union <anonymous>'}
>>> [-Werror=array-bounds]
>>> memcpy(buf, ((uint8_t *)&ctrl.c32) + offset, len);
>>> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>> kdd.c: In function 'kdd_select_callback':
>>> kdd.c:642:14: note: 'ctrl' declared here
>>> kdd_ctrl ctrl;
>>> ^~~~
>>>
>>> But this is impossible - 'offset' is unsigned and correctly validated
>>> few lines before.
>>>
>>> Signed-off-by: Marek Marczykowski-Górecki <marma...@invisiblethingslab.com>
>>> ---
>>> tools/debugger/kdd/kdd.c | 3 +++
>>> 1 file changed, 3 insertions(+)
>>>
>>> diff --git a/tools/debugger/kdd/kdd.c b/tools/debugger/kdd/kdd.c
>>> index 1bd5dd5..61d769e 100644
>>> --- a/tools/debugger/kdd/kdd.c
>>> +++ b/tools/debugger/kdd/kdd.c
>>> @@ -695,7 +695,10 @@ static void kdd_handle_read_ctrl(kdd_state *s)
>>> KDD_LOG(s, "Request outside of known control space\n");
>>> len = 0;
>>> } else {
>>> +#pragma GCC diagnostic push
>>> +#pragma GCC diagnostic ignored "-Warray-bounds"
>>> memcpy(buf, ((uint8_t *)&ctrl.c32) + offset, len);
>>> +#pragma GCC diagnostic pop
>>> }
>>> }
>>>
>>
>> Breaks 32-bit build, at least with my (ancient, gcc version 4.4.5
>> 20101112 (Red Hat 4.4.5-2) (GCC)) compiler:
>>
>>
>>
>> kdd.c: In function ‘kdd_handle_read_ctrl’:
>> kdd.c:698: error: #pragma GCC diagnostic not allowed inside functions
>> kdd.c:699: error: #pragma GCC diagnostic not allowed inside functions
>> kdd.c:701: error: #pragma GCC diagnostic not allowed inside functions
>> make[5]: *** [kdd.o] Error 1
>>
> Does moving the relevant #pragma's outside of the function fix it?
The additional problem with these pragmas is that apparently push/pop
have been introduced in gcc 4.6.0:
https://gcc.gnu.org/onlinedocs/gcc-4.6.0/gcc/Diagnostic-Pragmas.html#Diagnostic-Pragmas
If you change release number to a lower one (e.g. 4.5.4) you won't see them.
So I can move "diagnostic ignored" from inside the function and that
will clear the "GCC diagnostic not allowed inside functions" error. But
then push/pop are not recognized:
cc1: warnings being treated as errors
kdd.c:639: error: expected [error|warning|ignored] after ‘#pragma GCC
diagnostic’
kdd.c:714: error: expected [error|warning|ignored] after ‘#pragma GCC
diagnostic’
(Interestingly, my 64-bit build completed without issues)
-boris
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