x86/kasan: Fix boot with KASAN=y and PROFILE_ANNOTATED_BRANCHES=y

The kernel doesn't boot with both PROFILE_ANNOTATED_BRANCHES=y and KASAN=y options selected. With branch profiling enabled we end up calling ftrace_likely_update() before kasan_early_init(). ftrace_likely_update() is built with KASAN instrumentation, so calling it before kasan has been initialized leads to crash. Use DISABLE_BRANCH_PROFILING define to make sure that we don't call ftrace_likely_update() from early code before kasan_early_init(). Fixes: ef7f0d6 ("x86_64: add KASan support") Reported-by: Fengguang Wu <[email protected]> Signed-off-by: Andrey Ryabinin <[email protected]> Cc: [email protected] Cc: Alexander Potapenko <[email protected]> Cc: [email protected] Cc: Andrew Morton <[email protected]> Cc: [email protected] Cc: Dmitry Vyukov <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Thomas Gleixner <[email protected]>
redbrain17 · Mar 13, 2017 · be3606f · be3606f
1 parent 859bb6d
commit be3606f
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diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
@@ -4,6 +4,7 @@
  *  Copyright (C) 2000 Andrea Arcangeli <[email protected]> SuSE
  */
 
+#define DISABLE_BRANCH_PROFILING
 #include <linux/init.h>
 #include <linux/linkage.h>
 #include <linux/types.h>

diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c
@@ -1,3 +1,4 @@
+#define DISABLE_BRANCH_PROFILING
 #define pr_fmt(fmt) "kasan: " fmt
 #include <linux/bootmem.h>
 #include <linux/kasan.h>