[v3,02/13] mm: introduce execmem_text_alloc() and execmem_free()

diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index b20ee72e873a..62228c7072a2 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -19,8 +19,8 @@ 
 #include <linux/extable.h>
 #include <linux/kdebug.h>
 #include <linux/slab.h>
-#include <linux/moduleloader.h>
 #include <linux/set_memory.h>
+#include <linux/execmem.h>
 #include <asm/code-patching.h>
 #include <asm/cacheflush.h>
 #include <asm/sstep.h>
@@ -130,7 +130,7 @@  void *alloc_insn_page(void)
 {
 	void *page;
 
-	page = module_alloc(PAGE_SIZE);
+	page = execmem_text_alloc(EXECMEM_KPROBES, PAGE_SIZE);
 	if (!page)
 		return NULL;
 
diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c
index c46381ea04ec..4052e10eb6a4 100644
--- a/arch/s390/kernel/ftrace.c
+++ b/arch/s390/kernel/ftrace.c
@@ -7,13 +7,13 @@ 
  *   Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
  */
 
-#include <linux/moduleloader.h>
 #include <linux/hardirq.h>
 #include <linux/uaccess.h>
 #include <linux/ftrace.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/kprobes.h>
+#include <linux/execmem.h>
 #include <trace/syscall.h>
 #include <asm/asm-offsets.h>
 #include <asm/text-patching.h>
@@ -220,7 +220,7 @@  static int __init ftrace_plt_init(void)
 {
 	const char *start, *end;
 
-	ftrace_plt = module_alloc(PAGE_SIZE);
+	ftrace_plt = execmem_text_alloc(EXECMEM_FTRACE, PAGE_SIZE);
 	if (!ftrace_plt)
 		panic("cannot allocate ftrace plt\n");
 
diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c
index d4b863ed0aa7..48928460dcb9 100644
--- a/arch/s390/kernel/kprobes.c
+++ b/arch/s390/kernel/kprobes.c
@@ -9,7 +9,6 @@ 
 
 #define pr_fmt(fmt) "kprobes: " fmt
 
-#include <linux/moduleloader.h>
 #include <linux/kprobes.h>
 #include <linux/ptrace.h>
 #include <linux/preempt.h>
@@ -21,6 +20,7 @@ 
 #include <linux/slab.h>
 #include <linux/hardirq.h>
 #include <linux/ftrace.h>
+#include <linux/execmem.h>
 #include <asm/set_memory.h>
 #include <asm/sections.h>
 #include <asm/dis.h>
@@ -38,7 +38,7 @@  void *alloc_insn_page(void)
 {
 	void *page;
 
-	page = module_alloc(PAGE_SIZE);
+	page = execmem_text_alloc(EXECMEM_KPROBES, PAGE_SIZE);
 	if (!page)
 		return NULL;
 	set_memory_rox((unsigned long)page, 1);
diff --git a/arch/s390/kernel/module.c b/arch/s390/kernel/module.c
index 42215f9404af..db5561d0c233 100644
--- a/arch/s390/kernel/module.c
+++ b/arch/s390/kernel/module.c
@@ -21,6 +21,7 @@ 
 #include <linux/moduleloader.h>
 #include <linux/bug.h>
 #include <linux/memory.h>
+#include <linux/execmem.h>
 #include <asm/alternative.h>
 #include <asm/nospec-branch.h>
 #include <asm/facility.h>
@@ -76,7 +77,7 @@  void *module_alloc(unsigned long size)
 #ifdef CONFIG_FUNCTION_TRACER
 void module_arch_cleanup(struct module *mod)
 {
-	module_memfree(mod->arch.trampolines_start);
+	execmem_free(mod->arch.trampolines_start);
 }
 #endif
 
@@ -510,7 +511,7 @@  static int module_alloc_ftrace_hotpatch_trampolines(struct module *me,
 
 	size = FTRACE_HOTPATCH_TRAMPOLINES_SIZE(s->sh_size);
 	numpages = DIV_ROUND_UP(size, PAGE_SIZE);
-	start = module_alloc(numpages * PAGE_SIZE);
+	start = execmem_text_alloc(EXECMEM_FTRACE, numpages * PAGE_SIZE);
 	if (!start)
 		return -ENOMEM;
 	set_memory_rox((unsigned long)start, numpages);
diff --git a/arch/sparc/net/bpf_jit_comp_32.c b/arch/sparc/net/bpf_jit_comp_32.c
index a74e5004c6c8..5fa9c45fba0a 100644
--- a/arch/sparc/net/bpf_jit_comp_32.c
+++ b/arch/sparc/net/bpf_jit_comp_32.c
@@ -1,10 +1,10 @@ 
 // SPDX-License-Identifier: GPL-2.0
-#include <linux/moduleloader.h>
 #include <linux/workqueue.h>
 #include <linux/netdevice.h>
 #include <linux/filter.h>
 #include <linux/cache.h>
 #include <linux/if_vlan.h>
+#include <linux/execmem.h>
 
 #include <asm/cacheflush.h>
 #include <asm/ptrace.h>
@@ -713,7 +713,7 @@  cond_branch:			f_offset = addrs[i + filter[i].jf];
 				if (unlikely(proglen + ilen > oldproglen)) {
 					pr_err("bpb_jit_compile fatal error\n");
 					kfree(addrs);
-					module_memfree(image);
+					execmem_free(image);
 					return;
 				}
 				memcpy(image + proglen, temp, ilen);
@@ -736,7 +736,7 @@  cond_branch:			f_offset = addrs[i + filter[i].jf];
 			break;
 		}
 		if (proglen == oldproglen) {
-			image = module_alloc(proglen);
+			image = execmem_text_alloc(EXECMEM_BPF, proglen);
 			if (!image)
 				goto out;
 		}
@@ -758,7 +758,7 @@  cond_branch:			f_offset = addrs[i + filter[i].jf];
 void bpf_jit_free(struct bpf_prog *fp)
 {
 	if (fp->jited)
-		module_memfree(fp->bpf_func);
+		execmem_free(fp->bpf_func);
 
 	bpf_prog_unlock_free(fp);
 }
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 12df54ff0e81..ae56d79a6a74 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -25,6 +25,7 @@ 
 #include <linux/memory.h>
 #include <linux/vmalloc.h>
 #include <linux/set_memory.h>
+#include <linux/execmem.h>
 
 #include <trace/syscall.h>
 
@@ -261,15 +262,14 @@  void arch_ftrace_update_code(int command)
 #ifdef CONFIG_X86_64
 
 #ifdef CONFIG_MODULES
-#include <linux/moduleloader.h>
 /* Module allocation simplifies allocating memory for code */
 static inline void *alloc_tramp(unsigned long size)
 {
-	return module_alloc(size);
+	return execmem_text_alloc(EXECMEM_FTRACE, size);
 }
 static inline void tramp_free(void *tramp)
 {
-	module_memfree(tramp);
+	execmem_free(tramp);
 }
 #else
 /* Trampolines can only be created if modules are supported */
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index e8babebad7b8..c4f58e893efd 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -40,12 +40,12 @@ 
 #include <linux/kgdb.h>
 #include <linux/ftrace.h>
 #include <linux/kasan.h>
-#include <linux/moduleloader.h>
 #include <linux/objtool.h>
 #include <linux/vmalloc.h>
 #include <linux/pgtable.h>
 #include <linux/set_memory.h>
 #include <linux/cfi.h>
+#include <linux/execmem.h>
 
 #include <asm/text-patching.h>
 #include <asm/cacheflush.h>
@@ -448,7 +448,7 @@  void *alloc_insn_page(void)
 {
 	void *page;
 
-	page = module_alloc(PAGE_SIZE);
+	page = execmem_text_alloc(EXECMEM_KPROBES, PAGE_SIZE);
 	if (!page)
 		return NULL;
 
diff --git a/include/linux/execmem.h b/include/linux/execmem.h
new file mode 100644
index 000000000000..3491bf7e9714
--- /dev/null
+++ b/include/linux/execmem.h
@@ -0,0 +1,56 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_EXECMEM_ALLOC_H
+#define _LINUX_EXECMEM_ALLOC_H
+
+#include <linux/types.h>
+
+/**
+ * enum execmem_type - types of executable memory ranges
+ *
+ * There are several subsystems that allocate executable memory.
+ * Architectures define different restrictions on placement,
+ * permissions, alignment and other parameters for memory that can be used
+ * by these subsystems.
+ * Types in this enum identify subsystems that allocate executable memory
+ * and let architectures define parameters for ranges suitable for
+ * allocations by each subsystem.
+ *
+ * @EXECMEM_DEFAULT: default parameters that would be used for types that
+ * are not explcitly defined.
+ * @EXECMEM_MODULE_TEXT: parameters for module text sections
+ * @EXECMEM_KPROBES: parameters for kprobes
+ * @EXECMEM_FTRACE: parameters for ftrace
+ * @EXECMEM_BPF: parameters for BPF
+ * @EXECMEM_TYPE_MAX:
+ */
+enum execmem_type {
+	EXECMEM_DEFAULT,
+	EXECMEM_MODULE_TEXT = EXECMEM_DEFAULT,
+	EXECMEM_KPROBES,
+	EXECMEM_FTRACE,
+	EXECMEM_BPF,
+	EXECMEM_TYPE_MAX,
+};
+
+/**
+ * execmem_text_alloc - allocate executable memory
+ * @type: type of the allocation
+ * @size: how many bytes of memory are required
+ *
+ * Allocates memory that will contain executable code, either generated or
+ * loaded from kernel modules.
+ *
+ * The memory will have protections defined by architecture for executable
+ * region of the @type.
+ *
+ * Return: a pointer to the allocated memory or %NULL
+ */
+void *execmem_text_alloc(enum execmem_type type, size_t size);
+
+/**
+ * execmem_free - free executable memory
+ * @ptr: pointer to the memory that should be freed
+ */
+void execmem_free(void *ptr);
+
+#endif /* _LINUX_EXECMEM_ALLOC_H */
diff --git a/include/linux/moduleloader.h b/include/linux/moduleloader.h
index 001b2ce83832..a23718aa2f4d 100644
--- a/include/linux/moduleloader.h
+++ b/include/linux/moduleloader.h
@@ -29,9 +29,6 @@  unsigned int arch_mod_section_prepend(struct module *mod, unsigned int section);
    sections.  Returns NULL on failure. */
 void *module_alloc(unsigned long size);
 
-/* Free memory returned from module_alloc. */
-void module_memfree(void *module_region);
-
 /* Determines if the section name is an init section (that is only used during
  * module loading).
  */
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 4e3ce0542e31..75249f2d9f77 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -22,7 +22,6 @@ 
 #include <linux/skbuff.h>
 #include <linux/vmalloc.h>
 #include <linux/random.h>
-#include <linux/moduleloader.h>
 #include <linux/bpf.h>
 #include <linux/btf.h>
 #include <linux/objtool.h>
@@ -37,6 +36,7 @@ 
 #include <linux/nospec.h>
 #include <linux/bpf_mem_alloc.h>
 #include <linux/memcontrol.h>
+#include <linux/execmem.h>
 
 #include <asm/barrier.h>
 #include <asm/unaligned.h>
@@ -1007,12 +1007,12 @@  void bpf_jit_uncharge_modmem(u32 size)
 
 void *__weak bpf_jit_alloc_exec(unsigned long size)
 {
-	return module_alloc(size);
+	return execmem_text_alloc(EXECMEM_BPF, size);
 }
 
 void __weak bpf_jit_free_exec(void *addr)
 {
-	module_memfree(addr);
+	execmem_free(addr);
 }
 
 struct bpf_binary_header *
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 0c6185aefaef..0ccb4d2ec9a2 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -26,7 +26,6 @@ 
 #include <linux/slab.h>
 #include <linux/stddef.h>
 #include <linux/export.h>
-#include <linux/moduleloader.h>
 #include <linux/kallsyms.h>
 #include <linux/freezer.h>
 #include <linux/seq_file.h>
@@ -39,6 +38,7 @@ 
 #include <linux/jump_label.h>
 #include <linux/static_call.h>
 #include <linux/perf_event.h>
+#include <linux/execmem.h>
 
 #include <asm/sections.h>
 #include <asm/cacheflush.h>
@@ -113,17 +113,17 @@  enum kprobe_slot_state {
 void __weak *alloc_insn_page(void)
 {
 	/*
-	 * Use module_alloc() so this page is within +/- 2GB of where the
+	 * Use execmem_text_alloc() so this page is within +/- 2GB of where the
 	 * kernel image and loaded module images reside. This is required
 	 * for most of the architectures.
 	 * (e.g. x86-64 needs this to handle the %rip-relative fixups.)
 	 */
-	return module_alloc(PAGE_SIZE);
+	return execmem_text_alloc(EXECMEM_KPROBES, PAGE_SIZE);
 }
 
 static void free_insn_page(void *page)
 {
-	module_memfree(page);
+	execmem_free(page);
 }
 
 struct kprobe_insn_cache kprobe_insn_slots = {
diff --git a/kernel/module/Kconfig b/kernel/module/Kconfig
index 33a2e991f608..813e116bdee6 100644
--- a/kernel/module/Kconfig
+++ b/kernel/module/Kconfig
@@ -2,6 +2,7 @@ 
 menuconfig MODULES
 	bool "Enable loadable module support"
 	modules
+	select EXECMEM
 	help
 	  Kernel modules are small pieces of compiled code which can
 	  be inserted in the running kernel, rather than being
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 98fedfdb8db5..4ec982cc943c 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -57,6 +57,7 @@ 
 #include <linux/audit.h>
 #include <linux/cfi.h>
 #include <linux/debugfs.h>
+#include <linux/execmem.h>
 #include <uapi/linux/module.h>
 #include "internal.h"
 
@@ -1179,16 +1180,6 @@  resolve_symbol_wait(struct module *mod,
 	return ksym;
 }
 
-void __weak module_memfree(void *module_region)
-{
-	/*
-	 * This memory may be RO, and freeing RO memory in an interrupt is not
-	 * supported by vmalloc.
-	 */
-	WARN_ON(in_interrupt());
-	vfree(module_region);
-}
-
 void __weak module_arch_cleanup(struct module *mod)
 {
 }
@@ -1207,7 +1198,7 @@  static void *module_memory_alloc(unsigned int size, enum mod_mem_type type)
 {
 	if (mod_mem_use_vmalloc(type))
 		return vzalloc(size);
-	return module_alloc(size);
+	return execmem_text_alloc(EXECMEM_MODULE_TEXT, size);
 }
 
 static void module_memory_free(void *ptr, enum mod_mem_type type)
@@ -1215,7 +1206,7 @@  static void module_memory_free(void *ptr, enum mod_mem_type type)
 	if (mod_mem_use_vmalloc(type))
 		vfree(ptr);
 	else
-		module_memfree(ptr);
+		execmem_free(ptr);
 }
 
 static void free_mod_mem(struct module *mod)
@@ -2479,9 +2470,9 @@  static void do_free_init(struct work_struct *w)
 
 	llist_for_each_safe(pos, n, list) {
 		initfree = container_of(pos, struct mod_initfree, node);
-		module_memfree(initfree->init_text);
-		module_memfree(initfree->init_data);
-		module_memfree(initfree->init_rodata);
+		execmem_free(initfree->init_text);
+		execmem_free(initfree->init_data);
+		execmem_free(initfree->init_rodata);
 		kfree(initfree);
 	}
 }
@@ -2584,10 +2575,10 @@  static noinline int do_init_module(struct module *mod)
 	 * We want to free module_init, but be aware that kallsyms may be
 	 * walking this with preempt disabled.  In all the failure paths, we
 	 * call synchronize_rcu(), but we don't want to slow down the success
-	 * path. module_memfree() cannot be called in an interrupt, so do the
+	 * path. execmem_free() cannot be called in an interrupt, so do the
 	 * work and call synchronize_rcu() in a work queue.
 	 *
-	 * Note that module_alloc() on most architectures creates W+X page
+	 * Note that execmem_text_alloc() on most architectures creates W+X page
 	 * mappings which won't be cleaned up until do_free_init() runs.  Any
 	 * code such as mark_rodata_ro() which depends on those mappings to
 	 * be cleaned up needs to sync with the queued work - ie
diff --git a/mm/Kconfig b/mm/Kconfig
index 264a2df5ecf5..fb12931238e8 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -1258,6 +1258,9 @@  config LOCK_MM_AND_FIND_VMA
 	bool
 	depends on !STACK_GROWSUP
 
+config EXECMEM
+	bool
+
 source "mm/damon/Kconfig"
 
 endmenu
diff --git a/mm/Makefile b/mm/Makefile
index ec65984e2ade..2e5fec94f09c 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -138,3 +138,4 @@  obj-$(CONFIG_IO_MAPPING) += io-mapping.o
 obj-$(CONFIG_HAVE_BOOTMEM_INFO_NODE) += bootmem_info.o
 obj-$(CONFIG_GENERIC_IOREMAP) += ioremap.o
 obj-$(CONFIG_SHRINKER_DEBUG) += shrinker_debug.o
+obj-$(CONFIG_EXECMEM) += execmem.o
diff --git a/mm/execmem.c b/mm/execmem.c
new file mode 100644
index 000000000000..638dc2b26a81
--- /dev/null
+++ b/mm/execmem.c
@@ -0,0 +1,26 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
+#include <linux/execmem.h>
+#include <linux/moduleloader.h>
+
+static void *execmem_alloc(size_t size)
+{
+	return module_alloc(size);
+}
+
+void *execmem_text_alloc(enum execmem_type type, size_t size)
+{
+	return execmem_alloc(size);
+}
+
+void execmem_free(void *ptr)
+{
+	/*
+	 * This memory may be RO, and freeing RO memory in an interrupt is not
+	 * supported by vmalloc.
+	 */
+	WARN_ON(in_interrupt());
+	vfree(ptr);
+}