On Fri, 9 Feb 2018, Eric Biggers wrote:
> This is a build fix for the 4.4 PTI backport. 4.4 kernels do not have
> commit be7635e7287e ("arch, ftrace: for KASAN put hard/soft IRQ entries
> into separate sections") which went into 4.6. Consequently, the
> irqentry sections are only created when CONFIG_FUNCTION_GRAPH_TRACER is
> enabled, not also when CONFIG_KASAN is enabled. Therefore, fix the
> condition for trying to add a user mapping for this section.
>
> This fixes the following build error:
>
> arch/x86/mm/kaiser.c: In function ‘kaiser_init’:
> arch/x86/mm/kaiser.c:367:33: error: ‘__irqentry_text_start’ undeclared (first use in this function)
> kaiser_add_user_map_ptrs_early(__irqentry_text_start,
> [...]
>
> Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Yep, sorry about that, thanks Eric:
Acked-by: Hugh Dickins <hughd@xxxxxxxxxx>
> ---
> arch/x86/mm/kaiser.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/mm/kaiser.c b/arch/x86/mm/kaiser.c
> index 2298434f7bdb..7a72e32e4806 100644
> --- a/arch/x86/mm/kaiser.c
> +++ b/arch/x86/mm/kaiser.c
> @@ -363,7 +363,7 @@ void __init kaiser_init(void)
> kaiser_add_user_map_ptrs_early(__entry_text_start, __entry_text_end,
> __PAGE_KERNEL_RX);
>
> -#if defined(CONFIG_FUNCTION_GRAPH_TRACER) || defined(CONFIG_KASAN)
> +#ifdef CONFIG_FUNCTION_GRAPH_TRACER
> kaiser_add_user_map_ptrs_early(__irqentry_text_start,
> __irqentry_text_end,
> __PAGE_KERNEL_RX);
> --
> 2.16.0.rc1.238.g530d649a79-goog