Merge tag 'pull-target-arm-20220812' of https://git.linaro.org/people/pmaydell/qemu...
[qemu.git] / linux-user / linuxload.c
1 /* Code for loading Linux executables. Mostly linux kernel code. */
2
3 #include "qemu/osdep.h"
4 #include "qemu.h"
5 #include "user-internals.h"
6 #include "loader.h"
7
8 #define NGROUPS 32
9
10 /* ??? This should really be somewhere else. */
11 abi_long memcpy_to_target(abi_ulong dest, const void *src, 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 return i;
32 }
33
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. */
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 ts->info->envp = envp;
96 ts->info->envc = envc;
97 ts->info->argv = argv;
98 ts->info->argc = argc;
99
100 if (push_ptr) {
101 /* FIXME - handle put_user() failures */
102 sp -= n;
103 put_user_ual(envp, sp);
104 sp -= n;
105 put_user_ual(argv, sp);
106 }
107
108 sp -= n;
109 /* FIXME - handle put_user() failures */
110 put_user_ual(argc, sp);
111
112 ts->info->arg_strings = stringp;
113 while (argc-- > 0) {
114 /* FIXME - handle put_user() failures */
115 put_user_ual(stringp, argv);
116 argv += n;
117 stringp += target_strlen(stringp) + 1;
118 }
119 /* FIXME - handle put_user() failures */
120 put_user_ual(0, argv);
121
122 ts->info->env_strings = stringp;
123 while (envc-- > 0) {
124 /* FIXME - handle put_user() failures */
125 put_user_ual(stringp, envp);
126 envp += n;
127 stringp += target_strlen(stringp) + 1;
128 }
129 /* FIXME - handle put_user() failures */
130 put_user_ual(0, envp);
131
132 return sp;
133 }
134
135 int loader_exec(int fdexec, const char *filename, char **argv, char **envp,
136 struct target_pt_regs *regs, struct image_info *infop,
137 struct linux_binprm *bprm)
138 {
139 int retval;
140
141 bprm->fd = fdexec;
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, infop);
156 #if defined(TARGET_HAS_BFLT)
157 } else if (bprm->buf[0] == 'b'
158 && bprm->buf[1] == 'F'
159 && bprm->buf[2] == 'L'
160 && bprm->buf[3] == 'T') {
161 retval = load_flt_binary(bprm, infop);
162 #endif
163 } else {
164 return -ENOEXEC;
165 }
166 }
167
168 if (retval >= 0) {
169 /* success. Initialize important registers */
170 do_init_thread(regs, infop);
171 return retval;
172 }
173
174 return retval;
175 }