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/* Code for loading Linux executables. Mostly linux kernel code. */
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include "qemu.h"
#define NGROUPS 32
/* ??? This should really be somewhere else. */
abi_long memcpy_to_target(abi_ulong dest, const void *src,
unsigned long len)
{
void *host_ptr;
host_ptr = lock_user(VERIFY_WRITE, dest, len, 0);
if (!host_ptr)
return -TARGET_EFAULT;
memcpy(host_ptr, src, len);
unlock_user(host_ptr, dest, 1);
return 0;
}
static int in_group_p(gid_t g)
{
/* return TRUE if we're in the specified group, FALSE otherwise */
int ngroup;
int i;
gid_t grouplist[NGROUPS];
ngroup = getgroups(NGROUPS, grouplist);
for(i = 0; i < ngroup; i++) {
if(grouplist[i] == g) {
return 1;
}
}
return 0;
}
static int count(char ** vec)
{
int i;
for(i = 0; *vec; i++) {
vec++;
}
return(i);
}
static int prepare_binprm(struct linux_binprm *bprm)
{
struct stat st;
int mode;
int retval, id_change;
if(fstat(bprm->fd, &st) < 0) {
return(-errno);
}
mode = st.st_mode;
if(!S_ISREG(mode)) { /* Must be regular file */
return(-EACCES);
}
if(!(mode & 0111)) { /* Must have at least one execute bit set */
return(-EACCES);
}
bprm->e_uid = geteuid();
bprm->e_gid = getegid();
id_change = 0;
/* Set-uid? */
if(mode & S_ISUID) {
bprm->e_uid = st.st_uid;
if(bprm->e_uid != geteuid()) {
id_change = 1;
}
}
/* Set-gid? */
/*
* If setgid is set but no group execute bit then this
* is a candidate for mandatory locking, not a setgid
* executable.
*/
if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
bprm->e_gid = st.st_gid;
if (!in_group_p(bprm->e_gid)) {
id_change = 1;
}
}
retval = read(bprm->fd, bprm->buf, BPRM_BUF_SIZE);
if (retval < 0) {
perror("prepare_binprm");
exit(-1);
}
if (retval < BPRM_BUF_SIZE) {
/* Make sure the rest of the loader won't read garbage. */
memset(bprm->buf + retval, 0, BPRM_BUF_SIZE - retval);
}
return retval;
}
/* Construct the envp and argv tables on the target stack. */
abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
abi_ulong stringp, int push_ptr)
{
TaskState *ts = (TaskState *)thread_env->opaque;
int n = sizeof(abi_ulong);
abi_ulong envp;
abi_ulong argv;
sp -= (envc + 1) * n;
envp = sp;
sp -= (argc + 1) * n;
argv = sp;
if (push_ptr) {
/* FIXME - handle put_user() failures */
sp -= n;
put_user_ual(envp, sp);
sp -= n;
put_user_ual(argv, sp);
}
sp -= n;
/* FIXME - handle put_user() failures */
put_user_ual(argc, sp);
ts->info->arg_start = stringp;
while (argc-- > 0) {
/* FIXME - handle put_user() failures */
put_user_ual(stringp, argv);
argv += n;
stringp += target_strlen(stringp) + 1;
}
ts->info->arg_end = stringp;
/* FIXME - handle put_user() failures */
put_user_ual(0, argv);
while (envc-- > 0) {
/* FIXME - handle put_user() failures */
put_user_ual(stringp, envp);
envp += n;
stringp += target_strlen(stringp) + 1;
}
/* FIXME - handle put_user() failures */
put_user_ual(0, envp);
return sp;
}
int loader_exec(const char * filename, char ** argv, char ** envp,
struct target_pt_regs * regs, struct image_info *infop,
struct linux_binprm *bprm)
{
int retval;
int i;
bprm->p = TARGET_PAGE_SIZE*MAX_ARG_PAGES-sizeof(unsigned int);
memset(bprm->page, 0, sizeof(bprm->page));
retval = open(filename, O_RDONLY);
if (retval < 0)
return retval;
bprm->fd = retval;
bprm->filename = (char *)filename;
bprm->argc = count(argv);
bprm->argv = argv;
bprm->envc = count(envp);
bprm->envp = envp;
retval = prepare_binprm(bprm);
if(retval>=0) {
if (bprm->buf[0] == 0x7f
&& bprm->buf[1] == 'E'
&& bprm->buf[2] == 'L'
&& bprm->buf[3] == 'F') {
retval = load_elf_binary(bprm, regs, infop);
#if defined(TARGET_HAS_BFLT)
} else if (bprm->buf[0] == 'b'
&& bprm->buf[1] == 'F'
&& bprm->buf[2] == 'L'
&& bprm->buf[3] == 'T') {
retval = load_flt_binary(bprm,regs,infop);
#endif
} else {
fprintf(stderr, "Unknown binary format\n");
return -1;
}
}
if(retval>=0) {
/* success. Initialize important registers */
do_init_thread(regs, infop);
return retval;
}
/* Something went wrong, return the inode and free the argument pages*/
for (i=0 ; i<MAX_ARG_PAGES ; i++) {
free(bprm->page[i]);
}
return(retval);
}
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