arch: make execmem setup available regardless of CONFIG_MODULES

execmem does not depend on modules, on the contrary modules use
execmem.

To make execmem available when CONFIG_MODULES=n, for instance for
kprobes, split execmem_params initialization out from
arch/*/kernel/module.c and compile it when CONFIG_EXECMEM=y

Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

1 files changed, 0 insertions, 140 deletions

diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c
index a52240ea084b..36b25af56324 100644
--- a/arch/arm64/kernel/module.c
+++ b/arch/arm64/kernel/module.c
@@ -12,158 +12,18 @@
 #include <linux/bitops.h>
 #include <linux/elf.h>
 #include <linux/ftrace.h>
-#include <linux/gfp.h>
 #include <linux/kasan.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/moduleloader.h>
 #include <linux/random.h>
 #include <linux/scs.h>
-#include <linux/vmalloc.h>
-#include <linux/execmem.h>
 
 #include <asm/alternative.h>
 #include <asm/insn.h>
 #include <asm/scs.h>
 #include <asm/sections.h>
 
-static u64 module_direct_base __ro_after_init = 0;
-static u64 module_plt_base __ro_after_init = 0;
-
-/*
- * Choose a random page-aligned base address for a window of 'size' bytes which
- * entirely contains the interval [start, end - 1].
- */
-static u64 __init random_bounding_box(u64 size, u64 start, u64 end)
-{
-	u64 max_pgoff, pgoff;
-
-	if ((end - start) >= size)
-		return 0;
-
-	max_pgoff = (size - (end - start)) / PAGE_SIZE;
-	pgoff = get_random_u32_inclusive(0, max_pgoff);
-
-	return start - pgoff * PAGE_SIZE;
-}
-
-/*
- * Modules may directly reference data and text anywhere within the kernel
- * image and other modules. References using PREL32 relocations have a +/-2G
- * range, and so we need to ensure that the entire kernel image and all modules
- * fall within a 2G window such that these are always within range.
- *
- * Modules may directly branch to functions and code within the kernel text,
- * and to functions and code within other modules. These branches will use
- * CALL26/JUMP26 relocations with a +/-128M range. Without PLTs, we must ensure
- * that the entire kernel text and all module text falls within a 128M window
- * such that these are always within range. With PLTs, we can expand this to a
- * 2G window.
- *
- * We chose the 128M region to surround the entire kernel image (rather than
- * just the text) as using the same bounds for the 128M and 2G regions ensures
- * by construction that we never select a 128M region that is not a subset of
- * the 2G region. For very large and unusual kernel configurations this means
- * we may fall back to PLTs where they could have been avoided, but this keeps
- * the logic significantly simpler.
- */
-static int __init module_init_limits(void)
-{
-	u64 kernel_end = (u64)_end;
-	u64 kernel_start = (u64)_text;
-	u64 kernel_size = kernel_end - kernel_start;
-
-	/*
-	 * The default modules region is placed immediately below the kernel
-	 * image, and is large enough to use the full 2G relocation range.
-	 */
-	BUILD_BUG_ON(KIMAGE_VADDR != MODULES_END);
-	BUILD_BUG_ON(MODULES_VSIZE < SZ_2G);
-
-	if (!kaslr_enabled()) {
-		if (kernel_size < SZ_128M)
-			module_direct_base = kernel_end - SZ_128M;
-		if (kernel_size < SZ_2G)
-			module_plt_base = kernel_end - SZ_2G;
-	} else {
-		u64 min = kernel_start;
-		u64 max = kernel_end;
-
-		if (IS_ENABLED(CONFIG_RANDOMIZE_MODULE_REGION_FULL)) {
-			pr_info("2G module region forced by RANDOMIZE_MODULE_REGION_FULL\n");
-		} else {
-			module_direct_base = random_bounding_box(SZ_128M, min, max);
-			if (module_direct_base) {
-				min = module_direct_base;
-				max = module_direct_base + SZ_128M;
-			}
-		}
-
-		module_plt_base = random_bounding_box(SZ_2G, min, max);
-	}
-
-	pr_info("%llu pages in range for non-PLT usage",
-		module_direct_base ? (SZ_128M - kernel_size) / PAGE_SIZE : 0);
-	pr_info("%llu pages in range for PLT usage",
-		module_plt_base ? (SZ_2G - kernel_size) / PAGE_SIZE : 0);
-
-	return 0;
-}
-
-static struct execmem_info execmem_info __ro_after_init;
-
-struct execmem_info __init *execmem_arch_setup(void)
-{
-	unsigned long fallback_start = 0, fallback_end = 0;
-	unsigned long start = 0, end = 0;
-
-	module_init_limits();
-
-	/*
-	 * Where possible, prefer to allocate within direct branch range of the
-	 * kernel such that no PLTs are necessary.
-	 */
-	if (module_direct_base) {
-		start = module_direct_base;
-		end = module_direct_base + SZ_128M;
-
-		if (module_plt_base) {
-			fallback_start = module_plt_base;
-			fallback_end = module_plt_base + SZ_2G;
-		}
-	} else if (module_plt_base) {
-		start = module_plt_base;
-		end = module_plt_base + SZ_2G;
-	}
-
-	execmem_info = (struct execmem_info){
-		.ranges = {
-			[EXECMEM_DEFAULT] = {
-				.start	= start,
-				.end	= end,
-				.pgprot	= PAGE_KERNEL,
-				.alignment = 1,
-				.fallback_start	= fallback_start,
-				.fallback_end	= fallback_end,
-			},
-			[EXECMEM_KPROBES] = {
-				.start	= VMALLOC_START,
-				.end	= VMALLOC_END,
-				.pgprot	= PAGE_KERNEL_ROX,
-				.alignment = 1,
-			},
-			[EXECMEM_BPF] = {
-				.start	= VMALLOC_START,
-				.end	= VMALLOC_END,
-				.pgprot	= PAGE_KERNEL,
-				.alignment = 1,
-			},
-		},
-	};
-
-	return &execmem_info;
-}
-
 enum aarch64_reloc_op {
 	RELOC_OP_NONE,
 	RELOC_OP_ABS,