linux-kernel - [PATCH 2/3] module: do not binary-search in __ksymtab

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Message-Id: <20220504194245.1088063-3-masahiroy@kernel.org>
Date:   Thu,  5 May 2022 04:42:44 +0900
From:   Masahiro Yamada <masahiroy@...nel.org>
To:     Luis Chamberlain <mcgrof@...nel.org>,
        linux-modules@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     Masahiro Yamada <masahiroy@...nel.org>
Subject: [PATCH 2/3] module: do not binary-search in __ksymtab_gpl if fsa->gplok is false

Currently, !fsa->gplok && syms->license == GPL_ONLY) is checked after
bsearch() succeeds.

It is meaningless to do the binary search in the GPL symbol table when
fsa->gplok is false because we know find_exported_symbol_in_section()
will fail anyway.

This check should be done before bsearch().

Signed-off-by: Masahiro Yamada <masahiroy@...nel.org>
---

 kernel/module.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/module.c b/kernel/module.c
index d57beb6b4eee..4380ceb825b9 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -448,8 +448,6 @@ static bool check_exported_symbol(const struct symsearch *syms,
 				  struct module *owner, unsigned int symnum,
 				  struct find_symbol_arg *fsa)
 {
-	if (!fsa->gplok && syms->license == GPL_ONLY)
-		return false;
 	fsa->owner = owner;
 	fsa->crc = symversion(syms->crcs, symnum);
 	fsa->sym = &syms->start[symnum];
@@ -497,6 +495,9 @@ static bool find_exported_symbol_in_section(const struct symsearch *syms,
 {
 	struct kernel_symbol *sym;
 
+	if (!fsa->gplok && syms->license == GPL_ONLY)
+		return false;
+
 	sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
 			sizeof(struct kernel_symbol), cmp_name);
 
-- 
2.32.0