Fix un undefined C behavior in NULL pointer arithmetics

This commit is contained in:
Petr Písař 2019-01-15 09:01:30 +01:00
parent 8cee2a9175
commit 7f49d3b6d7
2 changed files with 90 additions and 0 deletions

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@ -0,0 +1,83 @@
From 8c165a32b7cc4f2a147a37c920a96f1b09b2386d Mon Sep 17 00:00:00 2001
From: Karl Williamson <khw@cpan.org>
Date: Sun, 30 Dec 2018 21:29:07 -0700
Subject: [PATCH] regen/warnings.pl: Fix undefined C behavior
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
This fixes compiler warnings "performing pointer arithmetic on a null
pointer has undefined behavior"
There are several ways to fix this. This one was suggested by
Tomasz Konojacki++. Instead of trying to point to address 1 and 2, two
variables are created, and we point to them. const is cast away.
Signed-off-by: Petr Písař <ppisar@redhat.com>
---
globvar.sym | 2 ++
perl.h | 5 +++++
regen/warnings.pl | 4 ++--
warnings.h | 4 ++--
4 files changed, 11 insertions(+), 4 deletions(-)
diff --git a/globvar.sym b/globvar.sym
index 6fb387ca0a..476f4ca095 100644
--- a/globvar.sym
+++ b/globvar.sym
@@ -83,4 +83,6 @@ PL_warn_nl
PL_warn_nosemi
PL_warn_reserved
PL_warn_uninit
+PL_WARN_ALL
+PL_WARN_NONE
PL_watch_pvx
diff --git a/perl.h b/perl.h
index 43b42a8aa5..dd66b120af 100644
--- a/perl.h
+++ b/perl.h
@@ -4454,6 +4454,11 @@ EXTCONST char PL_Zero[]
EXTCONST char PL_hexdigit[]
INIT("0123456789abcdef0123456789ABCDEF");
+EXTCONST STRLEN PL_WARN_ALL
+ INIT(0);
+EXTCONST STRLEN PL_WARN_NONE
+ INIT(0);
+
/* This is constant on most architectures, a global on OS/2 */
#ifndef OS2
EXTCONST char PL_sh_path[]
diff --git a/regen/warnings.pl b/regen/warnings.pl
index 9c01e6762f..d244160b3e 100644
--- a/regen/warnings.pl
+++ b/regen/warnings.pl
@@ -322,8 +322,8 @@ my ($index, $warn_size);
#define G_WARN_ALL_MASK (G_WARN_ALL_ON|G_WARN_ALL_OFF)
#define pWARN_STD NULL
-#define pWARN_ALL (((STRLEN*)0)+1) /* use warnings 'all' */
-#define pWARN_NONE (((STRLEN*)0)+2) /* no warnings 'all' */
+#define pWARN_ALL (STRLEN *) &PL_WARN_ALL /* use warnings 'all' */
+#define pWARN_NONE (STRLEN *) &PL_WARN_NONE /* no warnings 'all' */
#define specialWARN(x) ((x) == pWARN_STD || (x) == pWARN_ALL || \
(x) == pWARN_NONE)
diff --git a/warnings.h b/warnings.h
index e0c12ed403..58f52272de 100644
--- a/warnings.h
+++ b/warnings.h
@@ -18,8 +18,8 @@
#define G_WARN_ALL_MASK (G_WARN_ALL_ON|G_WARN_ALL_OFF)
#define pWARN_STD NULL
-#define pWARN_ALL (((STRLEN*)0)+1) /* use warnings 'all' */
-#define pWARN_NONE (((STRLEN*)0)+2) /* no warnings 'all' */
+#define pWARN_ALL (STRLEN *) &PL_WARN_ALL /* use warnings 'all' */
+#define pWARN_NONE (STRLEN *) &PL_WARN_NONE /* no warnings 'all' */
#define specialWARN(x) ((x) == pWARN_STD || (x) == pWARN_ALL || \
(x) == pWARN_NONE)
--
2.17.2

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@ -235,6 +235,10 @@ Patch46: perl-5.29.6-First-eof-should-return-true.patch
# Fix a crash when compiling a malformed form, RT#132158, in upstream after 5.29.6 # Fix a crash when compiling a malformed form, RT#132158, in upstream after 5.29.6
Patch47: perl-5.29.6-perl-132158-abort-compilation-if-we-see-an-error-com.patch Patch47: perl-5.29.6-perl-132158-abort-compilation-if-we-see-an-error-com.patch
# Fix un undefined C behavior in NULL pointer arithmetics, RT#133223,
# in upstream after 5.29.6
Patch48: perl-5.29.6-regen-warnings.pl-Fix-undefined-C-behavior.patch
# Link XS modules to libperl.so with EU::CBuilder on Linux, bug #960048 # Link XS modules to libperl.so with EU::CBuilder on Linux, bug #960048
Patch200: perl-5.16.3-Link-XS-modules-to-libperl.so-with-EU-CBuilder-on-Li.patch Patch200: perl-5.16.3-Link-XS-modules-to-libperl.so-with-EU-CBuilder-on-Li.patch
@ -2836,6 +2840,7 @@ Perl extension for Version Objects
%patch45 -p1 %patch45 -p1
%patch46 -p1 %patch46 -p1
%patch47 -p1 %patch47 -p1
%patch48 -p1
%patch200 -p1 %patch200 -p1
%patch201 -p1 %patch201 -p1
@ -2877,6 +2882,7 @@ perl -x patchlevel.h \
'Fedora Patch44: Fix reporting a line number for non-terminated prototypes (RT#133524)' \ 'Fedora Patch44: Fix reporting a line number for non-terminated prototypes (RT#133524)' \
'Fedora Patch45: Fix first eof() return value (RT#133721)' \ 'Fedora Patch45: Fix first eof() return value (RT#133721)' \
'Fedora Patch47: Fix a crash when compiling a malformed form (RT#132158)' \ 'Fedora Patch47: Fix a crash when compiling a malformed form (RT#132158)' \
'Fedora Patch48: Fix un undefined C behavior in NULL pointer arithmetics (RT#133223)' \
'Fedora Patch200: Link XS modules to libperl.so with EU::CBuilder on Linux' \ 'Fedora Patch200: Link XS modules to libperl.so with EU::CBuilder on Linux' \
'Fedora Patch201: Link XS modules to libperl.so with EU::MM on Linux' \ 'Fedora Patch201: Link XS modules to libperl.so with EU::MM on Linux' \
%{nil} %{nil}
@ -5171,6 +5177,7 @@ popd
- Fix reporting a line number for non-terminated prototypes (RT#133524) - Fix reporting a line number for non-terminated prototypes (RT#133524)
- Fix first eof() return value (RT#133721) - Fix first eof() return value (RT#133721)
- Fix a crash when compiling a malformed form (RT#132158) - Fix a crash when compiling a malformed form (RT#132158)
- Fix un undefined C behavior in NULL pointer arithmetics (RT#133223)
* Mon Jan 14 2019 Björn Esser <besser82@fedoraproject.org> - 4:5.28.1-429 * Mon Jan 14 2019 Björn Esser <besser82@fedoraproject.org> - 4:5.28.1-429
- Rebuilt for libcrypt.so.2 (#1666033) - Rebuilt for libcrypt.so.2 (#1666033)