2017-03-05 14:38:41

by Nicolas Iooss

Subject: [PATCH 1/1] apparmor: use SHASH_DESC_ON_STACK

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 <[email protected]>
---
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

2017-03-28 21:10:43

by Nicolas Iooss

Subject: Re: [PATCH 1/1] apparmor: use SHASH_DESC_ON_STACK

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
<[email protected]> wrote:
> 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 <[email protected]>
> ---
> 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
>

2017-03-28 22:03:29

by John Johansen

Subject: Re: [PATCH 1/1] apparmor: use SHASH_DESC_ON_STACK

On 03/05/2017 06:30 AM, Nicolas Iooss wrote:
> 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 <[email protected]>
Acked-by: John Johansen <[email protected]>

I'll pull it into my tree and send it up this week


> ---
> 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;
>
>