Message ID | 20190321122445.28990-1-hjl.tools@gmail.com |
---|---|
State | New |
Headers | show |
Series | x86: Don't use apply_irel in static PIE | expand |
On Thu, Mar 21, 2019 at 5:36 AM H.J. Lu <hjl.tools@gmail.com> wrote: > > On x86, since _dl_relocate_static_pie also processes IFUNC relocations, > there is no need to call apply_irel. > > Tested on i686 and x86-64. > > * csu/libc-start.c (apply_irel): Add unused attribute. > * sysdeps/x86/libc-start.h (ARCH_SETUP_IREL): Defined as empty > for static PIE. > --- > csu/libc-start.c | 1 + > sysdeps/x86/libc-start.h | 7 ++++++- > 2 files changed, 7 insertions(+), 1 deletion(-) > > diff --git a/csu/libc-start.c b/csu/libc-start.c > index 5d9c3675fa..07be05f1e9 100644 > --- a/csu/libc-start.c > +++ b/csu/libc-start.c > @@ -66,6 +66,7 @@ uintptr_t __pointer_chk_guard_local > # endif > > static void > +__attribute__ ((unused)) > apply_irel (void) > { > # ifdef IREL > diff --git a/sysdeps/x86/libc-start.h b/sysdeps/x86/libc-start.h > index c76b1d917f..e544867c1d 100644 > --- a/sysdeps/x86/libc-start.h > +++ b/sysdeps/x86/libc-start.h > @@ -17,7 +17,12 @@ > <http://www.gnu.org/licenses/>. */ > > #ifndef SHARED > -# define ARCH_SETUP_IREL() apply_irel () > +# if ENABLE_STATIC_PIE > +/* NB: x86 doesn't use apply_irel in static PIE. */ > +# define ARCH_SETUP_IREL() Will this break non-PIE static when glibc is configured --enable-static-pie? > +# else > +# define ARCH_SETUP_IREL() apply_irel () > +# endif > # define ARCH_APPLY_IREL() > # ifndef ARCH_SETUP_TLS > # define ARCH_SETUP_TLS() __libc_setup_tls () > -- > 2.20.1 >
On 3/21/19, Siva Chandra <sivachandra@google.com> wrote: > On Thu, Mar 21, 2019 at 5:36 AM H.J. Lu <hjl.tools@gmail.com> wrote: >> >> On x86, sinceelf/ifuncmain1static-non-pie _dl_relocate_static_pie also processes IFUNC relocations, >> there is no need to call apply_irel. >> >> Tested on i686 and x86-64. >> >> * csu/libc-start.c (apply_irel): Add unused attribute. >> * sysdeps/x86/libc-start.h (ARCH_SETUP_IREL): Defined as empty >> for static PIE. >> --- >> csu/libc-start.c | 1 + >> sysdeps/x86/libc-start.h | 7 ++++++- >> 2 files changed, 7 insertions(+), 1 deletion(-) >> >> diff --git a/csu/libc-start.c b/csu/libc-start.c >> index 5d9c3675fa..07be05f1e9 100644 >> --- a/csu/libc-start.c >> +++ b/csu/libc-start.c >> @@ -66,6 +66,7 @@ uintptr_t __pointer_chk_guard_local >> # endif >> >> static void >> +__attribute__ ((unused)) >> apply_irel (void) >> { >> # ifdef IREL >> diff --git a/sysdeps/x86/libc-start.h b/sysdeps/x86/libc-start.h >> index c76b1d917f..e544867c1d 100644 >> --- a/sysdeps/x86/libc-start.h >> +++ b/sysdeps/x86/libc-start.h >> @@ -17,7 +17,12 @@ >> <http://www.gnu.org/licenses/>. */ >> >> #ifndef SHARED >> -# define ARCH_SETUP_IREL() apply_irel () >> +# if ENABLE_STATIC_PIE >> +/* NB: x86 doesn't use apply_irel in static PIE. */ >> +# define ARCH_SETUP_IREL() > > Will this break non-PIE static when glibc is configured > --enable-static-pie? You are right. I withdrew my patch. >> +# else >> +# define ARCH_SETUP_IREL() apply_irel () >> +# endif >> # define ARCH_APPLY_IREL() >> # ifndef ARCH_SETUP_TLS >> # define ARCH_SETUP_TLS() __libc_setup_tls () >> -- >> 2.20.1 >> > Thanks.
diff --git a/csu/libc-start.c b/csu/libc-start.c index 5d9c3675fa..07be05f1e9 100644 --- a/csu/libc-start.c +++ b/csu/libc-start.c @@ -66,6 +66,7 @@ uintptr_t __pointer_chk_guard_local # endif static void +__attribute__ ((unused)) apply_irel (void) { # ifdef IREL diff --git a/sysdeps/x86/libc-start.h b/sysdeps/x86/libc-start.h index c76b1d917f..e544867c1d 100644 --- a/sysdeps/x86/libc-start.h +++ b/sysdeps/x86/libc-start.h @@ -17,7 +17,12 @@ <http://www.gnu.org/licenses/>. */ #ifndef SHARED -# define ARCH_SETUP_IREL() apply_irel () +# if ENABLE_STATIC_PIE +/* NB: x86 doesn't use apply_irel in static PIE. */ +# define ARCH_SETUP_IREL() +# else +# define ARCH_SETUP_IREL() apply_irel () +# endif # define ARCH_APPLY_IREL() # ifndef ARCH_SETUP_TLS # define ARCH_SETUP_TLS() __libc_setup_tls ()