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authorLinus Torvalds <torvalds@linux-foundation.org>2021-11-14 09:29:03 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2021-11-14 09:29:03 -0800
commit1654e95ee30a82bec843e73a591f9ea3db8da8db (patch)
tree7bd8d2c6d1d0f0dc176abcf02fccdfbb0c8e4fc8 /Documentation
parent35c8fad4a703fdfa009ed274f80bb64b49314cde (diff)
parentfbdb5e8f2926ae9636c9fa6f42c7426132ddeeb2 (diff)
downloadlinux-1654e95ee30a82bec843e73a591f9ea3db8da8db.tar.bz2
Merge tag 'x86_urgent_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov: - Add the model number of a new, Raptor Lake CPU, to intel-family.h - Do not log spurious corrected MCEs on SKL too, due to an erratum - Clarify the path of paravirt ops patches upstream - Add an optimization to avoid writing out AMX components to sigframes when former are in init state * tag 'x86_urgent_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu: Add Raptor Lake to Intel family x86/mce: Add errata workaround for Skylake SKX37 MAINTAINERS: Add some information to PARAVIRT_OPS entry x86/fpu: Optimize out sigframe xfeatures when in init state
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/x86/xstate.rst9
1 files changed, 9 insertions, 0 deletions
diff --git a/Documentation/x86/xstate.rst b/Documentation/x86/xstate.rst
index 65de3f054ba5..5cec7fb558d6 100644
--- a/Documentation/x86/xstate.rst
+++ b/Documentation/x86/xstate.rst
@@ -63,3 +63,12 @@ kernel sends SIGILL to the application. If the process has permission then
the handler allocates a larger xstate buffer for the task so the large
state can be context switched. In the unlikely cases that the allocation
fails, the kernel sends SIGSEGV.
+
+Dynamic features in signal frames
+---------------------------------
+
+Dynamcally enabled features are not written to the signal frame upon signal
+entry if the feature is in its initial configuration. This differs from
+non-dynamic features which are always written regardless of their
+configuration. Signal handlers can examine the XSAVE buffer's XSTATE_BV
+field to determine if a features was written.