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authorChang S. Bae <chang.seok.bae@intel.com>2021-10-21 15:55:27 -0700
committerBorislav Petkov <bp@suse.de>2021-10-26 10:53:03 +0200
commit2308ee57d93d896618dd65c996429c9d3e469fe0 (patch)
treebaa443ee20a3f77e78fced1523307383b21b78b6 /arch/x86/kernel/fpu/core.c
parentdb3e7321b4b84b1cb39598ff79b90d1252481378 (diff)
x86/fpu/amx: Enable the AMX feature in 64-bit mode
Add the AMX state components in XFEATURE_MASK_USER_SUPPORTED and the TILE_DATA component to the dynamic states and update the permission check table accordingly. This is only effective on 64 bit kernels as for 32bit kernels XFEATURE_MASK_TILE is defined as 0. TILE_DATA is caller-saved state and the only dynamic state. Add build time sanity check to ensure the assumption that every dynamic feature is caller- saved. Make AMX state depend on XFD as it is dynamic feature. Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20211021225527.10184-24-chang.seok.bae@intel.com
Diffstat (limited to 'arch/x86/kernel/fpu/core.c')
-rw-r--r--arch/x86/kernel/fpu/core.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index 12ca174891dc..290836d1f2a7 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -495,6 +495,12 @@ int fpu_clone(struct task_struct *dst, unsigned long clone_flags)
}
/*
+ * If a new feature is added, ensure all dynamic features are
+ * caller-saved from here!
+ */
+ BUILD_BUG_ON(XFEATURE_MASK_USER_DYNAMIC != XFEATURE_MASK_XTILE_DATA);
+
+ /*
* Save the default portion of the current FPU state into the
* clone. Assume all dynamic features to be defined as caller-
* saved, which enables skipping both the expansion of fpstate