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authorPaul Mundt <lethal@linux-sh.org>2009-10-13 13:10:14 +0900
committerPaul Mundt <lethal@linux-sh.org>2009-10-13 13:10:14 +0900
commitac4fac8cb24ab209ae373a3e3e9995dff7d0c394 (patch)
tree705fbf8cbb583bb3d055cd38dec813e19a746c1f
parent5852b203ef1b85a8eacc1cc686ed9bac11ee31cc (diff)
sh: Generalize CALLER_ADDRx support.
This splits out the unwinder implementation and adds a new return_address() abstraction modelled after the ARM code. The DWARF unwinder is tied in to this, returning NULL otherwise in the case of being unable to support arbitrary depths. This enables us to get correct behaviour with the unwinder enabled, as well as disabling the arbitrary depth support when frame pointers are enabled, as arbitrary depths with __builtin_return_address() are not supported regardless. With this abstraction it's also possible to layer on a simplified implementation with frame pointers in the event that the unwinder isn't enabled, although this is left as a future exercise. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
-rw-r--r--arch/sh/include/asm/dwarf.h5
-rw-r--r--arch/sh/include/asm/ftrace.h50
-rw-r--r--arch/sh/kernel/Makefile1
-rw-r--r--arch/sh/kernel/return_address.c54
4 files changed, 68 insertions, 42 deletions
diff --git a/arch/sh/include/asm/dwarf.h b/arch/sh/include/asm/dwarf.h
index fc51e66f2380..d985148af19f 100644
--- a/arch/sh/include/asm/dwarf.h
+++ b/arch/sh/include/asm/dwarf.h
@@ -194,6 +194,11 @@
#define DWARF_ARCH_RA_REG 17
#ifndef __ASSEMBLY__
+
+#include <linux/compiler.h>
+#include <linux/bug.h>
+#include <linux/list.h>
+
/*
* Read either the frame pointer (r14) or the stack pointer (r15).
* NOTE: this MUST be inlined.
diff --git a/arch/sh/include/asm/ftrace.h b/arch/sh/include/asm/ftrace.h
index 5ea9030725c0..28875a3e4116 100644
--- a/arch/sh/include/asm/ftrace.h
+++ b/arch/sh/include/asm/ftrace.h
@@ -32,52 +32,18 @@ static inline unsigned long ftrace_call_adjust(unsigned long addr)
return addr;
}
-
-#ifdef CONFIG_DWARF_UNWINDER
-#include <asm/dwarf.h>
+/* arch/sh/kernel/return_address.c */
+extern void *return_address(unsigned int);
#define HAVE_ARCH_CALLER_ADDR
-static inline unsigned long dwarf_return_address(int depth)
-{
- struct dwarf_frame *frame;
- unsigned long ra;
- int i;
-
- for (i = 0, frame = NULL, ra = 0; i <= depth; i++) {
- struct dwarf_frame *tmp;
-
- tmp = dwarf_unwind_stack(ra, frame);
-
- if (frame)
- dwarf_free_frame(frame);
-
- frame = tmp;
-
- if (!frame || !frame->return_addr)
- break;
-
- ra = frame->return_addr;
- }
-
- /* Failed to unwind the stack to the specified depth. */
- WARN_ON(i != depth + 1);
-
- if (frame)
- dwarf_free_frame(frame);
-
- return ra;
-}
-
#define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
-#define CALLER_ADDR1 dwarf_return_address(1)
-#define CALLER_ADDR2 dwarf_return_address(2)
-#define CALLER_ADDR3 dwarf_return_address(3)
-#define CALLER_ADDR4 dwarf_return_address(4)
-#define CALLER_ADDR5 dwarf_return_address(5)
-#define CALLER_ADDR6 dwarf_return_address(6)
-
-#endif /* CONFIG_DWARF_UNWINDER */
+#define CALLER_ADDR1 ((unsigned long)return_address(1))
+#define CALLER_ADDR2 ((unsigned long)return_address(2))
+#define CALLER_ADDR3 ((unsigned long)return_address(3))
+#define CALLER_ADDR4 ((unsigned long)return_address(4))
+#define CALLER_ADDR5 ((unsigned long)return_address(5))
+#define CALLER_ADDR6 ((unsigned long)return_address(6))
#endif /* __ASSEMBLY__ */
#endif /* CONFIG_FUNCTION_TRACER */
diff --git a/arch/sh/kernel/Makefile b/arch/sh/kernel/Makefile
index a2d0a40f3848..18a1e279b430 100644
--- a/arch/sh/kernel/Makefile
+++ b/arch/sh/kernel/Makefile
@@ -11,6 +11,7 @@ endif
obj-y := debugtraps.o dumpstack.o idle.o io.o io_generic.o irq.o \
machvec.o nmi_debug.o process_$(BITS).o ptrace_$(BITS).o \
+ return_address.o \
setup.o signal_$(BITS).o sys_sh.o sys_sh$(BITS).o \
syscalls_$(BITS).o time.o topology.o traps.o \
traps_$(BITS).o unwinder.o
diff --git a/arch/sh/kernel/return_address.c b/arch/sh/kernel/return_address.c
new file mode 100644
index 000000000000..df3ab5811074
--- /dev/null
+++ b/arch/sh/kernel/return_address.c
@@ -0,0 +1,54 @@
+/*
+ * arch/sh/kernel/return_address.c
+ *
+ * Copyright (C) 2009 Matt Fleming
+ * Copyright (C) 2009 Paul Mundt
+ *
+ * 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.
+ */
+#include <linux/kernel.h>
+#include <asm/dwarf.h>
+
+#ifdef CONFIG_DWARF_UNWINDER
+
+void *return_address(unsigned int depth)
+{
+ struct dwarf_frame *frame;
+ unsigned long ra;
+ int i;
+
+ for (i = 0, frame = NULL, ra = 0; i <= depth; i++) {
+ struct dwarf_frame *tmp;
+
+ tmp = dwarf_unwind_stack(ra, frame);
+
+ if (frame)
+ dwarf_free_frame(frame);
+
+ frame = tmp;
+
+ if (!frame || !frame->return_addr)
+ break;
+
+ ra = frame->return_addr;
+ }
+
+ /* Failed to unwind the stack to the specified depth. */
+ WARN_ON(i != depth + 1);
+
+ if (frame)
+ dwarf_free_frame(frame);
+
+ return (void *)ra;
+}
+
+#else
+
+void *return_address(unsigned int depth)
+{
+ return NULL;
+}
+
+#endif