Messages in this thread Patch in this message | | | From | ira.weiny@intel ... | Subject | [PATCH] x86: Remove unnecessary kmap() from sgx_ioc_enclave_init() | Date | Thu, 28 Jan 2021 16:14:59 -0800 |
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From: Ira Weiny <ira.weiny@intel.com>
There is no reason to alloc a page and kmap it to store this temporary data from the user. This is especially true when we are trying to remove kmap usages. Also placing the token pointer 1/2 way into the page is fragile.
Replace this allocation with two kzalloc()'s which also removes the need for the memset().
Signed-off-by: Ira Weiny <ira.weiny@intel.com> --- arch/x86/kernel/cpu/sgx/ioctl.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c index 90a5caf76939..9c9019760585 100644 --- a/arch/x86/kernel/cpu/sgx/ioctl.c +++ b/arch/x86/kernel/cpu/sgx/ioctl.c @@ -604,7 +604,6 @@ static long sgx_ioc_enclave_init(struct sgx_encl *encl, void __user *arg) { struct sgx_sigstruct *sigstruct; struct sgx_enclave_init init_arg; - struct page *initp_page; void *token; int ret; @@ -615,13 +614,15 @@ static long sgx_ioc_enclave_init(struct sgx_encl *encl, void __user *arg) if (copy_from_user(&init_arg, arg, sizeof(init_arg))) return -EFAULT; - initp_page = alloc_page(GFP_KERNEL); - if (!initp_page) + sigstruct = kzalloc(sizeof(*sigstruct), GFP_KERNEL); + if (!sigstruct) return -ENOMEM; - sigstruct = kmap(initp_page); - token = (void *)((unsigned long)sigstruct + PAGE_SIZE / 2); - memset(token, 0, SGX_LAUNCH_TOKEN_SIZE); + token = kzalloc(SGX_LAUNCH_TOKEN_SIZE, GFP_KERNEL); + if (!token) { + ret = -ENOMEM; + goto free_sigstruct; + } if (copy_from_user(sigstruct, (void __user *)init_arg.sigstruct, sizeof(*sigstruct))) { @@ -645,8 +646,9 @@ static long sgx_ioc_enclave_init(struct sgx_encl *encl, void __user *arg) ret = sgx_encl_init(encl, sigstruct, token); out: - kunmap(initp_page); - __free_page(initp_page); + kfree(token); +free_sigstruct: + kfree(sigstruct); return ret; } -- 2.28.0.rc0.12.gb6a658bd00c9
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