Skip to content

L
linux
Switch branch/tag
  1. 15 May, 2017 5 commits
  3. 12 May, 2017 22 commits
  5. 11 May, 2017 13 commits
    • David S. Miller's avatar
      bpf: Provide a linux/types.h override for bpf selftests. · 0a5539f6
      David S. Miller authored 
      We do not want to use the architecture's type.h header when
building BPF programs which are always 64-bit.
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      0a5539f6
    • David S. Miller's avatar
      Merge branch 'bpf-pkt-ptr-align' · 228b0324
      David S. Miller authored 
      David S. Miller says:

====================
bpf: Add alignment tracker to verifier.

First we add the alignment tracking logic to the verifier.

Next, we work on building up infrastructure to facilitate regression
testing of this facility.

Finally, we add the "test_align" test case.
====================
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      228b0324
    • David S. Miller's avatar
      bpf: Add verifier test case for alignment. · 18b3ad90
      David S. Miller authored 
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      18b3ad90
    • David S. Miller's avatar
      bpf: Add bpf_verify_program() to the library. · 91045f5e
      David S. Miller authored 
      This allows a test case to load a BPF program and unconditionally
acquire the verifier log.

It also allows specification of the strict alignment flag.
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      91045f5e
    • David S. Miller's avatar
      bpf: Add strict alignment flag for BPF_PROG_LOAD. · e07b98d9
      David S. Miller authored 
      Add a new field, "prog_flags", and an initial flag value
BPF_F_STRICT_ALIGNMENT.

When set, the verifier will enforce strict pointer alignment
regardless of the setting of CONFIG_EFFICIENT_UNALIGNED_ACCESS.

The verifier, in this mode, will also use a fixed value of "2" in
place of NET_IP_ALIGN.

This facilitates test cases that will exercise and validate this part
of the verifier even when run on architectures where alignment doesn't
matter.
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      e07b98d9
    • David S. Miller's avatar
      bpf: Do per-instruction state dumping in verifier when log_level > 1. · c5fc9692
      David S. Miller authored 
      If log_level > 1, do a state dump every instruction and emit it in
a more compact way (without a leading newline).

This will facilitate more sophisticated test cases which inspect the
verifier log for register state.
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      c5fc9692
    • David S. Miller's avatar
      bpf: Track alignment of register values in the verifier. · d1174416
      David S. Miller authored 
      Currently if we add only constant values to pointers we can fully
validate the alignment, and properly check if we need to reject the
program on !CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS architectures.

However, once an unknown value is introduced we only allow byte sized
memory accesses which is too restrictive.

Add logic to track the known minimum alignment of register values,
and propagate this state into registers containing pointers.

The most common paradigm that makes use of this new logic is computing
the transport header using the IP header length field.  For example:

	struct ethhdr *ep = skb->data;
	struct iphdr *iph = (struct iphdr *) (ep + 1);
	struct tcphdr *th;
 ...
	n = iph->ihl;
	th = ((void *)iph + (n * 4));
	port = th->dest;

The existing code will reject the load of th->dest because it cannot
validate that the alignment is at least 2 once "n * 4" is added the
the packet pointer.

In the new code, the register holding "n * 4" will have a reg->min_align
value of 4, because any value multiplied by 4 will be at least 4 byte
aligned.  (actually, the eBPF code emitted by the compiler in this case
is most likely to use a shift left by 2, but the end result is identical)

At the critical addition:

	th = ((void *)iph + (n * 4));

The register holding 'th' will start with reg->off value of 14.  The
pointer addition will transform that reg into something that looks like:

	reg->aux_off = 14
	reg->aux_off_align = 4

Next, the verifier will look at the th->dest load, and it will see
a load offset of 2, and first check:

	if (reg->aux_off_align % size)

which will pass because aux_off_align is 4.  reg_off will be computed:

	reg_off = reg->off;
 ...
		reg_off += reg->aux_off;

plus we have off==2, and it will thus check:

	if ((NET_IP_ALIGN + reg_off + off) % size != 0)

which evaluates to:

	if ((NET_IP_ALIGN + 14 + 2) % size != 0)

On strict alignment architectures, NET_IP_ALIGN is 2, thus:

	if ((2 + 14 + 2) % size != 0)

which passes.

These pointer transformations and checks work regardless of whether
the constant offset or the variable with known alignment is added
first to the pointer register.
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      d1174416
    • Daniel Borkmann's avatar
      bpf, arm64: fix faulty emission of map access in tail calls · d8b54110
      Daniel Borkmann authored 
      Shubham was recently asking on netdev why in arm64 JIT we don't multiply
the index for accessing the tail call map by 8. That led me into testing
out arm64 JIT wrt tail calls and it turned out I got a NULL pointer
dereference on the tail call.

The buggy access is at:

  prog = array->ptrs[index];
  if (prog == NULL)
      goto out;

  [...]
  00000060:  d2800e0a  mov x10, #0x70 // #112
  00000064:  f86a682a  ldr x10, [x1,x10]
  00000068:  f862694b  ldr x11, [x10,x2]
  0000006c:  b40000ab  cbz x11, 0x00000080
  [...]

The code triggering the crash is f862694b. x1 at the time contains the
address of the bpf array, x10 offsetof(struct bpf_array, ptrs). Meaning,
above we load the pointer to the program at map slot 0 into x10. x10
can then be NULL if the slot is not occupied, which we later on try to
access with a user given offset in x2 that is the map index.

Fix this by emitting the following instead:

  [...]
  00000060:  d2800e0a  mov x10, #0x70 // #112
  00000064:  8b0a002a  add x10, x1, x10
  00000068:  d37df04b  lsl x11, x2, #3
  0000006c:  f86b694b  ldr x11, [x10,x11]
  00000070:  b40000ab  cbz x11, 0x00000084
  [...]

This basically adds the offset to ptrs to the base address of the bpf
array we got and we later on access the map with an index * 8 offset
relative to that. The tail call map itself is basically one large area
with meta data at the head followed by the array of prog pointers.
This makes tail calls working again, tested on Cavium ThunderX ARMv8.

Fixes: ddb55992 ("arm64: bpf: implement bpf_tail_call() helper")
Reported-by: default avatarShubham Bansal <illusionist.neo@gmail.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      d8b54110
    • Ivan Khoronzhuk's avatar
      net: ethernet: ti: netcp_core: return error while dma channel open issue · 5b6cb43b
      Ivan Khoronzhuk authored 
      Fix error path while dma open channel issue. Also, no need to check output
on NULL if it's never returned.
Signed-off-by: default avatarIvan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      5b6cb43b
    • David S. Miller's avatar
      Merge branch 's390-net-fixes' · dc319c4b
      David S. Miller authored 
      Julian Wiedmann says:

====================
s390/net fixes

some qeth fixes for -net, the OSM/OSN one being the most crucial.
Please also queue these up for stable.
====================
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      dc319c4b
    • Ursula Braun's avatar
      s390/qeth: add missing hash table initializations · ebccc739
      Ursula Braun authored 
      commit 5f78e29c ("qeth: optimize IP handling in rx_mode callback")
added new hash tables, but missed to initialize them.

Fixes: 5f78e29c ("qeth: optimize IP handling in rx_mode callback")
Signed-off-by: default avatarUrsula Braun <ubraun@linux.vnet.ibm.com>
Reviewed-by: default avatarJulian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: default avatarJulian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      ebccc739
    • Julian Wiedmann's avatar
      s390/qeth: avoid null pointer dereference on OSN · 25e2c341
      Julian Wiedmann authored 
      Access card->dev only after checking whether's its valid.
Signed-off-by: default avatarJulian Wiedmann <jwi@linux.vnet.ibm.com>
Reviewed-by: default avatarUrsula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      25e2c341
    • Julian Wiedmann's avatar
      s390/qeth: unbreak OSM and OSN support · 2d2ebb3e
      Julian Wiedmann authored 
      commit b4d72c08 ("qeth: bridgeport support - basic control")
broke the support for OSM and OSN devices as follows:

As OSM and OSN are L2 only, qeth_core_probe_device() does an early
setup by loading the l2 discipline and calling qeth_l2_probe_device().
In this context, adding the l2-specific bridgeport sysfs attributes
via qeth_l2_create_device_attributes() hits a BUG_ON in fs/sysfs/group.c,
since the basic sysfs infrastructure for the device hasn't been
established yet.

Note that OSN actually has its own unique sysfs attributes
(qeth_osn_devtype), so the additional attributes shouldn't be created
at all.
For OSM, add a new qeth_l2_devtype that contains all the common
and l2-specific sysfs attributes.
When qeth_core_probe_device() does early setup for OSM or OSN, assign
the corresponding devtype so that the ccwgroup probe code creates the
full set of sysfs attributes.
This allows us to skip qeth_l2_create_device_attributes() in case
of an early setup.

Any device that can't do early setup will initially have only the
generic sysfs attributes, and when it's probed later
qeth_l2_probe_device() adds the l2-specific attributes.

If an early-setup device is removed (by calling ccwgroup_ungroup()),
device_unregister() will - using the devtype - delete the
l2-specific attributes before qeth_l2_remove_device() is called.
So make sure to not remove them twice.

What complicates the issue is that qeth_l2_probe_device() and
qeth_l2_remove_device() is also called on a device when its
layer2 attribute changes (ie. its layer mode is switched).
For early-setup devices this wouldn't work properly - we wouldn't
remove the l2-specific attributes when switching to L3.
But switching the layer mode doesn't actually make any sense;
we already decided that the device can only operate in L2!
So just refuse to switch the layer mode on such devices. Note that
OSN doesn't have a layer2 attribute, so we only need to special-case
OSM.

Based on an initial patch by Ursula Braun.

Fixes: b4d72c08 ("qeth: bridgeport support - basic control")
Signed-off-by: default avatarJulian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      2d2ebb3e
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7