commit dad5647a8ca3d5897aae0845343d4ec9e415389b
author Todd Poynor <toddpoynor@google.com> Wed Jul 03 15:48:04 2013 -0700
committer Dmitry Shmidt <dimitrysh@google.com> Fri Jan 27 13:51:28 2017 -0800
tree 7414b0173ee68d0e9b6f7ba710f6c29eb3f053cb
parent 053d5478aa7e7342a19f29d3e0871fb94f1de862

ANDROID: ARM: kgdb: ignore breakpoint instructions from user mode

Avoid conflicts with user mode usage of the same instructions, as with
Clang -ftrapv.

Change-Id: I12d1c6d8f94376bfd2503cb0be843d7e478fb6ea
Signed-off-by: Todd Poynor <toddpoynor@google.com>

arch/arm/kernel/kgdb.c

diff --git a/arch/arm/kernel/kgdb.c b/arch/arm/kernel/kgdb.c
index 9232cae..f3c6622 100644
--- a/arch/arm/kernel/kgdb.c
+++ b/arch/arm/kernel/kgdb.c
@@ -140,6 +140,8 @@
 
 static int kgdb_brk_fn(struct pt_regs *regs, unsigned int instr)
 {
+	if (user_mode(regs))
+		return -1;
 	kgdb_handle_exception(1, SIGTRAP, 0, regs);
 
 	return 0;
@@ -147,6 +149,8 @@
 
 static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int instr)
 {
+	if (user_mode(regs))
+		return -1;
 	compiled_break = 1;
 	kgdb_handle_exception(1, SIGTRAP, 0, regs);