irixelf.c

LINUX 2.6.17.4的源码

#ifdef DEBUG
	dump_phdrs(user_phdrp, cnt);
#endif

	for (i = 0; i < cnt; i++, hp++) {
		if (__get_user(type, &hp->p_type))
			return -EFAULT;
		if (type != PT_LOAD) {
			printk("irix_mapelf: One section is not PT_LOAD!\n");
			return -ENOEXEC;
		}
	}

	filp = fget(fd);
	if (!filp)
		return -EACCES;
	if(!filp->f_op) {
		printk("irix_mapelf: Bogon filp!\n");
		fput(filp);
		return -EACCES;
	}

	hp = user_phdrp;
	for(i = 0; i < cnt; i++, hp++) {
		int prot;

		retval = __get_user(vaddr, &hp->p_vaddr);
		retval |= __get_user(filesz, &hp->p_filesz);
		retval |= __get_user(offset, &hp->p_offset);
		retval |= __get_user(flags, &hp->p_flags);
		if (retval)
			return retval;

		prot  = (flags & PF_R) ? PROT_READ : 0;
		prot |= (flags & PF_W) ? PROT_WRITE : 0;
		prot |= (flags & PF_X) ? PROT_EXEC : 0;

		down_write(&current->mm->mmap_sem);
		retval = do_mmap(filp, (vaddr & 0xfffff000),
				 (filesz + (vaddr & 0xfff)),
				 prot, (MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE),
				 (offset & 0xfffff000));
		up_write(&current->mm->mmap_sem);

		if (retval != (vaddr & 0xfffff000)) {
			printk("irix_mapelf: do_mmap fails with %d!\n", retval);
			fput(filp);
			return retval;
		}
	}

	pr_debug("irix_mapelf: Success, returning %08lx\n",
		 (unsigned long) user_phdrp->p_vaddr);

	fput(filp);

	if (__get_user(vaddr, &user_phdrp->p_vaddr))
		return -EFAULT;

	return vaddr;
}

/*
 * ELF core dumper
 *
 * Modelled on fs/exec.c:aout_core_dump()
 * Jeremy Fitzhardinge <[e-mail]>
 */

/* These are the only things you should do on a core-file: use only these
 * functions to write out all the necessary info.
 */
static int dump_write(struct file *file, const void __user *addr, int nr)
{
	return file->f_op->write(file, (const char __user *) addr, nr, &file->f_pos) == nr;
}

static int dump_seek(struct file *file, off_t off)
{
	if (file->f_op->llseek) {
		if (file->f_op->llseek(file, off, 0) != off)
			return 0;
	} else
		file->f_pos = off;
	return 1;
}

/* Decide whether a segment is worth dumping; default is yes to be
 * sure (missing info is worse than too much; etc).
 * Personally I'd include everything, and use the coredump limit...
 *
 * I think we should skip something. But I am not sure how. H.J.
 */
static inline int maydump(struct vm_area_struct *vma)
{
	if (!(vma->vm_flags & (VM_READ|VM_WRITE|VM_EXEC)))
		return 0;
#if 1
	if (vma->vm_flags & (VM_WRITE|VM_GROWSUP|VM_GROWSDOWN))
		return 1;
	if (vma->vm_flags & (VM_READ|VM_EXEC|VM_EXECUTABLE|VM_SHARED))
		return 0;
#endif
	return 1;
}

#define roundup(x, y)  ((((x)+((y)-1))/(y))*(y))

/* An ELF note in memory. */
struct memelfnote
{
	const char *name;
	int type;
	unsigned int datasz;
	void *data;
};

static int notesize(struct memelfnote *en)
{
	int sz;

	sz = sizeof(struct elf_note);
	sz += roundup(strlen(en->name), 4);
	sz += roundup(en->datasz, 4);

	return sz;
}

/* #define DEBUG */

#define DUMP_WRITE(addr, nr)	\
	if (!dump_write(file, (addr), (nr))) \
		goto end_coredump;
#define DUMP_SEEK(off)	\
	if (!dump_seek(file, (off))) \
		goto end_coredump;

static int writenote(struct memelfnote *men, struct file *file)
{
	struct elf_note en;

	en.n_namesz = strlen(men->name);
	en.n_descsz = men->datasz;
	en.n_type = men->type;

	DUMP_WRITE(&en, sizeof(en));
	DUMP_WRITE(men->name, en.n_namesz);
	/* XXX - cast from long long to long to avoid need for libgcc.a */
	DUMP_SEEK(roundup((unsigned long)file->f_pos, 4));	/* XXX */
	DUMP_WRITE(men->data, men->datasz);
	DUMP_SEEK(roundup((unsigned long)file->f_pos, 4));	/* XXX */

	return 1;

end_coredump:
	return 0;
}
#undef DUMP_WRITE
#undef DUMP_SEEK

#define DUMP_WRITE(addr, nr)	\
	if (!dump_write(file, (addr), (nr))) \
		goto end_coredump;
#define DUMP_SEEK(off)	\
	if (!dump_seek(file, (off))) \
		goto end_coredump;

/* 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 irix_core_dump(long signr, struct pt_regs * regs, struct file *file)
{
	int has_dumped = 0;
	mm_segment_t fs;
	int segs;
	int i;
	size_t size;
	struct vm_area_struct *vma;
	struct elfhdr elf;
	off_t offset = 0, dataoff;
	int limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
	int numnote = 3;
	struct memelfnote notes[3];
	struct elf_prstatus prstatus;	/* NT_PRSTATUS */
	elf_fpregset_t fpu;		/* NT_PRFPREG */
	struct elf_prpsinfo psinfo;	/* NT_PRPSINFO */

	/* Count what's needed to dump, up to the limit of coredump size. */
	segs = 0;
	size = 0;
	for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
		if (maydump(vma))
		{
			int sz = vma->vm_end-vma->vm_start;

			if (size+sz >= limit)
				break;
			else
				size += sz;
		}

		segs++;
	}
#ifdef DEBUG
	printk("irix_core_dump: %d segs taking %d bytes\n", segs, size);
#endif

	/* Set up header. */
	memcpy(elf.e_ident, ELFMAG, SELFMAG);
	elf.e_ident[EI_CLASS] = ELFCLASS32;
	elf.e_ident[EI_DATA] = ELFDATA2LSB;
	elf.e_ident[EI_VERSION] = EV_CURRENT;
	elf.e_ident[EI_OSABI] = ELF_OSABI;
	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;
	elf.e_flags = 0;
	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.
	 */
	memset(&psinfo, 0, sizeof(psinfo));
	memset(&prstatus, 0, sizeof(prstatus));

	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->parent->pid;
	psinfo.pr_pgrp = prstatus.pr_pgrp = process_group(current);
	psinfo.pr_sid = prstatus.pr_sid = current->signal->session;
	if (current->pid == current->tgid) {
		/*
		 * This is the record for the group leader.  Add in the
		 * cumulative times of previous dead threads.  This total
		 * won't include the time of each live thread whose state
		 * is included in the core dump.  The final total reported
		 * to our parent process when it calls wait4 will include
		 * those sums as well as the little bit more time it takes
		 * this and each other thread to finish dying after the
		 * core dump synchronization phase.
		 */
		jiffies_to_timeval(current->utime + current->signal->utime,
		                   &prstatus.pr_utime);
		jiffies_to_timeval(current->stime + current->signal->stime,
		                   &prstatus.pr_stime);
	} else {
		jiffies_to_timeval(current->utime, &prstatus.pr_utime);
		jiffies_to_timeval(current->stime, &prstatus.pr_stime);
	}
	jiffies_to_timeval(current->signal->cutime, &prstatus.pr_cutime);
	jiffies_to_timeval(current->signal->cstime, &prstatus.pr_cstime);

	if (sizeof(elf_gregset_t) != sizeof(struct pt_regs)) {
		printk("sizeof(elf_gregset_t) (%d) != sizeof(struct pt_regs) "
		       "(%d)\n", sizeof(elf_gregset_t), sizeof(struct pt_regs));
	} else {
		*(struct pt_regs *)&prstatus.pr_reg = *regs;
	}

	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 = current->uid;
	psinfo.pr_gid = current->gid;
	{
		int i, len;

		set_fs(fs);

		len = current->mm->arg_end - current->mm->arg_start;
		len = len >= ELF_PRARGSZ ? ELF_PRARGSZ : len;
		(void *) copy_from_user(&psinfo.pr_psargs,
			       (const char __user *)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;

		set_fs(KERNEL_DS);
	}
	strlcpy(psinfo.pr_fname, current->comm, sizeof(psinfo.pr_fname));

	/* Try to dump the FPU. */
	prstatus.pr_fpvalid = dump_fpu (regs, &fpu);
	if (!prstatus.pr_fpvalid) {
		numnote--;
	} else {
		notes[2].name = "CORE";
		notes[2].type = NT_PRFPREG;
		notes[2].datasz = sizeof(fpu);
		notes[2].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, PAGE_SIZE);

	/* Write program headers for segments dump. */
	for(vma = current->mm->mmap, i = 0;
		i < segs && vma != NULL; vma = vma->vm_next) {
		struct elf_phdr phdr;
		size_t sz;

		i++;

		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 = PAGE_SIZE;

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

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

	set_fs(fs);

	DUMP_SEEK(dataoff);

	for(i = 0, vma = current->mm->mmap;
	    i < segs && vma != NULL;
	    vma = vma->vm_next) {
		unsigned long addr = vma->vm_start;
		unsigned long len = vma->vm_end - vma->vm_start;

		if (!maydump(vma))
			continue;
		i++;
#ifdef DEBUG
		printk("elf_core_dump: writing %08lx %lx\n", addr, len);
#endif
		DUMP_WRITE((void __user *)addr, len);
	}

	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);
	return has_dumped;
}

static int __init init_irix_binfmt(void)
{
	extern int init_inventory(void);
	extern asmlinkage unsigned long sys_call_table;
	extern asmlinkage unsigned long sys_call_table_irix5;

	init_inventory();

	/*
	 * Copy the IRIX5 syscall table (8000 bytes) into the main syscall
	 * table. The IRIX5 calls are located by an offset of 8000 bytes
	 * from the beginning of the main table.
	 */
	memcpy((void *) ((unsigned long) &sys_call_table + 8000),
		&sys_call_table_irix5, 8000);

	return register_binfmt(&irix_format);
}

static void __exit exit_irix_binfmt(void)
{
	/*
	 * Remove the Irix ELF loader.
	 */
	unregister_binfmt(&irix_format);
}

module_init(init_irix_binfmt)
module_exit(exit_irix_binfmt)