1 /* Code for loading Linux executables. Mostly linux kernel code. */
2
3 #include "qemu/osdep.h"
4
5 #include "qemu.h"
6
7 #define 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 retval = read(bprm->fd, bprm->buf, BPRM_BUF_SIZE);
71 if (retval < 0) {
72 perror("prepare_binprm");
73 exit(-1);
74 }
75 if (retval < BPRM_BUF_SIZE) {
76 /* Make sure the rest of the loader won't read garbage. */
77 memset(bprm->buf + retval, 0, BPRM_BUF_SIZE - retval);
78 }
79 return retval;
80 }
81
82 /* 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)83 abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
84 abi_ulong stringp, int push_ptr)
85 {
86 TaskState *ts = (TaskState *)thread_cpu->opaque;
87 int n = sizeof(abi_ulong);
88 abi_ulong envp;
89 abi_ulong argv;
90
91 sp -= (envc + 1) * n;
92 envp = sp;
93 sp -= (argc + 1) * n;
94 argv = sp;
95 if (push_ptr) {
96 /* FIXME - handle put_user() failures */
97 sp -= n;
98 put_user_ual(envp, sp);
99 sp -= n;
100 put_user_ual(argv, sp);
101 }
102 sp -= n;
103 /* FIXME - handle put_user() failures */
104 put_user_ual(argc, sp);
105 ts->info->arg_start = stringp;
106 while (argc-- > 0) {
107 /* FIXME - handle put_user() failures */
108 put_user_ual(stringp, argv);
109 argv += n;
110 stringp += target_strlen(stringp) + 1;
111 }
112 ts->info->arg_end = stringp;
113 /* FIXME - handle put_user() failures */
114 put_user_ual(0, argv);
115 while (envc-- > 0) {
116 /* FIXME - handle put_user() failures */
117 put_user_ual(stringp, envp);
118 envp += n;
119 stringp += target_strlen(stringp) + 1;
120 }
121 /* FIXME - handle put_user() failures */
122 put_user_ual(0, envp);
123
124 return sp;
125 }
126
loader_exec(int fdexec,const char * filename,char ** argv,char ** envp,struct target_pt_regs * regs,struct image_info * infop,struct linux_binprm * bprm)127 int loader_exec(int fdexec, const char *filename, char **argv, char **envp,
128 struct target_pt_regs * regs, struct image_info *infop,
129 struct linux_binprm *bprm)
130 {
131 int retval;
132
133 bprm->fd = fdexec;
134 bprm->filename = (char *)filename;
135 bprm->argc = count(argv);
136 bprm->argv = argv;
137 bprm->envc = count(envp);
138 bprm->envp = envp;
139
140 retval = prepare_binprm(bprm);
141
142 if(retval>=0) {
143 if (bprm->buf[0] == 0x7f
144 && bprm->buf[1] == 'E'
145 && bprm->buf[2] == 'L'
146 && bprm->buf[3] == 'F') {
147 retval = load_elf_binary(bprm, infop);
148 #if defined(TARGET_HAS_BFLT)
149 } else if (bprm->buf[0] == 'b'
150 && bprm->buf[1] == 'F'
151 && bprm->buf[2] == 'L'
152 && bprm->buf[3] == 'T') {
153 retval = load_flt_binary(bprm, infop);
154 #endif
155 } else {
156 return -ENOEXEC;
157 }
158 }
159
160 if(retval>=0) {
161 /* success. Initialize important registers */
162 do_init_thread(regs, infop);
163 return retval;
164 }
165
166 return(retval);
167 }
168