This is the mail archive of the mailing list for the GCC project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [PATCH, libgfortran] Add overflow check to xmalloc

>> On Tue, May 20, 2014 at 12:42 AM, Janne Blomqvist
>> <> wrote:
>>> On Thu, May 15, 2014 at 1:00 AM, Janne Blomqvist
>>> <> wrote:
>>>> Hi,
>>>> a common malloc() pattern is "malloc(num_foo * sizeof(foo_t)", that
>>>> is, create space for an array of type foo_t with num_foo elements.
>>>> There is a slight danger here in that the multiplication can overflow
>>>> and wrap around, and then the caller thinks it has a larger array than
>>>> what malloc has actually created. The attached patch changes the
>>>> libgfortran xmalloc() function to have an API similar to calloc() with
>>>> two arguments, and the implementation checks for wraparound.
>>> Hello,
>>> attached is an updated patch which instead introduces a new function,
>>> xmallocarray, with the overflow check, and leaves the existing xmalloc
>>> as is. Thus avoiding the extra checking in the common case where one
>>> of the arguments to xmallocarray would be 1.
>>> Tested on x86_64-unknown-linux-gnu, Ok for trunk?

I would prefer if xcmalloc would not be named xmallocarray.


Sent with AquaMail for Android

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]