init_size does not include any kind of alignment padding. On July 9, 2014 3:20:40 PM PDT, Michael Brown <mbrown@xxxxxxxxxxxxxxxx> wrote: >On 09/07/14 22:41, Michael Brown wrote: >> The PE/COFF headers currently describe only the initialised-data >> portions of the image, and result in no space being allocated for the >> uninitialised-data portions. Consequently, the EFI boot stub will >end >> up overwriting unexpected areas of memory, with unpredictable >results. >> >> Fix by including a .bss section in the PE/COFF headers (functionally >> equivalent to the init_size field in the bzImage header). > >Following on from this: hpa mentioned via IRC that we should also take >alignment into account. I am unsure if init_size already includes >padding for alignment; on my sample kernel init_size is >16MB (with >16MB >alignment), so it looks plausible to me that alignment is already >accounted for. > >If not, then the following trivial patch exposes the desired alignment >via the PE/COFF headers: > >diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S >index 7a6d43a..16ef025 100644 >--- a/arch/x86/boot/header.S >+++ b/arch/x86/boot/header.S >@@ -154,7 +154,7 @@ extra_header_fields: > #else > .quad 0 # ImageBase > #endif >- .long 0x20 # SectionAlignment >+ .long CONFIG_PHYSICAL_ALIGN # SectionAlignment > .long 0x20 # FileAlignment > .word 0 # MajorOperatingSystemVersion > .word 0 # MinorOperatingSystemVersion -- Sent from my mobile phone. Please pardon brevity and lack of formatting. -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
