[PATCH v4 04/36] scripts/kallysms: Always include __start and __stop symbols

Suren Baghdasaryan
2024-02-21T19:41:06Z

From: Kent Overstreet <kent.overstreet@linux.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@linux.dev>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Kees Cook <keescook@chromium.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