示例#1
0
/*
 * Actual dumper
 *
 * This is a two-pass process; first we find the offsets of the bits,
 * and then they are actually written out.  If we run out of core limit
 * we just truncate.
 */
static int elf_core_dump(long signr, struct pt_regs * regs, struct file * file)
{
	int has_dumped = 0;
	mm_segment_t fs;
	int segs;
	size_t size = 0;
	int i;
	struct vm_area_struct *vma;
	struct elfhdr elf;
	off_t offset = 0, dataoff;
	unsigned long limit = current->rlim[RLIMIT_CORE].rlim_cur;
	int numnote = 4;
	struct memelfnote notes[4];
	struct elf_prstatus prstatus;	/* NT_PRSTATUS */
	elf_fpregset_t fpu;		/* NT_PRFPREG */
	struct elf_prpsinfo psinfo;	/* NT_PRPSINFO */

	/* first copy the parameters from user space */
	memset(&psinfo, 0, sizeof(psinfo));
	{
		unsigned int i, len;

		len = current->mm->arg_end - current->mm->arg_start;
		if (len >= ELF_PRARGSZ)
			len = ELF_PRARGSZ-1;
		copy_from_user(&psinfo.pr_psargs,
			      (const char *)current->mm->arg_start, len);
		for(i = 0; i < len; i++)
			if (psinfo.pr_psargs[i] == 0)
				psinfo.pr_psargs[i] = ' ';
		psinfo.pr_psargs[len] = 0;

	}

	memset(&prstatus, 0, sizeof(prstatus));
	/*
	 * This transfers the registers from regs into the standard
	 * coredump arrangement, whatever that is.
	 */
#ifdef ELF_CORE_COPY_REGS
	ELF_CORE_COPY_REGS(prstatus.pr_reg, regs)
#else
	if (sizeof(elf_gregset_t) != sizeof(struct pt_regs))
	{
		printk("sizeof(elf_gregset_t) (%ld) != sizeof(struct pt_regs) (%ld)\n",
			(long)sizeof(elf_gregset_t), (long)sizeof(struct pt_regs));
	}
	else
		*(struct pt_regs *)&prstatus.pr_reg = *regs;
#endif

	/* now stop all vm operations */
	down_write(&current->mm->mmap_sem);
	segs = current->mm->map_count;

#ifdef DEBUG
	printk("elf_core_dump: %d segs %lu limit\n", segs, limit);
#endif

	/* Set up header */
	memcpy(elf.e_ident, ELFMAG, SELFMAG);
	elf.e_ident[EI_CLASS] = ELF_CLASS;
	elf.e_ident[EI_DATA] = ELF_DATA;
	elf.e_ident[EI_VERSION] = EV_CURRENT;
	memset(elf.e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);

	elf.e_type = ET_CORE;
	elf.e_machine = ELF_ARCH;
	elf.e_version = EV_CURRENT;
	elf.e_entry = 0;
	elf.e_phoff = sizeof(elf);
	elf.e_shoff = 0;
#ifdef ELF_CORE_EFLAGS
	elf.e_flags = ELF_CORE_EFLAGS;
#else
	elf.e_flags = 0;
#endif
	elf.e_ehsize = sizeof(elf);
	elf.e_phentsize = sizeof(struct elf_phdr);
	elf.e_phnum = segs+1;		/* Include notes */
	elf.e_shentsize = 0;
	elf.e_shnum = 0;
	elf.e_shstrndx = 0;

	fs = get_fs();
	set_fs(KERNEL_DS);

	has_dumped = 1;
	current->flags |= PF_DUMPCORE;

	DUMP_WRITE(&elf, sizeof(elf));
	offset += sizeof(elf);				/* Elf header */
	offset += (segs+1) * sizeof(struct elf_phdr);	/* Program headers */

	/*
	 * Set up the notes in similar form to SVR4 core dumps made
	 * with info from their /proc.
	 */

	notes[0].name = "CORE";
	notes[0].type = NT_PRSTATUS;
	notes[0].datasz = sizeof(prstatus);
	notes[0].data = &prstatus;
	prstatus.pr_info.si_signo = prstatus.pr_cursig = signr;
	prstatus.pr_sigpend = current->pending.signal.sig[0];
	prstatus.pr_sighold = current->blocked.sig[0];
	psinfo.pr_pid = prstatus.pr_pid = current->pid;
	psinfo.pr_ppid = prstatus.pr_ppid = current->p_pptr->pid;
	psinfo.pr_pgrp = prstatus.pr_pgrp = current->pgrp;
	psinfo.pr_sid = prstatus.pr_sid = current->session;
	prstatus.pr_utime.tv_sec = CT_TO_SECS(current->times.tms_utime);
	prstatus.pr_utime.tv_usec = CT_TO_USECS(current->times.tms_utime);
	prstatus.pr_stime.tv_sec = CT_TO_SECS(current->times.tms_stime);
	prstatus.pr_stime.tv_usec = CT_TO_USECS(current->times.tms_stime);
	prstatus.pr_cutime.tv_sec = CT_TO_SECS(current->times.tms_cutime);
	prstatus.pr_cutime.tv_usec = CT_TO_USECS(current->times.tms_cutime);
	prstatus.pr_cstime.tv_sec = CT_TO_SECS(current->times.tms_cstime);
	prstatus.pr_cstime.tv_usec = CT_TO_USECS(current->times.tms_cstime);

#ifdef DEBUG
	dump_regs("Passed in regs", (elf_greg_t *)regs);
	dump_regs("prstatus regs", (elf_greg_t *)&prstatus.pr_reg);
#endif

	notes[1].name = "CORE";
	notes[1].type = NT_PRPSINFO;
	notes[1].datasz = sizeof(psinfo);
	notes[1].data = &psinfo;
	i = current->state ? ffz(~current->state) + 1 : 0;
	psinfo.pr_state = i;
	psinfo.pr_sname = (i < 0 || i > 5) ? '.' : "RSDZTD"[i];
	psinfo.pr_zomb = psinfo.pr_sname == 'Z';
	psinfo.pr_nice = task_nice(current);
	psinfo.pr_flag = current->flags;
	psinfo.pr_uid = NEW_TO_OLD_UID(current->uid);
	psinfo.pr_gid = NEW_TO_OLD_GID(current->gid);
	strncpy(psinfo.pr_fname, current->comm, sizeof(psinfo.pr_fname));

	notes[2].name = "CORE";
	notes[2].type = NT_TASKSTRUCT;
	notes[2].datasz = sizeof(*current);
	notes[2].data = current;

	/* Try to dump the FPU. */
	prstatus.pr_fpvalid = dump_fpu (regs, &fpu);
	if (!prstatus.pr_fpvalid)
	{
		numnote--;
	}
	else
	{
		notes[3].name = "CORE";
		notes[3].type = NT_PRFPREG;
		notes[3].datasz = sizeof(fpu);
		notes[3].data = &fpu;
	}
	
	/* Write notes phdr entry */
	{
		struct elf_phdr phdr;
		int sz = 0;

		for(i = 0; i < numnote; i++)
			sz += notesize(&notes[i]);

		phdr.p_type = PT_NOTE;
		phdr.p_offset = offset;
		phdr.p_vaddr = 0;
		phdr.p_paddr = 0;
		phdr.p_filesz = sz;
		phdr.p_memsz = 0;
		phdr.p_flags = 0;
		phdr.p_align = 0;

		offset += phdr.p_filesz;
		DUMP_WRITE(&phdr, sizeof(phdr));
	}

	/* Page-align dumped data */
	dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);

	/* Write program headers for segments dump */
	for(vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
		struct elf_phdr phdr;
		size_t sz;

		sz = vma->vm_end - vma->vm_start;

		phdr.p_type = PT_LOAD;
		phdr.p_offset = offset;
		phdr.p_vaddr = vma->vm_start;
		phdr.p_paddr = 0;
		phdr.p_filesz = maydump(vma) ? sz : 0;
		phdr.p_memsz = sz;
		offset += phdr.p_filesz;
		phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
		if (vma->vm_flags & VM_WRITE) phdr.p_flags |= PF_W;
		if (vma->vm_flags & VM_EXEC) phdr.p_flags |= PF_X;
		phdr.p_align = ELF_EXEC_PAGESIZE;

		DUMP_WRITE(&phdr, sizeof(phdr));
	}

	for(i = 0; i < numnote; i++)
		if (!writenote(&notes[i], file))
			goto end_coredump;

	DUMP_SEEK(dataoff);

	for(vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
		unsigned long addr;

		if (!maydump(vma))
			continue;

#ifdef DEBUG
		printk("elf_core_dump: writing %08lx-%08lx\n", vma->vm_start, vma->vm_end);
#endif

		for (addr = vma->vm_start;
		     addr < vma->vm_end;
		     addr += PAGE_SIZE) {
			struct page* page;
			struct vm_area_struct *vma;

			if (get_user_pages(current, current->mm, addr, 1, 0, 1,
						&page, &vma) <= 0) {
				DUMP_SEEK (file->f_pos + PAGE_SIZE);
			} else {
				if (page == ZERO_PAGE(addr)) {
					DUMP_SEEK (file->f_pos + PAGE_SIZE);
				} else {
					void *kaddr;
					flush_cache_page(vma, addr);
					kaddr = kmap(page);
					DUMP_WRITE(kaddr, PAGE_SIZE);
					flush_page_to_ram(page);
					kunmap(page);
				}
				put_page(page);
			}
		}
	}

	if ((off_t) file->f_pos != offset) {
		/* Sanity check */
		printk("elf_core_dump: file->f_pos (%ld) != offset (%ld)\n",
		       (off_t) file->f_pos, offset);
	}

 end_coredump:
	set_fs(fs);
	up_write(&current->mm->mmap_sem);
	return has_dumped;
}