linux-kernel - [PATCH v4 04/36] scripts/kallysms: Always include __start and _

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Message-ID: <20240221194052.927623-5-surenb@google.com>
Date: Wed, 21 Feb 2024 11:40:17 -0800
From: Suren Baghdasaryan <surenb@...gle.com>
To: akpm@...ux-foundation.org
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Subject: [PATCH v4 04/36] 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>
Signed-off-by: Suren Baghdasaryan <surenb@...gle.com>
Reviewed-by: Kees Cook <keescook@...omium.org>
---
 scripts/kallsyms.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index 653b92f6d4c8..47978efe4797 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -204,6 +204,11 @@ 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);
@@ -211,6 +216,14 @@ 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;
-- 
2.44.0.rc0.258.g7320e95886-goog