diff options
Diffstat (limited to 'arch/arm64/kernel/image.h')
| -rw-r--r-- | arch/arm64/kernel/image.h | 87 |
1 files changed, 54 insertions, 33 deletions
diff --git a/arch/arm64/kernel/image.h b/arch/arm64/kernel/image.h index bc2abb8b1599..f0be31f1dd45 100644 --- a/arch/arm64/kernel/image.h +++ b/arch/arm64/kernel/image.h @@ -26,31 +26,40 @@ * There aren't any ELF relocations we can use to endian-swap values known only * at link time (e.g. the subtraction of two symbol addresses), so we must get * the linker to endian-swap certain values before emitting them. + * + * Note that, in order for this to work when building the ELF64 PIE executable + * (for KASLR), these values should not be referenced via R_AARCH64_ABS64 + * relocations, since these are fixed up at runtime rather than at build time + * when PIE is in effect. So we need to split them up in 32-bit high and low + * words. */ #ifdef CONFIG_CPU_BIG_ENDIAN -#define DATA_LE64(data) \ - ((((data) & 0x00000000000000ff) << 56) | \ - (((data) & 0x000000000000ff00) << 40) | \ - (((data) & 0x0000000000ff0000) << 24) | \ - (((data) & 0x00000000ff000000) << 8) | \ - (((data) & 0x000000ff00000000) >> 8) | \ - (((data) & 0x0000ff0000000000) >> 24) | \ - (((data) & 0x00ff000000000000) >> 40) | \ - (((data) & 0xff00000000000000) >> 56)) +#define DATA_LE32(data) \ + ((((data) & 0x000000ff) << 24) | \ + (((data) & 0x0000ff00) << 8) | \ + (((data) & 0x00ff0000) >> 8) | \ + (((data) & 0xff000000) >> 24)) #else -#define DATA_LE64(data) ((data) & 0xffffffffffffffff) +#define DATA_LE32(data) ((data) & 0xffffffff) #endif +#define DEFINE_IMAGE_LE64(sym, data) \ + sym##_lo32 = DATA_LE32((data) & 0xffffffff); \ + sym##_hi32 = DATA_LE32((data) >> 32) + #ifdef CONFIG_CPU_BIG_ENDIAN -#define __HEAD_FLAG_BE 1 +#define __HEAD_FLAG_BE 1 #else -#define __HEAD_FLAG_BE 0 +#define __HEAD_FLAG_BE 0 #endif -#define __HEAD_FLAG_PAGE_SIZE ((PAGE_SHIFT - 10) / 2) +#define __HEAD_FLAG_PAGE_SIZE ((PAGE_SHIFT - 10) / 2) -#define __HEAD_FLAGS ((__HEAD_FLAG_BE << 0) | \ - (__HEAD_FLAG_PAGE_SIZE << 1)) +#define __HEAD_FLAG_PHYS_BASE 1 + +#define __HEAD_FLAGS ((__HEAD_FLAG_BE << 0) | \ + (__HEAD_FLAG_PAGE_SIZE << 1) | \ + (__HEAD_FLAG_PHYS_BASE << 3)) /* * These will output as part of the Image header, which should be little-endian @@ -58,12 +67,24 @@ * endian swapped in head.S, all are done here for consistency. */ #define HEAD_SYMBOLS \ - _kernel_size_le = DATA_LE64(_end - _text); \ - _kernel_offset_le = DATA_LE64(TEXT_OFFSET); \ - _kernel_flags_le = DATA_LE64(__HEAD_FLAGS); + DEFINE_IMAGE_LE64(_kernel_size_le, _end - _text); \ + DEFINE_IMAGE_LE64(_kernel_offset_le, TEXT_OFFSET); \ + DEFINE_IMAGE_LE64(_kernel_flags_le, __HEAD_FLAGS); #ifdef CONFIG_EFI +__efistub_stext_offset = stext - _text; + +/* + * Prevent the symbol aliases below from being emitted into the kallsyms + * table, by forcing them to be absolute symbols (which are conveniently + * ignored by scripts/kallsyms) rather than section relative symbols. + * The distinction is only relevant for partial linking, and only for symbols + * that are defined within a section declaration (which is not the case for + * the definitions below) so the resulting values will be identical. + */ +#define KALLSYMS_HIDE(sym) ABSOLUTE(sym) + /* * The EFI stub has its own symbol namespace prefixed by __efistub_, to * isolate it from the kernel proper. The following symbols are legally @@ -73,25 +94,25 @@ * linked at. The routines below are all implemented in assembler in a * position independent manner */ -__efistub_memcmp = __pi_memcmp; -__efistub_memchr = __pi_memchr; -__efistub_memcpy = __pi_memcpy; -__efistub_memmove = __pi_memmove; -__efistub_memset = __pi_memset; -__efistub_strlen = __pi_strlen; -__efistub_strcmp = __pi_strcmp; -__efistub_strncmp = __pi_strncmp; -__efistub___flush_dcache_area = __pi___flush_dcache_area; +__efistub_memcmp = KALLSYMS_HIDE(__pi_memcmp); +__efistub_memchr = KALLSYMS_HIDE(__pi_memchr); +__efistub_memcpy = KALLSYMS_HIDE(__pi_memcpy); +__efistub_memmove = KALLSYMS_HIDE(__pi_memmove); +__efistub_memset = KALLSYMS_HIDE(__pi_memset); +__efistub_strlen = KALLSYMS_HIDE(__pi_strlen); +__efistub_strcmp = KALLSYMS_HIDE(__pi_strcmp); +__efistub_strncmp = KALLSYMS_HIDE(__pi_strncmp); +__efistub___flush_dcache_area = KALLSYMS_HIDE(__pi___flush_dcache_area); #ifdef CONFIG_KASAN -__efistub___memcpy = __pi_memcpy; -__efistub___memmove = __pi_memmove; -__efistub___memset = __pi_memset; +__efistub___memcpy = KALLSYMS_HIDE(__pi_memcpy); +__efistub___memmove = KALLSYMS_HIDE(__pi_memmove); +__efistub___memset = KALLSYMS_HIDE(__pi_memset); #endif -__efistub__text = _text; -__efistub__end = _end; -__efistub__edata = _edata; +__efistub__text = KALLSYMS_HIDE(_text); +__efistub__end = KALLSYMS_HIDE(_end); +__efistub__edata = KALLSYMS_HIDE(_edata); #endif |