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mm/execmem, arch: convert simple overrides of module_alloc to execmem

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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_info structure and implement
execmem_arch_setup() 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 a core_initcall() in execmem.

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

Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
This commit is contained in:
Mike Rapoport (IBM) 2024-05-05 19:06:19 +03:00 committed by Luis Chamberlain
parent 12af2b83d0
commit f6bec26c0a
9 changed files with 209 additions and 33 deletions
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19
arch/loongarch/kernel/module.c
View File

@ -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>
#include <asm/unwind.h>
@ -490,10 +491,22 @@ int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
return 0;
}
void *module_alloc(unsigned long size)
static struct execmem_info execmem_info __ro_after_init;
struct execmem_info __init *execmem_arch_setup(void)
{
return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE, __builtin_return_address(0));
execmem_info = (struct execmem_info){
.ranges = {
[EXECMEM_DEFAULT] = {
.start = MODULES_VADDR,
.end = MODULES_END,
.pgprot = PAGE_KERNEL,
.alignment = 1,
},
},
};
return &execmem_info;
}
static void module_init_ftrace_plt(const Elf_Ehdr *hdr,

20
arch/mips/kernel/module.c
View File

@ -20,6 +20,7 @@
#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/jump_label.h>
#include <linux/execmem.h>
#include <asm/jump_label.h>
struct mips_hi16 {
@ -32,11 +33,22 @@ static LIST_HEAD(dbe_list);
static DEFINE_SPINLOCK(dbe_lock);
#ifdef MODULES_VADDR
void *module_alloc(unsigned long size)
static struct execmem_info execmem_info __ro_after_init;
struct execmem_info __init *execmem_arch_setup(void)
{
return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE,
__builtin_return_address(0));
execmem_info = (struct execmem_info){
.ranges = {
[EXECMEM_DEFAULT] = {
.start = MODULES_VADDR,
.end = MODULES_END,
.pgprot = PAGE_KERNEL,
.alignment = 1,
},
},
};
return &execmem_info;
}
#endif

21
arch/nios2/kernel/module.c
View File

@ -18,15 +18,26 @@
#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_info execmem_info __ro_after_init;
struct execmem_info __init *execmem_arch_setup(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));
execmem_info = (struct execmem_info){
.ranges = {
[EXECMEM_DEFAULT] = {
.start = MODULES_VADDR,
.end = MODULES_END,
.pgprot = PAGE_KERNEL_EXEC,
.alignment = 1,
},
},
};
return &execmem_info;
}
int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,

24
arch/parisc/kernel/module.c
View File

@ -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 +174,22 @@ static inline int reassemble_22(int as22)
((as22 & 0x0003ff) << 3));
}
void *module_alloc(unsigned long size)
static struct execmem_info execmem_info __ro_after_init;
struct execmem_info __init *execmem_arch_setup(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_info = (struct execmem_info){
.ranges = {
[EXECMEM_DEFAULT] = {
.start = VMALLOC_START,
.end = VMALLOC_END,
.pgprot = PAGE_KERNEL_RWX,
.alignment = 1,
},
},
};
return &execmem_info;
}
#ifndef CONFIG_64BIT

22
arch/riscv/kernel/module.c
View File

@ -14,6 +14,7 @@
#include <linux/vmalloc.h>
#include <linux/sizes.h>
#include <linux/pgtable.h>
#include <linux/execmem.h>
#include <asm/alternative.h>
#include <asm/sections.h>
@ -906,13 +907,22 @@ 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_info execmem_info __ro_after_init;
struct execmem_info __init *execmem_arch_setup(void)
{
return __vmalloc_node_range(size, 1, MODULES_VADDR,
MODULES_END, GFP_KERNEL,
PAGE_KERNEL, VM_FLUSH_RESET_PERMS,
NUMA_NO_NODE,
__builtin_return_address(0));
execmem_info = (struct execmem_info){
.ranges = {
[EXECMEM_DEFAULT] = {
.start = MODULES_VADDR,
.end = MODULES_END,
.pgprot = PAGE_KERNEL,
.alignment = 1,
},
},
};
return &execmem_info;
}
#endif

20
arch/sparc/kernel/module.c
View File

@ -14,6 +14,7 @@
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/mm.h>
#include <linux/execmem.h>
#include <asm/processor.h>
#include <asm/spitfire.h>
@ -21,11 +22,22 @@
#include "entry.h"
void *module_alloc(unsigned long size)
static struct execmem_info execmem_info __ro_after_init;
struct execmem_info __init *execmem_arch_setup(void)
{
return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE,
__builtin_return_address(0));
execmem_info = (struct execmem_info){
.ranges = {
[EXECMEM_DEFAULT] = {
.start = MODULES_VADDR,
.end = MODULES_END,
.pgprot = PAGE_KERNEL,
.alignment = 1,
},
},
};
return &execmem_info;
}
/* Make generic code ignore STT_REGISTER dummy undefined symbols. */

47
include/linux/execmem.h
View File

@ -33,6 +33,47 @@ enum execmem_type {
EXECMEM_TYPE_MAX,
};
/**
* struct execmem_range - definition of an address space 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_info - architecture parameters for code allocations
* @ranges: array of parameter sets defining architecture specific
* parameters for executable memory allocations. The ranges that are not
* explicitly initialized by an architecture use parameters defined for
* @EXECMEM_DEFAULT.
*/
struct execmem_info {
struct execmem_range ranges[EXECMEM_TYPE_MAX];
};
/**
* execmem_arch_setup - define parameters for allocations of executable memory
*
* A hook for architectures to define parameters for allocations of
* executable memory. These parameters should be filled into the
* @execmem_info structure.
*
* 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_info *execmem_arch_setup(void);
/**
* execmem_alloc - allocate executable memory
* @type: type of the allocation
@ -54,4 +95,10 @@ void *execmem_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 */

67
mm/execmem.c
View File

@ -11,14 +11,30 @@
#include <linux/execmem.h>
#include <linux/moduleloader.h>
static void *__execmem_alloc(size_t size)
static struct execmem_info *execmem_info __ro_after_init;
static void *__execmem_alloc(struct execmem_range *range, size_t size)
{
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_alloc(enum execmem_type type, size_t size)
{
return __execmem_alloc(size);
struct execmem_range *range;
if (!execmem_info)
return module_alloc(size);
range = &execmem_info->ranges[type];
return __execmem_alloc(range, size);
}
void execmem_free(void *ptr)
@ -30,3 +46,48 @@ void execmem_free(void *ptr)
WARN_ON(in_interrupt());
vfree(ptr);
}
static bool execmem_validate(struct execmem_info *info)
{
struct execmem_range *r = &info->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_info *info)
{
struct execmem_range *default_range = &info->ranges[EXECMEM_DEFAULT];
for (int i = EXECMEM_DEFAULT + 1; i < EXECMEM_TYPE_MAX; i++) {
struct execmem_range *r = &info->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;
}
}
}
struct execmem_info * __weak execmem_arch_setup(void)
{
return NULL;
}
void __init execmem_init(void)
{
struct execmem_info *info = execmem_arch_setup();
if (!info || !execmem_validate(info))
return;
execmem_init_missing(info);
execmem_info = info;
}

2
mm/mm_init.c
View File

@ -27,6 +27,7 @@
#include <linux/swap.h>
#include <linux/cma.h>
#include <linux/crash_dump.h>
#include <linux/execmem.h>
#include "internal.h"
#include "slab.h"
#include "shuffle.h"
@ -2793,4 +2794,5 @@ void __init mm_core_init(void)
pti_init();
kmsan_init_runtime();
mm_cache_init();
execmem_init();
}