x86/module: enable ROX caches for module text on 64 bit

jira LE-4694
Rebuild_History Non-Buildable kernel-6.12.0-55.43.1.el10_0
commit-author Mike Rapoport (Microsoft) <rppt@kernel.org>
commit 5185e7f

Enable execmem's cache of PMD_SIZE'ed pages mapped as ROX for module text
allocations on 64 bit.

Link: https://lkml.kernel.org/r/20241023162711.2579610-9-rppt@kernel.org
	Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
	Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
	Tested-by: kdevops <kdevops@lists.linux.dev>
	Cc: Andreas Larsson <andreas@gaisler.com>
	Cc: Andy Lutomirski <luto@kernel.org>
	Cc: Ard Biesheuvel <ardb@kernel.org>
	Cc: Arnd Bergmann <arnd@arndb.de>
	Cc: Borislav Petkov (AMD) <bp@alien8.de>
	Cc: Brian Cain <bcain@quicinc.com>
	Cc: Catalin Marinas <catalin.marinas@arm.com>
	Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
	Cc: Christoph Hellwig <hch@lst.de>
	Cc: Dave Hansen <dave.hansen@linux.intel.com>
	Cc: Dinh Nguyen <dinguyen@kernel.org>
	Cc: Geert Uytterhoeven <geert@linux-m68k.org>
	Cc: Guo Ren <guoren@kernel.org>
	Cc: Helge Deller <deller@gmx.de>
	Cc: Huacai Chen <chenhuacai@kernel.org>
	Cc: Ingo Molnar <mingo@redhat.com>
	Cc: Johannes Berg <johannes@sipsolutions.net>
	Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
	Cc: Kent Overstreet <kent.overstreet@linux.dev>
	Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
	Cc: Mark Rutland <mark.rutland@arm.com>
	Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
	Cc: Matt Turner <mattst88@gmail.com>
	Cc: Max Filippov <jcmvbkbc@gmail.com>
	Cc: Michael Ellerman <mpe@ellerman.id.au>
	Cc: Michal Simek <monstr@monstr.eu>
	Cc: Oleg Nesterov <oleg@redhat.com>
	Cc: Palmer Dabbelt <palmer@dabbelt.com>
	Cc: Peter Zijlstra <peterz@infradead.org>
	Cc: Richard Weinberger <richard@nod.at>
	Cc: Russell King <linux@armlinux.org.uk>
	Cc: Song Liu <song@kernel.org>
	Cc: Stafford Horne <shorne@gmail.com>
	Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
	Cc: Suren Baghdasaryan <surenb@google.com>
	Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
	Cc: Thomas Gleixner <tglx@linutronix.de>
	Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
	Cc: Vineet Gupta <vgupta@kernel.org>
	Cc: Will Deacon <will@kernel.org>
	Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
(cherry picked from commit 5185e7f)
	Signed-off-by: Jonathan Maple <jmaple@ciq.com>

Author: PlaidCat

arch/x86/Kconfig

@@ -83,6 +83,7 @@ config X86
 	select ARCH_HAS_DMA_OPS			if GART_IOMMU || XEN
 	select ARCH_HAS_EARLY_DEBUG		if KGDB
 	select ARCH_HAS_ELF_RANDOMIZE
+	select ARCH_HAS_EXECMEM_ROX		if X86_64
 	select ARCH_HAS_FAST_MULTIPLIER
 	select ARCH_HAS_FORTIFY_SOURCE
 	select ARCH_HAS_GCOV_PROFILE_ALL

arch/x86/mm/init.c

@@ -1053,18 +1053,53 @@ unsigned long arch_max_swapfile_size(void)
 #ifdef CONFIG_EXECMEM
 static struct execmem_info execmem_info __ro_after_init;
 
+#ifdef CONFIG_ARCH_HAS_EXECMEM_ROX
+void execmem_fill_trapping_insns(void *ptr, size_t size, bool writeable)
+{
+	/* fill memory with INT3 instructions */
+	if (writeable)
+		memset(ptr, INT3_INSN_OPCODE, size);
+	else
+		text_poke_set(ptr, INT3_INSN_OPCODE, size);
+}
+#endif
+
 struct execmem_info __init *execmem_arch_setup(void)
 {
 	unsigned long start, offset = 0;
+	enum execmem_range_flags flags;
+	pgprot_t pgprot;
 
 	if (kaslr_enabled())
 		offset = get_random_u32_inclusive(1, 1024) * PAGE_SIZE;
 
 	start = MODULES_VADDR + offset;
 
+	if (IS_ENABLED(CONFIG_ARCH_HAS_EXECMEM_ROX)) {
+		pgprot = PAGE_KERNEL_ROX;
+		flags = EXECMEM_KASAN_SHADOW | EXECMEM_ROX_CACHE;
+	} else {
+		pgprot = PAGE_KERNEL;
+		flags = EXECMEM_KASAN_SHADOW;
+	}
+
 	execmem_info = (struct execmem_info){
 		.ranges = {
-			[EXECMEM_DEFAULT] = {
+			[EXECMEM_MODULE_TEXT] = {
+				.flags	= flags,
+				.start	= start,
+				.end	= MODULES_END,
+				.pgprot	= pgprot,
+				.alignment = MODULE_ALIGN,
+			},
+			[EXECMEM_KPROBES ... EXECMEM_BPF] = {
+				.flags	= EXECMEM_KASAN_SHADOW,
+				.start	= start,
+				.end	= MODULES_END,
+				.pgprot	= PAGE_KERNEL,
+				.alignment = MODULE_ALIGN,
+			},
+			[EXECMEM_MODULE_DATA] = {
 				.flags	= EXECMEM_KASAN_SHADOW,
 				.start	= start,
 				.end	= MODULES_END,