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 82B567FBD2 for ; Fri, 26 Apr 2024 04:01:25 +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=1714104085; cv=none; b=cYZCs7icEtO//TdlKY0FpmYiC1RbAr9jciBE3ZU5TVVMwS0MXB8DfQ5oEljEbFt3Xt7/DbXbUDfOm7y6gHggIXkkDwlN+jUhi7x/4E6UuK6RMDxmddsF16Z2uKs7IFlXFzSotdBoAzqvPQD0iaDTn5dTUq8qwuPLOsr7AEhbs+8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714104085; c=relaxed/simple; bh=UpRxr8idhzXuZNY4Ew+7RXDEEPiNHgoYzjgXIChnaNc=; h=Date:To:From:Subject:Message-Id; b=pEOkHMWUETPNjU5ZmRaMK1WnXrRCGISYP1Z7AM/qN4XSJsTgJfmmOmguka7jsDeER0fVWuN+HXNx5fL6+n5Gsf2hxRvay6lFxkH5qlYtGclk/WI9IOFUFX8eqeSueqMIB03c297I+BT7QUOD/+gC6BN1mmwXvQpvj1TMm6d4kiI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=KbpM06EM; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="KbpM06EM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 58D1FC113CD; Fri, 26 Apr 2024 04:01:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1714104085; bh=UpRxr8idhzXuZNY4Ew+7RXDEEPiNHgoYzjgXIChnaNc=; h=Date:To:From:Subject:From; b=KbpM06EMTX1ybgEFw7ncEZXy0GHOPmwRtU3+Kn/G/TqYRHL9e0euW1dsyYyAnsocR yQmE2o55Kc2U5Bsca6dmRHJmW9gDr/AGekKJyO95o8yTaTtxnMYe9p+2fQgiyKsvwB AzPIN4WNorFi2t9faaIqmOV0yHZnk5GbEoQrynMg= Date: Thu, 25 Apr 2024 21:01:24 -0700 To: mm-commits@vger.kernel.org,tglx@linutronix.de,peterz@infradead.org,npiggin@gmail.com,naveen.n.rao@linux.ibm.com,mpe@ellerman.id.au,mingo@redhat.com,luto@kernel.org,Liam.Howlett@oracle.com,kirill.shutemov@linux.intel.com,keescook@chromium.org,James.Bottomley@HansenPartnership.com,hpa@zytor.com,guoren@kernel.org,deller@gmx.de,debug@rivosinc.com,dave.hansen@linux.intel.com,dan.j.williams@intel.com,christophe.leroy@csgroup.eu,broonie@kernel.org,bp@alien8.de,ast@kernel.org,aneesh.kumar@kernel.org,rick.p.edgecombe@intel.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] mm-use-get_unmapped_area_vmflags.patch removed from -mm tree Message-Id: <20240426040125.58D1FC113CD@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm: use get_unmapped_area_vmflags() has been removed from the -mm tree. Its filename was mm-use-get_unmapped_area_vmflags.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Rick Edgecombe Subject: mm: use get_unmapped_area_vmflags() Date: Mon, 25 Mar 2024 19:16:47 -0700 When memory is being placed, mmap() will take care to respect the guard gaps of certain types of memory (VM_SHADOWSTACK, VM_GROWSUP and VM_GROWSDOWN). In order to ensure guard gaps between mappings, mmap() needs to consider two things: 1. That the new mapping isn't placed in an any existing mappings guard gaps. 2. That the new mapping isn't placed such that any existing mappings are not in *its* guard gaps. The long standing behavior of mmap() is to ensure 1, but not take any care around 2. So for example, if there is a PAGE_SIZE free area, and a mmap() with a PAGE_SIZE size, and a type that has a guard gap is being placed, mmap() may place the shadow stack in the PAGE_SIZE free area. Then the mapping that is supposed to have a guard gap will not have a gap to the adjacent VMA. Use mm_get_unmapped_area_vmflags() in the do_mmap() so future changes can cause shadow stack mappings to be placed with a guard gap. Also use the THP variant that takes vm_flags, such that THP shadow stack can get the same treatment. Adjust the vm_flags calculation to happen earlier so that the vm_flags can be passed into __get_unmapped_area(). Link: https://lkml.kernel.org/r/20240326021656.202649-6-rick.p.edgecombe@intel.com Signed-off-by: Rick Edgecombe Reviewed-by: Christophe Leroy Cc: Alexei Starovoitov Cc: Andy Lutomirski Cc: Aneesh Kumar K.V Cc: Borislav Petkov (AMD) Cc: Dan Williams Cc: Dave Hansen Cc: Deepak Gupta Cc: Guo Ren Cc: Helge Deller Cc: H. Peter Anvin (Intel) Cc: Ingo Molnar Cc: "James E.J. Bottomley" Cc: Kees Cook Cc: Kirill A. Shutemov Cc: Liam R. Howlett Cc: Mark Brown Cc: Michael Ellerman Cc: Naveen N. Rao Cc: Nicholas Piggin Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Andrew Morton --- include/linux/mm.h | 11 ++++++++++- mm/mmap.c | 32 ++++++++++++++++---------------- 2 files changed, 26 insertions(+), 17 deletions(-) --- a/include/linux/mm.h~mm-use-get_unmapped_area_vmflags +++ a/include/linux/mm.h @@ -3413,7 +3413,16 @@ extern int install_special_mapping(struc unsigned long randomize_stack_top(unsigned long stack_top); unsigned long randomize_page(unsigned long start, unsigned long range); -extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long); +unsigned long +__get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, + unsigned long pgoff, unsigned long flags, vm_flags_t vm_flags); + +static inline unsigned long +get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, + unsigned long pgoff, unsigned long flags) +{ + return __get_unmapped_area(file, addr, len, pgoff, flags, 0); +} extern unsigned long mmap_region(struct file *file, unsigned long addr, unsigned long len, vm_flags_t vm_flags, unsigned long pgoff, --- a/mm/mmap.c~mm-use-get_unmapped_area_vmflags +++ a/mm/mmap.c @@ -1255,18 +1255,6 @@ unsigned long do_mmap(struct file *file, if (mm->map_count > sysctl_max_map_count) return -ENOMEM; - /* Obtain the address to map to. we verify (or select) it and ensure - * that it represents a valid section of the address space. - */ - addr = get_unmapped_area(file, addr, len, pgoff, flags); - if (IS_ERR_VALUE(addr)) - return addr; - - if (flags & MAP_FIXED_NOREPLACE) { - if (find_vma_intersection(mm, addr, addr + len)) - return -EEXIST; - } - if (prot == PROT_EXEC) { pkey = execute_only_pkey(mm); if (pkey < 0) @@ -1280,6 +1268,18 @@ unsigned long do_mmap(struct file *file, vm_flags |= calc_vm_prot_bits(prot, pkey) | calc_vm_flag_bits(flags) | mm->def_flags | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; + /* Obtain the address to map to. we verify (or select) it and ensure + * that it represents a valid section of the address space. + */ + addr = __get_unmapped_area(file, addr, len, pgoff, flags, vm_flags); + if (IS_ERR_VALUE(addr)) + return addr; + + if (flags & MAP_FIXED_NOREPLACE) { + if (find_vma_intersection(mm, addr, addr + len)) + return -EEXIST; + } + if (flags & MAP_LOCKED) if (!can_do_mlock()) return -EPERM; @@ -1836,8 +1836,8 @@ unsigned long mm_get_unmapped_area_vmfla } unsigned long -get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, - unsigned long pgoff, unsigned long flags) +__get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, + unsigned long pgoff, unsigned long flags, vm_flags_t vm_flags) { unsigned long (*get_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long) @@ -1872,8 +1872,8 @@ get_unmapped_area(struct file *file, uns if (get_area) addr = get_area(file, addr, len, pgoff, flags); else - addr = mm_get_unmapped_area(current->mm, file, addr, len, - pgoff, flags); + addr = mm_get_unmapped_area_vmflags(current->mm, file, addr, len, + pgoff, flags, vm_flags); if (IS_ERR_VALUE(addr)) return addr; _ Patches currently in -mm which might be from rick.p.edgecombe@intel.com are