1 /* Code for loading BSD executables. Mostly linux kernel code. */
2
3 #include "qemu/osdep.h"
4
5 #include "qemu.h"
6
7 #define TARGET_NGROUPS 32
8
9 /* ??? This should really be somewhere else. */
memcpy_to_target(abi_ulong dest,const void * src,unsigned long len)10 abi_long memcpy_to_target(abi_ulong dest, const void *src,
11 unsigned long len)
12 {
13 void *host_ptr;
14
15 host_ptr = lock_user(VERIFY_WRITE, dest, len, 0);
16 if (!host_ptr)
17 return -TARGET_EFAULT;
18 memcpy(host_ptr, src, len);
19 unlock_user(host_ptr, dest, 1);
20 return 0;
21 }
22
count(char ** vec)23 static int count(char ** vec)
24 {
25 int i;
26
27 for(i = 0; *vec; i++) {
28 vec++;
29 }
30
31 return(i);
32 }
33
prepare_binprm(struct linux_binprm * bprm)34 static int prepare_binprm(struct linux_binprm *bprm)
35 {
36 struct stat st;
37 int mode;
38 int retval;
39
40 if(fstat(bprm->fd, &st) < 0) {
41 return(-errno);
42 }
43
44 mode = st.st_mode;
45 if(!S_ISREG(mode)) { /* Must be regular file */
46 return(-EACCES);
47 }
48 if(!(mode & 0111)) { /* Must have at least one execute bit set */
49 return(-EACCES);
50 }
51
52 bprm->e_uid = geteuid();
53 bprm->e_gid = getegid();
54
55 /* Set-uid? */
56 if(mode & S_ISUID) {
57 bprm->e_uid = st.st_uid;
58 }
59
60 /* Set-gid? */
61 /*
62 * If setgid is set but no group execute bit then this
63 * is a candidate for mandatory locking, not a setgid
64 * executable.
65 */
66 if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
67 bprm->e_gid = st.st_gid;
68 }
69
70 memset(bprm->buf, 0, sizeof(bprm->buf));
71 retval = lseek(bprm->fd, 0L, SEEK_SET);
72 if(retval >= 0) {
73 retval = read(bprm->fd, bprm->buf, 128);
74 }
75 if(retval < 0) {
76 perror("prepare_binprm");
77 exit(-1);
78 /* return(-errno); */
79 }
80 else {
81 return(retval);
82 }
83 }
84
85 /* Construct the envp and argv tables on the target stack. */
loader_build_argptr(int envc,int argc,abi_ulong sp,abi_ulong stringp,int push_ptr)86 abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
87 abi_ulong stringp, int push_ptr)
88 {
89 int n = sizeof(abi_ulong);
90 abi_ulong envp;
91 abi_ulong argv;
92
93 sp -= (envc + 1) * n;
94 envp = sp;
95 sp -= (argc + 1) * n;
96 argv = sp;
97 if (push_ptr) {
98 /* FIXME - handle put_user() failures */
99 sp -= n;
100 put_user_ual(envp, sp);
101 sp -= n;
102 put_user_ual(argv, sp);
103 }
104 sp -= n;
105 /* FIXME - handle put_user() failures */
106 put_user_ual(argc, sp);
107
108 while (argc-- > 0) {
109 /* FIXME - handle put_user() failures */
110 put_user_ual(stringp, argv);
111 argv += n;
112 stringp += target_strlen(stringp) + 1;
113 }
114 /* FIXME - handle put_user() failures */
115 put_user_ual(0, argv);
116 while (envc-- > 0) {
117 /* FIXME - handle put_user() failures */
118 put_user_ual(stringp, envp);
119 envp += n;
120 stringp += target_strlen(stringp) + 1;
121 }
122 /* FIXME - handle put_user() failures */
123 put_user_ual(0, envp);
124
125 return sp;
126 }
127
loader_exec(const char * filename,char ** argv,char ** envp,struct target_pt_regs * regs,struct image_info * infop)128 int loader_exec(const char * filename, char ** argv, char ** envp,
129 struct target_pt_regs * regs, struct image_info *infop)
130 {
131 struct linux_binprm bprm;
132 int retval;
133 int i;
134
135 bprm.p = TARGET_PAGE_SIZE*MAX_ARG_PAGES-sizeof(unsigned int);
136 for (i=0 ; i<MAX_ARG_PAGES ; i++) /* clear page-table */
137 bprm.page[i] = NULL;
138 retval = open(filename, O_RDONLY);
139 if (retval < 0)
140 return retval;
141 bprm.fd = retval;
142 bprm.filename = (char *)filename;
143 bprm.argc = count(argv);
144 bprm.argv = argv;
145 bprm.envc = count(envp);
146 bprm.envp = envp;
147
148 retval = prepare_binprm(&bprm);
149
150 if(retval>=0) {
151 if (bprm.buf[0] == 0x7f
152 && bprm.buf[1] == 'E'
153 && bprm.buf[2] == 'L'
154 && bprm.buf[3] == 'F') {
155 retval = load_elf_binary(&bprm,regs,infop);
156 } else {
157 fprintf(stderr, "Unknown binary format\n");
158 return -1;
159 }
160 }
161
162 if(retval>=0) {
163 /* success. Initialize important registers */
164 do_init_thread(regs, infop);
165 return retval;
166 }
167
168 /* Something went wrong, return the inode and free the argument pages*/
169 for (i=0 ; i<MAX_ARG_PAGES ; i++) {
170 g_free(bprm.page[i]);
171 }
172 return(retval);
173 }
174