Messages in this thread |  | | Date | Thu, 17 Aug 2017 01:18:23 +0300 | From | "Kirill A. Shutemov" <> | Subject | Re: [PATCH] x86/boot/64: clang: use fixup_pointer() to access next_early_pgt |
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On Wed, Aug 16, 2017 at 09:08:08PM +0200, Alexander Potapenko wrote: > __startup_64() is normally using fixup_pointer() to access globals in a > position-independent fashion. However |next_early_pgt| was accessed > directly, which wasn't guaranteed to work. > > Luckily GCC was generating a R_X86_64_PC32 PC-relative relocation for > |next_early_pgt|, but Clang emitted a R_X86_64_32S, which led to > accessing invalid memory and rebooting the kernel.
Thanks for tracking this down.
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > Cc: Dmitry Vyukov <dvyukov@google.com> > Cc: Michael Davidson <md@google.com> > Fixes: c88d71508e36 ("x86/boot/64: Rewrite startup_64() in C")
Cc: <stable@vger.kernel.org> # 4.12
-- Kirill A. Shutemov
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