x86, realmode: 16-bit real-mode code support for relocs tool
A new option is added to the relocs tool called '--realmode'. This option causes the generation of 16-bit segment relocations and 32-bit linear relocations for the real-mode code. When the real-mode code is moved to the low-memory during kernel initialization, these relocation entries can be used to relocate the code properly. In the assembly code 16-bit segment relocations must be relative to the 'real_mode_seg' absolute symbol. Linear relocations must be relative to a symbol prefixed with 'pa_'. 16-bit segment relocation is used to load cs:ip in 16-bit code. Linear relocations are used in the 32-bit code for relocatable data references. They are declared in the linker script of the real-mode code. The relocs tool is moved to arch/x86/tools/relocs.c, and added new target archscripts that can be used to build scripts needed building an architecture. be compiled before building the arch/x86 tree. [ hpa: accelerating this because it detects invalid absolute relocations, a serious bug in binutils 2.22.52.0.x which currently produces bad kernels. ] Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Link: http://lkml.kernel.org/r/1336501366-28617-2-git-send-email-jarkko.sakkinen@intel.com Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: <stable@vger.kernel.org>
This commit is contained in:
H. Peter Anvin
797
arch/x86/tools/relocs.c
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797
arch/x86/tools/relocs.c
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@@ -0,0 +1,797 @@
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#include <stdio.h>
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#include <stdarg.h>
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#include <stdlib.h>
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#include <stdint.h>
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#include <string.h>
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#include <errno.h>
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#include <unistd.h>
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#include <elf.h>
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#include <byteswap.h>
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#define USE_BSD
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#include <endian.h>
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#include <regex.h>
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#include <tools/le_byteshift.h>
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static void die(char *fmt, ...);
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#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
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static Elf32_Ehdr ehdr;
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static unsigned long reloc_count, reloc_idx;
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static unsigned long *relocs;
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static unsigned long reloc16_count, reloc16_idx;
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static unsigned long *relocs16;
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struct section {
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Elf32_Shdr shdr;
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struct section *link;
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Elf32_Sym *symtab;
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Elf32_Rel *reltab;
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char *strtab;
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};
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static struct section *secs;
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enum symtype {
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S_ABS,
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S_REL,
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S_SEG,
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S_LIN,
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S_NSYMTYPES
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};
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static const char * const sym_regex_kernel[S_NSYMTYPES] = {
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/*
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* Following symbols have been audited. There values are constant and do
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* not change if bzImage is loaded at a different physical address than
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* the address for which it has been compiled. Don't warn user about
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* absolute relocations present w.r.t these symbols.
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*/
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[S_ABS] =
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"^(xen_irq_disable_direct_reloc$|"
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"xen_save_fl_direct_reloc$|"
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"VDSO|"
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"__crc_)",
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/*
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* These symbols are known to be relative, even if the linker marks them
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* as absolute (typically defined outside any section in the linker script.)
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*/
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[S_REL] =
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"^_end$",
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};
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static const char * const sym_regex_realmode[S_NSYMTYPES] = {
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/*
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* These are 16-bit segment symbols when compiling 16-bit code.
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*/
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[S_SEG] =
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"^real_mode_seg$",
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/*
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* These are offsets belonging to segments, as opposed to linear addresses,
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* when compiling 16-bit code.
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*/
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[S_LIN] =
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"^pa_",
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};
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static const char * const *sym_regex;
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static regex_t sym_regex_c[S_NSYMTYPES];
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static int is_reloc(enum symtype type, const char *sym_name)
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{
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return sym_regex[type] &&
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!regexec(&sym_regex_c[type], sym_name, 0, NULL, 0);
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}
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static void regex_init(int use_real_mode)
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{
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char errbuf[128];
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int err;
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int i;
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if (use_real_mode)
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sym_regex = sym_regex_realmode;
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else
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sym_regex = sym_regex_kernel;
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for (i = 0; i < S_NSYMTYPES; i++) {
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if (!sym_regex[i])
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continue;
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err = regcomp(&sym_regex_c[i], sym_regex[i],
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REG_EXTENDED|REG_NOSUB);
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if (err) {
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regerror(err, &sym_regex_c[i], errbuf, sizeof errbuf);
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die("%s", errbuf);
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}
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}
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}
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static void die(char *fmt, ...)
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{
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va_list ap;
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va_start(ap, fmt);
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vfprintf(stderr, fmt, ap);
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va_end(ap);
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exit(1);
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}
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static const char *sym_type(unsigned type)
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{
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static const char *type_name[] = {
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#define SYM_TYPE(X) [X] = #X
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SYM_TYPE(STT_NOTYPE),
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SYM_TYPE(STT_OBJECT),
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SYM_TYPE(STT_FUNC),
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SYM_TYPE(STT_SECTION),
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SYM_TYPE(STT_FILE),
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SYM_TYPE(STT_COMMON),
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SYM_TYPE(STT_TLS),
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#undef SYM_TYPE
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};
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const char *name = "unknown sym type name";
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if (type < ARRAY_SIZE(type_name)) {
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name = type_name[type];
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}
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return name;
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}
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static const char *sym_bind(unsigned bind)
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{
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static const char *bind_name[] = {
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#define SYM_BIND(X) [X] = #X
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SYM_BIND(STB_LOCAL),
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SYM_BIND(STB_GLOBAL),
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SYM_BIND(STB_WEAK),
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#undef SYM_BIND
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};
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const char *name = "unknown sym bind name";
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if (bind < ARRAY_SIZE(bind_name)) {
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name = bind_name[bind];
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}
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return name;
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}
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static const char *sym_visibility(unsigned visibility)
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{
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static const char *visibility_name[] = {
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#define SYM_VISIBILITY(X) [X] = #X
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SYM_VISIBILITY(STV_DEFAULT),
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SYM_VISIBILITY(STV_INTERNAL),
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SYM_VISIBILITY(STV_HIDDEN),
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SYM_VISIBILITY(STV_PROTECTED),
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#undef SYM_VISIBILITY
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};
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const char *name = "unknown sym visibility name";
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if (visibility < ARRAY_SIZE(visibility_name)) {
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name = visibility_name[visibility];
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}
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return name;
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}
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static const char *rel_type(unsigned type)
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{
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static const char *type_name[] = {
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#define REL_TYPE(X) [X] = #X
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REL_TYPE(R_386_NONE),
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REL_TYPE(R_386_32),
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REL_TYPE(R_386_PC32),
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REL_TYPE(R_386_GOT32),
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REL_TYPE(R_386_PLT32),
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REL_TYPE(R_386_COPY),
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REL_TYPE(R_386_GLOB_DAT),
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REL_TYPE(R_386_JMP_SLOT),
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REL_TYPE(R_386_RELATIVE),
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REL_TYPE(R_386_GOTOFF),
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REL_TYPE(R_386_GOTPC),
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REL_TYPE(R_386_8),
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REL_TYPE(R_386_PC8),
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REL_TYPE(R_386_16),
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REL_TYPE(R_386_PC16),
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#undef REL_TYPE
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};
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const char *name = "unknown type rel type name";
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if (type < ARRAY_SIZE(type_name) && type_name[type]) {
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name = type_name[type];
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}
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return name;
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}
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static const char *sec_name(unsigned shndx)
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{
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const char *sec_strtab;
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const char *name;
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sec_strtab = secs[ehdr.e_shstrndx].strtab;
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name = "<noname>";
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if (shndx < ehdr.e_shnum) {
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name = sec_strtab + secs[shndx].shdr.sh_name;
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}
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else if (shndx == SHN_ABS) {
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name = "ABSOLUTE";
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}
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else if (shndx == SHN_COMMON) {
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name = "COMMON";
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}
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return name;
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}
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static const char *sym_name(const char *sym_strtab, Elf32_Sym *sym)
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{
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const char *name;
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name = "<noname>";
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if (sym->st_name) {
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name = sym_strtab + sym->st_name;
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}
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else {
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name = sec_name(sym->st_shndx);
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}
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return name;
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}
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#if BYTE_ORDER == LITTLE_ENDIAN
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#define le16_to_cpu(val) (val)
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#define le32_to_cpu(val) (val)
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#endif
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#if BYTE_ORDER == BIG_ENDIAN
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#define le16_to_cpu(val) bswap_16(val)
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#define le32_to_cpu(val) bswap_32(val)
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#endif
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static uint16_t elf16_to_cpu(uint16_t val)
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{
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return le16_to_cpu(val);
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}
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static uint32_t elf32_to_cpu(uint32_t val)
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{
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return le32_to_cpu(val);
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}
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static void read_ehdr(FILE *fp)
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{
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if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1) {
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die("Cannot read ELF header: %s\n",
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strerror(errno));
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}
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if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0) {
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die("No ELF magic\n");
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}
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if (ehdr.e_ident[EI_CLASS] != ELFCLASS32) {
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die("Not a 32 bit executable\n");
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}
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if (ehdr.e_ident[EI_DATA] != ELFDATA2LSB) {
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die("Not a LSB ELF executable\n");
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}
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if (ehdr.e_ident[EI_VERSION] != EV_CURRENT) {
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die("Unknown ELF version\n");
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}
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/* Convert the fields to native endian */
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ehdr.e_type = elf16_to_cpu(ehdr.e_type);
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ehdr.e_machine = elf16_to_cpu(ehdr.e_machine);
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ehdr.e_version = elf32_to_cpu(ehdr.e_version);
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ehdr.e_entry = elf32_to_cpu(ehdr.e_entry);
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ehdr.e_phoff = elf32_to_cpu(ehdr.e_phoff);
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ehdr.e_shoff = elf32_to_cpu(ehdr.e_shoff);
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ehdr.e_flags = elf32_to_cpu(ehdr.e_flags);
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ehdr.e_ehsize = elf16_to_cpu(ehdr.e_ehsize);
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ehdr.e_phentsize = elf16_to_cpu(ehdr.e_phentsize);
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ehdr.e_phnum = elf16_to_cpu(ehdr.e_phnum);
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ehdr.e_shentsize = elf16_to_cpu(ehdr.e_shentsize);
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ehdr.e_shnum = elf16_to_cpu(ehdr.e_shnum);
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ehdr.e_shstrndx = elf16_to_cpu(ehdr.e_shstrndx);
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if ((ehdr.e_type != ET_EXEC) && (ehdr.e_type != ET_DYN)) {
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die("Unsupported ELF header type\n");
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}
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if (ehdr.e_machine != EM_386) {
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die("Not for x86\n");
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}
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if (ehdr.e_version != EV_CURRENT) {
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die("Unknown ELF version\n");
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}
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if (ehdr.e_ehsize != sizeof(Elf32_Ehdr)) {
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die("Bad Elf header size\n");
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}
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if (ehdr.e_phentsize != sizeof(Elf32_Phdr)) {
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die("Bad program header entry\n");
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}
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if (ehdr.e_shentsize != sizeof(Elf32_Shdr)) {
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die("Bad section header entry\n");
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}
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if (ehdr.e_shstrndx >= ehdr.e_shnum) {
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die("String table index out of bounds\n");
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}
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}
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static void read_shdrs(FILE *fp)
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{
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int i;
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Elf32_Shdr shdr;
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secs = calloc(ehdr.e_shnum, sizeof(struct section));
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if (!secs) {
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die("Unable to allocate %d section headers\n",
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ehdr.e_shnum);
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}
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if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0) {
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die("Seek to %d failed: %s\n",
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ehdr.e_shoff, strerror(errno));
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}
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for (i = 0; i < ehdr.e_shnum; i++) {
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struct section *sec = &secs[i];
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if (fread(&shdr, sizeof shdr, 1, fp) != 1)
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die("Cannot read ELF section headers %d/%d: %s\n",
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i, ehdr.e_shnum, strerror(errno));
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sec->shdr.sh_name = elf32_to_cpu(shdr.sh_name);
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sec->shdr.sh_type = elf32_to_cpu(shdr.sh_type);
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sec->shdr.sh_flags = elf32_to_cpu(shdr.sh_flags);
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sec->shdr.sh_addr = elf32_to_cpu(shdr.sh_addr);
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sec->shdr.sh_offset = elf32_to_cpu(shdr.sh_offset);
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sec->shdr.sh_size = elf32_to_cpu(shdr.sh_size);
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sec->shdr.sh_link = elf32_to_cpu(shdr.sh_link);
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sec->shdr.sh_info = elf32_to_cpu(shdr.sh_info);
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sec->shdr.sh_addralign = elf32_to_cpu(shdr.sh_addralign);
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sec->shdr.sh_entsize = elf32_to_cpu(shdr.sh_entsize);
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if (sec->shdr.sh_link < ehdr.e_shnum)
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sec->link = &secs[sec->shdr.sh_link];
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}
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}
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static void read_strtabs(FILE *fp)
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{
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int i;
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for (i = 0; i < ehdr.e_shnum; i++) {
|
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struct section *sec = &secs[i];
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if (sec->shdr.sh_type != SHT_STRTAB) {
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continue;
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}
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sec->strtab = malloc(sec->shdr.sh_size);
|
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if (!sec->strtab) {
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die("malloc of %d bytes for strtab failed\n",
|
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sec->shdr.sh_size);
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}
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if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
|
||||
die("Seek to %d failed: %s\n",
|
||||
sec->shdr.sh_offset, strerror(errno));
|
||||
}
|
||||
if (fread(sec->strtab, 1, sec->shdr.sh_size, fp)
|
||||
!= sec->shdr.sh_size) {
|
||||
die("Cannot read symbol table: %s\n",
|
||||
strerror(errno));
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
static void read_symtabs(FILE *fp)
|
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{
|
||||
int i,j;
|
||||
for (i = 0; i < ehdr.e_shnum; i++) {
|
||||
struct section *sec = &secs[i];
|
||||
if (sec->shdr.sh_type != SHT_SYMTAB) {
|
||||
continue;
|
||||
}
|
||||
sec->symtab = malloc(sec->shdr.sh_size);
|
||||
if (!sec->symtab) {
|
||||
die("malloc of %d bytes for symtab failed\n",
|
||||
sec->shdr.sh_size);
|
||||
}
|
||||
if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
|
||||
die("Seek to %d failed: %s\n",
|
||||
sec->shdr.sh_offset, strerror(errno));
|
||||
}
|
||||
if (fread(sec->symtab, 1, sec->shdr.sh_size, fp)
|
||||
!= sec->shdr.sh_size) {
|
||||
die("Cannot read symbol table: %s\n",
|
||||
strerror(errno));
|
||||
}
|
||||
for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Sym); j++) {
|
||||
Elf32_Sym *sym = &sec->symtab[j];
|
||||
sym->st_name = elf32_to_cpu(sym->st_name);
|
||||
sym->st_value = elf32_to_cpu(sym->st_value);
|
||||
sym->st_size = elf32_to_cpu(sym->st_size);
|
||||
sym->st_shndx = elf16_to_cpu(sym->st_shndx);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
static void read_relocs(FILE *fp)
|
||||
{
|
||||
int i,j;
|
||||
for (i = 0; i < ehdr.e_shnum; i++) {
|
||||
struct section *sec = &secs[i];
|
||||
if (sec->shdr.sh_type != SHT_REL) {
|
||||
continue;
|
||||
}
|
||||
sec->reltab = malloc(sec->shdr.sh_size);
|
||||
if (!sec->reltab) {
|
||||
die("malloc of %d bytes for relocs failed\n",
|
||||
sec->shdr.sh_size);
|
||||
}
|
||||
if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
|
||||
die("Seek to %d failed: %s\n",
|
||||
sec->shdr.sh_offset, strerror(errno));
|
||||
}
|
||||
if (fread(sec->reltab, 1, sec->shdr.sh_size, fp)
|
||||
!= sec->shdr.sh_size) {
|
||||
die("Cannot read symbol table: %s\n",
|
||||
strerror(errno));
|
||||
}
|
||||
for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Rel); j++) {
|
||||
Elf32_Rel *rel = &sec->reltab[j];
|
||||
rel->r_offset = elf32_to_cpu(rel->r_offset);
|
||||
rel->r_info = elf32_to_cpu(rel->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++) {
|
||||
struct section *sec = &secs[i];
|
||||
char *sym_strtab;
|
||||
int j;
|
||||
|
||||
if (sec->shdr.sh_type != SHT_SYMTAB) {
|
||||
continue;
|
||||
}
|
||||
sym_strtab = sec->link->strtab;
|
||||
for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Sym); j++) {
|
||||
Elf32_Sym *sym;
|
||||
const char *name;
|
||||
sym = &sec->symtab[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++) {
|
||||
struct section *sec = &secs[i];
|
||||
struct section *sec_applies, *sec_symtab;
|
||||
char *sym_strtab;
|
||||
Elf32_Sym *sh_symtab;
|
||||
int j;
|
||||
if (sec->shdr.sh_type != SHT_REL) {
|
||||
continue;
|
||||
}
|
||||
sec_symtab = sec->link;
|
||||
sec_applies = &secs[sec->shdr.sh_info];
|
||||
if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) {
|
||||
continue;
|
||||
}
|
||||
sh_symtab = sec_symtab->symtab;
|
||||
sym_strtab = sec_symtab->link->strtab;
|
||||
for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Rel); j++) {
|
||||
Elf32_Rel *rel;
|
||||
Elf32_Sym *sym;
|
||||
const char *name;
|
||||
rel = &sec->reltab[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_reloc(S_ABS, name) || is_reloc(S_REL, 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 use_real_mode)
|
||||
{
|
||||
int i;
|
||||
/* Walk through the relocations */
|
||||
for (i = 0; i < ehdr.e_shnum; i++) {
|
||||
char *sym_strtab;
|
||||
Elf32_Sym *sh_symtab;
|
||||
struct section *sec_applies, *sec_symtab;
|
||||
int j;
|
||||
struct section *sec = &secs[i];
|
||||
|
||||
if (sec->shdr.sh_type != SHT_REL) {
|
||||
continue;
|
||||
}
|
||||
sec_symtab = sec->link;
|
||||
sec_applies = &secs[sec->shdr.sh_info];
|
||||
if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) {
|
||||
continue;
|
||||
}
|
||||
sh_symtab = sec_symtab->symtab;
|
||||
sym_strtab = sec_symtab->link->strtab;
|
||||
for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Rel); j++) {
|
||||
Elf32_Rel *rel;
|
||||
Elf32_Sym *sym;
|
||||
unsigned r_type;
|
||||
const char *symname;
|
||||
rel = &sec->reltab[j];
|
||||
sym = &sh_symtab[ELF32_R_SYM(rel->r_info)];
|
||||
r_type = ELF32_R_TYPE(rel->r_info);
|
||||
|
||||
switch (r_type) {
|
||||
case R_386_NONE:
|
||||
case R_386_PC32:
|
||||
case R_386_PC16:
|
||||
case R_386_PC8:
|
||||
/*
|
||||
* NONE can be ignored and and PC relative
|
||||
* relocations don't need to be adjusted.
|
||||
*/
|
||||
break;
|
||||
|
||||
case R_386_16:
|
||||
symname = sym_name(sym_strtab, sym);
|
||||
if (!use_real_mode)
|
||||
goto bad;
|
||||
if (sym->st_shndx == SHN_ABS) {
|
||||
if (is_reloc(S_ABS, symname))
|
||||
break;
|
||||
else if (!is_reloc(S_SEG, symname))
|
||||
goto bad;
|
||||
} else {
|
||||
if (is_reloc(S_LIN, symname))
|
||||
goto bad;
|
||||
else
|
||||
break;
|
||||
}
|
||||
visit(rel, sym);
|
||||
break;
|
||||
|
||||
case R_386_32:
|
||||
symname = sym_name(sym_strtab, sym);
|
||||
if (sym->st_shndx == SHN_ABS) {
|
||||
if (is_reloc(S_ABS, symname))
|
||||
break;
|
||||
else if (!is_reloc(S_REL, symname))
|
||||
goto bad;
|
||||
} else {
|
||||
if (use_real_mode &&
|
||||
!is_reloc(S_LIN, symname))
|
||||
break;
|
||||
}
|
||||
visit(rel, sym);
|
||||
break;
|
||||
default:
|
||||
die("Unsupported relocation type: %s (%d)\n",
|
||||
rel_type(r_type), r_type);
|
||||
break;
|
||||
bad:
|
||||
symname = sym_name(sym_strtab, sym);
|
||||
die("Invalid %s relocation: %s\n",
|
||||
rel_type(r_type), symname);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
static void count_reloc(Elf32_Rel *rel, Elf32_Sym *sym)
|
||||
{
|
||||
if (ELF32_R_TYPE(rel->r_info) == R_386_16)
|
||||
reloc16_count++;
|
||||
else
|
||||
reloc_count++;
|
||||
}
|
||||
|
||||
static void collect_reloc(Elf32_Rel *rel, Elf32_Sym *sym)
|
||||
{
|
||||
/* Remember the address that needs to be adjusted. */
|
||||
if (ELF32_R_TYPE(rel->r_info) == R_386_16)
|
||||
relocs16[reloc16_idx++] = rel->r_offset;
|
||||
else
|
||||
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 int write32(unsigned int v, FILE *f)
|
||||
{
|
||||
unsigned char buf[4];
|
||||
|
||||
put_unaligned_le32(v, buf);
|
||||
return fwrite(buf, 1, 4, f) == 4 ? 0 : -1;
|
||||
}
|
||||
|
||||
static void emit_relocs(int as_text, int use_real_mode)
|
||||
{
|
||||
int i;
|
||||
/* Count how many relocations I have and allocate space for them. */
|
||||
reloc_count = 0;
|
||||
walk_relocs(count_reloc, use_real_mode);
|
||||
relocs = malloc(reloc_count * sizeof(relocs[0]));
|
||||
if (!relocs) {
|
||||
die("malloc of %d entries for relocs failed\n",
|
||||
reloc_count);
|
||||
}
|
||||
|
||||
relocs16 = malloc(reloc16_count * sizeof(relocs[0]));
|
||||
if (!relocs16) {
|
||||
die("malloc of %d entries for relocs16 failed\n",
|
||||
reloc16_count);
|
||||
}
|
||||
/* Collect up the relocations */
|
||||
reloc_idx = 0;
|
||||
walk_relocs(collect_reloc, use_real_mode);
|
||||
|
||||
if (reloc16_count && !use_real_mode)
|
||||
die("Segment relocations found but --realmode not specified\n");
|
||||
|
||||
/* Order the relocations for more efficient processing */
|
||||
qsort(relocs, reloc_count, sizeof(relocs[0]), cmp_relocs);
|
||||
qsort(relocs16, reloc16_count, sizeof(relocs16[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");
|
||||
if (use_real_mode) {
|
||||
printf("\t.long %lu\n", reloc16_count);
|
||||
for (i = 0; i < reloc16_count; i++)
|
||||
printf("\t.long 0x%08lx\n", relocs16[i]);
|
||||
printf("\t.long %lu\n", reloc_count);
|
||||
for (i = 0; i < reloc_count; i++) {
|
||||
printf("\t.long 0x%08lx\n", relocs[i]);
|
||||
}
|
||||
} else {
|
||||
/* Print a stop */
|
||||
printf("\t.long 0x%08lx\n", (unsigned long)0);
|
||||
for (i = 0; i < reloc_count; i++) {
|
||||
printf("\t.long 0x%08lx\n", relocs[i]);
|
||||
}
|
||||
}
|
||||
|
||||
printf("\n");
|
||||
}
|
||||
else {
|
||||
if (use_real_mode) {
|
||||
write32(reloc16_count, stdout);
|
||||
for (i = 0; i < reloc16_count; i++)
|
||||
write32(relocs16[i], stdout);
|
||||
write32(reloc_count, stdout);
|
||||
|
||||
/* Now print each relocation */
|
||||
for (i = 0; i < reloc_count; i++)
|
||||
write32(relocs[i], stdout);
|
||||
} else {
|
||||
/* Print a stop */
|
||||
write32(0, stdout);
|
||||
|
||||
/* Now print each relocation */
|
||||
for (i = 0; i < reloc_count; i++) {
|
||||
write32(relocs[i], stdout);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
static void usage(void)
|
||||
{
|
||||
die("relocs [--abs-syms|--abs-relocs|--text|--realmode] vmlinux\n");
|
||||
}
|
||||
|
||||
int main(int argc, char **argv)
|
||||
{
|
||||
int show_absolute_syms, show_absolute_relocs;
|
||||
int as_text, use_real_mode;
|
||||
const char *fname;
|
||||
FILE *fp;
|
||||
int i;
|
||||
|
||||
show_absolute_syms = 0;
|
||||
show_absolute_relocs = 0;
|
||||
as_text = 0;
|
||||
use_real_mode = 0;
|
||||
fname = NULL;
|
||||
for (i = 1; i < argc; i++) {
|
||||
char *arg = argv[i];
|
||||
if (*arg == '-') {
|
||||
if (strcmp(arg, "--abs-syms") == 0) {
|
||||
show_absolute_syms = 1;
|
||||
continue;
|
||||
}
|
||||
if (strcmp(arg, "--abs-relocs") == 0) {
|
||||
show_absolute_relocs = 1;
|
||||
continue;
|
||||
}
|
||||
if (strcmp(arg, "--text") == 0) {
|
||||
as_text = 1;
|
||||
continue;
|
||||
}
|
||||
if (strcmp(arg, "--realmode") == 0) {
|
||||
use_real_mode = 1;
|
||||
continue;
|
||||
}
|
||||
}
|
||||
else if (!fname) {
|
||||
fname = arg;
|
||||
continue;
|
||||
}
|
||||
usage();
|
||||
}
|
||||
if (!fname) {
|
||||
usage();
|
||||
}
|
||||
regex_init(use_real_mode);
|
||||
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, use_real_mode);
|
||||
return 0;
|
||||
}
|
||||
Reference in New Issue
Block a user