diff options
Diffstat (limited to 'sys/kern/imgact_elf.c')
| -rw-r--r-- | sys/kern/imgact_elf.c | 1075 |
1 files changed, 1075 insertions, 0 deletions
diff --git a/sys/kern/imgact_elf.c b/sys/kern/imgact_elf.c new file mode 100644 index 0000000..9044527 --- /dev/null +++ b/sys/kern/imgact_elf.c @@ -0,0 +1,1075 @@ +/*- + * Copyright (c) 2000 David O'Brien + * 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 without 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. + * + * $FreeBSD$ + */ + +#include <sys/param.h> +#include <sys/exec.h> +#include <sys/fcntl.h> +#include <sys/imgact.h> +#include <sys/imgact_elf.h> +#include <sys/kernel.h> +#include <sys/lock.h> +#include <sys/malloc.h> +#include <sys/mutex.h> +#include <sys/mman.h> +#include <sys/namei.h> +#include <sys/pioctl.h> +#include <sys/proc.h> +#include <sys/procfs.h> +#include <sys/resourcevar.h> +#include <sys/systm.h> +#include <sys/signalvar.h> +#include <sys/stat.h> +#include <sys/sx.h> +#include <sys/syscall.h> +#include <sys/sysctl.h> +#include <sys/sysent.h> +#include <sys/vnode.h> + +#include <vm/vm.h> +#include <vm/vm_kern.h> +#include <vm/vm_param.h> +#include <vm/pmap.h> +#include <vm/vm_map.h> +#include <vm/vm_object.h> +#include <vm/vm_extern.h> + +#include <machine/elf.h> +#include <machine/md_var.h> + +#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, ""); + +struct sysentvec elf_freebsd_sysvec = { + SYS_MAXSYSCALL, + sysent, + 0, + 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", + "", + "/usr/libexec/ld-elf.so.1", + &elf_freebsd_sysvec + }; +static Elf_Brandinfo *elf_brand_list[MAX_BRANDS] = { + &freebsd_brand_info, + NULL, NULL, NULL, + NULL, NULL, NULL, NULL + }; + +int +elf_insert_brand_entry(Elf_Brandinfo *entry) +{ + int i; + + for (i=1; i<MAX_BRANDS; i++) { + if (elf_brand_list[i] == NULL) { + elf_brand_list[i] = entry; + break; + } + } + if (i == MAX_BRANDS) + return -1; + return 0; +} + +int +elf_remove_brand_entry(Elf_Brandinfo *entry) +{ + int i; + + for (i=1; i<MAX_BRANDS; i++) { + if (elf_brand_list[i] == entry) { + elf_brand_list[i] = NULL; + break; + } + } + if (i == MAX_BRANDS) + return -1; + return 0; +} + +int +elf_brand_inuse(Elf_Brandinfo *entry) +{ + struct proc *p; + int rval = FALSE; + + sx_slock(&allproc_lock); + LIST_FOREACH(p, &allproc, p_list) { + if (p->p_sysent == entry->sysvec) { + rval = TRUE; + break; + } + } + sx_sunlock(&allproc_lock); + + return (rval); +} + +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) + return ENOEXEC; + + if (!ELF_MACHINE_OK(hdr->e_machine)) + return ENOEXEC; + + if (hdr->e_version != ELF_TARG_VER) + 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; + size_t copy_len; + vm_object_t object; + vm_offset_t file_addr; + vm_offset_t data_buf = 0; + + GIANT_REQUIRED; + + VOP_GETVOBJECT(vp, &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 > object->un_pager.vnp.vnp_size || + 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); + vm_map_lock(&vmspace->vm_map); + rv = vm_map_insert(&vmspace->vm_map, + object, + file_addr, /* file offset */ + map_addr, /* virtual start */ + map_addr + map_len,/* virtual end */ + prot, + VM_PROT_ALL, + MAP_COPY_ON_WRITE | MAP_PREFAULT); + vm_map_unlock(&vmspace->vm_map); + 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) { + vm_map_lock(&vmspace->vm_map); + rv = vm_map_insert(&vmspace->vm_map, NULL, 0, + map_addr, map_addr + map_len, + VM_PROT_ALL, VM_PROT_ALL, 0); + vm_map_unlock(&vmspace->vm_map); + if (rv != KERN_SUCCESS) { + return EINVAL; + } + } + + if (copy_len != 0) { + vm_object_reference(object); + rv = vm_map_find(exec_map, + object, + trunc_page(offset + filsz), + &data_buf, + PAGE_SIZE, + TRUE, + VM_PROT_READ, + VM_PROT_ALL, + MAP_COPY_ON_WRITE | MAP_PREFAULT_PARTIAL); + if (rv != KERN_SUCCESS) { + vm_object_deallocate(object); + return EINVAL; + } + + /* send the page fragment to user space */ + error = copyout((caddr_t)data_buf, (caddr_t)map_addr, copy_len); + vm_map_remove(exec_map, data_buf, data_buf + PAGE_SIZE); + 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 nameidata nd; + struct vattr attr; + struct image_params image_params; + } *tempdata; + const Elf_Ehdr *hdr = NULL; + const Elf_Phdr *phdr = NULL; + struct nameidata *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; + + if (curthread->td_proc != p) + panic("elf_load_file - thread"); /* XXXKSE DIAGNOSTIC */ + + tempdata = malloc(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->uap = NULL; + imgp->attr = attr; + imgp->firstpage = NULL; + imgp->image_header = (char *)kmem_alloc_wait(exec_map, PAGE_SIZE); + + if (imgp->image_header == NULL) { + nd->ni_vp = NULL; + error = ENOMEM; + goto fail; + } + + /* XXXKSE */ + NDINIT(nd, LOOKUP, LOCKLEAF|FOLLOW, UIO_SYSSPACE, file, curthread); + + if ((error = namei(nd)) != 0) { + nd->ni_vp = NULL; + goto fail; + } + NDFREE(nd, NDF_ONLY_PNBUF); + imgp->vp = nd->ni_vp; + + /* + * Check permissions, modes, uid, etc on the file, and "open" it. + */ + error = exec_check_permissions(imgp); + if (error) { + VOP_UNLOCK(nd->ni_vp, 0, curthread); /* XXXKSE */ + 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) + nd->ni_vp->v_flag |= VTEXT; + VOP_UNLOCK(nd->ni_vp, 0, curthread); /* XXXKSE */ + 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 */ + if ((hdr->e_phoff > PAGE_SIZE) || + (hdr->e_phoff + hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE) { + 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; + + if ((error = elf_load_section(p, vmspace, nd->ni_vp, + phdr[i].p_offset, + (caddr_t)phdr[i].p_vaddr + + rbase, + phdr[i].p_memsz, + phdr[i].p_filesz, prot)) != 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->image_header) + kmem_free_wakeup(exec_map, (vm_offset_t)imgp->image_header, + PAGE_SIZE); + if (nd->ni_vp) + vrele(nd->ni_vp); + + free(tempdata, M_TEMP); + + return error; +} + +/* + * non static, as it can be overridden by start_init() + */ +#ifdef __ia64__ +int fallback_elf_brand = ELFOSABI_FREEBSD; +#else +int fallback_elf_brand = -1; +#endif +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; + u_long text_addr = 0, data_addr = 0; + u_long addr, entry = 0, proghdr = 0; + int error, i; + const char *interp = NULL; + Elf_Brandinfo *brand_info; + char *path; + + GIANT_REQUIRED; + + /* + * 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. + */ + + /* + * 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. + */ + mtx_lock(&imgp->vp->v_interlock); + imgp->vp->v_flag |= VTEXT; + mtx_unlock(&imgp->vp->v_interlock); + + if ((error = exec_extract_strings(imgp)) != 0) + goto fail; + + exec_new_vmspace(imgp); + + 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; + + /* + * Is this .text or .data ?? + * + * We only handle one each of those yet XXX + */ + if (hdr->e_entry >= phdr[i].p_vaddr && + hdr->e_entry <(phdr[i].p_vaddr+phdr[i].p_memsz)) { + text_addr = trunc_page(phdr[i].p_vaddr); + text_size = round_page(phdr[i].p_memsz + + phdr[i].p_vaddr - + text_addr); + entry = (u_long)hdr->e_entry; + } else { + data_addr = trunc_page(phdr[i].p_vaddr); + data_size = round_page(phdr[i].p_memsz + + phdr[i].p_vaddr - + data_addr); + } + 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_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) { + 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; + } + } + } + + /* Lacking a known brand, 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 = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); + snprintf(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); + free(path, M_TEMP); + goto fail; + } + } + free(path, M_TEMP); + } + + /* + * Construct auxargs table (used by the fixup routine) + */ + elf_auxargs = malloc(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->argc + imgp->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); + + free(imgp->auxargs, M_TEMP); + imgp->auxargs = NULL; + + (*stack_base)--; + suword(*stack_base, (long) imgp->argc); + return 0; +} + +/* + * Code for generating ELF core dumps. + */ + +typedef void (*segment_callback)(vm_map_entry_t, void *); + +/* Closure for cb_put_phdr(). */ +struct phdr_closure { + Elf_Phdr *phdr; /* Program header to fill in */ + 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 size; /* Total size of all writable segments. */ +}; + +static void cb_put_phdr(vm_map_entry_t, void *); +static void cb_size_segment(vm_map_entry_t, void *); +static void each_writable_segment(struct proc *, segment_callback, void *); +static int elf_corehdr(struct thread *, struct vnode *, struct ucred *, + int, void *, size_t); +static void elf_puthdr(struct proc *, void *, size_t *, + const prstatus_t *, const prfpregset_t *, const prpsinfo_t *, int); +static void elf_putnote(void *, size_t *, const char *, int, + const void *, size_t); + +extern int osreldate; + +int +elf_coredump(td, vp, limit) + struct thread *td; + register struct vnode *vp; + off_t limit; +{ + register struct proc *p = td->td_proc; + register struct ucred *cred = td->td_ucred; + int error = 0; + struct sseg_closure seginfo; + void *hdr; + size_t hdrsize; + + /* Size the program segments. */ + seginfo.count = 0; + seginfo.size = 0; + each_writable_segment(p, cb_size_segment, &seginfo); + + /* + * 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. + */ + hdrsize = 0; + elf_puthdr((struct proc *)NULL, (void *)NULL, &hdrsize, + (const prstatus_t *)NULL, (const prfpregset_t *)NULL, + (const prpsinfo_t *)NULL, seginfo.count); + + if (hdrsize + seginfo.size >= limit) + return (EFAULT); + + /* + * Allocate memory for building the header, fill it up, + * and write it out. + */ + hdr = malloc(hdrsize, M_TEMP, M_WAITOK); + if (hdr == NULL) { + return EINVAL; + } + error = elf_corehdr(td, vp, cred, seginfo.count, hdr, hdrsize); + + /* Write the contents of all of the writable segments. */ + if (error == 0) { + Elf_Phdr *php; + off_t offset; + int i; + + php = (Elf_Phdr *)((char *)hdr + sizeof(Elf_Ehdr)) + 1; + offset = hdrsize; + for (i = 0; i < seginfo.count; i++) { + error = vn_rdwr_inchunks(UIO_WRITE, vp, + (caddr_t)php->p_vaddr, + php->p_filesz, offset, UIO_USERSPACE, + IO_UNIT | IO_DIRECT, cred, (int *)NULL, curthread); /* XXXKSE */ + if (error != 0) + break; + offset += php->p_filesz; + php++; + } + } + free(hdr, M_TEMP); + + return error; +} + +/* + * A callback for each_writable_segment() to write out the segment's + * program header entry. + */ +static void +cb_put_phdr(entry, closure) + vm_map_entry_t entry; + void *closure; +{ + struct phdr_closure *phc = (struct phdr_closure *)closure; + Elf_Phdr *phdr = phc->phdr; + + 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++; +} + +/* + * A callback for each_writable_segment() to gather information about + * the number of segments and their total size. + */ +static void +cb_size_segment(entry, closure) + vm_map_entry_t entry; + void *closure; +{ + struct sseg_closure *ssc = (struct sseg_closure *)closure; + + ssc->count++; + ssc->size += entry->end - entry->start; +} + +/* + * 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 void +each_writable_segment(p, func, closure) + struct proc *p; + segment_callback func; + void *closure; +{ + vm_map_t map = &p->p_vmspace->vm_map; + vm_map_entry_t entry; + + for (entry = map->header.next; entry != &map->header; + entry = entry->next) { + vm_object_t obj; + + if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) || + (entry->protection & (VM_PROT_READ|VM_PROT_WRITE)) != + (VM_PROT_READ|VM_PROT_WRITE)) + continue; + + /* + ** Dont include memory segment in the coredump if + ** MAP_NOCORE is set in mmap(2) or MADV_NOCORE in + ** madvise(2). + */ + if (entry->eflags & MAP_ENTRY_NOCOREDUMP) + 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; + + (*func)(entry, closure); + } +} + +/* + * Write the core file header to the file, including padding up to + * the page boundary. + */ +static int +elf_corehdr(td, vp, cred, numsegs, hdr, hdrsize) + struct thread *td; + struct vnode *vp; + struct ucred *cred; + int numsegs; + size_t hdrsize; + void *hdr; +{ + struct { + prstatus_t status; + prfpregset_t fpregset; + prpsinfo_t psinfo; + } *tempdata; + struct proc *p = td->td_proc; + size_t off; + prstatus_t *status; + prfpregset_t *fpregset; + prpsinfo_t *psinfo; + + tempdata = malloc(sizeof(*tempdata), M_TEMP, M_ZERO | M_WAITOK); + status = &tempdata->status; + fpregset = &tempdata->fpregset; + psinfo = &tempdata->psinfo; + + /* Gather the information for the header. */ + 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 = p->p_sig; + status->pr_pid = p->p_pid; + fill_regs(td, &status->pr_reg); + + fill_fpregs(td, fpregset); + + 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); + + /* Fill in the header. */ + bzero(hdr, hdrsize); + off = 0; + elf_puthdr(p, hdr, &off, status, fpregset, psinfo, numsegs); + + free(tempdata, M_TEMP); + + /* Write it to the core file. */ + return vn_rdwr_inchunks(UIO_WRITE, vp, hdr, hdrsize, (off_t)0, + UIO_SYSSPACE, IO_UNIT | IO_DIRECT, cred, NULL, td); /* XXXKSE */ +} + +static void +elf_puthdr(struct proc *p, void *dst, size_t *off, const prstatus_t *status, + const prfpregset_t *fpregset, const prpsinfo_t *psinfo, int numsegs) +{ + size_t ehoff; + size_t phoff; + size_t noteoff; + size_t notesz; + + ehoff = *off; + *off += sizeof(Elf_Ehdr); + + phoff = *off; + *off += (numsegs + 1) * sizeof(Elf_Phdr); + + noteoff = *off; + elf_putnote(dst, off, "FreeBSD", NT_PRSTATUS, status, + sizeof *status); + elf_putnote(dst, off, "FreeBSD", NT_FPREGSET, fpregset, + sizeof *fpregset); + elf_putnote(dst, off, "FreeBSD", NT_PRPSINFO, psinfo, + sizeof *psinfo); + notesz = *off - noteoff; + + /* Align up to a page boundary for the program segments. */ + *off = round_page(*off); + + if (dst != NULL) { + Elf_Ehdr *ehdr; + Elf_Phdr *phdr; + struct phdr_closure phc; + + /* + * Fill in the ELF header. + */ + ehdr = (Elf_Ehdr *)((char *)dst + ehoff); + 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; + + /* + * Fill in the program header entries. + */ + phdr = (Elf_Phdr *)((char *)dst + phoff); + + /* 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.offset = *off; + each_writable_segment(p, cb_put_phdr, &phc); + } +} + +static void +elf_putnote(void *dst, size_t *off, const char *name, int type, + const void *desc, size_t descsz) +{ + Elf_Note note; + + note.n_namesz = strlen(name) + 1; + note.n_descsz = descsz; + note.n_type = type; + if (dst != NULL) + bcopy(¬e, (char *)dst + *off, sizeof note); + *off += sizeof note; + if (dst != NULL) + bcopy(name, (char *)dst + *off, note.n_namesz); + *off += roundup2(note.n_namesz, sizeof(Elf_Size)); + if (dst != NULL) + bcopy(desc, (char *)dst + *off, note.n_descsz); + *off += roundup2(note.n_descsz, sizeof(Elf_Size)); +} + +/* + * Tell kern_execve.c about it, with a little help from the linker. + */ +static struct execsw elf_execsw = {exec_elf_imgact, "ELF"}; +EXEC_SET(elf, elf_execsw); |
