diff options
Diffstat (limited to 'mm/vmalloc.c')
| -rw-r--r-- | mm/vmalloc.c | 572 |
1 files changed, 338 insertions, 234 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 871e41c55e23..e5e9e1fcac01 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -18,6 +18,7 @@ #include <linux/interrupt.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> +#include <linux/set_memory.h> #include <linux/debugobjects.h> #include <linux/kallsyms.h> #include <linux/list.h> @@ -498,7 +499,11 @@ nocache: } found: - if (addr + size > vend) + /* + * Check also calculated address against the vstart, + * because it can be 0 because of big align request. + */ + if (addr + size > vend || addr < vstart) goto overflow; va->va_start = addr; @@ -840,7 +845,7 @@ static void *vmap_block_vaddr(unsigned long va_start, unsigned long pages_off) * @order: how many 2^order pages should be occupied in newly allocated block * @gfp_mask: flags for the page level allocator * - * Returns: virtual address in a newly allocated block or ERR_PTR(-errno) + * Return: virtual address in a newly allocated block or ERR_PTR(-errno) */ static void *new_vmap_block(unsigned int order, gfp_t gfp_mask) { @@ -1055,24 +1060,9 @@ static void vb_free(const void *addr, unsigned long size) spin_unlock(&vb->lock); } -/** - * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer - * - * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily - * to amortize TLB flushing overheads. What this means is that any page you - * have now, may, in a former life, have been mapped into kernel virtual - * address by the vmap layer and so there might be some CPUs with TLB entries - * still referencing that page (additional to the regular 1:1 kernel mapping). - * - * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can - * be sure that none of the pages we have control over will have any aliases - * from the vmap layer. - */ -void vm_unmap_aliases(void) +static void _vm_unmap_aliases(unsigned long start, unsigned long end, int flush) { - unsigned long start = ULONG_MAX, end = 0; int cpu; - int flush = 0; if (unlikely(!vmap_initialized)) return; @@ -1109,6 +1099,27 @@ void vm_unmap_aliases(void) flush_tlb_kernel_range(start, end); mutex_unlock(&vmap_purge_lock); } + +/** + * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer + * + * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily + * to amortize TLB flushing overheads. What this means is that any page you + * have now, may, in a former life, have been mapped into kernel virtual + * address by the vmap layer and so there might be some CPUs with TLB entries + * still referencing that page (additional to the regular 1:1 kernel mapping). + * + * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can + * be sure that none of the pages we have control over will have any aliases + * from the vmap layer. + */ +void vm_unmap_aliases(void) +{ + unsigned long start = ULONG_MAX, end = 0; + int flush = 0; + + _vm_unmap_aliases(start, end, flush); +} EXPORT_SYMBOL_GPL(vm_unmap_aliases); /** @@ -1187,6 +1198,7 @@ void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t pro EXPORT_SYMBOL(vm_map_ram); static struct vm_struct *vmlist __initdata; + /** * vm_area_add_early - add vmap area early during boot * @vm: vm_struct to add @@ -1421,13 +1433,15 @@ struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags, } /** - * get_vm_area - reserve a contiguous kernel virtual area - * @size: size of the area - * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC + * get_vm_area - reserve a contiguous kernel virtual area + * @size: size of the area + * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC + * + * Search an area of @size in the kernel virtual mapping area, + * and reserved it for out purposes. Returns the area descriptor + * on success or %NULL on failure. * - * Search an area of @size in the kernel virtual mapping area, - * and reserved it for out purposes. Returns the area descriptor - * on success or %NULL on failure. + * Return: the area descriptor on success or %NULL on failure. */ struct vm_struct *get_vm_area(unsigned long size, unsigned long flags) { @@ -1444,12 +1458,14 @@ struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags, } /** - * find_vm_area - find a continuous kernel virtual area - * @addr: base address + * find_vm_area - find a continuous kernel virtual area + * @addr: base address * - * Search for the kernel VM area starting at @addr, and return it. - * It is up to the caller to do all required locking to keep the returned - * pointer valid. + * Search for the kernel VM area starting at @addr, and return it. + * It is up to the caller to do all required locking to keep the returned + * pointer valid. + * + * Return: pointer to the found area or %NULL on faulure */ struct vm_struct *find_vm_area(const void *addr) { @@ -1463,12 +1479,14 @@ struct vm_struct *find_vm_area(const void *addr) } /** - * remove_vm_area - find and remove a continuous kernel virtual area - * @addr: base address + * remove_vm_area - find and remove a continuous kernel virtual area + * @addr: base address + * + * Search for the kernel VM area starting at @addr, and remove it. + * This function returns the found VM area, but using it is NOT safe + * on SMP machines, except for its size or flags. * - * Search for the kernel VM area starting at @addr, and remove it. - * This function returns the found VM area, but using it is NOT safe - * on SMP machines, except for its size or flags. + * Return: pointer to the found area or %NULL on faulure */ struct vm_struct *remove_vm_area(const void *addr) { @@ -1494,6 +1512,72 @@ struct vm_struct *remove_vm_area(const void *addr) return NULL; } +static inline void set_area_direct_map(const struct vm_struct *area, + int (*set_direct_map)(struct page *page)) +{ + int i; + + for (i = 0; i < area->nr_pages; i++) + if (page_address(area->pages[i])) + set_direct_map(area->pages[i]); +} + +/* Handle removing and resetting vm mappings related to the vm_struct. */ +static void vm_remove_mappings(struct vm_struct *area, int deallocate_pages) +{ + unsigned long addr = (unsigned long)area->addr; + unsigned long start = ULONG_MAX, end = 0; + int flush_reset = area->flags & VM_FLUSH_RESET_PERMS; + int i; + + /* + * The below block can be removed when all architectures that have + * direct map permissions also have set_direct_map_() implementations. + * This is concerned with resetting the direct map any an vm alias with + * execute permissions, without leaving a RW+X window. + */ + if (flush_reset && !IS_ENABLED(CONFIG_ARCH_HAS_SET_DIRECT_MAP)) { + set_memory_nx(addr, area->nr_pages); + set_memory_rw(addr, area->nr_pages); + } + + remove_vm_area(area->addr); + + /* If this is not VM_FLUSH_RESET_PERMS memory, no need for the below. */ + if (!flush_reset) + return; + + /* + * If not deallocating pages, just do the flush of the VM area and + * return. + */ + if (!deallocate_pages) { + vm_unmap_aliases(); + return; + } + + /* + * If execution gets here, flush the vm mapping and reset the direct + * map. Find the start and end range of the direct mappings to make sure + * the vm_unmap_aliases() flush includes the direct map. + */ + for (i = 0; i < area->nr_pages; i++) { + if (page_address(area->pages[i])) { + start = min(addr, start); + end = max(addr, end); + } + } + + /* + * Set direct map to something invalid so that it won't be cached if + * there are any accesses after the TLB flush, then flush the TLB and + * reset the direct map permissions to the default. + */ + set_area_direct_map(area, set_direct_map_invalid_noflush); + _vm_unmap_aliases(start, end, 1); + set_area_direct_map(area, set_direct_map_default_noflush); +} + static void __vunmap(const void *addr, int deallocate_pages) { struct vm_struct *area; @@ -1505,7 +1589,7 @@ static void __vunmap(const void *addr, int deallocate_pages) addr)) return; - area = find_vmap_area((unsigned long)addr)->vm; + area = find_vm_area(addr); if (unlikely(!area)) { WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n", addr); @@ -1515,7 +1599,8 @@ static void __vunmap(const void *addr, int deallocate_pages) debug_check_no_locks_freed(area->addr, get_vm_area_size(area)); debug_check_no_obj_freed(area->addr, get_vm_area_size(area)); - remove_vm_area(addr); + vm_remove_mappings(area, deallocate_pages); + if (deallocate_pages) { int i; @@ -1548,11 +1633,11 @@ static inline void __vfree_deferred(const void *addr) } /** - * vfree_atomic - release memory allocated by vmalloc() - * @addr: memory base address + * vfree_atomic - release memory allocated by vmalloc() + * @addr: memory base address * - * This one is just like vfree() but can be called in any atomic context - * except NMIs. + * This one is just like vfree() but can be called in any atomic context + * except NMIs. */ void vfree_atomic(const void *addr) { @@ -1565,21 +1650,29 @@ void vfree_atomic(const void *addr) __vfree_deferred(addr); } +static void __vfree(const void *addr) +{ + if (unlikely(in_interrupt())) + __vfree_deferred(addr); + else + __vunmap(addr, 1); +} + /** - * vfree - release memory allocated by vmalloc() - * @addr: memory base address + * vfree - release memory allocated by vmalloc() + * @addr: memory base address * - * Free the virtually continuous memory area starting at @addr, as - * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is - * NULL, no operation is performed. + * Free the virtually continuous memory area starting at @addr, as + * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is + * NULL, no operation is performed. * - * Must not be called in NMI context (strictly speaking, only if we don't - * have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling - * conventions for vfree() arch-depenedent would be a really bad idea) + * Must not be called in NMI context (strictly speaking, only if we don't + * have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling + * conventions for vfree() arch-depenedent would be a really bad idea) * - * May sleep if called *not* from interrupt context. + * May sleep if called *not* from interrupt context. * - * NOTE: assumes that the object at @addr has a size >= sizeof(llist_node) + * NOTE: assumes that the object at @addr has a size >= sizeof(llist_node) */ void vfree(const void *addr) { @@ -1591,21 +1684,19 @@ void vfree(const void *addr) if (!addr) return; - if (unlikely(in_interrupt())) - __vfree_deferred(addr); - else - __vunmap(addr, 1); + + __vfree(addr); } EXPORT_SYMBOL(vfree); /** - * vunmap - release virtual mapping obtained by vmap() - * @addr: memory base address + * vunmap - release virtual mapping obtained by vmap() + * @addr: memory base address * - * Free the virtually contiguous memory area starting at @addr, - * which was created from the page array passed to vmap(). + * Free the virtually contiguous memory area starting at @addr, + * which was created from the page array passed to vmap(). * - * Must not be called in interrupt context. + * Must not be called in interrupt context. */ void vunmap(const void *addr) { @@ -1617,17 +1708,19 @@ void vunmap(const void *addr) EXPORT_SYMBOL(vunmap); /** - * vmap - map an array of pages into virtually contiguous space - * @pages: array of page pointers - * @count: number of pages to map - * @flags: vm_area->flags - * @prot: page protection for the mapping - * - * Maps @count pages from @pages into contiguous kernel virtual - * space. + * vmap - map an array of pages into virtually contiguous space + * @pages: array of page pointers + * @count: number of pages to map + * @flags: vm_area->flags + * @prot: page protection for the mapping + * + * Maps @count pages from @pages into contiguous kernel virtual + * space. + * + * Return: the address of the area or %NULL on failure */ void *vmap(struct page **pages, unsigned int count, - unsigned long flags, pgprot_t prot) + unsigned long flags, pgprot_t prot) { struct vm_struct *area; unsigned long size; /* In bytes */ @@ -1709,25 +1802,27 @@ fail: warn_alloc(gfp_mask, NULL, "vmalloc: allocation failure, allocated %ld of %ld bytes", (area->nr_pages*PAGE_SIZE), area->size); - vfree(area->addr); + __vfree(area->addr); return NULL; } /** - * __vmalloc_node_range - allocate virtually contiguous memory - * @size: allocation size - * @align: desired alignment - * @start: vm area range start - * @end: vm area range end - * @gfp_mask: flags for the page level allocator - * @prot: protection mask for the allocated pages - * @vm_flags: additional vm area flags (e.g. %VM_NO_GUARD) - * @node: node to use for allocation or NUMA_NO_NODE - * @caller: caller's return address - * - * Allocate enough pages to cover @size from the page level - * allocator with @gfp_mask flags. Map them into contiguous - * kernel virtual space, using a pagetable protection of @prot. + * __vmalloc_node_range - allocate virtually contiguous memory + * @size: allocation size + * @align: desired alignment + * @start: vm area range start + * @end: vm area range end + * @gfp_mask: flags for the page level allocator + * @prot: protection mask for the allocated pages + * @vm_flags: additional vm area flags (e.g. %VM_NO_GUARD) + * @node: node to use for allocation or NUMA_NO_NODE + * @caller: caller's return address + * + * Allocate enough pages to cover @size from the page level + * allocator with @gfp_mask flags. Map them into contiguous + * kernel virtual space, using a pagetable protection of @prot. + * + * Return: the address of the area or %NULL on failure */ void *__vmalloc_node_range(unsigned long size, unsigned long align, unsigned long start, unsigned long end, gfp_t gfp_mask, @@ -1768,25 +1863,35 @@ fail: return NULL; } +/* + * This is only for performance analysis of vmalloc and stress purpose. + * It is required by vmalloc test module, therefore do not use it other + * than that. + */ +#ifdef CONFIG_TEST_VMALLOC_MODULE +EXPORT_SYMBOL_GPL(__vmalloc_node_range); +#endif + /** - * __vmalloc_node - allocate virtually contiguous memory - * @size: allocation size - * @align: desired alignment - * @gfp_mask: flags for the page level allocator - * @prot: protection mask for the allocated pages - * @node: node to use for allocation or NUMA_NO_NODE - * @caller: caller's return address + * __vmalloc_node - allocate virtually contiguous memory + * @size: allocation size + * @align: desired alignment + * @gfp_mask: flags for the page level allocator + * @prot: protection mask for the allocated pages + * @node: node to use for allocation or NUMA_NO_NODE + * @caller: caller's return address * - * Allocate enough pages to cover @size from the page level - * allocator with @gfp_mask flags. Map them into contiguous - * kernel virtual space, using a pagetable protection of @prot. + * Allocate enough pages to cover @size from the page level + * allocator with @gfp_mask flags. Map them into contiguous + * kernel virtual space, using a pagetable protection of @prot. * - * Reclaim modifiers in @gfp_mask - __GFP_NORETRY, __GFP_RETRY_MAYFAIL - * and __GFP_NOFAIL are not supported + * Reclaim modifiers in @gfp_mask - __GFP_NORETRY, __GFP_RETRY_MAYFAIL + * and __GFP_NOFAIL are not supported * - * Any use of gfp flags outside of GFP_KERNEL should be consulted - * with mm people. + * Any use of gfp flags outside of GFP_KERNEL should be consulted + * with mm people. * + * Return: pointer to the allocated memory or %NULL on error */ static void *__vmalloc_node(unsigned long size, unsigned long align, gfp_t gfp_mask, pgprot_t prot, @@ -1818,13 +1923,16 @@ void *__vmalloc_node_flags_caller(unsigned long size, int node, gfp_t flags, } /** - * vmalloc - allocate virtually contiguous memory - * @size: allocation size - * Allocate enough pages to cover @size from the page level - * allocator and map them into contiguous kernel virtual space. + * vmalloc - allocate virtually contiguous memory + * @size: allocation size + * + * Allocate enough pages to cover @size from the page level + * allocator and map them into contiguous kernel virtual space. + * + * For tight control over page level allocator and protection flags + * use __vmalloc() instead. * - * For tight control over page level allocator and protection flags - * use __vmalloc() instead. + * Return: pointer to the allocated memory or %NULL on error */ void *vmalloc(unsigned long size) { @@ -1834,14 +1942,17 @@ void *vmalloc(unsigned long size) EXPORT_SYMBOL(vmalloc); /** - * vzalloc - allocate virtually contiguous memory with zero fill - * @size: allocation size - * Allocate enough pages to cover @size from the page level - * allocator and map them into contiguous kernel virtual space. - * The memory allocated is set to zero. - * - * For tight control over page level allocator and protection flags - * use __vmalloc() instead. + * vzalloc - allocate virtually contiguous memory with zero fill + * @size: allocation size + * + * Allocate enough pages to cover @size from the page level + * allocator and map them into contiguous kernel virtual space. + * The memory allocated is set to zero. + * + * For tight control over page level allocator and protection flags + * use __vmalloc() instead. + * + * Return: pointer to the allocated memory or %NULL on error */ void *vzalloc(unsigned long size) { @@ -1856,34 +1967,30 @@ EXPORT_SYMBOL(vzalloc); * * The resulting memory area is zeroed so it can be mapped to userspace * without leaking data. + * + * Return: pointer to the allocated memory or %NULL on error */ void *vmalloc_user(unsigned long size) { - struct vm_struct *area; - void *ret; - - ret = __vmalloc_node(size, SHMLBA, - GFP_KERNEL | __GFP_ZERO, - PAGE_KERNEL, NUMA_NO_NODE, - __builtin_return_address(0)); - if (ret) { - area = find_vm_area(ret); - area->flags |= VM_USERMAP; - } - return ret; + return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END, + GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL, + VM_USERMAP, NUMA_NO_NODE, + __builtin_return_address(0)); } EXPORT_SYMBOL(vmalloc_user); /** - * vmalloc_node - allocate memory on a specific node - * @size: allocation size - * @node: numa node + * vmalloc_node - allocate memory on a specific node + * @size: allocation size + * @node: numa node + * + * Allocate enough pages to cover @size from the page level + * allocator and map them into contiguous kernel virtual space. * - * Allocate enough pages to cover @size from the page level - * allocator and map them into contiguous kernel virtual space. + * For tight control over page level allocator and protection flags + * use __vmalloc() instead. * - * For tight control over page level allocator and protection flags - * use __vmalloc() instead. + * Return: pointer to the allocated memory or %NULL on error */ void *vmalloc_node(unsigned long size, int node) { @@ -1903,6 +2010,8 @@ EXPORT_SYMBOL(vmalloc_node); * * For tight control over page level allocator and protection flags * use __vmalloc_node() instead. + * + * Return: pointer to the allocated memory or %NULL on error */ void *vzalloc_node(unsigned long size, int node) { @@ -1912,21 +2021,23 @@ void *vzalloc_node(unsigned long size, int node) EXPORT_SYMBOL(vzalloc_node); /** - * vmalloc_exec - allocate virtually contiguous, executable memory - * @size: allocation size + * vmalloc_exec - allocate virtually contiguous, executable memory + * @size: allocation size * - * Kernel-internal function to allocate enough pages to cover @size - * the page level allocator and map them into contiguous and - * executable kernel virtual space. + * Kernel-internal function to allocate enough pages to cover @size + * the page level allocator and map them into contiguous and + * executable kernel virtual space. + * + * For tight control over page level allocator and protection flags + * use __vmalloc() instead. * - * For tight control over page level allocator and protection flags - * use __vmalloc() instead. + * Return: pointer to the allocated memory or %NULL on error */ - void *vmalloc_exec(unsigned long size) { - return __vmalloc_node(size, 1, GFP_KERNEL, PAGE_KERNEL_EXEC, - NUMA_NO_NODE, __builtin_return_address(0)); + return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END, + GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS, + NUMA_NO_NODE, __builtin_return_address(0)); } #if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32) @@ -1942,11 +2053,13 @@ void *vmalloc_exec(unsigned long size) #endif /** - * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) - * @size: allocation size + * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) + * @size: allocation size * - * Allocate enough 32bit PA addressable pages to cover @size from the - * page level allocator and map them into contiguous kernel virtual space. + * Allocate enough 32bit PA addressable pages to cover @size from the + * page level allocator and map them into contiguous kernel virtual space. + * + * Return: pointer to the allocated memory or %NULL on error */ void *vmalloc_32(unsigned long size) { @@ -1957,23 +2070,19 @@ EXPORT_SYMBOL(vmalloc_32); /** * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory - * @size: allocation size + * @size: allocation size * * The resulting memory area is 32bit addressable and zeroed so it can be * mapped to userspace without leaking data. + * + * Return: pointer to the allocated memory or %NULL on error */ void *vmalloc_32_user(unsigned long size) { - struct vm_struct *area; - void *ret; - - ret = __vmalloc_node(size, 1, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL, - NUMA_NO_NODE, __builtin_return_address(0)); - if (ret) { - area = find_vm_area(ret); - area->flags |= VM_USERMAP; - } - return ret; + return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END, + GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL, + VM_USERMAP, NUMA_NO_NODE, + __builtin_return_address(0)); } EXPORT_SYMBOL(vmalloc_32_user); @@ -2059,31 +2168,29 @@ static int aligned_vwrite(char *buf, char *addr, unsigned long count) } /** - * vread() - read vmalloc area in a safe way. - * @buf: buffer for reading data - * @addr: vm address. - * @count: number of bytes to be read. - * - * Returns # of bytes which addr and buf should be increased. - * (same number to @count). Returns 0 if [addr...addr+count) doesn't - * includes any intersect with alive vmalloc area. - * - * This function checks that addr is a valid vmalloc'ed area, and - * copy data from that area to a given buffer. If the given memory range - * of [addr...addr+count) includes some valid address, data is copied to - * proper area of @buf. If there are memory holes, they'll be zero-filled. - * IOREMAP area is treated as memory hole and no copy is done. - * - * If [addr...addr+count) doesn't includes any intersects with alive - * vm_struct area, returns 0. @buf should be kernel's buffer. - * - * Note: In usual ops, vread() is never necessary because the caller - * should know vmalloc() area is valid and can use memcpy(). - * This is for routines which have to access vmalloc area without - * any informaion, as /dev/kmem. - * + * vread() - read vmalloc area in a safe way. + * @buf: buffer for reading data + * @addr: vm address. + * @count: number of bytes to be read. + * + * This function checks that addr is a valid vmalloc'ed area, and + * copy data from that area to a given buffer. If the given memory range + * of [addr...addr+count) includes some valid address, data is copied to + * proper area of @buf. If there are memory holes, they'll be zero-filled. + * IOREMAP area is treated as memory hole and no copy is done. + * + * If [addr...addr+count) doesn't includes any intersects with alive + * vm_struct area, returns 0. @buf should be kernel's buffer. + * + * Note: In usual ops, vread() is never necessary because the caller + * should know vmalloc() area is valid and can use memcpy(). + * This is for routines which have to access vmalloc area without + * any informaion, as /dev/kmem. + * + * Return: number of bytes for which addr and buf should be increased + * (same number as @count) or %0 if [addr...addr+count) doesn't + * include any intersection with valid vmalloc area */ - long vread(char *buf, char *addr, unsigned long count) { struct vmap_area *va; @@ -2140,31 +2247,29 @@ finished: } /** - * vwrite() - write vmalloc area in a safe way. - * @buf: buffer for source data - * @addr: vm address. - * @count: number of bytes to be read. - * - * Returns # of bytes which addr and buf should be incresed. - * (same number to @count). - * If [addr...addr+count) doesn't includes any intersect with valid - * vmalloc area, returns 0. - * - * This function checks that addr is a valid vmalloc'ed area, and - * copy data from a buffer to the given addr. If specified range of - * [addr...addr+count) includes some valid address, data is copied from - * proper area of @buf. If there are memory holes, no copy to hole. - * IOREMAP area is treated as memory hole and no copy is done. - * - * If [addr...addr+count) doesn't includes any intersects with alive - * vm_struct area, returns 0. @buf should be kernel's buffer. - * - * Note: In usual ops, vwrite() is never necessary because the caller - * should know vmalloc() area is valid and can use memcpy(). - * This is for routines which have to access vmalloc area without - * any informaion, as /dev/kmem. + * vwrite() - write vmalloc area in a safe way. + * @buf: buffer for source data + * @addr: vm address. + * @count: number of bytes to be read. + * + * This function checks that addr is a valid vmalloc'ed area, and + * copy data from a buffer to the given addr. If specified range of + * [addr...addr+count) includes some valid address, data is copied from + * proper area of @buf. If there are memory holes, no copy to hole. + * IOREMAP area is treated as memory hole and no copy is done. + * + * If [addr...addr+count) doesn't includes any intersects with alive + * vm_struct area, returns 0. @buf should be kernel's buffer. + * + * Note: In usual ops, vwrite() is never necessary because the caller + * should know vmalloc() area is valid and can use memcpy(). + * This is for routines which have to access vmalloc area without + * any informaion, as /dev/kmem. + * + * Return: number of bytes for which addr and buf should be + * increased (same number as @count) or %0 if [addr...addr+count) + * doesn't include any intersection with valid vmalloc area */ - long vwrite(char *buf, char *addr, unsigned long count) { struct vmap_area *va; @@ -2216,20 +2321,20 @@ finished: } /** - * remap_vmalloc_range_partial - map vmalloc pages to userspace - * @vma: vma to cover - * @uaddr: target user address to start at - * @kaddr: virtual address of vmalloc kernel memory - * @size: size of map area + * remap_vmalloc_range_partial - map vmalloc pages to userspace + * @vma: vma to cover + * @uaddr: target user address to start at + * @kaddr: virtual address of vmalloc kernel memory + * @size: size of map area * - * Returns: 0 for success, -Exxx on failure + * Returns: 0 for success, -Exxx on failure * - * This function checks that @kaddr is a valid vmalloc'ed area, - * and that it is big enough to cover the range starting at - * @uaddr in @vma. Will return failure if that criteria isn't - * met. + * This function checks that @kaddr is a valid vmalloc'ed area, + * and that it is big enough to cover the range starting at + * @uaddr in @vma. Will return failure if that criteria isn't + * met. * - * Similar to remap_pfn_range() (see mm/memory.c) + * Similar to remap_pfn_range() (see mm/memory.c) */ int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr, void *kaddr, unsigned long size) @@ -2248,7 +2353,7 @@ int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr, if (!(area->flags & VM_USERMAP)) return -EINVAL; - if (kaddr + size > area->addr + area->size) + if (kaddr + size > area->addr + get_vm_area_size(area)) return -EINVAL; do { @@ -2271,18 +2376,18 @@ int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr, EXPORT_SYMBOL(remap_vmalloc_range_partial); /** - * remap_vmalloc_range - map vmalloc pages to userspace - * @vma: vma to cover (map full range of vma) - * @addr: vmalloc memory - * @pgoff: number of pages into addr before first page to map + * remap_vmalloc_range - map vmalloc pages to userspace + * @vma: vma to cover (map full range of vma) + * @addr: vmalloc memory + * @pgoff: number of pages into addr before first page to map * - * Returns: 0 for success, -Exxx on failure + * Returns: 0 for success, -Exxx on failure * - * This function checks that addr is a valid vmalloc'ed area, and - * that it is big enough to cover the vma. Will return failure if - * that criteria isn't met. + * This function checks that addr is a valid vmalloc'ed area, and + * that it is big enough to cover the vma. Will return failure if + * that criteria isn't met. * - * Similar to remap_pfn_range() (see mm/memory.c) + * Similar to remap_pfn_range() (see mm/memory.c) */ int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, unsigned long pgoff) @@ -2314,18 +2419,18 @@ static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data) } /** - * alloc_vm_area - allocate a range of kernel address space - * @size: size of the area - * @ptes: returns the PTEs for the address space + * alloc_vm_area - allocate a range of kernel address space + * @size: size of the area + * @ptes: returns the PTEs for the address space * - * Returns: NULL on failure, vm_struct on success + * Returns: NULL on failure, vm_struct on success * - * This function reserves a range of kernel address space, and - * allocates pagetables to map that range. No actual mappings - * are created. + * This function reserves a range of kernel address space, and + * allocates pagetables to map that range. No actual mappings + * are created. * - * If @ptes is non-NULL, pointers to the PTEs (in init_mm) - * allocated for the VM area are returned. + * If @ptes is non-NULL, pointers to the PTEs (in init_mm) + * allocated for the VM area are returned. */ struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes) { @@ -2751,4 +2856,3 @@ static int __init proc_vmalloc_init(void) module_init(proc_vmalloc_init); #endif - |