diff options
| -rw-r--r-- | arch/x86/Kconfig | 8 | ||||
| -rw-r--r-- | arch/x86/Makefile | 8 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/head_32.S | 31 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/head_64.S | 1 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/misc.c | 77 | ||||
| -rw-r--r-- | arch/x86/include/asm/page_32_types.h | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/page_64_types.h | 5 | ||||
| -rw-r--r-- | arch/x86/include/asm/page_types.h | 5 |
8 files changed, 97 insertions, 40 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index ff47e23..b710efd 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1716,9 +1716,10 @@ config X86_NEED_RELOCS depends on X86_32 && RELOCATABLE config PHYSICAL_ALIGN - hex "Alignment value to which kernel should be aligned" if X86_32 + hex "Alignment value to which kernel should be aligned" default "0x1000000" - range 0x2000 0x1000000 + range 0x2000 0x1000000 if X86_32 + range 0x200000 0x1000000 if X86_64 ---help--- This value puts the alignment restrictions on physical address where kernel is loaded and run from. Kernel is compiled for an @@ -1736,6 +1737,9 @@ config PHYSICAL_ALIGN end result is that kernel runs from a physical address meeting above alignment restrictions. + On 32-bit this value must be a multiple of 0x2000. On 64-bit + this value must be a multiple of 0x200000. + Don't change this unless you know what you are doing. config HOTPLUG_CPU diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 07639c6..41250fb 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -16,6 +16,10 @@ endif # e.g.: obj-y += foo_$(BITS).o export BITS +ifdef CONFIG_X86_NEED_RELOCS + LDFLAGS_vmlinux := --emit-relocs +endif + ifeq ($(CONFIG_X86_32),y) BITS := 32 UTS_MACHINE := i386 @@ -25,10 +29,6 @@ ifeq ($(CONFIG_X86_32),y) KBUILD_AFLAGS += $(biarch) KBUILD_CFLAGS += $(biarch) - ifdef CONFIG_RELOCATABLE - LDFLAGS_vmlinux := --emit-relocs - endif - KBUILD_CFLAGS += -msoft-float -mregparm=3 -freg-struct-return # Never want PIC in a 32-bit kernel, prevent breakage with GCC built diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S index 1e3184f..5d6f689 100644 --- a/arch/x86/boot/compressed/head_32.S +++ b/arch/x86/boot/compressed/head_32.S @@ -181,8 +181,9 @@ relocated: /* * Do the decompression, and jump to the new kernel.. */ - leal z_extract_offset_negative(%ebx), %ebp /* push arguments for decompress_kernel: */ + pushl $z_output_len /* decompressed length */ + leal z_extract_offset_negative(%ebx), %ebp pushl %ebp /* output address */ pushl $z_input_len /* input_len */ leal input_data(%ebx), %eax @@ -191,33 +192,7 @@ relocated: pushl %eax /* heap area */ pushl %esi /* real mode pointer */ call decompress_kernel - addl $20, %esp - -#if CONFIG_RELOCATABLE -/* - * Find the address of the relocations. - */ - leal z_output_len(%ebp), %edi - -/* - * Calculate the delta between where vmlinux was compiled to run - * and where it was actually loaded. - */ - movl %ebp, %ebx - subl $LOAD_PHYSICAL_ADDR, %ebx - jz 2f /* Nothing to be done if loaded at compiled addr. */ -/* - * Process relocations. - */ - -1: subl $4, %edi - movl (%edi), %ecx - testl %ecx, %ecx - jz 2f - addl %ebx, -__PAGE_OFFSET(%ebx, %ecx) - jmp 1b -2: -#endif + addl $24, %esp /* * Jump to the decompressed kernel. diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index 06e71c2..c337422 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -338,6 +338,7 @@ relocated: leaq input_data(%rip), %rdx /* input_data */ movl $z_input_len, %ecx /* input_len */ movq %rbp, %r8 /* output target address */ + movq $z_output_len, %r9 /* decompressed length */ call decompress_kernel popq %rsi diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index 0319c88..434f077 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -271,6 +271,79 @@ static void error(char *x) asm("hlt"); } +#if CONFIG_X86_NEED_RELOCS +static void handle_relocations(void *output, unsigned long output_len) +{ + int *reloc; + unsigned long delta, map, ptr; + unsigned long min_addr = (unsigned long)output; + unsigned long max_addr = min_addr + output_len; + + /* + * Calculate the delta between where vmlinux was linked to load + * and where it was actually loaded. + */ + delta = min_addr - LOAD_PHYSICAL_ADDR; + if (!delta) { + debug_putstr("No relocation needed... "); + return; + } + debug_putstr("Performing relocations... "); + + /* + * The kernel contains a table of relocation addresses. Those + * addresses have the final load address of the kernel in virtual + * memory. We are currently working in the self map. So we need to + * create an adjustment for kernel memory addresses to the self map. + * This will involve subtracting out the base address of the kernel. + */ + map = delta - __START_KERNEL_map; + + /* + * Process relocations: 32 bit relocations first then 64 bit after. + * Two sets of binary relocations are added to the end of the kernel + * before compression. Each relocation table entry is the kernel + * address of the location which needs to be updated stored as a + * 32-bit value which is sign extended to 64 bits. + * + * Format is: + * + * kernel bits... + * 0 - zero terminator for 64 bit relocations + * 64 bit relocation repeated + * 0 - zero terminator for 32 bit relocations + * 32 bit relocation repeated + * + * So we work backwards from the end of the decompressed image. + */ + for (reloc = output + output_len - sizeof(*reloc); *reloc; reloc--) { + int extended = *reloc; + extended += map; + + ptr = (unsigned long)extended; + if (ptr < min_addr || ptr > max_addr) + error("32-bit relocation outside of kernel!\n"); + + *(uint32_t *)ptr += delta; + } +#ifdef CONFIG_X86_64 + for (reloc--; *reloc; reloc--) { + long extended = *reloc; + extended += map; + + ptr = (unsigned long)extended; + if (ptr < min_addr || ptr > max_addr) + error("64-bit relocation outside of kernel!\n"); + + *(uint64_t *)ptr += delta; + } +#endif +} +#else +static inline void handle_relocations(void *output, unsigned long output_len) +{ } +#endif + static void parse_elf(void *output) { #ifdef CONFIG_X86_64 @@ -325,7 +398,8 @@ static void parse_elf(void *output) asmlinkage void decompress_kernel(void *rmode, memptr heap, unsigned char *input_data, unsigned long input_len, - unsigned char *output) + unsigned char *output, + unsigned long output_len) { real_mode = rmode; @@ -365,6 +439,7 @@ asmlinkage void decompress_kernel(void *rmode, memptr heap, debug_putstr("\nDecompressing Linux... "); decompress(input_data, input_len, NULL, NULL, output, NULL, error); parse_elf(output); + handle_relocations(output, output_len); debug_putstr("done.\nBooting the kernel.\n"); return; } diff --git a/arch/x86/include/asm/page_32_types.h b/arch/x86/include/asm/page_32_types.h index ef17af0..f48b17d 100644 --- a/arch/x86/include/asm/page_32_types.h +++ b/arch/x86/include/asm/page_32_types.h @@ -15,6 +15,8 @@ */ #define __PAGE_OFFSET _AC(CONFIG_PAGE_OFFSET, UL) +#define __START_KERNEL_map __PAGE_OFFSET + #define THREAD_SIZE_ORDER 1 #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER) diff --git a/arch/x86/include/asm/page_64_types.h b/arch/x86/include/asm/page_64_types.h index 6c896fb..43dcd80 100644 --- a/arch/x86/include/asm/page_64_types.h +++ b/arch/x86/include/asm/page_64_types.h @@ -32,11 +32,6 @@ */ #define __PAGE_OFFSET _AC(0xffff880000000000, UL) -#define __PHYSICAL_START ((CONFIG_PHYSICAL_START + \ - (CONFIG_PHYSICAL_ALIGN - 1)) & \ - ~(CONFIG_PHYSICAL_ALIGN - 1)) - -#define __START_KERNEL (__START_KERNEL_map + __PHYSICAL_START) #define __START_KERNEL_map _AC(0xffffffff80000000, UL) /* See Documentation/x86/x86_64/mm.txt for a description of the memory map. */ diff --git a/arch/x86/include/asm/page_types.h b/arch/x86/include/asm/page_types.h index 54c9787..f97fbe3 100644 --- a/arch/x86/include/asm/page_types.h +++ b/arch/x86/include/asm/page_types.h @@ -33,6 +33,11 @@ (((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0 ) | \ VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC) +#define __PHYSICAL_START ALIGN(CONFIG_PHYSICAL_START, \ + CONFIG_PHYSICAL_ALIGN) + +#define __START_KERNEL (__START_KERNEL_map + __PHYSICAL_START) + #ifdef CONFIG_X86_64 #include <asm/page_64_types.h> #else |