| Message ID | 5626A650.7080704@arm.com |
|---|---|
| State | New |
| Headers | show |
On Tue, Oct 20, 2015 at 3:38 PM, Szabolcs Nagy <szabolcs.nagy@arm.com> wrote: > On 20/10/15 06:16, Alan Modra wrote: >> >> On Mon, Oct 19, 2015 at 08:10:32PM +0100, Szabolcs Nagy wrote: >>> >>> On 19/10/15 14:04, Szabolcs Nagy wrote: >>>> >>>> On 19/10/15 12:12, Alan Modra wrote: >>>>> >>>>> On Thu, Oct 15, 2015 at 06:50:50PM +0100, Szabolcs Nagy wrote: >>>>>> >>>>>> A powerpc toolchain built with (or without) --enable-secureplt >>>>>> currently creates a binary that uses bss plt if >>>>>> >>>>>> (1) any of the linked PIC objects have bss plt relocs >>>>>> (2) or all the linked objects are non-PIC or have no relocs, >>>>>> >>>>>> because this is the binutils linker behaviour. >>>>>> >>>>>> This patch passes --secure-plt to the linker which makes the linker >>>>>> warn in case (1) and produce a binary with secure plt in case (2). >>>>> >>>>> >>>>> The idea is OK I think, but >>>>> >>>>>> @@ -574,6 +577,7 @@ ENDIAN_SELECT(" -mbig", " -mlittle", >>>>>> DEFAULT_ASM_ENDIAN) >>>>>> %{R*} \ >>>>>> %(link_shlib) \ >>>>>> %{!T*: %(link_start) } \ >>>>>> +%{!static: %(link_secure_plt_default)} \ >>>>>> %(link_os)" >>>>> >>>>> >>>>> this change needs to be conditional on !mbss-plt too. >>>>> >>>> >>>> OK, will change that. >>>> >>>> if -msecure-plt and -mbss-plt are supposed to affect >>>> linking too (not just code gen) then shall i add >>>> %{msecure-plt: --secure-plt} too? >>>> >>> >>> I added !mbss-plt only for now as a mix of -msecure-plt >>> and -mbss-plt options do not cancel each other in gcc, >> >> >> They do for code-gen since they share the same variable (see >> sysv4.opt), but I guess you meant as far as spec parsing goes. In >> hindsight, it might have been better if I'd spelled -mbss-plt as >> -mno-secure-plt. >> >>> the patch only changes behaviour for a secureplt toolchain. >>> >>> OK to commit? >> >> >> Apologies for not thinking of this before when I first reviewed the >> patch, but have you bootstrapped this patch on powerpc64-linux? I'm >> guessing not, because it occurs to me that --secure-plt is not a >> powerpc64-linux-ld option. So if you try to build a biarch compiler >> with --enable-secure-plt then ld will complain when attempting to link >> 64-bit binaries. >> >> You'll want this on top of your patch: >> > > Added, thanks. (and now built a powerpc64-none-linux-gnu cross > toolchain as well and checked if the correct flags are passed to > the linker with various -msecure-plt/-mbss-plt/-m32/-m64 flags.) > > OK for trunk? > > 2015-10-20 Gregor Richards <gregor.richards@uwaterloo.ca> > Szabolcs Nagy <szabolcs.nagy@arm.com> > > * config/rs6000/secureplt.h (LINK_SECURE_PLT_DEFAULT_SPEC): Define. > * config/rs6000/sysv4.h (LINK_SECURE_PLT_SPEC): Define. > (LINK_SPEC): Add %(link_secure_plt). > (SUBTARGET_EXTRA_SPECS): Add "link_secure_plt". > * config/rs6000/linux64.h (LINK_SECURE_PLT_SPEC): Redefine. > I'm okay if Alan is satisfied. Thanks, David
On Tue, Oct 20, 2015 at 03:40:14PM -0500, David Edelsohn wrote: > On Tue, Oct 20, 2015 at 3:38 PM, Szabolcs Nagy <szabolcs.nagy@arm.com> wrote: > > 2015-10-20 Gregor Richards <gregor.richards@uwaterloo.ca> > > Szabolcs Nagy <szabolcs.nagy@arm.com> > > > > * config/rs6000/secureplt.h (LINK_SECURE_PLT_DEFAULT_SPEC): Define. > > * config/rs6000/sysv4.h (LINK_SECURE_PLT_SPEC): Define. > > (LINK_SPEC): Add %(link_secure_plt). > > (SUBTARGET_EXTRA_SPECS): Add "link_secure_plt". > > * config/rs6000/linux64.h (LINK_SECURE_PLT_SPEC): Redefine. > > > > I'm okay if Alan is satisfied. Committed revision 229102.
diff --git a/gcc/config/rs6000/linux64.h b/gcc/config/rs6000/linux64.h index 9599735..01fb880 100644 --- a/gcc/config/rs6000/linux64.h +++ b/gcc/config/rs6000/linux64.h @@ -174,20 +174,24 @@ extern int dot_symbols; #undef ASM_DEFAULT_SPEC #undef ASM_SPEC #undef LINK_OS_LINUX_SPEC +#undef LINK_SECURE_PLT_SPEC #ifndef RS6000_BI_ARCH #define ASM_DEFAULT_SPEC "-mppc64" #define ASM_SPEC "%(asm_spec64) %(asm_spec_common)" #define LINK_OS_LINUX_SPEC "%(link_os_linux_spec64)" +#define LINK_SECURE_PLT_SPEC "" #else #if DEFAULT_ARCH64_P #define ASM_DEFAULT_SPEC "-mppc%{!m32:64}" #define ASM_SPEC "%{m32:%(asm_spec32)}%{!m32:%(asm_spec64)} %(asm_spec_common)" #define LINK_OS_LINUX_SPEC "%{m32:%(link_os_linux_spec32)}%{!m32:%(link_os_linux_spec64)}" +#define LINK_SECURE_PLT_SPEC "%{m32: " LINK_SECURE_PLT_DEFAULT_SPEC "}" #else #define ASM_DEFAULT_SPEC "-mppc%{m64:64}" #define ASM_SPEC "%{!m64:%(asm_spec32)}%{m64:%(asm_spec64)} %(asm_spec_common)" #define LINK_OS_LINUX_SPEC "%{!m64:%(link_os_linux_spec32)}%{m64:%(link_os_linux_spec64)}" +#define LINK_SECURE_PLT_SPEC "%{!m64: " LINK_SECURE_PLT_DEFAULT_SPEC "}" #endif #endif diff --git a/gcc/config/rs6000/secureplt.h b/gcc/config/rs6000/secureplt.h index b463463..77edf2a 100644 --- a/gcc/config/rs6000/secureplt.h +++ b/gcc/config/rs6000/secureplt.h @@ -18,3 +18,4 @@ along with GCC; see the file COPYING3. If not see <http://www.gnu.org/licenses/>. */ #define CC1_SECURE_PLT_DEFAULT_SPEC "-msecure-plt" +#define LINK_SECURE_PLT_DEFAULT_SPEC "--secure-plt" diff --git a/gcc/config/rs6000/sysv4.h b/gcc/config/rs6000/sysv4.h index 7b2f9bd..1bb400f 100644 --- a/gcc/config/rs6000/sysv4.h +++ b/gcc/config/rs6000/sysv4.h @@ -537,6 +537,9 @@ ENDIAN_SELECT(" -mbig", " -mlittle", DEFAULT_ASM_ENDIAN) #ifndef CC1_SECURE_PLT_DEFAULT_SPEC #define CC1_SECURE_PLT_DEFAULT_SPEC "" #endif +#ifndef LINK_SECURE_PLT_DEFAULT_SPEC +#define LINK_SECURE_PLT_DEFAULT_SPEC "" +#endif /* Pass -G xxx to the compiler. */ #undef CC1_SPEC @@ -567,6 +570,7 @@ ENDIAN_SELECT(" -mbig", " -mlittle", DEFAULT_ASM_ENDIAN) : %(link_start_default) }" #define LINK_START_DEFAULT_SPEC "" +#define LINK_SECURE_PLT_SPEC LINK_SECURE_PLT_DEFAULT_SPEC #undef LINK_SPEC #define LINK_SPEC "\ @@ -574,6 +578,7 @@ ENDIAN_SELECT(" -mbig", " -mlittle", DEFAULT_ASM_ENDIAN) %{R*} \ %(link_shlib) \ %{!T*: %(link_start) } \ +%{!static: %{!mbss-plt: %(link_secure_plt)}} \ %(link_os)" /* Shared libraries are not default. */ @@ -889,6 +894,7 @@ ncrtn.o%s" { "link_os_openbsd", LINK_OS_OPENBSD_SPEC }, \ { "link_os_default", LINK_OS_DEFAULT_SPEC }, \ { "cc1_secure_plt_default", CC1_SECURE_PLT_DEFAULT_SPEC }, \ + { "link_secure_plt", LINK_SECURE_PLT_SPEC }, \ { "cpp_os_ads", CPP_OS_ADS_SPEC }, \ { "cpp_os_yellowknife", CPP_OS_YELLOWKNIFE_SPEC }, \ { "cpp_os_mvme", CPP_OS_MVME_SPEC }, \