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From: "stefansf at linux dot ibm.com" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug sanitizer/99814] regexec fails with -fsanitize=address
Date: Tue, 30 Mar 2021 08:39:37 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D99814

--- Comment #2 from Stefan Schulze Frielinghaus <stefansf at linux dot ibm.=
com> ---
Breakpoint 4, __interception::InterceptFunction (name=3D0x3fffd61e8f2 "rege=
xec",
ver=3D0x3fffd61eb7e "GLIBC_2.3.4", ptr_to_real=3D0x3fffd677d08
<__interception::real_regexec>, func=3D16779728,=20
    wrapper=3D4398001883504) at
/devel/gcc-4/src/libsanitizer/interception/interception_linux.cpp:74
74        void *addr =3D GetFuncAddr(name, ver);

At the end of InterceptFunction we have:

(gdb) print addr
$1 =3D (void *) 0x3fffd2e9110 <__GI___regexec>

The address itself also LGTM, i.e., `readelf -s /lib64/libc.so.6 | grep
regexec` results in:
   279: 00000000000e9110   344 FUNC    GLOBAL DEFAULT   13 regexec@@GLIBC_2=
.3.4
...
 25156: 00000000000e9110   344 FUNC    LOCAL  DEFAULT   13 __GI___regexec

However, variables func and wrapper differ=20

(gdb) print func
$2 =3D 16779728
(gdb) print wrapper
$3 =3D 4398001883504

so we return false.=