diff options
Diffstat (limited to 'arch/x86/boot')
| -rw-r--r-- | arch/x86/boot/Makefile | 2 | ||||
| -rw-r--r-- | arch/x86/boot/bioscall.S | 4 | ||||
| -rw-r--r-- | arch/x86/boot/boot.h | 36 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/Makefile | 5 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/head_32.S | 3 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/head_64.S | 39 | ||||
| -rw-r--r-- | arch/x86/boot/main.c | 2 | ||||
| -rw-r--r-- | arch/x86/boot/pmjump.S | 6 |
8 files changed, 67 insertions, 30 deletions
diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile index 6539c50fb9aa..82500962f1b3 100644 --- a/arch/x86/boot/Makefile +++ b/arch/x86/boot/Makefile @@ -100,7 +100,7 @@ $(obj)/zoffset.h: $(obj)/compressed/vmlinux FORCE AFLAGS_header.o += -I$(objtree)/$(obj) $(obj)/header.o: $(obj)/zoffset.h -LDFLAGS_setup.elf := -m elf_i386 -T +LDFLAGS_setup.elf := -m elf_i386 -z noexecstack -T $(obj)/setup.elf: $(src)/setup.ld $(SETUP_OBJS) FORCE $(call if_changed,ld) diff --git a/arch/x86/boot/bioscall.S b/arch/x86/boot/bioscall.S index 5521ea12f44e..aa9b96457584 100644 --- a/arch/x86/boot/bioscall.S +++ b/arch/x86/boot/bioscall.S @@ -32,7 +32,7 @@ intcall: movw %dx, %si movw %sp, %di movw $11, %cx - rep; movsd + rep; movsl /* Pop full state from the stack */ popal @@ -67,7 +67,7 @@ intcall: jz 4f movw %sp, %si movw $11, %cx - rep; movsd + rep; movsl 4: addw $44, %sp /* Restore state and return */ diff --git a/arch/x86/boot/boot.h b/arch/x86/boot/boot.h index ca866f1cca2e..4d79391bb787 100644 --- a/arch/x86/boot/boot.h +++ b/arch/x86/boot/boot.h @@ -110,66 +110,78 @@ typedef unsigned int addr_t; static inline u8 rdfs8(addr_t addr) { + u8 *ptr = (u8 *)absolute_pointer(addr); u8 v; - asm volatile("movb %%fs:%1,%0" : "=q" (v) : "m" (*(u8 *)addr)); + asm volatile("movb %%fs:%1,%0" : "=q" (v) : "m" (*ptr)); return v; } static inline u16 rdfs16(addr_t addr) { + u16 *ptr = (u16 *)absolute_pointer(addr); u16 v; - asm volatile("movw %%fs:%1,%0" : "=r" (v) : "m" (*(u16 *)addr)); + asm volatile("movw %%fs:%1,%0" : "=r" (v) : "m" (*ptr)); return v; } static inline u32 rdfs32(addr_t addr) { + u32 *ptr = (u32 *)absolute_pointer(addr); u32 v; - asm volatile("movl %%fs:%1,%0" : "=r" (v) : "m" (*(u32 *)addr)); + asm volatile("movl %%fs:%1,%0" : "=r" (v) : "m" (*ptr)); return v; } static inline void wrfs8(u8 v, addr_t addr) { - asm volatile("movb %1,%%fs:%0" : "+m" (*(u8 *)addr) : "qi" (v)); + u8 *ptr = (u8 *)absolute_pointer(addr); + asm volatile("movb %1,%%fs:%0" : "+m" (*ptr) : "qi" (v)); } static inline void wrfs16(u16 v, addr_t addr) { - asm volatile("movw %1,%%fs:%0" : "+m" (*(u16 *)addr) : "ri" (v)); + u16 *ptr = (u16 *)absolute_pointer(addr); + asm volatile("movw %1,%%fs:%0" : "+m" (*ptr) : "ri" (v)); } static inline void wrfs32(u32 v, addr_t addr) { - asm volatile("movl %1,%%fs:%0" : "+m" (*(u32 *)addr) : "ri" (v)); + u32 *ptr = (u32 *)absolute_pointer(addr); + asm volatile("movl %1,%%fs:%0" : "+m" (*ptr) : "ri" (v)); } static inline u8 rdgs8(addr_t addr) { + u8 *ptr = (u8 *)absolute_pointer(addr); u8 v; - asm volatile("movb %%gs:%1,%0" : "=q" (v) : "m" (*(u8 *)addr)); + asm volatile("movb %%gs:%1,%0" : "=q" (v) : "m" (*ptr)); return v; } static inline u16 rdgs16(addr_t addr) { + u16 *ptr = (u16 *)absolute_pointer(addr); u16 v; - asm volatile("movw %%gs:%1,%0" : "=r" (v) : "m" (*(u16 *)addr)); + asm volatile("movw %%gs:%1,%0" : "=r" (v) : "m" (*ptr)); return v; } static inline u32 rdgs32(addr_t addr) { + u32 *ptr = (u32 *)absolute_pointer(addr); u32 v; - asm volatile("movl %%gs:%1,%0" : "=r" (v) : "m" (*(u32 *)addr)); + asm volatile("movl %%gs:%1,%0" : "=r" (v) : "m" (*ptr)); return v; } static inline void wrgs8(u8 v, addr_t addr) { - asm volatile("movb %1,%%gs:%0" : "+m" (*(u8 *)addr) : "qi" (v)); + u8 *ptr = (u8 *)absolute_pointer(addr); + asm volatile("movb %1,%%gs:%0" : "+m" (*ptr) : "qi" (v)); } static inline void wrgs16(u16 v, addr_t addr) { - asm volatile("movw %1,%%gs:%0" : "+m" (*(u16 *)addr) : "ri" (v)); + u16 *ptr = (u16 *)absolute_pointer(addr); + asm volatile("movw %1,%%gs:%0" : "+m" (*ptr) : "ri" (v)); } static inline void wrgs32(u32 v, addr_t addr) { - asm volatile("movl %1,%%gs:%0" : "+m" (*(u32 *)addr) : "ri" (v)); + u32 *ptr = (u32 *)absolute_pointer(addr); + asm volatile("movl %1,%%gs:%0" : "+m" (*ptr) : "ri" (v)); } /* Note: these only return true/false, not a signed return value! */ diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index 292b5bc6e3a3..4f15f3fbb2e4 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -38,6 +38,7 @@ KBUILD_CFLAGS += $(call cc-option,-fno-stack-protector) KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member) KBUILD_CFLAGS += $(call cc-disable-warning, gnu) KBUILD_CFLAGS += -Wno-pointer-sign +KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=) # Disable relocation relaxation in case the link is not PIE. KBUILD_CFLAGS += $(call as-option,-Wa$(comma)-mrelax-relocations=no) @@ -57,6 +58,10 @@ else KBUILD_LDFLAGS += $(shell $(LD) --help 2>&1 | grep -q "\-z noreloc-overflow" \ && echo "-z noreloc-overflow -pie --no-dynamic-linker") endif + +KBUILD_LDFLAGS += -z noexecstack +KBUILD_LDFLAGS += $(call ld-option,--no-warn-rwx-segments) + LDFLAGS_vmlinux := -T hostprogs-y := mkpiggy diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S index d7c0fcc1dbf9..b788b986f335 100644 --- a/arch/x86/boot/compressed/head_32.S +++ b/arch/x86/boot/compressed/head_32.S @@ -210,7 +210,7 @@ ENDPROC(efi32_stub_entry) #endif .text -.Lrelocated: +SYM_FUNC_START_LOCAL_NOALIGN(.Lrelocated) /* * Clear BSS (stack is currently empty) @@ -261,6 +261,7 @@ ENDPROC(efi32_stub_entry) */ xorl %ebx, %ebx jmp *%eax +SYM_FUNC_END(.Lrelocated) #ifdef CONFIG_EFI_STUB .data diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index 50c9eeb36f0d..d8164e6abaaf 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -381,11 +381,25 @@ ENTRY(startup_64) /* Save the trampoline address in RCX */ movq %rax, %rcx + /* Set up 32-bit addressable stack */ + leaq TRAMPOLINE_32BIT_STACK_END(%rcx), %rsp + + /* + * Preserve live 64-bit registers on the stack: this is necessary + * because the architecture does not guarantee that GPRs will retain + * their full 64-bit values across a 32-bit mode switch. + */ + pushq %rbp + pushq %rbx + pushq %rsi + /* - * Load the address of trampoline_return() into RDI. - * It will be used by the trampoline to return to the main code. + * Push the 64-bit address of trampoline_return() onto the new stack. + * It will be used by the trampoline to return to the main code. Due to + * the 32-bit mode switch, it cannot be kept it in a register either. */ leaq trampoline_return(%rip), %rdi + pushq %rdi /* Switch to compatibility mode (CS.L = 0 CS.D = 1) via far return */ pushq $__KERNEL32_CS @@ -393,6 +407,11 @@ ENTRY(startup_64) pushq %rax lretq trampoline_return: + /* Restore live 64-bit registers */ + popq %rsi + popq %rbx + popq %rbp + /* Restore the stack, the 32-bit trampoline uses its own stack */ leaq boot_stack_end(%rbx), %rsp @@ -517,7 +536,7 @@ ENDPROC(efi64_stub_entry) #endif .text -.Lrelocated: +SYM_FUNC_START_LOCAL_NOALIGN(.Lrelocated) /* * Clear BSS (stack is currently empty) @@ -546,6 +565,7 @@ ENDPROC(efi64_stub_entry) * Jump to the decompressed kernel. */ jmp *%rax +SYM_FUNC_END(.Lrelocated) /* * Adjust the global offset table @@ -572,7 +592,7 @@ ENDPROC(efi64_stub_entry) /* * This is the 32-bit trampoline that will be copied over to low memory. * - * RDI contains the return address (might be above 4G). + * Return address is at the top of the stack (might be above 4G). * ECX contains the base address of the trampoline memory. * Non zero RDX means trampoline needs to enable 5-level paging. */ @@ -582,9 +602,6 @@ ENTRY(trampoline_32bit_src) movl %eax, %ds movl %eax, %ss - /* Set up new stack */ - leal TRAMPOLINE_32BIT_STACK_END(%ecx), %esp - /* Disable paging */ movl %cr0, %eax btrl $X86_CR0_PG_BIT, %eax @@ -641,9 +658,10 @@ ENTRY(trampoline_32bit_src) lret .code64 -.Lpaging_enabled: +SYM_FUNC_START_LOCAL_NOALIGN(.Lpaging_enabled) /* Return from the trampoline */ - jmp *%rdi + retq +SYM_FUNC_END(.Lpaging_enabled) /* * The trampoline code has a size limit. @@ -653,11 +671,12 @@ ENTRY(trampoline_32bit_src) .org trampoline_32bit_src + TRAMPOLINE_32BIT_CODE_SIZE .code32 -.Lno_longmode: +SYM_FUNC_START_LOCAL_NOALIGN(.Lno_longmode) /* This isn't an x86-64 CPU, so hang intentionally, we cannot continue */ 1: hlt jmp 1b +SYM_FUNC_END(.Lno_longmode) #include "../../kernel/verify_cpu.S" diff --git a/arch/x86/boot/main.c b/arch/x86/boot/main.c index e3add857c2c9..c421af5a3cdc 100644 --- a/arch/x86/boot/main.c +++ b/arch/x86/boot/main.c @@ -33,7 +33,7 @@ static void copy_boot_params(void) u16 cl_offset; }; const struct old_cmdline * const oldcmd = - (const struct old_cmdline *)OLD_CL_ADDRESS; + absolute_pointer(OLD_CL_ADDRESS); BUILD_BUG_ON(sizeof(boot_params) != 4096); memcpy(&boot_params.hdr, &hdr, sizeof(hdr)); diff --git a/arch/x86/boot/pmjump.S b/arch/x86/boot/pmjump.S index c22f9a7d1aeb..81658fe35380 100644 --- a/arch/x86/boot/pmjump.S +++ b/arch/x86/boot/pmjump.S @@ -40,13 +40,13 @@ GLOBAL(protected_mode_jump) # Transition to 32-bit mode .byte 0x66, 0xea # ljmpl opcode -2: .long in_pm32 # offset +2: .long .Lin_pm32 # offset .word __BOOT_CS # segment ENDPROC(protected_mode_jump) .code32 .section ".text32","ax" -GLOBAL(in_pm32) +SYM_FUNC_START_LOCAL_NOALIGN(.Lin_pm32) # Set up data segments for flat 32-bit mode movl %ecx, %ds movl %ecx, %es @@ -72,4 +72,4 @@ GLOBAL(in_pm32) lldt %cx jmpl *%eax # Jump to the 32-bit entrypoint -ENDPROC(in_pm32) +SYM_FUNC_END(.Lin_pm32) |