| Message ID | aaf0c0969d46b2feb9017f3e1b3ef3970b633d91.1563904656.git.andreyknvl@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: untag user pointers passed to the kernel | expand |
On Tue, Jul 23, 2019 at 07:58:41PM +0200, Andrey Konovalov wrote: > This patch is a part of a series that extends kernel ABI to allow to pass > tagged user pointers (with the top byte set to something else other than > 0x00) as syscall arguments. > > This patch allows tagged pointers to be passed to the following memory > syscalls: get_mempolicy, madvise, mbind, mincore, mlock, mlock2, mprotect, > mremap, msync, munlock, move_pages. > > The mmap and mremap syscalls do not currently accept tagged addresses. > Architectures may interpret the tag as a background colour for the > corresponding vma. > > Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com> > Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> > Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> > Reviewed-by: Kees Cook <keescook@chromium.org> > Signed-off-by: Andrey Konovalov <andreyknvl@google.com> > --- > mm/madvise.c | 2 ++ > mm/mempolicy.c | 3 +++ > mm/migrate.c | 2 +- > mm/mincore.c | 2 ++ > mm/mlock.c | 4 ++++ > mm/mprotect.c | 2 ++ > mm/mremap.c | 7 +++++++ > mm/msync.c | 2 ++ > 8 files changed, 23 insertions(+), 1 deletion(-) More back and forth discussions on how to specify the exceptions here. I'm proposing just dropping the exceptions and folding in the diff below. Andrew, if you prefer a standalone patch instead, please let me know: ------------------8<---------------------------- From 9a5286acaa638c6a917d96986bf28dad35e24a0c Mon Sep 17 00:00:00 2001 From: Catalin Marinas <catalin.marinas@arm.com> Date: Fri, 9 Aug 2019 14:21:33 +0100 Subject: [PATCH] fixup! mm: untag user pointers passed to memory syscalls mmap, mremap, munmap, brk added to the list of syscalls that accept tagged pointers. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> --- mm/mmap.c | 5 +++++ mm/mremap.c | 6 +----- 2 files changed, 6 insertions(+), 5 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index 7e8c3e8ae75f..b766b633b7ae 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -201,6 +201,8 @@ SYSCALL_DEFINE1(brk, unsigned long, brk) bool downgraded = false; LIST_HEAD(uf); + brk = untagged_addr(brk); + if (down_write_killable(&mm->mmap_sem)) return -EINTR; @@ -1573,6 +1575,8 @@ unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len, struct file *file = NULL; unsigned long retval; + addr = untagged_addr(addr); + if (!(flags & MAP_ANONYMOUS)) { audit_mmap_fd(fd, flags); file = fget(fd); @@ -2874,6 +2878,7 @@ EXPORT_SYMBOL(vm_munmap); SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len) { + addr = untagged_addr(addr); profile_munmap(addr); return __vm_munmap(addr, len, true); } diff --git a/mm/mremap.c b/mm/mremap.c index 64c9a3b8be0a..1fc8a29fbe3f 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -606,12 +606,8 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, LIST_HEAD(uf_unmap_early); LIST_HEAD(uf_unmap); - /* - * Architectures may interpret the tag passed to mmap as a background - * colour for the corresponding vma. For mremap we don't allow tagged - * new_addr to preserve similar behaviour to mmap. - */ addr = untagged_addr(addr); + new_addr = untagged_addr(new_addr); if (flags & ~(MREMAP_FIXED | MREMAP_MAYMOVE)) return ret;
diff --git a/mm/madvise.c b/mm/madvise.c index 968df3aa069f..4b102a61bfbf 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -810,6 +810,8 @@ SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior) size_t len; struct blk_plug plug; + start = untagged_addr(start); + if (!madvise_behavior_valid(behavior)) return error; diff --git a/mm/mempolicy.c b/mm/mempolicy.c index f48693f75b37..74c134d0c84e 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1360,6 +1360,7 @@ static long kernel_mbind(unsigned long start, unsigned long len, int err; unsigned short mode_flags; + start = untagged_addr(start); mode_flags = mode & MPOL_MODE_FLAGS; mode &= ~MPOL_MODE_FLAGS; if (mode >= MPOL_MAX) @@ -1517,6 +1518,8 @@ static int kernel_get_mempolicy(int __user *policy, int uninitialized_var(pval); nodemask_t nodes; + addr = untagged_addr(addr); + if (nmask != NULL && maxnode < nr_node_ids) return -EINVAL; diff --git a/mm/migrate.c b/mm/migrate.c index 8992741f10aa..8f59c24cb141 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1609,7 +1609,7 @@ static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes, goto out_flush; if (get_user(node, nodes + i)) goto out_flush; - addr = (unsigned long)p; + addr = (unsigned long)untagged_addr(p); err = -ENODEV; if (node < 0 || node >= MAX_NUMNODES) diff --git a/mm/mincore.c b/mm/mincore.c index 4fe91d497436..3cfa120ba0eb 100644 --- a/mm/mincore.c +++ b/mm/mincore.c @@ -257,6 +257,8 @@ SYSCALL_DEFINE3(mincore, unsigned long, start, size_t, len, unsigned long pages; unsigned char *tmp; + start = untagged_addr(start); + /* Check the start address: needs to be page-aligned.. */ if (start & ~PAGE_MASK) return -EINVAL; diff --git a/mm/mlock.c b/mm/mlock.c index a90099da4fb4..a72c1eeded77 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -674,6 +674,8 @@ static __must_check int do_mlock(unsigned long start, size_t len, vm_flags_t fla unsigned long lock_limit; int error = -ENOMEM; + start = untagged_addr(start); + if (!can_do_mlock()) return -EPERM; @@ -735,6 +737,8 @@ SYSCALL_DEFINE2(munlock, unsigned long, start, size_t, len) { int ret; + start = untagged_addr(start); + len = PAGE_ALIGN(len + (offset_in_page(start))); start &= PAGE_MASK; diff --git a/mm/mprotect.c b/mm/mprotect.c index bf38dfbbb4b4..19f981b733bc 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -465,6 +465,8 @@ static int do_mprotect_pkey(unsigned long start, size_t len, const bool rier = (current->personality & READ_IMPLIES_EXEC) && (prot & PROT_READ); + start = untagged_addr(start); + prot &= ~(PROT_GROWSDOWN|PROT_GROWSUP); if (grows == (PROT_GROWSDOWN|PROT_GROWSUP)) /* can't be both */ return -EINVAL; diff --git a/mm/mremap.c b/mm/mremap.c index fc241d23cd97..64c9a3b8be0a 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -606,6 +606,13 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, LIST_HEAD(uf_unmap_early); LIST_HEAD(uf_unmap); + /* + * Architectures may interpret the tag passed to mmap as a background + * colour for the corresponding vma. For mremap we don't allow tagged + * new_addr to preserve similar behaviour to mmap. + */ + addr = untagged_addr(addr); + if (flags & ~(MREMAP_FIXED | MREMAP_MAYMOVE)) return ret; diff --git a/mm/msync.c b/mm/msync.c index ef30a429623a..c3bd3e75f687 100644 --- a/mm/msync.c +++ b/mm/msync.c @@ -37,6 +37,8 @@ SYSCALL_DEFINE3(msync, unsigned long, start, size_t, len, int, flags) int unmapped_error = 0; int error = -EINVAL; + start = untagged_addr(start); + if (flags & ~(MS_ASYNC | MS_INVALIDATE | MS_SYNC)) goto out; if (offset_in_page(start))