* Lorenzo Stoakes <lstoakes@xxxxxxxxx> [240627 06:40]:
> Establish a new userland VMA unit testing implementation under
> tools/testing which utilises existing logic providing maple tree support in
> userland utilising the now-shared code previously exclusive to radix tree
> testing.
>
> This provides fundamental VMA operations whose API is defined in mm/vma.h,
> while stubbing out superfluous functionality.
>
> This exists as a proof-of-concept, with the test implementation functional
> and sufficient to allow userland compilation of vma.c, but containing only
> cursory tests to demonstrate basic functionality.
>
> Signed-off-by: Lorenzo Stoakes <lstoakes@xxxxxxxxx>
> ---
> MAINTAINERS | 1 +
> tools/testing/vma/.gitignore | 7 +
> tools/testing/vma/Makefile | 18 +
> tools/testing/vma/errors.txt | 0
> tools/testing/vma/generated/autoconf.h | 2 +
> tools/testing/vma/linux/atomic.h | 19 +
> tools/testing/vma/linux/mmzone.h | 37 ++
> tools/testing/vma/main.c | 161 +++++
> tools/testing/vma/vma.h | 3 +
> tools/testing/vma/vma_internal.h | 843 +++++++++++++++++++++++++
> tools/testing/vma/vma_stub.c | 6 +
> 11 files changed, 1097 insertions(+)
> create mode 100644 tools/testing/vma/.gitignore
> create mode 100644 tools/testing/vma/Makefile
> create mode 100644 tools/testing/vma/errors.txt
> create mode 100644 tools/testing/vma/generated/autoconf.h
> create mode 100644 tools/testing/vma/linux/atomic.h
> create mode 100644 tools/testing/vma/linux/mmzone.h
> create mode 100644 tools/testing/vma/main.c
> create mode 100644 tools/testing/vma/vma.h
> create mode 100644 tools/testing/vma/vma_internal.h
> create mode 100644 tools/testing/vma/vma_stub.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 0847cb5903ab..410062bd8e21 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -23983,6 +23983,7 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
> F: mm/vma.c
> F: mm/vma.h
> F: mm/vma_internal.h
> +F: tools/testing/vma
>
> VMALLOC
> M: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> diff --git a/tools/testing/vma/.gitignore b/tools/testing/vma/.gitignore
> new file mode 100644
> index 000000000000..a8b785063b1c
> --- /dev/null
> +++ b/tools/testing/vma/.gitignore
> @@ -0,0 +1,7 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +generated/bit-length.h
> +generated/map-shift.h
> +idr.c
> +main
> +radix-tree.c
> +vma.c
> diff --git a/tools/testing/vma/Makefile b/tools/testing/vma/Makefile
> new file mode 100644
> index 000000000000..50d2a69ddff8
> --- /dev/null
> +++ b/tools/testing/vma/Makefile
> @@ -0,0 +1,18 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +.PHONY: default
> +
> +default: main
> +
> +include ../shared/shared.mk
> +
> +OFILES = main.o $(SHARED_OFILES) maple-shim.o vma_stub.o
> +TARGETS = main
> +
> +vma.c: ../../../mm/vma.c
> + cp $< $@
> +
> +main: $(OFILES)
This needs some work to automatically run the copy target.
> +
> +clean:
> + $(RM) $(TARGETS) *.o radix-tree.c idr.c generated/map-shift.h generated/bit-length.h
This needs to clean out vma.c to avoid stale testing.
But, none of this is needed.
What we can do instead is add the correct header guards to the
mm/vma_internal.h file, change the tools/testing/vma/vma_internal.h
header guards to be the same (ie: remove TESTING_ from the existing
ones), then we can include vma_internal.h into vma_stub.c prior to
including "../../../mm/vma.c", and we don't need to copy the file.
Essentially use the #ifdef guards to replace the header by ordering the
local header for inclusion prior to the c file.
> diff --git a/tools/testing/vma/errors.txt b/tools/testing/vma/errors.txt
> new file mode 100644
> index 000000000000..e69de29bb2d1
> diff --git a/tools/testing/vma/generated/autoconf.h b/tools/testing/vma/generated/autoconf.h
> new file mode 100644
> index 000000000000..92dc474c349b
> --- /dev/null
> +++ b/tools/testing/vma/generated/autoconf.h
> @@ -0,0 +1,2 @@
> +#include "bit-length.h"
> +#define CONFIG_XARRAY_MULTI 1
> diff --git a/tools/testing/vma/linux/atomic.h b/tools/testing/vma/linux/atomic.h
> new file mode 100644
> index 000000000000..298b0fb7aab2
> --- /dev/null
> +++ b/tools/testing/vma/linux/atomic.h
This should have header guards as well.
> @@ -0,0 +1,19 @@
> +#ifndef atomic_t
> +#define atomic_t int32_t
> +#endif
> +
> +#ifndef atomic_inc
> +#define atomic_inc(x) uatomic_inc(x)
> +#endif
> +
> +#ifndef atomic_read
> +#define atomic_read(x) uatomic_read(x)
> +#endif
> +
> +#ifndef atomic_set
> +#define atomic_set(x, y) do {} while (0)
> +#endif
> +
> +#ifndef U8_MAX
> +#define U8_MAX UCHAR_MAX
> +#endif
> diff --git a/tools/testing/vma/linux/mmzone.h b/tools/testing/vma/linux/mmzone.h
> new file mode 100644
> index 000000000000..71546e15bdd3
> --- /dev/null
> +++ b/tools/testing/vma/linux/mmzone.h
> @@ -0,0 +1,37 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _TOOLS_MMZONE_H
> +#define _TOOLS_MMZONE_H
It might be best to use the same guards here to avoid mmzone.h from
getting pulled in.
> +
> +#include <linux/atomic.h>
> +
> +struct pglist_data *first_online_pgdat(void);
> +struct pglist_data *next_online_pgdat(struct pglist_data *pgdat);
> +
> +#define for_each_online_pgdat(pgdat) \
> + for (pgdat = first_online_pgdat(); \
> + pgdat; \
> + pgdat = next_online_pgdat(pgdat))
> +
> +enum zone_type {
> + __MAX_NR_ZONES
> +};
> +
> +#define MAX_NR_ZONES __MAX_NR_ZONES
> +#define MAX_PAGE_ORDER 10
> +#define MAX_ORDER_NR_PAGES (1 << MAX_PAGE_ORDER)
> +
> +#define pageblock_order MAX_PAGE_ORDER
> +#define pageblock_nr_pages BIT(pageblock_order)
> +#define pageblock_align(pfn) ALIGN((pfn), pageblock_nr_pages)
> +#define pageblock_start_pfn(pfn) ALIGN_DOWN((pfn), pageblock_nr_pages)
> +
> +struct zone {
> + atomic_long_t managed_pages;
> +};
> +
> +typedef struct pglist_data {
> + struct zone node_zones[MAX_NR_ZONES];
> +
> +} pg_data_t;
> +
> +#endif
> diff --git a/tools/testing/vma/main.c b/tools/testing/vma/main.c
> new file mode 100644
> index 000000000000..b29eeb0daf31
> --- /dev/null
> +++ b/tools/testing/vma/main.c
If you employ the use of header guards, we can rename main.c to vma.c
and produce the executable "vma" instead of "main".
> @@ -0,0 +1,161 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +
> +#include <assert.h>
> +#include <stdio.h>
> +#include <stdlib.h>
> +
> +#include "maple-shared.h"
> +#include "vma_internal.h"
> +#include "vma.h"
You can directly include "../../../mm/vma.h" here and remove the vma.h
file you have in this directory.
> +
> +/*
> + * This skeleton implementation doesn't necessarily clean up after itself
> + * very well, so don't check for leaks.
> + */
> +const char *__asan_default_options(void) { return "detect_leaks=0"; }
> +
> +static void test_simple_merge(void)
> +{
> + struct vm_area_struct *vma;
> + unsigned long flags = VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE;
> + struct mm_struct mm = {};
> + struct vm_area_struct vma_left = {
> + .vm_mm = &mm,
> + .vm_start = 0,
> + .vm_end = 0x1000,
> + .vm_pgoff = 0,
> + .vm_flags = flags,
> + };
> + struct vm_area_struct vma_middle = {
> + .vm_mm = &mm,
> + .vm_start = 0x1000,
> + .vm_end = 0x2000,
> + .vm_pgoff = 1,
> + .vm_flags = flags,
> + };
> + struct vm_area_struct vma_right = {
> + .vm_mm = &mm,
> + .vm_start = 0x2000,
> + .vm_end = 0x3000,
> + .vm_pgoff = 2,
> + .vm_flags = flags,
> + };
> + VMA_ITERATOR(vmi, &mm, 0x1000);
> +
> + assert(!vma_link(&mm, &vma_left));
> + assert(!vma_link(&mm, &vma_middle));
> + assert(!vma_link(&mm, &vma_right));
> +
> + vma = vma_merge_new_vma(&vmi, &vma_left, &vma_middle, 0x1000,
> + 0x2000, 1);
> + assert(vma != NULL);
> +
> + assert(vma->vm_start == 0);
> + assert(vma->vm_end == 0x3000);
> + assert(vma->vm_pgoff == 0);
> + assert(vma->vm_flags == flags);
> +}
> +
> +static void test_simple_modify(void)
> +{
> + struct vm_area_struct *vma;
> + unsigned long flags = VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE;
> + struct mm_struct mm = {};
> + struct vm_area_struct init_vma = {
> + .vm_mm = &mm,
> + .vm_start = 0,
> + .vm_end = 0x3000,
> + .vm_flags = flags,
> + };
> + VMA_ITERATOR(vmi, &mm, 0x1000);
> +
> + assert(!vma_link(&mm, &init_vma));
> +
> + /*
> + * The flags will not be changed, the vma_modify_flags() function
> + * performs the merge/split only.
> + */
> + vma = vma_modify_flags(&vmi, NULL, &init_vma,
> + 0x1000, 0x2000, VM_READ | VM_MAYREAD);
> + assert(vma != NULL);
> + /* We modify the provided VMA, and on split allocate new VMAs. */
> + assert(vma == &init_vma);
> +
> + assert(vma->vm_start == 0x1000);
> + assert(vma->vm_end == 0x2000);
> + assert(vma->vm_pgoff == 1);
> +
> + /*
> + * Now walk through the three split VMAs and make sure they are as
> + * expected.
> + */
> +
> + vma_iter_set(&vmi, 0);
> + vma = vma_iter_load(&vmi);
> +
> + assert(vma->vm_start == 0);
> + assert(vma->vm_end == 0x1000);
> + assert(vma->vm_pgoff == 0);
> +
> + vma = vma_next(&vmi);
> +
> + assert(vma->vm_start == 0x1000);
> + assert(vma->vm_end == 0x2000);
> + assert(vma->vm_pgoff == 1);
> +
> + vma = vma_next(&vmi);
> +
> + assert(vma->vm_start == 0x2000);
> + assert(vma->vm_end == 0x3000);
> + assert(vma->vm_pgoff == 2);
> +}
> +
> +static void test_simple_expand(void)
> +{
> + unsigned long flags = VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE;
> + struct mm_struct mm = {};
> + struct vm_area_struct vma = {
> + .vm_mm = &mm,
> + .vm_start = 0,
> + .vm_end = 0x1000,
> + .vm_flags = flags,
> + };
> + VMA_ITERATOR(vmi, &mm, 0);
> +
> + assert(!vma_expand(&vmi, &vma, 0, 0x3000, 0, NULL));
> +
> + assert(vma.vm_start == 0);
> + assert(vma.vm_end == 0x3000);
> + assert(vma.vm_pgoff == 0);
> +}
> +
> +static void test_simple_shrink(void)
> +{
> + unsigned long flags = VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE;
> + struct mm_struct mm = {};
> + struct vm_area_struct vma = {
> + .vm_mm = &mm,
> + .vm_start = 0,
> + .vm_end = 0x3000,
> + .vm_flags = flags,
> + };
> + VMA_ITERATOR(vmi, &mm, 0);
> +
> + assert(!vma_shrink(&vmi, &vma, 0, 0x1000, 0));
> +
> + assert(vma.vm_start == 0);
> + assert(vma.vm_end == 0x1000);
> + assert(vma.vm_pgoff == 0);
> +}
> +
> +int main(void)
> +{
> + maple_tree_init();
> +
> + test_simple_merge();
> + test_simple_modify();
> + test_simple_expand();
> + test_simple_shrink();
> +
> + return EXIT_SUCCESS;
> +}
It would be nice to have some output stating the number of tests
passed/failed.
> diff --git a/tools/testing/vma/vma.h b/tools/testing/vma/vma.h
> new file mode 100644
> index 000000000000..87a6cb222b63
> --- /dev/null
> +++ b/tools/testing/vma/vma.h
> @@ -0,0 +1,3 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +
> +#include "../../../mm/vma.h"
I'd rather just drop this file and have this line in main.c (or vma.c if
you decide to rename it).
> diff --git a/tools/testing/vma/vma_internal.h b/tools/testing/vma/vma_internal.h
> new file mode 100644
> index 000000000000..8be8cbecf3b8
> --- /dev/null
> +++ b/tools/testing/vma/vma_internal.h
> @@ -0,0 +1,843 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +
> +#ifndef __TESTING_VMA_VMA_INTERNAL_H
> +#define __TESTING_VMA_VMA_INTERNAL_H
> +
> +#define __private
> +#define __bitwise
> +#define __randomize_layout
> +
> +#define CONFIG_MMU
> +#define CONFIG_PER_VMA_LOCK
> +
> +#include <stdlib.h>
> +
> +#include <linux/list.h>
> +#include <linux/maple_tree.h>
> +#include <linux/mm.h>
> +#include <linux/rbtree.h>
> +#include <linux/rwsem.h>
> +
> +#define VM_WARN_ON(_expr)
> +#define VM_WARN_ON_ONCE(_expr)
> +#define VM_BUG_ON(_expr)
> +#define VM_BUG_ON_VMA(_expr, _vma) ((void)(_expr))
> +
> +#define VM_NONE 0x00000000
> +#define VM_READ 0x00000001
> +#define VM_WRITE 0x00000002
> +#define VM_EXEC 0x00000004
> +#define VM_SHARED 0x00000008
> +#define VM_MAYREAD 0x00000010
> +#define VM_MAYWRITE 0x00000020
> +#define VM_GROWSDOWN 0x00000100
> +#define VM_PFNMAP 0x00000400
> +#define VM_LOCKED 0x00002000
> +#define VM_IO 0x00004000
> +#define VM_DONTEXPAND 0x00040000
> +#define VM_ACCOUNT 0x00100000
> +#define VM_MIXEDMAP 0x10000000
> +#define VM_STACK VM_GROWSDOWN
> +#define VM_SHADOW_STACK VM_NONE
> +#define VM_SOFTDIRTY 0
> +
> +#define VM_ACCESS_FLAGS (VM_READ | VM_WRITE | VM_EXEC)
> +#define VM_SPECIAL (VM_IO | VM_DONTEXPAND | VM_PFNMAP | VM_MIXEDMAP)
> +
> +#define FIRST_USER_ADDRESS 0UL
> +#define USER_PGTABLES_CEILING 0UL
> +
> +#define vma_policy(vma) NULL
> +
> +#define down_write_nest_lock(sem, nest_lock)
> +
> +#define pgprot_val(x) ((x).pgprot)
> +#define __pgprot(x) ((pgprot_t) { (x) } )
> +
> +#define for_each_vma(__vmi, __vma) \
> + while (((__vma) = vma_next(&(__vmi))) != NULL)
> +
> +/* The MM code likes to work with exclusive end addresses */
> +#define for_each_vma_range(__vmi, __vma, __end) \
> + while (((__vma) = vma_find(&(__vmi), (__end))) != NULL)
> +
> +#define offset_in_page(p) ((unsigned long)(p) & ~PAGE_MASK)
> +
> +#define PHYS_PFN(x) ((unsigned long)((x) >> PAGE_SHIFT))
> +
> +#define test_and_set_bit(nr, addr) __test_and_set_bit(nr, addr)
> +#define test_and_clear_bit(nr, addr) __test_and_clear_bit(nr, addr)
> +
> +#define TASK_SIZE ((1ul << 47)-PAGE_SIZE)
> +
> +#define AS_MM_ALL_LOCKS 2
> +
> +#define current NULL
> +
> +/* We hardcode this for now. */
> +#define sysctl_max_map_count 0x1000000UL
> +
> +#define pgoff_t unsigned long
> +typedef unsigned long pgprotval_t;
> +typedef struct pgprot { pgprotval_t pgprot; } pgprot_t;
> +typedef unsigned long vm_flags_t;
> +typedef __bitwise unsigned int vm_fault_t;
> +
> +typedef struct refcount_struct {
> + atomic_t refs;
> +} refcount_t;
> +
> +struct kref {
> + refcount_t refcount;
> +};
> +
> +struct anon_vma {
> + struct anon_vma *root;
> + struct rb_root_cached rb_root;
> +};
> +
> +struct anon_vma_chain {
> + struct anon_vma *anon_vma;
> + struct list_head same_vma;
> +};
> +
> +struct anon_vma_name {
> + struct kref kref;
> + /* The name needs to be at the end because it is dynamically sized. */
> + char name[];
> +};
> +
> +struct vma_iterator {
> + struct ma_state mas;
> +};
> +
> +#define VMA_ITERATOR(name, __mm, __addr) \
> + struct vma_iterator name = { \
> + .mas = { \
> + .tree = &(__mm)->mm_mt, \
> + .index = __addr, \
> + .node = NULL, \
> + .status = ma_start, \
> + }, \
> + }
> +
> +struct address_space {
> + struct rb_root_cached i_mmap;
> + unsigned long flags;
> + atomic_t i_mmap_writable;
> +};
> +
> +struct vm_userfaultfd_ctx {};
> +struct mempolicy {};
> +struct mmu_gather {};
> +struct mutex {};
> +#define DEFINE_MUTEX(mutexname) \
> + struct mutex mutexname = {}
> +
> +struct mm_struct {
> + struct maple_tree mm_mt;
> + int map_count; /* number of VMAs */
> + unsigned long total_vm; /* Total pages mapped */
> + unsigned long locked_vm; /* Pages that have PG_mlocked set */
> + unsigned long data_vm; /* VM_WRITE & ~VM_SHARED & ~VM_STACK */
> + unsigned long exec_vm; /* VM_EXEC & ~VM_WRITE & ~VM_STACK */
> + unsigned long stack_vm; /* VM_STACK */
> +};
> +
> +struct vma_lock {
> + struct rw_semaphore lock;
> +};
> +
> +
> +struct file {
> + struct address_space *f_mapping;
> +};
> +
> +struct vm_area_struct {
> + /* The first cache line has the info for VMA tree walking. */
> +
> + union {
> + struct {
> + /* VMA covers [vm_start; vm_end) addresses within mm */
> + unsigned long vm_start;
> + unsigned long vm_end;
> + };
> +#ifdef CONFIG_PER_VMA_LOCK
> + struct rcu_head vm_rcu; /* Used for deferred freeing. */
> +#endif
> + };
> +
> + struct mm_struct *vm_mm; /* The address space we belong to. */
> + pgprot_t vm_page_prot; /* Access permissions of this VMA. */
> +
> + /*
> + * Flags, see mm.h.
> + * To modify use vm_flags_{init|reset|set|clear|mod} functions.
> + */
> + union {
> + const vm_flags_t vm_flags;
> + vm_flags_t __private __vm_flags;
> + };
> +
> +#ifdef CONFIG_PER_VMA_LOCK
> + /* Flag to indicate areas detached from the mm->mm_mt tree */
> + bool detached;
> +
> + /*
> + * Can only be written (using WRITE_ONCE()) while holding both:
> + * - mmap_lock (in write mode)
> + * - vm_lock->lock (in write mode)
> + * Can be read reliably while holding one of:
> + * - mmap_lock (in read or write mode)
> + * - vm_lock->lock (in read or write mode)
> + * Can be read unreliably (using READ_ONCE()) for pessimistic bailout
> + * while holding nothing (except RCU to keep the VMA struct allocated).
> + *
> + * This sequence counter is explicitly allowed to overflow; sequence
> + * counter reuse can only lead to occasional unnecessary use of the
> + * slowpath.
> + */
> + int vm_lock_seq;
> + struct vma_lock *vm_lock;
> +#endif
> +
> + /*
> + * For areas with an address space and backing store,
> + * linkage into the address_space->i_mmap interval tree.
> + *
> + */
> + struct {
> + struct rb_node rb;
> + unsigned long rb_subtree_last;
> + } shared;
> +
> + /*
> + * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma
> + * list, after a COW of one of the file pages. A MAP_SHARED vma
> + * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack
> + * or brk vma (with NULL file) can only be in an anon_vma list.
> + */
> + struct list_head anon_vma_chain; /* Serialized by mmap_lock &
> + * page_table_lock */
> + struct anon_vma *anon_vma; /* Serialized by page_table_lock */
> +
> + /* Function pointers to deal with this struct. */
> + const struct vm_operations_struct *vm_ops;
> +
> + /* Information about our backing store: */
> + unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE
> + units */
> + struct file * vm_file; /* File we map to (can be NULL). */
> + void * vm_private_data; /* was vm_pte (shared mem) */
> +
> +#ifdef CONFIG_ANON_VMA_NAME
> + /*
> + * For private and shared anonymous mappings, a pointer to a null
> + * terminated string containing the name given to the vma, or NULL if
> + * unnamed. Serialized by mmap_lock. Use anon_vma_name to access.
> + */
> + struct anon_vma_name *anon_name;
> +#endif
> +#ifdef CONFIG_SWAP
> + atomic_long_t swap_readahead_info;
> +#endif
> +#ifndef CONFIG_MMU
> + struct vm_region *vm_region; /* NOMMU mapping region */
> +#endif
> +#ifdef CONFIG_NUMA
> + struct mempolicy *vm_policy; /* NUMA policy for the VMA */
> +#endif
> +#ifdef CONFIG_NUMA_BALANCING
> + struct vma_numab_state *numab_state; /* NUMA Balancing state */
> +#endif
> + struct vm_userfaultfd_ctx vm_userfaultfd_ctx;
> +} __randomize_layout;
> +
> +struct vm_fault {};
> +
> +struct vm_operations_struct {
> + void (*open)(struct vm_area_struct * area);
> + /**
> + * @close: Called when the VMA is being removed from the MM.
> + * Context: User context. May sleep. Caller holds mmap_lock.
> + */
> + void (*close)(struct vm_area_struct * area);
> + /* Called any time before splitting to check if it's allowed */
> + int (*may_split)(struct vm_area_struct *area, unsigned long addr);
> + int (*mremap)(struct vm_area_struct *area);
> + /*
> + * Called by mprotect() to make driver-specific permission
> + * checks before mprotect() is finalised. The VMA must not
> + * be modified. Returns 0 if mprotect() can proceed.
> + */
> + int (*mprotect)(struct vm_area_struct *vma, unsigned long start,
> + unsigned long end, unsigned long newflags);
> + vm_fault_t (*fault)(struct vm_fault *vmf);
> + vm_fault_t (*huge_fault)(struct vm_fault *vmf, unsigned int order);
> + vm_fault_t (*map_pages)(struct vm_fault *vmf,
> + pgoff_t start_pgoff, pgoff_t end_pgoff);
> + unsigned long (*pagesize)(struct vm_area_struct * area);
> +
> + /* notification that a previously read-only page is about to become
> + * writable, if an error is returned it will cause a SIGBUS */
> + vm_fault_t (*page_mkwrite)(struct vm_fault *vmf);
> +
> + /* same as page_mkwrite when using VM_PFNMAP|VM_MIXEDMAP */
> + vm_fault_t (*pfn_mkwrite)(struct vm_fault *vmf);
> +
> + /* called by access_process_vm when get_user_pages() fails, typically
> + * for use by special VMAs. See also generic_access_phys() for a generic
> + * implementation useful for any iomem mapping.
> + */
> + int (*access)(struct vm_area_struct *vma, unsigned long addr,
> + void *buf, int len, int write);
> +
> + /* Called by the /proc/PID/maps code to ask the vma whether it
> + * has a special name. Returning non-NULL will also cause this
> + * vma to be dumped unconditionally. */
> + const char *(*name)(struct vm_area_struct *vma);
> +
> +#ifdef CONFIG_NUMA
> + /*
> + * set_policy() op must add a reference to any non-NULL @new mempolicy
> + * to hold the policy upon return. Caller should pass NULL @new to
> + * remove a policy and fall back to surrounding context--i.e. do not
> + * install a MPOL_DEFAULT policy, nor the task or system default
> + * mempolicy.
> + */
> + int (*set_policy)(struct vm_area_struct *vma, struct mempolicy *new);
> +
> + /*
> + * get_policy() op must add reference [mpol_get()] to any policy at
> + * (vma,addr) marked as MPOL_SHARED. The shared policy infrastructure
> + * in mm/mempolicy.c will do this automatically.
> + * get_policy() must NOT add a ref if the policy at (vma,addr) is not
> + * marked as MPOL_SHARED. vma policies are protected by the mmap_lock.
> + * If no [shared/vma] mempolicy exists at the addr, get_policy() op
> + * must return NULL--i.e., do not "fallback" to task or system default
> + * policy.
> + */
> + struct mempolicy *(*get_policy)(struct vm_area_struct *vma,
> + unsigned long addr, pgoff_t *ilx);
> +#endif
> + /*
> + * Called by vm_normal_page() for special PTEs to find the
> + * page for @addr. This is useful if the default behavior
> + * (using pte_page()) would not find the correct page.
> + */
> + struct page *(*find_special_page)(struct vm_area_struct *vma,
> + unsigned long addr);
> +};
> +
> +static inline void vma_iter_invalidate(struct vma_iterator *vmi)
> +{
> + mas_pause(&vmi->mas);
> +}
> +
> +static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
> +{
> + return __pgprot(pgprot_val(oldprot) | pgprot_val(newprot));
> +}
> +
> +static inline pgprot_t vm_get_page_prot(unsigned long vm_flags)
> +{
> + return __pgprot(vm_flags);
> +}
> +
> +static inline bool is_shared_maywrite(vm_flags_t vm_flags)
> +{
> + return (vm_flags & (VM_SHARED | VM_MAYWRITE)) ==
> + (VM_SHARED | VM_MAYWRITE);
> +}
> +
> +static inline bool vma_is_shared_maywrite(struct vm_area_struct *vma)
> +{
> + return is_shared_maywrite(vma->vm_flags);
> +}
> +
> +static inline struct vm_area_struct *vma_next(struct vma_iterator *vmi)
> +{
> + /*
> + * Uses mas_find() to get the first VMA when the iterator starts.
> + * Calling mas_next() could skip the first entry.
> + */
> + return mas_find(&vmi->mas, ULONG_MAX);
> +}
> +
> +static inline bool vma_lock_alloc(struct vm_area_struct *vma)
> +{
> + vma->vm_lock = calloc(1, sizeof(struct vma_lock));
> +
> + if (!vma->vm_lock)
> + return false;
> +
> + init_rwsem(&vma->vm_lock->lock);
> + vma->vm_lock_seq = -1;
> +
> + return true;
> +}
> +
> +static inline struct vm_area_struct *vm_area_dup(struct vm_area_struct *orig)
> +{
> + struct vm_area_struct *new = calloc(1, sizeof(struct vm_area_struct));
> +
> + if (!new)
> + return NULL;
> +
> + memcpy(new, orig, sizeof(*new));
> + if (!vma_lock_alloc(new)) {
> + free(new);
> + return NULL;
> + }
> + INIT_LIST_HEAD(&new->anon_vma_chain);
> +
> + return new;
> +}
> +
> +/*
> + * These are defined in vma.h, but sadly vm_stat_account() is referenced by
> + * kernel/fork.c, so we have to these broadly available there, and temporarily
> + * define them here to resolve the dependency cycle.
> + */
> +
> +#define is_exec_mapping(flags) \
> + ((flags & (VM_EXEC | VM_WRITE | VM_STACK)) == VM_EXEC)
> +
> +#define is_stack_mapping(flags) \
> + (((flags & VM_STACK) == VM_STACK) || (flags & VM_SHADOW_STACK))
> +
> +#define is_data_mapping(flags) \
> + ((flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE)
> +
> +static inline void vm_stat_account(struct mm_struct *mm, vm_flags_t flags,
> + long npages)
> +{
> + WRITE_ONCE(mm->total_vm, READ_ONCE(mm->total_vm)+npages);
> +
> + if (is_exec_mapping(flags))
> + mm->exec_vm += npages;
> + else if (is_stack_mapping(flags))
> + mm->stack_vm += npages;
> + else if (is_data_mapping(flags))
> + mm->data_vm += npages;
> +}
> +
> +#undef is_exec_mapping
> +#undef is_stack_mapping
> +#undef is_data_mapping
> +
> +/* Currently stubbed but we may later wish to un-stub. */
> +static inline void vm_acct_memory(long pages);
> +static inline void vm_unacct_memory(long pages)
> +{
> + vm_acct_memory(-pages);
> +}
> +
> +static inline void mapping_allow_writable(struct address_space *mapping)
> +{
> + atomic_inc(&mapping->i_mmap_writable);
> +}
> +
> +static inline void vma_set_range(struct vm_area_struct *vma,
> + unsigned long start, unsigned long end,
> + pgoff_t pgoff)
> +{
> + vma->vm_start = start;
> + vma->vm_end = end;
> + vma->vm_pgoff = pgoff;
> +}
> +
> +static inline void vma_assert_write_locked(struct vm_area_struct *);
> +static inline void vma_mark_detached(struct vm_area_struct *vma, bool detached)
> +{
> + /* When detaching vma should be write-locked */
> + if (detached)
> + vma_assert_write_locked(vma);
> + vma->detached = detached;
> +}
> +
> +static inline
> +struct vm_area_struct *vma_find(struct vma_iterator *vmi, unsigned long max)
> +{
> + return mas_find(&vmi->mas, max - 1);
> +}
> +
> +static inline
> +struct vm_area_struct *vma_iter_prev_range(struct vma_iterator *vmi)
> +{
> + return mas_prev_range(&vmi->mas, 0);
> +}
> +
> +static inline int vma_iter_clear_gfp(struct vma_iterator *vmi,
> + unsigned long start, unsigned long end, gfp_t gfp)
> +{
> + __mas_set_range(&vmi->mas, start, end - 1);
> + mas_store_gfp(&vmi->mas, NULL, gfp);
> + if (unlikely(mas_is_err(&vmi->mas)))
> + return -ENOMEM;
> +
> + return 0;
> +}
> +
> +static inline void mmap_assert_locked(struct mm_struct *);
> +static inline struct vm_area_struct *find_vma_intersection(struct mm_struct *mm,
> + unsigned long start_addr,
> + unsigned long end_addr)
> +{
> + unsigned long index = start_addr;
> +
> + mmap_assert_locked(mm);
> + return mt_find(&mm->mm_mt, &index, end_addr - 1);
> +}
> +
> +static inline
> +struct vm_area_struct *vma_lookup(struct mm_struct *mm, unsigned long addr)
> +{
> + return mtree_load(&mm->mm_mt, addr);
> +}
> +
> +static inline struct vm_area_struct *vma_prev(struct vma_iterator *vmi)
> +{
> + return mas_prev(&vmi->mas, 0);
> +}
> +
> +static inline void vma_iter_set(struct vma_iterator *vmi, unsigned long addr)
> +{
> + mas_set(&vmi->mas, addr);
> +}
> +
> +static inline bool vma_is_anonymous(struct vm_area_struct *vma)
> +{
> + return !vma->vm_ops;
> +}
> +
> +/* Defined in vma.h, so temporarily define here to avoid circular dependency. */
> +#define vma_iter_load(vmi) \
> + mas_walk(&(vmi)->mas)
> +
> +static inline struct vm_area_struct *
> +find_vma_prev(struct mm_struct *mm, unsigned long addr,
> + struct vm_area_struct **pprev)
> +{
> + struct vm_area_struct *vma;
> + VMA_ITERATOR(vmi, mm, addr);
> +
> + vma = vma_iter_load(&vmi);
> + *pprev = vma_prev(&vmi);
> + if (!vma)
> + vma = vma_next(&vmi);
> + return vma;
> +}
> +
> +#undef vma_iter_load
> +
> +static inline void vma_iter_init(struct vma_iterator *vmi,
> + struct mm_struct *mm, unsigned long addr)
> +{
> + mas_init(&vmi->mas, &mm->mm_mt, addr);
> +}
> +
> +/* Stubbed functions. */
> +
> +static inline struct anon_vma_name *anon_vma_name(struct vm_area_struct *vma)
> +{
> + return NULL;
> +}
> +
> +static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
> + struct vm_userfaultfd_ctx vm_ctx)
> +{
> + return true;
> +}
> +
> +static inline bool anon_vma_name_eq(struct anon_vma_name *anon_name1,
> + struct anon_vma_name *anon_name2)
> +{
> + return true;
> +}
> +
> +static inline void might_sleep(void)
> +{
> +}
> +
> +static inline unsigned long vma_pages(struct vm_area_struct *vma)
> +{
> + return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
> +}
> +
> +static inline void fput(struct file *)
> +{
> +}
> +
> +static inline void mpol_put(struct mempolicy *)
> +{
> +}
> +
> +static inline void __vm_area_free(struct vm_area_struct *)
> +{
> +}
> +
> +static inline void vm_area_free(struct vm_area_struct *)
> +{
> +}
> +
> +static inline void lru_add_drain(void)
> +{
> +}
> +
> +static inline void tlb_gather_mmu(struct mmu_gather *, struct mm_struct *)
> +{
> +}
> +
> +static inline void update_hiwater_rss(struct mm_struct *)
> +{
> +}
> +
> +static inline void update_hiwater_vm(struct mm_struct *)
> +{
> +}
> +
> +static inline void unmap_vmas(struct mmu_gather *tlb, struct ma_state *mas,
> + struct vm_area_struct *vma, unsigned long start_addr,
> + unsigned long end_addr, unsigned long tree_end,
> + bool mm_wr_locked)
> +{
> + (void)tlb;
> + (void)mas;
> + (void)vma;
> + (void)start_addr;
> + (void)end_addr;
> + (void)tree_end;
> + (void)mm_wr_locked;
> +}
> +
> +static inline void free_pgtables(struct mmu_gather *tlb, struct ma_state *mas,
> + struct vm_area_struct *vma, unsigned long floor,
> + unsigned long ceiling, bool mm_wr_locked)
> +{
> + (void)tlb;
> + (void)mas;
> + (void)vma;
> + (void)floor;
> + (void)ceiling;
> + (void)mm_wr_locked;
> +}
> +
> +static inline void mapping_unmap_writable(struct address_space *)
> +{
> +}
> +
> +static inline void flush_dcache_mmap_lock(struct address_space *)
> +{
> +}
> +
> +static inline void tlb_finish_mmu(struct mmu_gather *)
> +{
> +}
> +
> +static inline void get_file(struct file *)
> +{
> +}
> +
> +static inline int vma_dup_policy(struct vm_area_struct *, struct vm_area_struct *)
> +{
> + return 0;
> +}
> +
> +static inline int anon_vma_clone(struct vm_area_struct *, struct vm_area_struct *)
> +{
> + return 0;
> +}
> +
> +static inline void vma_start_write(struct vm_area_struct *)
> +{
> +}
> +
> +static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
> + unsigned long start,
> + unsigned long end,
> + long adjust_next)
> +{
> + (void)vma;
> + (void)start;
> + (void)end;
> + (void)adjust_next;
> +}
> +
> +static inline void vma_iter_free(struct vma_iterator *)
> +{
> +}
> +
> +static inline void vm_acct_memory(long pages)
> +{
> +}
> +
> +static inline void vma_interval_tree_insert(struct vm_area_struct *,
> + struct rb_root_cached *)
> +{
> +}
> +
> +static inline void vma_interval_tree_remove(struct vm_area_struct *,
> + struct rb_root_cached *)
> +{
> +}
> +
> +static inline void flush_dcache_mmap_unlock(struct address_space *)
> +{
> +}
> +
> +static inline void anon_vma_interval_tree_insert(struct anon_vma_chain*,
> + struct rb_root_cached *)
> +{
> +}
> +
> +static inline void anon_vma_interval_tree_remove(struct anon_vma_chain*,
> + struct rb_root_cached *)
> +{
> +}
> +
> +static inline void uprobe_mmap(struct vm_area_struct *)
> +{
> +}
> +
> +static inline void uprobe_munmap(struct vm_area_struct *vma,
> + unsigned long start, unsigned long end)
> +{
> + (void)vma;
> + (void)start;
> + (void)end;
> +}
> +
> +static inline void i_mmap_lock_write(struct address_space *)
> +{
> +}
> +
> +static inline void anon_vma_lock_write(struct anon_vma *)
> +{
> +}
> +
> +static inline void vma_assert_write_locked(struct vm_area_struct *)
> +{
> +}
> +
> +static inline void unlink_anon_vmas(struct vm_area_struct *)
> +{
> +}
> +
> +static inline void anon_vma_unlock_write(struct anon_vma *)
> +{
> +}
> +
> +static inline void i_mmap_unlock_write(struct address_space *)
> +{
> +}
> +
> +static inline void anon_vma_merge(struct vm_area_struct *,
> + struct vm_area_struct *)
> +{
> +}
> +
> +static inline int userfaultfd_unmap_prep(struct vm_area_struct *vma,
> + unsigned long start,
> + unsigned long end,
> + struct list_head *unmaps)
> +{
> + (void)vma;
> + (void)start;
> + (void)end;
> + (void)unmaps;
> +
> + return 0;
> +}
> +
> +static inline void mmap_write_downgrade(struct mm_struct *)
> +{
> +}
> +
> +static inline void mmap_read_unlock(struct mm_struct *)
> +{
> +}
> +
> +static inline void mmap_write_unlock(struct mm_struct *)
> +{
> +}
> +
> +static inline bool can_modify_mm(struct mm_struct *mm,
> + unsigned long start,
> + unsigned long end)
> +{
> + (void)mm;
> + (void)start;
> + (void)end;
> +
> + return true;
> +}
> +
> +static inline void arch_unmap(struct mm_struct *mm,
> + unsigned long start,
> + unsigned long end)
> +{
> + (void)mm;
> + (void)start;
> + (void)end;
> +}
> +
> +static inline void mmap_assert_locked(struct mm_struct *)
> +{
> +}
> +
> +static inline bool mpol_equal(struct mempolicy *, struct mempolicy *)
> +{
> + return true;
> +}
> +
> +static inline void khugepaged_enter_vma(struct vm_area_struct *vma,
> + unsigned long vm_flags)
> +{
> + (void)vma;
> + (void)vm_flags;
> +}
> +
> +static inline bool mapping_can_writeback(struct address_space *)
> +{
> + return true;
> +}
> +
> +static inline bool is_vm_hugetlb_page(struct vm_area_struct *)
> +{
> + return false;
> +}
> +
> +static inline bool vma_soft_dirty_enabled(struct vm_area_struct *)
> +{
> + return false;
> +}
> +
> +static inline bool userfaultfd_wp(struct vm_area_struct *)
> +{
> + return false;
> +}
> +
> +static inline void mmap_assert_write_locked(struct mm_struct *)
> +{
> +}
> +
> +static inline void mutex_lock(struct mutex *)
> +{
> +}
> +
> +static inline void mutex_unlock(struct mutex *)
> +{
> +}
> +
> +static inline bool mutex_is_locked(struct mutex *)
> +{
> + return true;
> +}
> +
> +static inline bool signal_pending(void *)
> +{
> + return false;
> +}
> +
> +#endif /* __TESTING_VMA_VMA_INTERNAL_H */
> diff --git a/tools/testing/vma/vma_stub.c b/tools/testing/vma/vma_stub.c
> new file mode 100644
> index 000000000000..d081122ce951
> --- /dev/null
> +++ b/tools/testing/vma/vma_stub.c
> @@ -0,0 +1,6 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +
> +#include "maple-shared.h"
> +
> +/* Imported from mm/vma.c by the Makefile. */
> +#include "vma.c"
> --
> 2.45.1
>
