--- Begin Message ---
- To: submit@bugs.debian.org
- Subject: gcc-10: armhf: false positive when using -O2 and -Werror=format-truncation
- From: Julien Grall <julien@xen.org>
- Date: Wed, 23 Sep 2020 15:59:29 +0100
- Message-id: <db66179e-48d5-87c6-a28c-1a8e9063a6a1@xen.org>
X-Debbugs-CC: iwj@xenproject.org
X-Debbugs-CC: hans@knorrie.org
Package: gcc-10
Version: 10.2.0-9
Severity: important
Dear Maintainer,
There was an FTBFS for Xen when building using GCC 10 on armhf (see
bug #9689645 [1]).
After investigation, it looks a problem when with the optimizer in GCC
for armhf.
The issue was narrowed down to the following code:
42sh> cat test.c
#include <stdio.h>
#include <string.h>
#include <dirent.h>
char *tmp(struct dirent *dir_entry)
{
static char file_name[284];
if ( strlen(dir_entry->d_name) < 4 )
return NULL;
snprintf(file_name, sizeof(file_name), "%s",
dir_entry->d_name);
return file_name;
}
42sh> gcc -Wall -Werror -O2 -c test.c
test.c: In function 'tmp':
test.c:12:45: error: '%s' directive output may be truncated writing
between 4 and 2147483645 bytes into a region of size 284
[-Werror=format-truncation=]
12 | snprintf(file_name, sizeof(file_name), "%s",
| ^~
test.c:12:5: note: 'snprintf' output between 5 and 2147483646 bytes into
a destination of size 284
12 | snprintf(file_name, sizeof(file_name), "%s",
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
13 | dir_entry->d_name);
| ~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
Removing the length check will allow GCC to compile the object
sucessfully.
Would it be possible to investigate the root cause in GCC?
Cheers,
-- System Information:
Debian Release: bullseye/sid
APT prefers unstable
APT policy: (500, 'unstable')
Architecture: armhf (armv7l)
--
Julien Grall
--- End Message ---
--- Begin Message ---
Source: xen
Source-Version: 4.14.0+80-gd101b417b7-1
Done: Ian Jackson <ijackson@chiark.greenend.org.uk>
We believe that the bug you reported is fixed in the latest version of
xen, which is due to be installed in the Debian FTP archive.
A summary of the changes between this version and the previous one is
attached.
Thank you for reporting the bug, which will now be closed. If you
have further comments please address them to 970802@bugs.debian.org,
and the maintainer will reopen the bug report if appropriate.
Debian distribution maintenance software
pp.
Ian Jackson <ijackson@chiark.greenend.org.uk> (supplier of updated xen package)
(This message was generated automatically at their request; if you
believe that there is a problem with it please contact the archive
administrators by mailing ftpmaster@ftp-master.debian.org)
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256
Format: 1.8
Date: Tue, 24 Nov 2020 10:28:22 +0000
Source: xen
Architecture: source
Version: 4.14.0+80-gd101b417b7-1
Distribution: unstable
Urgency: medium
Maintainer: Debian Xen Team <pkg-xen-devel@lists.alioth.debian.org>
Changed-By: Ian Jackson <ijackson@chiark.greenend.org.uk>
Closes: 866380 938843 939560 961511 968965 970802
Changes:
xen (4.14.0+80-gd101b417b7-1) unstable; urgency=medium
.
* Re-upload to unstable for rebuild.
.
xen (4.14.0+80-gd101b417b7-1~exp2) experimental; urgency=medium
.
* Re-upload since apparently DMs aren't allowed NEW?
.
xen (4.14.0+80-gd101b417b7-1~exp1) experimental; urgency=medium
.
* Update to new upstream version 4.14.0+80-gd101b417b7, which also contains
security fixes for the following issues:
- Information leak via power sidechannel
XSA-351 (no CVE yet)
- x86 PV guest INVLPG-like flushes may leave stale TLB entries
XSA-286 (no CVE yet)
- unsafe AMD IOMMU page table updates
XSA-347 (no CVE yet)
- undue deferral of IOMMU TLB flushes
XSA-346 (no CVE yet)
- x86: Race condition in Xen mapping code
XSA-345 (no CVE yet)
- lack of preemption in evtchn_reset() / evtchn_destroy()
XSA-344 CVE-2020-25601
- races with evtchn_reset()
XSA-343 CVE-2020-25599
- out of bounds event channels available to 32-bit x86 domains
XSA-342 CVE-2020-25600
- Missing memory barriers when accessing/allocating an event channel
XSA-340 CVE-2020-25603
- x86 pv guest kernel DoS via SYSENTER
XSA-339 CVE-2020-25596
- once valid event channels may not turn invalid
XSA-338 CVE-2020-25597
- PCI passthrough code reading back hardware registers
XSA-337 CVE-2020-25595
- race when migrating timers between x86 HVM vCPU-s
XSA-336 CVE-2020-25604
- Missing unlock in XENMEM_acquire_resource error path
XSA-334 CVE-2020-25598
- x86 pv: Crash when handling guest access to MSR_MISC_ENABLE
XSA-333 CVE-2020-25602
* Updating to the most recent upstream stable-4.14 branch also fixes
additional compiling issues with gcc 10 that we were running into. These
were: upstream commit 5d45ecabe3c0 ("xen/arm64: force gcc 10+ to always
inline generic atomics helpers") to fix a FTBFS at mem_access.c and
upstream commit 0dfddb2116e3 ("tools/xenpmd: Fix gcc10 snprintf warning")
to fix a FTBFS on armhf. (Closes: #970802)
* Drop upstream commits d25cc3ec93eb ("libxl: workaround gcc 10.2
maybe-uninitialized warning") and fff1b7f50e75 ("libxl: fix
-Werror=stringop-truncation in libxl__prepare_sockaddr_un") from our patch
pile because these gcc 10 related fixes are in the upstream stable branch
now.
* Partially revert "debian/rules: Combine shared Make args" since it caused
a FTBFS on i386.
* Revert upstream commit a516bddbd3 ("tools/firmware/Makefile:
CONFIG_PV_SHIM: enable only on x86_64") and cherry-pick our previous
commits 0b898ccc2 ("tools/firmware/Makfile: Respect caller's
CONFIG_PV_SHIM") and a516bddbd3 ("tools/firmware/Makefile: CONFIG_PV_SHIM:
enable only on x86_64") again to work around a FTBFS where the shim would
not be built during the i386 package build.
* Now all FTBFS issues should be resolved, so we can do (Closes: #968965)
.
Packaging minor fixes and improvements:
* d/xen-utils-common.xen.init: Actually *really* include the change to
disable oom killer for xenstored. It inadvertently got lost in
4.14.0-1~exp1. (Closes: #961511)
.
Lintian related fixes:
* debian/changelog: fix a typo in the previous changelog entry
.
xen (4.14.0-1~exp1) experimental; urgency=medium
.
Significant changes:
* Update to new upstream version 4.14.0.
(Closes: #866380) about removal of broken xen-bugtool
* debian/{rules,control}: switch to python 3
(Closes: #938843) about python 2 removal in bullseye
* debian/control: Fix python dependency to use python3-dev:any and
libpython3-dev [Elliott Mitchell]
.
Changes related to upgrading to Xen 4.14:
* debian/control: adjust to 4.14
* debian/rules: remove install commands for pkgconfig files, since those
files are not present any more
* debian/: Follow fsimage -> xenfsimage renaming
* debian/xen-utils-V.*: Use @version@ instead of hardcoded version
* debian/control: add flex, bison
* debian/control: add libxenhypfs[1] [Ian Jackson]
* debian/libxenstore3.0.symbols: drop xprintf
(Closes: #968965) [Ian Jackson; also reported by Gianfranco Costamagna]
* d/scripts/xen-init-name, d/scripts/xen-init-list: rewrite these two
scripts, hugely simplify them and make them use python 3
* Pick upstream commits d25cc3ec93eb ("libxl: workaround gcc 10.2
maybe-uninitialized warning") and fff1b7f50e75 ("libxl: fix
-Werror=stringop-truncation in libxl__prepare_sockaddr_un") to fix gcc 10
FTBFS
* tools: don't build/ship xenmon, it can't work with python 3
.
Packaging minor fixes and improvements:
* debian/rules: Set DEB_BUILD_MAINT_OPTIONS in shell
(Closes: #939560) [Ian Jackson; report from Guillem Jover]
* debian/rules: Improve comment about hardening options
(Closes: #939560) [Ian Jackson; report from Guillem Jover]
* debian/rules: Drop redundant sequence numbers in dh_installinit
(Closes: #939560) [Ian Jackson; report from Guillem Jover]
* d/xen-utils-common.xen.init: add important notes to keep in mind when
changing this script, related to multi-version handling
* debian/control: cleanup Uploaders and add myself
* debian/control: s/libncurses5-dev/libncurses-dev/
* xen-utils-V scripts: remove update-alternatives command
* xen-utils-V.postinst.vsn-in: whitespace cosmetics
* d/xen-utils-common.xen.init: disable oom killer for xenstored
(Closes: #961511)
* debian/rules: Combine shared Make args [Elliott Mitchell]
.
Fixes and improvements for cross-compiling [Elliott Mitchell]:
* debian/rules: Add --host to tools configure target
* Pick upstream commit 69953e285638 ('tools: Partially revert
"Cross-compilation fixes."')
.
Lintian related fixes:
* debian/changelog: trim trailing whitespace. [Debian Janitor]
* debian/pycompat: remove obsolete file. [Debian Janitor]
* debian/rules: Avoid using $(PWD) variable. [Debian Janitor]
* debian/control: hardcode xen-utils-4.14 python3 dependency because
dh_python can't figure out how to add it
* debian/control: xen-doc: add ${misc:Depends}
* d/xen-hypervisor-V-F.lintian-overrides.vsn-in: fix override to use the
newer debug-suffix-not-dbg tag and correct the file path used so it
matches again
* debian/control: remove XS-Python-Version which is deprecated
* debian/control: drop autotools-dev build dependency because debhelper
already takes care of this
* d/xen-utils-V.lintian-overrides.vsn-in: fix rpath override because the
xenfsimage python .so filename changed from xenfsimage.so into
xenfsimage.cpython-38-x86_64-linux-gnu.so now, make it match again
* d/xen-utils-V.lintian-overrides.vsn-in: s/fsimage/xenfsimage/ which is a
left over change from the rename in some comment lines
* d/xen-utils-common.xen.init: use /run instead of /var/run because we don't
expect anyone on a pre-stretch system to build and use these packages
* debian/control: update Standards-Version to 4.5.0
Checksums-Sha1:
95021ac2b7ef913a3915a11ce714bcc00e2b4cbd 3898 xen_4.14.0+80-gd101b417b7-1.dsc
f0c1a3a553d211b43c8f3245fd4a13370f86edff 124708 xen_4.14.0+80-gd101b417b7-1.debian.tar.xz
Checksums-Sha256:
81a2e71d504b75ff93623e2d6e5d6ccddb8da094f7993a9f1b51d7a10d49fb9f 3898 xen_4.14.0+80-gd101b417b7-1.dsc
52e47e4aef25221446684622088d281f2dc1dbfa078a8c92818bf684b05e905a 124708 xen_4.14.0+80-gd101b417b7-1.debian.tar.xz
Files:
0c8f4ec3a14aa31b75fa5e387245af51 3898 admin optional xen_4.14.0+80-gd101b417b7-1.dsc
6e4e5d16dd2d2fef61369f30a0871e3c 124708 admin optional xen_4.14.0+80-gd101b417b7-1.debian.tar.xz
-----BEGIN PGP SIGNATURE-----
iQEzBAEBCAAdFiEEVZrkbC1rbTJl58uh4+M5I0i1DTkFAl+84KMACgkQ4+M5I0i1
DTlCzAf/RZKOvNx+gpriNWDbpRFV9z/JW24O3BIAOhaus1afkdN8nugfeY5G+9jG
5uHa5UVzBswWVY6fVoRpiiBg28bmhUgIhiCRciK7tB8DRxARwjPoyGyVl9oxLA9O
fCIzC0umkqhXKul0cnnVdrulPG7X/Rz9DeZzCgyqpeBcTtHKgeDDdnMn1A23uFF0
/7HYIPqrzdolNgqEbGaLxvK+tCOUZeXK4PUZkSZcI4q0FY95apCJNV4MTAAft+rb
AdctDPNFeK9dvm6oi3JFy/qd+tNJcMs3mRPgyDM3vM2SSINvbUd9IGox6uudliHD
XghSgq8mrYyfrhEMEgv/FkjPkKLi1g==
=0+qS
-----END PGP SIGNATURE-----
--- End Message ---