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