From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0626725CC40; Mon, 1 Dec 2025 11:33:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764588834; cv=none; b=SX40YyUR5/dVWky3squZExHyrRGHqoHBnCY8uW1baqR4Q+XJ6HjpJZAZYrWe4QMebrOCl8oUnhVMrlGmdCGhyKjB6emJCGtQ6acwYL90P0MhnOq/P3eA1zCvQUuLe8myZMByz8omNPkLlWzrc4Im4nju5aSCFpgBNGErmxPHw+A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764588834; c=relaxed/simple; bh=bKBoSGPBXAK9sMrL73YdzSJoRutDs6D6S/11XKzTJps=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jggyhP7yctehyM9U375GSu6iStMuCjNUpyQFFDxKz2c7Aeyr5uh2QCYcFz47GJLcp/9gGwL8NwScpIe3jQJMJ7XB0O5maPEIhTUU2m8RcWXsUo1+5hIIXId0hKIUFyfntzrOpPboAWI1njAlLQOmwOlLpkGo3H5Uf+CjIXK1kxM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=xWqTh0H6; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="xWqTh0H6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 533EFC4CEF1; Mon, 1 Dec 2025 11:33:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1764588833; bh=bKBoSGPBXAK9sMrL73YdzSJoRutDs6D6S/11XKzTJps=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xWqTh0H6yQhbo7s5sLe9dDtQwr/o7vEF+OuYKC72ER/eyB9b3m2PQFWPWguPuBjEY dh9lcvQTvni7MUsu35rdbxCw43SulSS4lf+xaMc5ywT6iYoHSQcIg39KyYUnWdolPf yUZKDOcOG2HxL4rXhPaOfe0WJ26cCXbEVUNXooGc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Peter Xu , Mike Kravetz , James Houghton , Andrea Arcangeli , Axel Rasmussen , David Hildenbrand , Muchun Song , Nadav Amit , Andrew Morton , Harry Yoo Subject: [PATCH 5.4 186/187] mm/mprotect: use long for page accountings and retval Date: Mon, 1 Dec 2025 12:24:54 +0100 Message-ID: <20251201112247.932486770@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251201112241.242614045@linuxfoundation.org> References: <20251201112241.242614045@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Peter Xu commit a79390f5d6a78647fd70856bd42b22d994de0ba2 upstream. Switch to use type "long" for page accountings and retval across the whole procedure of change_protection(). The change should have shrinked the possible maximum page number to be half comparing to previous (ULONG_MAX / 2), but it shouldn't overflow on any system either because the maximum possible pages touched by change protection should be ULONG_MAX / PAGE_SIZE. Two reasons to switch from "unsigned long" to "long": 1. It suites better on count_vm_numa_events(), whose 2nd parameter takes a long type. 2. It paves way for returning negative (error) values in the future. Currently the only caller that consumes this retval is change_prot_numa(), where the unsigned long was converted to an int. Since at it, touching up the numa code to also take a long, so it'll avoid any possible overflow too during the int-size convertion. Link: https://lkml.kernel.org/r/20230104225207.1066932-3-peterx@redhat.com Signed-off-by: Peter Xu Acked-by: Mike Kravetz Acked-by: James Houghton Cc: Andrea Arcangeli Cc: Axel Rasmussen Cc: David Hildenbrand Cc: Muchun Song Cc: Nadav Amit Signed-off-by: Andrew Morton [ Adjust context ] Signed-off-by: Harry Yoo Signed-off-by: Greg Kroah-Hartman --- include/linux/hugetlb.h | 4 ++-- include/linux/mm.h | 2 +- mm/hugetlb.c | 4 ++-- mm/mempolicy.c | 2 +- mm/mprotect.c | 26 +++++++++++++------------- 5 files changed, 19 insertions(+), 19 deletions(-) --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -137,7 +137,7 @@ struct page *follow_huge_pgd(struct mm_s int pmd_huge(pmd_t pmd); int pud_huge(pud_t pud); -unsigned long hugetlb_change_protection(struct vm_area_struct *vma, +long hugetlb_change_protection(struct vm_area_struct *vma, unsigned long address, unsigned long end, pgprot_t newprot); bool is_hugetlb_entry_migration(pte_t pte); @@ -195,7 +195,7 @@ static inline bool isolate_huge_page(str #define putback_active_hugepage(p) do {} while (0) #define move_hugetlb_state(old, new, reason) do {} while (0) -static inline unsigned long hugetlb_change_protection(struct vm_area_struct *vma, +static inline long hugetlb_change_protection(struct vm_area_struct *vma, unsigned long address, unsigned long end, pgprot_t newprot) { return 0; --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1657,7 +1657,7 @@ extern unsigned long move_page_tables(st unsigned long old_addr, struct vm_area_struct *new_vma, unsigned long new_addr, unsigned long len, bool need_rmap_locks); -extern unsigned long change_protection(struct vm_area_struct *vma, unsigned long start, +extern long change_protection(struct vm_area_struct *vma, unsigned long start, unsigned long end, pgprot_t newprot, int dirty_accountable, int prot_numa); extern int mprotect_fixup(struct vm_area_struct *vma, --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -4635,7 +4635,7 @@ same_page: #define flush_hugetlb_tlb_range(vma, addr, end) flush_tlb_range(vma, addr, end) #endif -unsigned long hugetlb_change_protection(struct vm_area_struct *vma, +long hugetlb_change_protection(struct vm_area_struct *vma, unsigned long address, unsigned long end, pgprot_t newprot) { struct mm_struct *mm = vma->vm_mm; @@ -4643,7 +4643,7 @@ unsigned long hugetlb_change_protection( pte_t *ptep; pte_t pte; struct hstate *h = hstate_vma(vma); - unsigned long pages = 0; + long pages = 0; bool shared_pmd = false; struct mmu_notifier_range range; --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -595,7 +595,7 @@ unlock: unsigned long change_prot_numa(struct vm_area_struct *vma, unsigned long addr, unsigned long end) { - int nr_updated; + long nr_updated; nr_updated = change_protection(vma, addr, end, PAGE_NONE, 0, 1); if (nr_updated) --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -35,13 +35,13 @@ #include "internal.h" -static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, +static long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr, unsigned long end, pgprot_t newprot, int dirty_accountable, int prot_numa) { pte_t *pte, oldpte; spinlock_t *ptl; - unsigned long pages = 0; + long pages = 0; int target_node = NUMA_NO_NODE; /* @@ -186,13 +186,13 @@ static inline int pmd_none_or_clear_bad_ return 0; } -static inline unsigned long change_pmd_range(struct vm_area_struct *vma, +static inline long change_pmd_range(struct vm_area_struct *vma, pud_t *pud, unsigned long addr, unsigned long end, pgprot_t newprot, int dirty_accountable, int prot_numa) { pmd_t *pmd; unsigned long next; - unsigned long pages = 0; + long pages = 0; unsigned long nr_huge_updates = 0; struct mmu_notifier_range range; @@ -200,7 +200,7 @@ static inline unsigned long change_pmd_r pmd = pmd_offset(pud, addr); do { - unsigned long this_pages; + long this_pages; next = pmd_addr_end(addr, end); @@ -258,13 +258,13 @@ next: return pages; } -static inline unsigned long change_pud_range(struct vm_area_struct *vma, +static inline long change_pud_range(struct vm_area_struct *vma, p4d_t *p4d, unsigned long addr, unsigned long end, pgprot_t newprot, int dirty_accountable, int prot_numa) { pud_t *pud; unsigned long next; - unsigned long pages = 0; + long pages = 0; pud = pud_offset(p4d, addr); do { @@ -278,13 +278,13 @@ static inline unsigned long change_pud_r return pages; } -static inline unsigned long change_p4d_range(struct vm_area_struct *vma, +static inline long change_p4d_range(struct vm_area_struct *vma, pgd_t *pgd, unsigned long addr, unsigned long end, pgprot_t newprot, int dirty_accountable, int prot_numa) { p4d_t *p4d; unsigned long next; - unsigned long pages = 0; + long pages = 0; p4d = p4d_offset(pgd, addr); do { @@ -298,7 +298,7 @@ static inline unsigned long change_p4d_r return pages; } -static unsigned long change_protection_range(struct vm_area_struct *vma, +static long change_protection_range(struct vm_area_struct *vma, unsigned long addr, unsigned long end, pgprot_t newprot, int dirty_accountable, int prot_numa) { @@ -306,7 +306,7 @@ static unsigned long change_protection_r pgd_t *pgd; unsigned long next; unsigned long start = addr; - unsigned long pages = 0; + long pages = 0; BUG_ON(addr >= end); pgd = pgd_offset(mm, addr); @@ -328,11 +328,11 @@ static unsigned long change_protection_r return pages; } -unsigned long change_protection(struct vm_area_struct *vma, unsigned long start, +long change_protection(struct vm_area_struct *vma, unsigned long start, unsigned long end, pgprot_t newprot, int dirty_accountable, int prot_numa) { - unsigned long pages; + long pages; if (is_vm_hugetlb_page(vma)) pages = hugetlb_change_protection(vma, start, end, newprot);