From: Ingo Molnar <mingo@elte.hu>
To: linux-kernel@vger.kernel.org, Linus Torvalds <torvalds@osdl.org>,
Andrew Morton <akpm@osdl.org>
Cc: Arjan van de Ven <arjanv@infradead.org>,
Steven Rostedt <rostedt@goodmis.org>,
Alan Cox <alan@lxorguk.ukuu.org.uk>,
Christoph Hellwig <hch@infradead.org>, Andi Kleen <ak@suse.de>,
David Howells <dhowells@redhat.com>,
Alexander Viro <viro@ftp.linux.org.uk>,
Oleg Nesterov <oleg@tv-sign.ru>, Paul Jackson <pj@sgi.com>
Subject: [patch 07/15] Generic Mutex Subsystem, mutex-debug-more.patch
Date: Mon, 19 Dec 2005 02:38:07 +0100 [thread overview]
Message-ID: <20051219013807.GC28038@elte.hu> (raw)
more mutex debugging: check for held locks during memory freeing,
task exit, enable sysrq printouts, etc.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
----
arch/i386/mm/pageattr.c | 3 +++
drivers/char/sysrq.c | 19 +++++++++++++++++++
include/linux/mm.h | 11 +++++++++++
include/linux/sched.h | 11 +++++++++++
kernel/exit.c | 4 ++++
kernel/sched.c | 1 +
lib/spinlock_debug.c | 18 ++++++++++--------
mm/page_alloc.c | 3 +++
mm/slab.c | 5 +++++
9 files changed, 67 insertions(+), 8 deletions(-)
Index: linux/arch/i386/mm/pageattr.c
===================================================================
--- linux.orig/arch/i386/mm/pageattr.c
+++ linux/arch/i386/mm/pageattr.c
@@ -207,6 +207,9 @@ void kernel_map_pages(struct page *page,
{
if (PageHighMem(page))
return;
+ if (!enable)
+ check_no_locks_freed(page_address(page), page_address(page+numpages));
+
/* the return value is ignored - the calls cannot fail,
* large pages are disabled at boot time.
*/
Index: linux/drivers/char/sysrq.c
===================================================================
--- linux.orig/drivers/char/sysrq.c
+++ linux/drivers/char/sysrq.c
@@ -153,6 +153,21 @@ static struct sysrq_key_op sysrq_mountro
/* END SYNC SYSRQ HANDLERS BLOCK */
+#ifdef CONFIG_DEBUG_MUTEXESS
+
+static void
+sysrq_handle_showlocks(int key, struct pt_regs *pt_regs, struct tty_struct *tty)
+{
+ show_all_locks();
+}
+
+static struct sysrq_key_op sysrq_showlocks_op = {
+ .handler = sysrq_handle_showlocks,
+ .help_msg = "show-all-locks(D)",
+ .action_msg = "Show Locks Held",
+};
+
+#endif
/* SHOW SYSRQ HANDLERS BLOCK */
@@ -294,7 +309,11 @@ static struct sysrq_key_op *sysrq_key_ta
#else
/* c */ NULL,
#endif
+#ifdef CONFIG_DEBUG_MUTEXESS
+/* d */ &sysrq_showlocks_op,
+#else
/* d */ NULL,
+#endif
/* e */ &sysrq_term_op,
/* f */ &sysrq_moom_op,
/* g */ NULL,
Index: linux/include/linux/mm.h
===================================================================
--- linux.orig/include/linux/mm.h
+++ linux/include/linux/mm.h
@@ -973,10 +973,21 @@ static inline void vm_stat_account(struc
}
#endif /* CONFIG_PROC_FS */
+#ifdef CONFIG_DEBUG_MUTEXESS
+ extern int check_no_locks_freed(const void *from, const void *to);
+#else
+ static inline int check_no_locks_freed(const void *from, const void *to)
+ {
+ return 0;
+ }
+#endif
+
#ifndef CONFIG_DEBUG_PAGEALLOC
static inline void
kernel_map_pages(struct page *page, int numpages, int enable)
{
+ if (!PageHighMem(page) && !enable)
+ check_no_locks_freed(page_address(page), page_address(page+numpages));
}
#endif
Index: linux/include/linux/sched.h
===================================================================
--- linux.orig/include/linux/sched.h
+++ linux/include/linux/sched.h
@@ -186,6 +186,17 @@ extern cpumask_t nohz_cpu_mask;
extern void show_state(void);
extern void show_regs(struct pt_regs *);
+#ifdef CONFIG_DEBUG_MUTEXESS
+ extern void deadlock_trace_off(void);
+ extern void show_held_locks(struct task_struct *filter);
+ extern void check_no_held_locks(struct task_struct *task);
+ extern void show_all_locks(void);
+#else
+# define deadlock_trace_off() do { } while (0)
+# define show_held_locks(p) do { } while (0)
+# define check_no_held_locks(task) do { } while (0)
+# define show_all_locks() do { } while (0)
+#endif
/*
* TASK is a pointer to the task whose backtrace we want to see (or NULL for current
Index: linux/kernel/exit.c
===================================================================
--- linux.orig/kernel/exit.c
+++ linux/kernel/exit.c
@@ -870,6 +870,10 @@ fastcall NORET_TYPE void do_exit(long co
mpol_free(tsk->mempolicy);
tsk->mempolicy = NULL;
#endif
+ /*
+ * If DEBUG_MUTEXESS is on, make sure we are holding no locks:
+ */
+ check_no_held_locks(tsk);
/* PF_DEAD causes final put_task_struct after we schedule. */
preempt_disable();
Index: linux/kernel/sched.c
===================================================================
--- linux.orig/kernel/sched.c
+++ linux/kernel/sched.c
@@ -4379,6 +4379,7 @@ void show_state(void)
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
+ show_all_locks();
}
/**
Index: linux/lib/spinlock_debug.c
===================================================================
--- linux.orig/lib/spinlock_debug.c
+++ linux/lib/spinlock_debug.c
@@ -20,7 +20,8 @@ static void spin_bug(spinlock_t *lock, c
if (lock->owner && lock->owner != SPINLOCK_OWNER_INIT)
owner = lock->owner;
printk("BUG: spinlock %s on CPU#%d, %s/%d\n",
- msg, smp_processor_id(), current->comm, current->pid);
+ msg, raw_smp_processor_id(),
+ current->comm, current->pid);
printk(" lock: %p, .magic: %08x, .owner: %s/%d, .owner_cpu: %d\n",
lock, lock->magic,
owner ? owner->comm : "<none>",
@@ -78,8 +79,8 @@ static void __spin_lock_debug(spinlock_t
if (print_once) {
print_once = 0;
printk("BUG: spinlock lockup on CPU#%d, %s/%d, %p\n",
- smp_processor_id(), current->comm, current->pid,
- lock);
+ raw_smp_processor_id(), current->comm,
+ current->pid, lock);
dump_stack();
}
}
@@ -120,7 +121,8 @@ static void rwlock_bug(rwlock_t *lock, c
if (xchg(&print_once, 0)) {
printk("BUG: rwlock %s on CPU#%d, %s/%d, %p\n", msg,
- smp_processor_id(), current->comm, current->pid, lock);
+ raw_smp_processor_id(), current->comm,
+ current->pid, lock);
dump_stack();
#ifdef CONFIG_SMP
/*
@@ -148,8 +150,8 @@ static void __read_lock_debug(rwlock_t *
if (print_once) {
print_once = 0;
printk("BUG: read-lock lockup on CPU#%d, %s/%d, %p\n",
- smp_processor_id(), current->comm, current->pid,
- lock);
+ raw_smp_processor_id(), current->comm,
+ current->pid, lock);
dump_stack();
}
}
@@ -220,8 +222,8 @@ static void __write_lock_debug(rwlock_t
if (print_once) {
print_once = 0;
printk("BUG: write-lock lockup on CPU#%d, %s/%d, %p\n",
- smp_processor_id(), current->comm, current->pid,
- lock);
+ raw_smp_processor_id(), current->comm,
+ current->pid, lock);
dump_stack();
}
}
Index: linux/mm/page_alloc.c
===================================================================
--- linux.orig/mm/page_alloc.c
+++ linux/mm/page_alloc.c
@@ -400,6 +400,9 @@ void __free_pages_ok(struct page *page,
int reserved = 0;
arch_free_page(page, order);
+ if (!PageHighMem(page))
+ check_no_locks_freed(page_address(page),
+ page_address(page+(1<<order)));
#ifndef CONFIG_MMU
if (order > 0)
Index: linux/mm/slab.c
===================================================================
--- linux.orig/mm/slab.c
+++ linux/mm/slab.c
@@ -3038,6 +3038,11 @@ void kfree(const void *objp)
local_irq_save(flags);
kfree_debugcheck(objp);
c = page_get_cache(virt_to_page(objp));
+#ifdef CONFIG_DEADLOCK_DETECT
+ if (check_no_locks_freed(objp, objp+cache_size(c)))
+ printk("slab %s[%p] (%d), obj: %p\n",
+ c->name, c, c->objsize, objp);
+#endif
__cache_free(c, (void*)objp);
local_irq_restore(flags);
}
next reply other threads:[~2005-12-19 1:38 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-12-19 1:38 Ingo Molnar [this message]
2005-12-19 14:00 ` [patch 07/15] Generic Mutex Subsystem, mutex-debug-more.patch Steven Rostedt
2005-12-19 17:00 ` Ingo Molnar
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20051219013807.GC28038@elte.hu \
--to=mingo@elte.hu \
--cc=ak@suse.de \
--cc=akpm@osdl.org \
--cc=alan@lxorguk.ukuu.org.uk \
--cc=arjanv@infradead.org \
--cc=dhowells@redhat.com \
--cc=hch@infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=oleg@tv-sign.ru \
--cc=pj@sgi.com \
--cc=rostedt@goodmis.org \
--cc=torvalds@osdl.org \
--cc=viro@ftp.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).