Ard: Sorry. I miss this patch. GccBase.lds is used by GCC44~GCC5. GCC44~GCC49 doesn't enable LTO, GCC5 enables LTO. That means RELA section is not used with LTO or without LTO. Right?
Thanks Liming > -----Original Message----- > From: Ard Biesheuvel [mailto:[email protected]] > Sent: Monday, August 22, 2016 3:11 PM > To: Shi, Steven <[email protected]>; Zhu, Yonghong > <[email protected]>; Gao, Liming <[email protected]>; edk2- > devel-01 <[email protected]> > Cc: Ard Biesheuvel <[email protected]> > Subject: Re: [PATCH] BaseTools/GccBase.lds: don't copy RELA section to > PE/COFF > > On 10 August 2016 at 10:55, Ard Biesheuvel <[email protected]> > wrote: > > The CLANG38 toolchain creates a PIE binary at link time. This is > > necessary since the LTO code generation may otherwise result in > > code that cannot execute correctly when loaded above 2 GB. > > > > PIE executables contain a RELA section consisting of dynamic > > relocation entries that are intended for consumption by the loader > > at runtime. For this reason, it has the SHF_ALLOC attribute set by > > default, and will be identified by GenFw as a section that needs to > > be copied into the PE/COFF binary, resulting in waste of space since > > the PE/COFF loader does not use this data at all. > > > > So mark the RELA section as informational: this will prevent the > > linker from setting the SHF_ALLOC attribute, causing GenFw to > > ignore it. > > > > DxeCore.efi before: > > > > Detected 'X64' type PE/COFF image consisting of 3 sections > > Section alignment: 0x40 > > File alignment: 0x40 > > Section '.text' @ 0x00000240 > > File offset: 0x240 > > Virtual size: 0x21000 > > Raw size: 0x21000 > > Section '.data' @ 0x00021240 > > File offset: 0x21240 > > Virtual size: 0x3640 > > Raw size: 0x3640 > > Section '.reloc' @ 0x00024880 > > File offset: 0x24880 > > Virtual size: 0x280 > > Raw size: 0x280 > > > > DxeCore.efi after: > > > > Detected 'X64' type PE/COFF image consisting of 3 sections > > Section alignment: 0x40 > > File alignment: 0x40 > > Section '.text' @ 0x00000240 > > File offset: 0x240 > > Virtual size: 0x1f440 > > Raw size: 0x1f440 > > Section '.data' @ 0x0001f680 > > File offset: 0x1f680 > > Virtual size: 0x3640 > > Raw size: 0x3640 > > Section '.reloc' @ 0x00022cc0 > > File offset: 0x22cc0 > > Virtual size: 0x280 > > Raw size: 0x280 > > > > Contributed-under: TianoCore Contribution Agreement 1.0 > > Signed-off-by: Ard Biesheuvel <[email protected]> > > Steven, Liming: any comments? > > > --- > > BaseTools/Scripts/GccBase.lds | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/BaseTools/Scripts/GccBase.lds b/BaseTools/Scripts/GccBase.lds > > index 281af8a9bd33..900848747144 100644 > > --- a/BaseTools/Scripts/GccBase.lds > > +++ b/BaseTools/Scripts/GccBase.lds > > @@ -54,7 +54,7 @@ SECTIONS { > > KEEP (*(.eh_frame)) > > } > > > > - .rela ALIGN(CONSTANT(COMMONPAGESIZE)) : { > > + .rela (INFO) : { > > *(.rela .rela.*) > > } > > > > -- > > 2.7.4 > > _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
