Skip to content

Commit

Permalink
pstore: Do not duplicate record metadata
Browse files Browse the repository at this point in the history 
This switches the inode-private data from carrying duplicate metadata to
keeping the record passed in during pstore_mkfile().

Signed-off-by: Kees Cook <keescook@chromium.org>
  • Loading branch information
Kees Cook committed Mar 7, 2017
1 parent 2a2b0ac commit 83f70f0
Show file tree
Hide file tree
Showing 2 changed files with 30 additions and 33 deletions.
57 changes: 28 additions & 29 deletions fs/pstore/inode.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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 {
Expand All @@ -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);
}

Expand All @@ -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;
}
Expand All @@ -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)++;
Expand All @@ -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),
Expand All @@ -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,
Expand 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)
Expand All @@ -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);
Expand Down Expand Up @@ -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;
}
Expand Down Expand Up @@ -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;
}
Expand All @@ -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:
Expand Down Expand Up @@ -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;

Expand Down
6 changes: 2 additions & 4 deletions fs/pstore/platform.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand Down

0 comments on commit 83f70f0

Please sign in to comment.