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@google.com --- 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);