linux-user: introduce functions to detect CPU type

Add a function to return ELF e_flags and use it
to select the CPU model.

Signed-off-by: YunQiang Su <syq@debian.org>
[lv: split the patch and some cleanup in get_elf_eflags()]
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20180220173307.25125-3-laurent@vivier.eu>
This commit is contained in:
YunQiang Su 2018-02-20 18:33:05 +01:00 committed by Laurent Vivier
parent 542ca43498
commit 768fe76e92
3 changed files with 46 additions and 10 deletions

View file

@ -2396,6 +2396,41 @@ give_up:
g_free(syms);
}
uint32_t get_elf_eflags(int fd)
{
struct elfhdr ehdr;
off_t offset;
int ret;
/* Read ELF header */
offset = lseek(fd, 0, SEEK_SET);
if (offset == (off_t) -1) {
return 0;
}
ret = read(fd, &ehdr, sizeof(ehdr));
if (ret < sizeof(ehdr)) {
return 0;
}
offset = lseek(fd, offset, SEEK_SET);
if (offset == (off_t) -1) {
return 0;
}
/* Check ELF signature */
if (!elf_check_ident(&ehdr)) {
return 0;
}
/* check header */
bswap_ehdr(&ehdr);
if (!elf_check_ehdr(&ehdr)) {
return 0;
}
/* return architecture id */
return ehdr.e_flags;
}
int load_elf_binary(struct linux_binprm *bprm, struct image_info *info)
{
struct image_info interp_info;

View file

@ -4344,8 +4344,17 @@ int main(int argc, char **argv, char **envp)
init_qemu_uname_release();
execfd = qemu_getauxval(AT_EXECFD);
if (execfd == 0) {
execfd = open(filename, O_RDONLY);
if (execfd < 0) {
printf("Error while loading %s: %s\n", filename, strerror(errno));
_exit(EXIT_FAILURE);
}
}
if (cpu_model == NULL) {
cpu_model = cpu_get_model(0);
cpu_model = cpu_get_model(get_elf_eflags(execfd));
}
tcg_exec_init(0);
/* NOTE: we need to init the CPU at this stage to get
@ -4438,15 +4447,6 @@ int main(int argc, char **argv, char **envp)
cpu->opaque = ts;
task_settid(ts);
execfd = qemu_getauxval(AT_EXECFD);
if (execfd == 0) {
execfd = open(filename, O_RDONLY);
if (execfd < 0) {
printf("Error while loading %s: %s\n", filename, strerror(errno));
_exit(EXIT_FAILURE);
}
}
ret = loader_exec(execfd, filename, target_argv, target_environ, regs,
info, &bprm);
if (ret != 0) {

View file

@ -186,6 +186,7 @@ int loader_exec(int fdexec, const char *filename, char **argv, char **envp,
struct target_pt_regs * regs, struct image_info *infop,
struct linux_binprm *);
uint32_t get_elf_eflags(int fd);
int load_elf_binary(struct linux_binprm *bprm, struct image_info *info);
int load_flt_binary(struct linux_binprm *bprm, struct image_info *info);