[net-next-2.6.git] / fs / proc / kcore.c

/*
 *	fs/proc/kcore.c kernel ELF core dumper
 *
 *	Modelled on fs/exec.c:aout_core_dump()
 *	Jeremy Fitzhardinge <jeremy@sw.oz.au>
 *	ELF version written by David Howells <David.Howells@nexor.co.uk>
 *	Modified and incorporated into 2.3.x by Tigran Aivazian <tigran@veritas.com>
 *	Support to dump vmalloc'd areas (ELF only), Tigran Aivazian <tigran@veritas.com>
 *	Safe accesses to vmalloc/direct-mapped discontiguous areas, Kanoj Sarcar <kanoj@sgi.com>
 */

#include <linux/mm.h>
#include <linux/proc_fs.h>
#include <linux/user.h>
#include <linux/capability.h>
#include <linux/elf.h>
#include <linux/elfcore.h>
#include <linux/vmalloc.h>
#include <linux/highmem.h>
#include <linux/init.h>
#include <asm/uaccess.h>
#include <asm/io.h>

#define CORE_STR "CORE"

static int open_kcore(struct inode * inode, struct file * filp)
{
	return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
}

static ssize_t read_kcore(struct file *, char __user *, size_t, loff_t *);

const struct file_operations proc_kcore_operations = {
	.read		= read_kcore,
	.open		= open_kcore,
};

#ifndef kc_vaddr_to_offset
#define	kc_vaddr_to_offset(v) ((v) - PAGE_OFFSET)
#endif
#ifndef	kc_offset_to_vaddr
#define	kc_offset_to_vaddr(o) ((o) + PAGE_OFFSET)
#endif

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

static struct kcore_list *kclist;
static DEFINE_RWLOCK(kclist_lock);

void
kclist_add(struct kcore_list *new, void *addr, size_t size)
{
	new->addr = (unsigned long)addr;
	new->size = size;

	write_lock(&kclist_lock);
	new->next = kclist;
	kclist = new;
	write_unlock(&kclist_lock);
}

static size_t get_kcore_size(int *nphdr, size_t *elf_buflen)
{
	size_t try, size;
	struct kcore_list *m;

	*nphdr = 1; /* PT_NOTE */
	size = 0;

	for (m=kclist; m; m=m->next) {
		try = kc_vaddr_to_offset((size_t)m->addr + m->size);
		if (try > size)
			size = try;
		*nphdr = *nphdr + 1;
	}
	*elf_buflen =	sizeof(struct elfhdr) + 
			(*nphdr + 2)*sizeof(struct elf_phdr) + 
			3 * ((sizeof(struct elf_note)) +
			     roundup(sizeof(CORE_STR), 4)) +
			roundup(sizeof(struct elf_prstatus), 4) +
			roundup(sizeof(struct elf_prpsinfo), 4) +
			roundup(sizeof(struct task_struct), 4);
	*elf_buflen = PAGE_ALIGN(*elf_buflen);
	return size + *elf_buflen;
}


/*****************************************************************************/
/*
 * determine size of ELF note
 */
static int notesize(struct memelfnote *en)
{
	int sz;

	sz = sizeof(struct elf_note);
	sz += roundup((strlen(en->name) + 1), 4);
	sz += roundup(en->datasz, 4);

	return sz;
} /* end notesize() */

/*****************************************************************************/
/*
 * store a note in the header buffer
 */
static char *storenote(struct memelfnote *men, char *bufp)
{
	struct elf_note en;

#define DUMP_WRITE(addr,nr) do { memcpy(bufp,addr,nr); bufp += nr; } while(0)

	en.n_namesz = strlen(men->name) + 1;
	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 */
	bufp = (char*) roundup((unsigned long)bufp,4);
	DUMP_WRITE(men->data, men->datasz);
	bufp = (char*) roundup((unsigned long)bufp,4);

#undef DUMP_WRITE

	return bufp;
} /* end storenote() */

/*
 * store an ELF coredump header in the supplied buffer
 * nphdr is the number of elf_phdr to insert
 */
static void elf_kcore_store_hdr(char *bufp, int nphdr, int dataoff)
{
	struct elf_prstatus prstatus;	/* NT_PRSTATUS */
	struct elf_prpsinfo prpsinfo;	/* NT_PRPSINFO */
	struct elf_phdr *nhdr, *phdr;
	struct elfhdr *elf;
	struct memelfnote notes[3];
	off_t offset = 0;
	struct kcore_list *m;

	/* setup ELF header */
	elf = (struct elfhdr *) bufp;
	bufp += sizeof(struct elfhdr);
	offset += sizeof(struct elfhdr);
	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;
	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(struct elfhdr);
	elf->e_shoff	= 0;
#if defined(CONFIG_H8300)
	elf->e_flags	= ELF_FLAGS;
#else
	elf->e_flags	= 0;
#endif
	elf->e_ehsize	= sizeof(struct elfhdr);
	elf->e_phentsize= sizeof(struct elf_phdr);
	elf->e_phnum	= nphdr;
	elf->e_shentsize= 0;
	elf->e_shnum	= 0;
	elf->e_shstrndx	= 0;

	/* setup ELF PT_NOTE program header */
	nhdr = (struct elf_phdr *) bufp;
	bufp += sizeof(struct elf_phdr);
	offset += sizeof(struct elf_phdr);
	nhdr->p_type	= PT_NOTE;
	nhdr->p_offset	= 0;
	nhdr->p_vaddr	= 0;
	nhdr->p_paddr	= 0;
	nhdr->p_filesz	= 0;
	nhdr->p_memsz	= 0;
	nhdr->p_flags	= 0;
	nhdr->p_align	= 0;

	/* setup ELF PT_LOAD program header for every area */
	for (m=kclist; m; m=m->next) {
		phdr = (struct elf_phdr *) bufp;
		bufp += sizeof(struct elf_phdr);
		offset += sizeof(struct elf_phdr);

		phdr->p_type	= PT_LOAD;
		phdr->p_flags	= PF_R|PF_W|PF_X;
		phdr->p_offset	= kc_vaddr_to_offset(m->addr) + dataoff;
		phdr->p_vaddr	= (size_t)m->addr;
		phdr->p_paddr	= 0;
		phdr->p_filesz	= phdr->p_memsz	= m->size;
		phdr->p_align	= PAGE_SIZE;
	}

	/*
	 * Set up the notes in similar form to SVR4 core dumps made
	 * with info from their /proc.
	 */
	nhdr->p_offset	= offset;

	/* set up the process status */
	notes[0].name = CORE_STR;
	notes[0].type = NT_PRSTATUS;
	notes[0].datasz = sizeof(struct elf_prstatus);
	notes[0].data = &prstatus;

	memset(&prstatus, 0, sizeof(struct elf_prstatus));

	nhdr->p_filesz	= notesize(&notes[0]);
	bufp = storenote(&notes[0], bufp);

	/* set up the process info */
	notes[1].name	= CORE_STR;
	notes[1].type	= NT_PRPSINFO;
	notes[1].datasz	= sizeof(struct elf_prpsinfo);
	notes[1].data	= &prpsinfo;

	memset(&prpsinfo, 0, sizeof(struct elf_prpsinfo));
	prpsinfo.pr_state	= 0;
	prpsinfo.pr_sname	= 'R';
	prpsinfo.pr_zomb	= 0;

	strcpy(prpsinfo.pr_fname, "vmlinux");
	strncpy(prpsinfo.pr_psargs, saved_command_line, ELF_PRARGSZ);

	nhdr->p_filesz	+= notesize(&notes[1]);
	bufp = storenote(&notes[1], bufp);

	/* set up the task structure */
	notes[2].name	= CORE_STR;
	notes[2].type	= NT_TASKSTRUCT;
	notes[2].datasz	= sizeof(struct task_struct);
	notes[2].data	= current;

	nhdr->p_filesz	+= notesize(&notes[2]);
	bufp = storenote(&notes[2], bufp);

} /* end elf_kcore_store_hdr() */

/*****************************************************************************/
/*
 * read from the ELF header and then kernel memory
 */
static ssize_t
read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos)
{
	ssize_t acc = 0;
	size_t size, tsz;
	size_t elf_buflen;
	int nphdr;
	unsigned long start;

	read_lock(&kclist_lock);
	proc_root_kcore->size = size = get_kcore_size(&nphdr, &elf_buflen);
	if (buflen == 0 || *fpos >= size) {
		read_unlock(&kclist_lock);
		return 0;
	}

	/* trim buflen to not go beyond EOF */
	if (buflen > size - *fpos)
		buflen = size - *fpos;

	/* construct an ELF core header if we'll need some of it */
	if (*fpos < elf_buflen) {
		char * elf_buf;

		tsz = elf_buflen - *fpos;
		if (buflen < tsz)
			tsz = buflen;
		elf_buf = kzalloc(elf_buflen, GFP_ATOMIC);
		if (!elf_buf) {
			read_unlock(&kclist_lock);
			return -ENOMEM;
		}
		elf_kcore_store_hdr(elf_buf, nphdr, elf_buflen);
		read_unlock(&kclist_lock);
		if (copy_to_user(buffer, elf_buf + *fpos, tsz)) {
			kfree(elf_buf);
			return -EFAULT;
		}
		kfree(elf_buf);
		buflen -= tsz;
		*fpos += tsz;
		buffer += tsz;
		acc += tsz;

		/* leave now if filled buffer already */
		if (buflen == 0)
			return acc;
	} else
		read_unlock(&kclist_lock);

	/*
	 * Check to see if our file offset matches with any of
	 * the addresses in the elf_phdr on our list.
	 */
	start = kc_offset_to_vaddr(*fpos - elf_buflen);
	if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
		tsz = buflen;
		
	while (buflen) {
		struct kcore_list *m;

		read_lock(&kclist_lock);
		for (m=kclist; m; m=m->next) {
			if (start >= m->addr && start < (m->addr+m->size))
				break;
		}
		read_unlock(&kclist_lock);

		if (m == NULL) {
			if (clear_user(buffer, tsz))
				return -EFAULT;
		} else if (is_vmalloc_addr((void *)start)) {
			char * elf_buf;
			struct vm_struct *m;
			unsigned long curstart = start;
			unsigned long cursize = tsz;

			elf_buf = kzalloc(tsz, GFP_KERNEL);
			if (!elf_buf)
				return -ENOMEM;

			read_lock(&vmlist_lock);
			for (m=vmlist; m && cursize; m=m->next) {
				unsigned long vmstart;
				unsigned long vmsize;
				unsigned long msize = m->size - PAGE_SIZE;

				if (((unsigned long)m->addr + msize) < 
								curstart)
					continue;
				if ((unsigned long)m->addr > (curstart + 
								cursize))
					break;
				vmstart = (curstart < (unsigned long)m->addr ? 
					(unsigned long)m->addr : curstart);
				if (((unsigned long)m->addr + msize) > 
							(curstart + cursize))
					vmsize = curstart + cursize - vmstart;
				else
					vmsize = (unsigned long)m->addr + 
							msize - vmstart;
				curstart = vmstart + vmsize;
				cursize -= vmsize;
				/* don't dump ioremap'd stuff! (TA) */
				if (m->flags & VM_IOREMAP)
					continue;
				memcpy(elf_buf + (vmstart - start),
					(char *)vmstart, vmsize);
			}
			read_unlock(&vmlist_lock);
			if (copy_to_user(buffer, elf_buf, tsz)) {
				kfree(elf_buf);
				return -EFAULT;
			}
			kfree(elf_buf);
		} else {
			if (kern_addr_valid(start)) {
				unsigned long n;

				n = copy_to_user(buffer, (char *)start, tsz);
				/*
				 * We cannot distingush between fault on source
				 * and fault on destination. When this happens
				 * we clear too and hope it will trigger the
				 * EFAULT again.
				 */
				if (n) { 
					if (clear_user(buffer + tsz - n,
								n))
						return -EFAULT;
				}
			} else {
				if (clear_user(buffer, tsz))
					return -EFAULT;
			}
		}
		buflen -= tsz;
		*fpos += tsz;
		buffer += tsz;
		acc += tsz;
		start += tsz;
		tsz = (buflen > PAGE_SIZE ? PAGE_SIZE : buflen);
	}

	return acc;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* fs/proc/kcore.c kernel ELF core dumper
	3	*
	4	* Modelled on fs/exec.c:aout_core_dump()
	5	* Jeremy Fitzhardinge <jeremy@sw.oz.au>
	6	* ELF version written by David Howells <David.Howells@nexor.co.uk>
	7	* Modified and incorporated into 2.3.x by Tigran Aivazian <tigran@veritas.com>
	8	* Support to dump vmalloc'd areas (ELF only), Tigran Aivazian <tigran@veritas.com>
	9	* Safe accesses to vmalloc/direct-mapped discontiguous areas, Kanoj Sarcar <kanoj@sgi.com>
	10	*/
	11
1da177e4 LT	12	#include <linux/mm.h>
	13	#include <linux/proc_fs.h>
	14	#include <linux/user.h>
16f7e0fe	15	#include <linux/capability.h>
1da177e4 LT	16	#include <linux/elf.h>
	17	#include <linux/elfcore.h>
	18	#include <linux/vmalloc.h>
	19	#include <linux/highmem.h>
	20	#include <linux/init.h>
	21	#include <asm/uaccess.h>
	22	#include <asm/io.h>
	23
36027604	24	#define CORE_STR "CORE"
1da177e4 LT	25
	26	static int open_kcore(struct inode * inode, struct file * filp)
	27	{
	28	return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
	29	}
	30
	31	static ssize_t read_kcore(struct file , char __user , size_t, loff_t *);
	32
4b6f5d20	33	const struct file_operations proc_kcore_operations = {
1da177e4 LT	34	.read = read_kcore,
	35	.open = open_kcore,
	36	};
	37
	38	#ifndef kc_vaddr_to_offset
	39	#define kc_vaddr_to_offset(v) ((v) - PAGE_OFFSET)
	40	#endif
	41	#ifndef kc_offset_to_vaddr
	42	#define kc_offset_to_vaddr(o) ((o) + PAGE_OFFSET)
	43	#endif
	44
1da177e4 LT	45	/* An ELF note in memory */
	46	struct memelfnote
	47	{
	48	const char *name;
	49	int type;
	50	unsigned int datasz;
	51	void *data;
	52	};
	53
	54	static struct kcore_list *kclist;
	55	static DEFINE_RWLOCK(kclist_lock);
	56
	57	void
	58	kclist_add(struct kcore_list new, void addr, size_t size)
	59	{
	60	new->addr = (unsigned long)addr;
	61	new->size = size;
	62
	63	write_lock(&kclist_lock);
	64	new->next = kclist;
	65	kclist = new;
	66	write_unlock(&kclist_lock);
	67	}
	68
	69	static size_t get_kcore_size(int nphdr, size_t elf_buflen)
	70	{
	71	size_t try, size;
	72	struct kcore_list *m;
	73
	74	nphdr = 1; / PT_NOTE */
	75	size = 0;
	76
	77	for (m=kclist; m; m=m->next) {
	78	try = kc_vaddr_to_offset((size_t)m->addr + m->size);
	79	if (try > size)
	80	size = try;
	81	nphdr = nphdr + 1;
	82	}
	83	*elf_buflen = sizeof(struct elfhdr) +
	84	(nphdr + 2)sizeof(struct elf_phdr) +
36027604 MD	85	3 * ((sizeof(struct elf_note)) +
	86	roundup(sizeof(CORE_STR), 4)) +
	87	roundup(sizeof(struct elf_prstatus), 4) +
	88	roundup(sizeof(struct elf_prpsinfo), 4) +
	89	roundup(sizeof(struct task_struct), 4);
1da177e4 LT	90	elf_buflen = PAGE_ALIGN(elf_buflen);
	91	return size + *elf_buflen;
	92	}
	93
	94
	95	/*****************************************************************************/
	96	/*
	97	* determine size of ELF note
	98	*/
	99	static int notesize(struct memelfnote *en)
	100	{
	101	int sz;
	102
	103	sz = sizeof(struct elf_note);
632dd205	104	sz += roundup((strlen(en->name) + 1), 4);
1da177e4 LT	105	sz += roundup(en->datasz, 4);
	106
	107	return sz;
	108	} /* end notesize() */
	109
	110	/*****************************************************************************/
	111	/*
	112	* store a note in the header buffer
	113	*/
	114	static char storenote(struct memelfnote men, char *bufp)
	115	{
	116	struct elf_note en;
	117
	118	#define DUMP_WRITE(addr,nr) do { memcpy(bufp,addr,nr); bufp += nr; } while(0)
	119
632dd205	120	en.n_namesz = strlen(men->name) + 1;
1da177e4 LT	121	en.n_descsz = men->datasz;
	122	en.n_type = men->type;
	123
	124	DUMP_WRITE(&en, sizeof(en));
	125	DUMP_WRITE(men->name, en.n_namesz);
	126
	127	/* XXX - cast from long long to long to avoid need for libgcc.a */
	128	bufp = (char*) roundup((unsigned long)bufp,4);
	129	DUMP_WRITE(men->data, men->datasz);
	130	bufp = (char*) roundup((unsigned long)bufp,4);
	131
	132	#undef DUMP_WRITE
	133
	134	return bufp;
	135	} /* end storenote() */
	136
	137	/*
	138	* store an ELF coredump header in the supplied buffer
	139	* nphdr is the number of elf_phdr to insert
	140	*/
	141	static void elf_kcore_store_hdr(char *bufp, int nphdr, int dataoff)
	142	{
	143	struct elf_prstatus prstatus; /* NT_PRSTATUS */
	144	struct elf_prpsinfo prpsinfo; /* NT_PRPSINFO */
	145	struct elf_phdr nhdr, phdr;
	146	struct elfhdr *elf;
	147	struct memelfnote notes[3];
	148	off_t offset = 0;
	149	struct kcore_list *m;
	150
	151	/* setup ELF header */
	152	elf = (struct elfhdr *) bufp;
	153	bufp += sizeof(struct elfhdr);
	154	offset += sizeof(struct elfhdr);
	155	memcpy(elf->e_ident, ELFMAG, SELFMAG);
	156	elf->e_ident[EI_CLASS] = ELF_CLASS;
	157	elf->e_ident[EI_DATA] = ELF_DATA;
	158	elf->e_ident[EI_VERSION]= EV_CURRENT;
	159	elf->e_ident[EI_OSABI] = ELF_OSABI;
	160	memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
	161	elf->e_type = ET_CORE;
	162	elf->e_machine = ELF_ARCH;
	163	elf->e_version = EV_CURRENT;
	164	elf->e_entry = 0;
	165	elf->e_phoff = sizeof(struct elfhdr);
	166	elf->e_shoff = 0;
	167	#if defined(CONFIG_H8300)
	168	elf->e_flags = ELF_FLAGS;
	169	#else
	170	elf->e_flags = 0;
	171	#endif
	172	elf->e_ehsize = sizeof(struct elfhdr);
	173	elf->e_phentsize= sizeof(struct elf_phdr);
	174	elf->e_phnum = nphdr;
	175	elf->e_shentsize= 0;
	176	elf->e_shnum = 0;
	177	elf->e_shstrndx = 0;
	178
	179	/* setup ELF PT_NOTE program header */
	180	nhdr = (struct elf_phdr *) bufp;
	181	bufp += sizeof(struct elf_phdr);
	182	offset += sizeof(struct elf_phdr);
	183	nhdr->p_type = PT_NOTE;
	184	nhdr->p_offset = 0;
185	nhdr->p_vaddr = 0;
186	nhdr->p_paddr = 0;
187	nhdr->p_filesz = 0;
188	nhdr->p_memsz = 0;
189	nhdr->p_flags = 0;
190	nhdr->p_align = 0;
191
192	/* setup ELF PT_LOAD program header for every area */
193	for (m=kclist; m; m=m->next) {
194	phdr = (struct elf_phdr *) bufp;
195	bufp += sizeof(struct elf_phdr);
196	offset += sizeof(struct elf_phdr);
197
198	phdr->p_type = PT_LOAD;
199	phdr->p_flags = PF_R\|PF_W\|PF_X;
200	phdr->p_offset = kc_vaddr_to_offset(m->addr) + dataoff;
201	phdr->p_vaddr = (size_t)m->addr;
202	phdr->p_paddr = 0;
203	phdr->p_filesz = phdr->p_memsz = m->size;
204	phdr->p_align = PAGE_SIZE;
205	}
206
207	/*
208	* Set up the notes in similar form to SVR4 core dumps made
209	* with info from their /proc.
210	*/
211	nhdr->p_offset = offset;
212
213	/* set up the process status */
36027604	214	notes[0].name = CORE_STR;
1da177e4 LT	215	notes[0].type = NT_PRSTATUS;
	216	notes[0].datasz = sizeof(struct elf_prstatus);
	217	notes[0].data = &prstatus;
	218
	219	memset(&prstatus, 0, sizeof(struct elf_prstatus));
	220
	221	nhdr->p_filesz = notesize(&notes[0]);
	222	bufp = storenote(&notes[0], bufp);
	223
	224	/* set up the process info */
36027604	225	notes[1].name = CORE_STR;
1da177e4 LT	226	notes[1].type = NT_PRPSINFO;
	227	notes[1].datasz = sizeof(struct elf_prpsinfo);
	228	notes[1].data = &prpsinfo;
	229
	230	memset(&prpsinfo, 0, sizeof(struct elf_prpsinfo));
	231	prpsinfo.pr_state = 0;
	232	prpsinfo.pr_sname = 'R';
	233	prpsinfo.pr_zomb = 0;
	234
	235	strcpy(prpsinfo.pr_fname, "vmlinux");
	236	strncpy(prpsinfo.pr_psargs, saved_command_line, ELF_PRARGSZ);
	237
	238	nhdr->p_filesz += notesize(&notes[1]);
	239	bufp = storenote(&notes[1], bufp);
	240
	241	/* set up the task structure */
36027604	242	notes[2].name = CORE_STR;
1da177e4 LT	243	notes[2].type = NT_TASKSTRUCT;
	244	notes[2].datasz = sizeof(struct task_struct);
	245	notes[2].data = current;
	246
	247	nhdr->p_filesz += notesize(&notes[2]);
	248	bufp = storenote(&notes[2], bufp);
	249
	250	} /* end elf_kcore_store_hdr() */
	251
	252	/*****************************************************************************/
	253	/*
	254	* read from the ELF header and then kernel memory
	255	*/
	256	static ssize_t
	257	read_kcore(struct file file, char __user buffer, size_t buflen, loff_t *fpos)
	258	{
	259	ssize_t acc = 0;
	260	size_t size, tsz;
	261	size_t elf_buflen;
	262	int nphdr;
	263	unsigned long start;
	264
	265	read_lock(&kclist_lock);
	266	proc_root_kcore->size = size = get_kcore_size(&nphdr, &elf_buflen);
	267	if (buflen == 0 \|\| *fpos >= size) {
	268	read_unlock(&kclist_lock);
	269	return 0;
	270	}
	271
	272	/* trim buflen to not go beyond EOF */
	273	if (buflen > size - *fpos)
	274	buflen = size - *fpos;
	275
	276	/* construct an ELF core header if we'll need some of it */
	277	if (*fpos < elf_buflen) {
	278	char * elf_buf;
	279
	280	tsz = elf_buflen - *fpos;
	281	if (buflen < tsz)
	282	tsz = buflen;
f8314dc6	283	elf_buf = kzalloc(elf_buflen, GFP_ATOMIC);
1da177e4 LT	284	if (!elf_buf) {
	285	read_unlock(&kclist_lock);
	286	return -ENOMEM;
	287	}
1da177e4 LT	288	elf_kcore_store_hdr(elf_buf, nphdr, elf_buflen);
	289	read_unlock(&kclist_lock);
	290	if (copy_to_user(buffer, elf_buf + *fpos, tsz)) {
	291	kfree(elf_buf);
	292	return -EFAULT;
	293	}
	294	kfree(elf_buf);
	295	buflen -= tsz;
	296	*fpos += tsz;
	297	buffer += tsz;
	298	acc += tsz;
	299
	300	/* leave now if filled buffer already */
	301	if (buflen == 0)
	302	return acc;
	303	} else
	304	read_unlock(&kclist_lock);
	305
	306	/*
	307	* Check to see if our file offset matches with any of
	308	* the addresses in the elf_phdr on our list.
	309	*/
	310	start = kc_offset_to_vaddr(*fpos - elf_buflen);
	311	if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
	312	tsz = buflen;
	313
	314	while (buflen) {
	315	struct kcore_list *m;
	316
	317	read_lock(&kclist_lock);
	318	for (m=kclist; m; m=m->next) {
	319	if (start >= m->addr && start < (m->addr+m->size))
	320	break;
	321	}
	322	read_unlock(&kclist_lock);
	323
	324	if (m == NULL) {
	325	if (clear_user(buffer, tsz))
	326	return -EFAULT;
9e2779fa	327	} else if (is_vmalloc_addr((void *)start)) {
1da177e4 LT	328	char * elf_buf;
	329	struct vm_struct *m;
	330	unsigned long curstart = start;
	331	unsigned long cursize = tsz;
	332
f8314dc6	333	elf_buf = kzalloc(tsz, GFP_KERNEL);
1da177e4 LT	334	if (!elf_buf)
1da177e4 LT	335	return -ENOMEM;
1da177e4 LT	336
	337	read_lock(&vmlist_lock);
	338	for (m=vmlist; m && cursize; m=m->next) {
	339	unsigned long vmstart;
	340	unsigned long vmsize;
	341	unsigned long msize = m->size - PAGE_SIZE;
	342
	343	if (((unsigned long)m->addr + msize) <
	344	curstart)
	345	continue;
	346	if ((unsigned long)m->addr > (curstart +
	347	cursize))
	348	break;
	349	vmstart = (curstart < (unsigned long)m->addr ?
	350	(unsigned long)m->addr : curstart);
	351	if (((unsigned long)m->addr + msize) >
	352	(curstart + cursize))
	353	vmsize = curstart + cursize - vmstart;
	354	else
	355	vmsize = (unsigned long)m->addr +
	356	msize - vmstart;
	357	curstart = vmstart + vmsize;
	358	cursize -= vmsize;
	359	/* don't dump ioremap'd stuff! (TA) */
	360	if (m->flags & VM_IOREMAP)
	361	continue;
	362	memcpy(elf_buf + (vmstart - start),
	363	(char *)vmstart, vmsize);
	364	}
	365	read_unlock(&vmlist_lock);
	366	if (copy_to_user(buffer, elf_buf, tsz)) {
	367	kfree(elf_buf);
	368	return -EFAULT;
	369	}
	370	kfree(elf_buf);
	371	} else {
	372	if (kern_addr_valid(start)) {
	373	unsigned long n;
	374
	375	n = copy_to_user(buffer, (char *)start, tsz);
	376	/*
	377	* We cannot distingush between fault on source
	378	* and fault on destination. When this happens
	379	* we clear too and hope it will trigger the
	380	* EFAULT again.
	381	*/
	382	if (n) {
	383	if (clear_user(buffer + tsz - n,
0635170b	384	n))
1da177e4 LT	385	return -EFAULT;
	386	}
	387	} else {
	388	if (clear_user(buffer, tsz))
	389	return -EFAULT;
	390	}
	391	}
	392	buflen -= tsz;
	393	*fpos += tsz;
	394	buffer += tsz;
	395	acc += tsz;
	396	start += tsz;
	397	tsz = (buflen > PAGE_SIZE ? PAGE_SIZE : buflen);
	398	}
	399
	400	return acc;
	401	}