Thread (1 message) 1 message, 1 author, 2017-03-28

[PATCH 1/1] apparmor: use SHASH_DESC_ON_STACK

From: Nicolas Iooss <hidden>
Date: 2017-03-28 21:10:43
Also in: lkml

Hello,
I sent the following patch three weeks ago and have not got any reply.
Could you please review it?

Thanks,
Nicolas

On Sun, Mar 5, 2017 at 3:30 PM, Nicolas Iooss
[off-list ref] wrote:
quoted hunk
When building the kernel with clang, the compiler fails to build
security/apparmor/crypto.c with the following error:

    security/apparmor/crypto.c:36:8: error: fields must have a constant
    size: 'variable length array in structure' extension will never be
    supported
                    char ctx[crypto_shash_descsize(apparmor_tfm)];
                         ^

Since commit a0a77af14117 ("crypto: LLVMLinux: Add macro to remove use
of VLAIS in crypto code"), include/crypto/hash.h defines
SHASH_DESC_ON_STACK to work around this issue. Use it in aa_calc_hash()
and aa_calc_profile_hash().

Signed-off-by: Nicolas Iooss <redacted>
---
 security/apparmor/crypto.c | 32 +++++++++++++-------------------
 1 file changed, 13 insertions(+), 19 deletions(-)
diff --git a/security/apparmor/crypto.c b/security/apparmor/crypto.c
index de8dc78b6144..136f2a047836 100644
--- a/security/apparmor/crypto.c
+++ b/security/apparmor/crypto.c
@@ -31,10 +31,7 @@ unsigned int aa_hash_size(void)

 char *aa_calc_hash(void *data, size_t len)
 {
-       struct {
-               struct shash_desc shash;
-               char ctx[crypto_shash_descsize(apparmor_tfm)];
-       } desc;
+       SHASH_DESC_ON_STACK(desc, apparmor_tfm);
        char *hash = NULL;
        int error = -ENOMEM;
@@ -45,16 +42,16 @@ char *aa_calc_hash(void *data, size_t len)
        if (!hash)
                goto fail;

-       desc.shash.tfm = apparmor_tfm;
-       desc.shash.flags = 0;
+       desc->tfm = apparmor_tfm;
+       desc->flags = 0;

-       error = crypto_shash_init(&desc.shash);
+       error = crypto_shash_init(desc);
        if (error)
                goto fail;
-       error = crypto_shash_update(&desc.shash, (u8 *) data, len);
+       error = crypto_shash_update(desc, (u8 *) data, len);
        if (error)
                goto fail;
-       error = crypto_shash_final(&desc.shash, hash);
+       error = crypto_shash_final(desc, hash);
        if (error)
                goto fail;
@@ -69,10 +66,7 @@ char *aa_calc_hash(void *data, size_t len)
 int aa_calc_profile_hash(struct aa_profile *profile, u32 version, void *start,
                         size_t len)
 {
-       struct {
-               struct shash_desc shash;
-               char ctx[crypto_shash_descsize(apparmor_tfm)];
-       } desc;
+       SHASH_DESC_ON_STACK(desc, apparmor_tfm);
        int error = -ENOMEM;
        __le32 le32_version = cpu_to_le32(version);
@@ -86,19 +80,19 @@ int aa_calc_profile_hash(struct aa_profile *profile, u32 version, void *start,
        if (!profile->hash)
                goto fail;

-       desc.shash.tfm = apparmor_tfm;
-       desc.shash.flags = 0;
+       desc->tfm = apparmor_tfm;
+       desc->flags = 0;

-       error = crypto_shash_init(&desc.shash);
+       error = crypto_shash_init(desc);
        if (error)
                goto fail;
-       error = crypto_shash_update(&desc.shash, (u8 *) &le32_version, 4);
+       error = crypto_shash_update(desc, (u8 *) &le32_version, 4);
        if (error)
                goto fail;
-       error = crypto_shash_update(&desc.shash, (u8 *) start, len);
+       error = crypto_shash_update(desc, (u8 *) start, len);
        if (error)
                goto fail;
-       error = crypto_shash_final(&desc.shash, profile->hash);
+       error = crypto_shash_final(desc, profile->hash);
        if (error)
                goto fail;

--
2.11.1
--
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