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Commit de5097c2 authored by Ingo Molnar's avatar Ingo Molnar Committed by Ingo Molnar
Browse files

[PATCH] mutex subsystem, more debugging code 



more mutex debugging: check for held locks during memory freeing,
task exit, enable sysrq printouts, etc.

Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarArjan van de Ven <arjan@infradead.org>
parent 408894ee

arch/i386/mm/pageattr.c

+4 −0
Original line number Diff line number Diff line
@@ -222,6 +222,10 @@ void kernel_map_pages(struct page *page, int numpages, int enable) 
{

	if (PageHighMem(page))

		return;

	if (!enable)

		mutex_debug_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.

	 */

drivers/char/sysrq.c

+19 −0
Original line number Diff line number Diff line
@@ -153,6 +153,21 @@ static struct sysrq_key_op sysrq_mountro_op = { 


/* END SYNC SYSRQ HANDLERS BLOCK */



#ifdef CONFIG_DEBUG_MUTEXES



static void

sysrq_handle_showlocks(int key, struct pt_regs *pt_regs, struct tty_struct *tty)

{

	mutex_debug_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_table[SYSRQ_KEY_TABLE_LENGTH] = { 
#else

/* c */	NULL,

#endif

#ifdef CONFIG_DEBUG_MUTEXES

/* d */ &sysrq_showlocks_op,

#else

/* d */ NULL,

#endif

/* e */	&sysrq_term_op,

/* f */	&sysrq_moom_op,

/* g */	NULL,

include/linux/mm.h

+4 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include <linux/rbtree.h>

#include <linux/prio_tree.h>

#include <linux/fs.h>

#include <linux/mutex.h>



struct mempolicy;

struct anon_vma;
@@ -1024,6 +1025,9 @@ static inline void vm_stat_account(struct mm_struct *mm, 
static inline void

kernel_map_pages(struct page *page, int numpages, int enable)

{

	if (!PageHighMem(page) && !enable)

		mutex_debug_check_no_locks_freed(page_address(page),

						 page_address(page + numpages));

}

#endif

kernel/exit.c

+5 −0
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ 
#include <linux/syscalls.h>

#include <linux/signal.h>

#include <linux/cn_proc.h>

#include <linux/mutex.h>



#include <asm/uaccess.h>

#include <asm/unistd.h>
@@ -869,6 +870,10 @@ fastcall NORET_TYPE void do_exit(long code) 
	mpol_free(tsk->mempolicy);

	tsk->mempolicy = NULL;

#endif

	/*

	 * If DEBUG_MUTEXES is on, make sure we are holding no locks:

	 */

	mutex_debug_check_no_locks_held(tsk);



	/* PF_DEAD causes final put_task_struct after we schedule. */

	preempt_disable();

kernel/sched.c

+1 −0
Original line number Diff line number Diff line
@@ -4386,6 +4386,7 @@ void show_state(void) 
	} while_each_thread(g, p);



	read_unlock(&tasklist_lock);

	mutex_debug_show_all_locks();

}



/**