From 2d711186e1c134b069102e72d6d451942c931eb5 Mon Sep 17 00:00:00 2001
From: renoseven <dev@renoseven.net>
Date: Mon, 13 May 2024 21:27:13 +0800
Subject: [PATCH] upatch-diff: only check changed file symbols

1. sync compare results (SAME/NEW/CHANGED) to correlated objects
2. mark file changes by looking up symbol changes
3. check orignal object & debuginfo when file changes were detected
4. defer symbol check until after calculation changes

Signed-off-by: renoseven <dev@renoseven.net>
---
 upatch-diff/create-diff-object.c | 26 +++++++++++++--
 upatch-diff/elf-compare.c        | 57 ++++++++++++++++++--------------
 upatch-diff/running-elf.c        |  2 +-
 3 files changed, 56 insertions(+), 29 deletions(-)

diff --git a/upatch-diff/create-diff-object.c b/upatch-diff/create-diff-object.c
index 01c58b8..1a05869 100644
--- a/upatch-diff/create-diff-object.c
+++ b/upatch-diff/create-diff-object.c
@@ -481,12 +481,32 @@ static void find_debug_symbol(struct upatch_elf *uelf, struct running_elf *relf)
     struct symbol *file_sym = NULL;
 
     list_for_each_entry(file_sym, &uelf->symbols, list) {
-        if (file_sym->type == STT_FILE) {
+        if ((file_sym->type == STT_FILE) && (file_sym->status == CHANGED)) {
+            log_debug("file '%s' is CHANGED\n", file_sym->name);
             find_local_syms(uelf, relf, file_sym);
         }
     }
 }
 
+static void mark_file_symbols(struct upatch_elf *uelf)
+{
+    struct symbol *curr_sym = NULL;
+    struct symbol *file_sym = NULL;
+
+    list_for_each_entry(curr_sym, &uelf->symbols, list) {
+        if (curr_sym->type == STT_FILE) {
+            file_sym = curr_sym;
+            continue;
+        }
+        if ((file_sym == NULL) || (file_sym->status == CHANGED)) {
+            continue;
+        }
+        if (curr_sym->status == CHANGED) {
+            file_sym->status = CHANGED;
+        }
+    }
+}
+
 static void mark_grouped_sections(struct upatch_elf *uelf)
 {
     struct section *groupsec, *sec;
@@ -937,8 +957,6 @@ int main(int argc, char*argv[])
     detect_child_functions(&uelf_source);
     detect_child_functions(&uelf_patched);
 
-    find_debug_symbol(&uelf_source, &relf);
-
     mark_grouped_sections(&uelf_patched);
 
     replace_section_syms(&uelf_source);
@@ -952,6 +970,8 @@ int main(int argc, char*argv[])
     mark_ignored_sections(&uelf_patched);
 
     upatch_compare_correlated_elements(&uelf_patched);
+    mark_file_symbols(&uelf_source);
+    find_debug_symbol(&uelf_source, &relf);
 
     mark_ignored_functions_same(&uelf_patched);
     mark_ignored_sections_same(&uelf_patched);
diff --git a/upatch-diff/elf-compare.c b/upatch-diff/elf-compare.c
index 9b857b1..ef8dd23 100644
--- a/upatch-diff/elf-compare.c
+++ b/upatch-diff/elf-compare.c
@@ -336,38 +336,45 @@ static bool line_macro_change_only(struct upatch_elf *uelf, struct section *sec)
 	return false;
 }
 
+static inline void update_section_status(struct section *sec, enum status status)
+{
+	if (sec == NULL) {
+		return;
+	}
+	if (sec->twin != NULL) {
+		sec->twin->status = status;
+	}
+	if (is_rela_section(sec)) {
+		if ((sec->base != NULL) &&
+			(sec->base->sym != NULL)) {
+			sec->base->sym->status = status;
+		}
+	}
+	else {
+		if (sec->sym != NULL) {
+			sec->sym->status = status;
+		}
+	}
+}
+
 void upatch_compare_sections(struct upatch_elf *uelf)
 {
-	struct section *sec;
-	struct list_head *seclist = &uelf->sections;
+	struct section *sec = NULL;
 
-	/* compare all sections */
-	list_for_each_entry(sec, seclist, list) {
-		if (sec->twin)
-			compare_correlated_section(sec, sec->twin);
-		else
+	list_for_each_entry(sec, &uelf->sections, list) {
+		if (sec->twin == NULL) {
 			sec->status = NEW;
-	}
-
-	/* exclude WARN-only, might_sleep changes */
-	list_for_each_entry(sec, seclist, list) {
+		}
+		else {
+			compare_correlated_section(sec, sec->twin);
+		}
+		/* exclude WARN-only, might_sleep changes */
 		if (line_macro_change_only(uelf, sec)) {
 			log_debug("reverting macro / line number section %s status to SAME\n", sec->name);
 			sec->status = SAME;
 		}
-	}
-
-	/* sync symbol status */
-	list_for_each_entry(sec, seclist, list) {
-		if (is_rela_section(sec)) {
-            /* sync bundleable symbol for relocation section */
-			if (sec->base->sym && sec->base->sym->status != CHANGED)
-				sec->base->sym->status = sec->status;
-		} else {
-			struct symbol *sym = sec->sym;
-			if (sym && sym->status != CHANGED)
-				sym->status = sec->status;
-                /* TODO: handle child func */
-		}
+		/* sync status */
+		update_section_status(sec, sec->status);
+		update_section_status(sec->twin, sec->status);
 	}
 }
\ No newline at end of file
diff --git a/upatch-diff/running-elf.c b/upatch-diff/running-elf.c
index 3bb35e7..676880f 100644
--- a/upatch-diff/running-elf.c
+++ b/upatch-diff/running-elf.c
@@ -139,7 +139,7 @@ bool lookup_relf(struct running_elf *relf,
         result->sympos = sympos;
         result->global =
             ((symbol->bind == STB_GLOBAL) || (symbol->bind == STB_WEAK));
-        log_normal("found symbol '%s'\n", lookup_sym->name);
+        log_debug("found symbol '%s'\n", lookup_sym->name);
     }
 
     return (result->symbol != NULL);
-- 
2.34.1