Merge tag 'x86_urgent_for_v5.16_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Borislav Petkov:

 - Fix a couple of SWAPGS fencing issues in the x86 entry code

 - Use the proper operand types in __{get,put}_user() to prevent
   truncation in SEV-ES string io

 - Make sure the kernel mappings are present in trampoline_pgd in order
   to prevent any potential accesses to unmapped memory after switching
   to it

 - Fix a trivial list corruption in objtool's pv_ops validation

 - Disable the clocksource watchdog for TSC on platforms which claim
   that the TSC is constant, doesn't stop in sleep states, CPU has TSC
   adjust and the number of sockets of the platform are max 2, to
   prevent erroneous markings of the TSC as unstable.

 - Make sure TSC adjust is always checked not only when going idle

 - Prevent a stack leak by initializing struct _fpx_sw_bytes properly in
   the FPU code

 - Fix INTEL_FAM6_RAPTORLAKE define naming to adhere to the convention

* tag 'x86_urgent_for_v5.16_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/xen: Add xenpv_restore_regs_and_return_to_usermode()
  x86/entry: Use the correct fence macro after swapgs in kernel CR3
  x86/entry: Add a fence for kernel entry SWAPGS in paranoid_entry()
  x86/sev: Fix SEV-ES INS/OUTS instructions for word, dword, and qword
  x86/64/mm: Map all kernel memory into trampoline_pgd
  objtool: Fix pv_ops noinstr validation
  x86/tsc: Disable clocksource watchdog for TSC on qualified platorms
  x86/tsc: Add a timer to make sure TSC_adjust is always checked
  x86/fpu/signal: Initialize sw_bytes in save_xstate_epilog()
  x86/cpu: Drop spurious underscore from RAPTOR_LAKE #define

1 files changed, 24 insertions, 4 deletions

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 2e076a459a0c..a698196377be 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -1180,6 +1180,12 @@ void mark_tsc_unstable(char *reason)
 
 EXPORT_SYMBOL_GPL(mark_tsc_unstable);
 
+static void __init tsc_disable_clocksource_watchdog(void)
+{
+	clocksource_tsc_early.flags &= ~CLOCK_SOURCE_MUST_VERIFY;
+	clocksource_tsc.flags &= ~CLOCK_SOURCE_MUST_VERIFY;
+}
+
 static void __init check_system_tsc_reliable(void)
 {
 #if defined(CONFIG_MGEODEGX1) || defined(CONFIG_MGEODE_LX) || defined(CONFIG_X86_GENERIC)
@@ -1196,6 +1202,23 @@ static void __init check_system_tsc_reliable(void)
 #endif
 	if (boot_cpu_has(X86_FEATURE_TSC_RELIABLE))
 		tsc_clocksource_reliable = 1;
+
+	/*
+	 * Disable the clocksource watchdog when the system has:
+	 *  - TSC running at constant frequency
+	 *  - TSC which does not stop in C-States
+	 *  - the TSC_ADJUST register which allows to detect even minimal
+	 *    modifications
+	 *  - not more than two sockets. As the number of sockets cannot be
+	 *    evaluated at the early boot stage where this has to be
+	 *    invoked, check the number of online memory nodes as a
+	 *    fallback solution which is an reasonable estimate.
+	 */
+	if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC) &&
+	    boot_cpu_has(X86_FEATURE_NONSTOP_TSC) &&
+	    boot_cpu_has(X86_FEATURE_TSC_ADJUST) &&
+	    nr_online_nodes <= 2)
+		tsc_disable_clocksource_watchdog();
 }
 
 /*
@@ -1387,9 +1410,6 @@ static int __init init_tsc_clocksource(void)
 	if (tsc_unstable)
 		goto unreg;
 
-	if (tsc_clocksource_reliable || no_tsc_watchdog)
-		clocksource_tsc.flags &= ~CLOCK_SOURCE_MUST_VERIFY;
-
 	if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC_S3))
 		clocksource_tsc.flags |= CLOCK_SOURCE_SUSPEND_NONSTOP;
 
@@ -1527,7 +1547,7 @@ void __init tsc_init(void)
 	}
 
 	if (tsc_clocksource_reliable || no_tsc_watchdog)
-		clocksource_tsc_early.flags &= ~CLOCK_SOURCE_MUST_VERIFY;
+		tsc_disable_clocksource_watchdog();
 
 	clocksource_register_khz(&clocksource_tsc_early, tsc_khz);
 	detect_art();