Module: xenomai-3
Branch: stable-3.0.x
Commit: 5036abbe902454f4402a1bc11e7687f4ed39116b
URL:
http://git.xenomai.org/?p=xenomai-3.git;a=commit;h=5036abbe902454f4402a1bc11e7687f4ed39116b
Author: Jan Kiszka <jan.kis...@siemens.com>
Date: Thu Oct 12 09:46:41 2017 +0200
cobalt/debug: Fix locking
None of these functions are called over interrupt context. Leaving the
critical sections interruptible can cause premature/double-unlock
scenarios and bug reports such as
[Xenomai] lock ffffffff81c56000 already unlocked on CPU #1
last owner = kernel/xenomai/debug.c:74 (hash_symbol(), CPU #1)
000000000000002f ffff88007dc8bb10 ffffffff8118ae8f ffffffff00000001
0000000000000021 ffff88007f897fde ffff88007dc8bb50 ffffffff8118b266
00000000000000f1 ffff88007dc8bd68 0000000000000006 ffff88007dc8bd40
Call Trace:
[<ffffffff8118ae8f>] xnlock_dbg_release+0xdf/0xf0
[<ffffffff8118b266>] hash_symbol+0x236/0x2d0
[<ffffffff8118b668>] xndebug_trace_relax+0x118/0x450
[<ffffffff811b8d50>] ? CoBaLt32emu_mmap+0xf0/0xf0
[<ffffffff811b8dd7>] CoBaLt32emu_backtrace+0x87/0xb0
[<ffffffff8100def6>] ? fpu__clear+0xd6/0x160
[<ffffffff817b3691>] ? _raw_spin_unlock_irq+0x11/0x30
[<ffffffff811ab1cc>] ipipe_syscall_hook+0x11c/0x3a0
[<ffffffff8113d9bf>] __ipipe_notify_syscall+0xbf/0x180
[<ffffffff810cd019>] ? __set_current_blocked+0x49/0x50
[<ffffffff8113daab>] ipipe_handle_syscall+0x2b/0xb0
[<ffffffff81001c9d>] do_fast_syscall_32+0xbd/0x220
[<ffffffff817b64e2>] sysenter_flags_fixed+0x8/0x12
Signed-off-by: Jan Kiszka <jan.kis...@siemens.com>
---
kernel/cobalt/debug.c | 28 ++++++++++++++++------------
1 file changed, 16 insertions(+), 12 deletions(-)
diff --git a/kernel/cobalt/debug.c b/kernel/cobalt/debug.c
index 312f43a..2c5dee1 100644
--- a/kernel/cobalt/debug.c
+++ b/kernel/cobalt/debug.c
@@ -64,14 +64,15 @@ DEFINE_PRIVATE_XNLOCK(symbol_lock);
static const char *hash_symbol(const char *symbol)
{
struct hashed_symbol *p, **h;
- const char *s;
+ const char *str;
size_t len;
u32 hash;
+ spl_t s;
len = strlen(symbol);
hash = jhash(symbol, len, 0);
- xnlock_get(&symbol_lock);
+ xnlock_get_irqsave(&symbol_lock, s);
h = &symbol_jhash[hash & (SYMBOL_HSLOTS - 1)];
p = *h;
@@ -85,7 +86,7 @@ static const char *hash_symbol(const char *symbol)
p = xnheap_alloc(&memory_pool, sizeof(*p) + len + 1);
if (p == NULL) {
- s = NULL;
+ str = NULL;
goto out;
}
@@ -93,11 +94,11 @@ static const char *hash_symbol(const char *symbol)
p->next = *h;
*h = p;
done:
- s = p->symbol;
+ str = p->symbol;
out:
- xnlock_put(&symbol_lock);
+ xnlock_put_irqrestore(&symbol_lock, s);
- return s;
+ return str;
}
/*
@@ -214,6 +215,7 @@ void xndebug_trace_relax(int nr, unsigned long *backtrace,
int n, depth;
char *tmp;
u32 hash;
+ spl_t s;
thread = xnthread_current();
if (thread == NULL)
@@ -285,7 +287,7 @@ void xndebug_trace_relax(int nr, unsigned long *backtrace,
strcpy(spot.thread, thread->name);
hash = jhash2((u32 *)&spot, sizeof(spot) / sizeof(u32), 0);
- xnlock_get(&relax_lock);
+ xnlock_get_irqsave(&relax_lock, s);
h = &relax_jhash[hash & (RELAX_HSLOTS - 1)];
p = *h;
@@ -326,7 +328,7 @@ void xndebug_trace_relax(int nr, unsigned long *backtrace,
out:
relax_overall++;
- xnlock_put(&relax_lock);
+ xnlock_put_irqrestore(&relax_lock, s);
}
static DEFINE_VFILE_HOSTLOCK(relax_mutex);
@@ -343,6 +345,7 @@ static void *relax_vfile_begin(struct
xnvfile_regular_iterator *it)
{
struct relax_vfile_priv *priv = xnvfile_iterator_priv(it);
struct relax_record *p;
+ spl_t s;
int n;
/*
@@ -352,7 +355,7 @@ static void *relax_vfile_begin(struct
xnvfile_regular_iterator *it)
* holds the relax_mutex lock for us, so that we can't race
* with ->store().
*/
- xnlock_get(&relax_lock);
+ xnlock_get_irqsave(&relax_lock, s);
if (relax_queued == 0 || it->pos > relax_queued) {
xnlock_put(&relax_lock);
@@ -362,7 +365,7 @@ static void *relax_vfile_begin(struct
xnvfile_regular_iterator *it)
priv->queued = relax_queued;
priv->head = relax_record_list;
- xnlock_put(&relax_lock);
+ xnlock_put_irqrestore(&relax_lock, s);
if (it->pos == 0) {
priv->curr = NULL;
@@ -447,19 +450,20 @@ static int relax_vfile_show(struct
xnvfile_regular_iterator *it, void *data)
static ssize_t relax_vfile_store(struct xnvfile_input *input)
{
struct relax_record *p, *np;
+ spl_t s;
/*
* Flush out all records. Races with ->show() are prevented
* using the relax_mutex lock. The vfile layer takes care of
* this internally.
*/
- xnlock_get(&relax_lock);
+ xnlock_get_irqsave(&relax_lock, s);
p = relax_record_list;
relax_record_list = NULL;
relax_overall = 0;
relax_queued = 0;
memset(relax_jhash, 0, sizeof(relax_jhash));
- xnlock_put(&relax_lock);
+ xnlock_put_irqrestore(&relax_lock, s);
while (p) {
np = p->r_next;
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