Commit 83f70f07 authored by Kees Cook's avatar Kees Cook
Browse files

pstore: Do not duplicate record metadata 



This switches the inode-private data from carrying duplicate metadata to
keeping the record passed in during pstore_mkfile().

Signed-off-by: default avatarKees Cook <keescook@chromium.org>
parent 2a2b0acf

fs/pstore/inode.c

+28 −29
Original line number Diff line number Diff line
@@ -47,12 +47,8 @@ static LIST_HEAD(allpstore); 


struct pstore_private {

	struct list_head list;

	struct pstore_info *psi;

	enum pstore_type_id type;

	u64	id;

	int	count;

	ssize_t	size;

	char    *buf;

	struct pstore_record *record;

	size_t total_size;

};



struct pstore_ftrace_seq_data {
@@ -67,7 +63,10 @@ static void free_pstore_private(struct pstore_private *private) 
{

	if (!private)

		return;

	kfree(private->buf);

	if (private->record) {

		kfree(private->record->buf);

		kfree(private->record);

	}

	kfree(private);

}
@@ -80,9 +79,9 @@ static void *pstore_ftrace_seq_start(struct seq_file *s, loff_t *pos) 
	if (!data)

		return NULL;



	data->off = ps->size % REC_SIZE;

	data->off = ps->total_size % REC_SIZE;

	data->off += *pos * REC_SIZE;

	if (data->off + REC_SIZE > ps->size) {

	if (data->off + REC_SIZE > ps->total_size) {

		kfree(data);

		return NULL;

	}
@@ -102,7 +101,7 @@ static void *pstore_ftrace_seq_next(struct seq_file *s, void *v, loff_t *pos) 
	struct pstore_ftrace_seq_data *data = v;



	data->off += REC_SIZE;

	if (data->off + REC_SIZE > ps->size)

	if (data->off + REC_SIZE > ps->total_size)

		return NULL;



	(*pos)++;
@@ -113,7 +112,9 @@ static int pstore_ftrace_seq_show(struct seq_file *s, void *v) 
{

	struct pstore_private *ps = s->private;

	struct pstore_ftrace_seq_data *data = v;

	struct pstore_ftrace_record *rec = (void *)(ps->buf + data->off);

	struct pstore_ftrace_record *rec;



	rec = (struct pstore_ftrace_record *)(ps->record->buf + data->off);



	seq_printf(s, "CPU:%d ts:%llu %08lx  %08lx  %pf <- %pF\n",

		   pstore_ftrace_decode_cpu(rec),
@@ -133,7 +134,7 @@ static const struct seq_operations pstore_ftrace_seq_ops = { 


static int pstore_check_syslog_permissions(struct pstore_private *ps)

{

	switch (ps->type) {

	switch (ps->record->type) {

	case PSTORE_TYPE_DMESG:

	case PSTORE_TYPE_CONSOLE:

		return check_syslog_permissions(SYSLOG_ACTION_READ_ALL,
@@ -149,9 +150,10 @@ static ssize_t pstore_file_read(struct file *file, char __user *userbuf, 
	struct seq_file *sf = file->private_data;

	struct pstore_private *ps = sf->private;



	if (ps->type == PSTORE_TYPE_FTRACE)

	if (ps->record->type == PSTORE_TYPE_FTRACE)

		return seq_read(file, userbuf, count, ppos);

	return simple_read_from_buffer(userbuf, count, ppos, ps->buf, ps->size);

	return simple_read_from_buffer(userbuf, count, ppos,

				       ps->record->buf, ps->total_size);

}



static int pstore_file_open(struct inode *inode, struct file *file)
@@ -165,7 +167,7 @@ static int pstore_file_open(struct inode *inode, struct file *file) 
	if (err)

		return err;



	if (ps->type == PSTORE_TYPE_FTRACE)

	if (ps->record->type == PSTORE_TYPE_FTRACE)

		sops = &pstore_ftrace_seq_ops;



	err = seq_open(file, sops);
@@ -201,17 +203,18 @@ static const struct file_operations pstore_file_operations = { 
static int pstore_unlink(struct inode *dir, struct dentry *dentry)

{

	struct pstore_private *p = d_inode(dentry)->i_private;

	struct pstore_record *record = p->record;

	int err;



	err = pstore_check_syslog_permissions(p);

	if (err)

		return err;



	if (p->psi->erase) {

		mutex_lock(&p->psi->read_mutex);

		p->psi->erase(p->type, p->id, p->count,

			      d_inode(dentry)->i_ctime, p->psi);

		mutex_unlock(&p->psi->read_mutex);

	if (record->psi->erase) {

		mutex_lock(&record->psi->read_mutex);

		record->psi->erase(record->type, record->id, record->count,

			      d_inode(dentry)->i_ctime, record->psi);

		mutex_unlock(&record->psi->read_mutex);

	} else {

		return -EPERM;

	}
@@ -323,9 +326,9 @@ int pstore_mkfile(struct pstore_record *record) 


	spin_lock_irqsave(&allpstore_lock, flags);

	list_for_each_entry(pos, &allpstore, list) {

		if (pos->type == record->type &&

		    pos->id == record->id &&

		    pos->psi == record->psi) {

		if (pos->record->type == record->type &&

		    pos->record->id == record->id &&

		    pos->record->psi == record->psi) {

			rc = -EEXIST;

			break;

		}
@@ -343,10 +346,7 @@ int pstore_mkfile(struct pstore_record *record) 
	private = kzalloc(sizeof(*private), GFP_KERNEL);

	if (!private)

		goto fail_alloc;

	private->type = record->type;

	private->id = record->id;

	private->count = record->count;

	private->psi = record->psi;

	private->record = record;



	switch (record->type) {

	case PSTORE_TYPE_DMESG:
@@ -402,8 +402,7 @@ int pstore_mkfile(struct pstore_record *record) 
	if (!dentry)

		goto fail_lockedalloc;



	private->buf = record->buf;

	inode->i_size = private->size = size;

	inode->i_size = private->total_size = size;



	inode->i_private = private;

fs/pstore/platform.c

+2 −4
Original line number Diff line number Diff line
@@ -852,14 +852,12 @@ void pstore_get_records(int quiet) 
		decompress_record(record);

		rc = pstore_mkfile(record);

		if (rc) {

			/* pstore_mkfile() did not take buf, so free it. */

			/* pstore_mkfile() did not take record, so free it. */

			kfree(record->buf);

			kfree(record);

			if (rc != -EEXIST || !quiet)

				failed++;

		}



		/* Reset for next record. */

		kfree(record);

	}

	if (psi->close)

		psi->close(psi);