[tip: x86/sgx] x86/sgx: SGX documentation fixes

From: tip-bot2 for Reinette Chatre
Date: Tue Nov 16 2021 - 18:39:41 EST


The following commit has been merged into the x86/sgx branch of tip:

Commit-ID: c4d61a51f055928021af32f34853eba8a05be41d
Gitweb: https://git.kernel.org/tip/c4d61a51f055928021af32f34853eba8a05be41d
Author: Reinette Chatre <reinette.chatre@xxxxxxxxx>
AuthorDate: Fri, 29 Oct 2021 10:49:56 -07:00
Committer: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
CommitterDate: Tue, 16 Nov 2021 13:45:14 -08:00

x86/sgx: SGX documentation fixes

SGX documentation fixes are:

* Remove capitalization from regular words in the middle of a sentence.
* Remove punctuation found in the middle of a sentence.
* Fix name of SGX daemon to consistently be ksgxd.
* Fix typo of SGX instruction: ENIT -> EINIT

Signed-off-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Reviewed-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
Link: https://lkml.kernel.org/r/ab99a87368eef69e3fb96f073368becff3eff874.1635529506.git.reinette.chatre@xxxxxxxxx
---
Documentation/x86/sgx.rst | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/Documentation/x86/sgx.rst b/Documentation/x86/sgx.rst
index a608f66..265568a 100644
--- a/Documentation/x86/sgx.rst
+++ b/Documentation/x86/sgx.rst
@@ -10,7 +10,7 @@ Overview
Software Guard eXtensions (SGX) hardware enables for user space applications
to set aside private memory regions of code and data:

-* Privileged (ring-0) ENCLS functions orchestrate the construction of the.
+* Privileged (ring-0) ENCLS functions orchestrate the construction of the
regions.
* Unprivileged (ring-3) ENCLU functions allow an application to enter and
execute inside the regions.
@@ -91,7 +91,7 @@ In addition to the traditional compiler and linker build process, SGX has a
separate enclave “build” process. Enclaves must be built before they can be
executed (entered). The first step in building an enclave is opening the
**/dev/sgx_enclave** device. Since enclave memory is protected from direct
-access, special privileged instructions are Then used to copy data into enclave
+access, special privileged instructions are then used to copy data into enclave
pages and establish enclave page permissions.

.. kernel-doc:: arch/x86/kernel/cpu/sgx/ioctl.c
@@ -126,13 +126,13 @@ the need to juggle signal handlers.
ksgxd
=====

-SGX support includes a kernel thread called *ksgxwapd*.
+SGX support includes a kernel thread called *ksgxd*.

EPC sanitization
----------------

ksgxd is started when SGX initializes. Enclave memory is typically ready
-For use when the processor powers on or resets. However, if SGX has been in
+for use when the processor powers on or resets. However, if SGX has been in
use since the reset, enclave pages may be in an inconsistent state. This might
occur after a crash and kexec() cycle, for instance. At boot, ksgxd
reinitializes all enclave pages so that they can be allocated and re-used.
@@ -147,7 +147,7 @@ Page reclaimer

Similar to the core kswapd, ksgxd, is responsible for managing the
overcommitment of enclave memory. If the system runs out of enclave memory,
-*ksgxwapd* “swaps” enclave memory to normal memory.
+*ksgxd* “swaps” enclave memory to normal memory.

Launch Control
==============
@@ -156,7 +156,7 @@ SGX provides a launch control mechanism. After all enclave pages have been
copied, kernel executes EINIT function, which initializes the enclave. Only after
this the CPU can execute inside the enclave.

-ENIT function takes an RSA-3072 signature of the enclave measurement. The function
+EINIT function takes an RSA-3072 signature of the enclave measurement. The function
checks that the measurement is correct and signature is signed with the key
hashed to the four **IA32_SGXLEPUBKEYHASH{0, 1, 2, 3}** MSRs representing the
SHA256 of a public key.
@@ -184,7 +184,7 @@ CPUs starting from Icelake use Total Memory Encryption (TME) in the place of
MEE. TME-based SGX implementations do not have an integrity Merkle tree, which
means integrity and replay-attacks are not mitigated. B, it includes
additional changes to prevent cipher text from being returned and SW memory
-aliases from being Created.
+aliases from being created.

DMA to enclave memory is blocked by range registers on both MEE and TME systems
(SDM section 41.10).