diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-03-20 19:08:56 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-03-20 19:08:56 -0700 |
commit | 643ad15d47410d37d43daf3ef1c8ac52c281efa5 (patch) | |
tree | a864860cfe04c994c03d7946e12b3351e38a168b /drivers/infiniband | |
parent | 24b5e20f11a75866bbffc46c30a22fa50612a769 (diff) | |
parent | 0d47638f80a02b15869f1fe1fc09e5bf996750fd (diff) |
Merge branch 'mm-pkeys-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 protection key support from Ingo Molnar:
"This tree adds support for a new memory protection hardware feature
that is available in upcoming Intel CPUs: 'protection keys' (pkeys).
There's a background article at LWN.net:
https://lwn.net/Articles/643797/
The gist is that protection keys allow the encoding of
user-controllable permission masks in the pte. So instead of having a
fixed protection mask in the pte (which needs a system call to change
and works on a per page basis), the user can map a (handful of)
protection mask variants and can change the masks runtime relatively
cheaply, without having to change every single page in the affected
virtual memory range.
This allows the dynamic switching of the protection bits of large
amounts of virtual memory, via user-space instructions. It also
allows more precise control of MMU permission bits: for example the
executable bit is separate from the read bit (see more about that
below).
This tree adds the MM infrastructure and low level x86 glue needed for
that, plus it adds a high level API to make use of protection keys -
if a user-space application calls:
mmap(..., PROT_EXEC);
or
mprotect(ptr, sz, PROT_EXEC);
(note PROT_EXEC-only, without PROT_READ/WRITE), the kernel will notice
this special case, and will set a special protection key on this
memory range. It also sets the appropriate bits in the Protection
Keys User Rights (PKRU) register so that the memory becomes unreadable
and unwritable.
So using protection keys the kernel is able to implement 'true'
PROT_EXEC on x86 CPUs: without protection keys PROT_EXEC implies
PROT_READ as well. Unreadable executable mappings have security
advantages: they cannot be read via information leaks to figure out
ASLR details, nor can they be scanned for ROP gadgets - and they
cannot be used by exploits for data purposes either.
We know about no user-space code that relies on pure PROT_EXEC
mappings today, but binary loaders could start making use of this new
feature to map binaries and libraries in a more secure fashion.
There is other pending pkeys work that offers more high level system
call APIs to manage protection keys - but those are not part of this
pull request.
Right now there's a Kconfig that controls this feature
(CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS) that is default enabled
(like most x86 CPU feature enablement code that has no runtime
overhead), but it's not user-configurable at the moment. If there's
any serious problem with this then we can make it configurable and/or
flip the default"
* 'mm-pkeys-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (38 commits)
x86/mm/pkeys: Fix mismerge of protection keys CPUID bits
mm/pkeys: Fix siginfo ABI breakage caused by new u64 field
x86/mm/pkeys: Fix access_error() denial of writes to write-only VMA
mm/core, x86/mm/pkeys: Add execute-only protection keys support
x86/mm/pkeys: Create an x86 arch_calc_vm_prot_bits() for VMA flags
x86/mm/pkeys: Allow kernel to modify user pkey rights register
x86/fpu: Allow setting of XSAVE state
x86/mm: Factor out LDT init from context init
mm/core, x86/mm/pkeys: Add arch_validate_pkey()
mm/core, arch, powerpc: Pass a protection key in to calc_vm_flag_bits()
x86/mm/pkeys: Actually enable Memory Protection Keys in the CPU
x86/mm/pkeys: Add Kconfig prompt to existing config option
x86/mm/pkeys: Dump pkey from VMA in /proc/pid/smaps
x86/mm/pkeys: Dump PKRU with other kernel registers
mm/core, x86/mm/pkeys: Differentiate instruction fetches
x86/mm/pkeys: Optimize fault handling in access_error()
mm/core: Do not enforce PKEY permissions on remote mm access
um, pkeys: Add UML arch_*_access_permitted() methods
mm/gup, x86/mm/pkeys: Check VMAs and PTEs for protection keys
x86/mm/gup: Simplify get_user_pages() PTE bit handling
...
Diffstat (limited to 'drivers/infiniband')
-rw-r--r-- | drivers/infiniband/core/umem.c | 2 | ||||
-rw-r--r-- | drivers/infiniband/core/umem_odp.c | 8 | ||||
-rw-r--r-- | drivers/infiniband/hw/mthca/mthca_memfree.c | 3 | ||||
-rw-r--r-- | drivers/infiniband/hw/qib/qib_user_pages.c | 3 | ||||
-rw-r--r-- | drivers/infiniband/hw/usnic/usnic_uiom.c | 2 |
5 files changed, 8 insertions, 10 deletions
diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index 38acb3cfc545..fe4d2e1a8b58 100644 --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -188,7 +188,7 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr, sg_list_start = umem->sg_head.sgl; while (npages) { - ret = get_user_pages(current, current->mm, cur_base, + ret = get_user_pages(cur_base, min_t(unsigned long, npages, PAGE_SIZE / sizeof (struct page *)), 1, !umem->writable, page_list, vma_list); diff --git a/drivers/infiniband/core/umem_odp.c b/drivers/infiniband/core/umem_odp.c index e69bf266049d..75077a018675 100644 --- a/drivers/infiniband/core/umem_odp.c +++ b/drivers/infiniband/core/umem_odp.c @@ -572,10 +572,10 @@ int ib_umem_odp_map_dma_pages(struct ib_umem *umem, u64 user_virt, u64 bcnt, * complex (and doesn't gain us much performance in most use * cases). */ - npages = get_user_pages(owning_process, owning_mm, user_virt, - gup_num_pages, - access_mask & ODP_WRITE_ALLOWED_BIT, 0, - local_page_list, NULL); + npages = get_user_pages_remote(owning_process, owning_mm, + user_virt, gup_num_pages, + access_mask & ODP_WRITE_ALLOWED_BIT, + 0, local_page_list, NULL); up_read(&owning_mm->mmap_sem); if (npages < 0) diff --git a/drivers/infiniband/hw/mthca/mthca_memfree.c b/drivers/infiniband/hw/mthca/mthca_memfree.c index 7d2e42dd6926..6c00d04b8b28 100644 --- a/drivers/infiniband/hw/mthca/mthca_memfree.c +++ b/drivers/infiniband/hw/mthca/mthca_memfree.c @@ -472,8 +472,7 @@ int mthca_map_user_db(struct mthca_dev *dev, struct mthca_uar *uar, goto out; } - ret = get_user_pages(current, current->mm, uaddr & PAGE_MASK, 1, 1, 0, - pages, NULL); + ret = get_user_pages(uaddr & PAGE_MASK, 1, 1, 0, pages, NULL); if (ret < 0) goto out; diff --git a/drivers/infiniband/hw/qib/qib_user_pages.c b/drivers/infiniband/hw/qib/qib_user_pages.c index 74f90b2619f6..2d2b94fd3633 100644 --- a/drivers/infiniband/hw/qib/qib_user_pages.c +++ b/drivers/infiniband/hw/qib/qib_user_pages.c @@ -66,8 +66,7 @@ static int __qib_get_user_pages(unsigned long start_page, size_t num_pages, } for (got = 0; got < num_pages; got += ret) { - ret = get_user_pages(current, current->mm, - start_page + got * PAGE_SIZE, + ret = get_user_pages(start_page + got * PAGE_SIZE, num_pages - got, 1, 1, p + got, NULL); if (ret < 0) diff --git a/drivers/infiniband/hw/usnic/usnic_uiom.c b/drivers/infiniband/hw/usnic/usnic_uiom.c index 645a5f6e6c88..7209fbc03ccb 100644 --- a/drivers/infiniband/hw/usnic/usnic_uiom.c +++ b/drivers/infiniband/hw/usnic/usnic_uiom.c @@ -144,7 +144,7 @@ static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable, ret = 0; while (npages) { - ret = get_user_pages(current, current->mm, cur_base, + ret = get_user_pages(cur_base, min_t(unsigned long, npages, PAGE_SIZE / sizeof(struct page *)), 1, !writable, page_list, NULL); |