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-rw-r--r--lib/Kconfig.debug15
-rw-r--r--lib/is_single_threaded.c61
-rw-r--r--lib/swiotlb.c124
3 files changed, 96 insertions, 104 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 82fbc49728d..7dbd5d9c29a 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -653,6 +653,21 @@ config DEBUG_NOTIFIERS
This is a relatively cheap check but if you care about maximum
performance, say N.
+config DEBUG_CREDENTIALS
+ bool "Debug credential management"
+ depends on DEBUG_KERNEL
+ help
+ Enable this to turn on some debug checking for credential
+ management. The additional code keeps track of the number of
+ pointers from task_structs to any given cred struct, and checks to
+ see that this number never exceeds the usage count of the cred
+ struct.
+
+ Furthermore, if SELinux is enabled, this also checks that the
+ security pointer in the cred struct is never seen to be invalid.
+
+ If unsure, say N.
+
#
# Select this config option from the architecture Kconfig, if it
# it is preferred to always offer frame pointers as a config
diff --git a/lib/is_single_threaded.c b/lib/is_single_threaded.c
index f1ed2fe76c6..bd2bea96336 100644
--- a/lib/is_single_threaded.c
+++ b/lib/is_single_threaded.c
@@ -12,34 +12,47 @@
#include <linux/sched.h>
-/**
- * is_single_threaded - Determine if a thread group is single-threaded or not
- * @p: A task in the thread group in question
- *
- * This returns true if the thread group to which a task belongs is single
- * threaded, false if it is not.
+/*
+ * Returns true if the task does not share ->mm with another thread/process.
*/
-bool is_single_threaded(struct task_struct *p)
+bool current_is_single_threaded(void)
{
- struct task_struct *g, *t;
- struct mm_struct *mm = p->mm;
+ struct task_struct *task = current;
+ struct mm_struct *mm = task->mm;
+ struct task_struct *p, *t;
+ bool ret;
- if (atomic_read(&p->signal->count) != 1)
- goto no;
+ if (atomic_read(&task->signal->live) != 1)
+ return false;
- if (atomic_read(&p->mm->mm_users) != 1) {
- read_lock(&tasklist_lock);
- do_each_thread(g, t) {
- if (t->mm == mm && t != p)
- goto no_unlock;
- } while_each_thread(g, t);
- read_unlock(&tasklist_lock);
- }
+ if (atomic_read(&mm->mm_users) == 1)
+ return true;
- return true;
+ ret = false;
+ rcu_read_lock();
+ for_each_process(p) {
+ if (unlikely(p->flags & PF_KTHREAD))
+ continue;
+ if (unlikely(p == task->group_leader))
+ continue;
+
+ t = p;
+ do {
+ if (unlikely(t->mm == mm))
+ goto found;
+ if (likely(t->mm))
+ break;
+ /*
+ * t->mm == NULL. Make sure next_thread/next_task
+ * will see other CLONE_VM tasks which might be
+ * forked before exiting.
+ */
+ smp_rmb();
+ } while_each_thread(p, t);
+ }
+ ret = true;
+found:
+ rcu_read_unlock();
-no_unlock:
- read_unlock(&tasklist_lock);
-no:
- return false;
+ return ret;
}
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index bffe6d7ef9d..ac25cd28e80 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -114,46 +114,11 @@ setup_io_tlb_npages(char *str)
__setup("swiotlb=", setup_io_tlb_npages);
/* make io_tlb_overflow tunable too? */
-void * __weak __init swiotlb_alloc_boot(size_t size, unsigned long nslabs)
-{
- return alloc_bootmem_low_pages(size);
-}
-
-void * __weak swiotlb_alloc(unsigned order, unsigned long nslabs)
-{
- return (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN, order);
-}
-
-dma_addr_t __weak swiotlb_phys_to_bus(struct device *hwdev, phys_addr_t paddr)
-{
- return paddr;
-}
-
-phys_addr_t __weak swiotlb_bus_to_phys(struct device *hwdev, dma_addr_t baddr)
-{
- return baddr;
-}
-
+/* Note that this doesn't work with highmem page */
static dma_addr_t swiotlb_virt_to_bus(struct device *hwdev,
volatile void *address)
{
- return swiotlb_phys_to_bus(hwdev, virt_to_phys(address));
-}
-
-void * __weak swiotlb_bus_to_virt(struct device *hwdev, dma_addr_t address)
-{
- return phys_to_virt(swiotlb_bus_to_phys(hwdev, address));
-}
-
-int __weak swiotlb_arch_address_needs_mapping(struct device *hwdev,
- dma_addr_t addr, size_t size)
-{
- return !is_buffer_dma_capable(dma_get_mask(hwdev), addr, size);
-}
-
-int __weak swiotlb_arch_range_needs_mapping(phys_addr_t paddr, size_t size)
-{
- return 0;
+ return phys_to_dma(hwdev, virt_to_phys(address));
}
static void swiotlb_print_info(unsigned long bytes)
@@ -189,7 +154,7 @@ swiotlb_init_with_default_size(size_t default_size)
/*
* Get IO TLB memory from the low pages
*/
- io_tlb_start = swiotlb_alloc_boot(bytes, io_tlb_nslabs);
+ io_tlb_start = alloc_bootmem_low_pages(bytes);
if (!io_tlb_start)
panic("Cannot allocate SWIOTLB buffer");
io_tlb_end = io_tlb_start + bytes;
@@ -245,7 +210,8 @@ swiotlb_late_init_with_default_size(size_t default_size)
bytes = io_tlb_nslabs << IO_TLB_SHIFT;
while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) {
- io_tlb_start = swiotlb_alloc(order, io_tlb_nslabs);
+ io_tlb_start = (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN,
+ order);
if (io_tlb_start)
break;
order--;
@@ -315,20 +281,10 @@ cleanup1:
return -ENOMEM;
}
-static inline int
-address_needs_mapping(struct device *hwdev, dma_addr_t addr, size_t size)
+static int is_swiotlb_buffer(phys_addr_t paddr)
{
- return swiotlb_arch_address_needs_mapping(hwdev, addr, size);
-}
-
-static inline int range_needs_mapping(phys_addr_t paddr, size_t size)
-{
- return swiotlb_force || swiotlb_arch_range_needs_mapping(paddr, size);
-}
-
-static int is_swiotlb_buffer(char *addr)
-{
- return addr >= io_tlb_start && addr < io_tlb_end;
+ return paddr >= virt_to_phys(io_tlb_start) &&
+ paddr < virt_to_phys(io_tlb_end);
}
/*
@@ -561,9 +517,7 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
dma_mask = hwdev->coherent_dma_mask;
ret = (void *)__get_free_pages(flags, order);
- if (ret &&
- !is_buffer_dma_capable(dma_mask, swiotlb_virt_to_bus(hwdev, ret),
- size)) {
+ if (ret && swiotlb_virt_to_bus(hwdev, ret) + size > dma_mask) {
/*
* The allocated memory isn't reachable by the device.
*/
@@ -585,7 +539,7 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
dev_addr = swiotlb_virt_to_bus(hwdev, ret);
/* Confirm address can be DMA'd by device */
- if (!is_buffer_dma_capable(dma_mask, dev_addr, size)) {
+ if (dev_addr + size > dma_mask) {
printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n",
(unsigned long long)dma_mask,
(unsigned long long)dev_addr);
@@ -601,11 +555,13 @@ EXPORT_SYMBOL(swiotlb_alloc_coherent);
void
swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
- dma_addr_t dma_handle)
+ dma_addr_t dev_addr)
{
+ phys_addr_t paddr = dma_to_phys(hwdev, dev_addr);
+
WARN_ON(irqs_disabled());
- if (!is_swiotlb_buffer(vaddr))
- free_pages((unsigned long) vaddr, get_order(size));
+ if (!is_swiotlb_buffer(paddr))
+ free_pages((unsigned long)vaddr, get_order(size));
else
/* DMA_TO_DEVICE to avoid memcpy in unmap_single */
do_unmap_single(hwdev, vaddr, size, DMA_TO_DEVICE);
@@ -625,12 +581,15 @@ swiotlb_full(struct device *dev, size_t size, int dir, int do_panic)
printk(KERN_ERR "DMA: Out of SW-IOMMU space for %zu bytes at "
"device %s\n", size, dev ? dev_name(dev) : "?");
- if (size > io_tlb_overflow && do_panic) {
- if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)
- panic("DMA: Memory would be corrupted\n");
- if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)
- panic("DMA: Random memory would be DMAed\n");
- }
+ if (size <= io_tlb_overflow || !do_panic)
+ return;
+
+ if (dir == DMA_BIDIRECTIONAL)
+ panic("DMA: Random memory could be DMA accessed\n");
+ if (dir == DMA_FROM_DEVICE)
+ panic("DMA: Random memory could be DMA written\n");
+ if (dir == DMA_TO_DEVICE)
+ panic("DMA: Random memory could be DMA read\n");
}
/*
@@ -646,7 +605,7 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
struct dma_attrs *attrs)
{
phys_addr_t phys = page_to_phys(page) + offset;
- dma_addr_t dev_addr = swiotlb_phys_to_bus(dev, phys);
+ dma_addr_t dev_addr = phys_to_dma(dev, phys);
void *map;
BUG_ON(dir == DMA_NONE);
@@ -655,8 +614,7 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
* we can safely return the device addr and not worry about bounce
* buffering it.
*/
- if (!address_needs_mapping(dev, dev_addr, size) &&
- !range_needs_mapping(phys, size))
+ if (dma_capable(dev, dev_addr, size) && !swiotlb_force)
return dev_addr;
/*
@@ -673,7 +631,7 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
/*
* Ensure that the address returned is DMA'ble
*/
- if (address_needs_mapping(dev, dev_addr, size))
+ if (!dma_capable(dev, dev_addr, size))
panic("map_single: bounce buffer is not DMA'ble");
return dev_addr;
@@ -691,19 +649,25 @@ EXPORT_SYMBOL_GPL(swiotlb_map_page);
static void unmap_single(struct device *hwdev, dma_addr_t dev_addr,
size_t size, int dir)
{
- char *dma_addr = swiotlb_bus_to_virt(hwdev, dev_addr);
+ phys_addr_t paddr = dma_to_phys(hwdev, dev_addr);
BUG_ON(dir == DMA_NONE);
- if (is_swiotlb_buffer(dma_addr)) {
- do_unmap_single(hwdev, dma_addr, size, dir);
+ if (is_swiotlb_buffer(paddr)) {
+ do_unmap_single(hwdev, phys_to_virt(paddr), size, dir);
return;
}
if (dir != DMA_FROM_DEVICE)
return;
- dma_mark_clean(dma_addr, size);
+ /*
+ * phys_to_virt doesn't work with hihgmem page but we could
+ * call dma_mark_clean() with hihgmem page here. However, we
+ * are fine since dma_mark_clean() is null on POWERPC. We can
+ * make dma_mark_clean() take a physical address if necessary.
+ */
+ dma_mark_clean(phys_to_virt(paddr), size);
}
void swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr,
@@ -728,19 +692,19 @@ static void
swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr,
size_t size, int dir, int target)
{
- char *dma_addr = swiotlb_bus_to_virt(hwdev, dev_addr);
+ phys_addr_t paddr = dma_to_phys(hwdev, dev_addr);
BUG_ON(dir == DMA_NONE);
- if (is_swiotlb_buffer(dma_addr)) {
- sync_single(hwdev, dma_addr, size, dir, target);
+ if (is_swiotlb_buffer(paddr)) {
+ sync_single(hwdev, phys_to_virt(paddr), size, dir, target);
return;
}
if (dir != DMA_FROM_DEVICE)
return;
- dma_mark_clean(dma_addr, size);
+ dma_mark_clean(phys_to_virt(paddr), size);
}
void
@@ -817,10 +781,10 @@ swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems,
for_each_sg(sgl, sg, nelems, i) {
phys_addr_t paddr = sg_phys(sg);
- dma_addr_t dev_addr = swiotlb_phys_to_bus(hwdev, paddr);
+ dma_addr_t dev_addr = phys_to_dma(hwdev, paddr);
- if (range_needs_mapping(paddr, sg->length) ||
- address_needs_mapping(hwdev, dev_addr, sg->length)) {
+ if (swiotlb_force ||
+ !dma_capable(hwdev, dev_addr, sg->length)) {
void *map = map_single(hwdev, sg_phys(sg),
sg->length, dir);
if (!map) {
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-27 10:21:06 +0000