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Commit bdfb9bcc authored by H. Peter Anvin's avatar H. Peter Anvin
Browse files

x86, vdso: Use <tools/le_byteshift.h> for littleendian access 



There are no standard functions for littleendian data (unlike
bigendian data.)  Thus, use <tools/le_byteshift.h> to access
littleendian data members.  Those are fairly inefficient, but it
doesn't matter for this purpose (and can be optimized later.)  This
avoids portability problems.

Reported-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
Tested-by: default avatarAndy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/20140606140017.afb7f91142f66cb3dd13c186@linux-foundation.org
parent a0abcf2e

arch/x86/vdso/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -59,6 +59,7 @@ VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \ 
$(obj)/vdso64.so.dbg: $(src)/vdso.lds $(vobjs) FORCE

	$(call if_changed,vdso)



HOST_EXTRACFLAGS += -I$(srctree)/tools/include

hostprogs-y			+= vdso2c



quiet_cmd_vdso2c = VDSO2C  $@

arch/x86/vdso/vdso2c.c

+6 −4
Original line number Diff line number Diff line
@@ -11,6 +11,8 @@ 
#include <sys/mman.h>

#include <sys/types.h>



#include <tools/le_byteshift.h>



#include <linux/elf.h>

#include <linux/types.h>
@@ -56,12 +58,12 @@ static void fail(const char *format, ...) 
 */

#define GLE(x, bits, ifnot)						\

	__builtin_choose_expr(						\

		(sizeof(x) == bits/8),					\

		(__typeof__(x))le##bits##toh(x), ifnot)

		(sizeof(*(x)) == bits/8),				\

		(__typeof__(*(x)))get_unaligned_le##bits(x), ifnot)



extern void bad_get_le(uint64_t);

extern void bad_get_le(void);

#define LAST_LE(x)							\

	__builtin_choose_expr(sizeof(x) == 1, (x), bad_get_le(x))

	__builtin_choose_expr(sizeof(*(x)) == 1, *(x), bad_get_le())



#define GET_LE(x)							\

	GLE(x, 64, GLE(x, 32, GLE(x, 16, LAST_LE(x))))

arch/x86/vdso/vdso2c.h

+31 −31
Original line number Diff line number Diff line
@@ -18,27 +18,27 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name) 
	const char *secstrings;

	uint64_t syms[NSYMS] = {};



	Elf_Phdr *pt = (Elf_Phdr *)(addr + GET_LE(hdr->e_phoff));

	Elf_Phdr *pt = (Elf_Phdr *)(addr + GET_LE(&hdr->e_phoff));



	/* Walk the segment table. */

	for (i = 0; i < GET_LE(hdr->e_phnum); i++) {

		if (GET_LE(pt[i].p_type) == PT_LOAD) {

	for (i = 0; i < GET_LE(&hdr->e_phnum); i++) {

		if (GET_LE(&pt[i].p_type) == PT_LOAD) {

			if (found_load)

				fail("multiple PT_LOAD segs\n");



			if (GET_LE(pt[i].p_offset) != 0 ||

			    GET_LE(pt[i].p_vaddr) != 0)

			if (GET_LE(&pt[i].p_offset) != 0 ||

			    GET_LE(&pt[i].p_vaddr) != 0)

				fail("PT_LOAD in wrong place\n");



			if (GET_LE(pt[i].p_memsz) != GET_LE(pt[i].p_filesz))

			if (GET_LE(&pt[i].p_memsz) != GET_LE(&pt[i].p_filesz))

				fail("cannot handle memsz != filesz\n");



			load_size = GET_LE(pt[i].p_memsz);

			load_size = GET_LE(&pt[i].p_memsz);

			found_load = 1;

		} else if (GET_LE(pt[i].p_type) == PT_DYNAMIC) {

			dyn = addr + GET_LE(pt[i].p_offset);

			dyn_end = addr + GET_LE(pt[i].p_offset) +

				GET_LE(pt[i].p_memsz);

		} else if (GET_LE(&pt[i].p_type) == PT_DYNAMIC) {

			dyn = addr + GET_LE(&pt[i].p_offset);

			dyn_end = addr + GET_LE(&pt[i].p_offset) +

				GET_LE(&pt[i].p_memsz);

		}

	}

	if (!found_load)
@@ -47,24 +47,24 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name) 


	/* Walk the dynamic table */

	for (i = 0; dyn + i < dyn_end &&

		     GET_LE(dyn[i].d_tag) != DT_NULL; i++) {

		typeof(dyn[i].d_tag) tag = GET_LE(dyn[i].d_tag);

		     GET_LE(&dyn[i].d_tag) != DT_NULL; i++) {

		typeof(dyn[i].d_tag) tag = GET_LE(&dyn[i].d_tag);

		if (tag == DT_REL || tag == DT_RELSZ ||

		    tag == DT_RELENT || tag == DT_TEXTREL)

			fail("vdso image contains dynamic relocations\n");

	}



	/* Walk the section table */

	secstrings_hdr = addr + GET_LE(hdr->e_shoff) +

		GET_LE(hdr->e_shentsize)*GET_LE(hdr->e_shstrndx);

	secstrings = addr + GET_LE(secstrings_hdr->sh_offset);

	for (i = 0; i < GET_LE(hdr->e_shnum); i++) {

		Elf_Shdr *sh = addr + GET_LE(hdr->e_shoff) +

			GET_LE(hdr->e_shentsize) * i;

		if (GET_LE(sh->sh_type) == SHT_SYMTAB)

	secstrings_hdr = addr + GET_LE(&hdr->e_shoff) +

		GET_LE(&hdr->e_shentsize)*GET_LE(&hdr->e_shstrndx);

	secstrings = addr + GET_LE(&secstrings_hdr->sh_offset);

	for (i = 0; i < GET_LE(&hdr->e_shnum); i++) {

		Elf_Shdr *sh = addr + GET_LE(&hdr->e_shoff) +

			GET_LE(&hdr->e_shentsize) * i;

		if (GET_LE(&sh->sh_type) == SHT_SYMTAB)

			symtab_hdr = sh;



		if (!strcmp(secstrings + GET_LE(sh->sh_name),

		if (!strcmp(secstrings + GET_LE(&sh->sh_name),

			    ".altinstructions"))

			alt_sec = sh;

	}
@@ -72,25 +72,25 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name) 
	if (!symtab_hdr)

		fail("no symbol table\n");



	strtab_hdr = addr + GET_LE(hdr->e_shoff) +

		GET_LE(hdr->e_shentsize) * GET_LE(symtab_hdr->sh_link);

	strtab_hdr = addr + GET_LE(&hdr->e_shoff) +

		GET_LE(&hdr->e_shentsize) * GET_LE(&symtab_hdr->sh_link);



	/* Walk the symbol table */

	for (i = 0;

	     i < GET_LE(symtab_hdr->sh_size) / GET_LE(symtab_hdr->sh_entsize);

	     i < GET_LE(&symtab_hdr->sh_size) / GET_LE(&symtab_hdr->sh_entsize);

	     i++) {

		int k;

		Elf_Sym *sym = addr + GET_LE(symtab_hdr->sh_offset) +

			GET_LE(symtab_hdr->sh_entsize) * i;

		const char *name = addr + GET_LE(strtab_hdr->sh_offset) +

			GET_LE(sym->st_name);

		Elf_Sym *sym = addr + GET_LE(&symtab_hdr->sh_offset) +

			GET_LE(&symtab_hdr->sh_entsize) * i;

		const char *name = addr + GET_LE(&strtab_hdr->sh_offset) +

			GET_LE(&sym->st_name);

		for (k = 0; k < NSYMS; k++) {

			if (!strcmp(name, required_syms[k])) {

				if (syms[k]) {

					fail("duplicate symbol %s\n",

					     required_syms[k]);

				}

				syms[k] = GET_LE(sym->st_value);

				syms[k] = GET_LE(&sym->st_value);

			}

		}

	}
@@ -150,9 +150,9 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name) 
	fprintf(outfile, "\t},\n");

	if (alt_sec) {

		fprintf(outfile, "\t.alt = %lu,\n",

			(unsigned long)GET_LE(alt_sec->sh_offset));

			(unsigned long)GET_LE(&alt_sec->sh_offset));

		fprintf(outfile, "\t.alt_len = %lu,\n",

			(unsigned long)GET_LE(alt_sec->sh_size));

			(unsigned long)GET_LE(&alt_sec->sh_size));

	}

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

		if (syms[i])