On Wed, Jan 31, 2018 at 11:26:59AM -0500, Peter Jones wrote: > Some versions of gcc include a plugin called "annobin", and in some > build systems this is enabled by default. This plugin creates special > ELF note sections to track which ABI-breaking features are used by a > binary, as well as a series of relocations to annotate where. > > If grub is compiled with this feature, then when grub-mkimage translates > the binary to another file format which does not strongly associate > relocation data with sections (i.e. when platform is *-efi), these > relocations appear to be against the .text section rather than the > original note section. When the binary is loaded by the PE runtime > loader, hilarity ensues. > > This issue is not necessarily limited to the annobin, but could arise > any time there are relocations in sections that are not represented in > grub-mkimage's output. > > This patch seeks to avoid this issue by only including relocations that > refer to sections which will be included in the final binary. > > As an aside, this should also obviate the need to avoid -funwind-tables, > -fasynchronous-unwind-tables, and any sections similar to .eh_frame in > the future. I've tested it on x86-64-efi with the following gcc command > line options (as recorded by -grecord-gcc-flags), but I still need to > test the result on some other platforms that have been problematic in > the past (especially ARM Aarch64) before I feel comfortable making > changes to the configure.ac bits: > > GNU C11 7.2.1 20180116 (Red Hat 7.2.1-7) -mno-mmx -mno-sse -mno-sse2 > -mno-sse3 -mno-3dnow -msoft-float -mno-stack-arg-probe -mcmodel=large > -mno-red-zone -m64 -mtune=generic -march=x86-64 -g3 -Os -freg-struct-return > -fno-stack-protector -ffreestanding -funwind-tables > -fasynchronous-unwind-tables -fno-strict-aliasing -fstack-clash-protection > -fno-ident -fplugin=annobin > > Signed-off-by: Peter Jones <pjo...@redhat.com>
In general I am OK with the idea but... > --- > util/grub-mkimagexx.c | 81 > ++++++++++++++++++++++++++++++++++++++++++++++----- > 1 file changed, 73 insertions(+), 8 deletions(-) > > diff --git a/util/grub-mkimagexx.c b/util/grub-mkimagexx.c > index a2bb05439f0..b016b061c8c 100644 > --- a/util/grub-mkimagexx.c > +++ b/util/grub-mkimagexx.c > @@ -708,6 +708,13 @@ arm_get_trampoline_size (Elf_Ehdr *e, > } > #endif > > +static int > +SUFFIX (is_kept_section) (Elf_Shdr *s, const struct > grub_install_image_target_desc *image_target); > +static int > +SUFFIX (is_kept_reloc_section) (Elf_Shdr *s, const struct > grub_install_image_target_desc *image_target, > + Elf_Shdr *sections, Elf_Half section_entsize, > Elf_Half num_sections, > + const char *strtab); Ugh... Could not you create a struct and pass the pointer to it here? Daniel PS Please CC me on the patches next time. _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org https://lists.gnu.org/mailman/listinfo/grub-devel
