linux-kernel - [RFC PATCH 04/30] scripts/kallysms: Always include __start and _

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Message-ID: <20220830214919.53220-5-surenb@google.com>
Date:   Tue, 30 Aug 2022 14:48:53 -0700
From:   Suren Baghdasaryan <surenb@...gle.com>
To:     akpm@...ux-foundation.org
Cc:     kent.overstreet@...ux.dev, mhocko@...e.com, vbabka@...e.cz,
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Subject: [RFC PATCH 04/30] scripts/kallysms: Always include __start and __stop symbols

From: Kent Overstreet <kent.overstreet@...ux.dev>

These symbols are used to denote section boundaries: by always including
them we can unify loading sections from modules with loading built-in
sections, which leads to some significant cleanup.

Signed-off-by: Kent Overstreet <kent.overstreet@...ux.dev>
---
 scripts/kallsyms.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index f18e6dfc68c5..3d51639a595d 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -263,6 +263,11 @@ static int symbol_in_range(const struct sym_entry *s,
 	return 0;
 }
 
+static bool string_starts_with(const char *s, const char *prefix)
+{
+	return strncmp(s, prefix, strlen(prefix)) == 0;
+}
+
 static int symbol_valid(const struct sym_entry *s)
 {
 	const char *name = sym_name(s);
@@ -270,6 +275,14 @@ static int symbol_valid(const struct sym_entry *s)
 	/* if --all-symbols is not specified, then symbols outside the text
 	 * and inittext sections are discarded */
 	if (!all_symbols) {
+		/*
+		 * Symbols starting with __start and __stop are used to denote
+		 * section boundaries, and should always be included:
+		 */
+		if (string_starts_with(name, "__start_") ||
+		    string_starts_with(name, "__stop_"))
+			return 1;
+
 		if (symbol_in_range(s, text_ranges,
 				    ARRAY_SIZE(text_ranges)) == 0)
 			return 0;
-- 
2.37.2.672.g94769d06f0-goog