@@ -960,6 +960,14 @@ config ARCH_WANTS_MODULES_DATA_IN_VMALLOC
For architectures like powerpc/32 which have constraints on module
allocation and need to allocate module data outside of module area.
+config ARCH_WANTS_EXECMEM_LATE
+ bool
+ help
+ For architectures that do not allocate executable memory early on
+ boot, but rather require its initialization late when there is
+ enough entropy for module space randomization, for instance
+ arm64.
+
config HAVE_IRQ_EXIT_ON_IRQ_STACK
bool
help
@@ -16,6 +16,7 @@
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/gfp.h>
+#include <linux/execmem.h>
#include <asm/sections.h>
#include <asm/smp_plat.h>
@@ -34,23 +35,31 @@
#endif
#ifdef CONFIG_MMU
-void *module_alloc(unsigned long size)
+static struct execmem_info execmem_info __ro_after_init;
+
+struct execmem_info __init *execmem_arch_setup(void)
{
- gfp_t gfp_mask = GFP_KERNEL;
- void *p;
-
- /* Silence the initial allocation */
- if (IS_ENABLED(CONFIG_ARM_MODULE_PLTS))
- gfp_mask |= __GFP_NOWARN;
-
- p = __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
- gfp_mask, PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
- __builtin_return_address(0));
- if (!IS_ENABLED(CONFIG_ARM_MODULE_PLTS) || p)
- return p;
- return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
- GFP_KERNEL, PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
- __builtin_return_address(0));
+ unsigned long fallback_start = 0, fallback_end = 0;
+
+ if (IS_ENABLED(CONFIG_ARM_MODULE_PLTS)) {
+ fallback_start = VMALLOC_START;
+ fallback_end = VMALLOC_END;
+ }
+
+ execmem_info = (struct execmem_info){
+ .ranges = {
+ [EXECMEM_DEFAULT] = {
+ .start = MODULES_VADDR,
+ .end = MODULES_END,
+ .pgprot = PAGE_KERNEL_EXEC,
+ .alignment = 1,
+ .fallback_start = fallback_start,
+ .fallback_end = fallback_end,
+ },
+ },
+ };
+
+ return &execmem_info;
}
#endif
@@ -105,6 +105,7 @@ config ARM64
select ARCH_WANT_FRAME_POINTERS
select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
select ARCH_WANT_LD_ORPHAN_WARN
+ select ARCH_WANTS_EXECMEM_LATE if EXECMEM
select ARCH_WANTS_NO_INSTR
select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES
select ARCH_HAS_UBSAN
@@ -20,6 +20,7 @@
#include <linux/random.h>
#include <linux/scs.h>
#include <linux/vmalloc.h>
+#include <linux/execmem.h>
#include <asm/alternative.h>
#include <asm/insn.h>
@@ -108,41 +109,47 @@ static int __init module_init_limits(void)
return 0;
}
-subsys_initcall(module_init_limits);
-void *module_alloc(unsigned long size)
+static struct execmem_info execmem_info __ro_after_init;
+
+struct execmem_info __init *execmem_arch_setup(void)
{
- void *p = NULL;
+ 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) {
- 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));
- }
+ start = module_direct_base;
+ end = module_direct_base + SZ_128M;
- 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 (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;
}
- /* Memory is intended to be executable, reset the pointer tag. */
- return kasan_reset_tag(p);
+ 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,
+ },
+ },
+ };
+
+ return &execmem_info;
}
enum aarch64_reloc_op {
@@ -10,6 +10,7 @@
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include <linux/bug.h>
+#include <linux/execmem.h>
#include <asm/module.h>
#include <linux/uaccess.h>
#include <asm/firmware.h>
@@ -89,39 +90,56 @@ int module_finalize(const Elf_Ehdr *hdr,
return 0;
}
-static __always_inline void *
-__module_alloc(unsigned long size, unsigned long start, unsigned long end, bool nowarn)
+static struct execmem_info execmem_info __ro_after_init;
+
+struct execmem_info __init *execmem_arch_setup(void)
{
pgprot_t prot = strict_module_rwx_enabled() ? PAGE_KERNEL : PAGE_KERNEL_EXEC;
- gfp_t gfp = GFP_KERNEL | (nowarn ? __GFP_NOWARN : 0);
+ unsigned long fallback_start = 0, fallback_end = 0;
+ unsigned long start, end;
/*
- * Don't do huge page allocations for modules yet until more testing
- * is done. STRICT_MODULE_RWX may require extra work to support this
- * too.
+ * BOOK3S_32 and 8xx define MODULES_VADDR for text allocations and
+ * allow allocating data in the entire vmalloc space
*/
- return __vmalloc_node_range(size, 1, start, end, gfp, prot,
- VM_FLUSH_RESET_PERMS,
- NUMA_NO_NODE, __builtin_return_address(0));
-}
-
-void *module_alloc(unsigned long size)
-{
#ifdef MODULES_VADDR
unsigned long limit = (unsigned long)_etext - SZ_32M;
- void *ptr = NULL;
BUILD_BUG_ON(TASK_SIZE > MODULES_VADDR);
/* First try within 32M limit from _etext to avoid branch trampolines */
- if (MODULES_VADDR < PAGE_OFFSET && MODULES_END > limit)
- ptr = __module_alloc(size, limit, MODULES_END, true);
-
- if (!ptr)
- ptr = __module_alloc(size, MODULES_VADDR, MODULES_END, false);
+ if (MODULES_VADDR < PAGE_OFFSET && MODULES_END > limit) {
+ start = limit;
+ fallback_start = MODULES_VADDR;
+ fallback_end = MODULES_END;
+ } else {
+ start = MODULES_VADDR;
+ }
- return ptr;
+ end = MODULES_END;
#else
- return __module_alloc(size, VMALLOC_START, VMALLOC_END, false);
+ start = VMALLOC_START;
+ end = VMALLOC_END;
#endif
+
+ execmem_info = (struct execmem_info){
+ .ranges = {
+ [EXECMEM_DEFAULT] = {
+ .start = start,
+ .end = end,
+ .pgprot = prot,
+ .alignment = 1,
+ .fallback_start = fallback_start,
+ .fallback_end = fallback_end,
+ },
+ [EXECMEM_MODULE_DATA] = {
+ .start = VMALLOC_START,
+ .end = VMALLOC_END,
+ .pgprot = PAGE_KERNEL,
+ .alignment = 1,
+ },
+ },
+ };
+
+ return &execmem_info;
}
@@ -37,41 +37,31 @@
#define PLT_ENTRY_SIZE 22
-static unsigned long get_module_load_offset(void)
+static struct execmem_info execmem_info __ro_after_init;
+
+struct execmem_info __init *execmem_arch_setup(void)
{
- static DEFINE_MUTEX(module_kaslr_mutex);
- static unsigned long module_load_offset;
-
- if (!kaslr_enabled())
- return 0;
- /*
- * Calculate the module_load_offset the first time this code
- * is called. Once calculated it stays the same until reboot.
- */
- mutex_lock(&module_kaslr_mutex);
- if (!module_load_offset)
+ unsigned long module_load_offset = 0;
+ unsigned long start;
+
+ if (kaslr_enabled())
module_load_offset = get_random_u32_inclusive(1, 1024) * PAGE_SIZE;
- mutex_unlock(&module_kaslr_mutex);
- return module_load_offset;
-}
-void *module_alloc(unsigned long size)
-{
- gfp_t gfp_mask = GFP_KERNEL;
- void *p;
-
- if (PAGE_ALIGN(size) > MODULES_LEN)
- return NULL;
- p = __vmalloc_node_range(size, MODULE_ALIGN,
- MODULES_VADDR + get_module_load_offset(),
- MODULES_END, gfp_mask, PAGE_KERNEL,
- VM_FLUSH_RESET_PERMS | VM_DEFER_KMEMLEAK,
- NUMA_NO_NODE, __builtin_return_address(0));
- if (p && (kasan_alloc_module_shadow(p, size, gfp_mask) < 0)) {
- vfree(p);
- return NULL;
- }
- return p;
+ start = MODULES_VADDR + module_load_offset;
+
+ execmem_info = (struct execmem_info){
+ .ranges = {
+ [EXECMEM_DEFAULT] = {
+ .flags = EXECMEM_KASAN_SHADOW,
+ .start = start,
+ .end = MODULES_END,
+ .pgprot = PAGE_KERNEL,
+ .alignment = MODULE_ALIGN,
+ },
+ },
+ };
+
+ return &execmem_info;
}
#ifdef CONFIG_FUNCTION_TRACER
@@ -19,6 +19,7 @@
#include <linux/jump_label.h>
#include <linux/random.h>
#include <linux/memory.h>
+#include <linux/execmem.h>
#include <asm/text-patching.h>
#include <asm/page.h>
@@ -36,55 +37,30 @@ do { \
} while (0)
#endif
-#ifdef CONFIG_RANDOMIZE_BASE
-static unsigned long module_load_offset;
+static struct execmem_info execmem_info __ro_after_init;
-/* Mutex protects the module_load_offset. */
-static DEFINE_MUTEX(module_kaslr_mutex);
-
-static unsigned long int get_module_load_offset(void)
-{
- if (kaslr_enabled()) {
- mutex_lock(&module_kaslr_mutex);
- /*
- * Calculate the module_load_offset the first time this
- * code is called. Once calculated it stays the same until
- * reboot.
- */
- if (module_load_offset == 0)
- module_load_offset =
- get_random_u32_inclusive(1, 1024) * PAGE_SIZE;
- mutex_unlock(&module_kaslr_mutex);
- }
- return module_load_offset;
-}
-#else
-static unsigned long int get_module_load_offset(void)
+struct execmem_info __init *execmem_arch_setup(void)
{
- return 0;
-}
-#endif
-
-void *module_alloc(unsigned long size)
-{
- gfp_t gfp_mask = GFP_KERNEL;
- void *p;
-
- if (PAGE_ALIGN(size) > MODULES_LEN)
- return NULL;
-
- p = __vmalloc_node_range(size, MODULE_ALIGN,
- MODULES_VADDR + get_module_load_offset(),
- MODULES_END, gfp_mask, PAGE_KERNEL,
- VM_FLUSH_RESET_PERMS | VM_DEFER_KMEMLEAK,
- NUMA_NO_NODE, __builtin_return_address(0));
-
- if (p && (kasan_alloc_module_shadow(p, size, gfp_mask) < 0)) {
- vfree(p);
- return NULL;
- }
-
- return p;
+ unsigned long start, offset = 0;
+
+ if (kaslr_enabled())
+ offset = get_random_u32_inclusive(1, 1024) * PAGE_SIZE;
+
+ start = MODULES_VADDR + offset;
+
+ execmem_info = (struct execmem_info){
+ .ranges = {
+ [EXECMEM_DEFAULT] = {
+ .flags = EXECMEM_KASAN_SHADOW,
+ .start = start,
+ .end = MODULES_END,
+ .pgprot = PAGE_KERNEL,
+ .alignment = MODULE_ALIGN,
+ },
+ },
+ };
+
+ return &execmem_info;
}
#ifdef CONFIG_X86_32
@@ -5,6 +5,14 @@
#include <linux/types.h>
#include <linux/moduleloader.h>
+#if (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)) && \
+ !defined(CONFIG_KASAN_VMALLOC)
+#include <linux/kasan.h>
+#define MODULE_ALIGN (PAGE_SIZE << KASAN_SHADOW_SCALE_SHIFT)
+#else
+#define MODULE_ALIGN PAGE_SIZE
+#endif
+
/**
* enum execmem_type - types of executable memory ranges
*
@@ -22,6 +30,7 @@
* @EXECMEM_KPROBES: parameters for kprobes
* @EXECMEM_FTRACE: parameters for ftrace
* @EXECMEM_BPF: parameters for BPF
+ * @EXECMEM_MODULE_DATA: parameters for module data sections
* @EXECMEM_TYPE_MAX:
*/
enum execmem_type {
@@ -30,22 +39,38 @@ enum execmem_type {
EXECMEM_KPROBES,
EXECMEM_FTRACE,
EXECMEM_BPF,
+ EXECMEM_MODULE_DATA,
EXECMEM_TYPE_MAX,
};
+/**
+ * enum execmem_range_flags - options for executable memory allocations
+ * @EXECMEM_KASAN_SHADOW: allocate kasan shadow
+ */
+enum execmem_range_flags {
+ EXECMEM_KASAN_SHADOW = (1 << 0),
+};
+
/**
* struct execmem_range - definition of an address space suitable for code and
* related data allocations
* @start: address space start
* @end: address space end (inclusive)
+ * @fallback_start: start of the secondary address space range for fallback
+ * allocations on architectures that require it
+ * @fallback_end: start of the secondary address space (inclusive)
* @pgprot: permissions for memory in this address space
* @alignment: alignment required for text allocations
+ * @flags: options for memory allocations for this range
*/
struct execmem_range {
unsigned long start;
unsigned long end;
+ unsigned long fallback_start;
+ unsigned long fallback_end;
pgprot_t pgprot;
unsigned int alignment;
+ enum execmem_range_flags flags;
};
/**
@@ -82,6 +107,9 @@ struct execmem_info *execmem_arch_setup(void);
* Allocates memory that will contain executable code, either generated or
* loaded from kernel modules.
*
+ * Allocates memory that will contain data coupled with executable code,
+ * like data sections in kernel modules.
+ *
* The memory will have protections defined by architecture for executable
* region of the @type.
*
@@ -95,7 +123,7 @@ void *execmem_alloc(enum execmem_type type, size_t size);
*/
void execmem_free(void *ptr);
-#ifdef CONFIG_EXECMEM
+#if defined(CONFIG_EXECMEM) && !defined(CONFIG_ARCH_WANTS_EXECMEM_LATE)
void execmem_init(void);
#else
static inline void execmem_init(void) {}
@@ -25,10 +25,6 @@ int module_frob_arch_sections(Elf_Ehdr *hdr,
/* Additional bytes needed by arch in front of individual sections */
unsigned int arch_mod_section_prepend(struct module *mod, unsigned int section);
-/* Allocator used for allocating struct module, core sections and init
- sections. Returns NULL on failure. */
-void *module_alloc(unsigned long size);
-
/* Determines if the section name is an init section (that is only used during
* module loading).
*/
@@ -126,12 +122,4 @@ void module_arch_cleanup(struct module *mod);
/* Any cleanup before freeing mod->module_init */
void module_arch_freeing_init(struct module *mod);
-#if (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)) && \
- !defined(CONFIG_KASAN_VMALLOC)
-#include <linux/kasan.h>
-#define MODULE_ALIGN (PAGE_SIZE << KASAN_SHADOW_SCALE_SHIFT)
-#else
-#define MODULE_ALIGN PAGE_SIZE
-#endif
-
#endif
@@ -1188,24 +1188,20 @@ void __weak module_arch_freeing_init(struct module *mod)
{
}
-static bool mod_mem_use_vmalloc(enum mod_mem_type type)
-{
- return IS_ENABLED(CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC) &&
- mod_mem_type_is_core_data(type);
-}
-
static int module_memory_alloc(struct module *mod, enum mod_mem_type type)
{
unsigned int size = PAGE_ALIGN(mod->mem[type].size);
+ enum execmem_type execmem_type;
void *ptr;
mod->mem[type].size = size;
- if (mod_mem_use_vmalloc(type))
- ptr = vmalloc(size);
+ if (mod_mem_type_is_data(type))
+ execmem_type = EXECMEM_MODULE_DATA;
else
- ptr = execmem_alloc(EXECMEM_MODULE_TEXT, size);
+ execmem_type = EXECMEM_MODULE_TEXT;
+ ptr = execmem_alloc(execmem_type, size);
if (!ptr)
return -ENOMEM;
@@ -1232,10 +1228,7 @@ static void module_memory_free(struct module *mod, enum mod_mem_type type)
{
void *ptr = mod->mem[type].base;
- if (mod_mem_use_vmalloc(type))
- vfree(ptr);
- else
- execmem_free(ptr);
+ execmem_free(ptr);
}
static void free_mod_mem(struct module *mod)
@@ -1630,13 +1623,6 @@ static void free_modinfo(struct module *mod)
}
}
-void * __weak module_alloc(unsigned long size)
-{
- return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
- GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
- NUMA_NO_NODE, __builtin_return_address(0));
-}
-
bool __weak module_init_section(const char *name)
{
return strstarts(name, ".init");
@@ -12,27 +12,49 @@
#include <linux/moduleloader.h>
static struct execmem_info *execmem_info __ro_after_init;
+static struct execmem_info default_execmem_info __ro_after_init;
static void *__execmem_alloc(struct execmem_range *range, size_t size)
{
+ bool kasan = range->flags & EXECMEM_KASAN_SHADOW;
+ unsigned long vm_flags = VM_FLUSH_RESET_PERMS;
+ gfp_t gfp_flags = GFP_KERNEL | __GFP_NOWARN;
unsigned long start = range->start;
unsigned long end = range->end;
unsigned int align = range->alignment;
pgprot_t pgprot = range->pgprot;
+ void *p;
+
+ if (kasan)
+ vm_flags |= VM_DEFER_KMEMLEAK;
+
+ p = __vmalloc_node_range(size, align, start, end, gfp_flags,
+ pgprot, vm_flags, NUMA_NO_NODE,
+ __builtin_return_address(0));
+ if (!p && range->fallback_start) {
+ start = range->fallback_start;
+ end = range->fallback_end;
+ p = __vmalloc_node_range(size, align, start, end, gfp_flags,
+ pgprot, vm_flags, NUMA_NO_NODE,
+ __builtin_return_address(0));
+ }
+
+ if (!p) {
+ pr_warn_ratelimited("execmem: unable to allocate memory\n");
+ return NULL;
+ }
+
+ if (kasan && (kasan_alloc_module_shadow(p, size, GFP_KERNEL) < 0)) {
+ vfree(p);
+ return NULL;
+ }
- return __vmalloc_node_range(size, align, start, end,
- GFP_KERNEL, pgprot, VM_FLUSH_RESET_PERMS,
- NUMA_NO_NODE, __builtin_return_address(0));
+ return kasan_reset_tag(p);
}
void *execmem_alloc(enum execmem_type type, size_t size)
{
- struct execmem_range *range;
-
- if (!execmem_info)
- return module_alloc(size);
-
- range = &execmem_info->ranges[type];
+ struct execmem_range *range = &execmem_info->ranges[type];
return __execmem_alloc(range, size);
}
@@ -67,10 +89,16 @@ static void execmem_init_missing(struct execmem_info *info)
struct execmem_range *r = &info->ranges[i];
if (!r->start) {
- r->pgprot = default_range->pgprot;
+ if (i == EXECMEM_MODULE_DATA)
+ r->pgprot = PAGE_KERNEL;
+ else
+ r->pgprot = default_range->pgprot;
r->alignment = default_range->alignment;
r->start = default_range->start;
r->end = default_range->end;
+ r->flags = default_range->flags;
+ r->fallback_start = default_range->fallback_start;
+ r->fallback_end = default_range->fallback_end;
}
}
}
@@ -80,14 +108,37 @@ struct execmem_info * __weak execmem_arch_setup(void)
return NULL;
}
-void __init execmem_init(void)
+static void __init __execmem_init(void)
{
struct execmem_info *info = execmem_arch_setup();
- if (!info || !execmem_validate(info))
+ if (!info) {
+ info = execmem_info = &default_execmem_info;
+ info->ranges[EXECMEM_DEFAULT].start = VMALLOC_START;
+ info->ranges[EXECMEM_DEFAULT].end = VMALLOC_END;
+ info->ranges[EXECMEM_DEFAULT].pgprot = PAGE_KERNEL_EXEC;
+ info->ranges[EXECMEM_DEFAULT].alignment = 1;
+ return;
+ }
+
+ if (!execmem_validate(info))
return;
execmem_init_missing(info);
execmem_info = info;
}
+
+#ifdef CONFIG_ARCH_WANTS_EXECMEM_LATE
+static int __init execmem_late_init(void)
+{
+ __execmem_init();
+ return 0;
+}
+core_initcall(execmem_late_init);
+#else
+void __init execmem_init(void)
+{
+ __execmem_init();
+}
+#endif