https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115127
Bug ID: 115127
Summary: [12/13/14 Regression] passing zero to __builtin_ctz()
check missing
Product: gcc
Version: 12.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: sanitizer
Assignee: unassigned at gcc dot gnu.org
Reporter: bic60176 at gmail dot com
CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org,
jakub at gcc dot gnu.org, kcc at gcc dot gnu.org
Target Milestone: ---
Created attachment 58220
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=58220&action=edit
test case
OS: Ubuntu 22.04.3 LTS
We found that UBSAN missed checking if zero is passed to __builtin_ctz() when
compiling with gcc-12.3.0, gcc-13.2.0, gcc-14.1.0.
$ ../compiler-builds/gcc-12.3.0_build/bin/gcc -fsanitize=undefined -g -lgcc_s
-I/home/csmith/include/csmith-2.3.0 testcase.c -o exec
$ timeout 1s ./exec 2>exec.err
$ cat exec.err
$ ../compiler-builds/gcc-11.4.0_build/bin/gcc -fsanitize=undefined -g -lgcc_s
-I/home/csmith/include/csmith-2.3.0 testcase.c -o exec
$ timeout 1s ./exec 2>exec.err
$ cat exec.err
test1_176.c:202:83: runtime error: passing zero to ctz(), which is not a valid
argument test1_176.c:202: runtime error: passing zero to ctz(), which is not a
valid argument test1_176.c:202: runtime error: passing zero to ctz(), which is
not a valid argument test1_176.c:202: runtime error: passing zero to ctz(),
which is not a valid argument test1_176.c:202: runtime error: passing zero to
ctz(), which is not a valid argument test1_176.c:202: runtime error: passing
zero to ctz(), which is not a valid argument
