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authorJason Liu <jason.hui.liu@nxp.com>2019-12-16 10:22:36 +0800
committerJason Liu <jason.hui.liu@nxp.com>2019-12-16 14:38:10 +0800
commit622141309f6e4288a4cb2f6e697c2bcbf4963fed (patch)
tree83fb3635cf123b2de8c280d6ba510b73d2532476 /Documentation/admin-guide
parentc85bf6f6903ad154848fee495b3b34c3cde86f6c (diff)
parentf7688b48ac46e9a669e279f1bc167722d5141eda (diff)
Merge linux-5.4.y tag 'v5.4.3' into lf-5.4.y
This is the 5.4.3 stable release Conflicts: drivers/cpufreq/imx-cpufreq-dt.c drivers/spi/spi-fsl-qspi.c The conflict is very minor, fixed it when do the merge. The imx-cpufreq-dt.c is just one line code-style change, using upstream one, no any function change. The spi-fsl-qspi.c has minor conflicts when merge upstream fixes: c69b17da53b2 spi: spi-fsl-qspi: Clear TDH bits in FLSHCR register After merge, basic boot sanity test and basic qspi test been done on i.mx Signed-off-by: Jason Liu <jason.hui.liu@nxp.com>
Diffstat (limited to 'Documentation/admin-guide')
-rw-r--r--Documentation/admin-guide/hw-vuln/mds.rst7
-rw-r--r--Documentation/admin-guide/hw-vuln/tsx_async_abort.rst5
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt11
3 files changed, 20 insertions, 3 deletions
diff --git a/Documentation/admin-guide/hw-vuln/mds.rst b/Documentation/admin-guide/hw-vuln/mds.rst
index e3a796c0d3a2..2d19c9f4c1fe 100644
--- a/Documentation/admin-guide/hw-vuln/mds.rst
+++ b/Documentation/admin-guide/hw-vuln/mds.rst
@@ -265,8 +265,11 @@ time with the option "mds=". The valid arguments for this option are:
============ =============================================================
-Not specifying this option is equivalent to "mds=full".
-
+Not specifying this option is equivalent to "mds=full". For processors
+that are affected by both TAA (TSX Asynchronous Abort) and MDS,
+specifying just "mds=off" without an accompanying "tsx_async_abort=off"
+will have no effect as the same mitigation is used for both
+vulnerabilities.
Mitigation selection guide
--------------------------
diff --git a/Documentation/admin-guide/hw-vuln/tsx_async_abort.rst b/Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
index fddbd7579c53..af6865b822d2 100644
--- a/Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
+++ b/Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
@@ -174,7 +174,10 @@ the option "tsx_async_abort=". The valid arguments for this option are:
CPU is not vulnerable to cross-thread TAA attacks.
============ =============================================================
-Not specifying this option is equivalent to "tsx_async_abort=full".
+Not specifying this option is equivalent to "tsx_async_abort=full". For
+processors that are affected by both TAA and MDS, specifying just
+"tsx_async_abort=off" without an accompanying "mds=off" will have no
+effect as the same mitigation is used for both vulnerabilities.
The kernel command line also allows to control the TSX feature using the
parameter "tsx=" on CPUs which support TSX control. MSR_IA32_TSX_CTRL is used
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 8dee8f68fe15..9983ac73b66d 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2473,6 +2473,12 @@
SMT on vulnerable CPUs
off - Unconditionally disable MDS mitigation
+ On TAA-affected machines, mds=off can be prevented by
+ an active TAA mitigation as both vulnerabilities are
+ mitigated with the same mechanism so in order to disable
+ this mitigation, you need to specify tsx_async_abort=off
+ too.
+
Not specifying this option is equivalent to
mds=full.
@@ -4931,6 +4937,11 @@
vulnerable to cross-thread TAA attacks.
off - Unconditionally disable TAA mitigation
+ On MDS-affected machines, tsx_async_abort=off can be
+ prevented by an active MDS mitigation as both vulnerabilities
+ are mitigated with the same mechanism so in order to disable
+ this mitigation, you need to specify mds=off too.
+
Not specifying this option is equivalent to
tsx_async_abort=full. On CPUs which are MDS affected
and deploy MDS mitigation, TAA mitigation is not