This syscall can be used to watch the process's memory and perform atomic operations which aren't possible through procfs. Two operations have been implemented. MEMWATCH_SD_GET is used to get the soft dirty pages. MEMWATCH_SD_CLEAR clears the soft dirty bit from dirty pages. MEMWATCH_SD_IGNORE_VMA can be specified to ignore VMA dirty flags. These operations can be used collectively in one operation as well.

NAME process_memwatch - get process's memory information

SYNOPSIS #include <linux/memwatch.h> /* Definition of MEMWATCH_* constants */

long process_memwatch(int pidfd, unsigned long start, int len, unsigned int flags, void *vec, int vec_len);

Note: Glibc does not provide a wrapper for this system call; call it using syscall(2).

DESCRIPTION process_memwatch() system call is used to get information about the memory of the process.

Arguments pidfd specifies the pidfd of process whose memory needs to be watched. The calling process must have PTRACE_MODE_ATTACH_FS‐ CREDS capabilities over the process whose pidfd has been specified. It can be zero which means that the process wants to watch its own memory. The operation is determined by flags. The start argument must be a multiple of the system page size. The len argument need not be a multiple of the page size, but since the information is returned for the whole pages, len is effectively rounded up to the next multi‐ ple of the page size.

vec is an output array in which the offsets of the pages are returned. Offset is calculated from start address. User lets the kernel know about the size of the vec by passing size in vec_len. The system call returns when the whole range has been searched or vec is completely filled. The whole range isn't cleared if vec fills up completely.

Operations The flags argument specifies the operation to be performed. The MEMWATCH_SD_GET and MEMWATCH_SD_CLEAR operations can be used separately or together to perform MEMWATCH_SD_GET and MEMWATCH_SD_CLEAR atomically as one operation.

MEMWATCH_SD_GET Get the page offsets which are soft dirty.

MEMWATCH_SD_CLEAR Clear the pages which are soft dirty.

MEMWATCH_SD_NO_REUSED_REGIONS This optional flag can be specified in combination with other flags. VM_SOFTDIRTY is ignored for the VMAs for performance reasons. This flag shows only those pages dirty which have been written by the user ex‐ plicitly. All new allocations are not be returned as dirty.

RETURN VALUE The 0 or positive value is returned on success. Positive value when returned shows the number of dirty pages filled in vec. In the event of an error (and assuming that process_memwatch() was invoked via syscall(2)), all opera‐ tions return -1 and set errno to indicate the error.

ERRORS EINVAL invalid arguments.

ESRCH Cannot access the process.

EIO I/O error.

This is based on a patch from Gabriel Krisman Bertazi.

Signed-off-by: Muhammad Usama Anjum usama.anjum@collabora.com --- include/uapi/linux/memwatch.h | 12 ++ mm/Makefile | 2 +- mm/memwatch.c | 285 ++++++++++++++++++++++++++++++++++ 3 files changed, 298 insertions(+), 1 deletion(-) create mode 100644 include/uapi/linux/memwatch.h create mode 100644 mm/memwatch.c

diff --git a/include/uapi/linux/memwatch.h b/include/uapi/linux/memwatch.h new file mode 100644 index 000000000000..7e86ffdc10f5 --- /dev/null +++ b/include/uapi/linux/memwatch.h @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ + +#ifndef _MEMWATCH_H +#define _MEMWATCH_H + +/* memwatch operations */ +#define MEMWATCH_SD_GET 0x1 +#define MEMWATCH_SD_CLEAR 0x2 +#define MEMWATCH_SD_NO_REUSED_REGIONS 0x4 + +#endif + diff --git a/mm/Makefile b/mm/Makefile index 8083fa85a348..aa72e4ced1f3 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -37,7 +37,7 @@ CFLAGS_init-mm.o += $(call cc-disable-warning, override-init) CFLAGS_init-mm.o += $(call cc-disable-warning, initializer-overrides)

mmu-y := nommu.o -mmu-$(CONFIG_MMU) := highmem.o memory.o mincore.o \ +mmu-$(CONFIG_MMU) := highmem.o memory.o memwatch.o mincore.o \ mlock.o mmap.o mmu_gather.o mprotect.o mremap.o \ msync.o page_vma_mapped.o pagewalk.o \ pgtable-generic.o rmap.o vmalloc.o diff --git a/mm/memwatch.c b/mm/memwatch.c new file mode 100644 index 000000000000..9be09bc431d2 --- /dev/null +++ b/mm/memwatch.c @@ -0,0 +1,285 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2020 Collabora Ltd. + */ +#include <linux/pagewalk.h> +#include <linux/vmalloc.h> +#include <linux/syscalls.h> +#include <asm/tlb.h> +#include <asm/tlbflush.h> +#include <linux/sched/mm.h> +#include <linux/mm_inline.h> +#include <uapi/linux/memwatch.h> +#include <uapi/asm-generic/errno-base.h> +#include <linux/compat.h> +#include <linux/minmax.h> + +#ifdef CONFIG_MEM_SOFT_DIRTY +#define MEMWATCH_SD_OPS_MASK (MEMWATCH_SD_GET | MEMWATCH_SD_CLEAR | \ + MEMWATCH_SD_NO_REUSED_REGIONS) + +struct memwatch_sd_private { + unsigned long start; + unsigned int flags; + unsigned int index; + unsigned int vec_len; + unsigned long *vec; +}; + +static int memwatch_pmd_entry(pmd_t *pmd, unsigned long addr, + unsigned long end, struct mm_walk *walk) +{ + struct memwatch_sd_private *p = walk->private; + struct vm_area_struct *vma = walk->vma; + unsigned long start = addr; + spinlock_t *ptl; + pte_t *pte; + int dirty; + bool dirty_vma = (p->flags & MEMWATCH_SD_NO_REUSED_REGIONS) ? 0 : + (vma->vm_flags & VM_SOFTDIRTY); + + end = min(end, walk->vma->vm_end); + ptl = pmd_trans_huge_lock(pmd, vma); + if (ptl) { + if (dirty_vma || check_soft_dirty_pmd(vma, addr, pmd, false)) { + /* + * Break huge page into small pages if operation needs to be performed is + * on a portion of the huge page or the return buffer cannot store complete + * data. Then process this PMD as having normal pages. + */ + if (((p->flags & MEMWATCH_SD_CLEAR) && (end - addr < HPAGE_SIZE)) || + ((p->flags & MEMWATCH_SD_GET) && + (p->index + HPAGE_SIZE/PAGE_SIZE > p->vec_len))) { + spin_unlock(ptl); + split_huge_pmd(vma, pmd, addr); + goto process_pages; + } else { + dirty = check_soft_dirty_pmd(vma, addr, pmd, + p->flags & MEMWATCH_SD_CLEAR); + if ((p->flags & MEMWATCH_SD_GET) && (dirty_vma || dirty)) { + for (; addr != end && p->index < p->vec_len; + addr += PAGE_SIZE) + p->vec[p->index++] = addr - p->start; + } + } + } + spin_unlock(ptl); + return 0; + } + +process_pages: + if (pmd_trans_unstable(pmd)) + return 0; + + pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); + for (; addr != end; pte++, addr += PAGE_SIZE) { + dirty = check_soft_dirty(vma, addr, pte, p->flags & MEMWATCH_SD_CLEAR); + + if ((p->flags & MEMWATCH_SD_GET) && (dirty_vma || dirty)) { + p->vec[p->index++] = addr - p->start; + WARN_ON(p->index > p->vec_len); + } + } + pte_unmap_unlock(pte - 1, ptl); + cond_resched(); + + if (p->flags & MEMWATCH_SD_CLEAR) + flush_tlb_mm_range(vma->vm_mm, start, end, PAGE_SHIFT, false); + + return 0; +} + +static int memwatch_pte_hole(unsigned long addr, unsigned long end, int depth, + struct mm_walk *walk) +{ + struct memwatch_sd_private *p = walk->private; + struct vm_area_struct *vma = walk->vma; + + if (p->flags & MEMWATCH_SD_NO_REUSED_REGIONS) + return 0; + + if (vma && (vma->vm_flags & VM_SOFTDIRTY) && (p->flags & MEMWATCH_SD_GET)) { + for (; addr != end && p->index < p->vec_len; addr += PAGE_SIZE) + p->vec[p->index++] = addr - p->start; + } + + return 0; +} + +static int memwatch_pre_vma(unsigned long start, unsigned long end, struct mm_walk *walk) +{ + struct memwatch_sd_private *p = walk->private; + struct vm_area_struct *vma = walk->vma; + int ret; + unsigned long end_cut = end; + + if (p->flags & MEMWATCH_SD_NO_REUSED_REGIONS) + return 0; + + if ((p->flags & MEMWATCH_SD_CLEAR) && (vma->vm_flags & VM_SOFTDIRTY)) { + if (vma->vm_start < start) { + ret = split_vma(vma->vm_mm, vma, start, 1); + if (ret) + return ret; + } + + if (p->flags & MEMWATCH_SD_GET) + end_cut = min(start + p->vec_len * PAGE_SIZE, end); + + if (vma->vm_end > end_cut) { + ret = split_vma(vma->vm_mm, vma, end_cut, 0); + if (ret) + return ret; + } + } + + return 0; +} + +static void memwatch_post_vma(struct mm_walk *walk) +{ + struct memwatch_sd_private *p = walk->private; + struct vm_area_struct *vma = walk->vma; + + if (p->flags & MEMWATCH_SD_NO_REUSED_REGIONS) + return; + + if ((p->flags & MEMWATCH_SD_CLEAR) && (vma->vm_flags & VM_SOFTDIRTY)) { + vma->vm_flags &= ~VM_SOFTDIRTY; + vma_set_page_prot(vma); + } +} + +static int memwatch_pmd_test_walk(unsigned long start, unsigned long end, + struct mm_walk *walk) +{ + struct memwatch_sd_private *p = walk->private; + struct vm_area_struct *vma = walk->vma; + + if ((p->flags & MEMWATCH_SD_GET) && (p->index == p->vec_len)) + return -1; + + if (vma->vm_flags & VM_PFNMAP) + return 1; + + return 0; +} + +static const struct mm_walk_ops memwatch_ops = { + .test_walk = memwatch_pmd_test_walk, + .pre_vma = memwatch_pre_vma, + .pmd_entry = memwatch_pmd_entry, + .pte_hole = memwatch_pte_hole, + .post_vma = memwatch_post_vma, +}; + +static long do_process_memwatch(int pidfd, void __user *start_addr, int len, + unsigned int flags, loff_t __user *vec, int vec_len) +{ + struct memwatch_sd_private watch; + struct mmu_notifier_range range; + unsigned long start, end; + struct task_struct *task; + struct mm_struct *mm; + unsigned int f_flags; + int ret; + + start = (unsigned long)untagged_addr(start_addr); + if ((!IS_ALIGNED(start, PAGE_SIZE)) || !access_ok((void __user *)start, len)) + return -EINVAL; + + if ((flags == 0) || (flags == MEMWATCH_SD_NO_REUSED_REGIONS) || + (flags & ~MEMWATCH_SD_OPS_MASK)) + return -EINVAL; + + if ((flags & MEMWATCH_SD_GET) && ((vec_len == 0) || (!vec) || + !access_ok(vec, vec_len))) + return -EINVAL; + + end = start + len; + watch.start = start; + watch.flags = flags; + watch.index = 0; + watch.vec_len = vec_len; + + if (pidfd) { + task = pidfd_get_task(pidfd, &f_flags); + if (IS_ERR(task)) + return PTR_ERR(task); + } else { + task = current; + } + + if (flags & MEMWATCH_SD_GET) { + watch.vec = vzalloc(vec_len * sizeof(loff_t)); + if (!watch.vec) { + ret = -ENOMEM; + goto put_task; + } + } + + mm = mm_access(task, PTRACE_MODE_ATTACH_FSCREDS); + if (IS_ERR_OR_NULL(mm)) { + ret = mm ? PTR_ERR(mm) : -ESRCH; + goto free_watch; + } + + if (flags & MEMWATCH_SD_CLEAR) { + mmap_write_lock(mm); + + mmu_notifier_range_init(&range, MMU_NOTIFY_SOFT_DIRTY, 0, NULL, + mm, start, end); + mmu_notifier_invalidate_range_start(&range); + inc_tlb_flush_pending(mm); + } else { + mmap_read_lock(mm); + } + + ret = walk_page_range(mm, start, end, &memwatch_ops, &watch); + + if (flags & MEMWATCH_SD_CLEAR) { + mmu_notifier_invalidate_range_end(&range); + dec_tlb_flush_pending(mm); + + mmap_write_unlock(mm); + } else { + mmap_read_unlock(mm); + } + + mmput(mm); + + if (ret < 0) + goto free_watch; + + if (flags & MEMWATCH_SD_GET) { + ret = copy_to_user(vec, watch.vec, watch.index * sizeof(loff_t)); + if (ret) { + ret = -EIO; + goto free_watch; + } + ret = watch.index; + } else { + ret = 0; + } + +free_watch: + if (flags & MEMWATCH_SD_GET) + vfree(watch.vec); +put_task: + if (pidfd) + put_task_struct(task); + + return ret; +} +#endif + +SYSCALL_DEFINE6(process_memwatch, int, pidfd, void __user*, start, + int, len, unsigned int, flags, loff_t __user *, vec, int, vec_len) +{ + int ret = -EPERM; + +#ifdef CONFIG_MEM_SOFT_DIRTY + ret = do_process_memwatch(pidfd, start, len, flags, vec, vec_len); +#endif + return ret; +}

Several unit tests and functionality tests are included.

Signed-off-by: Muhammad Usama Anjum usama.anjum@collabora.com --- TAP version 13 1..44 ok 1 sanity_tests no flag specified ok 2 sanity_tests wrong flag specified ok 3 sanity_tests mixture of correct and wrong flags ok 4 sanity_tests wrong pidfd ok 5 sanity_tests pidfd of process with over which no capabilities ok 6 sanity_tests Clear area with larger vec size ok 7 Page testing: all new pages must be soft dirty ok 8 Page testing: all pages must not be soft dirty ok 9 Page testing: all pages dirty other than first and the last one ok 10 Page testing: only middle page dirty ok 11 Page testing: only two middle pages dirty ok 12 Page testing: only get 2 dirty pages and clear them as well ok 13 Page testing: Range clear only ok 14 Large Page testing: all new pages must be soft dirty ok 15 Large Page testing: all pages must not be soft dirty ok 16 Large Page testing: all pages dirty other than first and the last one ok 17 Large Page testing: only middle page dirty ok 18 Large Page testing: only two middle pages dirty ok 19 Large Page testing: only get 2 dirty pages and clear them as well ok 20 Large Page testing: Range clear only ok 21 Huge page testing: all new pages must be soft dirty ok 22 Huge page testing: all pages must not be soft dirty ok 23 Huge page testing: all pages dirty other than first and the last one ok 24 Huge page testing: only middle page dirty ok 25 Huge page testing: only two middle pages dirty ok 26 Huge page testing: only get 2 dirty pages and clear them as well ok 27 Huge page testing: Range clear only ok 28 Performance Page testing: page isn't dirty ok 29 Performance Page testing: all pages must not be soft dirty ok 30 Performance Page testing: all pages dirty other than first and the last one ok 31 Performance Page testing: only middle page dirty ok 32 Performance Page testing: only two middle pages dirty ok 33 Performance Page testing: only get 2 dirty pages and clear them as well ok 34 Performance Page testing: Range clear only ok 35 hpage_unit_tests all new huge page must be dirty ok 36 hpage_unit_tests all the huge page must not be dirty ok 37 hpage_unit_tests all the huge page must be dirty and clear ok 38 hpage_unit_tests only middle page dirty ok 39 hpage_unit_tests clear first half of huge page ok 40 hpage_unit_tests clear first half of huge page with limited buffer ok 41 hpage_unit_tests clear second half huge page ok 42 unmapped_region_tests Get dirty pages ok 43 unmapped_region_tests Get dirty pages ok 44 Test test_simple # Totals: pass:44 fail:0 xfail:0 xpass:0 skip:0 error:0 --- tools/testing/selftests/vm/.gitignore | 1 + tools/testing/selftests/vm/Makefile | 2 + tools/testing/selftests/vm/memwatch_test.c | 635 +++++++++++++++++++++ 3 files changed, 638 insertions(+) create mode 100644 tools/testing/selftests/vm/memwatch_test.c

diff --git a/tools/testing/selftests/vm/.gitignore b/tools/testing/selftests/vm/.gitignore index 31e5eea2a9b9..462cff7e23bb 100644 --- a/tools/testing/selftests/vm/.gitignore +++ b/tools/testing/selftests/vm/.gitignore @@ -14,6 +14,7 @@ mlock2-tests mrelease_test mremap_dontunmap mremap_test +memwatch_test on-fault-limit transhuge-stress protection_keys diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile index d9fa6a9ea584..65b8c94b104d 100644 --- a/tools/testing/selftests/vm/Makefile +++ b/tools/testing/selftests/vm/Makefile @@ -41,6 +41,7 @@ TEST_GEN_FILES += map_fixed_noreplace TEST_GEN_FILES += map_hugetlb TEST_GEN_FILES += map_populate TEST_GEN_FILES += memfd_secret +TEST_GEN_PROGS += memwatch_test TEST_GEN_FILES += migration TEST_GEN_FILES += mlock-random-test TEST_GEN_FILES += mlock2-tests @@ -98,6 +99,7 @@ TEST_FILES += va_128TBswitch.sh include ../lib.mk

$(OUTPUT)/madv_populate: vm_util.c +$(OUTPUT)/memwatch_test: vm_util.c $(OUTPUT)/soft-dirty: vm_util.c $(OUTPUT)/split_huge_page_test: vm_util.c

diff --git a/tools/testing/selftests/vm/memwatch_test.c b/tools/testing/selftests/vm/memwatch_test.c new file mode 100644 index 000000000000..a109eff5d807 --- /dev/null +++ b/tools/testing/selftests/vm/memwatch_test.c @@ -0,0 +1,635 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <stdio.h> +#include <fcntl.h> +#include <unistd.h> +#include <string.h> +#include <sys/mman.h> +#include <errno.h> +#include <malloc.h> +#include <asm-generic/unistd.h> +#include <linux/memwatch.h> +#include "vm_util.h" +#include "../kselftest.h" +#include <linux/types.h> + +#define TEST_ITERATIONS 10000 + +static long process_memwatch(pid_t pidfd, void *start, int len, + unsigned int flags, loff_t *vec, int vec_len) +{ + return syscall(__NR_process_memwatch, pidfd, start, len, flags, vec, vec_len); +} + +int sanity_tests(int page_size) +{ + char *mem; + int mem_size, vec_size, ret; + loff_t *vec; + + /* 1. wrong operation */ + vec_size = 100; + mem_size = page_size; + + vec = malloc(sizeof(loff_t) * vec_size); + mem = mmap(NULL, mem_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0); + if (!mem || !vec) + ksft_exit_fail_msg("error nomem\n"); + + ksft_test_result(process_memwatch(0, mem, mem_size, 0, vec, vec_size) < 0, + "%s no flag specified\n", __func__); + ksft_test_result(process_memwatch(0, mem, mem_size, 0x01000000, vec, vec_size) < 0, + "%s wrong flag specified\n", __func__); + ksft_test_result(process_memwatch(0, mem, mem_size, MEMWATCH_SD_GET | 0xFF, + vec, vec_size) < 0, + "%s mixture of correct and wrong flags\n", __func__); + ksft_test_result(process_memwatch(-1, mem, mem_size, MEMWATCH_SD_GET, vec, vec_size) < 0, + "%s wrong pidfd\n", __func__); + ksft_test_result(process_memwatch(1, mem, mem_size, MEMWATCH_SD_GET, vec, vec_size) < 0, + "%s pidfd of process with over which no capabilities\n", __func__); + + /* 2. Clear area with larger vec size */ + ret = process_memwatch(0, mem, mem_size, MEMWATCH_SD_GET | MEMWATCH_SD_CLEAR, + vec, vec_size); + ksft_test_result(ret >= 0, "%s Clear area with larger vec size\n", __func__); + + free(vec); + munmap(mem, mem_size); + return 0; +} + +void *gethugepage(int map_size) +{ + int ret; + char *map; + size_t hpage_len = read_pmd_pagesize(); + + map = memalign(hpage_len, map_size); + if (!map) + ksft_exit_fail_msg("memalign failed %d %s\n", errno, strerror(errno)); + + ret = madvise(map, map_size, MADV_HUGEPAGE); + if (ret) + ksft_exit_fail_msg("madvise failed %d %d %s\n", ret, errno, strerror(errno)); + + memset(map, 0, map_size); + + if (check_huge(map)) + return map; + + free(map); + return NULL; + +} + +int hpage_unit_tests(int page_size) +{ + char *map; + int i, ret; + size_t hpage_len = read_pmd_pagesize(); + size_t num_pages = 1; + int map_size = hpage_len * num_pages; + int vec_size = map_size/page_size; + loff_t *vec, *vec2; + + vec = malloc(sizeof(loff_t) * vec_size); + vec2 = malloc(sizeof(loff_t) * vec_size); + if (!vec || !vec2) + ksft_exit_fail_msg("malloc failed\n"); + + map = gethugepage(map_size); + if (map) { + // 1. all new huge page must be dirty + ret = process_memwatch(0, map, map_size, MEMWATCH_SD_GET | MEMWATCH_SD_CLEAR, + vec, vec_size); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + for (i = 0; i < vec_size; i++) + if (vec[i] != i * page_size) + break; + + ksft_test_result(i == vec_size, "%s all new huge page must be dirty\n", __func__); + + // 2. all the huge page must not be dirty + ret = process_memwatch(0, map, map_size, MEMWATCH_SD_GET, + vec, vec_size); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + ksft_test_result(ret == 0, "%s all the huge page must not be dirty\n", __func__); + + // 3. all the huge page must be dirty and clear dirty as well + memset(map, -1, map_size); + ret = process_memwatch(0, map, map_size, MEMWATCH_SD_GET | MEMWATCH_SD_CLEAR, + vec, vec_size); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + for (i = 0; i < vec_size; i++) + if (vec[i] != i * page_size) + break; + + ksft_test_result(ret == vec_size && i == vec_size, + "%s all the huge page must be dirty and clear\n", __func__); + + // 4. only middle page dirty + free(map); + map = gethugepage(map_size); + clear_softdirty(); + map[vec_size/2 * page_size]++; + + ret = process_memwatch(0, map, map_size, MEMWATCH_SD_GET, vec, vec_size); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + for (i = 0; i < vec_size; i++) { + if (vec[i] == vec_size/2 * page_size) + break; + } + ksft_test_result(vec[i] == vec_size/2 * page_size, + "%s only middle page dirty\n", __func__); + + free(map); + } else { + ksft_test_result_skip("all new huge page must be dirty\n"); + ksft_test_result_skip("all the huge page must not be dirty\n"); + ksft_test_result_skip("all the huge page must be dirty and clear\n"); + ksft_test_result_skip("only middle page dirty\n"); + } + + // 5. clear first half of huge page + map = gethugepage(map_size); + if (map) { + ret = process_memwatch(0, map, map_size/2, MEMWATCH_SD_CLEAR, NULL, 0); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + ret = process_memwatch(0, map, map_size, MEMWATCH_SD_GET, vec, vec_size); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + for (i = 0; i < vec_size/2; i++) + if (vec[i] != (i + vec_size/2) * page_size) + break; + + ksft_test_result(i == vec_size/2 && ret == vec_size/2, + "%s clear first half of huge page\n", __func__); + free(map); + } else { + ksft_test_result_skip("clear first half of huge page\n"); + } + + // 6. clear first half of huge page with limited buffer + map = gethugepage(map_size); + if (map) { + ret = process_memwatch(0, map, map_size, MEMWATCH_SD_CLEAR | MEMWATCH_SD_GET, + vec, vec_size/2); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + ret = process_memwatch(0, map, map_size, MEMWATCH_SD_GET, vec, vec_size); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + for (i = 0; i < vec_size/2; i++) + if (vec[i] != (i + vec_size/2) * page_size) + break; + + ksft_test_result(i == vec_size/2 && ret == vec_size/2, + "%s clear first half of huge page with limited buffer\n", + __func__); + free(map); + } else { + ksft_test_result_skip("clear first half of huge page with limited buffer\n"); + } + + // 7. clear second half of huge page + map = gethugepage(map_size); + if (map) { + memset(map, -1, map_size); + ret = process_memwatch(0, map + map_size/2, map_size/2, MEMWATCH_SD_CLEAR, NULL, 0); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + ret = process_memwatch(0, map, map_size, MEMWATCH_SD_GET, vec, vec_size); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + for (i = 0; i < vec_size/2; i++) + if (vec[i] != i * page_size) + break; + + ksft_test_result(i == vec_size/2, "%s clear second half huge page\n", __func__); + free(map); + } else { + ksft_test_result_skip("clear second half huge page\n"); + } + + free(vec); + free(vec2); + return 0; +} + +int base_tests(char *prefix, char *mem, int mem_size, int page_size, int skip) +{ + int vec_size, i, j, ret, dirty_pages, dirty_pages2; + loff_t *vec, *vec2; + + if (skip) { + ksft_test_result_skip("%s all new pages must be soft dirty\n", prefix); + ksft_test_result_skip("%s all pages must not be soft dirty\n", prefix); + ksft_test_result_skip("%s all pages dirty other than first and the last one\n", + prefix); + ksft_test_result_skip("%s only middle page dirty\n", prefix); + ksft_test_result_skip("%s only two middle pages dirty\n", prefix); + ksft_test_result_skip("%s only get 2 dirty pages and clear them as well\n", prefix); + ksft_test_result_skip("%s Range clear only\n", prefix); + return 0; + } + + vec_size = mem_size/page_size; + vec = malloc(sizeof(loff_t) * vec_size); + vec2 = malloc(sizeof(loff_t) * vec_size); + + /* 1. all new pages must be soft dirty and clear the range for next test */ + dirty_pages = process_memwatch(0, mem, mem_size, MEMWATCH_SD_GET | MEMWATCH_SD_CLEAR, + vec, vec_size - 2); + if (dirty_pages < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty_pages, errno, strerror(errno)); + + dirty_pages2 = process_memwatch(0, mem, mem_size, MEMWATCH_SD_GET | MEMWATCH_SD_CLEAR, + vec2, vec_size); + if (dirty_pages2 < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty_pages2, errno, strerror(errno)); + + for (i = 0; i < dirty_pages; i++) + if (vec[i] != i * page_size) + break; + for (j = 0; j < dirty_pages2; j++) + if (vec2[j] != (j + vec_size - 2) * page_size) + break; + + ksft_test_result(dirty_pages == vec_size - 2 && i == dirty_pages && + dirty_pages2 == 2 && j == dirty_pages2, + "%s all new pages must be soft dirty\n", prefix); + + // 2. all pages must not be soft dirty + dirty_pages = process_memwatch(0, mem, mem_size, MEMWATCH_SD_GET, vec, vec_size); + if (dirty_pages < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty_pages, errno, strerror(errno)); + + ksft_test_result(dirty_pages == 0, "%s all pages must not be soft dirty\n", prefix); + + // 3. all pages dirty other than first and the last one + memset(mem + page_size, -1, (mem_size - 2 * page_size)); + + dirty_pages = process_memwatch(0, mem, mem_size, MEMWATCH_SD_GET, vec, vec_size); + if (dirty_pages < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty_pages, errno, strerror(errno)); + + for (i = 0; i < dirty_pages; i++) { + if (vec[i] != (i + 1) * page_size) + break; + } + + ksft_test_result(dirty_pages == vec_size - 2 && i == vec_size - 2, + "%s all pages dirty other than first and the last one\n", prefix); + + // 4. only middle page dirty + clear_softdirty(); + mem[vec_size/2 * page_size]++; + + dirty_pages = process_memwatch(0, mem, mem_size, MEMWATCH_SD_GET, vec, vec_size); + if (dirty_pages < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty_pages, errno, strerror(errno)); + + for (i = 0; i < vec_size; i++) { + if (vec[i] == vec_size/2 * page_size) + break; + } + ksft_test_result(vec[i] == vec_size/2 * page_size, + "%s only middle page dirty\n", prefix); + + // 5. only two middle pages dirty and walk over only middle pages + clear_softdirty(); + mem[vec_size/2 * page_size]++; + mem[(vec_size/2 + 1) * page_size]++; + + dirty_pages = process_memwatch(0, &mem[vec_size/2 * page_size], 2 * page_size, + MEMWATCH_SD_GET, vec, vec_size); + if (dirty_pages < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty_pages, errno, strerror(errno)); + + ksft_test_result(dirty_pages == 2 && vec[0] == 0 && vec[1] == page_size, + "%s only two middle pages dirty\n", prefix); + + /* 6. only get 2 dirty pages and clear them as well */ + memset(mem, -1, mem_size); + + /* get and clear second and third pages */ + ret = process_memwatch(0, mem + page_size, 2 * page_size, + MEMWATCH_SD_GET | MEMWATCH_SD_CLEAR, vec, 2); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + dirty_pages = process_memwatch(0, mem, mem_size, MEMWATCH_SD_GET, + vec2, vec_size); + if (dirty_pages < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty_pages, errno, strerror(errno)); + + for (i = 0; i < vec_size - 2; i++) { + if (i == 0 && (vec[i] != 0 || vec2[i] != 0)) + break; + else if (i == 1 && (vec[i] != page_size || vec2[i] != (i + 2) * page_size)) + break; + else if (i > 1 && (vec2[i] != (i + 2) * page_size)) + break; + } + + ksft_test_result(dirty_pages == vec_size - 2 && i == vec_size - 2, + "%s only get 2 dirty pages and clear them as well\n", prefix); + /* 7. Range clear only */ + memset(mem, -1, mem_size); + dirty_pages = process_memwatch(0, mem, mem_size, MEMWATCH_SD_CLEAR, NULL, 0); + if (dirty_pages < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty_pages, errno, strerror(errno)); + + dirty_pages2 = process_memwatch(0, mem, mem_size, MEMWATCH_SD_GET, vec, vec_size); + if (dirty_pages2 < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty_pages2, errno, strerror(errno)); + + ksft_test_result(dirty_pages == 0 && dirty_pages2 == 0, "%s Range clear only\n", + prefix); + + free(vec); + free(vec2); + return 0; +} + +int performance_base_tests(char *prefix, char *mem, int mem_size, int page_size, int skip) +{ + int vec_size, i, ret, dirty_pages, dirty_pages2; + loff_t *vec, *vec2; + + if (skip) { + ksft_test_result_skip("%s all new pages must be soft dirty\n", prefix); + ksft_test_result_skip("%s all pages must not be soft dirty\n", prefix); + ksft_test_result_skip("%s all pages dirty other than first and the last one\n", + prefix); + ksft_test_result_skip("%s only middle page dirty\n", prefix); + ksft_test_result_skip("%s only two middle pages dirty\n", prefix); + ksft_test_result_skip("%s only get 2 dirty pages and clear them as well\n", prefix); + ksft_test_result_skip("%s Range clear only\n", prefix); + return 0; + } + + vec_size = mem_size/page_size; + vec = malloc(sizeof(loff_t) * vec_size); + vec2 = malloc(sizeof(loff_t) * vec_size); + + /* 1. all new pages must be soft dirty and clear the range for next test */ + dirty_pages = process_memwatch(0, mem, mem_size, + MEMWATCH_SD_GET | MEMWATCH_SD_CLEAR | + MEMWATCH_SD_NO_REUSED_REGIONS, + vec, vec_size - 2); + if (dirty_pages < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty_pages, errno, strerror(errno)); + + dirty_pages2 = process_memwatch(0, mem, mem_size, + MEMWATCH_SD_GET | MEMWATCH_SD_CLEAR | + MEMWATCH_SD_NO_REUSED_REGIONS, + vec2, vec_size); + if (dirty_pages2 < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty_pages2, errno, strerror(errno)); + + ksft_test_result(dirty_pages == 0 && dirty_pages2 == 0, + "%s page isn't dirty\n", prefix); + + // 2. all pages must not be soft dirty + dirty_pages = process_memwatch(0, mem, mem_size, + MEMWATCH_SD_GET | MEMWATCH_SD_NO_REUSED_REGIONS, + vec, vec_size); + if (dirty_pages < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty_pages, errno, strerror(errno)); + + ksft_test_result(dirty_pages == 0, "%s all pages must not be soft dirty\n", prefix); + + // 3. all pages dirty other than first and the last one + memset(mem + page_size, -1, (mem_size - 2 * page_size)); + + dirty_pages = process_memwatch(0, mem, mem_size, + MEMWATCH_SD_GET | MEMWATCH_SD_NO_REUSED_REGIONS, + vec, vec_size); + if (dirty_pages < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty_pages, errno, strerror(errno)); + + for (i = 0; i < dirty_pages; i++) { + if (vec[i] != (i + 1) * page_size) + break; + } + + ksft_test_result(dirty_pages == vec_size - 2 && i == vec_size - 2, + "%s all pages dirty other than first and the last one\n", prefix); + + // 4. only middle page dirty + clear_softdirty(); + mem[vec_size/2 * page_size]++; + + dirty_pages = process_memwatch(0, mem, mem_size, + MEMWATCH_SD_GET | MEMWATCH_SD_NO_REUSED_REGIONS, + vec, vec_size); + if (dirty_pages < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty_pages, errno, strerror(errno)); + + for (i = 0; i < vec_size; i++) { + if (vec[i] == vec_size/2 * page_size) + break; + } + ksft_test_result(vec[i] == vec_size/2 * page_size, + "%s only middle page dirty\n", prefix); + + // 5. only two middle pages dirty and walk over only middle pages + clear_softdirty(); + mem[vec_size/2 * page_size]++; + mem[(vec_size/2 + 1) * page_size]++; + + dirty_pages = process_memwatch(0, &mem[vec_size/2 * page_size], 2 * page_size, + MEMWATCH_SD_GET | MEMWATCH_SD_NO_REUSED_REGIONS, + vec, vec_size); + if (dirty_pages < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty_pages, errno, strerror(errno)); + + ksft_test_result(dirty_pages == 2 && vec[0] == 0 && vec[1] == page_size, + "%s only two middle pages dirty\n", prefix); + + /* 6. only get 2 dirty pages and clear them as well */ + memset(mem, -1, mem_size); + + /* get and clear second and third pages */ + ret = process_memwatch(0, mem + page_size, 2 * page_size, + MEMWATCH_SD_GET | MEMWATCH_SD_CLEAR | MEMWATCH_SD_NO_REUSED_REGIONS, + vec, 2); + if (ret < 0) + ksft_exit_fail_msg("error %d %d %s\n", ret, errno, strerror(errno)); + + dirty_pages = process_memwatch(0, mem, mem_size, + MEMWATCH_SD_GET | MEMWATCH_SD_NO_REUSED_REGIONS, + vec2, vec_size); + if (dirty_pages < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty_pages, errno, strerror(errno)); + + for (i = 0; i < vec_size - 2; i++) { + if (i == 0 && (vec[i] != 0 || vec2[i] != 0)) + break; + else if (i == 1 && (vec[i] != page_size || vec2[i] != (i + 2) * page_size)) + break; + else if (i > 1 && (vec2[i] != (i + 2) * page_size)) + break; + } + + ksft_test_result(dirty_pages == vec_size - 2 && i == vec_size - 2, + "%s only get 2 dirty pages and clear them as well\n", prefix); + /* 7. Range clear only */ + memset(mem, -1, mem_size); + dirty_pages = process_memwatch(0, mem, mem_size, + MEMWATCH_SD_CLEAR | MEMWATCH_SD_NO_REUSED_REGIONS, + NULL, 0); + if (dirty_pages < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty_pages, errno, strerror(errno)); + + dirty_pages2 = process_memwatch(0, mem, mem_size, + MEMWATCH_SD_GET | MEMWATCH_SD_NO_REUSED_REGIONS, + vec, vec_size); + if (dirty_pages2 < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty_pages2, errno, strerror(errno)); + + ksft_test_result(dirty_pages == 0 && dirty_pages2 == 0, "%s Range clear only\n", + prefix); + + free(vec); + free(vec2); + return 0; +} + +int unmapped_region_tests(int page_size) +{ + void *start = (void *)0x10000000; + int dirty_pages, len = 0x00040000; + int vec_size = len / page_size; + loff_t *vec = malloc(sizeof(loff_t) * vec_size); + + /* 1. Get dirty pages */ + dirty_pages = process_memwatch(0, start, len, MEMWATCH_SD_GET, vec, vec_size); + if (dirty_pages < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty_pages, errno, strerror(errno)); + + ksft_test_result(dirty_pages >= 0, "%s Get dirty pages\n", __func__); + + /* 2. Clear dirty bit of whole address space */ + dirty_pages = process_memwatch(0, 0, 0x7FFFFFFF, MEMWATCH_SD_CLEAR, NULL, 0); + if (dirty_pages < 0) + ksft_exit_fail_msg("error %d %d %s\n", dirty_pages, errno, strerror(errno)); + + ksft_test_result(dirty_pages == 0, "%s Get dirty pages\n", __func__); + + free(vec); + return 0; +} + +static void test_simple(int page_size) +{ + int i; + char *map; + loff_t *vec = NULL; + + map = aligned_alloc(page_size, page_size); + if (!map) + ksft_exit_fail_msg("mmap failed\n"); + + clear_softdirty(); + + for (i = 0 ; i < TEST_ITERATIONS; i++) { + if (process_memwatch(0, map, page_size, MEMWATCH_SD_GET, vec, 1) == 1) { + ksft_print_msg("dirty bit was 1, but should be 0 (i=%d)\n", i); + break; + } + + clear_softdirty(); + // Write something to the page to get the dirty bit enabled on the page + map[0]++; + + if (process_memwatch(0, map, page_size, MEMWATCH_SD_GET, vec, 1) == 0) { + ksft_print_msg("dirty bit was 0, but should be 1 (i=%d)\n", i); + break; + } + + clear_softdirty(); + } + free(map); + + ksft_test_result(i == TEST_ITERATIONS, "Test %s\n", __func__); +} + +int main(int argc, char **argv) +{ + int page_size = getpagesize(); + size_t hpage_len = read_pmd_pagesize(); + char *mem, *map; + int mem_size; + + ksft_print_header(); + ksft_set_plan(44); + + /* 1. Sanity testing */ + sanity_tests(page_size); + + /* 2. Normal page testing */ + mem_size = 10 * page_size; + mem = mmap(NULL, mem_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0); + if (!mem) + ksft_exit_fail_msg("error nomem\n"); + + base_tests("Page testing:", mem, mem_size, page_size, 0); + + munmap(mem, mem_size); + + /* 3. Large page testing */ + mem_size = 512 * 10 * page_size; + mem = mmap(NULL, mem_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0); + if (!mem) + ksft_exit_fail_msg("error nomem\n"); + + base_tests("Large Page testing:", mem, mem_size, page_size, 0); + + munmap(mem, mem_size); + + /* 4. Huge page testing */ + map = gethugepage(hpage_len); + if (check_huge(map)) + base_tests("Huge page testing:", map, hpage_len, page_size, 0); + else + base_tests("Huge page testing:", NULL, 0, 0, 1); + + free(map); + + /* 5. Normal page testing */ + mem_size = 10 * page_size; + mem = mmap(NULL, mem_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0); + if (!mem) + ksft_exit_fail_msg("error nomem\n"); + + performance_base_tests("Performance Page testing:", mem, mem_size, page_size, 0); + + munmap(mem, mem_size); + + /* 6. Huge page tests */ + hpage_unit_tests(page_size); + + /* 7. Unmapped address test */ + unmapped_region_tests(page_size); + + /* 8. Iterative test */ + test_simple(page_size); + + return ksft_exit_pass(); +}