diff options
Diffstat (limited to 'arch/i386/boot/compressed')
| -rw-r--r-- | arch/i386/boot/compressed/Makefile | 28 | ||||
| -rw-r--r-- | arch/i386/boot/compressed/head.S | 185 | ||||
| -rw-r--r-- | arch/i386/boot/compressed/misc.c | 264 | ||||
| -rw-r--r-- | arch/i386/boot/compressed/relocs.c | 625 | ||||
| -rw-r--r-- | arch/i386/boot/compressed/vmlinux.lds | 43 | ||||
| -rw-r--r-- | arch/i386/boot/compressed/vmlinux.scr | 3 |
6 files changed, 947 insertions, 201 deletions
diff --git a/arch/i386/boot/compressed/Makefile b/arch/i386/boot/compressed/Makefile index 258ea95224f..a661217f33e 100644 --- a/arch/i386/boot/compressed/Makefile +++ b/arch/i386/boot/compressed/Makefile @@ -4,22 +4,42 @@ # create a compressed vmlinux image from the original vmlinux # -targets := vmlinux vmlinux.bin vmlinux.bin.gz head.o misc.o piggy.o +targets := vmlinux vmlinux.bin vmlinux.bin.gz head.o misc.o piggy.o \ + vmlinux.bin.all vmlinux.relocs EXTRA_AFLAGS := -traditional -LDFLAGS_vmlinux := -Ttext $(IMAGE_OFFSET) -e startup_32 +LDFLAGS_vmlinux := -T +CFLAGS_misc.o += -fPIC +hostprogs-y := relocs -$(obj)/vmlinux: $(obj)/head.o $(obj)/misc.o $(obj)/piggy.o FORCE +$(obj)/vmlinux: $(src)/vmlinux.lds $(obj)/head.o $(obj)/misc.o $(obj)/piggy.o FORCE $(call if_changed,ld) @: $(obj)/vmlinux.bin: vmlinux FORCE $(call if_changed,objcopy) +quiet_cmd_relocs = RELOCS $@ + cmd_relocs = $(obj)/relocs $< > $@;$(obj)/relocs --abs-relocs $< +$(obj)/vmlinux.relocs: vmlinux $(obj)/relocs FORCE + $(call if_changed,relocs) + +vmlinux.bin.all-y := $(obj)/vmlinux.bin +vmlinux.bin.all-$(CONFIG_RELOCATABLE) += $(obj)/vmlinux.relocs +quiet_cmd_relocbin = BUILD $@ + cmd_relocbin = cat $(filter-out FORCE,$^) > $@ +$(obj)/vmlinux.bin.all: $(vmlinux.bin.all-y) FORCE + $(call if_changed,relocbin) + +ifdef CONFIG_RELOCATABLE +$(obj)/vmlinux.bin.gz: $(obj)/vmlinux.bin.all FORCE + $(call if_changed,gzip) +else $(obj)/vmlinux.bin.gz: $(obj)/vmlinux.bin FORCE $(call if_changed,gzip) +endif LDFLAGS_piggy.o := -r --format binary --oformat elf32-i386 -T -$(obj)/piggy.o: $(obj)/vmlinux.scr $(obj)/vmlinux.bin.gz FORCE +$(obj)/piggy.o: $(src)/vmlinux.scr $(obj)/vmlinux.bin.gz FORCE $(call if_changed,ld) diff --git a/arch/i386/boot/compressed/head.S b/arch/i386/boot/compressed/head.S index b5893e4ecd3..f395a4bb38b 100644 --- a/arch/i386/boot/compressed/head.S +++ b/arch/i386/boot/compressed/head.S @@ -26,9 +26,11 @@ #include <linux/linkage.h> #include <asm/segment.h> #include <asm/page.h> +#include <asm/boot.h> +.section ".text.head" .globl startup_32 - + startup_32: cld cli @@ -37,93 +39,142 @@ startup_32: movl %eax,%es movl %eax,%fs movl %eax,%gs + movl %eax,%ss - lss stack_start,%esp - xorl %eax,%eax -1: incl %eax # check that A20 really IS enabled - movl %eax,0x000000 # loop forever if it isn't - cmpl %eax,0x100000 - je 1b +/* Calculate the delta between where we were compiled to run + * at and where we were actually loaded at. This can only be done + * with a short local call on x86. Nothing else will tell us what + * address we are running at. The reserved chunk of the real-mode + * data at 0x34-0x3f are used as the stack for this calculation. + * Only 4 bytes are needed. + */ + leal 0x40(%esi), %esp + call 1f +1: popl %ebp + subl $1b, %ebp + +/* %ebp contains the address we are loaded at by the boot loader and %ebx + * contains the address where we should move the kernel image temporarily + * for safe in-place decompression. + */ + +#ifdef CONFIG_RELOCATABLE + movl %ebp, %ebx + addl $(CONFIG_PHYSICAL_ALIGN - 1), %ebx + andl $(~(CONFIG_PHYSICAL_ALIGN - 1)), %ebx +#else + movl $LOAD_PHYSICAL_ADDR, %ebx +#endif + + /* Replace the compressed data size with the uncompressed size */ + subl input_len(%ebp), %ebx + movl output_len(%ebp), %eax + addl %eax, %ebx + /* Add 8 bytes for every 32K input block */ + shrl $12, %eax + addl %eax, %ebx + /* Add 32K + 18 bytes of extra slack */ + addl $(32768 + 18), %ebx + /* Align on a 4K boundary */ + addl $4095, %ebx + andl $~4095, %ebx + +/* Copy the compressed kernel to the end of our buffer + * where decompression in place becomes safe. + */ + pushl %esi + leal _end(%ebp), %esi + leal _end(%ebx), %edi + movl $(_end - startup_32), %ecx + std + rep + movsb + cld + popl %esi + +/* Compute the kernel start address. + */ +#ifdef CONFIG_RELOCATABLE + addl $(CONFIG_PHYSICAL_ALIGN - 1), %ebp + andl $(~(CONFIG_PHYSICAL_ALIGN - 1)), %ebp +#else + movl $LOAD_PHYSICAL_ADDR, %ebp +#endif /* - * Initialize eflags. Some BIOS's leave bits like NT set. This would - * confuse the debugger if this code is traced. - * XXX - best to initialize before switching to protected mode. + * Jump to the relocated address. */ - pushl $0 - popfl + leal relocated(%ebx), %eax + jmp *%eax +.section ".text" +relocated: + /* * Clear BSS */ xorl %eax,%eax - movl $_edata,%edi - movl $_end,%ecx + leal _edata(%ebx),%edi + leal _end(%ebx), %ecx subl %edi,%ecx cld rep stosb + +/* + * Setup the stack for the decompressor + */ + leal stack_end(%ebx), %esp + /* * Do the decompression, and jump to the new kernel.. */ - subl $16,%esp # place for structure on the stack - movl %esp,%eax + movl output_len(%ebx), %eax + pushl %eax + pushl %ebp # output address + movl input_len(%ebx), %eax + pushl %eax # input_len + leal input_data(%ebx), %eax + pushl %eax # input_data + leal _end(%ebx), %eax + pushl %eax # end of the image as third argument pushl %esi # real mode pointer as second arg - pushl %eax # address of structure as first arg call decompress_kernel - orl %eax,%eax - jnz 3f - popl %esi # discard address - popl %esi # real mode pointer - xorl %ebx,%ebx - ljmp $(__BOOT_CS), $__PHYSICAL_START + addl $20, %esp + popl %ecx +#if CONFIG_RELOCATABLE +/* Find the address of the relocations. + */ + movl %ebp, %edi + addl %ecx, %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. */ /* - * We come here, if we were loaded high. - * We need to move the move-in-place routine down to 0x1000 - * and then start it with the buffer addresses in registers, - * which we got from the stack. + * Process relocations. */ -3: - movl $move_routine_start,%esi - movl $0x1000,%edi - movl $move_routine_end,%ecx - subl %esi,%ecx - addl $3,%ecx - shrl $2,%ecx - cld - rep - movsl - - popl %esi # discard the address - popl %ebx # real mode pointer - popl %esi # low_buffer_start - popl %ecx # lcount - popl %edx # high_buffer_start - popl %eax # hcount - movl $__PHYSICAL_START,%edi - cli # make sure we don't get interrupted - ljmp $(__BOOT_CS), $0x1000 # and jump to the move routine + +1: subl $4, %edi + movl 0(%edi), %ecx + testl %ecx, %ecx + jz 2f + addl %ebx, -__PAGE_OFFSET(%ebx, %ecx) + jmp 1b +2: +#endif /* - * Routine (template) for moving the decompressed kernel in place, - * if we were high loaded. This _must_ PIC-code ! + * Jump to the decompressed kernel. */ -move_routine_start: - movl %ecx,%ebp - shrl $2,%ecx - rep - movsl - movl %ebp,%ecx - andl $3,%ecx - rep - movsb - movl %edx,%esi - movl %eax,%ecx # NOTE: rep movsb won't move if %ecx == 0 - addl $3,%ecx - shrl $2,%ecx - rep - movsl - movl %ebx,%esi # Restore setup pointer xorl %ebx,%ebx - ljmp $(__BOOT_CS), $__PHYSICAL_START -move_routine_end: + jmp *%ebp + +.bss +.balign 4 +stack: + .fill 4096, 1, 0 +stack_end: diff --git a/arch/i386/boot/compressed/misc.c b/arch/i386/boot/compressed/misc.c index b2ccd543410..1ce7017fd62 100644 --- a/arch/i386/boot/compressed/misc.c +++ b/arch/i386/boot/compressed/misc.c @@ -9,11 +9,94 @@ * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996 */ +#undef CONFIG_PARAVIRT #include <linux/linkage.h> #include <linux/vmalloc.h> #include <linux/screen_info.h> #include <asm/io.h> #include <asm/page.h> +#include <asm/boot.h> + +/* WARNING!! + * This code is compiled with -fPIC and it is relocated dynamically + * at run time, but no relocation processing is performed. + * This means that it is not safe to place pointers in static structures. + */ + +/* + * Getting to provable safe in place decompression is hard. + * Worst case behaviours need to be analized. + * Background information: + * + * The file layout is: + * magic[2] + * method[1] + * flags[1] + * timestamp[4] + * extraflags[1] + * os[1] + * compressed data blocks[N] + * crc[4] orig_len[4] + * + * resulting in 18 bytes of non compressed data overhead. + * + * Files divided into blocks + * 1 bit (last block flag) + * 2 bits (block type) + * + * 1 block occurs every 32K -1 bytes or when there 50% compression has been achieved. + * The smallest block type encoding is always used. + * + * stored: + * 32 bits length in bytes. + * + * fixed: + * magic fixed tree. + * symbols. + * + * dynamic: + * dynamic tree encoding. + * symbols. + * + * + * The buffer for decompression in place is the length of the + * uncompressed data, plus a small amount extra to keep the algorithm safe. + * The compressed data is placed at the end of the buffer. The output + * pointer is placed at the start of the buffer and the input pointer + * is placed where the compressed data starts. Problems will occur + * when the output pointer overruns the input pointer. + * + * The output pointer can only overrun the input pointer if the input + * pointer is moving faster than the output pointer. A condition only + * triggered by data whose compressed form is larger than the uncompressed + * form. + * + * The worst case at the block level is a growth of the compressed data + * of 5 bytes per 32767 bytes. + * + * The worst case internal to a compressed block is very hard to figure. + * The worst case can at least be boundined by having one bit that represents + * 32764 bytes and then all of the rest of the bytes representing the very + * very last byte. + * + * All of which is enough to compute an amount of extra data that is required + * to be safe. To avoid problems at the block level allocating 5 extra bytes + * per 32767 bytes of data is sufficient. To avoind problems internal to a block + * adding an extra 32767 bytes (the worst case uncompressed block size) is + * sufficient, to ensure that in the worst case the decompressed data for + * block will stop the byte before the compressed data for a block begins. + * To avoid problems with the compressed data's meta information an extra 18 + * bytes are needed. Leading to the formula: + * + * extra_bytes = (uncompressed_size >> 12) + 32768 + 18 + decompressor_size. + * + * Adding 8 bytes per 32K is a bit excessive but much easier to calculate. + * Adding 32768 instead of 32767 just makes for round numbers. + * Adding the decompressor_size is necessary as it musht live after all + * of the data as well. Last I measured the decompressor is about 14K. + * 10K of actuall data and 4K of bss. + * + */ /* * gzip declarations @@ -30,15 +113,20 @@ typedef unsigned char uch; typedef unsigned short ush; typedef unsigned long ulg; -#define WSIZE 0x8000 /* Window size must be at least 32k, */ - /* and a power of two */ +#define WSIZE 0x80000000 /* Window size must be at least 32k, + * and a power of two + * We don't actually have a window just + * a huge output buffer so I report + * a 2G windows size, as that should + * always be larger than our output buffer. + */ -static uch *inbuf; /* input buffer */ -static uch window[WSIZE]; /* Sliding window buffer */ +static uch *inbuf; /* input buffer */ +static uch *window; /* Sliding window buffer, (and final output buffer) */ -static unsigned insize = 0; /* valid bytes in inbuf */ -static unsigned inptr = 0; /* index of next byte to be processed in inbuf */ -static unsigned outcnt = 0; /* bytes in output buffer */ +static unsigned insize; /* valid bytes in inbuf */ +static unsigned inptr; /* index of next byte to be processed in inbuf */ +static unsigned outcnt; /* bytes in output buffer */ /* gzip flag byte */ #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */ @@ -89,8 +177,6 @@ extern unsigned char input_data[]; extern int input_len; static long bytes_out = 0; -static uch *output_data; -static unsigned long output_ptr = 0; static void *malloc(int size); static void free(void *where); @@ -100,24 +186,17 @@ static void *memcpy(void *dest, const void *src, unsigned n); static void putstr(const char *); -extern int end; -static long free_mem_ptr = (long)&end; -static long free_mem_end_ptr; +static unsigned long free_mem_ptr; +static unsigned long free_mem_end_ptr; -#define INPLACE_MOVE_ROUTINE 0x1000 -#define LOW_BUFFER_START 0x2000 -#define LOW_BUFFER_MAX 0x90000 #define HEAP_SIZE 0x3000 -static unsigned int low_buffer_end, low_buffer_size; -static int high_loaded =0; -static uch *high_buffer_start /* = (uch *)(((ulg)&end) + HEAP_SIZE)*/; static char *vidmem = (char *)0xb8000; static int vidport; static int lines, cols; #ifdef CONFIG_X86_NUMAQ -static void * xquad_portio = NULL; +void *xquad_portio; #endif #include "../../../../lib/inflate.c" @@ -151,7 +230,7 @@ static void gzip_mark(void **ptr) static void gzip_release(void **ptr) { - free_mem_ptr = (long) *ptr; + free_mem_ptr = (unsigned long) *ptr; } static void scroll(void) @@ -179,7 +258,7 @@ static void putstr(const char *s) y--; } } else { - vidmem [ ( x + cols * y ) * 2 ] = c; + vidmem [ ( x + cols * y ) * 2 ] = c; if ( ++x >= cols ) { x = 0; if ( ++y >= lines ) { @@ -224,58 +303,31 @@ static void* memcpy(void* dest, const void* src, unsigned n) */ static int fill_inbuf(void) { - if (insize != 0) { - error("ran out of input data"); - } - - inbuf = input_data; - insize = input_len; - inptr = 1; - return inbuf[0]; + error("ran out of input data"); + return 0; } /* =========================================================================== * Write the output window window[0..outcnt-1] and update crc and bytes_out. * (Used for the decompressed data only.) */ -static void flush_window_low(void) -{ - ulg c = crc; /* temporary variable */ - unsigned n; - uch *in, *out, ch; - - in = window; - out = &output_data[output_ptr]; - for (n = 0; n < outcnt; n++) { - ch = *out++ = *in++; - c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8); - } - crc = c; - bytes_out += (ulg)outcnt; - output_ptr += (ulg)outcnt; - outcnt = 0; -} - -static void flush_window_high(void) -{ - ulg c = crc; /* temporary variable */ - unsigned n; - uch *in, ch; - in = window; - for (n = 0; n < outcnt; n++) { - ch = *output_data++ = *in++; - if ((ulg)output_data == low_buffer_end) output_data=high_buffer_start; - c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8); - } - crc = c; - bytes_out += (ulg)outcnt; - outcnt = 0; -} - static void flush_window(void) { - if (high_loaded) flush_window_high(); - else flush_window_low(); + /* With my window equal to my output buffer + * I only need to compute the crc here. + */ + ulg c = crc; /* temporary variable */ + unsigned n; + uch *in, ch; + + in = window; + for (n = 0; n < outcnt; n++) { + ch = *in++; + c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8); + } + crc = c; + bytes_out += (ulg)outcnt; + outcnt = 0; } static void error(char *x) @@ -287,66 +339,8 @@ static void error(char *x) while(1); /* Halt */ } -#define STACK_SIZE (4096) - -long user_stack [STACK_SIZE]; - -struct { - long * a; - short b; - } stack_start = { & user_stack [STACK_SIZE] , __BOOT_DS }; - -static void setup_normal_output_buffer(void) -{ -#ifdef STANDARD_MEMORY_BIOS_CALL - if (RM_EXT_MEM_K < 1024) error("Less than 2MB of memory"); -#else - if ((RM_ALT_MEM_K > RM_EXT_MEM_K ? RM_ALT_MEM_K : RM_EXT_MEM_K) < 1024) error("Less than 2MB of memory"); -#endif - output_data = (unsigned char *)__PHYSICAL_START; /* Normally Points to 1M */ - free_mem_end_ptr = (long)real_mode; -} - -struct moveparams { - uch *low_buffer_start; int lcount; - uch *high_buffer_start; int hcount; -}; - -static void setup_output_buffer_if_we_run_high(struct moveparams *mv) -{ - high_buffer_start = (uch *)(((ulg)&end) + HEAP_SIZE); -#ifdef STANDARD_MEMORY_BIOS_CALL - if (RM_EXT_MEM_K < (3*1024)) error("Less than 4MB of memory"); -#else - if ((RM_ALT_MEM_K > RM_EXT_MEM_K ? RM_ALT_MEM_K : RM_EXT_MEM_K) < (3*1024)) error("Less than 4MB of memory"); -#endif - mv->low_buffer_start = output_data = (unsigned char *)LOW_BUFFER_START; - low_buffer_end = ((unsigned int)real_mode > LOW_BUFFER_MAX - ? LOW_BUFFER_MAX : (unsigned int)real_mode) & ~0xfff; - low_buffer_size = low_buffer_end - LOW_BUFFER_START; - high_loaded = 1; - free_mem_end_ptr = (long)high_buffer_start; - if ( (__PHYSICAL_START + low_buffer_size) > ((ulg)high_buffer_start)) { - high_buffer_start = (uch *)(__PHYSICAL_START + low_buffer_size); - mv->hcount = 0; /* say: we need not to move high_buffer */ - } - else mv->hcount = -1; - mv->high_buffer_start = high_buffer_start; -} - -static void close_output_buffer_if_we_run_high(struct moveparams *mv) -{ - if (bytes_out > low_buffer_size) { - mv->lcount = low_buffer_size; - if (mv->hcount) - mv->hcount = bytes_out - low_buffer_size; - } else { - mv->lcount = bytes_out; - mv->hcount = 0; - } -} - -asmlinkage int decompress_kernel(struct moveparams *mv, void *rmode) +asmlinkage void decompress_kernel(void *rmode, unsigned long end, + uch *input_data, unsigned long input_len, uch *output) { real_mode = rmode; @@ -361,13 +355,25 @@ asmlinkage int decompress_kernel(struct moveparams *mv, void *rmode) lines = RM_SCREEN_INFO.orig_video_lines; cols = RM_SCREEN_INFO.orig_video_cols; - if (free_mem_ptr < 0x100000) setup_normal_output_buffer(); - else setup_output_buffer_if_we_run_high(mv); + window = output; /* Output buffer (Normally at 1M) */ + free_mem_ptr = end; /* Heap */ + free_mem_end_ptr = end + HEAP_SIZE; + inbuf = input_data; /* Input buffer */ + insize = input_len; + inptr = 0; + + if ((u32)output & (CONFIG_PHYSICAL_ALIGN -1)) + error("Destination address not CONFIG_PHYSICAL_ALIGN aligned"); + if (end > ((-__PAGE_OFFSET-(512 <<20)-1) & 0x7fffffff)) + error("Destination address too large"); +#ifndef CONFIG_RELOCATABLE + if ((u32)output != LOAD_PHYSICAL_ADDR) + error("Wrong destination address"); +#endif makecrc(); putstr("Uncompressing Linux... "); gunzip(); putstr("Ok, booting the kernel.\n"); - if (high_loaded) close_output_buffer_if_we_run_high(mv); - return high_loaded; + return; } diff --git a/arch/i386/boot/compressed/relocs.c b/arch/i386/boot/compressed/relocs.c new file mode 100644 index 00000000000..468da89153c --- /dev/null +++ b/arch/i386/boot/compressed/relocs.c @@ -0,0 +1,625 @@ +#include <stdio.h> +#include <stdarg.h> +#include <stdlib.h> +#include <stdint.h> +#include <string.h> +#include <errno.h> +#include <unistd.h> +#include <elf.h> +#include <byteswap.h> +#define USE_BSD +#include <endian.h> + +#define MAX_SHDRS 100 +static Elf32_Ehdr ehdr; +static Elf32_Shdr shdr[MAX_SHDRS]; +static Elf32_Sym *symtab[MAX_SHDRS]; +static Elf32_Rel *reltab[MAX_SHDRS]; +static char *strtab[MAX_SHDRS]; +static unsigned long reloc_count, reloc_idx; +static unsigned long *relocs; + +/* + * Following symbols have been audited. There values are constant and do + * not change if bzImage is loaded at a different physical address than + * the address for which it has been compiled. Don't warn user about + * absolute relocations present w.r.t these symbols. + */ +static const char* safe_abs_relocs[] = { + "__kernel_vsyscall", + "__kernel_rt_sigreturn", + "__kernel_sigreturn", + "SYSENTER_RETURN", +}; + +static int is_safe_abs_reloc(const char* sym_name) +{ + int i, array_size; + + array_size = sizeof(safe_abs_relocs)/sizeof(char*); + + for(i = 0; i < array_size; i++) { + if (!strcmp(sym_name, safe_abs_relocs[i])) + /* Match found */ + return 1; + } + return 0; +} + +static void die(char *fmt, ...) +{ + va_list ap; + va_start(ap, fmt); + vfprintf(stderr, fmt, ap); + va_end(ap); + exit(1); +} + +static const char *sym_type(unsigned type) +{ + static const char *type_name[] = { +#define SYM_TYPE(X) [X] = #X + SYM_TYPE(STT_NOTYPE), + SYM_TYPE(STT_OBJECT), + SYM_TYPE(STT_FUNC), + SYM_TYPE(STT_SECTION), + SYM_TYPE(STT_FILE), + SYM_TYPE(STT_COMMON), + SYM_TYPE(STT_TLS), +#undef SYM_TYPE + }; + const char *name = "unknown sym type name"; + if (type < sizeof(type_name)/sizeof(type_name[0])) { + name = type_name[type]; + } + return name; +} + +static const char *sym_bind(unsigned bind) +{ + static const char *bind_name[] = { +#define SYM_BIND(X) [X] = #X + SYM_BIND(STB_LOCAL), + SYM_BIND(STB_GLOBAL), + SYM_BIND(STB_WEAK), +#undef SYM_BIND + }; + const char *name = "unknown sym bind name"; + if (bind < sizeof(bind_name)/sizeof(bind_name[0])) { + name = bind_name[bind]; + } + return name; +} + +static const char *sym_visibility(unsigned visibility) +{ + static const char *visibility_name[] = { +#define SYM_VISIBILITY(X) [X] = #X + SYM_VISIBILITY(STV_DEFAULT), + SYM_VISIBILITY(STV_INTERNAL), + SYM_VISIBILITY(STV_HIDDEN), + SYM_VISIBILITY(STV_PROTECTED), +#undef SYM_VISIBILITY + }; + const char *name = "unknown sym visibility name"; + if (visibility < sizeof(visibility_name)/sizeof(visibility_name[0])) { + name = visibility_name[visibility]; + } + return name; +} + +static const char *rel_type(unsigned type) +{ + static const char *type_name[] = { +#define REL_TYPE(X) [X] = #X + REL_TYPE(R_386_NONE), + REL_TYPE(R_386_32), + REL_TYPE(R_386_PC32), + REL_TYPE(R_386_GOT32), + REL_TYPE(R_386_PLT32), + REL_TYPE(R_386_COPY), + REL_TYPE(R_386_GLOB_DAT), + REL_TYPE(R_386_JMP_SLOT), + REL_TYPE(R_386_RELATIVE), + REL_TYPE(R_386_GOTOFF), + REL_TYPE(R_386_GOTPC), +#undef REL_TYPE + }; + const char *name = "unknown type rel type name"; + if (type < sizeof(type_name)/sizeof(type_name[0])) { + name = type_name[type]; + } + return name; +} + +static const char *sec_name(unsigned shndx) +{ + const char *sec_strtab; + const char *name; + sec_strtab = strtab[ehdr.e_shstrndx]; + name = "<noname>"; + if (shndx < ehdr.e_shnum) { + name = sec_strtab + shdr[shndx].sh_name; + } + else if (shndx == SHN_ABS) { + name = "ABSOLUTE"; + } + else if (shndx == SHN_COMMON) { + name = "COMMON"; + } + return name; +} + +static const char *sym_name(const char *sym_strtab, Elf32_Sym *sym) +{ + const char *name; + name = "<noname>"; + if (sym->st_name) { + name = sym_strtab + sym->st_name; + } + else { + name = sec_name(shdr[sym->st_shndx].sh_name); + } + return name; +} + + + +#if BYTE_ORDER == LITTLE_ENDIAN +#define le16_to_cpu(val) (val) +#define le32_to_cpu(val) (val) +#endif +#if BYTE_ORDER == BIG_ENDIAN +#define le16_to_cpu(val) bswap_16(val) +#define le32_to_cpu(val) bswap_32(val) +#endif + +static uint16_t elf16_to_cpu(uint16_t val) +{ + return le16_to_cpu(val); +} + +static uint32_t elf32_to_cpu(uint32_t val) +{ + return le32_to_cpu(val); +} + +static void read_ehdr(FILE *fp) +{ + if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1) { + die("Cannot read ELF header: %s\n", + strerror(errno)); + } + if (memcmp(ehdr.e_ident, ELFMAG, 4) != 0) { + die("No ELF magic\n"); + } + if (ehdr.e_ident[EI_CLASS] != ELFCLASS32) { + die("Not a 32 bit executable\n"); + } + if (ehdr.e_ident[EI_DATA] != ELFDATA2LSB) { + die("Not a LSB ELF executable\n"); + } + if (ehdr.e_ident[EI_VERSION] != EV_CURRENT) { + die("Unknown ELF version\n"); + } + /* Convert the fields to native endian */ + ehdr.e_type = elf16_to_cpu(ehdr.e_type); + ehdr.e_machine = elf16_to_cpu(ehdr.e_machine); + ehdr.e_version = elf32_to_cpu(ehdr.e_version); + ehdr.e_entry = elf32_to_cpu(ehdr.e_entry); + ehdr.e_phoff = elf32_to_cpu(ehdr.e_phoff); + ehdr.e_shoff = elf32_to_cpu(ehdr.e_shoff); + ehdr.e_flags = elf32_to_cpu(ehdr.e_flags); + ehdr.e_ehsize = elf16_to_cpu(ehdr.e_ehsize); + ehdr.e_phentsize = elf16_to_cpu(ehdr.e_phentsize); + ehdr.e_phnum = elf16_to_cpu(ehdr.e_phnum); + ehdr.e_shentsize = elf16_to_cpu(ehdr.e_shentsize); + ehdr.e_shnum = elf16_to_cpu(ehdr.e_shnum); + ehdr.e_shstrndx = elf16_to_cpu(ehdr.e_shstrndx); + + if ((ehdr.e_type != ET_EXEC) && (ehdr.e_type != ET_DYN)) { + die("Unsupported ELF header type\n"); + } + if (ehdr.e_machine != EM_386) { + die("Not for x86\n"); + } + if (ehdr.e_version != EV_CURRENT) { + die("Unknown ELF version\n"); + } + if (ehdr.e_ehsize != sizeof(Elf32_Ehdr)) { + die("Bad Elf header size\n"); + } + if (ehdr.e_phentsize != sizeof(Elf32_Phdr)) { + die("Bad program header entry\n"); + } + if (ehdr.e_shentsize != sizeof(Elf32_Shdr)) { + die("Bad section header entry\n"); + } + if (ehdr.e_shstrndx >= ehdr.e_shnum) { + die("String table index out of bounds\n"); + } +} + +static void read_shdrs(FILE *fp) +{ + int i; + if (ehdr.e_shnum > MAX_SHDRS) { + die("%d section headers supported: %d\n", + ehdr.e_shnum, MAX_SHDRS); + } + if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0) { + die("Seek to %d failed: %s\n", + ehdr.e_shoff, strerror(errno)); + } + if (fread(&shdr, sizeof(shdr[0]), ehdr.e_shnum, fp) != ehdr.e_shnum) { + die("Cannot read ELF section headers: %s\n", + strerror(errno)); + } + for(i = 0; i < ehdr.e_shnum; i++) { + shdr[i].sh_name = elf32_to_cpu(shdr[i].sh_name); + shdr[i].sh_type = elf32_to_cpu(shdr[i].sh_type); + shdr[i].sh_flags = elf32_to_cpu(shdr[i].sh_flags); + shdr[i].sh_addr = elf32_to_cpu(shdr[i].sh_addr); + shdr[i].sh_offset = elf32_to_cpu(shdr[i].sh_offset); + shdr[i].sh_size = elf32_to_cpu(shdr[i].sh_size); + shdr[i].sh_link = elf32_to_cpu(shdr[i].sh_link); + shdr[i].sh_info = elf32_to_cpu(shdr[i].sh_info); + shdr[i].sh_addralign = elf32_to_cpu(shdr[i].sh_addralign); + shdr[i].sh_entsize = elf32_to_cpu(shdr[i].sh_entsize); + } + +} + +static void read_strtabs(FILE *fp) +{ + int i; + for(i = 0; i < ehdr.e_shnum; i++) { + if (shdr[i].sh_type != SHT_STRTAB) { + continue; + } + strtab[i] = malloc(shdr[i].sh_size); + if (!strtab[i]) { + die("malloc of %d bytes for strtab failed\n", + shdr[i].sh_size); + } + if (fseek(fp, shdr[i].sh_offset, SEEK_SET) < 0) { + die("Seek to %d failed: %s\n", + shdr[i].sh_offset, strerror(errno)); + } + if (fread(strtab[i], 1, shdr[i].sh_size, fp) != shdr[i].sh_size) { + die("Cannot read symbol table: %s\n", + strerror(errno)); + } + } +} + +static void read_symtabs(FILE *fp) +{ + int i,j; + for(i = 0; i < ehdr.e_shnum; i++) { + if (shdr[i].sh_type != SHT_SYMTAB) { + continue; + } + symtab[i] = malloc(shdr[i].sh_size); + if (!symtab[i]) { + die("malloc of %d bytes for symtab failed\n", + shdr[i].sh_size); + } + if (fseek(fp, shdr[i].sh_offset, SEEK_SET) < 0) { + die("Seek to %d failed: %s\n", + shdr[i].sh_offset, strerror(errno)); + } + if (fread(symtab[i], 1, shdr[i].sh_size, fp) != shdr[i].sh_size) { + die("Cannot read symbol table: %s\n", + strerror(errno)); + } + for(j = 0; j < shdr[i].sh_size/sizeof(symtab[i][0]); j++) { + symtab[i][j].st_name = elf32_to_cpu(symtab[i][j].st_name); + symtab[i][j].st_value = elf32_to_cpu(symtab[i][j].st_value); + symtab[i][j].st_size = elf32_to_cpu(symtab[i][j].st_size); + symtab[i][j].st_shndx = elf16_to_cpu(symtab[i][j].st_shndx); + } + } +} + + +static void read_relocs(FILE *fp) +{ + int i,j; + for(i = 0; i < ehdr.e_shnum; i++) { + if (shdr[i].sh_type != SHT_REL) { + continue; + } + reltab[i] = malloc(shdr[i].sh_size); + if (!reltab[i]) { + die("malloc of %d bytes for relocs failed\n", + shdr[i].sh_size); + } + if (fseek(fp, shdr[i].sh_offset, SEEK_SET) < 0) { + die("Seek to %d failed: %s\n", + shdr[i].sh_offset, strerror(errno)); + } + if (fread(reltab[i], 1, shdr[i].sh_size, fp) != shdr[i].sh_size) { + die("Cannot read symbol table: %s\n", + strerror(errno)); + } + for(j = 0; j < shdr[i].sh_size/sizeof(reltab[0][0]); j++) { + reltab[i][j].r_offset = elf32_to_cpu(reltab[i][j].r_offset); + reltab[i][j].r_info = elf32_to_cpu(reltab[i][j].r_info); + } + } +} + + +static void print_absolute_symbols(void) +{ + int i; + printf("Absolute symbols\n"); + printf(" Num: Value Size Type Bind Visibility Name\n"); + for(i = 0; i < ehdr.e_shnum; i++) { + char *sym_strtab; + Elf32_Sym *sh_symtab; + int j; + if (shdr[i].sh_type != SHT_SYMTAB) { + continue; + } + sh_symtab = symtab[i]; + sym_strtab = strtab[shdr[i].sh_link]; + for(j = 0; j < shdr[i].sh_size/sizeof(symtab[0][0]); j++) { + Elf32_Sym *sym; + const char *name; + sym = &symtab[i][j]; + name = sym_name(sym_strtab, sym); + if (sym->st_shndx != SHN_ABS) { + continue; + } + printf("%5d %08x %5d %10s %10s %12s %s\n", + j, sym->st_value, sym->st_size, + sym_type(ELF32_ST_TYPE(sym->st_info)), + sym_bind(ELF32_ST_BIND(sym->st_info)), + sym_visibility(ELF32_ST_VISIBILITY(sym->st_other)), + name); + } + } + printf("\n"); +} + +static void print_absolute_relocs(void) +{ + int i, printed = 0; + + for(i = 0; i < ehdr.e_shnum; i++) { + char *sym_strtab; + Elf32_Sym *sh_symtab; + unsigned sec_applies, sec_symtab; + int j; + if (shdr[i].sh_type != SHT_REL) { + continue; + } + sec_symtab = shdr[i].sh_link; + sec_applies = shdr[i].sh_info; + if (!(shdr[sec_applies].sh_flags & SHF_ALLOC)) { + continue; + } + sh_symtab = symtab[sec_symtab]; + sym_strtab = strtab[shdr[sec_symtab].sh_link]; + for(j = 0; j < shdr[i].sh_size/sizeof(reltab[0][0]); j++) { + Elf32_Rel *rel; + Elf32_Sym *sym; + const char *name; + rel = &reltab[i][j]; + sym = &sh_symtab[ELF32_R_SYM(rel->r_info)]; + name = sym_name(sym_strtab, sym); + if (sym->st_shndx != SHN_ABS) { + continue; + } + + /* Absolute symbols are not relocated if bzImage is + * loaded at a non-compiled address. Display a warning + * to user at compile time about the absolute + * relocations present. + * + * User need to audit the code to make sure + * some symbols which should have been section + * relative have not become absolute because of some + * linker optimization or wrong programming usage. + * + * Before warning check if this absolute symbol + * relocation is harmless. + */ + if (is_safe_abs_reloc(name)) + continue; + + if (!printed) { + printf("WARNING: Absolute relocations" + " present\n"); + printf("Offset Info Type Sym.Value " + "Sym.Name\n"); + printed = 1; + } + + printf("%08x %08x %10s %08x %s\n", + rel->r_offset, + rel->r_info, + rel_type(ELF32_R_TYPE(rel->r_info)), + sym->st_value, + name); + } + } + + if (printed) + printf("\n"); +} + +static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym)) +{ + int i; + /* Walk through the relocations */ + for(i = 0; i < ehdr.e_shnum; i++) { + char *sym_strtab; + Elf32_Sym *sh_symtab; + unsigned sec_applies, sec_symtab; + int j; + if (shdr[i].sh_type != SHT_REL) { + continue; + } + sec_symtab = shdr[i].sh_link; + sec_applies = shdr[i].sh_info; + if (!(shdr[sec_applies].sh_flags & SHF_ALLOC)) { + continue; + } + sh_symtab = symtab[sec_symtab]; + sym_strtab = strtab[shdr[sec_symtab].sh_link]; + for(j = 0; j < shdr[i].sh_size/sizeof(reltab[0][0]); j++) { + Elf32_Rel *rel; + Elf32_Sym *sym; + unsigned r_type; + rel = &reltab[i][j]; + sym = &sh_symtab[ELF32_R_SYM(rel->r_info)]; + r_type = ELF32_R_TYPE(rel->r_info); + /* Don't visit relocations to absolute symbols */ + if (sym->st_shndx == SHN_ABS) { + continue; + } + if (r_type == R_386_PC32) { + /* PC relative relocations don't need to be adjusted */ + } + else if (r_type == R_386_32) { + /* Visit relocations that need to be adjusted */ + visit(rel, sym); + } + else { + die("Unsupported relocation type: %d\n", r_type); + } + } + } +} + +static void count_reloc(Elf32_Rel *rel, Elf32_Sym *sym) +{ + reloc_count += 1; +} + +static void collect_reloc(Elf32_Rel *rel, Elf32_Sym *sym) +{ + /* Remember the address that needs to be adjusted. */ + relocs[reloc_idx++] = rel->r_offset; +} + +static int cmp_relocs(const void *va, const void *vb) +{ + const unsigned long *a, *b; + a = va; b = vb; + return (*a == *b)? 0 : (*a > *b)? 1 : -1; +} + +static void emit_relocs(int as_text) +{ + int i; + /* Count how many relocations I have and allocate space for them. */ + reloc_count = 0; + walk_relocs(count_reloc); + relocs = malloc(reloc_count * sizeof(relocs[0])); + if (!relocs) { + die("malloc of %d entries for relocs failed\n", + reloc_count); + } + /* Collect up the relocations */ + reloc_idx = 0; + walk_relocs(collect_reloc); + + /* Order the relocations for more efficient processing */ + qsort(relocs, reloc_count, sizeof(relocs[0]), cmp_relocs); + + /* Print the relocations */ + if (as_text) { + /* Print the relocations in a form suitable that + * gas will like. + */ + printf(".section \".data.reloc\",\"a\"\n"); + printf(".balign 4\n"); + for(i = 0; i < reloc_count; i++) { + printf("\t .long 0x%08lx\n", relocs[i]); + } + printf("\n"); + } + else { + unsigned char buf[4]; + buf[0] = buf[1] = buf[2] = buf[3] = 0; + /* Print a stop */ + printf("%c%c%c%c", buf[0], buf[1], buf[2], buf[3]); + /* Now print each relocation */ + for(i = 0; i < reloc_count; i++) { + buf[0] = (relocs[i] >> 0) & 0xff; + buf[1] = (relocs[i] >> 8) & 0xff; + buf[2] = (relocs[i] >> 16) & 0xff; + buf[3] = (relocs[i] >> 24) & 0xff; + printf("%c%c%c%c", buf[0], buf[1], buf[2], buf[3]); + } + } +} + +static void usage(void) +{ + die("relocs [--abs-syms |--abs-relocs | --text] vmlinux\n"); +} + +int main(int argc, char **argv) +{ + int show_absolute_syms, show_absolute_relocs; + int as_text; + const char *fname; + FILE *fp; + int i; + + show_absolute_syms = 0; + show_absolute_relocs = 0; + as_text = 0; + fname = NULL; + for(i = 1; i < argc; i++) { + char *arg = argv[i]; + if (*arg == '-') { + if (strcmp(argv[1], "--abs-syms") == 0) { + show_absolute_syms = 1; + continue; + } + + if (strcmp(argv[1], "--abs-relocs") == 0) { + show_absolute_relocs = 1; + continue; + } + else if (strcmp(argv[1], "--text") == 0) { + as_text = 1; + continue; + } + } + else if (!fname) { + fname = arg; + continue; + } + usage(); + } + if (!fname) { + usage(); + } + fp = fopen(fname, "r"); + if (!fp) { + die("Cannot open %s: %s\n", + fname, strerror(errno)); + } + read_ehdr(fp); + read_shdrs(fp); + read_strtabs(fp); + read_symtabs(fp); + read_relocs(fp); + if (show_absolute_syms) { + print_absolute_symbols(); + return 0; + } + if (show_absolute_relocs) { + print_absolute_relocs(); + return 0; + } + emit_relocs(as_text); + return 0; +} diff --git a/arch/i386/boot/compressed/vmlinux.lds b/arch/i386/boot/compressed/vmlinux.lds new file mode 100644 index 00000000000..cc4854f6c6c --- /dev/null +++ b/arch/i386/boot/compressed/vmlinux.lds @@ -0,0 +1,43 @@ +OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386") +OUTPUT_ARCH(i386) +ENTRY(startup_32) +SECTIONS +{ + /* Be careful parts of head.S assume startup_32 is at + * address 0. + */ + . = 0 ; + .text.head : { + _head = . ; + *(.text.head) + _ehead = . ; + } + .data.compressed : { + *(.data.compressed) + } + .text : { + _text = .; /* Text */ + *(.text) + *(.text.*) + _etext = . ; + } + .rodata : { + _rodata = . ; + *(.rodata) /* read-only data */ + *(.rodata.*) + _erodata = . ; + } + .data : { + _data = . ; + *(.data) + *(.data.*) + _edata = . ; + } + .bss : { + _bss = . ; + *(.bss) + *(.bss.*) + *(COMMON) + _end = . ; + } +} diff --git a/arch/i386/boot/compressed/vmlinux.scr b/arch/i386/boot/compressed/vmlinux.scr index 1ed9d791f86..707a88f7f29 100644 --- a/arch/i386/boot/compressed/vmlinux.scr +++ b/arch/i386/boot/compressed/vmlinux.scr @@ -1,9 +1,10 @@ SECTIONS { - .data : { + .data.compressed : { input_len = .; LONG(input_data_end - input_data) input_data = .; *(.data) + output_len = . - 4; input_data_end = .; } } |