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[Ada] don't overflow version string max length
- From: Alexandre Oliva <aoliva at redhat dot com>
- To: Eric Botcazou <ebotcazou at adacore dot com>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Tue, 30 Nov 2010 05:49:38 -0200
- Subject: [Ada] don't overflow version string max length
I got stage2 errors compiling ada/b_gnatb.c on x86_64-linux-gnu, because
it contained garbage at the end of __gnat_version.
It turned out that the full git version below exceeded the 64 bytes
reserved for the version string:
GNAT Version: 4.6.0 20101130 (experimental) [remotes/trunk revision a20ee7a:f6b2e47:00881f33e939f70ace98eaf6e9a65735dd378ba3]
The revision got corrupted as we attempted to copy more than 64 bytes
from the C string to the Ada string, writing past the end of the
allocated range, or some such (I didn't investigate the gory details of
when the garbage made to the version string printed by gnatbind)
This patch bumps up the maximum version length, to account for the
possibility of longer branch names, and truncates the copying at the
reserved length.
Regstrapping now (already past the earlier build error, and the version
string looks good). Ok to install?
for gcc/ada/ChangeLog
from Alexandre Oliva <aoliva@redhat.com>
* gnatvsn.adb (Gnat_Version_String): Don't overrun Ver_Len_Max.
* gnatvsn.ads (Ver_Len_Max): Bump up to 256.
* g-comver.adb (Ver_Len_Max): Likewise.
Index: gcc/ada/g-comver.adb
===================================================================
--- gcc/ada/g-comver.adb.orig 2010-11-30 05:07:59.264876475 -0200
+++ gcc/ada/g-comver.adb 2010-11-30 05:12:39.693675937 -0200
@@ -37,7 +37,7 @@
package body GNAT.Compiler_Version is
- Ver_Len_Max : constant := 64;
+ Ver_Len_Max : constant := 256;
-- This is logically a reference to Gnatvsn.Ver_Len_Max but we cannot
-- import this directly since run-time units cannot WITH compiler units.
Index: gcc/ada/gnatvsn.adb
===================================================================
--- gcc/ada/gnatvsn.adb.orig 2010-11-30 05:07:36.922608256 -0200
+++ gcc/ada/gnatvsn.adb 2010-11-30 05:10:54.833120167 -0200
@@ -74,6 +74,8 @@ package body Gnatvsn is
S (Pos + 1) := Version_String (Pos);
Pos := Pos + 1;
+
+ exit when Pos = Ver_Len_Max;
end loop;
return S (1 .. Pos);
Index: gcc/ada/gnatvsn.ads
===================================================================
--- gcc/ada/gnatvsn.ads.orig 2010-11-30 05:07:40.890478394 -0200
+++ gcc/ada/gnatvsn.ads 2010-11-30 05:12:25.830131950 -0200
@@ -70,7 +70,7 @@ package Gnatvsn is
-- Return the name of the Copyright holder to be displayed by the different
-- GNAT tools when switch --version is used.
- Ver_Len_Max : constant := 64;
+ Ver_Len_Max : constant := 256;
-- Longest possible length for Gnat_Version_String in this or any
-- other version of GNAT. This is used by the binder to establish
-- space to store any possible version string value for checks. This
--
Alexandre Oliva, freedom fighter http://FSFLA.org/~lxoliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/ FSF Latin America board member
Free Software Evangelist Red Hat Brazil Compiler Engineer