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: ef7f0d6a6ca8 ("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]>

diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 54a2372f5dbb1eb0598788e944ad28708b638671..b5785c197e534796d5e477b6cd86a502d229db7c 100644 (file)
--- 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
index 8d63d7a104c3c445805dcf24a59fff2756a17b01..4c90cfdc128b832c6065cdb8830f89d16bff63dd 100644 (file)
--- 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>