diff options
| author | Ira Weiny <ira.weiny@intel.com> | 2021-03-24 11:22:46 -0700 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2021-03-25 09:50:32 +0100 |
| commit | 633b0616cfe085679471a4c0fae02e8c3a1a9866 (patch) | |
| tree | 908486d7ae417a5619a1fbb3a529136d3defcc75 /arch | |
| parent | f33dece70e11ce82a09cb1ea2d7c32347b82c67e (diff) | |
x86/sgx: Remove unnecessary kmap() from sgx_ioc_enclave_init()
kmap() is inefficient and is being replaced by kmap_local_page(), if
possible. There is no readily apparent reason why initp_page needs to be
allocated and kmap'ed() except that 'sigstruct' needs to be page-aligned
and 'token' 512 byte-aligned.
Rather than change it to kmap_local_page(), use kmalloc() instead
because kmalloc() can give this alignment when allocating PAGE_SIZE
bytes.
Remove the alloc_page()/kmap() and replace with kmalloc(PAGE_SIZE, ...)
to get a page aligned kernel address.
In addition, add a comment to document the alignment requirements so that
others don't attempt to 'fix' this again.
[ bp: Massage commit message. ]
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210324182246.2484875-1-ira.weiny@intel.com
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/cpu/sgx/ioctl.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c index 90a5caf76939..2e10367ea66c 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; @@ -615,11 +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' must be on a page boundary and 'token' on a 512 byte + * boundary. kmalloc() will give this alignment when allocating + * PAGE_SIZE bytes. + */ + sigstruct = kmalloc(PAGE_SIZE, 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); @@ -645,8 +648,7 @@ 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(sigstruct); return ret; } |