4.19-stable patches

added patches:
	x86-cpu-initialize-msr_tsc_aux-if-rdtscp-or-rdpid-is-supported.patch

diff --git a/queue-4.19/series b/queue-4.19/series
index ddb7f709d5f001d70b0af529257ea8cf0df078aa..b2673da771a2dd1cafb773e374bb69bb009e1ed3 100644 (file)
--- a/queue-4.19/series
+++ b/queue-4.19/series
@@ -155,3 +155,4 @@ alsa-hda-realtek-re-order-alc269-dell-quirk-table-entries.patch
 alsa-hda-realtek-re-order-alc269-sony-quirk-table-entries.patch
 alsa-hda-realtek-re-order-alc269-lenovo-quirk-table-entries.patch
 alsa-hda-realtek-remove-redundant-entry-for-alc861-haier-uniwill-devices.patch
+x86-cpu-initialize-msr_tsc_aux-if-rdtscp-or-rdpid-is-supported.patch

diff --git a/queue-4.19/x86-cpu-initialize-msr_tsc_aux-if-rdtscp-or-rdpid-is-supported.patch b/queue-4.19/x86-cpu-initialize-msr_tsc_aux-if-rdtscp-or-rdpid-is-supported.patch
new file mode 100644 (file)
index 0000000..988a81e
--- /dev/null
+++ b/queue-4.19/x86-cpu-initialize-msr_tsc_aux-if-rdtscp-or-rdpid-is-supported.patch
@@ -0,0 +1,43 @@
+From b6b4fbd90b155a0025223df2c137af8a701d53b3 Mon Sep 17 00:00:00 2001
+From: Sean Christopherson <seanjc@google.com>
+Date: Tue, 4 May 2021 15:56:31 -0700
+Subject: x86/cpu: Initialize MSR_TSC_AUX if RDTSCP *or* RDPID is supported
+
+From: Sean Christopherson <seanjc@google.com>
+
+commit b6b4fbd90b155a0025223df2c137af8a701d53b3 upstream.
+
+Initialize MSR_TSC_AUX with CPU node information if RDTSCP or RDPID is
+supported.  This fixes a bug where vdso_read_cpunode() will read garbage
+via RDPID if RDPID is supported but RDTSCP is not.  While no known CPU
+supports RDPID but not RDTSCP, both Intel's SDM and AMD's APM allow for
+RDPID to exist without RDTSCP, e.g. it's technically a legal CPU model
+for a virtual machine.
+
+Note, technically MSR_TSC_AUX could be initialized if and only if RDPID
+is supported since RDTSCP is currently not used to retrieve the CPU node.
+But, the cost of the superfluous WRMSR is negigible, whereas leaving
+MSR_TSC_AUX uninitialized is just asking for future breakage if someone
+decides to utilize RDTSCP.
+
+Fixes: a582c540ac1b ("x86/vdso: Use RDPID in preference to LSL when available")
+Signed-off-by: Sean Christopherson <seanjc@google.com>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Cc: stable@vger.kernel.org
+Link: https://lore.kernel.org/r/20210504225632.1532621-2-seanjc@google.com
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/x86/entry/vdso/vma.c |    2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/arch/x86/entry/vdso/vma.c
++++ b/arch/x86/entry/vdso/vma.c
+@@ -343,7 +343,7 @@ static void vgetcpu_cpu_init(void *arg)
+ #ifdef CONFIG_NUMA
+       node = cpu_to_node(cpu);
+ #endif
+-      if (static_cpu_has(X86_FEATURE_RDTSCP))
++      if (boot_cpu_has(X86_FEATURE_RDTSCP) || boot_cpu_has(X86_FEATURE_RDPID))
+               write_rdtscp_aux((node << 12) | cpu);
+ 
+       /*