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

  /*

   * sorttable.h

   *

   * 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.

   *

   * Some of code was taken out of arch/x86/kernel/unwind_orc.c, written by:
   * Copyright (C) 2017 Josh Poimboeuf <jpoimboe@redhat.com>
   *

   * Some of this code was taken out of recordmcount.h written by:
   *

   * Copyright 2009 John F. Reiser <jreiser@BitWagon.com>. All rights reserved.

   * Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.

   */
  
  #undef extable_ent_size
  #undef compare_extable

  #undef do_sort

  #undef Elf_Addr
  #undef Elf_Ehdr
  #undef Elf_Shdr
  #undef Elf_Rel
  #undef Elf_Rela
  #undef Elf_Sym
  #undef ELF_R_SYM
  #undef Elf_r_sym
  #undef ELF_R_INFO
  #undef Elf_r_info
  #undef ELF_ST_BIND
  #undef ELF_ST_TYPE
  #undef fn_ELF_R_SYM
  #undef fn_ELF_R_INFO
  #undef uint_t

  #undef _r

  #undef _w

  #ifdef SORTTABLE_64

  # define extable_ent_size	16
  # define compare_extable	compare_extable_64

  # define do_sort		do_sort_64

  # define Elf_Addr		Elf64_Addr
  # define Elf_Ehdr		Elf64_Ehdr
  # define Elf_Shdr		Elf64_Shdr
  # define Elf_Rel		Elf64_Rel
  # define Elf_Rela		Elf64_Rela
  # define Elf_Sym		Elf64_Sym
  # define ELF_R_SYM		ELF64_R_SYM
  # define Elf_r_sym		Elf64_r_sym
  # define ELF_R_INFO		ELF64_R_INFO
  # define Elf_r_info		Elf64_r_info
  # define ELF_ST_BIND		ELF64_ST_BIND
  # define ELF_ST_TYPE		ELF64_ST_TYPE
  # define fn_ELF_R_SYM		fn_ELF64_R_SYM
  # define fn_ELF_R_INFO		fn_ELF64_R_INFO
  # define uint_t			uint64_t

  # define _r			r8

  # define _w			w8
  #else
  # define extable_ent_size	8
  # define compare_extable	compare_extable_32

  # define do_sort		do_sort_32

  # define Elf_Addr		Elf32_Addr
  # define Elf_Ehdr		Elf32_Ehdr
  # define Elf_Shdr		Elf32_Shdr
  # define Elf_Rel		Elf32_Rel
  # define Elf_Rela		Elf32_Rela
  # define Elf_Sym		Elf32_Sym
  # define ELF_R_SYM		ELF32_R_SYM
  # define Elf_r_sym		Elf32_r_sym
  # define ELF_R_INFO		ELF32_R_INFO
  # define Elf_r_info		Elf32_r_info
  # define ELF_ST_BIND		ELF32_ST_BIND
  # define ELF_ST_TYPE		ELF32_ST_TYPE
  # define fn_ELF_R_SYM		fn_ELF32_R_SYM
  # define fn_ELF_R_INFO		fn_ELF32_R_INFO
  # define uint_t			uint32_t

  # define _r			r

  # define _w			w
  #endif

  #if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED)
  /* ORC unwinder only support X86_64 */
  #include <errno.h>
  #include <pthread.h>
  #include <asm/orc_types.h>
  
  #define ERRSTR_MAXSZ	256
  
  char g_err[ERRSTR_MAXSZ];
  int *g_orc_ip_table;
  struct orc_entry *g_orc_table;
  
  pthread_t orc_sort_thread;
  
  static inline unsigned long orc_ip(const int *ip)
  {
  	return (unsigned long)ip + *ip;
  }
  
  static int orc_sort_cmp(const void *_a, const void *_b)
  {
  	struct orc_entry *orc_a;
  	const int *a = g_orc_ip_table + *(int *)_a;
  	const int *b = g_orc_ip_table + *(int *)_b;
  	unsigned long a_val = orc_ip(a);
  	unsigned long b_val = orc_ip(b);
  
  	if (a_val > b_val)
  		return 1;
  	if (a_val < b_val)
  		return -1;
  
  	/*
  	 * The "weak" section terminator entries need to always be on the left
  	 * to ensure the lookup code skips them in favor of real entries.
  	 * These terminator entries exist to handle any gaps created by
  	 * whitelisted .o files which didn't get objtool generation.
  	 */
  	orc_a = g_orc_table + (a - g_orc_ip_table);
  	return orc_a->sp_reg == ORC_REG_UNDEFINED && !orc_a->end ? -1 : 1;
  }
  
  static void *sort_orctable(void *arg)
  {
  	int i;
  	int *idxs = NULL;
  	int *tmp_orc_ip_table = NULL;
  	struct orc_entry *tmp_orc_table = NULL;
  	unsigned int *orc_ip_size = (unsigned int *)arg;
  	unsigned int num_entries = *orc_ip_size / sizeof(int);
  	unsigned int orc_size = num_entries * sizeof(struct orc_entry);
  
  	idxs = (int *)malloc(*orc_ip_size);
  	if (!idxs) {
  		snprintf(g_err, ERRSTR_MAXSZ, "malloc idxs: %s",
  			 strerror(errno));
  		pthread_exit(g_err);
  	}
  
  	tmp_orc_ip_table = (int *)malloc(*orc_ip_size);
  	if (!tmp_orc_ip_table) {
  		snprintf(g_err, ERRSTR_MAXSZ, "malloc tmp_orc_ip_table: %s",
  			 strerror(errno));
  		pthread_exit(g_err);
  	}
  
  	tmp_orc_table = (struct orc_entry *)malloc(orc_size);
  	if (!tmp_orc_table) {
  		snprintf(g_err, ERRSTR_MAXSZ, "malloc tmp_orc_table: %s",
  			 strerror(errno));
  		pthread_exit(g_err);
  	}
  
  	/* initialize indices array, convert ip_table to absolute address */
  	for (i = 0; i < num_entries; i++) {
  		idxs[i] = i;
  		tmp_orc_ip_table[i] = g_orc_ip_table[i] + i * sizeof(int);
  	}
  	memcpy(tmp_orc_table, g_orc_table, orc_size);
  
  	qsort(idxs, num_entries, sizeof(int), orc_sort_cmp);
  
  	for (i = 0; i < num_entries; i++) {
  		if (idxs[i] == i)
  			continue;
  
  		/* convert back to relative address */
  		g_orc_ip_table[i] = tmp_orc_ip_table[idxs[i]] - i * sizeof(int);
  		g_orc_table[i] = tmp_orc_table[idxs[i]];
  	}
  
  	free(idxs);
  	free(tmp_orc_ip_table);
  	free(tmp_orc_table);
  	pthread_exit(NULL);
  }
  #endif

  static int compare_extable(const void *a, const void *b)
  {

  	Elf_Addr av = _r(a);
  	Elf_Addr bv = _r(b);

  	if (av < bv)

  		return -1;

  	if (av > bv)

  		return 1;
  	return 0;
  }

  static int do_sort(Elf_Ehdr *ehdr,

  		   char const *const fname,
  		   table_sort_t custom_sort)

  {

  	int rc = -1;

  	Elf_Shdr *s, *shdr = (Elf_Shdr *)((char *)ehdr + _r(&ehdr->e_shoff));

  	Elf_Shdr *strtab_sec = NULL;
  	Elf_Shdr *symtab_sec = NULL;
  	Elf_Shdr *extab_sec = NULL;
  	Elf_Sym *sym;

  	const Elf_Sym *symtab;

  	Elf32_Word *symtab_shndx = NULL;
  	Elf_Sym *sort_needed_sym = NULL;

  	Elf_Shdr *sort_needed_sec;

  	Elf_Rel *relocs = NULL;

  	int relocs_size = 0;

  	uint32_t *sort_needed_loc;
  	const char *secstrings;

  	const char *strtab;

  	char *extab_image;
  	int extab_index = 0;

  	int i;
  	int idx;

  	unsigned int shnum;
  	unsigned int shstrndx;

  #if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED)
  	unsigned int orc_ip_size = 0;
  	unsigned int orc_size = 0;
  	unsigned int orc_num_entries = 0;
  #endif

  	shstrndx = r2(&ehdr->e_shstrndx);
  	if (shstrndx == SHN_XINDEX)
  		shstrndx = r(&shdr[0].sh_link);
  	secstrings = (const char *)ehdr + _r(&shdr[shstrndx].sh_offset);

  	shnum = r2(&ehdr->e_shnum);
  	if (shnum == SHN_UNDEF)
  		shnum = _r(&shdr[0].sh_size);

  	for (i = 0, s = shdr; s < shdr + shnum; i++, s++) {
  		idx = r(&s->sh_name);
  		if (!strcmp(secstrings + idx, "__ex_table")) {
  			extab_sec = s;

  			extab_index = i;
  		}

  		if (!strcmp(secstrings + idx, ".symtab"))
  			symtab_sec = s;
  		if (!strcmp(secstrings + idx, ".strtab"))
  			strtab_sec = s;
  
  		if ((r(&s->sh_type) == SHT_REL ||
  		     r(&s->sh_type) == SHT_RELA) &&
  		    r(&s->sh_info) == extab_index) {
  			relocs = (void *)ehdr + _r(&s->sh_offset);
  			relocs_size = _r(&s->sh_size);

  		}

  		if (r(&s->sh_type) == SHT_SYMTAB_SHNDX)
  			symtab_shndx = (Elf32_Word *)((const char *)ehdr +
  						      _r(&s->sh_offset));

  
  #if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED)
  		/* locate the ORC unwind tables */
  		if (!strcmp(secstrings + idx, ".orc_unwind_ip")) {
  			orc_ip_size = s->sh_size;
  			g_orc_ip_table = (int *)((void *)ehdr +
  						   s->sh_offset);
  		}
  		if (!strcmp(secstrings + idx, ".orc_unwind")) {
  			orc_size = s->sh_size;
  			g_orc_table = (struct orc_entry *)((void *)ehdr +
  							     s->sh_offset);
  		}
  #endif
  	} /* for loop */
  
  #if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED)
  	if (!g_orc_ip_table || !g_orc_table) {
  		fprintf(stderr,
  			"incomplete ORC unwind tables in file: %s
  ", fname);
  		goto out;
  	}
  
  	orc_num_entries = orc_ip_size / sizeof(int);
  	if (orc_ip_size % sizeof(int) != 0 ||
  	    orc_size % sizeof(struct orc_entry) != 0 ||
  	    orc_num_entries != orc_size / sizeof(struct orc_entry)) {
  		fprintf(stderr,
  			"inconsistent ORC unwind table entries in file: %s
  ",
  			fname);
  		goto out;

  	}

  	/* create thread to sort ORC unwind tables concurrently */
  	if (pthread_create(&orc_sort_thread, NULL,
  			   sort_orctable, &orc_ip_size)) {
  		fprintf(stderr,
  			"pthread_create orc_sort_thread failed '%s': %s
  ",
  			strerror(errno), fname);
  		goto out;
  	}
  #endif

  	if (!extab_sec) {
  		fprintf(stderr,	"no __ex_table in file: %s
  ", fname);

  		goto out;

  	}

  	if (!symtab_sec) {
  		fprintf(stderr,	"no .symtab in file: %s
  ", fname);

  		goto out;

  	}

  
  	if (!strtab_sec) {
  		fprintf(stderr,	"no .strtab in file: %s
  ", fname);

  		goto out;

  	}

  	extab_image = (void *)ehdr + _r(&extab_sec->sh_offset);

  	strtab = (const char *)ehdr + _r(&strtab_sec->sh_offset);
  	symtab = (const Elf_Sym *)((const char *)ehdr +
  						  _r(&symtab_sec->sh_offset));

  
  	if (custom_sort) {
  		custom_sort(extab_image, _r(&extab_sec->sh_size));
  	} else {
  		int num_entries = _r(&extab_sec->sh_size) / extable_ent_size;
  		qsort(extab_image, num_entries,
  		      extable_ent_size, compare_extable);
  	}

  	/* If there were relocations, we no longer need them. */
  	if (relocs)
  		memset(relocs, 0, relocs_size);

  	/* find the flag main_extable_sort_needed */
  	for (sym = (void *)ehdr + _r(&symtab_sec->sh_offset);
  	     sym < sym + _r(&symtab_sec->sh_size) / sizeof(Elf_Sym);
  	     sym++) {

  		if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT)
  			continue;

  		if (!strcmp(strtab + r(&sym->st_name),
  			    "main_extable_sort_needed")) {

  			sort_needed_sym = sym;
  			break;
  		}
  	}

  	if (!sort_needed_sym) {

  		fprintf(stderr,

  			"no main_extable_sort_needed symbol in file: %s
  ",

  			fname);

  		goto out;

  	}

  	sort_needed_sec = &shdr[get_secindex(r2(&sym->st_shndx),
  					     sort_needed_sym - symtab,

  					     symtab_shndx)];
  	sort_needed_loc = (void *)ehdr +

  		_r(&sort_needed_sec->sh_offset) +
  		_r(&sort_needed_sym->st_value) -
  		_r(&sort_needed_sec->sh_addr);

  	/* extable has been sorted, clear the flag */
  	w(0, sort_needed_loc);

  	rc = 0;

  out:
  #if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED)
  	if (orc_sort_thread) {
  		void *retval = NULL;
  		/* wait for ORC tables sort done */
  		rc = pthread_join(orc_sort_thread, &retval);
  		if (rc)
  			fprintf(stderr,
  				"pthread_join failed '%s': %s
  ",
  				strerror(errno), fname);
  		else if (retval) {
  			rc = -1;
  			fprintf(stderr,
  				"failed to sort ORC tables '%s': %s
  ",
  				(char *)retval, fname);
  		}
  	}
  #endif
  	return rc;

  }