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use irqsave page directory lock to avoid deadlocks

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This commit is contained in:
Stefan Lankes 2012-09-10 13:41:00 +02:00
parent 7aea508931
commit e1c3ddbc8d
3 changed files with 48 additions and 53 deletions
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95
arch/x86/mm/page32.c
View file

@ -172,7 +172,7 @@ int create_pgd(task_t* task, int copy)
task->pgd = pgd;
if (copy) {
spinlock_lock(&curr_task->pgd_lock);
spinlock_irqsave_lock(&curr_task->pgd_lock);
for (i=KERNEL_SPACE/(1024*PAGE_SIZE); i<1024; i++) {
if (!(curr_task->pgd->entries[i]))
@ -187,7 +187,7 @@ int create_pgd(task_t* task, int copy)
}
}
spinlock_unlock(&curr_task->pgd_lock);
spinlock_irqsave_unlock(&curr_task->pgd_lock);
}
return counter;
@ -206,7 +206,7 @@ int drop_pgd(void)
if (BUILTIN_EXPECT(pgd == &boot_pgd, 0))
return -EINVAL;
spinlock_lock(&task->pgd_lock);
spinlock_irqsave_lock(&task->pgd_lock);
for(i=0; i<PGT_ENTRIES; i++) {
if (pgd->entries[i] & PG_USER) {
@ -220,7 +220,7 @@ int drop_pgd(void)
task->pgd = NULL;
spinlock_unlock(&task->pgd_lock);
spinlock_irqsave_unlock(&task->pgd_lock);
return 0;
}
@ -238,7 +238,7 @@ size_t virt_to_phys(size_t viraddr)
if (BUILTIN_EXPECT(!task || !task->pgd, 0))
return 0;
spinlock_lock(&task->pgd_lock);
spinlock_irqsave_lock(&task->pgd_lock);
index1 = viraddr >> 22;
index2 = (viraddr >> 12) & 0x3FF;
@ -255,7 +255,7 @@ size_t virt_to_phys(size_t viraddr)
out:
//kprintf("vir %p to phy %p\n", viraddr, ret);
spinlock_unlock(&task->pgd_lock);
spinlock_irqsave_unlock(&task->pgd_lock);
return ret;
}
@ -263,11 +263,9 @@ out:
size_t map_region(size_t viraddr, size_t phyaddr, uint32_t npages, uint32_t flags)
{
task_t* task = per_core(current_task);
spinlock_t* pgd_lock;
page_table_t* pgt;
size_t index, i;
size_t ret;
uint32_t irqflags;
if (BUILTIN_EXPECT(!task || !task->pgd, 0))
return 0;
@ -276,22 +274,16 @@ size_t map_region(size_t viraddr, size_t phyaddr, uint32_t npages, uint32_t flag
return 0;
if (flags & MAP_KERNEL_SPACE)
pgd_lock = &kslock;
spinlock_lock(&kslock);
else
pgd_lock = &task->pgd_lock;
// avoid interrupts because the IRQ handler is able to call map_region
irqflags = irq_nested_disable();
spinlock_lock(pgd_lock);
spinlock_irqsave_lock(&task->pgd_lock);
if (!viraddr) {
viraddr = vm_alloc(npages, flags);
if (BUILTIN_EXPECT(!viraddr, 0)) {
spinlock_unlock(pgd_lock);
irq_nested_enable(irqflags);
kputs("map_adress: found no valid virtual address\n");
return 0;
ret = 0;
goto out;
}
}
@ -305,10 +297,9 @@ size_t map_region(size_t viraddr, size_t phyaddr, uint32_t npages, uint32_t flag
pgt = (page_table_t*) get_pages(1);
if (BUILTIN_EXPECT(!pgt, 0)) {
spinlock_unlock(pgd_lock);
irq_nested_enable(irqflags);
kputs("map_address: out of memory\n");
return 0;
ret = 0;
goto out;
}
// set the new page table into the directory
@ -326,10 +317,9 @@ size_t map_region(size_t viraddr, size_t phyaddr, uint32_t npages, uint32_t flag
pgt_container = (page_table_t*) (task->pgd->entries[(KERNEL_SPACE - PAGE_SIZE) >> 22] & PAGE_MASK);
if (BUILTIN_EXPECT(!pgt_container, 0)) {
spinlock_unlock(pgd_lock);
irq_nested_enable(irqflags);
kputs("map_address: internal error\n");
return 0;
ret = 0;
goto out;
}
// map the new table into the address space of the kernel space
@ -348,10 +338,9 @@ size_t map_region(size_t viraddr, size_t phyaddr, uint32_t npages, uint32_t flag
index = (viraddr >> 12) & 0x3FF;
if (pgt->entries[index] && !(flags & MAP_REMAP)) {
spinlock_unlock(pgd_lock);
irq_nested_enable(irqflags);
kprintf("0x%x is already mapped\n", viraddr);
return 0;
ret = 0;
goto out;
}
if (flags & MAP_USER_SPACE)
@ -389,8 +378,11 @@ size_t map_region(size_t viraddr, size_t phyaddr, uint32_t npages, uint32_t flag
tlb_flush_one_page(viraddr);
}
spinlock_unlock(pgd_lock);
irq_nested_enable(irqflags);
out:
if (flags & MAP_KERNEL_SPACE)
spinlock_unlock(&kslock);
else
spinlock_irqsave_unlock(&task->pgd_lock);
return ret;
}
@ -411,7 +403,7 @@ int change_page_permissions(size_t start, size_t end, uint32_t flags)
if (BUILTIN_EXPECT(!pgd, 0))
return -EINVAL;
spinlock_lock(&task->pgd_lock);
spinlock_irqsave_lock(&task->pgd_lock);
while (viraddr < end)
{
@ -456,7 +448,7 @@ int change_page_permissions(size_t start, size_t end, uint32_t flags)
}
}
spinlock_unlock(&task->pgd_lock);
spinlock_irqsave_unlock(&task->pgd_lock);
return 0;
}
@ -469,7 +461,6 @@ int change_page_permissions(size_t start, size_t end, uint32_t flags)
size_t vm_alloc(uint32_t npages, uint32_t flags)
{
task_t* task = per_core(current_task);
spinlock_t* pgd_lock;
uint32_t index1, index2, j;
size_t viraddr, i, ret = 0;
size_t start, end;
@ -479,11 +470,9 @@ size_t vm_alloc(uint32_t npages, uint32_t flags)
return 0;
if (flags & MAP_KERNEL_SPACE) {
pgd_lock = &kslock;
start = (((size_t) &kernel_end) + PAGE_SIZE) & PAGE_MASK;
end = (KERNEL_SPACE - 2*PAGE_SIZE) & PAGE_MASK; // we need 1 PAGE for our PGTs
} else {
pgd_lock = &task->pgd_lock;
start = KERNEL_SPACE & PAGE_MASK;
end = PAGE_MASK;
}
@ -491,7 +480,10 @@ size_t vm_alloc(uint32_t npages, uint32_t flags)
if (BUILTIN_EXPECT(!npages, 0))
return 0;
spinlock_lock(pgd_lock);
if (flags & MAP_KERNEL_SPACE)
spinlock_lock(&kslock);
else
spinlock_irqsave_lock(&task->pgd_lock);
viraddr = i = start;
j = 0;
@ -514,7 +506,10 @@ size_t vm_alloc(uint32_t npages, uint32_t flags)
if ((j >= npages) && (viraddr < end))
ret = viraddr;
spinlock_unlock(pgd_lock);
if (flags & MAP_KERNEL_SPACE)
spinlock_unlock(&kslock);
else
spinlock_irqsave_unlock(&task->pgd_lock);
return ret;
}
@ -522,7 +517,6 @@ size_t vm_alloc(uint32_t npages, uint32_t flags)
int unmap_region(size_t viraddr, uint32_t npages)
{
task_t* task = per_core(current_task);
spinlock_t* pgd_lock;
uint32_t i;
uint32_t index1, index2;
page_table_t* pgt;
@ -531,11 +525,9 @@ int unmap_region(size_t viraddr, uint32_t npages)
return -EINVAL;
if (viraddr <= KERNEL_SPACE)
pgd_lock = &kslock;
spinlock_lock(&kslock);
else
pgd_lock = &task->pgd_lock;
spinlock_lock(pgd_lock);
spinlock_irqsave_lock(&task->pgd_lock);
for(i=0; i<npages; i++, viraddr+=PAGE_SIZE)
{
@ -553,7 +545,10 @@ int unmap_region(size_t viraddr, uint32_t npages)
tlb_flush_one_page(viraddr);
}
spinlock_unlock(pgd_lock);
if (viraddr <= KERNEL_SPACE)
spinlock_unlock(&kslock);
else
spinlock_irqsave_unlock(&task->pgd_lock);
return 0;
}
@ -561,7 +556,6 @@ int unmap_region(size_t viraddr, uint32_t npages)
int vm_free(size_t viraddr, uint32_t npages)
{
task_t* task = per_core(current_task);
spinlock_t* pgd_lock;
uint32_t i;
uint32_t index1, index2;
page_table_t* pgt;
@ -570,11 +564,9 @@ int vm_free(size_t viraddr, uint32_t npages)
return -EINVAL;
if (viraddr <= KERNEL_SPACE)
pgd_lock = &kslock;
spinlock_lock(&kslock);
else
pgd_lock = &task->pgd_lock;
spinlock_lock(pgd_lock);
spinlock_irqsave_lock(&task->pgd_lock);
for(i=0; i<npages; i++, viraddr+=PAGE_SIZE)
{
@ -589,7 +581,10 @@ int vm_free(size_t viraddr, uint32_t npages)
tlb_flush_one_page(viraddr);
}
spinlock_unlock(pgd_lock);
if (viraddr <= KERNEL_SPACE)
spinlock_unlock(&kslock);
else
spinlock_irqsave_unlock(&task->pgd_lock);
return 0;
}
@ -607,7 +602,7 @@ int print_paging_tree(size_t viraddr)
index1 = viraddr >> 22;
index2 = (viraddr >> 12) & 0x3FF;
spinlock_lock(&task->pgd_lock);
spinlock_irqsave_lock(&task->pgd_lock);
kprintf("Paging dump of address 0x%x\n", viraddr);
pgd = task->pgd;
@ -628,7 +623,7 @@ int print_paging_tree(size_t viraddr)
else
kputs("invalid page table\n");
spinlock_unlock(&task->pgd_lock);
spinlock_irqsave_unlock(&task->pgd_lock);
return 0;
}

2
include/metalsvm/tasks_types.h
View file

@ -89,7 +89,7 @@ typedef struct task {
/// usage in number of pages
atomic_int32_t user_usage;
/// avoids concurrent access to the page directory
spinlock_t pgd_lock;
spinlock_irqsave_t pgd_lock;
/// pointer to the page directory
struct page_dir* pgd;
/// lock for the VMA_list

4
kernel/tasks.c
View file

@ -47,8 +47,8 @@
* A task's id will be its position in this array.
*/
static task_t task_table[MAX_TASKS] = { \
[0] = {0, TASK_IDLE, NULL, NULL, 0, 0, 0, NULL, NULL, 0, ATOMIC_INIT(0), SPINLOCK_INIT, NULL, SPINLOCK_INIT, NULL, NULL, 0, 0, 0, 0}, \
[1 ... MAX_TASKS-1] = {0, TASK_INVALID, NULL, NULL, 0, 0, 0, NULL, NULL, 0, ATOMIC_INIT(0), SPINLOCK_INIT, NULL, SPINLOCK_INIT, NULL, NULL, 0, 0, 0, 0}};
[0] = {0, TASK_IDLE, NULL, NULL, 0, 0, 0, NULL, NULL, 0, ATOMIC_INIT(0), SPINLOCK_IRQSAVE_INIT, NULL, SPINLOCK_INIT, NULL, NULL, 0, 0, 0, 0}, \
[1 ... MAX_TASKS-1] = {0, TASK_INVALID, NULL, NULL, 0, 0, 0, NULL, NULL, 0, ATOMIC_INIT(0), SPINLOCK_IRQSAVE_INIT, NULL, SPINLOCK_INIT, NULL, NULL, 0, 0, 0, 0}};
static spinlock_irqsave_t table_lock = SPINLOCK_IRQSAVE_INIT;
#ifndef CONFIG_TICKLESS
#if MAX_CORES > 1