From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 46EDF3CB55A; Sun, 23 Aug 2026 11:47:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787485634; cv=none; b=sGQ9Sh1J1nPBO4RTvM6Nm0Fge51xBelbHFxkGxBSryPHH0me3NBx5Rom7AtNOoVeO/wbIrA6U6MRCoBdzNqQHQPQ0jyCPFg9cf1/lbEXfkgduHH+Ir1rl2wvXFcngYdd0kvXr0kbUkWEFejWOyQi9T5EhxSyC41Nxndfg30eMY0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787485634; c=relaxed/simple; bh=q3A23n1w2OG/lXXU9CfkkQZfQRejkQM/lQ5Dh1nUPzQ=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=P2RlmZeX4/u0GntvlHS8gFxQ3FI2Y7yLvHLDj8/osqAIpUwRrNW04n5SqtVV62ciLIprHTbdfqduajGmDv9IYeor0silQ2XzKcpmIlg9/UElYdWUslVXyATlKHrCQvyJKJmXeUfUBH8gJWKFQD/C6x86FRDn8gpaf4YvK591TMA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=H+w987WX; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="H+w987WX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6FC6E1F00A3A; Sun, 23 Aug 2026 11:47:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787485632; bh=VP6xAszPN9d5Ab+tWR5O9C7cLz2aPGLpAHH/Gr7UO8o=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=H+w987WXJaPHn2bT6gKuUd72cuh1y13kfP506djkCA0zXRW/jORubuL195QaKVqmG KuCmgCTHchPs/NniDr3HKwZqjXGQs3pex3kFQlGOv8/qmIVpaZRNERU7Dq5clxtTL1 g55BGIwhPam9+5AxnN7wlrCC/hP1Zp4Tw77b4/3dE1OxfgpIsQHjcEK9GPfawCOMs6 qwH2PXIXAxF94xauBdmZSyzpxHD+65Ap0G9d9F2i4cHYgdYz/i94AWYtOwIQxroq4d id+esyyJnOy+p55d3eNo+FGuBcxpb+1iG6SOZe/vDkAASWckBuVJabv9IoLRGgBvwy zoNlMXUs2wT7Q== From: "Mike Rapoport (Microsoft)" Date: Sun, 23 Aug 2026 14:46:16 +0300 Subject: [PATCH v2 5/6] mm/execmem: use VM_FLUSH_RESET_PERMS for ROX cache allocations Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260823-execmem-set-vm-perms-v0-2-v2-5-b013a37d84b3@kernel.org> References: <20260823-execmem-set-vm-perms-v0-2-v2-0-b013a37d84b3@kernel.org> In-Reply-To: <20260823-execmem-set-vm-perms-v0-2-v2-0-b013a37d84b3@kernel.org> To: Andrew Morton Cc: =?utf-8?q?Adrian_Barna=C5=9B?= , Albert Ou , Alexander Gordeev , Alexandre Ghiti , Andy Lutomirski , Borislav Petkov , Brendan Jackman , Catalin Marinas , Christian Borntraeger , Dave Hansen , David Hildenbrand , Gerald Schaefer , Heiko Carstens , Huacai Chen , Ingo Molnar , Len Brown , Mike Rapoport , Palmer Dabbelt , Paul Walmsley , Pavel Machek , Peter Zijlstra , "H. Peter Anvin" , "Rafael J. Wysocki" , Ryan Roberts , Sven Schnelle , Thomas Gleixner , Uladzislau Rezki , Vasily Gorbik , WANG Xuerui , Will Deacon , x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-pm@vger.kernel.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, loongarch@lists.linux.dev X-Mailer: b4 0.17-dev Initially execmem completely removed direct map alias for the memory allocated for the ROX cache in PMD_SIZE chunks. When that memory was freed, its direct map was restored also in PMD_SIZE chunks to avoid fragmentation of the direct map caused by vmalloc::vm_reset_perms(). This required execmem to implement the wrappers for set_direct_map APIs for proper sequencing of removal and restoration of the direct map aliases. Since then x86's CPA gained support for collapsing the direct map page tables for ROX pages and execmem switched from removing ROX caches from the direct map to making them ROX there, so execmem only needs to update direct map alias permissions when freeing the ROX cache memory. vmalloc already handles those updates for areas with VM_FLUSH_RESET_PERMS set and vmalloc::vm_reset_perms() does not force split of the direct map for PMD_SIZE chunks. Make all execmem vmalloc allocations use VM_FLUSH_RESET_PERMS and remove custom wrappers for set_direct_map APIs. Signed-off-by: Mike Rapoport (Microsoft) --- mm/execmem.c | 42 +++++++----------------------------------- 1 file changed, 7 insertions(+), 35 deletions(-) diff --git a/mm/execmem.c b/mm/execmem.c index 74a178a87e75..d35f1d0ea54a 100644 --- a/mm/execmem.c +++ b/mm/execmem.c @@ -36,6 +36,7 @@ static void *execmem_vmalloc(struct execmem_range *range, size_t size, unsigned long end = range->end; void *p; + vm_flags |= VM_FLUSH_RESET_PERMS; if (kasan) vm_flags |= VM_DEFER_KMEMLEAK; @@ -113,28 +114,6 @@ static inline unsigned long mas_range_len(struct ma_state *mas) return mas->last - mas->index + 1; } -static int execmem_set_direct_map_valid(struct vm_struct *vm, bool valid) -{ - unsigned int nr = (1 << get_vm_area_page_order(vm)); - unsigned int updated = 0; - int err = 0; - - for (int i = 0; i < vm->nr_pages; i += nr) { - err = set_direct_map_valid_noflush(vm->pages[i], nr, valid); - if (err) - goto err_restore; - updated += nr; - } - - return 0; - -err_restore: - for (int i = 0; i < updated; i += nr) - set_direct_map_valid_noflush(vm->pages[i], nr, !valid); - - return err; -} - static int execmem_force_rw(void *ptr, size_t size) { unsigned int nr = PAGE_ALIGN(size) >> PAGE_SHIFT; @@ -169,9 +148,6 @@ static void execmem_cache_clean(struct work_struct *work) if (IS_ALIGNED(size, PMD_SIZE) && IS_ALIGNED(mas.index, PMD_SIZE)) { - struct vm_struct *vm = find_vm_area(area); - - execmem_set_direct_map_valid(vm, true); mas_store_gfp(&mas, NULL, GFP_KERNEL); vfree(area); } @@ -312,18 +288,15 @@ static void *execmem_cache_populate_alloc(struct execmem_range *range, size_t si */ mutex_lock(mutex); err = execmem_cache_add_locked(p, alloc_size, GFP_KERNEL); - if (err) - goto err_reset_direct_map; - - p = execmem_cache_alloc_locked(range, size); - + if (!err) + p = execmem_cache_alloc_locked(range, size); mutex_unlock(mutex); + if (err) + goto err_free_mem; + return p; -err_reset_direct_map: - mutex_unlock(mutex); - execmem_set_direct_map_valid(vm, true); err_free_mem: vfree(p); return NULL; @@ -466,7 +439,6 @@ void *execmem_alloc(enum execmem_type type, size_t size) { struct execmem_range *range = &execmem_info->ranges[type]; bool use_cache = range->flags & EXECMEM_ROX_CACHE; - unsigned long vm_flags = VM_FLUSH_RESET_PERMS; pgprot_t pgprot = range->pgprot; void *p = NULL; @@ -475,7 +447,7 @@ void *execmem_alloc(enum execmem_type type, size_t size) if (use_cache) p = execmem_cache_alloc(range, size); else - p = execmem_vmalloc(range, size, pgprot, vm_flags); + p = execmem_vmalloc(range, size, pgprot, 0); return kasan_reset_tag(p); } -- 2.53.0