xref: /openbmc/qemu/bsd-user/bsdload.c (revision 8f968b6a)
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.  */
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     }
19     memcpy(host_ptr, src, len);
20     unlock_user(host_ptr, dest, 1);
21     return 0;
22 }
23 
24 static int count(char **vec)
25 {
26     int         i;
27 
28     for (i = 0; *vec; i++) {
29         vec++;
30     }
31 
32     return i;
33 }
34 
35 static int prepare_binprm(struct bsd_binprm *bprm)
36 {
37     struct stat         st;
38     int mode;
39     int retval;
40 
41     if (fstat(bprm->fd, &st) < 0) {
42         return -errno;
43     }
44 
45     mode = st.st_mode;
46     if (!S_ISREG(mode)) {        /* Must be regular file */
47         return -EACCES;
48     }
49     if (!(mode & 0111)) {        /* Must have at least one execute bit set */
50         return -EACCES;
51     }
52 
53     bprm->e_uid = geteuid();
54     bprm->e_gid = getegid();
55 
56     /* Set-uid? */
57     if (mode & S_ISUID) {
58         bprm->e_uid = st.st_uid;
59     }
60 
61     /* Set-gid? */
62     /*
63      * If setgid is set but no group execute bit then this
64      * is a candidate for mandatory locking, not a setgid
65      * executable.
66      */
67     if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
68         bprm->e_gid = st.st_gid;
69     }
70 
71     memset(bprm->buf, 0, sizeof(bprm->buf));
72     retval = lseek(bprm->fd, 0L, SEEK_SET);
73     if (retval >= 0) {
74         retval = read(bprm->fd, bprm->buf, 128);
75     }
76     if (retval < 0) {
77         perror("prepare_binprm");
78         exit(-1);
79     } else {
80         return retval;
81     }
82 }
83 
84 /* Construct the envp and argv tables on the target stack.  */
85 abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp,
86                               abi_ulong stringp, int push_ptr)
87 {
88     int n = sizeof(abi_ulong);
89     abi_ulong envp;
90     abi_ulong argv;
91 
92     sp -= (envc + 1) * n;
93     envp = sp;
94     sp -= (argc + 1) * n;
95     argv = sp;
96     if (push_ptr) {
97         /* FIXME - handle put_user() failures */
98         sp -= n;
99         put_user_ual(envp, sp);
100         sp -= n;
101         put_user_ual(argv, sp);
102     }
103     sp -= n;
104     /* FIXME - handle put_user() failures */
105     put_user_ual(argc, sp);
106 
107     while (argc-- > 0) {
108         /* FIXME - handle put_user() failures */
109         put_user_ual(stringp, argv);
110         argv += n;
111         stringp += target_strlen(stringp) + 1;
112     }
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 
127 int loader_exec(const char *filename, char **argv, char **envp,
128              struct target_pt_regs *regs, struct image_info *infop)
129 {
130     struct bsd_binprm bprm;
131     int retval;
132     int i;
133 
134     bprm.p = TARGET_PAGE_SIZE * MAX_ARG_PAGES - sizeof(unsigned int);
135     for (i = 0 ; i < MAX_ARG_PAGES ; i++) {     /* clear page-table */
136             bprm.page[i] = NULL;
137     }
138     retval = open(filename, O_RDONLY);
139     if (retval < 0) {
140         return retval;
141     }
142     bprm.fd = retval;
143     bprm.filename = (char *)filename;
144     bprm.argc = count(argv);
145     bprm.argv = argv;
146     bprm.envc = count(envp);
147     bprm.envp = envp;
148 
149     retval = prepare_binprm(&bprm);
150 
151     if (retval >= 0) {
152         if (bprm.buf[0] == 0x7f
153                 && bprm.buf[1] == 'E'
154                 && bprm.buf[2] == 'L'
155                 && bprm.buf[3] == 'F') {
156             retval = load_elf_binary(&bprm, regs, infop);
157         } else {
158             fprintf(stderr, "Unknown binary format\n");
159             return -1;
160         }
161     }
162 
163     if (retval >= 0) {
164         /* success.  Initialize important registers */
165         do_init_thread(regs, infop);
166         return retval;
167     }
168 
169     /* Something went wrong, return the inode and free the argument pages*/
170     for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
171         g_free(bprm.page[i]);
172     }
173     return retval;
174 }
175