/*
* linux/fs/hpfs/dentry.c
*
* Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
*
* dcache operations
*/
#include "hpfs_fn.h"
/*
* Note: the dentry argument is the parent dentry.
*/
static int hpfs_hash_dentry(const struct dentry *dentry, struct qstr *qstr)
{
unsigned long hash;
int i;
unsigned l = qstr->len;
if (l == 1) if (qstr->name[0]=='.') goto x;
if (l == 2) if (qstr->name[0]=='.' || qstr->name[1]=='.') goto x;
hpfs_adjust_length(qstr->name, &l);
/*if (hpfs_chk_name(qstr->name,&l))*/
/*return -ENAMETOOLONG;*/
/*return -ENOENT;*/
x:
hash = init_name_hash(dentry);
for (i = 0; i < l; i++)
hash = partial_name_hash(hpfs_upcase(hpfs_sb(dentry->d_sb)->sb_cp_table,qstr->name[i]), hash);
qstr->hash = end_name_hash(hash);
return 0;
}
static int hpfs_compare_dentry(const struct dentry *dentry,
unsigned int len, const char *str, const struct qstr *name)
{
unsigned al = len;
unsigned bl = name->len;
hpfs_adjust_length(str, &al);
/*hpfs_adjust_length(b->name, &bl);*/
/*
* 'str' is the nane of an already existing dentry, so the name
* must be valid. 'name' must be validated first.
*/
if (hpfs_chk_name(name->name, &bl))
return 1;
if (hpfs_compare_names(dentry->d_sb, str, al, name->name, bl, 0))
return 1;
return 0;
}
const struct dentry_operations hpfs_dentry_operations = {
.d_hash = hpfs_hash_dentry,
.d_compare = hpfs_compare_dentry,
};
bmit' value='switch'/>
dm crypt: replace RCU read-side section with rwsem
The lockdep splat below hints at a bug in RCU usage in dm-crypt that
was introduced with commit c538f6ec9f56 ("dm crypt: add ability to use
keys from the kernel key retention service"). The kernel keyring
function user_key_payload() is in fact a wrapper for
rcu_dereference_protected() which must not be called with only
rcu_read_lock() section mark.
Unfortunately the kernel keyring subsystem doesn't currently provide
an interface that allows the use of an RCU read-side section. So for
now we must drop RCU in favour of rwsem until a proper function is
made available in the kernel keyring subsystem.
===============================
[ INFO: suspicious RCU usage. ]
4.10.0-rc5 #2 Not tainted
-------------------------------
./include/keys/user-type.h:53 suspicious rcu_dereference_protected() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
2 locks held by cryptsetup/6464:
#0: (&md->type_lock){+.+.+.}, at: [<ffffffffa02472a2>] dm_lock_md_type+0x12/0x20 [dm_mod]
#1: (rcu_read_lock){......}, at: [<ffffffffa02822f8>] crypt_set_key+0x1d8/0x4b0 [dm_crypt]
stack backtrace:
CPU: 1 PID: 6464 Comm: cryptsetup Not tainted 4.10.0-rc5 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014
Call Trace:
dump_stack+0x67/0x92
lockdep_rcu_suspicious+0xc5/0x100
crypt_set_key+0x351/0x4b0 [dm_crypt]
? crypt_set_key+0x1d8/0x4b0 [dm_crypt]
crypt_ctr+0x341/0xa53 [dm_crypt]
dm_table_add_target+0x147/0x330 [dm_mod]
table_load+0x111/0x350 [dm_mod]
? retrieve_status+0x1c0/0x1c0 [dm_mod]
ctl_ioctl+0x1f5/0x510 [dm_mod]
dm_ctl_ioctl+0xe/0x20 [dm_mod]
do_vfs_ioctl+0x8e/0x690
? ____fput+0x9/0x10
? task_work_run+0x7e/0xa0
? trace_hardirqs_on_caller+0x122/0x1b0
SyS_ioctl+0x3c/0x70
entry_SYSCALL_64_fastpath+0x18/0xad
RIP: 0033:0x7f392c9a4ec7
RSP: 002b:00007ffef6383378 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffef63830a0 RCX: 00007f392c9a4ec7
RDX: 000000000124fcc0 RSI: 00000000c138fd09 RDI: 0000000000000005
RBP: 00007ffef6383090 R08: 00000000ffffffff R09: 00000000012482b0
R10: 2a28205d34383336 R11: 0000000000000246 R12: 00007f392d803a08
R13: 00007ffef63831e0 R14: 0000000000000000 R15: 00007f392d803a0b
Fixes: c538f6ec9f56 ("dm crypt: add ability to use keys from the kernel key retention service")
Reported-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Ondrej Kozina <okozina@redhat.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>