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x86/vdso, build: Fix cross-compilation from big-endian architectures

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This adds a macro GET(x) to convert x from big-endian to
little-endian.  Hopefully I put it everywhere it needs to go and got
all the cases needed for everyone's linux/elf.h.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/2cf258df123cb24bad63c274c8563c050547d99d.1401464755.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This commit is contained in:
Andy Lutomirski 2014-05-30 08:48:49 -07:00 committed by H. Peter Anvin
parent 011561837d
commit add4eed0a2
2 changed files with 50 additions and 28 deletions
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15
arch/x86/vdso/vdso2c.c
View File

@ -51,6 +51,21 @@ static void fail(const char *format, ...)
va_end(ap);
}
/*
* Evil macros to do a little-endian read.
*/
#define __GET_TYPE(x, type, bits, ifnot) \
__builtin_choose_expr( \
__builtin_types_compatible_p(typeof(x), type), \
le##bits##toh((x)), ifnot)
extern void bad_get(uint64_t);
#define GET(x) \
__GET_TYPE((x), __u32, 32, __GET_TYPE((x), __u64, 64, \
__GET_TYPE((x), __s32, 32, __GET_TYPE((x), __s64, 64, \
__GET_TYPE((x), __u16, 16, bad_get(x))))))
#define NSYMS (sizeof(required_syms) / sizeof(required_syms[0]))
#define BITS 64

63
arch/x86/vdso/vdso2c.h
View File

@ -18,25 +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 + hdr->e_phoff);
Elf_Phdr *pt = (Elf_Phdr *)(addr + GET(hdr->e_phoff));
/* Walk the segment table. */
for (i = 0; i < hdr->e_phnum; i++) {
if (pt[i].p_type == PT_LOAD) {
for (i = 0; i < GET(hdr->e_phnum); i++) {
if (GET(pt[i].p_type) == PT_LOAD) {
if (found_load)
fail("multiple PT_LOAD segs\n");
if (pt[i].p_offset != 0 || pt[i].p_vaddr != 0)
if (GET(pt[i].p_offset) != 0 ||
GET(pt[i].p_vaddr) != 0)
fail("PT_LOAD in wrong place\n");
if (pt[i].p_memsz != pt[i].p_filesz)
if (GET(pt[i].p_memsz) != GET(pt[i].p_filesz))
fail("cannot handle memsz != filesz\n");
load_size = pt[i].p_memsz;
load_size = GET(pt[i].p_memsz);
found_load = 1;
} else if (pt[i].p_type == PT_DYNAMIC) {
dyn = addr + pt[i].p_offset;
dyn_end = addr + pt[i].p_offset + pt[i].p_memsz;
} else if (GET(pt[i].p_type) == PT_DYNAMIC) {
dyn = addr + GET(pt[i].p_offset);
dyn_end = addr + GET(pt[i].p_offset) +
GET(pt[i].p_memsz);
}
}
if (!found_load)
@ -44,43 +46,48 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
data_size = (load_size + 4095) / 4096 * 4096;
/* Walk the dynamic table */
for (i = 0; dyn + i < dyn_end && dyn[i].d_tag != DT_NULL; i++) {
if (dyn[i].d_tag == DT_REL || dyn[i].d_tag == DT_RELSZ ||
dyn[i].d_tag == DT_RELENT || dyn[i].d_tag == DT_TEXTREL)
for (i = 0; dyn + i < dyn_end && GET(dyn[i].d_tag) != DT_NULL; i++) {
typeof(dyn[i].d_tag) tag = GET(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 + hdr->e_shoff + hdr->e_shentsize*hdr->e_shstrndx;
secstrings = addr + secstrings_hdr->sh_offset;
for (i = 0; i < hdr->e_shnum; i++) {
Elf_Shdr *sh = addr + hdr->e_shoff + hdr->e_shentsize * i;
if (sh->sh_type == SHT_SYMTAB)
secstrings_hdr = addr + GET(hdr->e_shoff) +
GET(hdr->e_shentsize)*GET(hdr->e_shstrndx);
secstrings = addr + GET(secstrings_hdr->sh_offset);
for (i = 0; i < GET(hdr->e_shnum); i++) {
Elf_Shdr *sh = addr + GET(hdr->e_shoff) +
GET(hdr->e_shentsize) * i;
if (GET(sh->sh_type) == SHT_SYMTAB)
symtab_hdr = sh;
if (!strcmp(secstrings + sh->sh_name, ".altinstructions"))
if (!strcmp(secstrings + GET(sh->sh_name), ".altinstructions"))
alt_sec = sh;
}
if (!symtab_hdr)
fail("no symbol table\n");
strtab_hdr = addr + hdr->e_shoff +
hdr->e_shentsize * symtab_hdr->sh_link;
strtab_hdr = addr + GET(hdr->e_shoff) +
GET(hdr->e_shentsize) * GET(symtab_hdr->sh_link);
/* Walk the symbol table */
for (i = 0; i < symtab_hdr->sh_size / symtab_hdr->sh_entsize; i++) {
for (i = 0; i < GET(symtab_hdr->sh_size) / GET(symtab_hdr->sh_entsize);
i++) {
int k;
Elf_Sym *sym = addr + symtab_hdr->sh_offset +
symtab_hdr->sh_entsize * i;
const char *name = addr + strtab_hdr->sh_offset + sym->st_name;
Elf_Sym *sym = addr + GET(symtab_hdr->sh_offset) +
GET(symtab_hdr->sh_entsize) * i;
const char *name = addr + GET(strtab_hdr->sh_offset) +
GET(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] = sym->st_value;
syms[k] = GET(sym->st_value);
}
}
}
@ -106,7 +113,7 @@ static void GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
hdr->e_shoff = 0;
hdr->e_shentsize = 0;
hdr->e_shnum = 0;
hdr->e_shstrndx = SHN_UNDEF;
hdr->e_shstrndx = htole16(SHN_UNDEF);
if (!name) {
fwrite(addr, load_size, 1, outfile);
@ -140,9 +147,9 @@ 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)alt_sec->sh_offset);
(unsigned long)GET(alt_sec->sh_offset));
fprintf(outfile, "\t.alt_len = %lu,\n",
(unsigned long)alt_sec->sh_size);
(unsigned long)GET(alt_sec->sh_size));
}
for (i = 0; i < NSYMS; i++) {
if (syms[i])