lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <955e0b9682b1746c528a043f0ca530b54ee22536.1755677674.git.baolin.wang@linux.alibaba.com>
Date: Wed, 20 Aug 2025 17:07:20 +0800
From: Baolin Wang <baolin.wang@...ux.alibaba.com>
To: akpm@...ux-foundation.org,
	hughd@...gle.com,
	david@...hat.com,
	lorenzo.stoakes@...cle.com
Cc: ziy@...dia.com,
	Liam.Howlett@...cle.com,
	npache@...hat.com,
	ryan.roberts@....com,
	dev.jain@....com,
	baohua@...nel.org,
	baolin.wang@...ux.alibaba.com,
	linux-mm@...ck.org,
	linux-kernel@...r.kernel.org
Subject: [RFC PATCH 09/11] selftests: mm: move gather_after_split_folio_orders() into vm_util.c file

Move gather_after_split_folio_orders() to vm_util.c as a helper function
in preparation for implementing checks for mTHP collapse. While we are
at it, rename this function to indicate that it is not only used for
large folio splits.

No functional changes.

Signed-off-by: Baolin Wang <baolin.wang@...ux.alibaba.com>
---
 .../selftests/mm/split_huge_page_test.c       | 125 +-----------------
 tools/testing/selftests/mm/vm_util.c          | 123 +++++++++++++++++
 tools/testing/selftests/mm/vm_util.h          |   2 +
 3 files changed, 126 insertions(+), 124 deletions(-)

diff --git a/tools/testing/selftests/mm/split_huge_page_test.c b/tools/testing/selftests/mm/split_huge_page_test.c
index cbf190598988..77cf510f18e0 100644
--- a/tools/testing/selftests/mm/split_huge_page_test.c
+++ b/tools/testing/selftests/mm/split_huge_page_test.c
@@ -104,129 +104,6 @@ static bool is_backed_by_folio(char *vaddr, int order, int pagemap_fd,
 	return false;
 }
 
-static int vaddr_pageflags_get(char *vaddr, int pagemap_fd, int kpageflags_fd,
-		uint64_t *flags)
-{
-	unsigned long pfn;
-
-	pfn = pagemap_get_pfn(pagemap_fd, vaddr);
-
-	/* non-present PFN */
-	if (pfn == -1UL)
-		return 1;
-
-	if (pageflags_get(pfn, kpageflags_fd, flags))
-		return -1;
-
-	return 0;
-}
-
-/*
- * gather_after_split_folio_orders - scan through [vaddr_start, len) and record
- * folio orders
- *
- * @vaddr_start: start vaddr
- * @len: range length
- * @pagemap_fd: file descriptor to /proc/<pid>/pagemap
- * @kpageflags_fd: file descriptor to /proc/kpageflags
- * @orders: output folio order array
- * @nr_orders: folio order array size
- *
- * gather_after_split_folio_orders() scan through [vaddr_start, len) and check
- * all folios within the range and record their orders. All order-0 pages will
- * be recorded. Non-present vaddr is skipped.
- *
- * NOTE: the function is used to check folio orders after a split is performed,
- * so it assumes [vaddr_start, len) fully maps to after-split folios within that
- * range.
- *
- * Return: 0 - no error, -1 - unhandled cases
- */
-static int gather_after_split_folio_orders(char *vaddr_start, size_t len,
-		int pagemap_fd, int kpageflags_fd, int orders[], int nr_orders)
-{
-	uint64_t page_flags = 0;
-	int cur_order = -1;
-	char *vaddr;
-
-	if (pagemap_fd == -1 || kpageflags_fd == -1)
-		return -1;
-	if (!orders)
-		return -1;
-	if (nr_orders <= 0)
-		return -1;
-
-	for (vaddr = vaddr_start; vaddr < vaddr_start + len;) {
-		char *next_folio_vaddr;
-		int status;
-
-		status = vaddr_pageflags_get(vaddr, pagemap_fd, kpageflags_fd,
-					&page_flags);
-		if (status < 0)
-			return -1;
-
-		/* skip non present vaddr */
-		if (status == 1) {
-			vaddr += psize();
-			continue;
-		}
-
-		/* all order-0 pages with possible false postive (non folio) */
-		if (!(page_flags & (KPF_COMPOUND_HEAD | KPF_COMPOUND_TAIL))) {
-			orders[0]++;
-			vaddr += psize();
-			continue;
-		}
-
-		/* skip non thp compound pages */
-		if (!(page_flags & KPF_THP)) {
-			vaddr += psize();
-			continue;
-		}
-
-		/* vpn points to part of a THP at this point */
-		if (page_flags & KPF_COMPOUND_HEAD)
-			cur_order = 1;
-		else {
-			vaddr += psize();
-			continue;
-		}
-
-		next_folio_vaddr = vaddr + (1UL << (cur_order + pshift()));
-
-		if (next_folio_vaddr >= vaddr_start + len)
-			break;
-
-		while ((status = vaddr_pageflags_get(next_folio_vaddr,
-						     pagemap_fd, kpageflags_fd,
-						     &page_flags)) >= 0) {
-			/*
-			 * non present vaddr, next compound head page, or
-			 * order-0 page
-			 */
-			if (status == 1 ||
-			    (page_flags & KPF_COMPOUND_HEAD) ||
-			    !(page_flags & (KPF_COMPOUND_HEAD | KPF_COMPOUND_TAIL))) {
-				if (cur_order < nr_orders) {
-					orders[cur_order]++;
-					cur_order = -1;
-					vaddr = next_folio_vaddr;
-				}
-				break;
-			}
-
-			cur_order++;
-			next_folio_vaddr = vaddr + (1UL << (cur_order + pshift()));
-		}
-
-		if (status < 0)
-			return status;
-	}
-	if (cur_order > 0 && cur_order < nr_orders)
-		orders[cur_order]++;
-	return 0;
-}
-
 static int check_after_split_folio_orders(char *vaddr_start, size_t len,
 		int pagemap_fd, int kpageflags_fd, int orders[], int nr_orders)
 {
@@ -240,7 +117,7 @@ static int check_after_split_folio_orders(char *vaddr_start, size_t len,
 		ksft_exit_fail_msg("Cannot allocate memory for vaddr_orders");
 
 	memset(vaddr_orders, 0, sizeof(int) * nr_orders);
-	status = gather_after_split_folio_orders(vaddr_start, len, pagemap_fd,
+	status = gather_folio_orders(vaddr_start, len, pagemap_fd,
 				     kpageflags_fd, vaddr_orders, nr_orders);
 	if (status)
 		ksft_exit_fail_msg("gather folio info failed\n");
diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c
index 6058d80c63ef..853c8a4caa1d 100644
--- a/tools/testing/selftests/mm/vm_util.c
+++ b/tools/testing/selftests/mm/vm_util.c
@@ -195,6 +195,129 @@ unsigned long rss_anon(void)
 	return rss_anon;
 }
 
+static int vaddr_pageflags_get(char *vaddr, int pagemap_fd, int kpageflags_fd,
+		uint64_t *flags)
+{
+	unsigned long pfn;
+
+	pfn = pagemap_get_pfn(pagemap_fd, vaddr);
+
+	/* non-present PFN */
+	if (pfn == -1UL)
+		return 1;
+
+	if (pageflags_get(pfn, kpageflags_fd, flags))
+		return -1;
+
+	return 0;
+}
+
+/*
+ * gather_folio_orders - scan through [vaddr_start, len) and record
+ * folio orders
+ *
+ * @vaddr_start: start vaddr
+ * @len: range length
+ * @pagemap_fd: file descriptor to /proc/<pid>/pagemap
+ * @kpageflags_fd: file descriptor to /proc/kpageflags
+ * @orders: output folio order array
+ * @nr_orders: folio order array size
+ *
+ * gather_after_split_folio_orders() scan through [vaddr_start, len) and check
+ * all folios within the range and record their orders. All order-0 pages will
+ * be recorded. Non-present vaddr is skipped.
+ *
+ * NOTE: the function is used to check folio orders after a split is performed,
+ * so it assumes [vaddr_start, len) fully maps to after-split folios within that
+ * range.
+ *
+ * Return: 0 - no error, -1 - unhandled cases
+ */
+int gather_folio_orders(char *vaddr_start, size_t len,
+		int pagemap_fd, int kpageflags_fd, int orders[], int nr_orders)
+{
+	uint64_t page_flags = 0;
+	int cur_order = -1;
+	char *vaddr;
+
+	if (pagemap_fd == -1 || kpageflags_fd == -1)
+		return -1;
+	if (!orders)
+		return -1;
+	if (nr_orders <= 0)
+		return -1;
+
+	for (vaddr = vaddr_start; vaddr < vaddr_start + len;) {
+		char *next_folio_vaddr;
+		int status;
+
+		status = vaddr_pageflags_get(vaddr, pagemap_fd, kpageflags_fd,
+				&page_flags);
+		if (status < 0)
+			return -1;
+
+		/* skip non present vaddr */
+		if (status == 1) {
+			vaddr += psize();
+			continue;
+		}
+
+		/* all order-0 pages with possible false postive (non folio) */
+		if (!(page_flags & (KPF_COMPOUND_HEAD | KPF_COMPOUND_TAIL))) {
+			orders[0]++;
+			vaddr += psize();
+			continue;
+		}
+
+		/* skip non thp compound pages */
+		if (!(page_flags & KPF_THP)) {
+			vaddr += psize();
+			continue;
+		}
+
+		/* vpn points to part of a THP at this point */
+		if (page_flags & KPF_COMPOUND_HEAD)
+			cur_order = 1;
+		else {
+			vaddr += psize();
+			continue;
+		}
+
+		next_folio_vaddr = vaddr + (1UL << (cur_order + pshift()));
+
+		if (next_folio_vaddr >= vaddr_start + len)
+			break;
+
+		while ((status = vaddr_pageflags_get(next_folio_vaddr,
+						     pagemap_fd, kpageflags_fd,
+						     &page_flags)) >= 0) {
+			/*
+			 * non present vaddr, next compound head page, or
+			 * order-0 page
+			 */
+			if (status == 1 ||
+			    (page_flags & KPF_COMPOUND_HEAD) ||
+			    !(page_flags & (KPF_COMPOUND_HEAD | KPF_COMPOUND_TAIL))) {
+				if (cur_order < nr_orders) {
+					orders[cur_order]++;
+					cur_order = -1;
+					vaddr = next_folio_vaddr;
+				}
+				break;
+			}
+
+			cur_order++;
+			next_folio_vaddr = vaddr + (1UL << (cur_order + pshift()));
+		}
+
+		if (status < 0)
+			return status;
+	}
+	if (cur_order > 0 && cur_order < nr_orders)
+		orders[cur_order]++;
+	return 0;
+}
+
 char *__get_smap_entry(void *addr, const char *pattern, char *buf, size_t len)
 {
 	int ret;
diff --git a/tools/testing/selftests/mm/vm_util.h b/tools/testing/selftests/mm/vm_util.h
index a1cd446e5140..197a9b69cbba 100644
--- a/tools/testing/selftests/mm/vm_util.h
+++ b/tools/testing/selftests/mm/vm_util.h
@@ -89,6 +89,8 @@ int64_t allocate_transhuge(void *ptr, int pagemap_fd);
 unsigned long default_huge_page_size(void);
 int detect_hugetlb_page_sizes(size_t sizes[], int max);
 int pageflags_get(unsigned long pfn, int kpageflags_fd, uint64_t *flags);
+int gather_folio_orders(char *vaddr_start, size_t len,
+		int pagemap_fd, int kpageflags_fd, int orders[], int nr_orders);
 
 int uffd_register(int uffd, void *addr, uint64_t len,
 		  bool miss, bool wp, bool minor);
-- 
2.43.5


Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ