| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <CAFA6WYONU8YdJuFSX_Mv8soKgr57DeZT6j7ywJ2oni8vHs35ug@mail.gmail.com>
Date: Thu, 31 Oct 2019 18:39:45 +0530
From: Sumit Garg <sumit.garg@...aro.org>
To: Volodymyr Babchuk <Volodymyr_Babchuk@...m.com>,
Jens Wiklander <jens.wiklander@...aro.org>
Cc: "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"tee-dev @ lists . linaro . org" <tee-dev@...ts.linaro.org>
Subject: Re: [Tee-dev] [PATCH v3] optee: allow to work without static shared memory
Hi Volodymyr, Jens,
On Mon, 11 Mar 2019 at 18:34, Volodymyr Babchuk
<Volodymyr_Babchuk@...m.com> wrote:
>
> From: Volodymyr Babchuk <vlad.babchuk@...il.com>
>
> On virtualized systems it is possible that OP-TEE will provide
> only dynamic shared memory support. So it is fine to boot
> without static SHM enabled if dymanic one is supported.
>
> Signed-off-by: Volodymyr Babchuk <vlad.babchuk@...il.com>
> ---
Is this patch well tested?
This patch seems to broke "tee_shm_alloc()" API for all kernel
internal / user-space clients in case dynamic shared memory is enabled
in OP-TEE (capability: OPTEE_SMC_SEC_CAP_DYNAMIC_SHM is set).
How are kernel buffers allocated from "dmabuf_mgr" as per this patch
registered with OP-TEE?
Note here that "priv_mgr" seems to work well as OP-TEE provides a hook
to map the buffers returned during RPC calls into registered shm
space.
I think the correct way to enable intended feature as per description
of the patch would be to add an additional call to
"optee_shm_register()" during allocation from "dmabuf_mgr". So I have
proposed a fix patch here [1]. Please have a look.
[1] https://lkml.org/lkml/2019/10/31/382
Regards,
Sumit
>
> Changes from V2:
> - rebased onto upstream
>
> drivers/tee/optee/core.c | 80 ++++++++++++++++++++++++----------------
> 1 file changed, 49 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
> index 0842b6e6af82..48963eab32f5 100644
> --- a/drivers/tee/optee/core.c
> +++ b/drivers/tee/optee/core.c
> @@ -419,9 +419,35 @@ static bool optee_msg_exchange_capabilities(optee_invoke_fn *invoke_fn,
> return true;
> }
>
> +static struct tee_shm_pool *optee_config_dyn_shm(void)
> +{
> + struct tee_shm_pool_mgr *priv_mgr;
> + struct tee_shm_pool_mgr *dmabuf_mgr;
> + void *rc;
> +
> + rc = optee_shm_pool_alloc_pages();
> + if (IS_ERR(rc))
> + return rc;
> + priv_mgr = rc;
> +
> + rc = optee_shm_pool_alloc_pages();
> + if (IS_ERR(rc)) {
> + tee_shm_pool_mgr_destroy(priv_mgr);
> + return rc;
> + }
> + dmabuf_mgr = rc;
> +
> + rc = tee_shm_pool_alloc(priv_mgr, dmabuf_mgr);
> + if (IS_ERR(rc)) {
> + tee_shm_pool_mgr_destroy(priv_mgr);
> + tee_shm_pool_mgr_destroy(dmabuf_mgr);
> + }
> +
> + return rc;
> +}
> +
> static struct tee_shm_pool *
> -optee_config_shm_memremap(optee_invoke_fn *invoke_fn, void **memremaped_shm,
> - u32 sec_caps)
> +optee_config_shm_memremap(optee_invoke_fn *invoke_fn, void **memremaped_shm)
> {
> union {
> struct arm_smccc_res smccc;
> @@ -436,10 +462,11 @@ optee_config_shm_memremap(optee_invoke_fn *invoke_fn, void **memremaped_shm,
> struct tee_shm_pool_mgr *priv_mgr;
> struct tee_shm_pool_mgr *dmabuf_mgr;
> void *rc;
> + const int sz = OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE;
>
> invoke_fn(OPTEE_SMC_GET_SHM_CONFIG, 0, 0, 0, 0, 0, 0, 0, &res.smccc);
> if (res.result.status != OPTEE_SMC_RETURN_OK) {
> - pr_info("shm service not available\n");
> + pr_err("static shm service not available\n");
> return ERR_PTR(-ENOENT);
> }
>
> @@ -465,28 +492,15 @@ optee_config_shm_memremap(optee_invoke_fn *invoke_fn, void **memremaped_shm,
> }
> vaddr = (unsigned long)va;
>
> - /*
> - * If OP-TEE can work with unregistered SHM, we will use own pool
> - * for private shm
> - */
> - if (sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_SHM) {
> - rc = optee_shm_pool_alloc_pages();
> - if (IS_ERR(rc))
> - goto err_memunmap;
> - priv_mgr = rc;
> - } else {
> - const size_t sz = OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE;
> -
> - rc = tee_shm_pool_mgr_alloc_res_mem(vaddr, paddr, sz,
> - 3 /* 8 bytes aligned */);
> - if (IS_ERR(rc))
> - goto err_memunmap;
> - priv_mgr = rc;
> -
> - vaddr += sz;
> - paddr += sz;
> - size -= sz;
> - }
> + rc = tee_shm_pool_mgr_alloc_res_mem(vaddr, paddr, sz,
> + 3 /* 8 bytes aligned */);
> + if (IS_ERR(rc))
> + goto err_memunmap;
> + priv_mgr = rc;
> +
> + vaddr += sz;
> + paddr += sz;
> + size -= sz;
>
> rc = tee_shm_pool_mgr_alloc_res_mem(vaddr, paddr, size, PAGE_SHIFT);
> if (IS_ERR(rc))
> @@ -552,7 +566,7 @@ static optee_invoke_fn *get_invoke_func(struct device_node *np)
> static struct optee *optee_probe(struct device_node *np)
> {
> optee_invoke_fn *invoke_fn;
> - struct tee_shm_pool *pool;
> + struct tee_shm_pool *pool = ERR_PTR(-EINVAL);
> struct optee *optee = NULL;
> void *memremaped_shm = NULL;
> struct tee_device *teedev;
> @@ -581,13 +595,17 @@ static struct optee *optee_probe(struct device_node *np)
> }
>
> /*
> - * We have no other option for shared memory, if secure world
> - * doesn't have any reserved memory we can use we can't continue.
> + * Try to use dynamic shared memory if possible
> */
> - if (!(sec_caps & OPTEE_SMC_SEC_CAP_HAVE_RESERVED_SHM))
> - return ERR_PTR(-EINVAL);
> + if (sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_SHM)
> + pool = optee_config_dyn_shm();
> +
> + /*
> + * If dynamic shared memory is not available or failed - try static one
> + */
> + if (IS_ERR(pool) && (sec_caps & OPTEE_SMC_SEC_CAP_HAVE_RESERVED_SHM))
> + pool = optee_config_shm_memremap(invoke_fn, &memremaped_shm);
>
> - pool = optee_config_shm_memremap(invoke_fn, &memremaped_shm, sec_caps);
> if (IS_ERR(pool))
> return (void *)pool;
>
> --
> 2.21.0
> _______________________________________________
> Tee-dev mailing list
> Tee-dev@...ts.linaro.org
> https://lists.linaro.org/mailman/listinfo/tee-dev
Powered by blists - more mailing lists