On Mon, Jul 28, 2014 at 02:21:53PM +0100, Michael Brown wrote: > commit c7fb93ec51d462ec3540a729ba446663c26a0505 upstream >
Thanks, I'll use this backport for the 3.11 kernel as well. Cheers, -- Luís > 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). > > Signed-off-by: Michael Brown <[email protected]> > Cc: [email protected] > Cc: [email protected] > --- > arch/x86/boot/header.S | 26 ++++++++++++++++++++++---- > arch/x86/boot/tools/build.c | 37 ++++++++++++++++++++++++++++++------- > 2 files changed, 52 insertions(+), 11 deletions(-) > > diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S > index ec3b8ba..04da6c2 100644 > --- a/arch/x86/boot/header.S > +++ b/arch/x86/boot/header.S > @@ -91,10 +91,9 @@ bs_die: > > .section ".bsdata", "a" > bugger_off_msg: > - .ascii "Direct floppy boot is not supported. " > - .ascii "Use a boot loader program instead.\r\n" > + .ascii "Use a boot loader.\r\n" > .ascii "\n" > - .ascii "Remove disk and press any key to reboot ...\r\n" > + .ascii "Remove disk and press any key to reboot...\r\n" > .byte 0 > > #ifdef CONFIG_EFI_STUB > @@ -108,7 +107,7 @@ coff_header: > #else > .word 0x8664 # x86-64 > #endif > - .word 3 # nr_sections > + .word 4 # nr_sections > .long 0 # TimeDateStamp > .long 0 # PointerToSymbolTable > .long 1 # NumberOfSymbols > @@ -250,6 +249,25 @@ section_table: > .word 0 # NumberOfLineNumbers > .long 0x60500020 # Characteristics (section > flags) > > + # > + # The offset & size fields are filled in by build.c. > + # > + .ascii ".bss" > + .byte 0 > + .byte 0 > + .byte 0 > + .byte 0 > + .long 0 > + .long 0x0 > + .long 0 # Size of initialized data > + # on disk > + .long 0x0 > + .long 0 # PointerToRelocations > + .long 0 # PointerToLineNumbers > + .word 0 # NumberOfRelocations > + .word 0 # NumberOfLineNumbers > + .long 0xc8000080 # Characteristics (section > flags) > + > #endif /* CONFIG_EFI_STUB */ > > # Kernel attributes; used by setup. This is part 1 of the > diff --git a/arch/x86/boot/tools/build.c b/arch/x86/boot/tools/build.c > index 8e15b22..3dafaeb 100644 > --- a/arch/x86/boot/tools/build.c > +++ b/arch/x86/boot/tools/build.c > @@ -142,7 +142,7 @@ static void usage(void) > > #ifdef CONFIG_EFI_STUB > > -static void update_pecoff_section_header(char *section_name, u32 offset, u32 > size) > +static void update_pecoff_section_header_fields(char *section_name, u32 vma, > u32 size, u32 datasz, u32 offset) > { > unsigned int pe_header; > unsigned short num_sections; > @@ -163,10 +163,10 @@ static void update_pecoff_section_header(char > *section_name, u32 offset, u32 siz > put_unaligned_le32(size, section + 0x8); > > /* section header vma field */ > - put_unaligned_le32(offset, section + 0xc); > + put_unaligned_le32(vma, section + 0xc); > > /* section header 'size of initialised data' field */ > - put_unaligned_le32(size, section + 0x10); > + put_unaligned_le32(datasz, section + 0x10); > > /* section header 'file offset' field */ > put_unaligned_le32(offset, section + 0x14); > @@ -178,6 +178,11 @@ static void update_pecoff_section_header(char > *section_name, u32 offset, u32 siz > } > } > > +static void update_pecoff_section_header(char *section_name, u32 offset, u32 > size) > +{ > + update_pecoff_section_header_fields(section_name, offset, size, size, > offset); > +} > + > static void update_pecoff_setup_and_reloc(unsigned int size) > { > u32 setup_offset = 0x200; > @@ -202,9 +207,6 @@ static void update_pecoff_text(unsigned int text_start, > unsigned int file_sz) > > pe_header = get_unaligned_le32(&buf[0x3c]); > > - /* Size of image */ > - put_unaligned_le32(file_sz, &buf[pe_header + 0x50]); > - > /* > * Size of code: Subtract the size of the first sector (512 bytes) > * which includes the header. > @@ -219,6 +221,22 @@ static void update_pecoff_text(unsigned int text_start, > unsigned int file_sz) > update_pecoff_section_header(".text", text_start, text_sz); > } > > +static void update_pecoff_bss(unsigned int file_sz, unsigned int init_sz) > +{ > + unsigned int pe_header; > + unsigned int bss_sz = init_sz - file_sz; > + > + pe_header = get_unaligned_le32(&buf[0x3c]); > + > + /* Size of uninitialized data */ > + put_unaligned_le32(bss_sz, &buf[pe_header + 0x24]); > + > + /* Size of image */ > + put_unaligned_le32(init_sz, &buf[pe_header + 0x50]); > + > + update_pecoff_section_header_fields(".bss", file_sz, bss_sz, 0, 0); > +} > + > #endif /* CONFIG_EFI_STUB */ > > > @@ -270,6 +288,9 @@ int main(int argc, char ** argv) > int fd; > void *kernel; > u32 crc = 0xffffffffUL; > +#ifdef CONFIG_EFI_STUB > + unsigned int init_sz; > +#endif > > /* Defaults for old kernel */ > #ifdef CONFIG_X86_32 > @@ -343,7 +364,9 @@ int main(int argc, char ** argv) > put_unaligned_le32(sys_size, &buf[0x1f4]); > > #ifdef CONFIG_EFI_STUB > - update_pecoff_text(setup_sectors * 512, sz + i + ((sys_size * 16) - > sz)); > + update_pecoff_text(setup_sectors * 512, i + (sys_size * 16)); > + init_sz = get_unaligned_le32(&buf[0x260]); > + update_pecoff_bss(i + (sys_size * 16), init_sz); > > #ifdef CONFIG_X86_64 /* Yes, this is really how we defined it :( */ > efi_stub_entry -= 0x200; > -- > 1.8.4.5 > > -- > To unsubscribe from this list: send the line "unsubscribe stable" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
