On Thu, 5 Sep 2019 at 12:33, Laszlo Ersek <[email protected]> wrote: > > 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 <[email protected]> > > --- > > 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 <[email protected]> >
Thanks. Since the patch is already merged, I'll find another patch to attach it to :-) > [*] 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 (#46997): https://edk2.groups.io/g/devel/message/46997 Mute This Topic: https://groups.io/mt/33144570/21656 Group Owner: [email protected] Unsubscribe: https://edk2.groups.io/g/devel/unsub [[email protected]] -=-=-=-=-=-=-=-=-=-=-=-
