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authorLinus Torvalds <torvalds@linux-foundation.org>2024-05-15 14:05:08 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2024-05-15 14:05:08 -0700
commita49468240e89628236b738b5ab9416eae8f90c15 (patch)
treeaed63fd4ccb7bff9df171e469429e0c7eec5cc46 /arch/arm64/kernel
parent8c06da67d0bd3139a97f301b4aa9c482b9d4f29e (diff)
parent2c9e5d4a008293407836d29d35dfd4353615bd2f (diff)
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Merge tag 'modules-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux
Pull modules updates from Luis Chamberlain: "Finally something fun. Mike Rapoport does some cleanup to allow us to take out module_alloc() out of modules into a new paint shedded execmem_alloc() and execmem_free() so to make emphasis these helpers are actually used outside of modules. It starts with a non-functional changes API rename / placeholders to then allow architectures to define their requirements into a new shiny struct execmem_info with ranges, and requirements for those ranges. Archs now can intitialize this execmem_info as the last part of mm_core_init() if they have to diverge from the norm. Each range is a known type clearly articulated and spelled out in enum execmem_type. Although a lot of this is major cleanup and prep work for future enhancements an immediate clear gain is we get to enable KPROBES without MODULES now. That is ultimately what motiviated to pick this work up again, now with smaller goal as concrete stepping stone" * tag 'modules-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: bpf: remove CONFIG_BPF_JIT dependency on CONFIG_MODULES of kprobes: remove dependency on CONFIG_MODULES powerpc: use CONFIG_EXECMEM instead of CONFIG_MODULES where appropriate x86/ftrace: enable dynamic ftrace without CONFIG_MODULES arch: make execmem setup available regardless of CONFIG_MODULES powerpc: extend execmem_params for kprobes allocations arm64: extend execmem_info for generated code allocations riscv: extend execmem_params for generated code allocations mm/execmem, arch: convert remaining overrides of module_alloc to execmem mm/execmem, arch: convert simple overrides of module_alloc to execmem mm: introduce execmem_alloc() and execmem_free() module: make module_memory_{alloc,free} more self-contained sparc: simplify module_alloc() nios2: define virtual address space for modules mips: module: rename MODULE_START to MODULES_VADDR arm64: module: remove unneeded call to kasan_alloc_module_shadow() kallsyms: replace deprecated strncpy with strscpy module: allow UNUSED_KSYMS_WHITELIST to be relative against objtree.
Diffstat (limited to 'arch/arm64/kernel')
-rw-r--r--arch/arm64/kernel/module.c126
-rw-r--r--arch/arm64/kernel/probes/kprobes.c7
2 files changed, 0 insertions, 133 deletions
diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c
index 47e0be610bb6..36b25af56324 100644
--- a/arch/arm64/kernel/module.c
+++ b/arch/arm64/kernel/module.c
@@ -12,144 +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 <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;
-}
-subsys_initcall(module_init_limits);
-
-void *module_alloc(unsigned long size)
-{
- void *p = NULL;
-
- /*
- * Where possible, prefer to allocate within direct branch range of the
- * kernel such that no PLTs are necessary.
- */
- if (module_direct_base) {
- p = __vmalloc_node_range(size, MODULE_ALIGN,
- module_direct_base,
- module_direct_base + SZ_128M,
- GFP_KERNEL | __GFP_NOWARN,
- PAGE_KERNEL, 0, NUMA_NO_NODE,
- __builtin_return_address(0));
- }
-
- if (!p && module_plt_base) {
- p = __vmalloc_node_range(size, MODULE_ALIGN,
- module_plt_base,
- module_plt_base + SZ_2G,
- GFP_KERNEL | __GFP_NOWARN,
- PAGE_KERNEL, 0, NUMA_NO_NODE,
- __builtin_return_address(0));
- }
-
- if (!p) {
- pr_warn_ratelimited("%s: unable to allocate memory\n",
- __func__);
- }
-
- if (p && (kasan_alloc_module_shadow(p, size, GFP_KERNEL) < 0)) {
- vfree(p);
- return NULL;
- }
-
- /* Memory is intended to be executable, reset the pointer tag. */
- return kasan_reset_tag(p);
-}
-
enum aarch64_reloc_op {
RELOC_OP_NONE,
RELOC_OP_ABS,
diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c
index 327855a11df2..4268678d0e86 100644
--- a/arch/arm64/kernel/probes/kprobes.c
+++ b/arch/arm64/kernel/probes/kprobes.c
@@ -129,13 +129,6 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
return 0;
}
-void *alloc_insn_page(void)
-{
- return __vmalloc_node_range(PAGE_SIZE, 1, VMALLOC_START, VMALLOC_END,
- GFP_KERNEL, PAGE_KERNEL_ROX, VM_FLUSH_RESET_PERMS,
- NUMA_NO_NODE, __builtin_return_address(0));
-}
-
/* arm kprobe: install breakpoint in text */
void __kprobes arch_arm_kprobe(struct kprobe *p)
{