From a8749a35c39903120ec421ef2525acc8e0daa55c Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Tue, 8 Mar 2022 04:47:22 -0500 Subject: mm: vmalloc: introduce array allocation functions Linux has dozens of occurrences of vmalloc(array_size()) and vzalloc(array_size()). Allow to simplify the code by providing vmalloc_array and vcalloc, as well as the underscored variants that let the caller specify the GFP flags. Acked-by: Michal Hocko Signed-off-by: Paolo Bonzini --- mm/util.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) (limited to 'mm') diff --git a/mm/util.c b/mm/util.c index 7e43369064c8..94475abe54a0 100644 --- a/mm/util.c +++ b/mm/util.c @@ -647,6 +647,56 @@ void *kvrealloc(const void *p, size_t oldsize, size_t newsize, gfp_t flags) } EXPORT_SYMBOL(kvrealloc); +/** + * __vmalloc_array - allocate memory for a virtually contiguous array. + * @n: number of elements. + * @size: element size. + * @flags: the type of memory to allocate (see kmalloc). + */ +void *__vmalloc_array(size_t n, size_t size, gfp_t flags) +{ + size_t bytes; + + if (unlikely(check_mul_overflow(n, size, &bytes))) + return NULL; + return __vmalloc(bytes, flags); +} +EXPORT_SYMBOL(__vmalloc_array); + +/** + * vmalloc_array - allocate memory for a virtually contiguous array. + * @n: number of elements. + * @size: element size. + */ +void *vmalloc_array(size_t n, size_t size) +{ + return __vmalloc_array(n, size, GFP_KERNEL); +} +EXPORT_SYMBOL(vmalloc_array); + +/** + * __vcalloc - allocate and zero memory for a virtually contiguous array. + * @n: number of elements. + * @size: element size. + * @flags: the type of memory to allocate (see kmalloc). + */ +void *__vcalloc(size_t n, size_t size, gfp_t flags) +{ + return __vmalloc_array(n, size, flags | __GFP_ZERO); +} +EXPORT_SYMBOL(__vcalloc); + +/** + * vcalloc - allocate and zero memory for a virtually contiguous array. + * @n: number of elements. + * @size: element size. + */ +void *vcalloc(size_t n, size_t size) +{ + return __vmalloc_array(n, size, GFP_KERNEL | __GFP_ZERO); +} +EXPORT_SYMBOL(vcalloc); + /* Neutral page->mapping pointer to address_space or anon_vma or other */ void *page_rmapping(struct page *page) { -- cgit v1.2.3 From 3000f2e2fc855664c28d3e6a47e0373737974eb4 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Tue, 8 Mar 2022 05:02:21 -0500 Subject: mm: use vmalloc_array and vcalloc for array allocations Instead of using array_size or just a multiply, use a function that takes care of both the multiplication and the overflow checks. Acked-by: Michal Hocko Signed-off-by: Paolo Bonzini --- mm/percpu-stats.c | 2 +- mm/swap_cgroup.c | 4 +--- 2 files changed, 2 insertions(+), 4 deletions(-) (limited to 'mm') diff --git a/mm/percpu-stats.c b/mm/percpu-stats.c index c6bd092ff7a3..dd3590dfc23d 100644 --- a/mm/percpu-stats.c +++ b/mm/percpu-stats.c @@ -144,7 +144,7 @@ alloc_buffer: spin_unlock_irq(&pcpu_lock); /* there can be at most this many free and allocated fragments */ - buffer = vmalloc(array_size(sizeof(int), (2 * max_nr_alloc + 1))); + buffer = vmalloc_array(2 * max_nr_alloc + 1, sizeof(int)); if (!buffer) return -ENOMEM; diff --git a/mm/swap_cgroup.c b/mm/swap_cgroup.c index 7f34343c075a..5a9442979a18 100644 --- a/mm/swap_cgroup.c +++ b/mm/swap_cgroup.c @@ -167,14 +167,12 @@ unsigned short lookup_swap_cgroup_id(swp_entry_t ent) int swap_cgroup_swapon(int type, unsigned long max_pages) { void *array; - unsigned long array_size; unsigned long length; struct swap_cgroup_ctrl *ctrl; length = DIV_ROUND_UP(max_pages, SC_PER_PAGE); - array_size = length * sizeof(void *); - array = vzalloc(array_size); + array = vcalloc(length, sizeof(void *)); if (!array) goto nomem; -- cgit v1.2.3