linux-kernel - [PATCH v5 12/12] retpoline/modpost: Quieten MODVERSION retpoline build

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Message-Id: <1515239374-23361-13-git-send-email-dwmw@amazon.co.uk>
Date:   Sat,  6 Jan 2018 11:49:34 +0000
From:   David Woodhouse <dwmw@...zon.co.uk>
To:     Andi Kleen <ak@...ux.intel.com>
Cc:     Paul Turner <pjt@...gle.com>, LKML <linux-kernel@...r.kernel.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Greg Kroah-Hartman <gregkh@...ux-foundation.org>,
        Tim Chen <tim.c.chen@...ux.intel.com>,
        Dave Hansen <dave.hansen@...el.com>, tglx@...utronix.de,
        Kees Cook <keescook@...gle.com>,
        Rik van Riel <riel@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Andy Lutomirski <luto@...capital.net>,
        Jiri Kosina <jikos@...nel.org>, gnomes@...rguk.ukuu.org.uk
Subject: [PATCH v5 12/12] retpoline/modpost: Quieten MODVERSION retpoline build

From: Andi Kleen <ak@...ux.intel.com>

The internal retpoline thunks used by the compiler contain a dot.

They have to be exported, but modversions cannot handle them
it because they don't have a prototype due to the C incompatible
name (and it doesn't support asm("..."))

This leads to lots of warnings from modpost with a retpoline
build with MODVERSIONS enabled. The actual symbols load fine,
they just don't get versioned. That's not a problem here
because we don't expect them to change ever.

Quieten the respective warning messages in modpost for any
symbols containing a dot.

Signed-off-by: Andi Kleen <ak@...ux.intel.com>
Signed-off-by: David Woodhouse <dwmw@...zon.co.uk>
---
 scripts/mod/modpost.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 98314b4..e564da2 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -693,7 +693,9 @@ static void handle_modversions(struct module *mod, struct elf_info *info,
 #endif
 		if (is_crc) {
 			const char *e = is_vmlinux(mod->name) ?"":".ko";
-			warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n", symname + strlen(CRC_PFX), mod->name, e);
+			const char *name = symname + strlen(CRC_PFX);
+			if (!strchr(name, '.'))
+				warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n", name, mod->name, e);
 		}
 		mod->unres = alloc_symbol(symname,
 					  ELF_ST_BIND(sym->st_info) == STB_WEAK,
@@ -2212,7 +2214,7 @@ static int add_versions(struct buffer *b, struct module *mod)
 	for (s = mod->unres; s; s = s->next) {
 		if (!s->module)
 			continue;
-		if (!s->crc_valid) {
+		if (!s->crc_valid && !strchr(s->name, '.')) {
 			warn("\"%s\" [%s.ko] has no CRC!\n",
 				s->name, mod->name);
 			continue;
-- 
2.7.4