X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=mm%2Futil.c;h=55bef160b9f1484c032220b506f4ebfaeffe9a47;hb=cf0a586cf41a1779edeee7562afb5d0ab46c7cf4;hp=e14fa84ef39a2df08b2087259c110851bfcf1bcc;hpb=1a2f67b459bb7846d4a15924face63eb2683acc2;p=safe%2Fjmp%2Flinux-2.6 diff --git a/mm/util.c b/mm/util.c index e14fa84..55bef16 100644 --- a/mm/util.c +++ b/mm/util.c @@ -1,26 +1,14 @@ +#include #include #include #include #include +#include +#include #include /** - * __kzalloc - allocate memory. The memory is set to zero. - * @size: how many bytes of memory are required. - * @flags: the type of memory to allocate. - */ -void *__kzalloc(size_t size, gfp_t flags) -{ - void *ret = ____kmalloc(size, flags); - if (ret) - memset(ret, 0, size); - return ret; -} -EXPORT_SYMBOL(__kzalloc); - -/* * kstrdup - allocate space for and copy an existing string - * * @s: the string to duplicate * @gfp: the GFP mask used in the kmalloc() call when allocating memory */ @@ -33,7 +21,7 @@ char *kstrdup(const char *s, gfp_t gfp) return NULL; len = strlen(s) + 1; - buf = ____kmalloc(len, gfp); + buf = kmalloc_track_caller(len, gfp); if (buf) memcpy(buf, s, len); return buf; @@ -41,6 +29,30 @@ char *kstrdup(const char *s, gfp_t gfp) EXPORT_SYMBOL(kstrdup); /** + * kstrndup - allocate space for and copy an existing string + * @s: the string to duplicate + * @max: read at most @max chars from @s + * @gfp: the GFP mask used in the kmalloc() call when allocating memory + */ +char *kstrndup(const char *s, size_t max, gfp_t gfp) +{ + size_t len; + char *buf; + + if (!s) + return NULL; + + len = strnlen(s, max); + buf = kmalloc_track_caller(len+1, gfp); + if (buf) { + memcpy(buf, s, len); + buf[len] = '\0'; + } + return buf; +} +EXPORT_SYMBOL(kstrndup); + +/** * kmemdup - duplicate region of memory * * @src: memory region to duplicate @@ -51,16 +63,125 @@ void *kmemdup(const void *src, size_t len, gfp_t gfp) { void *p; - p = ____kmalloc(len, gfp); + p = kmalloc_track_caller(len, gfp); if (p) memcpy(p, src, len); return p; } EXPORT_SYMBOL(kmemdup); +/** + * memdup_user - duplicate memory region from user space + * + * @src: source address in user space + * @len: number of bytes to copy + * + * Returns an ERR_PTR() on failure. + */ +void *memdup_user(const void __user *src, size_t len) +{ + void *p; + + /* + * Always use GFP_KERNEL, since copy_from_user() can sleep and + * cause pagefault, which makes it pointless to use GFP_NOFS + * or GFP_ATOMIC. + */ + p = kmalloc_track_caller(len, GFP_KERNEL); + if (!p) + return ERR_PTR(-ENOMEM); + + if (copy_from_user(p, src, len)) { + kfree(p); + return ERR_PTR(-EFAULT); + } + + return p; +} +EXPORT_SYMBOL(memdup_user); + +/** + * __krealloc - like krealloc() but don't free @p. + * @p: object to reallocate memory for. + * @new_size: how many bytes of memory are required. + * @flags: the type of memory to allocate. + * + * This function is like krealloc() except it never frees the originally + * allocated buffer. Use this if you don't want to free the buffer immediately + * like, for example, with RCU. + */ +void *__krealloc(const void *p, size_t new_size, gfp_t flags) +{ + void *ret; + size_t ks = 0; + + if (unlikely(!new_size)) + return ZERO_SIZE_PTR; + + if (p) + ks = ksize(p); + + if (ks >= new_size) + return (void *)p; + + ret = kmalloc_track_caller(new_size, flags); + if (ret && p) + memcpy(ret, p, ks); + + return ret; +} +EXPORT_SYMBOL(__krealloc); + +/** + * krealloc - reallocate memory. The contents will remain unchanged. + * @p: object to reallocate memory for. + * @new_size: how many bytes of memory are required. + * @flags: the type of memory to allocate. + * + * The contents of the object pointed to are preserved up to the + * lesser of the new and old sizes. If @p is %NULL, krealloc() + * behaves exactly like kmalloc(). If @size is 0 and @p is not a + * %NULL pointer, the object pointed to is freed. + */ +void *krealloc(const void *p, size_t new_size, gfp_t flags) +{ + void *ret; + + if (unlikely(!new_size)) { + kfree(p); + return ZERO_SIZE_PTR; + } + + ret = __krealloc(p, new_size, flags); + if (ret && p != ret) + kfree(p); + + return ret; +} +EXPORT_SYMBOL(krealloc); + +/** + * kzfree - like kfree but zero memory + * @p: object to free memory of + * + * The memory of the object @p points to is zeroed before freed. + * If @p is %NULL, kzfree() does nothing. + */ +void kzfree(const void *p) +{ + size_t ks; + void *mem = (void *)p; + + if (unlikely(ZERO_OR_NULL_PTR(mem))) + return; + ks = ksize(mem); + memset(mem, 0, ks); + kfree(mem); +} +EXPORT_SYMBOL(kzfree); + /* * strndup_user - duplicate an existing string from user space - * * @s: The string to duplicate * @n: Maximum number of bytes to copy, including the trailing NUL. */ @@ -92,3 +213,58 @@ char *strndup_user(const char __user *s, long n) return p; } EXPORT_SYMBOL(strndup_user); + +#ifndef HAVE_ARCH_PICK_MMAP_LAYOUT +void arch_pick_mmap_layout(struct mm_struct *mm) +{ + mm->mmap_base = TASK_UNMAPPED_BASE; + mm->get_unmapped_area = arch_get_unmapped_area; + mm->unmap_area = arch_unmap_area; +} +#endif + +/** + * get_user_pages_fast() - pin user pages in memory + * @start: starting user address + * @nr_pages: number of pages from start to pin + * @write: whether pages will be written to + * @pages: array that receives pointers to the pages pinned. + * Should be at least nr_pages long. + * + * Attempt to pin user pages in memory without taking mm->mmap_sem. + * If not successful, it will fall back to taking the lock and + * calling get_user_pages(). + * + * Returns number of pages pinned. This may be fewer than the number + * requested. If nr_pages is 0 or negative, returns 0. If no pages + * were pinned, returns -errno. + */ +int __attribute__((weak)) get_user_pages_fast(unsigned long start, + int nr_pages, int write, struct page **pages) +{ + struct mm_struct *mm = current->mm; + int ret; + + down_read(&mm->mmap_sem); + ret = get_user_pages(current, mm, start, nr_pages, + write, 0, pages, NULL); + up_read(&mm->mmap_sem); + + return ret; +} +EXPORT_SYMBOL_GPL(get_user_pages_fast); + +/* Tracepoints definitions. */ +DEFINE_TRACE(kmalloc); +DEFINE_TRACE(kmem_cache_alloc); +DEFINE_TRACE(kmalloc_node); +DEFINE_TRACE(kmem_cache_alloc_node); +DEFINE_TRACE(kfree); +DEFINE_TRACE(kmem_cache_free); + +EXPORT_TRACEPOINT_SYMBOL(kmalloc); +EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc); +EXPORT_TRACEPOINT_SYMBOL(kmalloc_node); +EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node); +EXPORT_TRACEPOINT_SYMBOL(kfree); +EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free);