From eb95e7ffa50fa2921ef1845a5dcb2fe5b21e83a2 Mon Sep 17 00:00:00 2001 From: Michael Halcrow Date: Fri, 16 Feb 2007 01:28:40 -0800 Subject: [PATCH] [PATCH] eCryptfs: Reduce stack usage in ecryptfs_generate_key_packet_set() eCryptfs is gobbling a lot of stack in ecryptfs_generate_key_packet_set() because it allocates a temporary memory-hungry ecryptfs_key_record struct. This patch introduces a new kmem_cache for that struct and converts ecryptfs_generate_key_packet_set() to use it. Signed-off-by: Michael Halcrow Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ecryptfs/ecryptfs_kernel.h | 1 + fs/ecryptfs/keystore.c | 26 ++++++++++++++++++-------- fs/ecryptfs/main.c | 5 +++++ 3 files changed, 24 insertions(+), 8 deletions(-) diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h index b3609b7cdf1..403e3bad145 100644 --- a/fs/ecryptfs/ecryptfs_kernel.h +++ b/fs/ecryptfs/ecryptfs_kernel.h @@ -467,6 +467,7 @@ extern struct kmem_cache *ecryptfs_header_cache_1; extern struct kmem_cache *ecryptfs_header_cache_2; extern struct kmem_cache *ecryptfs_xattr_cache; extern struct kmem_cache *ecryptfs_lower_page_cache; +extern struct kmem_cache *ecryptfs_key_record_cache; int ecryptfs_interpose(struct dentry *hidden_dentry, struct dentry *this_dentry, struct super_block *sb, diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c index 81156e95ef8..b550dea8eee 100644 --- a/fs/ecryptfs/keystore.c +++ b/fs/ecryptfs/keystore.c @@ -1638,6 +1638,8 @@ out: return rc; } +struct kmem_cache *ecryptfs_key_record_cache; + /** * ecryptfs_generate_key_packet_set * @dest: Virtual address from which to write the key record set @@ -1664,50 +1666,55 @@ ecryptfs_generate_key_packet_set(char *dest_base, &ecryptfs_superblock_to_private( ecryptfs_dentry->d_sb)->mount_crypt_stat; size_t written; - struct ecryptfs_key_record key_rec; + struct ecryptfs_key_record *key_rec; int rc = 0; (*len) = 0; + key_rec = kmem_cache_alloc(ecryptfs_key_record_cache, GFP_KERNEL); + if (!key_rec) { + rc = -ENOMEM; + goto out; + } if (mount_crypt_stat->global_auth_tok) { auth_tok = mount_crypt_stat->global_auth_tok; if (auth_tok->token_type == ECRYPTFS_PASSWORD) { rc = write_tag_3_packet((dest_base + (*len)), max, auth_tok, - crypt_stat, &key_rec, + crypt_stat, key_rec, &written); if (rc) { ecryptfs_printk(KERN_WARNING, "Error " "writing tag 3 packet\n"); - goto out; + goto out_free; } (*len) += written; /* Write auth tok signature packet */ rc = write_tag_11_packet( (dest_base + (*len)), (max - (*len)), - key_rec.sig, ECRYPTFS_SIG_SIZE, &written); + key_rec->sig, ECRYPTFS_SIG_SIZE, &written); if (rc) { ecryptfs_printk(KERN_ERR, "Error writing " "auth tok signature packet\n"); - goto out; + goto out_free; } (*len) += written; } else if (auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) { rc = write_tag_1_packet(dest_base + (*len), max, auth_tok, crypt_stat,mount_crypt_stat, - &key_rec, &written); + key_rec, &written); if (rc) { ecryptfs_printk(KERN_WARNING, "Error " "writing tag 1 packet\n"); - goto out; + goto out_free; } (*len) += written; } else { ecryptfs_printk(KERN_WARNING, "Unsupported " "authentication token type\n"); rc = -EINVAL; - goto out; + goto out_free; } } else BUG(); @@ -1717,6 +1724,9 @@ ecryptfs_generate_key_packet_set(char *dest_base, ecryptfs_printk(KERN_ERR, "Error writing boundary byte\n"); rc = -EIO; } + +out_free: + kmem_cache_free(ecryptfs_key_record_cache, key_rec); out: if (rc) (*len) = 0; diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c index 26fe405a576..80044d196fe 100644 --- a/fs/ecryptfs/main.c +++ b/fs/ecryptfs/main.c @@ -651,6 +651,11 @@ static struct ecryptfs_cache_info { .name = "ecryptfs_lower_page_cache", .size = PAGE_CACHE_SIZE, }, + { + .cache = &ecryptfs_key_record_cache, + .name = "ecryptfs_key_record_cache", + .size = sizeof(struct ecryptfs_key_record), + }, }; static void ecryptfs_free_kmem_caches(void) -- 2.41.1