Add symbol to mark end of entry_*.S and use the same to blacklist all
addresses from kernel start (_stext) to entry code from kprobes. Much of
this code is early exception handling where we can't really take a trap.
Reported-by: Anton Blanchard <an...@samba.org>
Signed-off-by: Naveen N. Rao <naveen.n....@linux.vnet.ibm.com>
---
arch/powerpc/kernel/entry_32.S | 2 ++
arch/powerpc/kernel/entry_64.S | 2 ++
arch/powerpc/kernel/kprobes.c | 10 ++++++++++
3 files changed, 14 insertions(+)
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 3841d74..de1ed6e 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -1410,3 +1410,5 @@ _GLOBAL(return_to_handler)
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
#endif /* CONFIG_FUNCTION_TRACER */
+
+_GLOBAL_SYM(__entry_text_end)
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 6432d4b..f5f99920 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -1551,3 +1551,5 @@ _GLOBAL(return_to_handler)
blr
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
#endif /* CONFIG_FUNCTION_TRACER */
+
+_GLOBAL_SYM(__entry_text_end)
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index 9479d8e..b5173d6 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -36,12 +36,22 @@
#include <asm/cacheflush.h>
#include <asm/sstep.h>
#include <asm/uaccess.h>
+#include <asm/sections.h>
DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
struct kretprobe_blackpoint kretprobe_blacklist[] = {{NULL, NULL}};
+bool arch_within_kprobe_blacklist(unsigned long addr)
+{
+ /* The __kprobes marked functions and entry code must not be probed */
+ return (addr >= (unsigned long)__kprobes_text_start &&
+ addr < (unsigned long)__kprobes_text_end) ||
+ (addr >= (unsigned long)_stext &&
+ addr < (unsigned long)__entry_text_end);
+}
+
int __kprobes arch_prepare_kprobe(struct kprobe *p)
{
int ret = 0;
--
2.10.2
