public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
* [Bug libgcc/99236] New: Undefined behaviour in libgcc
@ 2021-02-24 7:15 zeccav at gmail dot com
2021-02-24 12:34 ` [Bug libgcc/99236] " jakub at gcc dot gnu.org
` (4 more replies)
0 siblings, 5 replies; 6+ messages in thread
From: zeccav at gmail dot com @ 2021-02-24 7:15 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99236
Bug ID: 99236
Summary: Undefined behaviour in libgcc
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libgcc
Assignee: unassigned at gcc dot gnu.org
Reporter: zeccav at gmail dot com
Target Milestone: ---
! must be compiled and run
! It does not need sanitized compiler, but
! must be loaded with sanitized version of libgcc_s.so.1
! ldd a.out -> libgcc_s.so.1 =>
/home/vitti/local/gcc-150221-undefined/lib64/libgcc_s.so.1
!../../../gcc-150221/libgcc/libgcc2.c:1837:31: runtime error: negation of
-2147483648 cannot be represented in type 'int'; cast to an unsigned type to
negate this value to itself
! libgcc2.c:1837 -> "unsigned int n = m < 0 ? -m : m;"
a = 3.0
b = a**(-2147483647_4-1_4)
end
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug libgcc/99236] Undefined behaviour in libgcc
2021-02-24 7:15 [Bug libgcc/99236] New: Undefined behaviour in libgcc zeccav at gmail dot com
@ 2021-02-24 12:34 ` jakub at gcc dot gnu.org
2021-02-24 12:37 ` jakub at gcc dot gnu.org
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: jakub at gcc dot gnu.org @ 2021-02-24 12:34 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99236
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed| |2021-02-24
Assignee|unassigned at gcc dot gnu.org |jakub at gcc dot gnu.org
Status|UNCONFIRMED |ASSIGNED
Ever confirmed|0 |1
CC| |jakub at gcc dot gnu.org
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug libgcc/99236] Undefined behaviour in libgcc
2021-02-24 7:15 [Bug libgcc/99236] New: Undefined behaviour in libgcc zeccav at gmail dot com
2021-02-24 12:34 ` [Bug libgcc/99236] " jakub at gcc dot gnu.org
@ 2021-02-24 12:37 ` jakub at gcc dot gnu.org
2021-02-24 13:52 ` zeccav at gmail dot com
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: jakub at gcc dot gnu.org @ 2021-02-24 12:37 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99236
--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 50246
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50246&action=edit
gcc11-pr99236.patch
Untested fix.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug libgcc/99236] Undefined behaviour in libgcc
2021-02-24 7:15 [Bug libgcc/99236] New: Undefined behaviour in libgcc zeccav at gmail dot com
2021-02-24 12:34 ` [Bug libgcc/99236] " jakub at gcc dot gnu.org
2021-02-24 12:37 ` jakub at gcc dot gnu.org
@ 2021-02-24 13:52 ` zeccav at gmail dot com
2021-02-24 19:09 ` cvs-commit at gcc dot gnu.org
2021-02-24 19:16 ` jakub at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: zeccav at gmail dot com @ 2021-02-24 13:52 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99236
--- Comment #2 from Vittorio Zecca <zeccav at gmail dot com> ---
After patching libgcc2.c the test case runs fine without sanitizer messages.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug libgcc/99236] Undefined behaviour in libgcc
2021-02-24 7:15 [Bug libgcc/99236] New: Undefined behaviour in libgcc zeccav at gmail dot com
` (2 preceding siblings ...)
2021-02-24 13:52 ` zeccav at gmail dot com
@ 2021-02-24 19:09 ` cvs-commit at gcc dot gnu.org
2021-02-24 19:16 ` jakub at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: cvs-commit at gcc dot gnu.org @ 2021-02-24 19:09 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99236
--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jakub Jelinek <jakub@gcc.gnu.org>:
https://gcc.gnu.org/g:35da095d7e0614235cb0e241685c5e1a240dc882
commit r11-7374-g35da095d7e0614235cb0e241685c5e1a240dc882
Author: Jakub Jelinek <jakub@redhat.com>
Date: Wed Feb 24 20:07:38 2021 +0100
libgcc: Avoid signed negation overflow in __powi?f2 [PR99236]
When these functions are called with integer minimum, there is UB on the
libgcc
side. Fixed in the obvious way, the code in the end wants ABSU_EXPR
behavior.
2021-02-24 Jakub Jelinek <jakub@redhat.com>
PR libgcc/99236
* libgcc2.c (__powisf2, __powidf2, __powitf2, __powixf2): Perform
negation of m in unsigned type.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug libgcc/99236] Undefined behaviour in libgcc
2021-02-24 7:15 [Bug libgcc/99236] New: Undefined behaviour in libgcc zeccav at gmail dot com
` (3 preceding siblings ...)
2021-02-24 19:09 ` cvs-commit at gcc dot gnu.org
@ 2021-02-24 19:16 ` jakub at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: jakub at gcc dot gnu.org @ 2021-02-24 19:16 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99236
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Resolution|--- |FIXED
Status|ASSIGNED |RESOLVED
--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Fixed in GCC 11, IMHO not worth backporting.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2021-02-24 19:16 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-02-24 7:15 [Bug libgcc/99236] New: Undefined behaviour in libgcc zeccav at gmail dot com
2021-02-24 12:34 ` [Bug libgcc/99236] " jakub at gcc dot gnu.org
2021-02-24 12:37 ` jakub at gcc dot gnu.org
2021-02-24 13:52 ` zeccav at gmail dot com
2021-02-24 19:09 ` cvs-commit at gcc dot gnu.org
2021-02-24 19:16 ` jakub at gcc dot gnu.org
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).