Messages in this thread |  | | Date | Thu, 28 Apr 2016 11:37:41 +0200 | | From | Ingo Molnar <> | | Subject | Re: [PATCH v2] x86/boot: Rename overlapping memcpy() to memmove() |
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* Kees Cook <keescook@chromium.org> wrote:
> On Thu, Apr 28, 2016 at 2:04 AM, Ingo Molnar <mingo@kernel.org> wrote: > > > > * Kees Cook <keescook@chromium.org> wrote: > > > +#define memmove memmove > > > > Btw., what's the purpose of this define? If it's already defined then we should > > get a build warning. If it's not, we won't. > > It's for the decompressor that checks for memmove existing already via > "ifdef memmove". If this isn't done here, we will end up with two > memmove implementations.
So:
triton:~/tip> git grep memmove | grep -i ifdef triton:~/tip>
what am I missing?
> >> +void *memcpy(void *dest, const void *src, size_t n) > > > > btw., if there's any doubt about other overlapping uses, we could add this to > > memcpy(): > > > > WARN_ON_ONCE(dest > src && dest-src < n); > > > > or so? Does printk() work so early on? > > It does not, but we could use either "error" or the new "warn". Should > we abort a boot in this case, or just warn about it? (Our > implementations of memcpy, fwiw, currently seem to support overlap, so > I would suggest warn.)
Yeah, I'd definitely not try to crash the bootup for the user, but try to continue.
Thanks,
Ingo
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