Re: Bug: linking shared libraries on Cygwin results in undefined references to __stack_chck_guard for code compiled with -fstack-protector
Richard PALO <[email protected]>
| Newsgroups | gmane.comp.gnu.libtool.patches,gmane.comp.gnu.libtool.bugs |
|---|---|
| Message-ID | <[email protected]> |
Le 02/11/13 23:45, Richard PALO a écrit : > Le 02/06/10 05:24, Yaakov (Cygwin/X) a écrit : >> On Sat, 15 May 2010 09:07:49 +0200 >> Bart Van Assche <[email protected]> wrote: >>> This behavior has been observed with libtool version 2.2.6. >> >> Bug confirmed. When code is compiled with -fstack-protector{,-all}, >> GCC "emits extra code to check for buffer overflows, such as stack >> smashing attacks". This extra code uses symbols from libssp, and >> therefore (at least) Cygwin's GCC specs contain: >> >> *link_ssp: >> %{fstack-protector|fstack-protector-all:-lssp_nonshared -lssp} >> >> Therefore, when libtool fails to pass -fstack-protector{,-all} at link >> stage, the link fails. >> >> Patch attached. (Yes, I have a copyright assignment on file.) >> >> >> Yaakov >> Cygwin/X >> > > I've done some limited testing of this patch on a SunOS distro with > pkgsrc, and it certainly helps a number of cases since it is gcc that > generates the necessary '-lssp_nonshared -lssp' libs for linking (at > least in absence of '-nostdlib'). > > Please include in the upcoming version. > > > > I'd like to propose a slight modification this which, in addition, seems to get over the issue (at least on solaris) of c++ shared libraries linking '-nostdlib'. This could easily be adapted for other hosts using g++. Note, it is harmless if '-dumpspecs' or no spec with fstack-protector* is available. It appears there was no warm welcome in tossing the '-nostdlib' setup for g++ shared libraries for solaris, so this seems to be a reasonable workaround. -- Richard PALO
0001-workaround-for-nostdlib-with-fstack-protector-on-sol.patch
(text/x-patch, 1.9 KB)
From 5dfcf84c8243441f30a3c852791b8d46bc4d2c53 Mon Sep 17 00:00:00 2001 From: Richard PALO <[email protected]> Date: Thu, 24 Sep 2015 13:23:56 +0200 Subject: [PATCH] workaround for -nostdlib with -fstack-protector on solaris --- build-aux/ltmain.in | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) diff --git a/build-aux/ltmain.in b/build-aux/ltmain.in index 0c40da0..7a6356b 100644 --- a/build-aux/ltmain.in +++ b/build-aux/ltmain.in @@ -5364,8 +5364,7 @@ func_mode_link () # -stdlib=* select c++ std lib with clang -64|-mips[0-9]|-r[0-9][0-9]*|-xarch=*|-xtarget=*|+DA*|+DD*|-q*|-m*| \ -t[45]*|-txscale*|-p|-pg|--coverage|-fprofile-*|-F*|@*|-tp=*|--sysroot=*| \ - -O*|-g*|-flto*|-fwhopr*|-fuse-linker-plugin|-fstack-protector*|-stdlib=*| \ - -specs=*) + -O*|-g*|-flto*|-fwhopr*|-fuse-linker-plugin|-stdlib=*|-specs=*) func_quote_for_eval "$arg" arg=$func_quote_for_eval_result func_append compile_command " $arg" @@ -5374,6 +5373,25 @@ func_mode_link () continue ;; + -fstack-protector*) + func_quote_for_eval "$arg" + arg=$func_quote_for_eval_result + func_append compile_command " $arg" + func_append finalize_command " $arg" + func_append compiler_flags " $arg" + + # Explicitly add solaris ssp libs to postdeps to counter + # linking with g++ -nostdlib when supplied -fstack-protector* + test CXX = "$tagname" && { + case $host_os in + solaris*) + func_append postdeps " `$compile_command -dumpspecs 2>/dev/null | $SED -n '/fstack-protector/{s/^.*://;s/}$//;p;}'`" + ;; + esac + } + continue + ;; + -Z*) if test os2 = "`expr $host : '.*\(os2\)'`"; then # OS/2 uses -Zxxx to specify OS/2-specific options -- 2.5.2