[libc-commits] [PATCH] D127517: [libc] add integer writing to printf

David Finkelstein via Phabricator via libc-commits libc-commits at lists.llvm.org
Fri Jun 10 17:58:00 PDT 2022

dxf added a comment.

You could certainly do something like that.

FORTIFY_SOURCE is a long-established way of inserting a relatively low-cost runtime check to a number of libc functions.  The compiler can also do some static checks and it can also decide things like "should this call to mempcpy() invoke the regular mempcpy(), or the one with extra checks?" and not simply call the one with extra checks every time.

For many projects, a "hardened" libc is nice but not sufficient, and they use tools like ASan instead (which can help catch memory problems across all the code and not just in the libc functions).

I think if we want to have "safe" versions of these functions we should do it via the FORTIFY_SOURCE mechanism since both glibc and bionic support it.  LLVM's libc could carry code (like glibc and bionic) to support FORTIFY, if someone wants to contribute those patches. There might be other ways to achieve the same functionality.  I'd like to continue this discussion, but that's probably best done on discourse.

  rG LLVM Github Monorepo



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