* 2008-2009 Alexey Gerenkov <a.gerenkov@samsung.com> User-Space
* Probes initial implementation; Support x86/ARM/MIPS for both user and kernel spaces.
* 2010 Ekaterina Gorelkina <e.gorelkina@samsung.com>: redesign module for separating core and arch parts
- * 2012 Vyacheslav Cherkashin <v.cherkashin@samsung.com> new memory allocator for slots
+ * 2012-2013 Vyacheslav Cherkashin <v.cherkashin@samsung.com> new memory allocator for slots
*/
#include "dbi_insn_slots.h"
-#include "dbi_kdebug.h"
-
-#include <linux/hash.h>
-#include <linux/mman.h>
-#include <linux/hugetlb.h>
-
+#include <linux/module.h>
+#include <linux/rculist.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
-#include <linux/module.h>
-
-
-extern unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
- unsigned long len, unsigned long prot,
- unsigned long flags, unsigned long pgoff);
struct chunk {
unsigned long *data;
unsigned long *index;
};
-struct kprobe_insn_page
+struct fixed_alloc
{
struct hlist_node hlist;
-
struct chunk chunk;
- struct task_struct *task;
};
static void chunk_init(struct chunk *chunk, void *data, size_t size, size_t size_block)
return (chunk->count_available == chunk->size);
}
-static unsigned long alloc_user_pages(struct task_struct *task, unsigned long len, unsigned long prot, unsigned long flags, int atomic)
-{
- unsigned long ret = 0;
- struct task_struct *otask = current;
- struct mm_struct *mm;
-
- mm = atomic ? task->active_mm : get_task_mm (task);
- if (mm) {
- if (!atomic) {
- if (!down_write_trylock(&mm->mmap_sem)) {
- rcu_read_lock();
-
- up_read(&mm->mmap_sem);
- down_write(&mm->mmap_sem);
-
- rcu_read_unlock();
- }
- }
- // FIXME: its seems to be bad decision to replace 'current' pointer temporarily
- current_thread_info()->task = task;
- ret = do_mmap_pgoff(NULL, 0, len, prot, flags, 0);
- current_thread_info()->task = otask;
- if (!atomic) {
- downgrade_write (&mm->mmap_sem);
- mmput(mm);
- }
- } else {
- printk("proc %d has no mm", task->tgid);
- }
-
- return ret;
-}
-
-static void *page_new(struct task_struct *task, int atomic)
-{
- if (task) {
- return (void *)alloc_user_pages(task, PAGE_SIZE,
- PROT_EXEC|PROT_READ|PROT_WRITE,
- MAP_ANONYMOUS|MAP_PRIVATE/*MAP_SHARED*/, atomic);
- } else {
- return kmalloc(PAGE_SIZE, GFP_ATOMIC);
- }
-}
-
-static void page_free(void *data, struct task_struct *task)
-{
- if (task) {
- //E. G.: This code provides kernel dump because of rescheduling while atomic.
- //As workaround, this code was commented. In this case we will have memory leaks
- //for instrumented process, but instrumentation process should functionate correctly.
- //Planned that good solution for this problem will be done during redesigning KProbe
- //for improving supportability and performance.
-#if 0
- mm = get_task_mm (task);
- if (mm) {
- down_write (&mm->mmap_sem);
- do_munmap(mm, (unsigned long)(data), PAGE_SIZE);
- up_write (&mm->mmap_sem);
- mmput(mm);
- }
-#endif
- // FIXME: implement the removal of memory for task
- } else {
- kfree(data);
- }
-}
-
-static inline size_t slot_size(struct task_struct *task)
-{
- if (task) {
- return UPROBES_TRAMP_LEN;
- } else {
- return KPROBES_TRAMP_LEN;
- }
-}
-
-static struct kprobe_insn_page *kip_new(struct task_struct *task, int atomic)
+static struct fixed_alloc *create_fixed_alloc(struct slot_manager *sm)
{
void *data;
- struct kprobe_insn_page *kip;
+ struct fixed_alloc *fa;
- kip = kmalloc(sizeof(*kip), GFP_ATOMIC);
- if (kip == NULL) {
+ fa = kmalloc(sizeof(*fa), GFP_ATOMIC);
+ if (fa == NULL) {
return NULL;
}
- data = page_new(task, atomic);
+ data = sm->alloc(sm);
if(data == NULL) {
- kfree(kip);
+ kfree(fa);
return NULL;
}
- chunk_init(&kip->chunk, data, PAGE_SIZE/sizeof(unsigned long), slot_size(task));
- kip->task = task;
+ chunk_init(&fa->chunk, data, PAGE_SIZE/sizeof(unsigned long), sm->slot_size);
- return kip;
+ return fa;
}
-static void kip_free(struct kprobe_insn_page * kip)
+static void free_fixed_alloc(struct slot_manager *sm, struct fixed_alloc *fa)
{
- chunk_uninit(&kip->chunk);
- page_free(kip->chunk.data, kip->task);
- kfree(kip);
+ chunk_uninit(&fa->chunk);
+ sm->free(sm, fa->chunk.data);
+ kfree(fa);
}
-/**
- * get_us_insn_slot() - Find a slot on an executable page for an instruction.
- * We allocate an executable page if there's no room on existing ones.
- */
-kprobe_opcode_t *get_insn_slot(struct task_struct *task, struct hlist_head *page_list, int atomic)
+
+void *alloc_insn_slot(struct slot_manager *sm)
{
- kprobe_opcode_t * free_slot;
- struct kprobe_insn_page *kip;
+ void *free_slot;
+ struct fixed_alloc *fa;
struct hlist_node *pos;
- hlist_for_each_entry_rcu(kip, pos, page_list, hlist) {
- if (!task || (kip->task->tgid == task->tgid)) {
- free_slot = chunk_allocate(&kip->chunk, slot_size(task));
- if (free_slot == NULL) {
- break;
- }
-
+ hlist_for_each_entry_rcu(fa, pos, &sm->page_list, hlist) {
+ free_slot = chunk_allocate(&fa->chunk, sm->slot_size);
+ if (free_slot)
return free_slot;
- }
}
- kip = kip_new(task, atomic);
- if(kip == NULL)
+ fa = create_fixed_alloc(sm);
+ if(fa == NULL)
return NULL;
- INIT_HLIST_NODE (&kip->hlist);
- hlist_add_head_rcu(&kip->hlist, page_list);
+ INIT_HLIST_NODE(&fa->hlist);
+ hlist_add_head_rcu(&fa->hlist, &sm->page_list);
- return chunk_allocate(&kip->chunk, slot_size(task));
+ return chunk_allocate(&fa->chunk, sm->slot_size);
}
-EXPORT_SYMBOL_GPL(get_insn_slot);
+EXPORT_SYMBOL_GPL(alloc_insn_slot);
-void free_insn_slot(struct hlist_head *page_list, struct task_struct *task, kprobe_opcode_t *slot)
+void free_insn_slot(struct slot_manager *sm, void *slot)
{
- struct kprobe_insn_page *kip;
+ struct fixed_alloc *fa;
struct hlist_node *pos;
- hlist_for_each_entry_rcu(kip, pos, page_list, hlist) {
- if (!(!task || (kip->task->tgid == task->tgid)))
- continue;
-
- if (!chunk_check_ptr(&kip->chunk, slot, PAGE_SIZE))
+ hlist_for_each_entry_rcu(fa, pos, &sm->page_list, hlist) {
+ if (!chunk_check_ptr(&fa->chunk, slot, PAGE_SIZE))
continue;
- chunk_deallocate(&kip->chunk, slot, slot_size(task));
+ chunk_deallocate(&fa->chunk, slot, sm->slot_size);
- if (chunk_free(&kip->chunk)) {
- hlist_del_rcu(&kip->hlist);
- kip_free(kip);
+ if (chunk_free(&fa->chunk)) {
+ hlist_del_rcu(&fa->hlist);
+ free_fixed_alloc(sm, fa);
}
return;
projects / kernel / swap-modules.git / blobdiff