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authorVineet Gupta <vgupta@synopsys.com>2016-09-16 17:23:26 -0700
committerVineet Gupta <vgupta@synopsys.com>2016-09-30 14:48:22 -0700
commit5a205a32ffccf6e720a2d2b3aee44b16619016a6 (patch)
tree9ff1460c48ecbcc382405826ff53c5329bd5a9dd
parent2dad1122d9d936cf120953324eaaa38c3ab20ac2 (diff)
downloadop-kernel-dev-5a205a32ffccf6e720a2d2b3aee44b16619016a6.zip
op-kernel-dev-5a205a32ffccf6e720a2d2b3aee44b16619016a6.tar.gz
ARC: dw2 unwind: add infrastructure for adding cfi pseudo ops to asm
1. detect whether binutils supports the cfi pseudo ops 2. define conditional macros to generate the ops 3. define new ENTRY_CFI/END_CFI to annotate hand asm code. - Needed because we don't want to emit dwarf info in general ENTRY/END used by lowest level trap/exception/interrutp handlers as unwinder gets confused trying to unwind out of them. We want unwinder to instead stop when it hits onfo those routines - These provide minimal start/end cfi ops assuming routine doesn't touch stack memory/regs Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
-rw-r--r--arch/arc/Makefile3
-rw-r--r--arch/arc/include/asm/dwarf.h38
-rw-r--r--arch/arc/include/asm/linkage.h12
3 files changed, 52 insertions, 1 deletions
diff --git a/arch/arc/Makefile b/arch/arc/Makefile
index a2a6a46..aa82d13 100644
--- a/arch/arc/Makefile
+++ b/arch/arc/Makefile
@@ -65,7 +65,8 @@ endif
endif
-cflags-$(CONFIG_ARC_DW2_UNWIND) += -fasynchronous-unwind-tables
+cfi := $(call as-instr,.cfi_startproc\n.cfi_endproc,-DARC_DW2_UNWIND_AS_CFI)
+cflags-$(CONFIG_ARC_DW2_UNWIND) += -fasynchronous-unwind-tables $(cfi)
ifndef CONFIG_CC_OPTIMIZE_FOR_SIZE
# Generic build system uses -O2, we want -O3
diff --git a/arch/arc/include/asm/dwarf.h b/arch/arc/include/asm/dwarf.h
new file mode 100644
index 0000000..bb7bdbc
--- /dev/null
+++ b/arch/arc/include/asm/dwarf.h
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2016-17 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef _ASM_ARC_DWARF_H
+#define _ASM_ARC_DWARF_H
+
+#ifdef __ASSEMBLY__
+
+#ifdef ARC_DW2_UNWIND_AS_CFI
+
+#define CFI_STARTPROC .cfi_startproc
+#define CFI_ENDPROC .cfi_endproc
+#define CFI_DEF_CFA .cfi_def_cfa
+#define CFI_REGISTER .cfi_register
+#define CFI_REL_OFFSET .cfi_rel_offset
+#define CFI_UNDEFINED .cfi_undefined
+
+#else
+
+#define CFI_IGNORE #
+
+#define CFI_STARTPROC CFI_IGNORE
+#define CFI_ENDPROC CFI_IGNORE
+#define CFI_DEF_CFA CFI_IGNORE
+#define CFI_REGISTER CFI_IGNORE
+#define CFI_REL_OFFSET CFI_IGNORE
+#define CFI_UNDEFINED CFI_IGNORE
+
+#endif /* !ARC_DW2_UNWIND_AS_CFI */
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* _ASM_ARC_DWARF_H */
diff --git a/arch/arc/include/asm/linkage.h b/arch/arc/include/asm/linkage.h
index 5faad17..b29f1a9 100644
--- a/arch/arc/include/asm/linkage.h
+++ b/arch/arc/include/asm/linkage.h
@@ -9,6 +9,8 @@
#ifndef __ASM_LINKAGE_H
#define __ASM_LINKAGE_H
+#include <asm/dwarf.h>
+
#ifdef __ASSEMBLY__
#define ASM_NL ` /* use '`' to mark new line in macro */
@@ -32,6 +34,16 @@
#endif
.endm
+#define ENTRY_CFI(name) \
+ .globl name ASM_NL \
+ ALIGN ASM_NL \
+ name: ASM_NL \
+ CFI_STARTPROC ASM_NL
+
+#define END_CFI(name) \
+ CFI_ENDPROC ASM_NL \
+ .size name, .-name
+
#else /* !__ASSEMBLY__ */
#ifdef CONFIG_ARC_HAS_ICCM
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