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
......@@ -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.
*/
......
......@@ -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,
......
......@@ -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
......
......@@ -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();
......
......@@ -4386,6 +4386,7 @@ void show_state(void)
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
mutex_debug_show_all_locks();
}
/**
......
......@@ -415,6 +415,9 @@ static void __free_pages_ok(struct page *page, unsigned int order)
int reserved = 0;
arch_free_page(page, order);
if (!PageHighMem(page))
mutex_debug_check_no_locks_freed(page_address(page),
page_address(page+(1<<order)));
#ifndef CONFIG_MMU
for (i = 1 ; i < (1 << order) ; ++i)
......
......@@ -3071,6 +3071,7 @@ void kfree(const void *objp)
local_irq_save(flags);
kfree_debugcheck(objp);
c = page_get_cache(virt_to_page(objp));
mutex_debug_check_no_locks_freed(objp, objp+obj_reallen(c));
__cache_free(c, (void *)objp);
local_irq_restore(flags);
}
......
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