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@xxxxxxxx>
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@xxxxxxxx
Fixes: 2e45474ab14f ("execmem: add support for cache of large ROX pages")
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Reported-by: Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>
Tested-by: Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
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@xxxxxxxx are
x86-execmem-fix-rox-cache-usage-in-xen-pv-guests.patch
