+ mm-gup-check-if-both-gup_get-and-gup_pin-are-set-in-__get_user_pages-earlier.patch added to mm-new branch

+ mm-gup-check-if-both-gup_get-and-gup_pin-are-set-in-__get_user_pages-earlier.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: mm/gup: check if both GUP_GET and GUP_PIN are set in __get_user_pages() earlier
has been added to the -mm mm-new branch.  Its filename is
     mm-gup-check-if-both-gup_get-and-gup_pin-are-set-in-__get_user_pages-earlier.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-gup-check-if-both-gup_get-and-gup_pin-are-set-in-__get_user_pages-earlier.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Baoquan He <bhe@redhat.com>
Subject: mm/gup: check if both GUP_GET and GUP_PIN are set in __get_user_pages() earlier
Date: Mon, 31 Mar 2025 16:13:22 +0800

In __get_user_pages(), it will traverse page table and take a reference to
the page the given user address corresponds to if GUP_GET or GUP_PIN is
et.  However, it's not supported both GUP_GET and GUP_PIN are set.  This
check should be done earlier, but not doing it till entering into
follow_page_pte() and failed.

Here move the checking to the beginning of __get_user_pages().

Link: https://lkml.kernel.org/r/20250331081327.256412-3-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: <x86@kernel.org>
Cc: Yanjun.Zhu <yanjun.zhu@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/gup.c |   10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

--- a/mm/gup.c~mm-gup-check-if-both-gup_get-and-gup_pin-are-set-in-__get_user_pages-earlier
+++ a/mm/gup.c
@@ -844,11 +844,6 @@ static struct page *follow_page_pte(stru
 	pte_t *ptep, pte;
 	int ret;
 
-	/* FOLL_GET and FOLL_PIN are mutually exclusive. */
-	if (WARN_ON_ONCE((flags & (FOLL_PIN | FOLL_GET)) ==
-			 (FOLL_PIN | FOLL_GET)))
-		return ERR_PTR(-EINVAL);
-
 	ptep = pte_offset_map_lock(mm, pmd, address, &ptl);
 	if (!ptep)
 		return no_page_table(vma, flags, address);
@@ -1434,6 +1429,11 @@ static long __get_user_pages(struct mm_s
 
 	VM_BUG_ON(!!pages != !!(gup_flags & (FOLL_GET | FOLL_PIN)));
 
+	/* FOLL_GET and FOLL_PIN are mutually exclusive. */
+	if (WARN_ON_ONCE((gup_flags & (FOLL_PIN | FOLL_GET)) ==
+			 (FOLL_PIN | FOLL_GET)))
+		return -EINVAL;
+
 	do {
 		struct page *page;
 		unsigned int page_increm;
_

Patches currently in -mm which might be from bhe@redhat.com are

mm-gup-fix-wrongly-calculated-returned-value-in-fault_in_safe_writeable.patch
mm-gup-check-if-both-gup_get-and-gup_pin-are-set-in-__get_user_pages-earlier.patch
mm-gup-fix-the-outdated-code-comments-above-get_user_pages_unlocked.patch
mm-gup-remove-gup_fast_pgd_leaf-and-clean-up-the-relevant-codes.patch
x86-mm-remove-pgd_leaf-definition-in-arch.patch
x86-mm-remove-p4d_leaf-definition.patch
mm-pgtable-remove-unneeded-pgd_devmap.patch