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Commit dd079269 authored by Borislav Petkov's avatar Borislav Petkov Committed by Thomas Gleixner
Browse files

Documentation/spec_ctrl: Do some minor cleanups 



Fix some typos, improve formulations, end sentences with a fullstop.

Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent e96f46ee

Documentation/userspace-api/spec_ctrl.rst

+12 −12
Original line number Diff line number Diff line
@@ -2,13 +2,13 @@ 
Speculation Control

===================



Quite some CPUs have speculation related misfeatures which are in fact

vulnerabilites causing data leaks in various forms even accross privilege

domains.

Quite some CPUs have speculation-related misfeatures which are in

fact vulnerabilities causing data leaks in various forms even across

privilege domains.



The kernel provides mitigation for such vulnerabilities in various

forms. Some of these mitigations are compile time configurable and some on

the kernel command line.

forms. Some of these mitigations are compile-time configurable and some

can be supplied on the kernel command line.



There is also a class of mitigations which are very expensive, but they can

be restricted to a certain set of processes or tasks in controlled
@@ -32,18 +32,18 @@ the following meaning: 
Bit  Define                Description

==== ===================== ===================================================

0    PR_SPEC_PRCTL         Mitigation can be controlled per task by

                           PR_SET_SPECULATION_CTRL

                           PR_SET_SPECULATION_CTRL.

1    PR_SPEC_ENABLE        The speculation feature is enabled, mitigation is

                           disabled

                           disabled.

2    PR_SPEC_DISABLE       The speculation feature is disabled, mitigation is

                           enabled

                           enabled.

3    PR_SPEC_FORCE_DISABLE Same as PR_SPEC_DISABLE, but cannot be undone. A

                           subsequent prctl(..., PR_SPEC_ENABLE) will fail.

==== ===================== ===================================================



If all bits are 0 the CPU is not affected by the speculation misfeature.



If PR_SPEC_PRCTL is set, then the per task control of the mitigation is

If PR_SPEC_PRCTL is set, then the per-task control of the mitigation is

available. If not set, prctl(PR_SET_SPECULATION_CTRL) for the speculation

misfeature will fail.
@@ -61,9 +61,9 @@ Common error codes 
Value   Meaning

======= =================================================================

EINVAL  The prctl is not implemented by the architecture or unused

        prctl(2) arguments are not 0

        prctl(2) arguments are not 0.



ENODEV  arg2 is selecting a not supported speculation misfeature

ENODEV  arg2 is selecting a not supported speculation misfeature.

======= =================================================================



PR_SET_SPECULATION_CTRL error codes
@@ -74,7 +74,7 @@ Value Meaning 
0       Success



ERANGE  arg3 is incorrect, i.e. it's neither PR_SPEC_ENABLE nor

        PR_SPEC_DISABLE nor PR_SPEC_FORCE_DISABLE

        PR_SPEC_DISABLE nor PR_SPEC_FORCE_DISABLE.



ENXIO   Control of the selected speculation misfeature is not possible.

        See PR_GET_SPECULATION_CTRL.