Commit 57cafdf2 authored by Shile Zhang's avatar Shile Zhang Committed by Ingo Molnar
Browse files

scripts/sortextable: Refactor the do_func() function 



Refine the loop, naming and code structure, make the code more readable
and extendable. No functional changes intended.

Signed-off-by: default avatarShile Zhang <shile.zhang@linux.alibaba.com>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: linux-kbuild@vger.kernel.org
Link: https://lkml.kernel.org/r/20191204004633.88660-5-shile.zhang@linux.alibaba.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent abe4f92c

scripts/sortextable.c

+2 −2
Original line number Diff line number Diff line
@@ -320,7 +320,7 @@ static int do_file(char const *const fname, void *addr) 
				"unrecognized ET_EXEC/ET_DYN file: %s\n", fname);

			break;

		}

		rc = do32(ehdr, fname, custom_sort);

		rc = do_sort_32(ehdr, fname, custom_sort);

		break;

	case ELFCLASS64:

		{
@@ -332,7 +332,7 @@ static int do_file(char const *const fname, void *addr) 
				fname);

			break;

		}

		rc = do64(ghdr, fname, custom_sort);

		rc = do_sort_64(ghdr, fname, custom_sort);

		}

		break;

	default:

scripts/sortextable.h

+59 −56
Original line number Diff line number Diff line
@@ -12,7 +12,7 @@ 


#undef extable_ent_size

#undef compare_extable

#undef do_func

#undef do_sort

#undef Elf_Addr

#undef Elf_Ehdr

#undef Elf_Shdr
@@ -34,7 +34,7 @@ 
#ifdef SORTEXTABLE_64

# define extable_ent_size	16

# define compare_extable	compare_extable_64

# define do_func		do64

# define do_sort		do_sort_64

# define Elf_Addr		Elf64_Addr

# define Elf_Ehdr		Elf64_Ehdr

# define Elf_Shdr		Elf64_Shdr
@@ -55,7 +55,7 @@ 
#else

# define extable_ent_size	8

# define compare_extable	compare_extable_32

# define do_func		do32

# define do_sort		do_sort_32

# define Elf_Addr		Elf32_Addr

# define Elf_Ehdr		Elf32_Ehdr

# define Elf_Shdr		Elf32_Shdr
@@ -87,81 +87,81 @@ static int compare_extable(const void *a, const void *b) 
	return 0;

}



static int do_func(Elf_Ehdr *ehdr,

static int do_sort(Elf_Ehdr *ehdr,

		   char const *const fname,

		   table_sort_t custom_sort)

{

	Elf_Shdr *shdr;

	Elf_Shdr *shstrtab_sec;

	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_start = NULL;

	Elf_Sym *sort_needed_sym;

	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_done_location;

	const char *secstrtab;

	uint32_t *sort_needed_loc;

	const char *secstrings;

	const char *strtab;

	char *extab_image;

	int extab_index = 0;

	int i;

	int idx;

	unsigned int num_sections;

	unsigned int secindex_strings;

	unsigned int shnum;

	unsigned int shstrndx;



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

	shstrndx = r2(&ehdr->e_shstrndx);

	if (shstrndx == SHN_XINDEX)

		shstrndx = r(&shdr[0].sh_link);

	secstrings = (const char *)ehdr + _r(&shdr[shstrndx].sh_offset);



	num_sections = r2(&ehdr->e_shnum);

	if (num_sections == SHN_UNDEF)

		num_sections = _r(&shdr[0].sh_size);

	shnum = r2(&ehdr->e_shnum);

	if (shnum == SHN_UNDEF)

		shnum = _r(&shdr[0].sh_size);



	secindex_strings = r2(&ehdr->e_shstrndx);

	if (secindex_strings == SHN_XINDEX)

		secindex_strings = r(&shdr[0].sh_link);



	shstrtab_sec = shdr + secindex_strings;

	secstrtab = (const char *)ehdr + _r(&shstrtab_sec->sh_offset);

	for (i = 0; i < num_sections; i++) {

		idx = r(&shdr[i].sh_name);

		if (!strcmp(secstrtab + idx, "__ex_table")) {

			extab_sec = shdr + i;

	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 ((r(&shdr[i].sh_type) == SHT_REL ||

		     r(&shdr[i].sh_type) == SHT_RELA) &&

		    r(&shdr[i].sh_info) == extab_index) {

			relocs = (void *)ehdr + _r(&shdr[i].sh_offset);

			relocs_size = _r(&shdr[i].sh_size);

		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 (!strcmp(secstrtab + idx, ".symtab"))

			symtab_sec = shdr + i;

		if (!strcmp(secstrtab + idx, ".strtab"))

			strtab_sec = shdr + i;

		if (r(&shdr[i].sh_type) == SHT_SYMTAB_SHNDX)

			symtab_shndx_start = (Elf32_Word *)(

				(const char *)ehdr + _r(&shdr[i].sh_offset));

		if (r(&s->sh_type) == SHT_SYMTAB_SHNDX)

			symtab_shndx = (Elf32_Word *)((const char *)ehdr +

						      _r(&s->sh_offset));

	}

	if (!strtab_sec) {

		fprintf(stderr,	"no .strtab in file: %s\n", fname);



	if (!extab_sec) {

		fprintf(stderr,	"no __ex_table in file: %s\n", fname);

		return -1;

	}



	if (!symtab_sec) {

		fprintf(stderr,	"no .symtab in file: %s\n", fname);

		return -1;

	}

	symtab = (const Elf_Sym *)((const char *)ehdr +

				   _r(&symtab_sec->sh_offset));

	if (!extab_sec) {

		fprintf(stderr,	"no __ex_table in file: %s\n", fname);



	if (!strtab_sec) {

		fprintf(stderr,	"no .strtab in file: %s\n", fname);

		return -1;

	}

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



	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));
@@ -170,38 +170,41 @@ static int do_func(Elf_Ehdr *ehdr, 
		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 main_extable_sort_needed */

	sort_needed_sym = NULL;

	for (i = 0; i < _r(&symtab_sec->sh_size) / sizeof(Elf_Sym); i++) {

		sym = (void *)ehdr + _r(&symtab_sec->sh_offset);

		sym += i;

	/* 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;

		idx = r(&sym->st_name);

		if (!strcmp(strtab + idx, "main_extable_sort_needed")) {

		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\n",

			fname);

		return -1;

	}



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

					     sort_needed_sym - symtab,

					     symtab_shndx_start)];

	sort_done_location = (void *)ehdr +

					     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);



	/* We sorted it, clear the flag. */

	w(0, sort_done_location);

	/* extable has been sorted, clear the flag */

	w(0, sort_needed_loc);



	return 0;

}

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