Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   madvenka@linux.microsoft.com
To:     jpoimboe@redhat.com, peterz@infradead.org, chenzhongjin@huawei.com,
        mark.rutland@arm.com, broonie@kernel.org, nobuta.keiya@fujitsu.com,
        sjitindarsingh@gmail.com, catalin.marinas@arm.com, will@kernel.org,
        jamorris@linux.microsoft.com, linux-arm-kernel@lists.infradead.org,
        live-patching@vger.kernel.org, linux-kernel@vger.kernel.org,
        madvenka@linux.microsoft.com
Subject: [RFC PATCH v2 05/20] objtool: Reorganize ORC types
Date:   Mon, 23 May 2022 19:16:22 -0500
Message-Id: <20220524001637.1707472-6-madvenka@linux.microsoft.com>
In-Reply-To: <20220524001637.1707472-1-madvenka@linux.microsoft.com>
References: <e81e773678f88f7c2ff7480e2eb096973ec198db>
 <20220524001637.1707472-1-madvenka@linux.microsoft.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: "Madhavan T. Venkataraman" <madvenka@linux.microsoft.com>

The ORC code needs to be reorganized into arch-specific and generic parts
so that architectures other than X86 can use the generic parts.

orc_types.h contains the following ORC definitions shared between objtool
and the kernel:

	- ORC register definitions which are arch-specific.
	- orc_entry structure which is generic.

Move orc_entry into a new file include/linux/orc_entry.h. Also, the field
names bp_reg and bp_offset in struct orc_entry are x86-specific. Change
them to fp_reg and fp_offset. FP stands for frame pointer.

Currently, the type field in orc_entry is only 2 bits. For other
architectures, we will need more. So, expand this to 3 bits.

Signed-off-by: Madhavan T. Venkataraman <madvenka@linux.microsoft.com>
---
 arch/x86/include/asm/orc_types.h       | 37 +++++-------------------
 include/linux/orc_entry.h              | 39 ++++++++++++++++++++++++++
 tools/arch/x86/include/asm/orc_types.h | 37 +++++-------------------
 tools/include/linux/orc_entry.h        | 39 ++++++++++++++++++++++++++
 tools/objtool/orc_gen.c                |  4 +--
 tools/objtool/sync-check.sh            |  1 +
 6 files changed, 95 insertions(+), 62 deletions(-)
 create mode 100644 include/linux/orc_entry.h
 create mode 100644 tools/include/linux/orc_entry.h

diff --git a/arch/x86/include/asm/orc_types.h b/arch/x86/include/asm/orc_types.h
index 5a2baf28a1dc..851c9fb9f695 100644
--- a/arch/x86/include/asm/orc_types.h
+++ b/arch/x86/include/asm/orc_types.h
@@ -8,6 +8,13 @@
 
 #include <linux/types.h>
 #include <linux/compiler.h>
+#include <linux/orc_entry.h>
+
+/*
+ * For x86, use the appripriate name for the frame pointer in orc_entry.
+ */
+#define bp_offset	fp_offset
+#define bp_reg		fp_reg
 
 /*
  * The ORC_REG_* registers are base registers which are used to find other
@@ -39,34 +46,4 @@
 #define ORC_REG_SP_INDIRECT		9
 #define ORC_REG_MAX			15
 
-#ifndef __ASSEMBLY__
-#include <asm/byteorder.h>
-
-/*
- * This struct is more or less a vastly simplified version of the DWARF Call
- * Frame Information standard.  It contains only the necessary parts of DWARF
- * CFI, simplified for ease of access by the in-kernel unwinder.  It tells the
- * unwinder how to find the previous SP and BP (and sometimes entry regs) on
- * the stack for a given code address.  Each instance of the struct corresponds
- * to one or more code locations.
- */
-struct orc_entry {
-	s16		sp_offset;
-	s16		bp_offset;
-#if defined(__LITTLE_ENDIAN_BITFIELD)
-	unsigned	sp_reg:4;
-	unsigned	bp_reg:4;
-	unsigned	type:2;
-	unsigned	end:1;
-#elif defined(__BIG_ENDIAN_BITFIELD)
-	unsigned	bp_reg:4;
-	unsigned	sp_reg:4;
-	unsigned	unused:5;
-	unsigned	end:1;
-	unsigned	type:2;
-#endif
-} __packed;
-
-#endif /* __ASSEMBLY__ */
-
 #endif /* _ORC_TYPES_H */
diff --git a/include/linux/orc_entry.h b/include/linux/orc_entry.h
new file mode 100644
index 000000000000..3d49e3b9dabe
--- /dev/null
+++ b/include/linux/orc_entry.h
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2017 Josh Poimboeuf <jpoimboe@redhat.com>
+ */
+
+#ifndef _ORC_ENTRY_H
+#define _ORC_ENTRY_H
+
+#ifndef __ASSEMBLY__
+#include <asm/byteorder.h>
+
+/*
+ * This struct is more or less a vastly simplified version of the DWARF Call
+ * Frame Information standard.  It contains only the necessary parts of DWARF
+ * CFI, simplified for ease of access by the in-kernel unwinder.  It tells the
+ * unwinder how to find the previous SP and BP (and sometimes entry regs) on
+ * the stack for a given code address.  Each instance of the struct corresponds
+ * to one or more code locations.
+ */
+struct orc_entry {
+	s16		sp_offset;
+	s16		fp_offset;
+#if defined(__LITTLE_ENDIAN_BITFIELD)
+	unsigned	sp_reg:4;
+	unsigned	fp_reg:4;
+	unsigned	type:3;
+	unsigned	end:1;
+#elif defined(__BIG_ENDIAN_BITFIELD)
+	unsigned	fp_reg:4;
+	unsigned	sp_reg:4;
+	unsigned	unused:4;
+	unsigned	end:1;
+	unsigned	type:3;
+#endif
+} __packed;
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* _ORC_ENTRY_H */
diff --git a/tools/arch/x86/include/asm/orc_types.h b/tools/arch/x86/include/asm/orc_types.h
index 5a2baf28a1dc..851c9fb9f695 100644
--- a/tools/arch/x86/include/asm/orc_types.h
+++ b/tools/arch/x86/include/asm/orc_types.h
@@ -8,6 +8,13 @@
 
 #include <linux/types.h>
 #include <linux/compiler.h>
+#include <linux/orc_entry.h>
+
+/*
+ * For x86, use the appripriate name for the frame pointer in orc_entry.
+ */
+#define bp_offset	fp_offset
+#define bp_reg		fp_reg
 
 /*
  * The ORC_REG_* registers are base registers which are used to find other
@@ -39,34 +46,4 @@
 #define ORC_REG_SP_INDIRECT		9
 #define ORC_REG_MAX			15
 
-#ifndef __ASSEMBLY__
-#include <asm/byteorder.h>
-
-/*
- * This struct is more or less a vastly simplified version of the DWARF Call
- * Frame Information standard.  It contains only the necessary parts of DWARF
- * CFI, simplified for ease of access by the in-kernel unwinder.  It tells the
- * unwinder how to find the previous SP and BP (and sometimes entry regs) on
- * the stack for a given code address.  Each instance of the struct corresponds
- * to one or more code locations.
- */
-struct orc_entry {
-	s16		sp_offset;
-	s16		bp_offset;
-#if defined(__LITTLE_ENDIAN_BITFIELD)
-	unsigned	sp_reg:4;
-	unsigned	bp_reg:4;
-	unsigned	type:2;
-	unsigned	end:1;
-#elif defined(__BIG_ENDIAN_BITFIELD)
-	unsigned	bp_reg:4;
-	unsigned	sp_reg:4;
-	unsigned	unused:5;
-	unsigned	end:1;
-	unsigned	type:2;
-#endif
-} __packed;
-
-#endif /* __ASSEMBLY__ */
-
 #endif /* _ORC_TYPES_H */
diff --git a/tools/include/linux/orc_entry.h b/tools/include/linux/orc_entry.h
new file mode 100644
index 000000000000..3d49e3b9dabe
--- /dev/null
+++ b/tools/include/linux/orc_entry.h
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2017 Josh Poimboeuf <jpoimboe@redhat.com>
+ */
+
+#ifndef _ORC_ENTRY_H
+#define _ORC_ENTRY_H
+
+#ifndef __ASSEMBLY__
+#include <asm/byteorder.h>
+
+/*
+ * This struct is more or less a vastly simplified version of the DWARF Call
+ * Frame Information standard.  It contains only the necessary parts of DWARF
+ * CFI, simplified for ease of access by the in-kernel unwinder.  It tells the
+ * unwinder how to find the previous SP and BP (and sometimes entry regs) on
+ * the stack for a given code address.  Each instance of the struct corresponds
+ * to one or more code locations.
+ */
+struct orc_entry {
+	s16		sp_offset;
+	s16		fp_offset;
+#if defined(__LITTLE_ENDIAN_BITFIELD)
+	unsigned	sp_reg:4;
+	unsigned	fp_reg:4;
+	unsigned	type:3;
+	unsigned	end:1;
+#elif defined(__BIG_ENDIAN_BITFIELD)
+	unsigned	fp_reg:4;
+	unsigned	sp_reg:4;
+	unsigned	unused:4;
+	unsigned	end:1;
+	unsigned	type:3;
+#endif
+} __packed;
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* _ORC_ENTRY_H */
diff --git a/tools/objtool/orc_gen.c b/tools/objtool/orc_gen.c
index dd3c64af9db2..68c317daadbf 100644
--- a/tools/objtool/orc_gen.c
+++ b/tools/objtool/orc_gen.c
@@ -98,7 +98,7 @@ static int write_orc_entry(struct elf *elf, struct section *orc_sec,
 	orc = (struct orc_entry *)orc_sec->data->d_buf + idx;
 	memcpy(orc, o, sizeof(*orc));
 	orc->sp_offset = bswap_if_needed(orc->sp_offset);
-	orc->bp_offset = bswap_if_needed(orc->bp_offset);
+	orc->fp_offset = bswap_if_needed(orc->fp_offset);
 
 	/* populate reloc for ip */
 	if (elf_add_reloc_to_insn(elf, ip_sec, idx * sizeof(int), R_X86_64_PC32,
@@ -149,7 +149,7 @@ int orc_create(struct objtool_file *file)
 
 	struct orc_entry null = {
 		.sp_reg  = ORC_REG_UNDEFINED,
-		.bp_reg  = ORC_REG_UNDEFINED,
+		.fp_reg  = ORC_REG_UNDEFINED,
 		.type    = UNWIND_HINT_TYPE_CALL,
 	};
 
diff --git a/tools/objtool/sync-check.sh b/tools/objtool/sync-check.sh
index ee49b4e9e72c..ef1acb064605 100755
--- a/tools/objtool/sync-check.sh
+++ b/tools/objtool/sync-check.sh
@@ -18,6 +18,7 @@ arch/x86/include/asm/unwind_hints.h
 arch/x86/lib/x86-opcode-map.txt
 arch/x86/tools/gen-insn-attr-x86.awk
 include/linux/static_call_types.h
+include/linux/orc_entry.h
 "
 
 SYNC_CHECK_FILES='
-- 
2.25.1