diff options
Diffstat (limited to 'arch/x86/kernel/vmlinux.lds.S')
| -rw-r--r-- | arch/x86/kernel/vmlinux.lds.S | 42 |
1 files changed, 34 insertions, 8 deletions
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 3c68fe2d46c..f92a0da608c 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -41,6 +41,32 @@ ENTRY(phys_startup_64) jiffies_64 = jiffies; #endif +#if defined(CONFIG_X86_64) && defined(CONFIG_DEBUG_RODATA) +/* + * On 64-bit, align RODATA to 2MB so that even with CONFIG_DEBUG_RODATA + * we retain large page mappings for boundaries spanning kernel text, rodata + * and data sections. + * + * However, kernel identity mappings will have different RWX permissions + * to the pages mapping to text and to the pages padding (which are freed) the + * text section. Hence kernel identity mappings will be broken to smaller + * pages. For 64-bit, kernel text and kernel identity mappings are different, + * so we can enable protection checks that come with CONFIG_DEBUG_RODATA, + * as well as retain 2MB large page mappings for kernel text. + */ +#define X64_ALIGN_DEBUG_RODATA_BEGIN . = ALIGN(HPAGE_SIZE); + +#define X64_ALIGN_DEBUG_RODATA_END \ + . = ALIGN(HPAGE_SIZE); \ + __end_rodata_hpage_align = .; + +#else + +#define X64_ALIGN_DEBUG_RODATA_BEGIN +#define X64_ALIGN_DEBUG_RODATA_END + +#endif + PHDRS { text PT_LOAD FLAGS(5); /* R_E */ data PT_LOAD FLAGS(7); /* RWE */ @@ -90,7 +116,9 @@ SECTIONS EXCEPTION_TABLE(16) :text = 0x9090 + X64_ALIGN_DEBUG_RODATA_BEGIN RO_DATA(PAGE_SIZE) + X64_ALIGN_DEBUG_RODATA_END /* Data */ .data : AT(ADDR(.data) - LOAD_OFFSET) { @@ -107,13 +135,13 @@ SECTIONS PAGE_ALIGNED_DATA(PAGE_SIZE) - CACHELINE_ALIGNED_DATA(CONFIG_X86_L1_CACHE_BYTES) + CACHELINE_ALIGNED_DATA(L1_CACHE_BYTES) DATA_DATA CONSTRUCTORS /* rarely changed data like cpu maps */ - READ_MOSTLY_DATA(CONFIG_X86_INTERNODE_CACHE_BYTES) + READ_MOSTLY_DATA(INTERNODE_CACHE_BYTES) /* End of data section */ _edata = .; @@ -137,12 +165,12 @@ SECTIONS *(.vsyscall_0) } :user - . = ALIGN(CONFIG_X86_L1_CACHE_BYTES); + . = ALIGN(L1_CACHE_BYTES); .vsyscall_fn : AT(VLOAD(.vsyscall_fn)) { *(.vsyscall_fn) } - . = ALIGN(CONFIG_X86_L1_CACHE_BYTES); + . = ALIGN(L1_CACHE_BYTES); .vsyscall_gtod_data : AT(VLOAD(.vsyscall_gtod_data)) { *(.vsyscall_gtod_data) } @@ -166,7 +194,7 @@ SECTIONS } vgetcpu_mode = VVIRT(.vgetcpu_mode); - . = ALIGN(CONFIG_X86_L1_CACHE_BYTES); + . = ALIGN(L1_CACHE_BYTES); .jiffies : AT(VLOAD(.jiffies)) { *(.jiffies) } @@ -291,9 +319,7 @@ SECTIONS __brk_limit = .; } - .end : AT(ADDR(.end) - LOAD_OFFSET) { - _end = .; - } + _end = .; STABS_DEBUG DWARF_DEBUG |