imgact_gzip.c revision 153698
1139804Simp/*- 23332Sphk * ---------------------------------------------------------------------------- 33332Sphk * "THE BEER-WARE LICENSE" (Revision 42): 493149Sphk * <phk@FreeBSD.org> wrote this file. As long as you retain this notice you 53332Sphk * can do whatever you want with this stuff. If we meet some day, and you think 63332Sphk * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp 73332Sphk * ---------------------------------------------------------------------------- 8139804Simp */ 9139804Simp 10139804Simp/* 113332Sphk * This module handles execution of a.out files which have been run through 123784Sphk * "gzip". This saves diskspace, but wastes cpu-cycles and VM. 133332Sphk * 143332Sphk * TODO: 153332Sphk * text-segments should be made R/O after being filled 163332Sphk * is the vm-stuff safe ? 173332Sphk * should handle the entire header of gzip'ed stuff. 183332Sphk * inflate isn't quite reentrant yet... 193332Sphk * error-handling is a mess... 203332Sphk * so is the rest... 213417Scsgr * tidy up unnecesary includes 223332Sphk */ 233332Sphk 24116182Sobrien#include <sys/cdefs.h> 25116182Sobrien__FBSDID("$FreeBSD: head/sys/kern/imgact_gzip.c 153698 2005-12-24 04:57:50Z alc $"); 26116182Sobrien 273784Sphk#include <sys/param.h> 283332Sphk#include <sys/exec.h> 293332Sphk#include <sys/imgact.h> 303332Sphk#include <sys/imgact_aout.h> 313332Sphk#include <sys/kernel.h> 3276166Smarkm#include <sys/lock.h> 333507Scsgr#include <sys/mman.h> 3476166Smarkm#include <sys/mutex.h> 3515494Sbde#include <sys/proc.h> 363507Scsgr#include <sys/resourcevar.h> 373332Sphk#include <sys/sysent.h> 383507Scsgr#include <sys/systm.h> 3915494Sbde#include <sys/vnode.h> 403784Sphk#include <sys/inflate.h> 413332Sphk 423332Sphk#include <vm/vm.h> 4312662Sdg#include <vm/vm_param.h> 4412662Sdg#include <vm/pmap.h> 4512662Sdg#include <vm/vm_map.h> 463332Sphk#include <vm/vm_kern.h> 4712662Sdg#include <vm/vm_extern.h> 483332Sphk 493784Sphkstruct imgact_gzip { 503784Sphk struct image_params *ip; 513784Sphk struct exec a_out; 523784Sphk int error; 5348079Shoek int gotheader; 543784Sphk int where; 553784Sphk u_char *inbuf; 563784Sphk u_long offset; 573784Sphk u_long output; 583784Sphk u_long len; 593784Sphk int idx; 603784Sphk u_long virtual_offset, file_offset, file_end, bss_size; 613784Sphk}; 623784Sphk 6392723Salfredstatic int exec_gzip_imgact(struct image_params *imgp); 6492723Salfredstatic int NextByte(void *vp); 6592723Salfredstatic int do_aout_hdr(struct imgact_gzip *); 6692723Salfredstatic int Flush(void *vp, u_char *, u_long siz); 673784Sphk 6812568Sbdestatic int 6912130Sdgexec_gzip_imgact(imgp) 7012130Sdg struct image_params *imgp; 713332Sphk{ 723784Sphk int error, error2 = 0; 7317974Sbde const u_char *p = (const u_char *) imgp->image_header; 743784Sphk struct imgact_gzip igz; 753784Sphk struct inflate infl; 7617386Sphk struct vmspace *vmspace; 773332Sphk 783348Sphk /* If these four are not OK, it isn't a gzip file */ 793784Sphk if (p[0] != 0x1f) 803784Sphk return -1; /* 0 Simply magic */ 813784Sphk if (p[1] != 0x8b) 823784Sphk return -1; /* 1 Simply magic */ 833784Sphk if (p[2] != 0x08) 843784Sphk return -1; /* 2 Compression method */ 853784Sphk if (p[9] != 0x03) 863784Sphk return -1; /* 9 OS compressed on */ 873332Sphk 883784Sphk /* 893784Sphk * If this one contains anything but a comment or a filename marker, 903784Sphk * we don't want to chew on it 913348Sphk */ 923784Sphk if (p[3] & ~(0x18)) 933784Sphk return ENOEXEC; /* 3 Flags */ 943332Sphk 953348Sphk /* These are of no use to us */ 963784Sphk /* 4-7 Timestamp */ 973784Sphk /* 8 Extra flags */ 983348Sphk 993784Sphk bzero(&igz, sizeof igz); 1003784Sphk bzero(&infl, sizeof infl); 1013784Sphk infl.gz_private = (void *) &igz; 1023784Sphk infl.gz_input = NextByte; 1033784Sphk infl.gz_output = Flush; 1043332Sphk 10512130Sdg igz.ip = imgp; 1063784Sphk igz.idx = 10; 1073353Sphk 1083784Sphk if (p[3] & 0x08) { /* skip a filename */ 1093784Sphk while (p[igz.idx++]) 1103784Sphk if (igz.idx >= PAGE_SIZE) 1113784Sphk return ENOEXEC; 1123348Sphk } 1133784Sphk if (p[3] & 0x10) { /* skip a comment */ 1143784Sphk while (p[igz.idx++]) 1153784Sphk if (igz.idx >= PAGE_SIZE) 1163784Sphk return ENOEXEC; 1173348Sphk } 11817386Sphk igz.len = imgp->attr->va_size; 1193332Sphk 1203784Sphk error = inflate(&infl); 1213348Sphk 12248079Shoek /* 12348079Shoek * The unzipped file may not even have been long enough to contain 12448079Shoek * a header giving Flush() a chance to return error. Check for this. 12548079Shoek */ 12648079Shoek if ( !igz.gotheader ) 12748079Shoek return ENOEXEC; 12848079Shoek 12917386Sphk if ( !error ) { 13017386Sphk vmspace = imgp->proc->p_vmspace; 13117386Sphk error = vm_map_protect(&vmspace->vm_map, 13217386Sphk (vm_offset_t) vmspace->vm_taddr, 13317386Sphk (vm_offset_t) (vmspace->vm_taddr + 13417386Sphk (vmspace->vm_tsize << PAGE_SHIFT)) , 13517386Sphk VM_PROT_READ|VM_PROT_EXECUTE,0); 13617386Sphk } 13717386Sphk 1383784Sphk if (igz.inbuf) { 1393784Sphk error2 = 1406579Sdg vm_map_remove(kernel_map, (vm_offset_t) igz.inbuf, 1416579Sdg (vm_offset_t) igz.inbuf + PAGE_SIZE); 1423332Sphk } 1433784Sphk if (igz.error || error || error2) { 1443784Sphk printf("Output=%lu ", igz.output); 1453784Sphk printf("Inflate_error=%d igz.error=%d error2=%d where=%d\n", 1463784Sphk error, igz.error, error2, igz.where); 1473348Sphk } 1483784Sphk if (igz.error) 1493784Sphk return igz.error; 1503784Sphk if (error) 1513784Sphk return ENOEXEC; 1528876Srgrimes if (error2) 1533784Sphk return error2; 1543784Sphk return 0; 1553332Sphk} 1563332Sphk 1573784Sphkstatic int 1583784Sphkdo_aout_hdr(struct imgact_gzip * gz) 1593332Sphk{ 1603784Sphk int error; 161153698Salc struct thread *td = curthread; 16224848Sdyson struct vmspace *vmspace; 16314703Sbde vm_offset_t vmaddr; 1643332Sphk 1653784Sphk /* 1663784Sphk * Set file/virtual offset based on a.out variant. We do two cases: 1673784Sphk * host byte order and network byte order (for NetBSD compatibility) 1683784Sphk */ 1693784Sphk switch ((int) (gz->a_out.a_magic & 0xffff)) { 1703332Sphk case ZMAGIC: 1713784Sphk gz->virtual_offset = 0; 1723784Sphk if (gz->a_out.a_text) { 17315538Sphk gz->file_offset = PAGE_SIZE; 1743784Sphk } else { 1753784Sphk /* Bill's "screwball mode" */ 1763784Sphk gz->file_offset = 0; 1773784Sphk } 1783784Sphk break; 1793332Sphk case QMAGIC: 18015538Sphk gz->virtual_offset = PAGE_SIZE; 1813784Sphk gz->file_offset = 0; 1823784Sphk break; 1833332Sphk default: 1843784Sphk /* NetBSD compatibility */ 1853784Sphk switch ((int) (ntohl(gz->a_out.a_magic) & 0xffff)) { 1863784Sphk case ZMAGIC: 1873784Sphk case QMAGIC: 18815538Sphk gz->virtual_offset = PAGE_SIZE; 1893784Sphk gz->file_offset = 0; 1903784Sphk break; 1913784Sphk default: 1923784Sphk gz->where = __LINE__; 1933784Sphk return (-1); 1943784Sphk } 1953332Sphk } 1963332Sphk 19715538Sphk gz->bss_size = roundup(gz->a_out.a_bss, PAGE_SIZE); 1983332Sphk 1993784Sphk /* 2003784Sphk * Check various fields in header for validity/bounds. 2013784Sphk */ 2023784Sphk if ( /* entry point must lay with text region */ 2033784Sphk gz->a_out.a_entry < gz->virtual_offset || 2043784Sphk gz->a_out.a_entry >= gz->virtual_offset + gz->a_out.a_text || 2053332Sphk 2063332Sphk /* text and data size must each be page rounded */ 20715538Sphk gz->a_out.a_text & PAGE_MASK || gz->a_out.a_data & PAGE_MASK) { 2083784Sphk gz->where = __LINE__; 2093784Sphk return (-1); 2103784Sphk } 2113784Sphk /* 2123784Sphk * text/data/bss must not exceed limits 2133784Sphk */ 214125454Sjhb PROC_LOCK(gz->ip->proc); 2153784Sphk if ( /* text can't exceed maximum text size */ 21684783Sps gz->a_out.a_text > maxtsiz || 2173332Sphk 2183332Sphk /* data + bss can't exceed rlimit */ 2193784Sphk gz->a_out.a_data + gz->bss_size > 220125454Sjhb lim_cur(gz->ip->proc, RLIMIT_DATA)) { 221125454Sjhb PROC_UNLOCK(gz->ip->proc); 2223784Sphk gz->where = __LINE__; 2233784Sphk return (ENOMEM); 2243784Sphk } 225125454Sjhb PROC_UNLOCK(gz->ip->proc); 2263784Sphk /* Find out how far we should go */ 2273784Sphk gz->file_end = gz->file_offset + gz->a_out.a_text + gz->a_out.a_data; 2283332Sphk 2293784Sphk /* 230153698Salc * Avoid a possible deadlock if the current address space is destroyed 231153698Salc * and that address space maps the locked vnode. In the common case, 232153698Salc * the locked vnode's v_usecount is decremented but remains greater 233153698Salc * than zero. Consequently, the vnode lock is not needed by vrele(). 234153698Salc * However, in cases where the vnode lock is external, such as nullfs, 235153698Salc * v_usecount may become zero. 236153698Salc */ 237153698Salc VOP_UNLOCK(gz->ip->vp, 0, td); 238153698Salc 239153698Salc /* 2403784Sphk * Destroy old process VM and create a new one (with a new stack) 2413784Sphk */ 242103767Sjake exec_new_vmspace(gz->ip, &aout_sysvec); 2433348Sphk 244153698Salc vn_lock(gz->ip->vp, LK_EXCLUSIVE | LK_RETRY, td); 245153698Salc 24624848Sdyson vmspace = gz->ip->proc->p_vmspace; 24724848Sdyson 2483784Sphk vmaddr = gz->virtual_offset; 2493332Sphk 2503784Sphk error = vm_mmap(&vmspace->vm_map, 2513784Sphk &vmaddr, 25217386Sphk gz->a_out.a_text + gz->a_out.a_data, 25317386Sphk VM_PROT_ALL, VM_PROT_ALL, MAP_ANON | MAP_FIXED, 254144501Sjhb OBJT_DEFAULT, 255144501Sjhb NULL, 2563784Sphk 0); 2573332Sphk 2583784Sphk if (error) { 2593784Sphk gz->where = __LINE__; 2603784Sphk return (error); 2613784Sphk } 26217386Sphk 2636579Sdg if (gz->bss_size != 0) { 2646579Sdg /* 26514087Sphk * Allocate demand-zeroed area for uninitialized data. 26614087Sphk * "bss" = 'block started by symbol' - named after the 26714087Sphk * IBM 7090 instruction of the same name. 2686579Sdg */ 26914087Sphk vmaddr = gz->virtual_offset + gz->a_out.a_text + 27014087Sphk gz->a_out.a_data; 27117386Sphk error = vm_map_find(&vmspace->vm_map, 27217386Sphk NULL, 27317386Sphk 0, 27417386Sphk &vmaddr, 27517386Sphk gz->bss_size, 27617386Sphk FALSE, VM_PROT_ALL, VM_PROT_ALL, 0); 2776579Sdg if (error) { 2786579Sdg gz->where = __LINE__; 2796579Sdg return (error); 2806579Sdg } 2813784Sphk } 2823784Sphk /* Fill in process VM information */ 2833784Sphk vmspace->vm_tsize = gz->a_out.a_text >> PAGE_SHIFT; 2843784Sphk vmspace->vm_dsize = (gz->a_out.a_data + gz->bss_size) >> PAGE_SHIFT; 28537656Sbde vmspace->vm_taddr = (caddr_t) (uintptr_t) gz->virtual_offset; 28637656Sbde vmspace->vm_daddr = (caddr_t) (uintptr_t) 28737656Sbde (gz->virtual_offset + gz->a_out.a_text); 2883332Sphk 2893784Sphk /* Fill in image_params */ 2903784Sphk gz->ip->interpreted = 0; 2913784Sphk gz->ip->entry_addr = gz->a_out.a_entry; 2923332Sphk 2933784Sphk gz->ip->proc->p_sysent = &aout_sysvec; 2943332Sphk 2953784Sphk return 0; 2963784Sphk} 2973332Sphk 2983784Sphkstatic int 2993784SphkNextByte(void *vp) 3003784Sphk{ 3013784Sphk int error; 3023784Sphk struct imgact_gzip *igz = (struct imgact_gzip *) vp; 3033332Sphk 3043784Sphk if (igz->idx >= igz->len) { 3053784Sphk igz->where = __LINE__; 3063784Sphk return GZ_EOF; 3073784Sphk } 3083784Sphk if (igz->inbuf && igz->idx < (igz->offset + PAGE_SIZE)) { 3093784Sphk return igz->inbuf[(igz->idx++) - igz->offset]; 3103784Sphk } 3113784Sphk if (igz->inbuf) { 3126579Sdg error = vm_map_remove(kernel_map, (vm_offset_t) igz->inbuf, 3136579Sdg (vm_offset_t) igz->inbuf + PAGE_SIZE); 3143784Sphk if (error) { 3153784Sphk igz->where = __LINE__; 3163784Sphk igz->error = error; 3173784Sphk return GZ_EOF; 3183784Sphk } 3193784Sphk } 3206342Sphk igz->offset = igz->idx & ~PAGE_MASK; 3213332Sphk 3223784Sphk error = vm_mmap(kernel_map, /* map */ 3233784Sphk (vm_offset_t *) & igz->inbuf, /* address */ 3243784Sphk PAGE_SIZE, /* size */ 3253784Sphk VM_PROT_READ, /* protection */ 3263784Sphk VM_PROT_READ, /* max protection */ 3273784Sphk 0, /* flags */ 328144501Sjhb OBJT_VNODE, /* handle type */ 329144501Sjhb igz->ip->vp, /* vnode */ 3303784Sphk igz->offset); /* offset */ 3313784Sphk if (error) { 3323784Sphk igz->where = __LINE__; 3333784Sphk igz->error = error; 3343784Sphk return GZ_EOF; 3353784Sphk } 3363784Sphk return igz->inbuf[(igz->idx++) - igz->offset]; 3373784Sphk} 3383332Sphk 3393784Sphkstatic int 3403784SphkFlush(void *vp, u_char * ptr, u_long siz) 3413784Sphk{ 3423784Sphk struct imgact_gzip *gz = (struct imgact_gzip *) vp; 3433784Sphk u_char *p = ptr, *q; 3443784Sphk int i; 3453348Sphk 346108533Sschweikh /* First, find an a.out-header. */ 3473784Sphk if (gz->output < sizeof gz->a_out) { 3483784Sphk q = (u_char *) & gz->a_out; 3493784Sphk i = min(siz, sizeof gz->a_out - gz->output); 3503784Sphk bcopy(p, q + gz->output, i); 3513784Sphk gz->output += i; 3523784Sphk p += i; 3533784Sphk siz -= i; 3543784Sphk if (gz->output == sizeof gz->a_out) { 35548079Shoek gz->gotheader = 1; 3563784Sphk i = do_aout_hdr(gz); 3573784Sphk if (i == -1) { 3583785Sphk if (!gz->where) 3593785Sphk gz->where = __LINE__; 3603784Sphk gz->error = ENOEXEC; 3613784Sphk return ENOEXEC; 3623784Sphk } else if (i) { 3633784Sphk gz->where = __LINE__; 3643784Sphk gz->error = i; 3653784Sphk return ENOEXEC; 3663784Sphk } 36731718Sjdp if (gz->file_offset == 0) { 36837656Sbde q = (u_char *) (uintptr_t) gz->virtual_offset; 36937015Sbde copyout(&gz->a_out, q, sizeof gz->a_out); 3703784Sphk } 3713784Sphk } 3723784Sphk } 3733784Sphk /* Skip over zero-padded first PAGE if needed */ 37437015Sbde if (gz->output < gz->file_offset && 37537015Sbde gz->output + siz > gz->file_offset) { 3763784Sphk i = min(siz, gz->file_offset - gz->output); 3773784Sphk gz->output += i; 3783784Sphk p += i; 3793784Sphk siz -= i; 3803784Sphk } 3813784Sphk if (gz->output >= gz->file_offset && gz->output < gz->file_end) { 3823784Sphk i = min(siz, gz->file_end - gz->output); 38337656Sbde q = (u_char *) (uintptr_t) 38437656Sbde (gz->virtual_offset + gz->output - gz->file_offset); 38537015Sbde copyout(p, q, i); 3863784Sphk gz->output += i; 3873784Sphk p += i; 3883784Sphk siz -= i; 3893784Sphk } 3903784Sphk gz->output += siz; 3913784Sphk return 0; 3923332Sphk} 3933332Sphk 3943784Sphk 3953332Sphk/* 3963332Sphk * Tell kern_execve.c about it, with a little help from the linker. 3973332Sphk */ 39843402Sdillonstatic struct execsw gzip_execsw = {exec_gzip_imgact, "gzip"}; 39940435SpeterEXEC_SET(execgzip, gzip_execsw); 400