Update to 5.18.6.p2-1

- New upstream release based on 5.18.5
- Add MGLRU Zen patch
- Add linux-5.18.6 patches
- Move System.map from -headers into the base package to avoid
  external modules having wrong bpf symbols when running optimized
  builds. Fixes #5
- Remove M/m from CPUSUFFIXES_KBUILD and LCPU, fixes build failing
  when selecting an optimized build architecture that is not genering.
  Fixes #6.

Signed-off-by: Björn Bidar <bjorn.bidar@thaodan.de>

1 files changed, 76 insertions, 0 deletions

diff --git a/0124-cfi-Fix-__cfi_slowpath_diag-RCU-usage-with-cpuidle.patch b/0124-cfi-Fix-__cfi_slowpath_diag-RCU-usage-with-cpuidle.patch
new file mode 100644
index 000000000000..e1e9c7eb0481
--- /dev/null
+++ b/0124-cfi-Fix-__cfi_slowpath_diag-RCU-usage-with-cpuidle.patch
@@ -0,0 +1,76 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Sami Tolvanen <samitolvanen@google.com>
+Date: Tue, 31 May 2022 10:59:10 -0700
+Subject: [PATCH] cfi: Fix __cfi_slowpath_diag RCU usage with cpuidle
+
+commit 57cd6d157eb479f0a8e820fd36b7240845c8a937 upstream.
+
+RCU_NONIDLE usage during __cfi_slowpath_diag can result in an invalid
+RCU state in the cpuidle code path:
+
+  WARNING: CPU: 1 PID: 0 at kernel/rcu/tree.c:613 rcu_eqs_enter+0xe4/0x138
+  ...
+  Call trace:
+    rcu_eqs_enter+0xe4/0x138
+    rcu_idle_enter+0xa8/0x100
+    cpuidle_enter_state+0x154/0x3a8
+    cpuidle_enter+0x3c/0x58
+    do_idle.llvm.6590768638138871020+0x1f4/0x2ec
+    cpu_startup_entry+0x28/0x2c
+    secondary_start_kernel+0x1b8/0x220
+    __secondary_switched+0x94/0x98
+
+Instead, call rcu_irq_enter/exit to wake up RCU only when needed and
+disable interrupts for the entire CFI shadow/module check when we do.
+
+Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
+Link: https://lore.kernel.org/r/20220531175910.890307-1-samitolvanen@google.com
+Fixes: cf68fffb66d6 ("add support for Clang CFI")
+Cc: stable@vger.kernel.org
+Signed-off-by: Kees Cook <keescook@chromium.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ kernel/cfi.c | 22 ++++++++++++++++------
+ 1 file changed, 16 insertions(+), 6 deletions(-)
+
+diff --git a/kernel/cfi.c b/kernel/cfi.c
+index 9594cfd1cf2cf7ea7be1a44ad048d3b25b624acc..08102d19ec15a2e402c10ad8d22743caafe47d68 100644
+--- a/kernel/cfi.c
++++ b/kernel/cfi.c
+@@ -281,6 +281,8 @@ static inline cfi_check_fn find_module_check_fn(unsigned long ptr)
+ static inline cfi_check_fn find_check_fn(unsigned long ptr)
+ {
+ 	cfi_check_fn fn = NULL;
++	unsigned long flags;
++	bool rcu_idle;
+ 
+ 	if (is_kernel_text(ptr))
+ 		return __cfi_check;
+@@ -290,13 +292,21 @@ static inline cfi_check_fn find_check_fn(unsigned long ptr)
+ 	 * the shadow and __module_address use RCU, so we need to wake it
+ 	 * up if necessary.
+ 	 */
+-	RCU_NONIDLE({
+-		if (IS_ENABLED(CONFIG_CFI_CLANG_SHADOW))
+-			fn = find_shadow_check_fn(ptr);
++	rcu_idle = !rcu_is_watching();
++	if (rcu_idle) {
++		local_irq_save(flags);
++		rcu_irq_enter();
++	}
++
++	if (IS_ENABLED(CONFIG_CFI_CLANG_SHADOW))
++		fn = find_shadow_check_fn(ptr);
++	if (!fn)
++		fn = find_module_check_fn(ptr);
+ 
+-		if (!fn)
+-			fn = find_module_check_fn(ptr);
+-	});
++	if (rcu_idle) {
++		rcu_irq_exit();
++		local_irq_restore(flags);
++	}
+ 
+ 	return fn;
+ }