[PATCH v3 03/13] mm/execmem, arch: convert simple overrides of module_alloc... | linux-trace-kernel

[PATCH v3 03/13] mm/execmem, arch: convert simple overrides of module_alloc to execmem

From: Mike Rapoport <rppt@kernel.org>
Date: 2023-09-18 07:52:55
Also in: bpf, linux-arm-kernel, linux-mips, linux-mm, linux-modules, linux-riscv, linux-s390, linuxppc-dev, lkml, loongarch, netdev, sparclinux
Subsystem: loongarch, memblock and memory management initialization, memory management, memory management - execmem, mips, nios2 architecture, parisc architecture, risc-v architecture, sparc + ultrasparc (sparc/sparc64), the rest · Maintainers: Huacai Chen, Mike Rapoport, Andrew Morton, Thomas Bogendoerfer, Dinh Nguyen, Simon Schuster, "James E.J. Bottomley", Helge Deller, Paul Walmsley, Palmer Dabbelt, Albert Ou, "David S. Miller", Andreas Larsson, Linus Torvalds

From: "Mike Rapoport (IBM)" <rppt@kernel.org>

Several architectures override module_alloc() only to define address
range for code allocations different than VMALLOC address space.

Provide a generic implementation in execmem that uses the parameters
for address space ranges, required alignment and page protections
provided by architectures.

The architectures must fill execmem_params structure and implement
execmem_arch_params() that returns a pointer to that structure. This
way the execmem initialization won't be called from every architecture,
but rather from a central place, namely initialization of the core
memory management.

The execmem provides execmem_text_alloc() API that wraps
__vmalloc_node_range() with the parameters defined by the architectures.
If an architecture does not implement execmem_arch_params(),
execmem_text_alloc() will fall back to module_alloc().

The name execmem_text_alloc() emphasizes that the allocated memory is
for executable code, the allocations of the associated data, like data
sections of a module will use execmem_data_alloc() interface that will
be added later.

Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
---
 arch/loongarch/kernel/module.c | 18 ++++++++--
 arch/mips/kernel/module.c      | 19 +++++++---
 arch/nios2/kernel/module.c     | 19 +++++++---
 arch/parisc/kernel/module.c    | 23 +++++++-----
 arch/riscv/kernel/module.c     | 20 ++++++++---
 arch/sparc/kernel/module.c     | 44 +++++++++++------------
 include/linux/execmem.h        | 44 +++++++++++++++++++++++
 mm/execmem.c                   | 66 ++++++++++++++++++++++++++++++++--
 mm/mm_init.c                   |  2 ++
 9 files changed, 203 insertions(+), 52 deletions(-)

diff --git a/arch/loongarch/kernel/module.c b/arch/loongarch/kernel/module.c
index b8b86088b2dd..a1d8fe9796fa 100644
--- a/arch/loongarch/kernel/module.c
+++ b/arch/loongarch/kernel/module.c

@@ -18,6 +18,7 @@
 #include <linux/ftrace.h>
 #include <linux/string.h>
 #include <linux/kernel.h>
+#include <linux/execmem.h>
 #include <asm/alternative.h>
 #include <asm/inst.h>

@@ -469,10 +470,21 @@ int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
 	return 0;
 }
 
-void *module_alloc(unsigned long size)
+static struct execmem_params execmem_params __ro_after_init = {
+	.ranges = {
+		[EXECMEM_DEFAULT] = {
+			.pgprot = PAGE_KERNEL,
+			.alignment = 1,
+		},
+	},
+};
+
+struct execmem_params __init *execmem_arch_params(void)
 {
-	return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
-			GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE, __builtin_return_address(0));
+	execmem_params.ranges[EXECMEM_DEFAULT].start = MODULES_VADDR;
+	execmem_params.ranges[EXECMEM_DEFAULT].end = MODULES_END;
+
+	return &execmem_params;
 }
 
 static void module_init_ftrace_plt(const Elf_Ehdr *hdr,

diff --git a/arch/mips/kernel/module.c b/arch/mips/kernel/module.c
index 0c936cbf20c5..1c959074b35f 100644
--- a/arch/mips/kernel/module.c
+++ b/arch/mips/kernel/module.c

@@ -20,6 +20,7 @@
 #include <linux/kernel.h>
 #include <linux/spinlock.h>
 #include <linux/jump_label.h>
+#include <linux/execmem.h>
 
 extern void jump_label_apply_nops(struct module *mod);

@@ -33,11 +34,21 @@ static LIST_HEAD(dbe_list);
 static DEFINE_SPINLOCK(dbe_lock);
 
 #ifdef MODULE_START
-void *module_alloc(unsigned long size)
+static struct execmem_params execmem_params __ro_after_init = {
+	.ranges = {
+		[EXECMEM_DEFAULT] = {
+			.start = MODULE_START,
+			.end = MODULE_END,
+			.alignment = 1,
+		},
+	},
+};
+
+struct execmem_params __init *execmem_arch_params(void)
 {
-	return __vmalloc_node_range(size, 1, MODULE_START, MODULE_END,
-				GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE,
-				__builtin_return_address(0));
+	execmem_params.ranges[EXECMEM_DEFAULT].pgprot = PAGE_KERNEL;
+
+	return &execmem_params;
 }
 #endif

diff --git a/arch/nios2/kernel/module.c b/arch/nios2/kernel/module.c
index 9c97b7513853..5a8df4f9c04e 100644
--- a/arch/nios2/kernel/module.c
+++ b/arch/nios2/kernel/module.c

@@ -18,15 +18,24 @@
 #include <linux/fs.h>
 #include <linux/string.h>
 #include <linux/kernel.h>
+#include <linux/execmem.h>
 
 #include <asm/cacheflush.h>
 
-void *module_alloc(unsigned long size)
+static struct execmem_params execmem_params __ro_after_init = {
+	.ranges = {
+		[EXECMEM_DEFAULT] = {
+			.start = MODULES_VADDR,
+			.end = MODULES_END,
+			.pgprot = PAGE_KERNEL_EXEC,
+			.alignment = 1,
+		},
+	},
+};
+
+struct execmem_params __init *execmem_arch_params(void)
 {
-	return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
-				    GFP_KERNEL, PAGE_KERNEL_EXEC,
-				    VM_FLUSH_RESET_PERMS, NUMA_NO_NODE,
-				    __builtin_return_address(0));
+	return &execmem_params;
 }
 
 int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,

diff --git a/arch/parisc/kernel/module.c b/arch/parisc/kernel/module.c
index d214bbe3c2af..0c6dfd1daef3 100644
--- a/arch/parisc/kernel/module.c
+++ b/arch/parisc/kernel/module.c

@@ -49,6 +49,7 @@
 #include <linux/bug.h>
 #include <linux/mm.h>
 #include <linux/slab.h>
+#include <linux/execmem.h>
 
 #include <asm/unwind.h>
 #include <asm/sections.h>

@@ -173,15 +174,21 @@ static inline int reassemble_22(int as22)
 		((as22 & 0x0003ff) << 3));
 }
 
-void *module_alloc(unsigned long size)
+static struct execmem_params execmem_params __ro_after_init = {
+	.ranges = {
+		[EXECMEM_DEFAULT] = {
+			.pgprot = PAGE_KERNEL_RWX,
+			.alignment = 1,
+		},
+	},
+};
+
+struct execmem_params __init *execmem_arch_params(void)
 {
-	/* using RWX means less protection for modules, but it's
-	 * easier than trying to map the text, data, init_text and
-	 * init_data correctly */
-	return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
-				    GFP_KERNEL,
-				    PAGE_KERNEL_RWX, 0, NUMA_NO_NODE,
-				    __builtin_return_address(0));
+	execmem_params.ranges[EXECMEM_DEFAULT].start = VMALLOC_START;
+	execmem_params.ranges[EXECMEM_DEFAULT].end = VMALLOC_END;
+
+	return &execmem_params;
 }
 
 #ifndef CONFIG_64BIT

diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c
index 7c651d55fcbd..343a0edfb6dd 100644
--- a/arch/riscv/kernel/module.c
+++ b/arch/riscv/kernel/module.c

@@ -11,6 +11,7 @@
 #include <linux/vmalloc.h>
 #include <linux/sizes.h>
 #include <linux/pgtable.h>
+#include <linux/execmem.h>
 #include <asm/alternative.h>
 #include <asm/sections.h>

@@ -436,12 +437,21 @@ int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
 }
 
 #if defined(CONFIG_MMU) && defined(CONFIG_64BIT)
-void *module_alloc(unsigned long size)
+static struct execmem_params execmem_params __ro_after_init = {
+	.ranges = {
+		[EXECMEM_DEFAULT] = {
+			.pgprot = PAGE_KERNEL,
+			.alignment = 1,
+		},
+	},
+};
+
+struct execmem_params __init *execmem_arch_params(void)
 {
-	return __vmalloc_node_range(size, 1, MODULES_VADDR,
-				    MODULES_END, GFP_KERNEL,
-				    PAGE_KERNEL, 0, NUMA_NO_NODE,
-				    __builtin_return_address(0));
+	execmem_params.ranges[EXECMEM_DEFAULT].start = MODULES_VADDR;
+	execmem_params.ranges[EXECMEM_DEFAULT].end = MODULES_END;
+
+	return &execmem_params;
 }
 #endif

diff --git a/arch/sparc/kernel/module.c b/arch/sparc/kernel/module.c
index 66c45a2764bc..1d8d1fba95b9 100644
--- a/arch/sparc/kernel/module.c
+++ b/arch/sparc/kernel/module.c

@@ -14,6 +14,10 @@
 #include <linux/string.h>
 #include <linux/ctype.h>
 #include <linux/mm.h>
+#include <linux/execmem.h>
+#ifdef CONFIG_SPARC64
+#include <linux/jump_label.h>
+#endif
 
 #include <asm/processor.h>
 #include <asm/spitfire.h>

@@ -21,34 +25,26 @@
 
 #include "entry.h"
 
+static struct execmem_params execmem_params __ro_after_init = {
+	.ranges = {
+		[EXECMEM_DEFAULT] = {
 #ifdef CONFIG_SPARC64
-
-#include <linux/jump_label.h>
-
-static void *module_map(unsigned long size)
-{
-	if (PAGE_ALIGN(size) > MODULES_LEN)
-		return NULL;
-	return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
-				GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE,
-				__builtin_return_address(0));
-}
+			.start = MODULES_VADDR,
+			.end = MODULES_END,
 #else
-static void *module_map(unsigned long size)
-{
-	return vmalloc(size);
-}
-#endif /* CONFIG_SPARC64 */
-
-void *module_alloc(unsigned long size)
+			.start = VMALLOC_START,
+			.end = VMALLOC_END,
+#endif
+			.alignment = 1,
+		},
+	},
+};
+
+struct execmem_params __init *execmem_arch_params(void)
 {
-	void *ret;
-
-	ret = module_map(size);
-	if (ret)
-		memset(ret, 0, size);
+	execmem_params.ranges[EXECMEM_DEFAULT].pgprot = PAGE_KERNEL;
 
-	return ret;
+	return &execmem_params;
 }
 
 /* Make generic code ignore STT_REGISTER dummy undefined symbols.  */

diff --git a/include/linux/execmem.h b/include/linux/execmem.h
index 3491bf7e9714..44e213625053 100644
--- a/include/linux/execmem.h
+++ b/include/linux/execmem.h

@@ -32,6 +32,44 @@ enum execmem_type {
 	EXECMEM_TYPE_MAX,
 };
 
+/**
+ * struct execmem_range - definition of a memory range suitable for code and
+ *			  related data allocations
+ * @start:	address space start
+ * @end:	address space end (inclusive)
+ * @pgprot:	permissions for memory in this address space
+ * @alignment:	alignment required for text allocations
+ */
+struct execmem_range {
+	unsigned long   start;
+	unsigned long   end;
+	pgprot_t        pgprot;
+	unsigned int	alignment;
+};
+
+/**
+ * struct execmem_params - architecture parameters for code allocations
+ * @ranges: array of ranges defining architecture specific parameters for
+ * each type of executable memory allocations
+ */
+struct execmem_params {
+	struct execmem_range	ranges[EXECMEM_TYPE_MAX];
+};
+
+/**
+ * execmem_arch_params - supply parameters for allocations of executable memory
+ *
+ * A hook for architectures to define parameters for allocations of
+ * executable memory described by struct execmem_params
+ *
+ * For architectures that do not implement this method a default set of
+ * parameters will be used
+ *
+ * Return: a structure defining architecture parameters and restrictions
+ * for allocations of executable memory
+ */
+struct execmem_params *execmem_arch_params(void);
+
 /**
  * execmem_text_alloc - allocate executable memory
  * @type: type of the allocation

@@ -53,4 +91,10 @@ void *execmem_text_alloc(enum execmem_type type, size_t size);
  */
 void execmem_free(void *ptr);
 
+#ifdef CONFIG_EXECMEM
+void execmem_init(void);
+#else
+static inline void execmem_init(void) {}
+#endif
+
 #endif /* _LINUX_EXECMEM_ALLOC_H */

diff --git a/mm/execmem.c b/mm/execmem.c
index 638dc2b26a81..f25a5e064886 100644
--- a/mm/execmem.c
+++ b/mm/execmem.c

@@ -5,14 +5,26 @@
 #include <linux/execmem.h>
 #include <linux/moduleloader.h>
 
-static void *execmem_alloc(size_t size)
+static struct execmem_params execmem_params;
+
+static void *execmem_alloc(size_t size, struct execmem_range *range)
 {
-	return module_alloc(size);
+	unsigned long start = range->start;
+	unsigned long end = range->end;
+	unsigned int align = range->alignment;
+	pgprot_t pgprot = range->pgprot;
+
+	return __vmalloc_node_range(size, align, start, end,
+				   GFP_KERNEL, pgprot, VM_FLUSH_RESET_PERMS,
+				   NUMA_NO_NODE, __builtin_return_address(0));
 }
 
 void *execmem_text_alloc(enum execmem_type type, size_t size)
 {
-	return execmem_alloc(size);
+	if (!execmem_params.ranges[type].start)
+		return module_alloc(size);
+
+	return execmem_alloc(size, &execmem_params.ranges[type]);
 }
 
 void execmem_free(void *ptr)

@@ -24,3 +36,51 @@ void execmem_free(void *ptr)
 	WARN_ON(in_interrupt());
 	vfree(ptr);
 }
+
+struct execmem_params * __weak execmem_arch_params(void)
+{
+	return NULL;
+}
+
+static bool execmem_validate_params(struct execmem_params *p)
+{
+	struct execmem_range *r = &p->ranges[EXECMEM_DEFAULT];
+
+	if (!r->alignment || !r->start || !r->end || !pgprot_val(r->pgprot)) {
+		pr_crit("Invalid parameters for execmem allocator, module loading will fail");
+		return false;
+	}
+
+	return true;
+}
+
+static void execmem_init_missing(struct execmem_params *p)
+{
+	struct execmem_range *default_range = &p->ranges[EXECMEM_DEFAULT];
+
+	for (int i = EXECMEM_DEFAULT + 1; i < EXECMEM_TYPE_MAX; i++) {
+		struct execmem_range *r = &p->ranges[i];
+
+		if (!r->start) {
+			r->pgprot = default_range->pgprot;
+			r->alignment = default_range->alignment;
+			r->start = default_range->start;
+			r->end = default_range->end;
+		}
+	}
+}
+
+void __init execmem_init(void)
+{
+	struct execmem_params *p = execmem_arch_params();
+
+	if (!p)
+		return;
+
+	if (!execmem_validate_params(p))
+		return;
+
+	execmem_init_missing(p);
+
+	execmem_params = *p;
+}

diff --git a/mm/mm_init.c b/mm/mm_init.c
index 50f2f34745af..7c002b36da21 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c

@@ -26,6 +26,7 @@
 #include <linux/pgtable.h>
 #include <linux/swap.h>
 #include <linux/cma.h>
+#include <linux/execmem.h>
 #include "internal.h"
 #include "slab.h"
 #include "shuffle.h"

@@ -2797,4 +2798,5 @@ void __init mm_core_init(void)
 	pti_init();
 	kmsan_init_runtime();
 	mm_cache_init();
+	execmem_init();
 }

-- 
2.39.2

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