--- /dev/null
+/*
+ * sortextable.c: Sort the kernel's exception table
+ *
+ * Copyright 2011 - 2012 Cavium, Inc.
+ *
+ * Based on code taken from recortmcount.c which is:
+ *
+ * Copyright 2009 John F. Reiser <jreiser@BitWagon.com>. All rights reserved.
+ * Licensed under the GNU General Public License, version 2 (GPLv2).
+ *
+ * Restructured to fit Linux format, as well as other updates:
+ * Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.
+ */
+
+/*
+ * Strategy: alter the vmlinux file in-place.
+ */
+
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <getopt.h>
+#include <elf.h>
+#include <fcntl.h>
+#include <setjmp.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <tools/be_byteshift.h>
+#include <tools/le_byteshift.h>
+
+#ifndef EM_ARCOMPACT
+#define EM_ARCOMPACT 93
+#endif
+
+#ifndef EM_XTENSA
+#define EM_XTENSA 94
+#endif
+
+#ifndef EM_AARCH64
+#define EM_AARCH64 183
+#endif
+
+#ifndef EM_MICROBLAZE
+#define EM_MICROBLAZE 189
+#endif
+
+static int fd_map; /* File descriptor for file being modified. */
+static int mmap_failed; /* Boolean flag. */
+static void *ehdr_curr; /* current ElfXX_Ehdr * for resource cleanup */
+static struct stat sb; /* Remember .st_size, etc. */
+static jmp_buf jmpenv; /* setjmp/longjmp per-file error escape */
+
+/* setjmp() return values */
+enum {
+ SJ_SETJMP = 0, /* hardwired first return */
+ SJ_FAIL,
+ SJ_SUCCEED
+};
+
+/* Per-file resource cleanup when multiple files. */
+static void
+cleanup(void)
+{
+ if (!mmap_failed)
+ munmap(ehdr_curr, sb.st_size);
+ close(fd_map);
+}
+
+static void __attribute__((noreturn))
+fail_file(void)
+{
+ cleanup();
+ longjmp(jmpenv, SJ_FAIL);
+}
+
+/*
+ * Get the whole file as a programming convenience in order to avoid
+ * malloc+lseek+read+free of many pieces. If successful, then mmap
+ * avoids copying unused pieces; else just read the whole file.
+ * Open for both read and write.
+ */
+static void *mmap_file(char const *fname)
+{
+ void *addr;
+
+ fd_map = open(fname, O_RDWR);
+ if (fd_map < 0 || fstat(fd_map, &sb) < 0) {
+ perror(fname);
+ fail_file();
+ }
+ if (!S_ISREG(sb.st_mode)) {
+ fprintf(stderr, "not a regular file: %s\n", fname);
+ fail_file();
+ }
+ addr = mmap(0, sb.st_size, PROT_READ|PROT_WRITE, MAP_SHARED,
+ fd_map, 0);
+ if (addr == MAP_FAILED) {
+ mmap_failed = 1;
+ fprintf(stderr, "Could not mmap file: %s\n", fname);
+ fail_file();
+ }
+ return addr;
+}
+
+static uint64_t r8be(const uint64_t *x)
+{
+ return get_unaligned_be64(x);
+}
+static uint32_t rbe(const uint32_t *x)
+{
+ return get_unaligned_be32(x);
+}
+static uint16_t r2be(const uint16_t *x)
+{
+ return get_unaligned_be16(x);
+}
+static uint64_t r8le(const uint64_t *x)
+{
+ return get_unaligned_le64(x);
+}
+static uint32_t rle(const uint32_t *x)
+{
+ return get_unaligned_le32(x);
+}
+static uint16_t r2le(const uint16_t *x)
+{
+ return get_unaligned_le16(x);
+}
+
+static void w8be(uint64_t val, uint64_t *x)
+{
+ put_unaligned_be64(val, x);
+}
+static void wbe(uint32_t val, uint32_t *x)
+{
+ put_unaligned_be32(val, x);
+}
+static void w2be(uint16_t val, uint16_t *x)
+{
+ put_unaligned_be16(val, x);
+}
+static void w8le(uint64_t val, uint64_t *x)
+{
+ put_unaligned_le64(val, x);
+}
+static void wle(uint32_t val, uint32_t *x)
+{
+ put_unaligned_le32(val, x);
+}
+static void w2le(uint16_t val, uint16_t *x)
+{
+ put_unaligned_le16(val, x);
+}
+
+static uint64_t (*r8)(const uint64_t *);
+static uint32_t (*r)(const uint32_t *);
+static uint16_t (*r2)(const uint16_t *);
+static void (*w8)(uint64_t, uint64_t *);
+static void (*w)(uint32_t, uint32_t *);
+static void (*w2)(uint16_t, uint16_t *);
+
+typedef void (*table_sort_t)(char *, int);
+
+/*
+ * Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of
+ * the way to -256..-1, to avoid conflicting with real section
+ * indices.
+ */
+#define SPECIAL(i) ((i) - (SHN_HIRESERVE + 1))
+
+static inline int is_shndx_special(unsigned int i)
+{
+ return i != SHN_XINDEX && i >= SHN_LORESERVE && i <= SHN_HIRESERVE;
+}
+
+/* Accessor for sym->st_shndx, hides ugliness of "64k sections" */
+static inline unsigned int get_secindex(unsigned int shndx,
+ unsigned int sym_offs,
+ const Elf32_Word *symtab_shndx_start)
+{
+ if (is_shndx_special(shndx))
+ return SPECIAL(shndx);
+ if (shndx != SHN_XINDEX)
+ return shndx;
+ return r(&symtab_shndx_start[sym_offs]);
+}
+
+/* 32 bit and 64 bit are very similar */
+#include "sortextable.h"
+#define SORTEXTABLE_64
+#include "sortextable.h"
+
+static int compare_relative_table(const void *a, const void *b)
+{
+ int32_t av = (int32_t)r(a);
+ int32_t bv = (int32_t)r(b);
+
+ if (av < bv)
+ return -1;
+ if (av > bv)
+ return 1;
+ return 0;
+}
+
+static void sort_relative_table(char *extab_image, int image_size)
+{
+ int i;
+
+ /*
+ * Do the same thing the runtime sort does, first normalize to
+ * being relative to the start of the section.
+ */
+ i = 0;
+ while (i < image_size) {
+ uint32_t *loc = (uint32_t *)(extab_image + i);
+ w(r(loc) + i, loc);
+ i += 4;
+ }
+
+ qsort(extab_image, image_size / 8, 8, compare_relative_table);
+
+ /* Now denormalize. */
+ i = 0;
+ while (i < image_size) {
+ uint32_t *loc = (uint32_t *)(extab_image + i);
+ w(r(loc) - i, loc);
+ i += 4;
+ }
+}
+
+static void
+do_file(char const *const fname)
+{
+ table_sort_t custom_sort;
+ Elf32_Ehdr *ehdr = mmap_file(fname);
+
+ ehdr_curr = ehdr;
+ switch (ehdr->e_ident[EI_DATA]) {
+ default:
+ fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
+ ehdr->e_ident[EI_DATA], fname);
+ fail_file();
+ break;
+ case ELFDATA2LSB:
+ r = rle;
+ r2 = r2le;
+ r8 = r8le;
+ w = wle;
+ w2 = w2le;
+ w8 = w8le;
+ break;
+ case ELFDATA2MSB:
+ r = rbe;
+ r2 = r2be;
+ r8 = r8be;
+ w = wbe;
+ w2 = w2be;
+ w8 = w8be;
+ break;
+ } /* end switch */
+ if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0
+ || r2(&ehdr->e_type) != ET_EXEC
+ || ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
+ fprintf(stderr, "unrecognized ET_EXEC file %s\n", fname);
+ fail_file();
+ }
+
+ custom_sort = NULL;
+ switch (r2(&ehdr->e_machine)) {
+ default:
+ fprintf(stderr, "unrecognized e_machine %d %s\n",
+ r2(&ehdr->e_machine), fname);
+ fail_file();
+ break;
+ case EM_386:
+ case EM_X86_64:
+ case EM_S390:
+ custom_sort = sort_relative_table;
+ break;
+ case EM_ARCOMPACT:
+ case EM_ARM:
+ case EM_AARCH64:
+ case EM_MICROBLAZE:
+ case EM_MIPS:
+ case EM_XTENSA:
+ break;
+ } /* end switch */
+
+ switch (ehdr->e_ident[EI_CLASS]) {
+ default:
+ fprintf(stderr, "unrecognized ELF class %d %s\n",
+ ehdr->e_ident[EI_CLASS], fname);
+ fail_file();
+ break;
+ case ELFCLASS32:
+ if (r2(&ehdr->e_ehsize) != sizeof(Elf32_Ehdr)
+ || r2(&ehdr->e_shentsize) != sizeof(Elf32_Shdr)) {
+ fprintf(stderr,
+ "unrecognized ET_EXEC file: %s\n", fname);
+ fail_file();
+ }
+ do32(ehdr, fname, custom_sort);
+ break;
+ case ELFCLASS64: {
+ Elf64_Ehdr *const ghdr = (Elf64_Ehdr *)ehdr;
+ if (r2(&ghdr->e_ehsize) != sizeof(Elf64_Ehdr)
+ || r2(&ghdr->e_shentsize) != sizeof(Elf64_Shdr)) {
+ fprintf(stderr,
+ "unrecognized ET_EXEC file: %s\n", fname);
+ fail_file();
+ }
+ do64(ghdr, fname, custom_sort);
+ break;
+ }
+ } /* end switch */
+
+ cleanup();
+}
+
+int
+main(int argc, char *argv[])
+{
+ int n_error = 0; /* gcc-4.3.0 false positive complaint */
+ int i;
+
+ if (argc < 2) {
+ fprintf(stderr, "usage: sortextable vmlinux...\n");
+ return 0;
+ }
+
+ /* Process each file in turn, allowing deep failure. */
+ for (i = 1; i < argc; i++) {
+ char *file = argv[i];
+ int const sjval = setjmp(jmpenv);
+
+ switch (sjval) {
+ default:
+ fprintf(stderr, "internal error: %s\n", file);
+ exit(1);
+ break;
+ case SJ_SETJMP: /* normal sequence */
+ /* Avoid problems if early cleanup() */
+ fd_map = -1;
+ ehdr_curr = NULL;
+ mmap_failed = 1;
+ do_file(file);
+ break;
+ case SJ_FAIL: /* error in do_file or below */
+ ++n_error;
+ break;
+ case SJ_SUCCEED: /* premature success */
+ /* do nothing */
+ break;
+ } /* end switch */
+ }
+ return !!n_error;
+}
Code Review / kvmfornfv.git / blobdiff