This is the mail archive of the libc-alpha@sourceware.org mailing list for the glibc 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: RFC: __attribute_alloc_size__ on allocation functions (BZ#23741)


On 11/9/18 7:11 AM, Adhemerval Zanella wrote:
It seems that some*very*  specific programs do allocate objects larger PTRDIFF_MAX,

On the other hand, GNU coreutils, GNU Emacs and several other programs do just the opposite: they uses wrappers around malloc that fail without calling malloc if the requested size exceeds PTRDIFF_MAX. This is to avoid the compiler gotchas mentioned in this thread.

For almost all applications malloc and friends should never allocate such objects as they cause more problems than they cure. The very few applications that need and can safely use objects larger than PTRDIFF_MAX can use mmap. And for mmap, I wouldn't mind if glibc mmap added a flag MMAP_EXCEED_PTRDIFF, so that mmap could reject requests for sizes greater than PTRDIFF_MAX unless this new flag is used.


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