2 * ----------------------------------------------------------------------------
3 * "THE BEER-WARE LICENSE" (Revision 42):
4 * <phk@FreeBSD.org> wrote this file. As long as you retain this notice you
5 * can do whatever you want with this stuff. If we meet some day, and you think
6 * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp
7 * ----------------------------------------------------------------------------
11 * This module handles execution of a.out files which have been run through
12 * "gzip". This saves diskspace, but wastes cpu-cycles and VM.
15 * text-segments should be made R/O after being filled
16 * is the vm-stuff safe ?
17 * should handle the entire header of gzip'ed stuff.
18 * inflate isn't quite reentrant yet...
19 * error-handling is a mess...
21 * tidy up unnecesary includes
24 #include <sys/cdefs.h>
25 __FBSDID("$FreeBSD$");
27 #include <sys/param.h>
29 #include <sys/imgact.h>
30 #include <sys/imgact_aout.h>
31 #include <sys/kernel.h>
34 #include <sys/mutex.h>
36 #include <sys/resourcevar.h>
37 #include <sys/sysent.h>
38 #include <sys/systm.h>
39 #include <sys/vnode.h>
40 #include <sys/inflate.h>
43 #include <vm/vm_param.h>
45 #include <vm/vm_map.h>
46 #include <vm/vm_kern.h>
47 #include <vm/vm_extern.h>
50 struct image_params *ip;
60 u_long virtual_offset, file_offset, file_end, bss_size;
63 static int exec_gzip_imgact(struct image_params *imgp);
64 static int NextByte(void *vp);
65 static int do_aout_hdr(struct imgact_gzip *);
66 static int Flush(void *vp, u_char *, u_long siz);
69 exec_gzip_imgact(imgp)
70 struct image_params *imgp;
72 int error, error2 = 0;
73 const u_char *p = (const u_char *) imgp->image_header;
74 struct imgact_gzip igz;
76 struct vmspace *vmspace;
78 /* If these four are not OK, it isn't a gzip file */
80 return -1; /* 0 Simply magic */
82 return -1; /* 1 Simply magic */
84 return -1; /* 2 Compression method */
86 return -1; /* 9 OS compressed on */
89 * If this one contains anything but a comment or a filename marker,
90 * we don't want to chew on it
93 return ENOEXEC; /* 3 Flags */
95 /* These are of no use to us */
99 bzero(&igz, sizeof igz);
100 bzero(&infl, sizeof infl);
101 infl.gz_private = (void *) &igz;
102 infl.gz_input = NextByte;
103 infl.gz_output = Flush;
108 if (p[3] & 0x08) { /* skip a filename */
110 if (igz.idx >= PAGE_SIZE)
113 if (p[3] & 0x10) { /* skip a comment */
115 if (igz.idx >= PAGE_SIZE)
118 igz.len = imgp->attr->va_size;
120 error = inflate(&infl);
123 * The unzipped file may not even have been long enough to contain
124 * a header giving Flush() a chance to return error. Check for this.
126 if ( !igz.gotheader )
130 vmspace = imgp->proc->p_vmspace;
131 error = vm_map_protect(&vmspace->vm_map,
132 (vm_offset_t) vmspace->vm_taddr,
133 (vm_offset_t) (vmspace->vm_taddr +
134 (vmspace->vm_tsize << PAGE_SHIFT)) ,
135 VM_PROT_READ|VM_PROT_EXECUTE,0);
140 vm_map_remove(kernel_map, (vm_offset_t) igz.inbuf,
141 (vm_offset_t) igz.inbuf + PAGE_SIZE);
143 if (igz.error || error || error2) {
144 printf("Output=%lu ", igz.output);
145 printf("Inflate_error=%d igz.error=%d error2=%d where=%d\n",
146 error, igz.error, error2, igz.where);
158 do_aout_hdr(struct imgact_gzip * gz)
161 struct thread *td = curthread;
162 struct vmspace *vmspace;
166 * Set file/virtual offset based on a.out variant. We do two cases:
167 * host byte order and network byte order (for NetBSD compatibility)
169 switch ((int) (gz->a_out.a_magic & 0xffff)) {
171 gz->virtual_offset = 0;
172 if (gz->a_out.a_text) {
173 gz->file_offset = PAGE_SIZE;
175 /* Bill's "screwball mode" */
180 gz->virtual_offset = PAGE_SIZE;
184 /* NetBSD compatibility */
185 switch ((int) (ntohl(gz->a_out.a_magic) & 0xffff)) {
188 gz->virtual_offset = PAGE_SIZE;
192 gz->where = __LINE__;
197 gz->bss_size = roundup(gz->a_out.a_bss, PAGE_SIZE);
200 * Check various fields in header for validity/bounds.
202 if ( /* entry point must lay with text region */
203 gz->a_out.a_entry < gz->virtual_offset ||
204 gz->a_out.a_entry >= gz->virtual_offset + gz->a_out.a_text ||
206 /* text and data size must each be page rounded */
207 gz->a_out.a_text & PAGE_MASK || gz->a_out.a_data & PAGE_MASK) {
208 gz->where = __LINE__;
212 * text/data/bss must not exceed limits
214 PROC_LOCK(gz->ip->proc);
215 if ( /* text can't exceed maximum text size */
216 gz->a_out.a_text > maxtsiz ||
218 /* data + bss can't exceed rlimit */
219 gz->a_out.a_data + gz->bss_size >
220 lim_cur(gz->ip->proc, RLIMIT_DATA)) {
221 PROC_UNLOCK(gz->ip->proc);
222 gz->where = __LINE__;
225 PROC_UNLOCK(gz->ip->proc);
226 /* Find out how far we should go */
227 gz->file_end = gz->file_offset + gz->a_out.a_text + gz->a_out.a_data;
230 * Avoid a possible deadlock if the current address space is destroyed
231 * and that address space maps the locked vnode. In the common case,
232 * the locked vnode's v_usecount is decremented but remains greater
233 * than zero. Consequently, the vnode lock is not needed by vrele().
234 * However, in cases where the vnode lock is external, such as nullfs,
235 * v_usecount may become zero.
237 VOP_UNLOCK(gz->ip->vp, 0, td);
240 * Destroy old process VM and create a new one (with a new stack)
242 exec_new_vmspace(gz->ip, &aout_sysvec);
244 vn_lock(gz->ip->vp, LK_EXCLUSIVE | LK_RETRY, td);
246 vmspace = gz->ip->proc->p_vmspace;
248 vmaddr = gz->virtual_offset;
250 error = vm_mmap(&vmspace->vm_map,
252 gz->a_out.a_text + gz->a_out.a_data,
253 VM_PROT_ALL, VM_PROT_ALL, MAP_ANON | MAP_FIXED,
259 gz->where = __LINE__;
263 if (gz->bss_size != 0) {
265 * Allocate demand-zeroed area for uninitialized data.
266 * "bss" = 'block started by symbol' - named after the
267 * IBM 7090 instruction of the same name.
269 vmaddr = gz->virtual_offset + gz->a_out.a_text +
271 error = vm_map_find(&vmspace->vm_map,
276 FALSE, VM_PROT_ALL, VM_PROT_ALL, 0);
278 gz->where = __LINE__;
282 /* Fill in process VM information */
283 vmspace->vm_tsize = gz->a_out.a_text >> PAGE_SHIFT;
284 vmspace->vm_dsize = (gz->a_out.a_data + gz->bss_size) >> PAGE_SHIFT;
285 vmspace->vm_taddr = (caddr_t) (uintptr_t) gz->virtual_offset;
286 vmspace->vm_daddr = (caddr_t) (uintptr_t)
287 (gz->virtual_offset + gz->a_out.a_text);
289 /* Fill in image_params */
290 gz->ip->interpreted = 0;
291 gz->ip->entry_addr = gz->a_out.a_entry;
293 gz->ip->proc->p_sysent = &aout_sysvec;
302 struct imgact_gzip *igz = (struct imgact_gzip *) vp;
304 if (igz->idx >= igz->len) {
305 igz->where = __LINE__;
308 if (igz->inbuf && igz->idx < (igz->offset + PAGE_SIZE)) {
309 return igz->inbuf[(igz->idx++) - igz->offset];
312 error = vm_map_remove(kernel_map, (vm_offset_t) igz->inbuf,
313 (vm_offset_t) igz->inbuf + PAGE_SIZE);
315 igz->where = __LINE__;
320 igz->offset = igz->idx & ~PAGE_MASK;
322 error = vm_mmap(kernel_map, /* map */
323 (vm_offset_t *) & igz->inbuf, /* address */
324 PAGE_SIZE, /* size */
325 VM_PROT_READ, /* protection */
326 VM_PROT_READ, /* max protection */
328 OBJT_VNODE, /* handle type */
329 igz->ip->vp, /* vnode */
330 igz->offset); /* offset */
332 igz->where = __LINE__;
336 return igz->inbuf[(igz->idx++) - igz->offset];
340 Flush(void *vp, u_char * ptr, u_long siz)
342 struct imgact_gzip *gz = (struct imgact_gzip *) vp;
346 /* First, find an a.out-header. */
347 if (gz->output < sizeof gz->a_out) {
348 q = (u_char *) & gz->a_out;
349 i = min(siz, sizeof gz->a_out - gz->output);
350 bcopy(p, q + gz->output, i);
354 if (gz->output == sizeof gz->a_out) {
359 gz->where = __LINE__;
363 gz->where = __LINE__;
367 if (gz->file_offset == 0) {
368 q = (u_char *) (uintptr_t) gz->virtual_offset;
369 copyout(&gz->a_out, q, sizeof gz->a_out);
373 /* Skip over zero-padded first PAGE if needed */
374 if (gz->output < gz->file_offset &&
375 gz->output + siz > gz->file_offset) {
376 i = min(siz, gz->file_offset - gz->output);
381 if (gz->output >= gz->file_offset && gz->output < gz->file_end) {
382 i = min(siz, gz->file_end - gz->output);
383 q = (u_char *) (uintptr_t)
384 (gz->virtual_offset + gz->output - gz->file_offset);
396 * Tell kern_execve.c about it, with a little help from the linker.
398 static struct execsw gzip_execsw = {exec_gzip_imgact, "gzip"};
399 EXEC_SET(execgzip, gzip_execsw);