Revision 798523973dcc93c2440932dc4dfe76fbf571f668 authored by Sudeep Holla on 04 March 2015, 17:07:57 UTC, committed by Felipe Balbi on 09 March 2015, 15:44:08 UTC
Use spin_{un,}lock_irq{save,restore} in isp1760_udc_{start,stop} to prevent following potentially deadlock scenario between isp1760_udc_{start,stop} and isp1760_udc_irq : ================================= [ INFO: inconsistent lock state ] 4.0.0-rc2-00004-gf7bb2ef60173 #51 Not tainted --------------------------------- inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage. in:imklog/2118 [HC1[1]:SC0[0]:HE0:SE1] takes: (&(&udc->lock)->rlock){?.+...}, at: [<c0397a93>] isp1760_udc_irq+0x367/0x9dc {HARDIRQ-ON-W} state was registered at: [<c05135b3>] _raw_spin_lock+0x23/0x30 [<c0396b87>] isp1760_udc_start+0x23/0xf8 [<c039dc21>] udc_bind_to_driver+0x71/0xb0 [<c039de4f>] usb_gadget_probe_driver+0x53/0x9c [<bf80d0df>] usb_composite_probe+0x8a/0xa4 [libcomposite] [<bf8311a7>] 0xbf8311a7 [<c00088c5>] do_one_initcall+0x8d/0x17c [<c050b92d>] do_init_module+0x49/0x148 [<c0087323>] load_module+0xb7f/0xbc4 [<c0087471>] SyS_finit_module+0x51/0x74 [<c000d8c1>] ret_fast_syscall+0x1/0x68 irq event stamp: 4966 hardirqs last enabled at (4965): [<c05137df>] _raw_spin_unlock_irq+0x1f/0x24 hardirqs last disabled at (4966): [<c00110b3>] __irq_svc+0x33/0x64 softirqs last enabled at (4458): [<c0023475>] __do_softirq+0x23d/0x2d0 softirqs last disabled at (4389): [<c002380b>] irq_exit+0xef/0x15c other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&udc->lock)->rlock); <Interrupt> lock(&(&udc->lock)->rlock); *** DEADLOCK *** 1 lock held by in:imklog/2118: #0: (&f->f_pos_lock){+.+.+.}, at: [<c010a101>] __fdget_pos+0x31/0x34 Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Felipe Balbi <balbi@ti.com>
1 parent 9eccca0
ts_kmp.c
/*
* lib/ts_kmp.c Knuth-Morris-Pratt text search implementation
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Authors: Thomas Graf <tgraf@suug.ch>
*
* ==========================================================================
*
* Implements a linear-time string-matching algorithm due to Knuth,
* Morris, and Pratt [1]. Their algorithm avoids the explicit
* computation of the transition function DELTA altogether. Its
* matching time is O(n), for n being length(text), using just an
* auxiliary function PI[1..m], for m being length(pattern),
* precomputed from the pattern in time O(m). The array PI allows
* the transition function DELTA to be computed efficiently
* "on the fly" as needed. Roughly speaking, for any state
* "q" = 0,1,...,m and any character "a" in SIGMA, the value
* PI["q"] contains the information that is independent of "a" and
* is needed to compute DELTA("q", "a") [2]. Since the array PI
* has only m entries, whereas DELTA has O(m|SIGMA|) entries, we
* save a factor of |SIGMA| in the preprocessing time by computing
* PI rather than DELTA.
*
* [1] Cormen, Leiserson, Rivest, Stein
* Introdcution to Algorithms, 2nd Edition, MIT Press
* [2] See finite automation theory
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/textsearch.h>
struct ts_kmp
{
u8 * pattern;
unsigned int pattern_len;
unsigned int prefix_tbl[0];
};
static unsigned int kmp_find(struct ts_config *conf, struct ts_state *state)
{
struct ts_kmp *kmp = ts_config_priv(conf);
unsigned int i, q = 0, text_len, consumed = state->offset;
const u8 *text;
const int icase = conf->flags & TS_IGNORECASE;
for (;;) {
text_len = conf->get_next_block(consumed, &text, conf, state);
if (unlikely(text_len == 0))
break;
for (i = 0; i < text_len; i++) {
while (q > 0 && kmp->pattern[q]
!= (icase ? toupper(text[i]) : text[i]))
q = kmp->prefix_tbl[q - 1];
if (kmp->pattern[q]
== (icase ? toupper(text[i]) : text[i]))
q++;
if (unlikely(q == kmp->pattern_len)) {
state->offset = consumed + i + 1;
return state->offset - kmp->pattern_len;
}
}
consumed += text_len;
}
return UINT_MAX;
}
static inline void compute_prefix_tbl(const u8 *pattern, unsigned int len,
unsigned int *prefix_tbl, int flags)
{
unsigned int k, q;
const u8 icase = flags & TS_IGNORECASE;
for (k = 0, q = 1; q < len; q++) {
while (k > 0 && (icase ? toupper(pattern[k]) : pattern[k])
!= (icase ? toupper(pattern[q]) : pattern[q]))
k = prefix_tbl[k-1];
if ((icase ? toupper(pattern[k]) : pattern[k])
== (icase ? toupper(pattern[q]) : pattern[q]))
k++;
prefix_tbl[q] = k;
}
}
static struct ts_config *kmp_init(const void *pattern, unsigned int len,
gfp_t gfp_mask, int flags)
{
struct ts_config *conf;
struct ts_kmp *kmp;
int i;
unsigned int prefix_tbl_len = len * sizeof(unsigned int);
size_t priv_size = sizeof(*kmp) + len + prefix_tbl_len;
conf = alloc_ts_config(priv_size, gfp_mask);
if (IS_ERR(conf))
return conf;
conf->flags = flags;
kmp = ts_config_priv(conf);
kmp->pattern_len = len;
compute_prefix_tbl(pattern, len, kmp->prefix_tbl, flags);
kmp->pattern = (u8 *) kmp->prefix_tbl + prefix_tbl_len;
if (flags & TS_IGNORECASE)
for (i = 0; i < len; i++)
kmp->pattern[i] = toupper(((u8 *)pattern)[i]);
else
memcpy(kmp->pattern, pattern, len);
return conf;
}
static void *kmp_get_pattern(struct ts_config *conf)
{
struct ts_kmp *kmp = ts_config_priv(conf);
return kmp->pattern;
}
static unsigned int kmp_get_pattern_len(struct ts_config *conf)
{
struct ts_kmp *kmp = ts_config_priv(conf);
return kmp->pattern_len;
}
static struct ts_ops kmp_ops = {
.name = "kmp",
.find = kmp_find,
.init = kmp_init,
.get_pattern = kmp_get_pattern,
.get_pattern_len = kmp_get_pattern_len,
.owner = THIS_MODULE,
.list = LIST_HEAD_INIT(kmp_ops.list)
};
static int __init init_kmp(void)
{
return textsearch_register(&kmp_ops);
}
static void __exit exit_kmp(void)
{
textsearch_unregister(&kmp_ops);
}
MODULE_LICENSE("GPL");
module_init(init_kmp);
module_exit(exit_kmp);
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