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Commit 690c4ca8 authored by Andrey Konovalov's avatar Andrey Konovalov Committed by Alistair Delva
Browse files

UPSTREAM: mm: untag user pointers passed to memory syscalls 

(Upstream commit 057d3389108eda8a20c7f496f011846932680d88).

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.

Link: http://lkml.kernel.org/r/aaf0c0969d46b2feb9017f3e1b3ef3970b633d91.1563904656.git.andreyknvl@google.com


Signed-off-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Reviewed-by: default avatarKhalid Aziz <khalid.aziz@oracle.com>
Reviewed-by: default avatarVincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Jens Wiklander <jens.wiklander@linaro.org>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Bug: 135692346
Change-Id: I1a2d89eedb45e618e85ca515f4c9121460711efb
parent f0526f40

mm/madvise.c

+2 −0
Original line number Diff line number Diff line
@@ -808,6 +808,8 @@ 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;

mm/mempolicy.c

+3 −0
Original line number Diff line number Diff line
@@ -1393,6 +1393,7 @@ 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)
@@ -1550,6 +1551,8 @@ 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;

mm/migrate.c

+1 −1
Original line number Diff line number Diff line
@@ -1606,7 +1606,7 @@ 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)

mm/mincore.c

+2 −0
Original line number Diff line number Diff line
@@ -249,6 +249,8 @@ 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;

mm/mlock.c

+4 −0
Original line number Diff line number Diff line
@@ -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;