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authorLinus Torvalds <torvalds@linux-foundation.org>2021-06-06 12:25:43 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-06-06 12:25:43 -0700
commit773ac53bbfcebb58ce03577d94ce471cadf3ea18 (patch)
tree85589df85dd576b73960eac2b9b6671b619f1e43 /arch/x86/kernel/fpu/xstate.c
parentf5b6eb1e018203913dfefcf6fa988649ad11ad6e (diff)
parent009767dbf42ac0dbe3cf48c1ee224f6b778aa85a (diff)
Merge tag 'x86_urgent_for_v5.13-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov: "A bunch of x86/urgent stuff accumulated for the last two weeks so lemme unload it to you. It should be all totally risk-free, of course. :-) - Fix out-of-spec hardware (1st gen Hygon) which does not implement MSR_AMD64_SEV even though the spec clearly states so, and check CPUID bits first. - Send only one signal to a task when it is a SEGV_PKUERR si_code type. - Do away with all the wankery of reserving X amount of memory in the first megabyte to prevent BIOS corrupting it and simply and unconditionally reserve the whole first megabyte. - Make alternatives NOP optimization work at an arbitrary position within the patched sequence because the compiler can put single-byte NOPs for alignment anywhere in the sequence (32-bit retpoline), vs our previous assumption that the NOPs are only appended. - Force-disable ENQCMD[S] instructions support and remove update_pasid() because of insufficient protection against FPU state modification in an interrupt context, among other xstate horrors which are being addressed at the moment. This one limits the fallout until proper enablement. - Use cpu_feature_enabled() in the idxd driver so that it can be build-time disabled through the defines in disabled-features.h. - Fix LVT thermal setup for SMI delivery mode by making sure the APIC LVT value is read before APIC initialization so that softlockups during boot do not happen at least on one machine. - Mark all legacy interrupts as legacy vectors when the IO-APIC is disabled and when all legacy interrupts are routed through the PIC" * tag 'x86_urgent_for_v5.13-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/sev: Check SME/SEV support in CPUID first x86/fault: Don't send SIGSEGV twice on SEGV_PKUERR x86/setup: Always reserve the first 1M of RAM x86/alternative: Optimize single-byte NOPs at an arbitrary position x86/cpufeatures: Force disable X86_FEATURE_ENQCMD and remove update_pasid() dmaengine: idxd: Use cpu_feature_enabled() x86/thermal: Fix LVT thermal setup for SMI delivery mode x86/apic: Mark _all_ legacy interrupts when IO/APIC is missing
Diffstat (limited to 'arch/x86/kernel/fpu/xstate.c')
-rw-r--r--arch/x86/kernel/fpu/xstate.c57
1 files changed, 0 insertions, 57 deletions
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index a85c64000218..d0eef963aad1 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -1402,60 +1402,3 @@ int proc_pid_arch_status(struct seq_file *m, struct pid_namespace *ns,
return 0;
}
#endif /* CONFIG_PROC_PID_ARCH_STATUS */
-
-#ifdef CONFIG_IOMMU_SUPPORT
-void update_pasid(void)
-{
- u64 pasid_state;
- u32 pasid;
-
- if (!cpu_feature_enabled(X86_FEATURE_ENQCMD))
- return;
-
- if (!current->mm)
- return;
-
- pasid = READ_ONCE(current->mm->pasid);
- /* Set the valid bit in the PASID MSR/state only for valid pasid. */
- pasid_state = pasid == PASID_DISABLED ?
- pasid : pasid | MSR_IA32_PASID_VALID;
-
- /*
- * No need to hold fregs_lock() since the task's fpstate won't
- * be changed by others (e.g. ptrace) while the task is being
- * switched to or is in IPI.
- */
- if (!test_thread_flag(TIF_NEED_FPU_LOAD)) {
- /* The MSR is active and can be directly updated. */
- wrmsrl(MSR_IA32_PASID, pasid_state);
- } else {
- struct fpu *fpu = &current->thread.fpu;
- struct ia32_pasid_state *ppasid_state;
- struct xregs_state *xsave;
-
- /*
- * The CPU's xstate registers are not currently active. Just
- * update the PASID state in the memory buffer here. The
- * PASID MSR will be loaded when returning to user mode.
- */
- xsave = &fpu->state.xsave;
- xsave->header.xfeatures |= XFEATURE_MASK_PASID;
- ppasid_state = get_xsave_addr(xsave, XFEATURE_PASID);
- /*
- * Since XFEATURE_MASK_PASID is set in xfeatures, ppasid_state
- * won't be NULL and no need to check its value.
- *
- * Only update the task's PASID state when it's different
- * from the mm's pasid.
- */
- if (ppasid_state->pasid != pasid_state) {
- /*
- * Invalid fpregs so that state restoring will pick up
- * the PASID state.
- */
- __fpu_invalidate_fpregs_state(fpu);
- ppasid_state->pasid = pasid_state;
- }
- }
-}
-#endif /* CONFIG_IOMMU_SUPPORT */