diff options
| -rw-r--r-- | arch/x86/boot/tools/build.c | 28 |
1 files changed, 26 insertions, 2 deletions
diff --git a/arch/x86/boot/tools/build.c b/arch/x86/boot/tools/build.c index 90d403dfec80..8cac5b6103db 100644 --- a/arch/x86/boot/tools/build.c +++ b/arch/x86/boot/tools/build.c @@ -65,6 +65,8 @@ unsigned long efi_pe_entry; unsigned long efi32_pe_entry; unsigned long kernel_info; unsigned long startup_64; +unsigned long _ehead; +unsigned long _end; /*----------------------------------------------------------------------*/ @@ -232,7 +234,7 @@ static void update_pecoff_text(unsigned int text_start, unsigned int file_sz, { unsigned int pe_header; unsigned int text_sz = file_sz - text_start; - unsigned int bss_sz = init_sz + text_start - file_sz; + unsigned int bss_sz = init_sz - file_sz; pe_header = get_unaligned_le32(&buf[0x3c]); @@ -259,7 +261,7 @@ static void update_pecoff_text(unsigned int text_start, unsigned int file_sz, put_unaligned_le32(file_sz - 512 + bss_sz, &buf[pe_header + 0x1c]); /* Size of image */ - put_unaligned_le32(init_sz + text_start, &buf[pe_header + 0x50]); + put_unaligned_le32(init_sz, &buf[pe_header + 0x50]); /* * Address of entry point for PE/COFF executable @@ -360,6 +362,8 @@ static void parse_zoffset(char *fname) PARSE_ZOFS(p, efi32_pe_entry); PARSE_ZOFS(p, kernel_info); PARSE_ZOFS(p, startup_64); + PARSE_ZOFS(p, _ehead); + PARSE_ZOFS(p, _end); p = strchr(p, '\n'); while (p && (*p == '\r' || *p == '\n')) @@ -444,6 +448,26 @@ int main(int argc, char ** argv) put_unaligned_le32(sys_size, &buf[0x1f4]); init_sz = get_unaligned_le32(&buf[0x260]); +#ifdef CONFIG_EFI_STUB + /* + * The decompression buffer will start at ImageBase. When relocating + * the compressed kernel to its end, we must ensure that the head + * section does not get overwritten. The head section occupies + * [i, i + _ehead), and the destination is [init_sz - _end, init_sz). + * + * At present these should never overlap, because 'i' is at most 32k + * because of SETUP_SECT_MAX, '_ehead' is less than 1k, and the + * calculation of INIT_SIZE in boot/header.S ensures that + * 'init_sz - _end' is at least 64k. + * + * For future-proofing, increase init_sz if necessary. + */ + + if (init_sz - _end < i + _ehead) { + init_sz = (i + _ehead + _end + 4095) & ~4095; + put_unaligned_le32(init_sz, &buf[0x260]); + } +#endif update_pecoff_text(setup_sectors * 512, i + (sys_size * 16), init_sz); efi_stub_entry_update(); |