On Tue, Apr 05, 2016 at 09:33:25AM +0200, Michael Olbrich wrote: > Part of the barebox code and variables are put in separate sections > (.barebox* and .initcall*). When this code is compiled as position > independent code then the compiler creates corresponding .rela.barebox* and > .rela.initcall* sections with the relocation table entries. > These sections don't match the .rela.data* wildcard in the linker script. > As a result, they are not added to the .rela section during linking but are > added individually after it instead. And when the EFI binary is created > from the ELF binary, these sections are not copied. > This has two side effects: > > 1. The corresponding relocations are not handled by the generic relocation > code. 'fixup_tables()' was added to do these relocations manually. > > 2. In the DYNAMIC section, the RELASZ entry contains the total size of > relocations in bytes. This includes the .rela.barebox* and .rela.initcall* > sections. This value is not modified when the EFI binary is created. So the > value is too large. > The generic relocation code in _relocate() used this value when iterating > over all relocation entries. With the wrong RELASZ value it iterates beyond > the end of the .rela section into uninitialized memory. After power-on this > memory is zero and the relocation code interprets this as 'nothing to do', > so there is no visible effect. After a soft reset, random data in that area > may produce a seemingly valid relocation entry, a random address is > modified and barebox crashes. > > This patch adds the .rela.barebox* and .rela.initcall* sections to the > normal .rela section. The RELASZ now contains the correct size and the > generic relocation code works correctly. 'fixup_tables()' must be removed > at the same time to avoid relocating these entries twice. > > Signed-off-by: Michael Olbrich <m.olbrich@xxxxxxxxxxxxxx> > --- > arch/efi/efi/efi.c | 42 --------------------------------------- > arch/efi/lib/elf_x86_64_efi.lds.S | 2 ++ > 2 files changed, 2 insertions(+), 42 deletions(-) Applied, thanks. And thanks for finally fixing this issue :) Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
