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From:   Julien Thierry <jthierry@redhat.com>
To:     linux-kernel@vger.kernel.org
Cc:     jpoimboe@redhat.com, peterz@infradead.org, mhelsley@vmware.com,
        Julien Thierry <jthierry@redhat.com>
Subject: [PATCH 4/4] objtool: orc_gen: Move orc_entry out of instruction structure
Date:   Thu,  4 Jun 2020 17:39:38 +0100
Message-Id: <20200604163938.21660-5-jthierry@redhat.com>
In-Reply-To: <20200604163938.21660-1-jthierry@redhat.com>
References: <20200604163938.21660-1-jthierry@redhat.com>
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One orc_entry is associated with each instruction in the object file,
but having the orc_entry contained by the instruction structure forces
architectures not implementing the orc subcommands to provide a dummy
definition of the orc_entry.

Avoid that by having orc_entries in a separate list, part of the
objtool_file.

Signed-off-by: Julien Thierry <jthierry@redhat.com>
---
 tools/objtool/check.h   |  1 -
 tools/objtool/objtool.c |  1 +
 tools/objtool/objtool.h |  1 +
 tools/objtool/orc_gen.c | 83 +++++++++++++++++++++++------------------
 4 files changed, 49 insertions(+), 37 deletions(-)

diff --git a/tools/objtool/check.h b/tools/objtool/check.h
index 906b5210f7ca..49f9a5cc4228 100644
--- a/tools/objtool/check.h
+++ b/tools/objtool/check.h
@@ -42,7 +42,6 @@ struct instruction {
 	struct symbol *func;
 	struct list_head stack_ops;
 	struct cfi_state cfi;
-	struct orc_entry orc;
 };
 
 struct instruction *find_insn(struct objtool_file *file,
diff --git a/tools/objtool/objtool.c b/tools/objtool/objtool.c
index 71c4122cf491..4b2e8013edb8 100644
--- a/tools/objtool/objtool.c
+++ b/tools/objtool/objtool.c
@@ -61,6 +61,7 @@ struct objtool_file *objtool_setup_file(const char *_objname, bool writable)
 
 	INIT_LIST_HEAD(&file.insn_list);
 	hash_init(file.insn_hash);
+	INIT_LIST_HEAD(&file.orc_data_list);
 	file.c_file = find_section_by_name(file.elf, ".comment");
 	file.ignore_unreachables = no_unreachable;
 	file.hints = false;
diff --git a/tools/objtool/objtool.h b/tools/objtool/objtool.h
index be526f3d294d..e782c4206cb2 100644
--- a/tools/objtool/objtool.h
+++ b/tools/objtool/objtool.h
@@ -16,6 +16,7 @@ struct objtool_file {
 	struct elf *elf;
 	struct list_head insn_list;
 	DECLARE_HASHTABLE(insn_hash, 20);
+	struct list_head orc_data_list;
 	bool ignore_unreachables, c_file, hints, rodata;
 };
 
diff --git a/tools/objtool/orc_gen.c b/tools/objtool/orc_gen.c
index e74578640705..b8d199682530 100644
--- a/tools/objtool/orc_gen.c
+++ b/tools/objtool/orc_gen.c
@@ -9,14 +9,32 @@
 #include "check.h"
 #include "warn.h"
 
+struct orc_data {
+	struct list_head list;
+	struct instruction *insn;
+	struct orc_entry orc;
+};
+
 int create_orc(struct objtool_file *file)
 {
 	struct instruction *insn;
 
 	for_each_insn(file, insn) {
-		struct orc_entry *orc = &insn->orc;
 		struct cfi_reg *cfa = &insn->cfi.cfa;
 		struct cfi_reg *bp = &insn->cfi.regs[CFI_BP];
+		struct orc_entry *orc;
+		struct orc_data *od;
+
+		if (!insn->sec->text)
+			continue;
+
+		od = calloc(1, sizeof(*od));
+		if (!od)
+			return -1;
+		od->insn = insn;
+		list_add_tail(&od->list, &file->orc_data_list);
+
+		orc = &od->orc;
 
 		if (!insn->sec->text)
 			continue;
@@ -139,7 +157,7 @@ static int create_orc_entry(struct elf *elf, struct section *u_sec, struct secti
 
 int create_orc_sections(struct objtool_file *file)
 {
-	struct instruction *insn, *prev_insn;
+	struct orc_data *od, *prev_od;
 	struct section *sec, *u_sec, *ip_relasec;
 	unsigned int idx;
 
@@ -157,23 +175,21 @@ int create_orc_sections(struct objtool_file *file)
 
 	/* count the number of needed orcs */
 	idx = 0;
-	for_each_sec(file, sec) {
-		if (!sec->text)
-			continue;
-
-		prev_insn = NULL;
-		sec_for_each_insn(file, sec, insn) {
-			if (!prev_insn ||
-			    memcmp(&insn->orc, &prev_insn->orc,
-				   sizeof(struct orc_entry))) {
-				idx++;
-			}
-			prev_insn = insn;
+	prev_od = NULL;
+	list_for_each_entry(od, &file->orc_data_list, list) {
+		if (!prev_od ||
+		    memcmp(&od->orc, &prev_od->orc, sizeof(struct orc_entry))) {
+			idx++;
 		}
 
+		prev_od = od;
+
 		/* section terminator */
-		if (prev_insn)
+		if (list_is_last(&od->insn->list, &file->insn_list) ||
+		    list_next_entry(od->insn, list)->sec != od->insn->sec) {
+			prev_od = NULL;
 			idx++;
+		}
 	}
 	if (!idx)
 		return -1;
@@ -194,33 +210,28 @@ int create_orc_sections(struct objtool_file *file)
 
 	/* populate sections */
 	idx = 0;
-	for_each_sec(file, sec) {
-		if (!sec->text)
-			continue;
-
-		prev_insn = NULL;
-		sec_for_each_insn(file, sec, insn) {
-			if (!prev_insn || memcmp(&insn->orc, &prev_insn->orc,
-						 sizeof(struct orc_entry))) {
-
-				if (create_orc_entry(file->elf, u_sec, ip_relasec, idx,
-						     insn->sec, insn->offset,
-						     &insn->orc))
-					return -1;
-
-				idx++;
-			}
-			prev_insn = insn;
+	prev_od = NULL;
+	list_for_each_entry(od, &file->orc_data_list, list) {
+		if (!prev_od ||
+		    memcmp(&od->orc, &prev_od->orc, sizeof(struct orc_entry))) {
+			if (create_orc_entry(file->elf, u_sec, ip_relasec, idx,
+					     od->insn->sec, od->insn->offset,
+					     &od->orc))
+				return -1;
+			idx++;
 		}
 
+		prev_od = od;
+
 		/* section terminator */
-		if (prev_insn) {
+		if (list_is_last(&od->insn->list, &file->insn_list) ||
+		    list_next_entry(od->insn, list)->sec != od->insn->sec) {
 			if (create_orc_entry(file->elf, u_sec, ip_relasec, idx,
-					     prev_insn->sec,
-					     prev_insn->offset + prev_insn->len,
+					     prev_od->insn->sec,
+					     prev_od->insn->offset + prev_od->insn->len,
 					     &empty))
 				return -1;
-
+			prev_od = NULL;
 			idx++;
 		}
 	}
-- 
2.21.1