On Thu, 2016-15-09 at 05:11:59 UTC, Michael Ellerman wrote:
> In our linker script we open code the list of text sections, because we
> need to include the __ftr_alt sections, which are arch-specific.
> This means we can't use TEXT_TEXT as defined in vmlinux.lds.h, and so we
> don't have the MEM_KEEP() logic for memory hotplug sections.
> If we build the kernel with the gold linker, and with CONFIG_MEMORY_HOTPLUG=y,
> we see that functions marked __meminit can end up outside of the
> _stext/_etext range, and also outside of _sinittext/_einittext, eg:
> c000000000000000 T _stext
> c0000000009e0000 A _etext
> c0000000009e3f18 T hash__vmemmap_create_mapping
> c000000000ca0000 T _sinittext
> c000000000d00844 T _einittext
> This causes them to not be recognised as text by is_kernel_text(), and
> prevents them being patched by jump_label (and presumably ftrace/kprobes
> Fix it by adding MEM_KEEP() directives, mirroring what TEXT_TEXT does.
> This isn't a problem when CONFIG_MEMORY_HOTPLUG=n, because we use the
> standard INIT_TEXT_SECTION() and EXIT_TEXT macros from vmlinux.lds.h.
> Signed-off-by: Michael Ellerman <m...@ellerman.id.au>
> Tested-by: Anton Blanchard <an...@samba.org>
Applied to powerpc next.