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authorMax Filippov <jcmvbkbc@gmail.com>2013-04-08 01:29:19 +0400
committerChris Zankel <chris@zankel.net>2013-05-09 01:07:10 -0700
commit3ae908c99e944a7a5c4f4b2d8c603a6bc57b728b (patch)
tree10159f1a9c02b862957d7d196cb1da6bb762ad39 /arch/xtensa/include/asm/ftrace.h
parent3e4196a5cc9cff50900f3dc8acc3d41e5963fd50 (diff)
xtensa: provide custom CALLER_ADDR* implementations
Definition of CALLER_ADDR* through __builtin_return_address makes compiler insert calls to __xtensa_libgcc_window_spill, which in turn makes fast_syscall_spill_registers syscall that clobbers registers when called from the kernel mode, leading to invalid opcode exceptions on return to userspace. Provide definition for CALLER_ADDR0 as MAKE_PC_FROM_RA(a0, a1) and in case CONFIG_FRAME_POINTER is enabled extract CALLER_ADDR{1-3} from stack. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Chris Zankel <chris@zankel.net>
Diffstat (limited to 'arch/xtensa/include/asm/ftrace.h')
-rw-r--r--arch/xtensa/include/asm/ftrace.h34
1 files changed, 33 insertions, 1 deletions
diff --git a/arch/xtensa/include/asm/ftrace.h b/arch/xtensa/include/asm/ftrace.h
index 40a8c178f10d..36dc7a684397 100644
--- a/arch/xtensa/include/asm/ftrace.h
+++ b/arch/xtensa/include/asm/ftrace.h
@@ -1 +1,33 @@
-/* empty */
+/*
+ * arch/xtensa/include/asm/ftrace.h
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2013 Tensilica Inc.
+ */
+#ifndef _XTENSA_FTRACE_H
+#define _XTENSA_FTRACE_H
+
+#include <asm/processor.h>
+
+#define HAVE_ARCH_CALLER_ADDR
+#define CALLER_ADDR0 ({ unsigned long a0, a1; \
+ __asm__ __volatile__ ( \
+ "mov %0, a0\n" \
+ "mov %1, a1\n" \
+ : "=r"(a0), "=r"(a1) : : ); \
+ MAKE_PC_FROM_RA(a0, a1); })
+#ifdef CONFIG_FRAME_POINTER
+extern unsigned long return_address(unsigned level);
+#define CALLER_ADDR1 return_address(1)
+#define CALLER_ADDR2 return_address(2)
+#define CALLER_ADDR3 return_address(3)
+#else
+#define CALLER_ADDR1 (0)
+#define CALLER_ADDR2 (0)
+#define CALLER_ADDR3 (0)
+#endif
+
+#endif /* _XTENSA_FTRACE_H */