On Thu, Jun 21, 2018 at 05:25:08PM -0400, Pavel Tatashin wrote:
> ---
> arch/x86/include/asm/text-patching.h | 1 +
> arch/x86/kernel/alternative.c | 10 +++++++++-
> 2 files changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/include/asm/text-patching.h
> b/arch/x86/include/asm/text-patching.h
> index 2ecd34e2d46c..e85ff65c43c3 100644
> --- a/arch/x86/include/asm/text-patching.h
> +++ b/arch/x86/include/asm/text-patching.h
> @@ -37,5 +37,6 @@ extern void *text_poke_early(void *addr, const void
> *opcode, size_t len);
> extern void *text_poke(void *addr, const void *opcode, size_t len);
> extern int poke_int3_handler(struct pt_regs *regs);
> extern void *text_poke_bp(void *addr, const void *opcode, size_t len, void
> *handler);
> +extern int after_bootmem;
>
> #endif /* _ASM_X86_TEXT_PATCHING_H */
> diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
> index a481763a3776..0230dbc3c599 100644
> --- a/arch/x86/kernel/alternative.c
> +++ b/arch/x86/kernel/alternative.c
> @@ -686,13 +686,21 @@ void *__init_or_module text_poke_early(void *addr,
> const void *opcode,
> *
> * Note: Must be called under text_mutex.
> */
> -void *text_poke(void *addr, const void *opcode, size_t len)
> +void __ref *text_poke(void *addr, const void *opcode, size_t len)
> {
> unsigned long flags;
> char *vaddr;
> struct page *pages[2];
> int i;
>
> + /* While boot memory allocator is runnig we cannot use struct
Broken comment style..
> + * pages as they are not yet initialized. However, we also know
> + * that this is early in boot, and it is safe to fallback to
> + * text_poke_early.
> + */
> + if (unlikely(!after_bootmem))
> + return text_poke_early(addr, opcode, len);
I'm not entirely sure this is right.. Because not only do we need the
whole fixmap stuff working, we also need #DB and the IPI handlers set-up
and working.
Also, why do this here and not override @poker in
__jump_label_transform() ?
And I added a sync_core() in text_poke_early(), which I think we need
for this.
> if (!core_kernel_text((unsigned long)addr)) {
> pages[0] = vmalloc_to_page(addr);
> pages[1] = vmalloc_to_page(addr + PAGE_SIZE);
> --
> 2.17.1
>
