From 26b02a1f9670862c51b3ff63a6128589866f5c71 Mon Sep 17 00:00:00 2001 From: Sasha Levin Date: Tue, 14 Apr 2015 15:44:59 -0700 Subject: [PATCH] mm: cma: allocation trigger Provides a userspace interface to trigger a CMA allocation. Usage: echo [pages] > alloc This would provide testing/fuzzing access to the CMA allocation paths. Signed-off-by: Sasha Levin Acked-by: Joonsoo Kim Cc: Marek Szyprowski Cc: Laura Abbott Cc: Konrad Rzeszutek Wilk Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/cma.c | 6 ++++++ mm/cma.h | 4 ++++ mm/cma_debug.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++- 3 files changed, 63 insertions(+), 1 deletion(-) diff --git a/mm/cma.c b/mm/cma.c index 2655b8191656..7f6045420925 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -123,6 +123,12 @@ static int __init cma_activate_area(struct cma *cma) } while (--i); mutex_init(&cma->lock); + +#ifdef CONFIG_CMA_DEBUGFS + INIT_HLIST_HEAD(&cma->mem_head); + spin_lock_init(&cma->mem_head_lock); +#endif + return 0; err: diff --git a/mm/cma.h b/mm/cma.h index 4141887bbfb0..1132d733556d 100644 --- a/mm/cma.h +++ b/mm/cma.h @@ -7,6 +7,10 @@ struct cma { unsigned long *bitmap; unsigned int order_per_bit; /* Order of pages represented by one bit */ struct mutex lock; +#ifdef CONFIG_CMA_DEBUGFS + struct hlist_head mem_head; + spinlock_t mem_head_lock; +#endif }; extern struct cma cma_areas[MAX_CMA_AREAS]; diff --git a/mm/cma_debug.c b/mm/cma_debug.c index 3af2de6d4e5f..f3baa413ab33 100644 --- a/mm/cma_debug.c +++ b/mm/cma_debug.c @@ -7,9 +7,18 @@ #include #include +#include +#include +#include #include "cma.h" +struct cma_mem { + struct hlist_node node; + struct page *p; + unsigned long n; +}; + static struct dentry *cma_debugfs_root; static int cma_debugfs_get(void *data, u64 *val) @@ -23,6 +32,46 @@ static int cma_debugfs_get(void *data, u64 *val) DEFINE_SIMPLE_ATTRIBUTE(cma_debugfs_fops, cma_debugfs_get, NULL, "%llu\n"); +static void cma_add_to_cma_mem_list(struct cma *cma, struct cma_mem *mem) +{ + spin_lock(&cma->mem_head_lock); + hlist_add_head(&mem->node, &cma->mem_head); + spin_unlock(&cma->mem_head_lock); +} + +static int cma_alloc_mem(struct cma *cma, int count) +{ + struct cma_mem *mem; + struct page *p; + + mem = kzalloc(sizeof(*mem), GFP_KERNEL); + if (!mem) + return -ENOMEM; + + p = cma_alloc(cma, count, CONFIG_CMA_ALIGNMENT); + if (!p) { + kfree(mem); + return -ENOMEM; + } + + mem->p = p; + mem->n = count; + + cma_add_to_cma_mem_list(cma, mem); + + return 0; +} + +static int cma_alloc_write(void *data, u64 val) +{ + int pages = val; + struct cma *cma = data; + + return cma_alloc_mem(cma, pages); +} + +DEFINE_SIMPLE_ATTRIBUTE(cma_alloc_fops, NULL, cma_alloc_write, "%llu\n"); + static void cma_debugfs_add_one(struct cma *cma, int idx) { struct dentry *tmp; @@ -33,12 +82,15 @@ static void cma_debugfs_add_one(struct cma *cma, int idx) tmp = debugfs_create_dir(name, cma_debugfs_root); + debugfs_create_file("alloc", S_IWUSR, cma_debugfs_root, cma, + &cma_alloc_fops); + debugfs_create_file("base_pfn", S_IRUGO, tmp, &cma->base_pfn, &cma_debugfs_fops); debugfs_create_file("count", S_IRUGO, tmp, &cma->count, &cma_debugfs_fops); debugfs_create_file("order_per_bit", S_IRUGO, tmp, - &cma->order_per_bit, &cma_debugfs_fops); + &cma->order_per_bit, &cma_debugfs_fops); u32s = DIV_ROUND_UP(cma_bitmap_maxno(cma), BITS_PER_BYTE * sizeof(u32)); debugfs_create_u32_array("bitmap", S_IRUGO, tmp, (u32*)cma->bitmap, u32s); -- 2.20.1