// SPDX-License-Identifier: GPL-2.0-only

  /*

   * sorttable.c: Sort the kernel's table

   *

   * Added ORC unwind tables sort support and other updates:
   * Copyright (C) 1999-2019 Alibaba Group Holding Limited. by:
   * Shile Zhang <shile.zhang@linux.alibaba.com>
   *

   * 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.

   *
   * 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 <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

  #ifndef EM_ARCV2
  #define EM_ARCV2	195
  #endif

  static uint32_t (*r)(const uint32_t *);
  static uint16_t (*r2)(const uint16_t *);
  static uint64_t (*r8)(const uint64_t *);
  static void (*w)(uint32_t, uint32_t *);
  static void (*w2)(uint16_t, uint16_t *);
  static void (*w8)(uint64_t, uint64_t *);
  typedef void (*table_sort_t)(char *, int);

  /*
   * 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, size_t *size)

  {

  	int fd;
  	struct stat sb;
  	void *addr = NULL;

  	fd = open(fname, O_RDWR);
  	if (fd < 0) {

  		perror(fname);

  		return NULL;
  	}
  	if (fstat(fd, &sb) < 0) {
  		perror(fname);
  		goto out;

  	}
  	if (!S_ISREG(sb.st_mode)) {
  		fprintf(stderr, "not a regular file: %s
  ", fname);

  		goto out;

  	}

  	addr = mmap(0, sb.st_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);

  	if (addr == MAP_FAILED) {

  		fprintf(stderr, "Could not mmap file: %s
  ", fname);

  		goto out;

  	}

  
  	*size = sb.st_size;
  
  out:
  	close(fd);

  	return addr;
  }

  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 r8be(const uint64_t *x)

  {

  	return get_unaligned_be64(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 uint64_t r8le(const uint64_t *x)

  {

  	return get_unaligned_le64(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 w8be(uint64_t val, uint64_t *x)

  {

  	put_unaligned_be64(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 void w8le(uint64_t val, uint64_t *x)
  {
  	put_unaligned_le64(val, x);
  }

  /*
   * 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 "sorttable.h"
  #define SORTTABLE_64
  #include "sorttable.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 = 0;

  	/*
  	 * Do the same thing the runtime sort does, first normalize to
  	 * being relative to the start of the section.
  	 */

  	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 x86_sort_relative_table(char *extab_image, int image_size)

  {

  	int i = 0;

  	while (i < image_size) {
  		uint32_t *loc = (uint32_t *)(extab_image + i);

  		w(r(loc) + i, loc);

  		w(r(loc + 1) + i + 4, loc + 1);
  		w(r(loc + 2) + i + 8, loc + 2);
  
  		i += sizeof(uint32_t) * 3;

  	}

  	qsort(extab_image, image_size / 12, 12, compare_relative_table);

  	i = 0;
  	while (i < image_size) {
  		uint32_t *loc = (uint32_t *)(extab_image + i);

  		w(r(loc) - i, loc);

  		w(r(loc + 1) - (i + 4), loc + 1);
  		w(r(loc + 2) - (i + 8), loc + 2);
  
  		i += sizeof(uint32_t) * 3;

  	}
  }

  static void s390_sort_relative_table(char *extab_image, int image_size)
  {
  	int i;
  
  	for (i = 0; i < image_size; i += 16) {
  		char *loc = extab_image + i;
  		uint64_t handler;
  
  		w(r((uint32_t *)loc) + i, (uint32_t *)loc);
  		w(r((uint32_t *)(loc + 4)) + (i + 4), (uint32_t *)(loc + 4));
  		/*
  		 * 0 is a special self-relative handler value, which means that
  		 * handler should be ignored. It is safe, because it means that
  		 * handler field points to itself, which should never happen.
  		 * When creating extable-relative values, keep it as 0, since
  		 * this should never occur either: it would mean that handler
  		 * field points to the first extable entry.
  		 */
  		handler = r8((uint64_t *)(loc + 8));
  		if (handler)
  			handler += i + 8;
  		w8(handler, (uint64_t *)(loc + 8));
  	}
  
  	qsort(extab_image, image_size / 16, 16, compare_relative_table);
  
  	for (i = 0; i < image_size; i += 16) {
  		char *loc = extab_image + i;
  		uint64_t handler;
  
  		w(r((uint32_t *)loc) - i, (uint32_t *)loc);
  		w(r((uint32_t *)(loc + 4)) - (i + 4), (uint32_t *)(loc + 4));
  		handler = r8((uint64_t *)(loc + 8));
  		if (handler)
  			handler -= i + 8;
  		w8(handler, (uint64_t *)(loc + 8));
  	}
  }

  static int do_file(char const *const fname, void *addr)

  {

  	int rc = -1;

  	Elf32_Ehdr *ehdr = addr;
  	table_sort_t custom_sort = NULL;

  	switch (ehdr->e_ident[EI_DATA]) {

  	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;

  	default:
  		fprintf(stderr, "unrecognized ELF data encoding %d: %s
  ",
  			ehdr->e_ident[EI_DATA], fname);
  		return -1;
  	}
  
  	if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0 ||
  	    (r2(&ehdr->e_type) != ET_EXEC && r2(&ehdr->e_type) != ET_DYN) ||
  	    ehdr->e_ident[EI_VERSION] != EV_CURRENT) {

  		fprintf(stderr, "unrecognized ET_EXEC/ET_DYN file %s
  ", fname);

  		return -1;

  	}

  	switch (r2(&ehdr->e_machine)) {

  	case EM_386:

  	case EM_X86_64:

  		custom_sort = x86_sort_relative_table;
  		break;

  	case EM_S390:

  		custom_sort = s390_sort_relative_table;
  		break;

  	case EM_AARCH64:

  	case EM_PARISC:

  	case EM_PPC:
  	case EM_PPC64:

  		custom_sort = sort_relative_table;
  		break;

  	case EM_ARCOMPACT:

  	case EM_ARCV2:

  	case EM_ARM:

  	case EM_MICROBLAZE:

  	case EM_MIPS:

  	case EM_XTENSA:

  		break;

  	default:
  		fprintf(stderr, "unrecognized e_machine %d %s
  ",
  			r2(&ehdr->e_machine), fname);
  		return -1;
  	}

  
  	switch (ehdr->e_ident[EI_CLASS]) {

  	case ELFCLASS32:

  		if (r2(&ehdr->e_ehsize) != sizeof(Elf32_Ehdr) ||
  		    r2(&ehdr->e_shentsize) != sizeof(Elf32_Shdr)) {

  			fprintf(stderr,

  				"unrecognized ET_EXEC/ET_DYN file: %s
  ", fname);

  			break;

  		}

  		rc = do_sort_32(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/ET_DYN file: %s
  ",
  				fname);

  			break;

  		}

  		rc = do_sort_64(ghdr, fname, custom_sort);

  		}
  		break;
  	default:
  		fprintf(stderr, "unrecognized ELF class %d %s
  ",
  			ehdr->e_ident[EI_CLASS], fname);

  		break;
  	}

  	return rc;

  }

  int main(int argc, char *argv[])

  {

  	int i, n_error = 0;  /* gcc-4.3.0 false positive complaint */
  	size_t size = 0;
  	void *addr = NULL;

  
  	if (argc < 2) {

  		fprintf(stderr, "usage: sorttable vmlinux...
  ");

  		return 0;
  	}
  
  	/* Process each file in turn, allowing deep failure. */
  	for (i = 1; i < argc; i++) {

  		addr = mmap_file(argv[i], &size);
  		if (!addr) {
  			++n_error;
  			continue;
  		}

  		if (do_file(argv[i], addr))

  			++n_error;

  
  		munmap(addr, size);

  	}

  	return !!n_error;
  }