Hi Tony, Alan,
as it turns out there is the SLAB_ATOMIC flag which can be
used to call the slab cache in a legal way if the task isn't
in TASK_RUNNING.
The attached boobytrap2 patch adds checks for that situation
and won't barf when something like that happens. This should
reduce the number of false positives and the number of error
messages (making it more convinient for people to test the patches).
regards,
Rik
-- The Internet is not a network of computers. It is a network of people. That is its real strength.--- linux-2.2.15pre5/mm/vmscan.c.orig Fri Jan 28 00:13:18 2000 +++ linux-2.2.15pre5/mm/vmscan.c Fri Jan 28 01:46:02 2000 @@ -497,8 +497,11 @@ { if (!do_try_to_free_pages(GFP_KSWAPD)) break; - if (tsk->need_resched) + if (tsk->need_resched) { + if (nr_free_pages > freepages.low) + break; schedule(); + } } run_task_queue(&tq_disk); interruptible_sleep_on_timeout(&kswapd_wait, HZ); --- linux-2.2.15pre5/mm/memory.c.orig Fri Jan 28 00:16:30 2000 +++ linux-2.2.15pre5/mm/memory.c Fri Jan 28 01:45:40 2000 @@ -611,6 +611,12 @@ pte_t pte; unsigned long old_page, new_page; struct page * page_map; + + /* booby trap */ + if (current->state != TASK_RUNNING) { + printk("do_wp_page called by non-running (%d) task from %p!\n", + current->state, __builtin_return_address(0)); + } pte = *page_table; new_page = __get_free_page(GFP_USER); @@ -806,6 +812,13 @@ static int do_anonymous_page(struct task_struct * tsk, struct vm_area_struct * vma, pte_t *page_table, int write_access, unsigned long addr) { pte_t entry = pte_wrprotect(mk_pte(ZERO_PAGE(addr), vma->vm_page_prot)); + + /* booby trap */ + if (current->state != TASK_RUNNING) { + printk("do_anonymous_page called by non-running (%d) task from %p!\n", + current->state, __builtin_return_address(0)); + } + if (write_access) { unsigned long page = __get_free_page(GFP_USER); if (!page) @@ -932,6 +945,12 @@ pte_t * pte; int ret; + /* booby trap */ + if (current->state != TASK_RUNNING) { + printk("handle_mm_fault called by non-running (%d) task from %p!\n", + current->state, __builtin_return_address(0)); + } + pgd = pgd_offset(vma->vm_mm, address); pmd = pmd_alloc(pgd, address); if (!pmd) --- linux-2.2.15pre5/mm/slab.c.orig Fri Jan 28 00:16:50 2000 +++ linux-2.2.15pre5/mm/slab.c Fri Jan 28 15:34:25 2000 @@ -687,6 +687,12 @@ size_t left_over; size_t align; + /* booby trap */ + if (current->state != TASK_RUNNING && flags != SLAB_ATOMIC) { + printk("kmem_cache_create called by non-running (%d) task from %p!\n", + current->state, __builtin_return_address(0)); + } + /* Sanity checks... */ #if SLAB_MGMT_CHECKS if (!name) { @@ -1589,6 +1595,12 @@ void * kmem_cache_alloc(kmem_cache_t *cachep, int flags) { + /* booby trap */ + if (current->state != TASK_RUNNING && flags != SLAB_ATOMIC) { + printk("kmem_cache_alloc called by non-running (%d) task from %p!\n", + current->state, __builtin_return_address(0)); + } + return __kmem_cache_alloc(cachep, flags); }
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This archive was generated by hypermail 2b29 : Mon Jan 31 2000 - 21:00:21 EST