linux-kernel - [PATCH, ppc64] improve dedotify()

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-Id: <4787415E.76E4.0078.0@novell.com>
Date:	Fri, 11 Jan 2008 09:13:50 +0000
From:	"Jan Beulich" <jbeulich@...ell.com>
To:	<paulus@...ba.org>
Cc:	<linuxppc-dev@...abs.org>, <linux-kernel@...r.kernel.org>
Subject: [PATCH, ppc64] improve dedotify()

This completely untested patch is intended to be a suggestion only:
Code inspection for an entirely different purpose made me stumble
across this, and I think that modifying the string table of an ELF
object is a bad idea, since there's nothing disallowing a linker to
merge strings inside the table, which would result in this code
possibly, but unintentionally screwing up other symbol names.
Besides that, the presented alternative is both smaller and faster.

Signed-off-by: Jan Beulich <jbeulich@...ell.com>

---
 arch/powerpc/kernel/module_64.c |   10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

--- linux-2.6.24-rc7/arch/powerpc/kernel/module_64.c	2007-02-04 19:44:54.000000000 +0100
+++ 2.6.24-rc7-ppc64-dedotify/arch/powerpc/kernel/module_64.c	2008-01-08 13:32:33.000000000 +0100
@@ -154,16 +154,14 @@ static void dedotify_versions(struct mod
 }
 
 /* Undefined symbols which refer to .funcname, hack to funcname */
-static void dedotify(Elf64_Sym *syms, unsigned int numsyms, char *strtab)
+static void dedotify(Elf64_Sym *syms, unsigned int numsyms, const char *strtab)
 {
 	unsigned int i;
 
 	for (i = 1; i < numsyms; i++) {
-		if (syms[i].st_shndx == SHN_UNDEF) {
-			char *name = strtab + syms[i].st_name;
-			if (name[0] == '.')
-				memmove(name, name+1, strlen(name));
-		}
+		if (syms[i].st_shndx == SHN_UNDEF
+		    && strtab[syms[i].st_name] == '.')
+			syms[i].st_name++;
 	}
 }
 



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/