On 09/05/19 01:04, Ard Biesheuvel wrote: > In some cases, the CLANG38 toolchain profile in LTO mode emits GOT > based relocations in spite of our attempts to avoid this, by using > hidden visibility, -Bsymbolic etc. > > On AARCH64, we managed to work around this by processing the GOT > based relocations in GenFw. As it turns out, the same issue exists > on 32-bit ARM, but unfortunately, we cannot use a similar trick to > get rid of the GOT entry, and the relocation metadata is insufficient > to locate the GOT entry in the binary. > > A bit of trial and error reveals that switching the linker options from > -pie to -shared in commit e07092edca8442db4a941dbeea0cd196c7bf8ec9 was > not the best approach, and instead, we can pass -pie to the linker > directly (using -Wl,xxx) rather than to the compiler directly, which > turns out to massage the linker in the right way, and prevents if from > emitting GOT based relocations. Your mileage may vary ... > > Signed-off-by: Ard Biesheuvel <ard.biesheu...@linaro.org> > --- > Let's test this on a couple of different Clang versions. If it still > produces problems, the only other way I see is to disable the builds > of platforms that incorporate this module for ARM/CLANG38 [which is > not the end of the world] > > ArmVirtPkg/PrePi/ArmVirtPrePiUniCoreRelocatable.inf | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/ArmVirtPkg/PrePi/ArmVirtPrePiUniCoreRelocatable.inf > b/ArmVirtPkg/PrePi/ArmVirtPrePiUniCoreRelocatable.inf > index 683397b7afd1..9e58e56fce09 100755 > --- a/ArmVirtPkg/PrePi/ArmVirtPrePiUniCoreRelocatable.inf > +++ b/ArmVirtPkg/PrePi/ArmVirtPrePiUniCoreRelocatable.inf > @@ -97,4 +97,4 @@ > gArmTokenSpaceGuid.PcdFvBaseAddress > > [BuildOptions] > - GCC:*_*_*_DLINK_FLAGS = -shared -Wl,-Bsymbolic > -Wl,-T,$(MODULE_DIR)/Scripts/PrePi-PIE.lds > + GCC:*_*_*_DLINK_FLAGS = > -Wl,-Bsymbolic,-pie,-T,$(MODULE_DIR)/Scripts/PrePi-PIE.lds >
Sorry for being late to this patch, I can see [*] it's upstream alrady. Nonetheless: Acked-by: Laszlo Ersek <ler...@redhat.com> [*] Not from my inbox though -- I've got again too much on my plate and am fetching email in batches. But, between my rebasing of "ArmVirtPkg/PlatformBootManagerLib: unload image on EFI_SECURITY_VIOLATION", building it, and attempting to push it, you had pushed this one -- and I did notice that. :) Thanks, Laszlo -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#46938): https://edk2.groups.io/g/devel/message/46938 Mute This Topic: https://groups.io/mt/33144570/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
