| Message ID | 1493319051-25795-1-git-send-email-blomqvist.janne@gmail.com |
|---|---|
| State | New |
| Headers | show |
Hi! On Thu, 27 Apr 2017 21:50:51 +0300, Janne Blomqvist <blomqvist.janne@gmail.com> wrote: > [...], retain the support for __secure_getenv but call it only via a > weak reference. > > Regtested on x86_64-pc-linux-gnu, Ok for trunk, 7.x when it reopens, > 6, 5? Hmm, how has this been tested? Because: > --- a/libgfortran/runtime/environ.c > +++ b/libgfortran/runtime/environ.c > #ifdef FALLBACK_SECURE_GETENV > + > +#if SUPPORTS_WEAKREF && defined(HAVE___SECURE_GETENV) > +static char* weak_secure_getenv (const char*) > + __attribute__((__weakref__("__secure_gettime"))); > +#endif "gettime" vs. "getenv"? ;-) Grüße Thomas
On Fri, May 12, 2017 at 10:23 AM, Thomas Schwinge <thomas@codesourcery.com> wrote: > Hi! > > On Thu, 27 Apr 2017 21:50:51 +0300, Janne Blomqvist <blomqvist.janne@gmail.com> wrote: >> [...], retain the support for __secure_getenv but call it only via a >> weak reference. >> >> Regtested on x86_64-pc-linux-gnu, Ok for trunk, 7.x when it reopens, >> 6, 5? > > Hmm, how has this been tested? Because: > >> --- a/libgfortran/runtime/environ.c >> +++ b/libgfortran/runtime/environ.c > >> #ifdef FALLBACK_SECURE_GETENV >> + >> +#if SUPPORTS_WEAKREF && defined(HAVE___SECURE_GETENV) >> +static char* weak_secure_getenv (const char*) >> + __attribute__((__weakref__("__secure_gettime"))); >> +#endif > > "gettime" vs. "getenv"? ;-) Oops. I'm not at my gcc development box now, please consider a patch to fix this pre-approved. As for testing, I regtested, but my gcc development machine has glibc 2.23 which has secure_getenv so it doesn't exercise the fallback path..
diff --git a/libgfortran/Makefile.in b/libgfortran/Makefile.in index 05b183d..4914a6f 100644 --- a/libgfortran/Makefile.in +++ b/libgfortran/Makefile.in @@ -137,8 +137,9 @@ am__aclocal_m4_deps = $(top_srcdir)/../config/depstand.m4 \ $(top_srcdir)/../ltversion.m4 $(top_srcdir)/../lt~obsolete.m4 \ $(top_srcdir)/acinclude.m4 $(top_srcdir)/../config/acx.m4 \ $(top_srcdir)/../config/no-executables.m4 \ - $(top_srcdir)/../config/math.m4 $(top_srcdir)/../libtool.m4 \ - $(top_srcdir)/configure.ac + $(top_srcdir)/../config/math.m4 \ + $(top_srcdir)/../config/ax_check_define.m4 \ + $(top_srcdir)/../libtool.m4 $(top_srcdir)/configure.ac am__configure_deps = $(am__aclocal_m4_deps) $(CONFIGURE_DEPENDENCIES) \ $(ACLOCAL_M4) am__CONFIG_DISTCLEAN_FILES = config.status config.cache config.log \ diff --git a/libgfortran/libgfortran.h b/libgfortran/libgfortran.h index cfa4fcf..9d9d117 100644 --- a/libgfortran/libgfortran.h +++ b/libgfortran/libgfortran.h @@ -808,9 +808,7 @@ internal_proto(get_unformatted_convert); /* Secure getenv() which returns NULL if running as SUID/SGID. */ #ifndef HAVE_SECURE_GETENV -#ifdef HAVE___SECURE_GETENV -#define secure_getenv __secure_getenv -#elif defined(HAVE_GETUID) && defined(HAVE_GETEUID) \ +#if defined(HAVE_GETUID) && defined(HAVE_GETEUID) \ && defined(HAVE_GETGID) && defined(HAVE_GETEGID) #define FALLBACK_SECURE_GETENV extern char *secure_getenv (const char *); diff --git a/libgfortran/runtime/environ.c b/libgfortran/runtime/environ.c index bf02188..969dcdf 100644 --- a/libgfortran/runtime/environ.c +++ b/libgfortran/runtime/environ.c @@ -37,9 +37,20 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see provided. */ #ifdef FALLBACK_SECURE_GETENV + +#if SUPPORTS_WEAKREF && defined(HAVE___SECURE_GETENV) +static char* weak_secure_getenv (const char*) + __attribute__((__weakref__("__secure_gettime"))); +#endif + char * secure_getenv (const char *name) { +#if SUPPORTS_WEAKREF && defined(HAVE__SECURE_GETENV) + if (weak_secure_getenv) + return weak_secure_getenv (name); +#endif + if ((getuid () == geteuid ()) && (getgid () == getegid ())) return getenv (name); else
Glibc 2.17 made __secure_getenv an officially supported function, and renamed it secure_getenv. The libgfortran configure has checked for both of these, per https://sourceware.org/glibc/wiki/Tips_and_Tricks/secure_getenv. Unfortunately, while the dynamical library (libc.so) retains the __secure_getenv symbol for backwards compatibility, the static library (libc.a) does not. This means that a libgfortran.a compiled against an older glibc will not work if one tries to link against a newer libc.a. This creates problems for providing gfortran binary distributions that work on as many target systems as possible. Thus, retain the support for __secure_getenv but call it only via a weak reference. Regtested on x86_64-pc-linux-gnu, Ok for trunk, 7.x when it reopens, 6, 5? 2017-04-27 Janne Blomqvist <jb@gcc.gnu.org> * libgfortran.h: HAVE_SECURE_GETENV: Don't check HAVE___SECURE_GETENV. * environ/runtime.c (secure_getenv): Use __secure_getenv via a weak reference. * Makefile.in: Regenerated. --- libgfortran/Makefile.in | 5 +++-- libgfortran/libgfortran.h | 4 +--- libgfortran/runtime/environ.c | 11 +++++++++++ 3 files changed, 15 insertions(+), 5 deletions(-)