/*- * Copyright (c) 1995-1996 Søren Schmidt * Copyright (c) 1996 Peter Wemm * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer * in this position and unchanged. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote products * derived from this software withough specific prior written permission * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * $FreeBSD: src/sys/kern/imgact_elf.c,v 1.73.2.13 2002/12/28 19:49:41 dillon Exp $ * $DragonFly: src/sys/kern/imgact_elf.c,v 1.55 2008/08/17 17:21:36 nth Exp $ */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define OLD_EI_BRAND 8 __ElfType(Brandinfo); __ElfType(Auxargs); static int elf_check_header (const Elf_Ehdr *hdr); static int elf_freebsd_fixup (register_t **stack_base, struct image_params *imgp); static int elf_load_file (struct proc *p, const char *file, u_long *addr, u_long *entry); static int elf_load_section (struct proc *p, struct vmspace *vmspace, struct vnode *vp, vm_offset_t offset, caddr_t vmaddr, size_t memsz, size_t filsz, vm_prot_t prot); static int exec_elf_imgact (struct image_params *imgp); static int elf_trace = 0; SYSCTL_INT(_debug, OID_AUTO, elf_trace, CTLFLAG_RW, &elf_trace, 0, ""); static int elf_legacy_coredump = 0; SYSCTL_INT(_debug, OID_AUTO, elf_legacy_coredump, CTLFLAG_RW, &elf_legacy_coredump, 0, ""); static int dragonfly_match_abi_note(const Elf_Note *); static int freebsd_match_abi_note(const Elf_Note *); static struct sysentvec elf_freebsd_sysvec = { SYS_MAXSYSCALL, sysent, -1, 0, 0, 0, 0, 0, elf_freebsd_fixup, sendsig, sigcode, &szsigcode, 0, "FreeBSD ELF", elf_coredump, NULL, MINSIGSTKSZ }; static Elf_Brandinfo freebsd_brand_info = { ELFOSABI_FREEBSD, "FreeBSD", freebsd_match_abi_note, "", "/usr/libexec/ld-elf.so.1", &elf_freebsd_sysvec }; static Elf_Brandinfo dragonfly_brand_info = { ELFOSABI_NONE, "DragonFly", dragonfly_match_abi_note, "", "/usr/libexec/ld-elf.so.2", &elf_freebsd_sysvec }; static Elf_Brandinfo *elf_brand_list[MAX_BRANDS] = { &dragonfly_brand_info, &freebsd_brand_info, NULL, NULL, NULL, NULL, NULL, NULL }; static int freebsd_match_abi_note(const Elf_Note *abi_note) { const char *abi_name = (const char *) ((const uint8_t *)abi_note + sizeof(*abi_note)); if (abi_note->n_namesz != sizeof("FreeBSD")) return(FALSE); if (memcmp(abi_name, "FreeBSD", sizeof("FreeBSD"))) return(FALSE); return(TRUE); } static int dragonfly_match_abi_note(const Elf_Note *abi_note) { const char *abi_name = (const char *) ((const uint8_t *)abi_note + sizeof(*abi_note)); if (abi_note->n_namesz != sizeof("DragonFly")) return(FALSE); if (memcmp(abi_name, "DragonFly", sizeof("DragonFly"))) return(FALSE); return(TRUE); } int elf_insert_brand_entry(Elf_Brandinfo *entry) { int i; for (i=1; ip_sysent == info->entry->sysvec) { info->rval = TRUE; return(-1); } return(0); } static int elf_check_header(const Elf_Ehdr *hdr) { if (!IS_ELF(*hdr) || hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || hdr->e_ident[EI_DATA] != ELF_TARG_DATA || hdr->e_ident[EI_VERSION] != EV_CURRENT || hdr->e_phentsize != sizeof(Elf_Phdr) || hdr->e_ehsize != sizeof(Elf_Ehdr) || hdr->e_version != ELF_TARG_VER) return ENOEXEC; if (!ELF_MACHINE_OK(hdr->e_machine)) return ENOEXEC; return 0; } static int elf_load_section(struct proc *p, struct vmspace *vmspace, struct vnode *vp, vm_offset_t offset, caddr_t vmaddr, size_t memsz, size_t filsz, vm_prot_t prot) { size_t map_len; vm_offset_t map_addr; int error, rv, cow; int count; size_t copy_len; vm_object_t object; vm_offset_t file_addr; object = vp->v_object; error = 0; /* * It's necessary to fail if the filsz + offset taken from the * header is greater than the actual file pager object's size. * If we were to allow this, then the vm_map_find() below would * walk right off the end of the file object and into the ether. * * While I'm here, might as well check for something else that * is invalid: filsz cannot be greater than memsz. */ if ((off_t)filsz + offset > vp->v_filesize || filsz > memsz) { uprintf("elf_load_section: truncated ELF file\n"); return (ENOEXEC); } map_addr = trunc_page((vm_offset_t)vmaddr); file_addr = trunc_page(offset); /* * We have two choices. We can either clear the data in the last page * of an oversized mapping, or we can start the anon mapping a page * early and copy the initialized data into that first page. We * choose the second.. */ if (memsz > filsz) map_len = trunc_page(offset+filsz) - file_addr; else map_len = round_page(offset+filsz) - file_addr; if (map_len != 0) { vm_object_reference(object); /* cow flags: don't dump readonly sections in core */ cow = MAP_COPY_ON_WRITE | MAP_PREFAULT | (prot & VM_PROT_WRITE ? 0 : MAP_DISABLE_COREDUMP); count = vm_map_entry_reserve(MAP_RESERVE_COUNT); vm_map_lock(&vmspace->vm_map); rv = vm_map_insert(&vmspace->vm_map, &count, object, file_addr, /* file offset */ map_addr, /* virtual start */ map_addr + map_len,/* virtual end */ VM_MAPTYPE_NORMAL, prot, VM_PROT_ALL, cow); vm_map_unlock(&vmspace->vm_map); vm_map_entry_release(count); if (rv != KERN_SUCCESS) { vm_object_deallocate(object); return EINVAL; } /* we can stop now if we've covered it all */ if (memsz == filsz) { return 0; } } /* * We have to get the remaining bit of the file into the first part * of the oversized map segment. This is normally because the .data * segment in the file is extended to provide bss. It's a neat idea * to try and save a page, but it's a pain in the behind to implement. */ copy_len = (offset + filsz) - trunc_page(offset + filsz); map_addr = trunc_page((vm_offset_t)vmaddr + filsz); map_len = round_page((vm_offset_t)vmaddr + memsz) - map_addr; /* This had damn well better be true! */ if (map_len != 0) { count = vm_map_entry_reserve(MAP_RESERVE_COUNT); vm_map_lock(&vmspace->vm_map); rv = vm_map_insert(&vmspace->vm_map, &count, NULL, 0, map_addr, map_addr + map_len, VM_MAPTYPE_NORMAL, VM_PROT_ALL, VM_PROT_ALL, 0); vm_map_unlock(&vmspace->vm_map); vm_map_entry_release(count); if (rv != KERN_SUCCESS) { return EINVAL; } } if (copy_len != 0) { vm_page_t m; struct sf_buf *sf; m = vm_fault_object_page(object, trunc_page(offset + filsz), VM_PROT_READ, 0, &error); if (m) { sf = sf_buf_alloc(m, SFB_CPUPRIVATE); error = copyout((caddr_t)sf_buf_kva(sf), (caddr_t)map_addr, copy_len); sf_buf_free(sf); vm_page_unhold(m); } if (error) { return (error); } } /* * set it to the specified protection */ vm_map_protect(&vmspace->vm_map, map_addr, map_addr + map_len, prot, FALSE); return error; } /* * Load the file "file" into memory. It may be either a shared object * or an executable. * * The "addr" reference parameter is in/out. On entry, it specifies * the address where a shared object should be loaded. If the file is * an executable, this value is ignored. On exit, "addr" specifies * where the file was actually loaded. * * The "entry" reference parameter is out only. On exit, it specifies * the entry point for the loaded file. */ static int elf_load_file(struct proc *p, const char *file, u_long *addr, u_long *entry) { struct { struct nlookupdata nd; struct vattr attr; struct image_params image_params; } *tempdata; const Elf_Ehdr *hdr = NULL; const Elf_Phdr *phdr = NULL; struct nlookupdata *nd; struct vmspace *vmspace = p->p_vmspace; struct vattr *attr; struct image_params *imgp; vm_prot_t prot; u_long rbase; u_long base_addr = 0; int error, i, numsegs; tempdata = kmalloc(sizeof(*tempdata), M_TEMP, M_WAITOK); nd = &tempdata->nd; attr = &tempdata->attr; imgp = &tempdata->image_params; /* * Initialize part of the common data */ imgp->proc = p; imgp->attr = attr; imgp->firstpage = NULL; imgp->image_header = NULL; imgp->vp = NULL; error = nlookup_init(nd, file, UIO_SYSSPACE, NLC_FOLLOW); if (error == 0) error = nlookup(nd); if (error == 0) error = cache_vget(&nd->nl_nch, nd->nl_cred, LK_EXCLUSIVE, &imgp->vp); nlookup_done(nd); if (error) goto fail; /* * Check permissions, modes, uid, etc on the file, and "open" it. */ error = exec_check_permissions(imgp); if (error) { vn_unlock(imgp->vp); goto fail; } error = exec_map_first_page(imgp); /* * Also make certain that the interpreter stays the same, so set * its VTEXT flag, too. */ if (error == 0) imgp->vp->v_flag |= VTEXT; vn_unlock(imgp->vp); if (error) goto fail; hdr = (const Elf_Ehdr *)imgp->image_header; if ((error = elf_check_header(hdr)) != 0) goto fail; if (hdr->e_type == ET_DYN) rbase = *addr; else if (hdr->e_type == ET_EXEC) rbase = 0; else { error = ENOEXEC; goto fail; } /* Only support headers that fit within first page for now * (multiplication of two Elf_Half fields will not overflow) */ if ((hdr->e_phoff > PAGE_SIZE) || (hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE - hdr->e_phoff) { error = ENOEXEC; goto fail; } phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff); for (i = 0, numsegs = 0; i < hdr->e_phnum; i++) { if (phdr[i].p_type == PT_LOAD) { /* Loadable segment */ prot = 0; if (phdr[i].p_flags & PF_X) prot |= VM_PROT_EXECUTE; if (phdr[i].p_flags & PF_W) prot |= VM_PROT_WRITE; if (phdr[i].p_flags & PF_R) prot |= VM_PROT_READ; error = elf_load_section( p, vmspace, imgp->vp, phdr[i].p_offset, (caddr_t)phdr[i].p_vaddr + rbase, phdr[i].p_memsz, phdr[i].p_filesz, prot); if (error != 0) goto fail; /* * Establish the base address if this is the * first segment. */ if (numsegs == 0) base_addr = trunc_page(phdr[i].p_vaddr + rbase); numsegs++; } } *addr = base_addr; *entry=(unsigned long)hdr->e_entry + rbase; fail: if (imgp->firstpage) exec_unmap_first_page(imgp); if (imgp->vp) { vrele(imgp->vp); imgp->vp = NULL; } kfree(tempdata, M_TEMP); return error; } /* * non static, as it can be overridden by start_init() */ int fallback_elf_brand = -1; SYSCTL_INT(_kern, OID_AUTO, fallback_elf_brand, CTLFLAG_RW, &fallback_elf_brand, -1, "ELF brand of last resort"); static int exec_elf_imgact(struct image_params *imgp) { const Elf_Ehdr *hdr = (const Elf_Ehdr *) imgp->image_header; const Elf_Phdr *phdr; Elf_Auxargs *elf_auxargs = NULL; struct vmspace *vmspace; vm_prot_t prot; u_long text_size = 0, data_size = 0, total_size = 0; u_long text_addr = 0, data_addr = 0; u_long seg_size, seg_addr; u_long addr, entry = 0, proghdr = 0; int error, i; const char *interp = NULL; const Elf_Note *abi_note = NULL; Elf_Brandinfo *brand_info; char *path; error = 0; /* * Do we have a valid ELF header ? */ if (elf_check_header(hdr) != 0 || hdr->e_type != ET_EXEC) return -1; /* * From here on down, we return an errno, not -1, as we've * detected an ELF file. */ if ((hdr->e_phoff > PAGE_SIZE) || (hdr->e_phoff + hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE) { /* Only support headers in first page for now */ return ENOEXEC; } phdr = (const Elf_Phdr*)(imgp->image_header + hdr->e_phoff); /* * From this point on, we may have resources that need to be freed. */ exec_new_vmspace(imgp, NULL); /* * Yeah, I'm paranoid. There is every reason in the world to get * VTEXT now since from here on out, there are places we can have * a context switch. Better safe than sorry; I really don't want * the file to change while it's being loaded. */ vsetflags(imgp->vp, VTEXT); vmspace = imgp->proc->p_vmspace; for (i = 0; i < hdr->e_phnum; i++) { switch(phdr[i].p_type) { case PT_LOAD: /* Loadable segment */ prot = 0; if (phdr[i].p_flags & PF_X) prot |= VM_PROT_EXECUTE; if (phdr[i].p_flags & PF_W) prot |= VM_PROT_WRITE; if (phdr[i].p_flags & PF_R) prot |= VM_PROT_READ; if ((error = elf_load_section(imgp->proc, vmspace, imgp->vp, phdr[i].p_offset, (caddr_t)phdr[i].p_vaddr, phdr[i].p_memsz, phdr[i].p_filesz, prot)) != 0) goto fail; /* * If this segment contains the program headers, * remember their virtual address for the AT_PHDR * aux entry. Static binaries don't usually include * a PT_PHDR entry. */ if (phdr[i].p_offset == 0 && hdr->e_phoff + hdr->e_phnum * hdr->e_phentsize <= phdr[i].p_filesz) proghdr = phdr[i].p_vaddr + hdr->e_phoff; seg_addr = trunc_page(phdr[i].p_vaddr); seg_size = round_page(phdr[i].p_memsz + phdr[i].p_vaddr - seg_addr); /* * Is this .text or .data? We can't use * VM_PROT_WRITE or VM_PROT_EXEC, it breaks the * alpha terribly and possibly does other bad * things so we stick to the old way of figuring * it out: If the segment contains the program * entry point, it's a text segment, otherwise it * is a data segment. * * Note that obreak() assumes that data_addr + * data_size == end of data load area, and the ELF * file format expects segments to be sorted by * address. If multiple data segments exist, the * last one will be used. */ if (hdr->e_entry >= phdr[i].p_vaddr && hdr->e_entry < (phdr[i].p_vaddr + phdr[i].p_memsz)) { text_size = seg_size; text_addr = seg_addr; entry = (u_long)hdr->e_entry; } else { data_size = seg_size; data_addr = seg_addr; } total_size += seg_size; /* * Check limits. It should be safe to check the * limits after loading the segment since we do * not actually fault in all the segment's pages. */ if (data_size > imgp->proc->p_rlimit[RLIMIT_DATA].rlim_cur || text_size > maxtsiz || total_size > imgp->proc->p_rlimit[RLIMIT_VMEM].rlim_cur) { error = ENOMEM; goto fail; } break; case PT_INTERP: /* Path to interpreter */ if (phdr[i].p_filesz > MAXPATHLEN || phdr[i].p_offset + phdr[i].p_filesz > PAGE_SIZE) { error = ENOEXEC; goto fail; } interp = imgp->image_header + phdr[i].p_offset; break; case PT_NOTE: /* Check for .note.ABI-tag */ { const Elf_Note *tmp_note; /* XXX handle anything outside the first page */ if (phdr[i].p_offset + phdr[i].p_filesz > PAGE_SIZE) continue; if (phdr[i].p_filesz < sizeof(Elf_Note)) continue; /* ENOEXEC? */ tmp_note = (const Elf_Note *)(imgp->image_header + phdr[i].p_offset); if (tmp_note->n_type != 1) continue; if (tmp_note->n_namesz + sizeof(Elf_Note) + tmp_note->n_descsz > phdr[i].p_filesz) continue; /* ENOEXEC? */ abi_note = tmp_note; } break; case PT_PHDR: /* Program header table info */ proghdr = phdr[i].p_vaddr; break; default: break; } } vmspace->vm_tsize = text_size >> PAGE_SHIFT; vmspace->vm_taddr = (caddr_t)(uintptr_t)text_addr; vmspace->vm_dsize = data_size >> PAGE_SHIFT; vmspace->vm_daddr = (caddr_t)(uintptr_t)data_addr; addr = ELF_RTLD_ADDR(vmspace); imgp->entry_addr = entry; brand_info = NULL; /* We support three types of branding -- (1) the ELF EI_OSABI field * that SCO added to the ELF spec, (2) FreeBSD 3.x's traditional string * branding w/in the ELF header, and (3) path of the `interp_path' * field. We should also look for an ".note.ABI-tag" ELF section now * in all Linux ELF binaries, FreeBSD 4.1+, and some NetBSD ones. */ /* If the executable has a brand, search for it in the brand list. */ if (brand_info == NULL && hdr->e_ident[EI_OSABI] != ELFOSABI_NONE) { for (i = 0; i < MAX_BRANDS; i++) { Elf_Brandinfo *bi = elf_brand_list[i]; if (bi != NULL && (hdr->e_ident[EI_OSABI] == bi->brand || 0 == strncmp((const char *)&hdr->e_ident[OLD_EI_BRAND], bi->compat_3_brand, strlen(bi->compat_3_brand)))) { brand_info = bi; break; } } } /* Search for a recognized ABI. */ if (brand_info == NULL && abi_note != NULL) { for (i = 0; i < MAX_BRANDS; i++) { Elf_Brandinfo *bi = elf_brand_list[i]; if (bi != NULL && bi->match_abi_note != NULL && (*bi->match_abi_note)(abi_note)) { brand_info = bi; break; } } } /* * ELFOSABI_NONE == ELFOSABI_SYSV, so a SYSV binary misses all * checks so far, since it is neither branded nor does it have * an ABI note. If the EI_OSABI field is ELFOSABI_NONE, assume * it is svr4 and look for an entry in the elf_brand_list with * match_abi_note == NULL. */ if (brand_info == NULL && hdr->e_ident[EI_OSABI] == ELFOSABI_NONE) { for (i = 0; i < MAX_BRANDS; i++) { Elf_Brandinfo *bi = elf_brand_list[i]; if (bi != NULL && bi->match_abi_note == NULL && ELFOSABI_SYSV == bi->brand) { brand_info = bi; break; } } } /* Lacking a recognized ABI, search for a recognized interpreter. */ if (brand_info == NULL && interp != NULL) { for (i = 0; i < MAX_BRANDS; i++) { Elf_Brandinfo *bi = elf_brand_list[i]; if (bi != NULL && strcmp(interp, bi->interp_path) == 0) { brand_info = bi; break; } } } /* Lacking a recognized interpreter, try the default brand */ if (brand_info == NULL) { for (i = 0; i < MAX_BRANDS; i++) { Elf_Brandinfo *bi = elf_brand_list[i]; if (bi != NULL && fallback_elf_brand == bi->brand) { brand_info = bi; break; } } } if (brand_info == NULL) { uprintf("ELF binary type \"%u\" not known.\n", hdr->e_ident[EI_OSABI]); error = ENOEXEC; goto fail; } imgp->proc->p_sysent = brand_info->sysvec; if (interp != NULL) { path = kmalloc(MAXPATHLEN, M_TEMP, M_WAITOK); ksnprintf(path, MAXPATHLEN, "%s%s", brand_info->emul_path, interp); if ((error = elf_load_file(imgp->proc, path, &addr, &imgp->entry_addr)) != 0) { if ((error = elf_load_file(imgp->proc, interp, &addr, &imgp->entry_addr)) != 0) { uprintf("ELF interpreter %s not found\n", path); kfree(path, M_TEMP); goto fail; } } kfree(path, M_TEMP); } else { addr = 0; } /* * Construct auxargs table (used by the fixup routine) */ elf_auxargs = kmalloc(sizeof(Elf_Auxargs), M_TEMP, M_WAITOK); elf_auxargs->execfd = -1; elf_auxargs->phdr = proghdr; elf_auxargs->phent = hdr->e_phentsize; elf_auxargs->phnum = hdr->e_phnum; elf_auxargs->pagesz = PAGE_SIZE; elf_auxargs->base = addr; elf_auxargs->flags = 0; elf_auxargs->entry = entry; elf_auxargs->trace = elf_trace; imgp->auxargs = elf_auxargs; imgp->interpreted = 0; fail: return error; } static int elf_freebsd_fixup(register_t **stack_base, struct image_params *imgp) { Elf_Auxargs *args = (Elf_Auxargs *)imgp->auxargs; register_t *pos; pos = *stack_base + (imgp->args->argc + imgp->args->envc + 2); if (args->trace) { AUXARGS_ENTRY(pos, AT_DEBUG, 1); } if (args->execfd != -1) { AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd); } AUXARGS_ENTRY(pos, AT_PHDR, args->phdr); AUXARGS_ENTRY(pos, AT_PHENT, args->phent); AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum); AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz); AUXARGS_ENTRY(pos, AT_FLAGS, args->flags); AUXARGS_ENTRY(pos, AT_ENTRY, args->entry); AUXARGS_ENTRY(pos, AT_BASE, args->base); AUXARGS_ENTRY(pos, AT_NULL, 0); kfree(imgp->auxargs, M_TEMP); imgp->auxargs = NULL; (*stack_base)--; suword(*stack_base, (long) imgp->args->argc); return 0; } /* * Code for generating ELF core dumps. */ typedef int (*segment_callback) (vm_map_entry_t, void *); /* Closure for cb_put_phdr(). */ struct phdr_closure { Elf_Phdr *phdr; /* Program header to fill in (incremented) */ Elf_Phdr *phdr_max; /* Pointer bound for error check */ Elf_Off offset; /* Offset of segment in core file */ }; /* Closure for cb_size_segment(). */ struct sseg_closure { int count; /* Count of writable segments. */ size_t vsize; /* Total size of all writable segments. */ }; /* Closure for cb_put_fp(). */ struct fp_closure { struct vn_hdr *vnh; struct vn_hdr *vnh_max; int count; struct stat *sb; }; typedef struct elf_buf { char *buf; size_t off; size_t off_max; } *elf_buf_t; static void *target_reserve(elf_buf_t target, size_t bytes, int *error); static int cb_put_phdr (vm_map_entry_t, void *); static int cb_size_segment (vm_map_entry_t, void *); static int cb_fpcount_segment(vm_map_entry_t, void *); static int cb_put_fp(vm_map_entry_t, void *); static int each_segment (struct proc *, segment_callback, void *, int); static int elf_corehdr (struct lwp *, int, struct file *, struct ucred *, int, elf_buf_t); enum putmode { WRITE, DRYRUN }; static int elf_puthdr (struct lwp *, elf_buf_t, int sig, enum putmode, int, struct file *); static int elf_putallnotes(struct lwp *, elf_buf_t, int, enum putmode); static int elf_putnote (elf_buf_t, const char *, int, const void *, size_t); static int elf_putsigs(struct lwp *, elf_buf_t); static int elf_puttextvp(struct proc *, elf_buf_t); static int elf_putfiles(struct proc *, elf_buf_t, struct file *); extern int osreldate; int elf_coredump(struct lwp *lp, int sig, struct vnode *vp, off_t limit) { struct file *fp; int error; if ((error = falloc(NULL, &fp, NULL)) != 0) return (error); fsetcred(fp, lp->lwp_proc->p_ucred); /* * XXX fixme. */ fp->f_type = DTYPE_VNODE; fp->f_flag = O_CREAT|O_WRONLY|O_NOFOLLOW; fp->f_ops = &vnode_fileops; fp->f_data = vp; vn_unlock(vp); error = generic_elf_coredump(lp, sig, fp, limit); fp->f_type = 0; fp->f_flag = 0; fp->f_ops = &badfileops; fp->f_data = NULL; fdrop(fp); return (error); } int generic_elf_coredump(struct lwp *lp, int sig, struct file *fp, off_t limit) { struct proc *p = lp->lwp_proc; struct ucred *cred = p->p_ucred; int error = 0; struct sseg_closure seginfo; struct elf_buf target; if (!fp) kprintf("can't dump core - null fp\n"); /* * Size the program segments */ seginfo.count = 0; seginfo.vsize = 0; each_segment(p, cb_size_segment, &seginfo, 1); /* * Calculate the size of the core file header area by making * a dry run of generating it. Nothing is written, but the * size is calculated. */ bzero(&target, sizeof(target)); elf_puthdr(lp, &target, sig, DRYRUN, seginfo.count, fp); if (target.off + seginfo.vsize >= limit) return (EFAULT); /* * Allocate memory for building the header, fill it up, * and write it out. */ target.off_max = target.off; target.off = 0; target.buf = kmalloc(target.off_max, M_TEMP, M_WAITOK|M_ZERO); error = elf_corehdr(lp, sig, fp, cred, seginfo.count, &target); /* Write the contents of all of the writable segments. */ if (error == 0) { Elf_Phdr *php; int i; ssize_t nbytes; php = (Elf_Phdr *)(target.buf + sizeof(Elf_Ehdr)) + 1; for (i = 0; i < seginfo.count; i++) { error = fp_write(fp, (caddr_t)php->p_vaddr, php->p_filesz, &nbytes, UIO_USERSPACE); if (error != 0) break; php++; } } kfree(target.buf, M_TEMP); return error; } /* * A callback for each_segment() to write out the segment's * program header entry. */ static int cb_put_phdr(vm_map_entry_t entry, void *closure) { struct phdr_closure *phc = closure; Elf_Phdr *phdr = phc->phdr; if (phc->phdr == phc->phdr_max) return EINVAL; phc->offset = round_page(phc->offset); phdr->p_type = PT_LOAD; phdr->p_offset = phc->offset; phdr->p_vaddr = entry->start; phdr->p_paddr = 0; phdr->p_filesz = phdr->p_memsz = entry->end - entry->start; phdr->p_align = PAGE_SIZE; phdr->p_flags = 0; if (entry->protection & VM_PROT_READ) phdr->p_flags |= PF_R; if (entry->protection & VM_PROT_WRITE) phdr->p_flags |= PF_W; if (entry->protection & VM_PROT_EXECUTE) phdr->p_flags |= PF_X; phc->offset += phdr->p_filesz; ++phc->phdr; return 0; } /* * A callback for each_writable_segment() to gather information about * the number of segments and their total size. */ static int cb_size_segment(vm_map_entry_t entry, void *closure) { struct sseg_closure *ssc = closure; ++ssc->count; ssc->vsize += entry->end - entry->start; return 0; } /* * A callback for each_segment() to gather information about * the number of text segments. */ static int cb_fpcount_segment(vm_map_entry_t entry, void *closure) { int *count = closure; struct vnode *vp; if (entry->object.vm_object->type == OBJT_VNODE) { vp = (struct vnode *)entry->object.vm_object->handle; if ((vp->v_flag & VCKPT) && curproc->p_textvp == vp) return 0; ++*count; } return 0; } static int cb_put_fp(vm_map_entry_t entry, void *closure) { struct fp_closure *fpc = closure; struct vn_hdr *vnh = fpc->vnh; Elf_Phdr *phdr = &vnh->vnh_phdr; struct vnode *vp; int error; /* * If an entry represents a vnode then write out a file handle. * * If we are checkpointing a checkpoint-restored program we do * NOT record the filehandle for the old checkpoint vnode (which * is mapped all over the place). Instead we rely on the fact * that a checkpoint-restored program does not mmap() the checkpt * vnode NOCORE, so its contents will be written out to the * new checkpoint file. This is necessary because the 'old' * checkpoint file is typically destroyed when a new one is created * and thus cannot be used to restore the new checkpoint. * * Theoretically we could create a chain of checkpoint files and * operate the checkpointing operation kinda like an incremental * checkpoint, but a checkpoint restore would then likely wind up * referencing many prior checkpoint files and that is a bit over * the top for the purpose of the checkpoint API. */ if (entry->object.vm_object->type == OBJT_VNODE) { vp = (struct vnode *)entry->object.vm_object->handle; if ((vp->v_flag & VCKPT) && curproc->p_textvp == vp) return 0; if (vnh == fpc->vnh_max) return EINVAL; if (vp->v_mount) vnh->vnh_fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid; error = VFS_VPTOFH(vp, &vnh->vnh_fh.fh_fid); if (error) { char *freepath, *fullpath; if (vn_fullpath(curproc, vp, &fullpath, &freepath)) { kprintf("Warning: coredump, error %d: cannot store file handle for vnode %p\n", error, vp); } else { kprintf("Warning: coredump, error %d: cannot store file handle for %s\n", error, fullpath); kfree(freepath, M_TEMP); } error = 0; } phdr->p_type = PT_LOAD; phdr->p_offset = 0; /* not written to core */ phdr->p_vaddr = entry->start; phdr->p_paddr = 0; phdr->p_filesz = phdr->p_memsz = entry->end - entry->start; phdr->p_align = PAGE_SIZE; phdr->p_flags = 0; if (entry->protection & VM_PROT_READ) phdr->p_flags |= PF_R; if (entry->protection & VM_PROT_WRITE) phdr->p_flags |= PF_W; if (entry->protection & VM_PROT_EXECUTE) phdr->p_flags |= PF_X; ++fpc->vnh; ++fpc->count; } return 0; } /* * For each writable segment in the process's memory map, call the given * function with a pointer to the map entry and some arbitrary * caller-supplied data. */ static int each_segment(struct proc *p, segment_callback func, void *closure, int writable) { int error = 0; vm_map_t map = &p->p_vmspace->vm_map; vm_map_entry_t entry; for (entry = map->header.next; error == 0 && entry != &map->header; entry = entry->next) { vm_object_t obj; /* * Don't dump inaccessible mappings, deal with legacy * coredump mode. * * Note that read-only segments related to the elf binary * are marked MAP_ENTRY_NOCOREDUMP now so we no longer * need to arbitrarily ignore such segments. */ if (elf_legacy_coredump) { if (writable && (entry->protection & VM_PROT_RW) != VM_PROT_RW) continue; } else { if (writable && (entry->protection & VM_PROT_ALL) == 0) continue; } /* * Dont include memory segment in the coredump if * MAP_NOCORE is set in mmap(2) or MADV_NOCORE in * madvise(2). * * Currently we only dump normal VM object maps. We do * not dump submaps or virtual page tables. */ if (writable && (entry->eflags & MAP_ENTRY_NOCOREDUMP)) continue; if (entry->maptype != VM_MAPTYPE_NORMAL) continue; if ((obj = entry->object.vm_object) == NULL) continue; /* Find the deepest backing object. */ while (obj->backing_object != NULL) obj = obj->backing_object; /* Ignore memory-mapped devices and such things. */ if (obj->type != OBJT_DEFAULT && obj->type != OBJT_SWAP && obj->type != OBJT_VNODE) continue; error = (*func)(entry, closure); } return error; } static void * target_reserve(elf_buf_t target, size_t bytes, int *error) { void *res = NULL; if (target->buf) { if (target->off + bytes > target->off_max) *error = EINVAL; else res = target->buf + target->off; } target->off += bytes; return (res); } /* * Write the core file header to the file, including padding up to * the page boundary. */ static int elf_corehdr(struct lwp *lp, int sig, struct file *fp, struct ucred *cred, int numsegs, elf_buf_t target) { int error; ssize_t nbytes; /* * Fill in the header. The fp is passed so we can detect and flag * a checkpoint file pointer within the core file itself, because * it may not be restored from the same file handle. */ error = elf_puthdr(lp, target, sig, WRITE, numsegs, fp); /* Write it to the core file. */ if (error == 0) { error = fp_write(fp, target->buf, target->off, &nbytes, UIO_SYSSPACE); } return error; } static int elf_puthdr(struct lwp *lp, elf_buf_t target, int sig, enum putmode mode, int numsegs, struct file *fp) { struct proc *p = lp->lwp_proc; int error = 0; size_t phoff; size_t noteoff; size_t notesz; Elf_Ehdr *ehdr; Elf_Phdr *phdr; ehdr = target_reserve(target, sizeof(Elf_Ehdr), &error); phoff = target->off; phdr = target_reserve(target, (numsegs + 1) * sizeof(Elf_Phdr), &error); noteoff = target->off; if (error == 0) elf_putallnotes(lp, target, sig, mode); notesz = target->off - noteoff; /* * put extra cruft for dumping process state here * - we really want it be before all the program * mappings * - we just need to update the offset accordingly * and GDB will be none the wiser. */ if (error == 0) error = elf_puttextvp(p, target); if (error == 0) error = elf_putsigs(lp, target); if (error == 0) error = elf_putfiles(p, target, fp); /* * Align up to a page boundary for the program segments. The * actual data will be written to the outptu file, not to elf_buf_t, * so we do not have to do any further bounds checking. */ target->off = round_page(target->off); if (error == 0 && ehdr != NULL) { /* * Fill in the ELF header. */ ehdr->e_ident[EI_MAG0] = ELFMAG0; ehdr->e_ident[EI_MAG1] = ELFMAG1; ehdr->e_ident[EI_MAG2] = ELFMAG2; ehdr->e_ident[EI_MAG3] = ELFMAG3; ehdr->e_ident[EI_CLASS] = ELF_CLASS; ehdr->e_ident[EI_DATA] = ELF_DATA; ehdr->e_ident[EI_VERSION] = EV_CURRENT; ehdr->e_ident[EI_OSABI] = ELFOSABI_FREEBSD; ehdr->e_ident[EI_ABIVERSION] = 0; ehdr->e_ident[EI_PAD] = 0; ehdr->e_type = ET_CORE; ehdr->e_machine = ELF_ARCH; ehdr->e_version = EV_CURRENT; ehdr->e_entry = 0; ehdr->e_phoff = phoff; ehdr->e_flags = 0; ehdr->e_ehsize = sizeof(Elf_Ehdr); ehdr->e_phentsize = sizeof(Elf_Phdr); ehdr->e_phnum = numsegs + 1; ehdr->e_shentsize = sizeof(Elf_Shdr); ehdr->e_shnum = 0; ehdr->e_shstrndx = SHN_UNDEF; } if (error == 0 && phdr != NULL) { /* * Fill in the program header entries. */ struct phdr_closure phc; /* The note segement. */ phdr->p_type = PT_NOTE; phdr->p_offset = noteoff; phdr->p_vaddr = 0; phdr->p_paddr = 0; phdr->p_filesz = notesz; phdr->p_memsz = 0; phdr->p_flags = 0; phdr->p_align = 0; ++phdr; /* All the writable segments from the program. */ phc.phdr = phdr; phc.phdr_max = phdr + numsegs; phc.offset = target->off; each_segment(p, cb_put_phdr, &phc, 1); } return (error); } /* * Append core dump notes to target ELF buffer or simply update target size * if dryrun selected. */ static int elf_putallnotes(struct lwp *corelp, elf_buf_t target, int sig, enum putmode mode) { struct proc *p = corelp->lwp_proc; int error; struct { prstatus_t status; prfpregset_t fpregs; prpsinfo_t psinfo; } *tmpdata; prstatus_t *status; prfpregset_t *fpregs; prpsinfo_t *psinfo; struct lwp *lp; /* * Allocate temporary storage for notes on heap to avoid stack overflow. */ if (mode != DRYRUN) { tmpdata = kmalloc(sizeof(*tmpdata), M_TEMP, M_ZERO | M_WAITOK); status = &tmpdata->status; fpregs = &tmpdata->fpregs; psinfo = &tmpdata->psinfo; } else { tmpdata = NULL; status = NULL; fpregs = NULL; psinfo = NULL; } /* * Append LWP-agnostic note. */ if (mode != DRYRUN) { psinfo->pr_version = PRPSINFO_VERSION; psinfo->pr_psinfosz = sizeof(prpsinfo_t); strncpy(psinfo->pr_fname, p->p_comm, sizeof(psinfo->pr_fname) - 1); /* * XXX - We don't fill in the command line arguments * properly yet. */ strncpy(psinfo->pr_psargs, p->p_comm, PRARGSZ); } error = elf_putnote(target, "FreeBSD", NT_PRPSINFO, psinfo, sizeof *psinfo); if (error) goto exit; /* * Append first note for LWP that triggered core so that it is * the selected one when the debugger starts. */ if (mode != DRYRUN) { status->pr_version = PRSTATUS_VERSION; status->pr_statussz = sizeof(prstatus_t); status->pr_gregsetsz = sizeof(gregset_t); status->pr_fpregsetsz = sizeof(fpregset_t); status->pr_osreldate = osreldate; status->pr_cursig = sig; /* * XXX GDB needs unique pr_pid for each LWP and does not * not support pr_pid==0 but lwp_tid can be 0, so hack unique * value. */ status->pr_pid = p->p_pid + corelp->lwp_tid; fill_regs(corelp, &status->pr_reg); fill_fpregs(corelp, fpregs); } error = elf_putnote(target, "FreeBSD", NT_PRSTATUS, status, sizeof *status); if (error) goto exit; error = elf_putnote(target, "FreeBSD", NT_FPREGSET, fpregs, sizeof *fpregs); if (error) goto exit; /* * Then append notes for other LWPs. */ FOREACH_LWP_IN_PROC(lp, p) { if (lp == corelp) continue; /* skip lwps being created */ if (lp->lwp_thread == NULL) continue; if (mode != DRYRUN) { status->pr_pid = p->p_pid + lp->lwp_tid; fill_regs(lp, &status->pr_reg); fill_fpregs(lp, fpregs); } error = elf_putnote(target, "FreeBSD", NT_PRSTATUS, status, sizeof *status); if (error) goto exit; error = elf_putnote(target, "FreeBSD", NT_FPREGSET, fpregs, sizeof *fpregs); if (error) goto exit; } exit: if (tmpdata != NULL) kfree(tmpdata, M_TEMP); return (error); } /* * Generate a note sub-structure. * * NOTE: 4-byte alignment. */ static int elf_putnote(elf_buf_t target, const char *name, int type, const void *desc, size_t descsz) { int error = 0; char *dst; Elf_Note note; note.n_namesz = strlen(name) + 1; note.n_descsz = descsz; note.n_type = type; dst = target_reserve(target, sizeof(note), &error); if (dst != NULL) bcopy(¬e, dst, sizeof note); dst = target_reserve(target, note.n_namesz, &error); if (dst != NULL) bcopy(name, dst, note.n_namesz); target->off = roundup2(target->off, sizeof(Elf_Word)); dst = target_reserve(target, note.n_descsz, &error); if (dst != NULL) bcopy(desc, dst, note.n_descsz); target->off = roundup2(target->off, sizeof(Elf_Word)); return(error); } static int elf_putsigs(struct lwp *lp, elf_buf_t target) { /* XXX lwp handle more than one lwp */ struct proc *p = lp->lwp_proc; int error = 0; struct ckpt_siginfo *csi; csi = target_reserve(target, sizeof(struct ckpt_siginfo), &error); if (csi) { csi->csi_ckptpisz = sizeof(struct ckpt_siginfo); bcopy(p->p_sigacts, &csi->csi_sigacts, sizeof(*p->p_sigacts)); bcopy(&p->p_realtimer, &csi->csi_itimerval, sizeof(struct itimerval)); bcopy(&lp->lwp_sigmask, &csi->csi_sigmask, sizeof(sigset_t)); csi->csi_sigparent = p->p_sigparent; } return(error); } static int elf_putfiles(struct proc *p, elf_buf_t target, struct file *ckfp) { int error = 0; int i; struct ckpt_filehdr *cfh = NULL; struct ckpt_fileinfo *cfi; struct file *fp; struct vnode *vp; /* * the duplicated loop is gross, but it was the only way * to eliminate uninitialized variable warnings */ cfh = target_reserve(target, sizeof(struct ckpt_filehdr), &error); if (cfh) { cfh->cfh_nfiles = 0; } /* * ignore STDIN/STDERR/STDOUT. */ for (i = 3; error == 0 && i < p->p_fd->fd_nfiles; i++) { fp = holdfp(p->p_fd, i, -1); if (fp == NULL) continue; /* * XXX Only checkpoint vnodes for now. */ if (fp->f_type != DTYPE_VNODE) { fdrop(fp); continue; } cfi = target_reserve(target, sizeof(struct ckpt_fileinfo), &error); if (cfi == NULL) { fdrop(fp); continue; } cfi->cfi_index = -1; cfi->cfi_type = fp->f_type; cfi->cfi_flags = fp->f_flag; cfi->cfi_offset = fp->f_offset; cfi->cfi_ckflags = 0; if (fp == ckfp) cfi->cfi_ckflags |= CKFIF_ISCKPTFD; /* f_count and f_msgcount should not be saved/restored */ /* XXX save cred info */ switch(fp->f_type) { case DTYPE_VNODE: vp = (struct vnode *)fp->f_data; /* * it looks like a bug in ptrace is marking * a non-vnode as a vnode - until we find the * root cause this will at least prevent * further panics from truss */ if (vp == NULL || vp->v_mount == NULL) break; cfh->cfh_nfiles++; cfi->cfi_index = i; cfi->cfi_fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid; error = VFS_VPTOFH(vp, &cfi->cfi_fh.fh_fid); break; default: break; } fdrop(fp); } return(error); } static int elf_puttextvp(struct proc *p, elf_buf_t target) { int error = 0; int *vn_count; struct fp_closure fpc; struct ckpt_vminfo *vminfo; vminfo = target_reserve(target, sizeof(struct ckpt_vminfo), &error); if (vminfo != NULL) { vminfo->cvm_dsize = p->p_vmspace->vm_dsize; vminfo->cvm_tsize = p->p_vmspace->vm_tsize; vminfo->cvm_daddr = p->p_vmspace->vm_daddr; vminfo->cvm_taddr = p->p_vmspace->vm_taddr; } fpc.count = 0; vn_count = target_reserve(target, sizeof(int), &error); if (target->buf != NULL) { fpc.vnh = (struct vn_hdr *)(target->buf + target->off); fpc.vnh_max = fpc.vnh + (target->off_max - target->off) / sizeof(struct vn_hdr); error = each_segment(p, cb_put_fp, &fpc, 0); if (vn_count) *vn_count = fpc.count; } else { error = each_segment(p, cb_fpcount_segment, &fpc.count, 0); } target->off += fpc.count * sizeof(struct vn_hdr); return(error); } /* * Tell kern_execve.c about it, with a little help from the linker. */ static struct execsw elf_execsw = {exec_elf_imgact, "ELF"}; EXEC_SET_ORDERED(elf, elf_execsw, SI_ORDER_FIRST);