Date: Thu, 24 Apr 2025 08:56:44 +0300 From: Andriy Gapon <avg@FreeBSD.org> To: Konstantin Belousov <kostikbel@gmail.com> Cc: FreeBSD Current <current@freebsd.org>, Mark Johnston <markj@FreeBSD.org> Subject: Re: RTLD_DEEPBIND question Message-ID: <59db8ace-770f-4f73-976f-411f6de0885a@FreeBSD.org> In-Reply-To: <e528f630-9d6e-4ec6-b7e6-30b5a978f5c8@freebsd.org> References: <0b3dda4e-53e4-40e5-9484-8b5ffb84e658@FreeBSD.org> <aALjHwFnFKChuAdR@kib.kiev.ua> <900c8521-559a-47b5-acaa-ae941f6852c4@freebsd.org> <fd12cce4-7e6b-4ab6-bced-b36e98c995ba@FreeBSD.org> <7c4e1682-d797-493c-8326-08d51dde3359@FreeBSD.org> <aAN69URjEJFuOLxR@kib.kiev.ua> <aAN9NH1IR-gZceP4@kib.kiev.ua> <e528f630-9d6e-4ec6-b7e6-30b5a978f5c8@freebsd.org>
index | next in thread | previous in thread | raw e-mail
On 23/04/2025 21:56, Andriy Gapon wrote: > BTW, I've been wondering how illumos avoids the problem even though they do not > use any special dlopen flags. > It turns out that they link almost all system shared libraries with -Bdirect > option (which is Solaris/illumos specific). > It's somewhat similar to, but different from, -Bsymbolic. > https://docs.oracle.com/cd/E23824_01/html/819-0690/aehzq.html#scrolltoc > https://docs.oracle.com/cd/E36784_01/html/E36857/gejfe.html Oh, and it looks like there is an even better explanation for illumos. There is a version map file for libdtrace which explicitly lists API functions and makes everything else local. https://github.com/illumos/illumos-gate/blob/master/usr/src/lib/libdtrace/common/mapfile-vers I wonder why we didn't do the same when porting. Maybe we should do that now? > I think that on FreeBSD we should use symbol visibility attributes or a symbol > map to hide (make local) symbols that are not expected to be interposed or have > a high chance to be interposed by accident. > > IMO, yyparse should definitely get that treatment. > > I think that approach would be better than magic rtld tricks. > Especially because the tricks do not work with the current rtld. > I'd rather make a change to libdtrace.so than to rtld. This, while not as nice as the illumos solution, fixes my specific issue: diff --git a/cddl/lib/libdtrace/Makefile b/cddl/lib/libdtrace/Makefile index d086fffb07bc..58054d129b49 100644 --- a/cddl/lib/libdtrace/Makefile +++ b/cddl/lib/libdtrace/Makefile @@ -146,7 +146,8 @@ CFLAGS+= -fsanitize=address -fsanitize=undefined LDFLAGS+= -fsanitize=address -fsanitize=undefined .endif -LIBADD= ctf elf proc pthread rtld_db xo +VERSION_MAP= ${.CURDIR}/Symbol.map +LIBADD= ctf elf proc pthread rtld_db xo CLEANFILES= dt_errtags.c dt_names.c diff --git a/cddl/lib/libdtrace/Symbol.map b/cddl/lib/libdtrace/Symbol.map new file mode 100644 index 000000000000..89ee9de65209 --- /dev/null +++ b/cddl/lib/libdtrace/Symbol.map @@ -0,0 +1,4 @@ +{ + local: + yy*; +}; -- Andriy Gaponhome | help
Want to link to this message? Use this
URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?59db8ace-770f-4f73-976f-411f6de0885a>