diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig.debug | 15 | ||||
| -rw-r--r-- | lib/is_single_threaded.c | 61 | ||||
| -rw-r--r-- | lib/swiotlb.c | 124 |
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) { |