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  1. 18 1月, 2018 2 次提交
  3. 17 1月, 2018 1 次提交
  5. 16 1月, 2018 4 次提交
  7. 15 1月, 2018 5 次提交
  9. 14 1月, 2018 1 次提交
  11. 13 1月, 2018 2 次提交
    • M
      error-injection: Add injectable error types · 663faf9f
      由 Masami Hiramatsu 提交于 
      Add injectable error types for each error-injectable function.

One motivation of error injection test is to find software flaws,
mistakes or mis-handlings of expectable errors. If we find such
flaws by the test, that is a program bug, so we need to fix it.

But if the tester miss input the error (e.g. just return success
code without processing anything), it causes unexpected behavior
even if the caller is correctly programmed to handle any errors.
That is not what we want to test by error injection.

To clarify what type of errors the caller must expect for each
injectable function, this introduces injectable error types:

 - EI_ETYPE_NULL : means the function will return NULL if it
		    fails. No ERR_PTR, just a NULL.
 - EI_ETYPE_ERRNO : means the function will return -ERRNO
		    if it fails.
 - EI_ETYPE_ERRNO_NULL : means the function will return -ERRNO
		       (ERR_PTR) or NULL.

ALLOW_ERROR_INJECTION() macro is expanded to get one of
NULL, ERRNO, ERRNO_NULL to record the error type for
each function. e.g.

 ALLOW_ERROR_INJECTION(open_ctree, ERRNO)

This error types are shown in debugfs as below.

  ====
  / # cat /sys/kernel/debug/error_injection/list
  open_ctree [btrfs]	ERRNO
  io_ctl_init [btrfs]	ERRNO
  ====
Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      663faf9f
    • M
      error-injection: Separate error-injection from kprobe · 540adea3
      由 Masami Hiramatsu 提交于 
      Since error-injection framework is not limited to be used
by kprobes, nor bpf. Other kernel subsystems can use it
freely for checking safeness of error-injection, e.g.
livepatch, ftrace etc.
So this separate error-injection framework from kprobes.

Some differences has been made:

- "kprobe" word is removed from any APIs/structures.
- BPF_ALLOW_ERROR_INJECTION() is renamed to
  ALLOW_ERROR_INJECTION() since it is not limited for BPF too.
- CONFIG_FUNCTION_ERROR_INJECTION is the config item of this
  feature. It is automatically enabled if the arch supports
  error injection feature for kprobe or ftrace etc.
Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      540adea3
  13. 12 1月, 2018 2 次提交
    • S
      net/mlx5: Fix get vector affinity helper function · 05e0cc84
      由 Saeed Mahameed 提交于 
      mlx5_get_vector_affinity used to call pci_irq_get_affinity and after
reverting the patch that sets the device affinity via PCI_IRQ_AFFINITY
API, calling pci_irq_get_affinity becomes useless and it breaks RDMA
mlx5 users.  To fix this, this patch provides an alternative way to
retrieve IRQ vector affinity using legacy IRQ API, following
smp_affinity read procfs implementation.

Fixes: 231243c8 ("Revert mlx5: move affinity hints assignments to generic code")
Fixes: a435393a ("mlx5: move affinity hints assignments to generic code")
Cc: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>
      05e0cc84
    • E
      {net,ib}/mlx5: Don't disable local loopback multicast traffic when needed · 8978cc92
      由 Eran Ben Elisha 提交于 
      There are systems platform information management interfaces (such as
HOST2BMC) for which we cannot disable local loopback multicast traffic.

Separate disable_local_lb_mc and disable_local_lb_uc capability bits so
driver will not disable multicast loopback traffic if not supported.
(It is expected that Firmware will not set disable_local_lb_mc if
HOST2BMC is running for example.)

Function mlx5_nic_vport_update_local_lb will do best effort to
disable/enable UC/MC loopback traffic and return success only in case it
succeeded to changed all allowed by Firmware.

Adapt mlx5_ib and mlx5e to support the new cap bits.

Fixes: 2c43c5a0 ("net/mlx5e: Enable local loopback in loopback selftest")
Fixes: c85023e1 ("IB/mlx5: Add raw ethernet local loopback support")
Fixes: bded747b ("net/mlx5: Add raw ethernet local loopback firmware command")
Signed-off-by: NEran Ben Elisha <eranbe@mellanox.com>
Cc: kernel-team@fb.com
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>
      8978cc92
  15. 11 1月, 2018 4 次提交
  17. 10 1月, 2018 2 次提交
    • Q
      bpf: export function to write into verifier log buffer · 430e68d1
      由 Quentin Monnet 提交于 
      Rename the BPF verifier `verbose()` to `bpf_verifier_log_write()` and
export it, so that other components (in particular, drivers for BPF
offload) can reuse the user buffer log to dump error messages at
verification time.

Renaming `verbose()` was necessary in order to avoid a name so generic
to be exported to the global namespace. However to prevent too much pain
for backports, the calls to `verbose()` in the kernel BPF verifier were
not changed. Instead, use function aliasing to make `verbose` point to
`bpf_verifier_log_write`. Another solution could consist in making a
wrapper around `verbose()`, but since it is a variadic function, I don't
see a clean way without creating two identical wrappers, one for the
verifier and one to export.
Signed-off-by: NQuentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      430e68d1
    • D
      bpf: avoid false sharing of map refcount with max_entries · be95a845
      由 Daniel Borkmann 提交于 
      In addition to commit b2157399 ("bpf: prevent out-of-bounds
speculation") also change the layout of struct bpf_map such that
false sharing of fast-path members like max_entries is avoided
when the maps reference counter is altered. Therefore enforce
them to be placed into separate cachelines.

pahole dump after change:

  struct bpf_map {
        const struct bpf_map_ops  * ops;                 /*     0     8 */
        struct bpf_map *           inner_map_meta;       /*     8     8 */
        void *                     security;             /*    16     8 */
        enum bpf_map_type          map_type;             /*    24     4 */
        u32                        key_size;             /*    28     4 */
        u32                        value_size;           /*    32     4 */
        u32                        max_entries;          /*    36     4 */
        u32                        map_flags;            /*    40     4 */
        u32                        pages;                /*    44     4 */
        u32                        id;                   /*    48     4 */
        int                        numa_node;            /*    52     4 */
        bool                       unpriv_array;         /*    56     1 */

        /* XXX 7 bytes hole, try to pack */

        /* --- cacheline 1 boundary (64 bytes) --- */
        struct user_struct *       user;                 /*    64     8 */
        atomic_t                   refcnt;               /*    72     4 */
        atomic_t                   usercnt;              /*    76     4 */
        struct work_struct         work;                 /*    80    32 */
        char                       name[16];             /*   112    16 */
        /* --- cacheline 2 boundary (128 bytes) --- */

        /* size: 128, cachelines: 2, members: 17 */
        /* sum members: 121, holes: 1, sum holes: 7 */
  };

Now all entries in the first cacheline are read only throughout
the life time of the map, set up once during map creation. Overall
struct size and number of cachelines doesn't change from the
reordering. struct bpf_map is usually first member and embedded
in map structs in specific map implementations, so also avoid those
members to sit at the end where it could potentially share the
cacheline with first map values e.g. in the array since remote
CPUs could trigger map updates just as well for those (easily
dirtying members like max_entries intentionally as well) while
having subsequent values in cache.

Quoting from Google's Project Zero blog [1]:

  Additionally, at least on the Intel machine on which this was
  tested, bouncing modified cache lines between cores is slow,
  apparently because the MESI protocol is used for cache coherence
  [8]. Changing the reference counter of an eBPF array on one
  physical CPU core causes the cache line containing the reference
  counter to be bounced over to that CPU core, making reads of the
  reference counter on all other CPU cores slow until the changed
  reference counter has been written back to memory. Because the
  length and the reference counter of an eBPF array are stored in
  the same cache line, this also means that changing the reference
  counter on one physical CPU core causes reads of the eBPF array's
  length to be slow on other physical CPU cores (intentional false
  sharing).

While this doesn't 'control' the out-of-bounds speculation through
masking the index as in commit b2157399, triggering a manipulation
of the map's reference counter is really trivial, so lets not allow
to easily affect max_entries from it.

Splitting to separate cachelines also generally makes sense from
a performance perspective anyway in that fast-path won't have a
cache miss if the map gets pinned, reused in other progs, etc out
of control path, thus also avoids unintentional false sharing.

  [1] https://googleprojectzero.blogspot.ch/2018/01/reading-privileged-memory-with-side.htmlSigned-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      be95a845
  19. 09 1月, 2018 17 次提交