[PATCH 4.19 44/85] arm64: unwind: Prohibit probing on return_address()

Greg Kroah-Hartman
2019-08-22T17:30:05Z

[ Upstream commit ee07b93e7721ccd5d5b9fa6f0c10cb3fe2f1f4f9 ]

Prohibit probing on return_address() and subroutines which
is called from return_address(), since the it is invoked from
trace_hardirqs_off() which is also kprobe blacklisted.

Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/arm64/kernel/return_address.c | 3 +++
arch/arm64/kernel/stacktrace.c | 3 +++
2 files changed, 6 insertions(+)

diff --git a/arch/arm64/kernel/return_address.c b/arch/arm64/kernel/return_address.c
index 933adbc0f654d..0311fe52c8ffb 100644
--- a/arch/arm64/kernel/return_address.c
+++ b/arch/arm64/kernel/return_address.c
@@ -11,6 +11,7 @@

#include <linux/export.h>
#include <linux/ftrace.h>
+#include <linux/kprobes.h>

#include <asm/stack_pointer.h>
#include <asm/stacktrace.h>
@@ -32,6 +33,7 @@ static int save_return_addr(struct stackframe *frame, void *d)
return 0;
}
}
+NOKPROBE_SYMBOL(save_return_addr);

void *return_address(unsigned int level)
{
@@ -55,3 +57,4 @@ void *return_address(unsigned int level)
return NULL;
}
EXPORT_SYMBOL_GPL(return_address);
+NOKPROBE_SYMBOL(return_address);
diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index 4989f7ea1e599..bb482ec044b61 100644
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -18,6 +18,7 @@
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/ftrace.h>
+#include <linux/kprobes.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/sched/task_stack.h>
@@ -85,6 +86,7 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame)

return 0;
}
+NOKPROBE_SYMBOL(unwind_frame);

void notrace walk_stackframe(struct task_struct *tsk, struct stackframe *frame,
int (*fn)(struct stackframe *, void *), void *data)
@@ -99,6 +101,7 @@ void notrace walk_stackframe(struct task_struct *tsk, struct stackframe *frame,
break;
}
}
+NOKPROBE_SYMBOL(walk_stackframe);

#ifdef CONFIG_STACKTRACE
struct stack_trace_data {
--
2.20.1