The patch titled
eCryptfs: Reduce stack usage in ecryptfs_generate_key_packet_set()
has been added to the -mm tree. Its filename is
ecryptfs-reduce-stack-usage-in-ecryptfs_generate_key_packet_set.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: eCryptfs: Reduce stack usage in ecryptfs_generate_key_packet_set()
From: Michael Halcrow <mhalcrow@xxxxxxxxxx>
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 <mhalcrow@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/ecryptfs/ecryptfs_kernel.h | 1 +
fs/ecryptfs/keystore.c | 26 ++++++++++++++++++--------
fs/ecryptfs/main.c | 5 +++++
3 files changed, 24 insertions(+), 8 deletions(-)
diff -puN fs/ecryptfs/ecryptfs_kernel.h~ecryptfs-reduce-stack-usage-in-ecryptfs_generate_key_packet_set fs/ecryptfs/ecryptfs_kernel.h
--- a/fs/ecryptfs/ecryptfs_kernel.h~ecryptfs-reduce-stack-usage-in-ecryptfs_generate_key_packet_set
+++ a/fs/ecryptfs/ecryptfs_kernel.h
@@ -467,6 +467,7 @@ extern struct kmem_cache *ecryptfs_heade
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 -puN fs/ecryptfs/keystore.c~ecryptfs-reduce-stack-usage-in-ecryptfs_generate_key_packet_set fs/ecryptfs/keystore.c
--- a/fs/ecryptfs/keystore.c~ecryptfs-reduce-stack-usage-in-ecryptfs_generate_key_packet_set
+++ a/fs/ecryptfs/keystore.c
@@ -1639,6 +1639,8 @@ 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
@@ -1665,50 +1667,55 @@ ecryptfs_generate_key_packet_set(char *d
&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();
@@ -1718,6 +1725,9 @@ ecryptfs_generate_key_packet_set(char *d
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 -puN fs/ecryptfs/main.c~ecryptfs-reduce-stack-usage-in-ecryptfs_generate_key_packet_set fs/ecryptfs/main.c
--- a/fs/ecryptfs/main.c~ecryptfs-reduce-stack-usage-in-ecryptfs_generate_key_packet_set
+++ a/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)
_
Patches currently in -mm which might be from mhalcrow@xxxxxxxxxx are
origin.patch
git-unionfs.patch
ecryptfs-convert-lookup_one_len-to-lookup_one_len_nd.patch
ecryptfs-reduce-stack-usage-in-ecryptfs_generate_key_packet_set.patch
-
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