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/* Code for loading Linux executables. Mostly linux kenrel 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. */
void memcpy_to_target(target_ulong dest, const void *src,
unsigned long len)
{
void *host_ptr;
host_ptr = lock_user(dest, len, 0);
memcpy(host_ptr, src, len);
unlock_user(host_ptr, dest, 1);
}
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;
}
}
memset(bprm->buf, 0, sizeof(bprm->buf));
retval = lseek(bprm->fd, 0L, SEEK_SET);
if(retval >= 0) {
retval = read(bprm->fd, bprm->buf, 128);
}
if(retval < 0) {
perror("prepare_binprm");
exit(-1);
/* return(-errno); */
}
else {
return(retval);
}
}
/* Construct the envp and argv tables on the target stack. */
target_ulong loader_build_argptr(int envc, int argc, target_ulong sp,
target_ulong stringp, int push_ptr)
{
int n = sizeof(target_ulong);
target_ulong envp;
target_ulong argv;
sp -= (envc + 1) * n;
envp = sp;
sp -= (argc + 1) * n;
argv = sp;
if (push_ptr) {
sp -= n; tputl(sp, envp);
sp -= n; tputl(sp, argv);
}
sp -= n; tputl(sp, argc);
while (argc-- > 0) {
tputl(argv, stringp); argv += n;
stringp += target_strlen(stringp) + 1;
}
tputl(argv, 0);
while (envc-- > 0) {
tputl(envp, stringp); envp += n;
stringp += target_strlen(stringp) + 1;
}
tputl(envp, 0);
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);
for (i=0 ; i<MAX_ARG_PAGES ; i++) /* clear page-table */
bprm.page[i] = 0;
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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