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authorMarcel Ziswiler <marcel.ziswiler@toradex.com>2017-06-17 17:01:11 +0200
committerMarcel Ziswiler <marcel.ziswiler@toradex.com>2017-06-17 17:01:11 +0200
commitc1d5fe2d54551b95b812143d94d8168da2220dd8 (patch)
treefdde4472ab2b19fcadaae22d68a0c9b008f74373 /arch/x86/kernel/ftrace.c
parent0068a1b36d309f22698f7de7478b72e672360129 (diff)
parent1bd30958ec55d80ca72d2ca4e7e5c3d9fbf3173e (diff)
Merge tag 'v4.4.73' into toradex_vf_4.4-nextColibri-VF_LXDE-Image_2.7b3-20170630
This is the 4.4.73 stable release
Diffstat (limited to 'arch/x86/kernel/ftrace.c')
-rw-r--r--arch/x86/kernel/ftrace.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 311bcf338f07..bfc587579dc3 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -977,6 +977,18 @@ void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent,
unsigned long return_hooker = (unsigned long)
&return_to_handler;
+ /*
+ * When resuming from suspend-to-ram, this function can be indirectly
+ * called from early CPU startup code while the CPU is in real mode,
+ * which would fail miserably. Make sure the stack pointer is a
+ * virtual address.
+ *
+ * This check isn't as accurate as virt_addr_valid(), but it should be
+ * good enough for this purpose, and it's fast.
+ */
+ if (unlikely((long)__builtin_frame_address(0) >= 0))
+ return;
+
if (unlikely(ftrace_graph_is_dead()))
return;