From: Michael Ellerman Date: Thu, 15 Sep 2016 05:11:59 +0000 (+1000) Subject: powerpc: Ensure .mem(init|exit).text are within _stext/_etext X-Git-Tag: v4.9-rc1~26^2~136 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=7de3b27bac47da9de08409df1d69664acbb72197;p=linux-block.git powerpc: Ensure .mem(init|exit).text are within _stext/_etext 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 etc.). 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 Tested-by: Anton Blanchard Signed-off-by: Michael Ellerman --- diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S index b5fba689fca6..b59d75e194a5 100644 --- a/arch/powerpc/kernel/vmlinux.lds.S +++ b/arch/powerpc/kernel/vmlinux.lds.S @@ -56,6 +56,8 @@ SECTIONS KPROBES_TEXT IRQENTRY_TEXT SOFTIRQENTRY_TEXT + MEM_KEEP(init.text) + MEM_KEEP(exit.text) #ifdef CONFIG_PPC32 *(.got1)