+ x86-execmem-fix-rox-cache-usage-in-xen-pv-guests.patch added to mm-hotfixes-unstable branch

+ x86-execmem-fix-rox-cache-usage-in-xen-pv-guests.patch added to mm-hotfixes-unstable branch

[Andrew Morton]

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The patch titled
     Subject: x86/execmem: fix ROX cache usage in Xen PV guests
has been added to the -mm mm-hotfixes-unstable branch.  Its filename is
     x86-execmem-fix-rox-cache-usage-in-xen-pv-guests.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/x86-execmem-fix-rox-cache-usage-in-xen-pv-guests.patch

This patch will later appear in the mm-hotfixes-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Juergen Gross <jgross@suse.com>
Subject: x86/execmem: fix ROX cache usage in Xen PV guests
Date: Fri, 3 Jan 2025 07:56:31 +0100

The recently introduced ROX cache for modules is assuming large page
support in 64-bit mode without testing the related feature bit.  This
results in breakage when running as a Xen PV guest, as in this mode large
pages are not supported.

Fix that by testing the X86_FEATURE_PSE capability when deciding whether
to enable the ROX cache.

Link: https://lkml.kernel.org/r/20250103065631.26459-1-jgross@suse.com
Fixes: 2e45474ab14f ("execmem: add support for cache of large ROX pages")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/x86/mm/init.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/arch/x86/mm/init.c~x86-execmem-fix-rox-cache-usage-in-xen-pv-guests
+++ a/arch/x86/mm/init.c
@@ -1080,7 +1080,8 @@ struct execmem_info __init *execmem_arch
 
 	start = MODULES_VADDR + offset;
 
-	if (IS_ENABLED(CONFIG_ARCH_HAS_EXECMEM_ROX)) {
+	if (IS_ENABLED(CONFIG_ARCH_HAS_EXECMEM_ROX) &&
+	    cpu_feature_enabled(X86_FEATURE_PSE)) {
 		pgprot = PAGE_KERNEL_ROX;
 		flags = EXECMEM_KASAN_SHADOW | EXECMEM_ROX_CACHE;
 	} else {
_

Patches currently in -mm which might be from jgross@suse.com are

x86-execmem-fix-rox-cache-usage-in-xen-pv-guests.patch