Skip to content

K
Kernel

openeuler / Kernel
接近 2 年 前同步成功

通知 8
Star 0
Fork 0
K
Kernel
切换分支/标签
  1. 20 12月, 2017 2 次提交
  3. 19 12月, 2017 4 次提交
    • M
      net: Introduce NETIF_F_GRO_HW. · fb1f5f79
      由 Michael Chan 提交于 
      Introduce NETIF_F_GRO_HW feature flag for NICs that support hardware
GRO.  With this flag, we can now independently turn on or off hardware
GRO when GRO is on.  Previously, drivers were using NETIF_F_GRO to
control hardware GRO and so it cannot be independently turned on or
off without affecting GRO.

Hardware GRO (just like GRO) guarantees that packets can be re-segmented
by TSO/GSO to reconstruct the original packet stream.  Logically,
GRO_HW should depend on GRO since it a subset, but we will let
individual drivers enforce this dependency as they see fit.

Since NETIF_F_GRO is not propagated between upper and lower devices,
NETIF_F_GRO_HW should follow suit since it is a subset of GRO.  In other
words, a lower device can independent have GRO/GRO_HW enabled or disabled
and no feature propagation is required.  This will preserve the current
GRO behavior.  This can be changed later if we decide to propagate GRO/
GRO_HW/RXCSUM from upper to lower devices.

Cc: Ariel Elior <Ariel.Elior@cavium.com>
Cc: everest-linux-l2@cavium.com
Signed-off-by: NMichael Chan <michael.chan@broadcom.com>
Acked-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      fb1f5f79
    • T
      sock: Hide unused variable when !CONFIG_PROC_FS. · 398b841e
      由 Tonghao Zhang 提交于 
      When CONFIG_PROC_FS is disabled, we will not use the prot_inuse
counter. This adds an #ifdef to hide the variable definition in
that case. This is not a bugfix. But we can save bytes when there
are many network namespace.

Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: NMartin Zhang <zhangjunweimartin@didichuxing.com>
Signed-off-by: NTonghao Zhang <zhangtonghao@didichuxing.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      398b841e
    • T
      sock: Move the socket inuse to namespace. · 648845ab
      由 Tonghao Zhang 提交于 
      In some case, we want to know how many sockets are in use in
different _net_ namespaces. It's a key resource metric.

This patch add a member in struct netns_core. This is a counter
for socket-inuse in the _net_ namespace. The patch will add/sub
counter in the sk_alloc, sk_clone_lock and __sk_free.

This patch will not counter the socket created in kernel.
It's not very useful for userspace to know how many kernel
sockets we created.

The main reasons for doing this are that:

1. When linux calls the 'do_exit' for process to exit, the functions
'exit_task_namespaces' and 'exit_task_work' will be called sequentially.
'exit_task_namespaces' may have destroyed the _net_ namespace, but
'sock_release' called in 'exit_task_work' may use the _net_ namespace
if we counter the socket-inuse in sock_release.

2. socket and sock are in pair. More important, sock holds the _net_
namespace. We counter the socket-inuse in sock, for avoiding holding
_net_ namespace again in socket. It's a easy way to maintain the code.
Signed-off-by: NMartin Zhang <zhangjunweimartin@didichuxing.com>
Signed-off-by: NTonghao Zhang <zhangtonghao@didichuxing.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      648845ab
    • T
      sock: Change the netns_core member name. · 08fc7f81
      由 Tonghao Zhang 提交于 
      Change the member name will make the code more readable.
This patch will be used in next patch.
Signed-off-by: NMartin Zhang <zhangjunweimartin@didichuxing.com>
Signed-off-by: NTonghao Zhang <zhangtonghao@didichuxing.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      08fc7f81
  5. 18 12月, 2017 6 次提交
    • A
      bpf: x64: add JIT support for multi-function programs · 1c2a088a
      由 Alexei Starovoitov 提交于 
      Typical JIT does several passes over bpf instructions to
compute total size and relative offsets of jumps and calls.
With multitple bpf functions calling each other all relative calls
will have invalid offsets intially therefore we need to additional
last pass over the program to emit calls with correct offsets.
For example in case of three bpf functions:
main:
  call foo
  call bpf_map_lookup
  exit
foo:
  call bar
  exit
bar:
  exit

We will call bpf_int_jit_compile() indepedently for main(), foo() and bar()
x64 JIT typically does 4-5 passes to converge.
After these initial passes the image for these 3 functions
will be good except call targets, since start addresses of
foo() and bar() are unknown when we were JITing main()
(note that call bpf_map_lookup will be resolved properly
during initial passes).
Once start addresses of 3 functions are known we patch
call_insn->imm to point to right functions and call
bpf_int_jit_compile() again which needs only one pass.
Additional safety checks are done to make sure this
last pass doesn't produce image that is larger or smaller
than previous pass.

When constant blinding is on it's applied to all functions
at the first pass, since doing it once again at the last
pass can change size of the JITed code.

Tested on x64 and arm64 hw with JIT on/off, blinding on/off.
x64 jits bpf-to-bpf calls correctly while arm64 falls back to interpreter.
All other JITs that support normal BPF_CALL will behave the same way
since bpf-to-bpf call is equivalent to bpf-to-kernel call from
JITs point of view.
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      1c2a088a
    • A
      bpf: fix net.core.bpf_jit_enable race · 60b58afc
      由 Alexei Starovoitov 提交于 
      global bpf_jit_enable variable is tested multiple times in JITs,
blinding and verifier core. The malicious root can try to toggle
it while loading the programs. This race condition was accounted
for and there should be no issues, but it's safer to avoid
this race condition.
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      60b58afc
    • A
      bpf: add support for bpf_call to interpreter · 1ea47e01
      由 Alexei Starovoitov 提交于 
      though bpf_call is still the same call instruction and
calling convention 'bpf to bpf' and 'bpf to helper' is the same
the interpreter has to oparate on 'struct bpf_insn *'.
To distinguish these two cases add a kernel internal opcode and
mark call insns with it.
This opcode is seen by interpreter only. JITs will never see it.
Also add tiny bit of debug code to aid interpreter debugging.
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      1ea47e01
    • A
      bpf: teach verifier to recognize zero initialized stack · cc2b14d5
      由 Alexei Starovoitov 提交于 
      programs with function calls are often passing various
pointers via stack. When all calls are inlined llvm
flattens stack accesses and optimizes away extra branches.
When functions are not inlined it becomes the job of
the verifier to recognize zero initialized stack to avoid
exploring paths that program will not take.
The following program would fail otherwise:

ptr = &buffer_on_stack;
*ptr = 0;
...
func_call(.., ptr, ...) {
  if (..)
    *ptr = bpf_map_lookup();
}
...
if (*ptr != 0) {
  // Access (*ptr)->field is valid.
  // Without stack_zero tracking such (*ptr)->field access
  // will be rejected
}

since stack slots are no longer uniform invalid | spill | misc
add liveness marking to all slots, but do it in 8 byte chunks.
So if nothing was read or written in [fp-16, fp-9] range
it will be marked as LIVE_NONE.
If any byte in that range was read, it will be marked LIVE_READ
and stacksafe() check will perform byte-by-byte verification.
If all bytes in the range were written the slot will be
marked as LIVE_WRITTEN.
This significantly speeds up state equality comparison
and reduces total number of states processed.

                    before   after
bpf_lb-DLB_L3.o       2051    2003
bpf_lb-DLB_L4.o       3287    3164
bpf_lb-DUNKNOWN.o     1080    1080
bpf_lxc-DDROP_ALL.o   24980   12361
bpf_lxc-DUNKNOWN.o    34308   16605
bpf_netdev.o          15404   10962
bpf_overlay.o         7191    6679
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      cc2b14d5
    • A
      bpf: introduce function calls (verification) · f4d7e40a
      由 Alexei Starovoitov 提交于 
      Allow arbitrary function calls from bpf function to another bpf function.

To recognize such set of bpf functions the verifier does:
1. runs control flow analysis to detect function boundaries
2. proceeds with verification of all functions starting from main(root) function
It recognizes that the stack of the caller can be accessed by the callee
(if the caller passed a pointer to its stack to the callee) and the callee
can store map_value and other pointers into the stack of the caller.
3. keeps track of the stack_depth of each function to make sure that total
stack depth is still less than 512 bytes
4. disallows pointers to the callee stack to be stored into the caller stack,
since they will be invalid as soon as the callee returns
5. to reuse all of the existing state_pruning logic each function call
is considered to be independent call from the verifier point of view.
The verifier pretends to inline all function calls it sees are being called.
It stores the callsite instruction index as part of the state to make sure
that two calls to the same callee from two different places in the caller
will be different from state pruning point of view
6. more safety checks are added to liveness analysis

Implementation details:
. struct bpf_verifier_state is now consists of all stack frames that
  led to this function
. struct bpf_func_state represent one stack frame. It consists of
  registers in the given frame and its stack
. propagate_liveness() logic had a premature optimization where
  mark_reg_read() and mark_stack_slot_read() were manually inlined
  with loop iterating over parents for each register or stack slot.
  Undo this optimization to reuse more complex mark_*_read() logic
. skip_callee() logic is not necessary from safety point of view,
  but without it mark_*_read() markings become too conservative,
  since after returning from the funciton call a read of r6-r9
  will incorrectly propagate the read marks into callee causing
  inefficient pruning later
. mark_*_read() logic is now aware of control flow which makes it
  more complex. In the future the plan is to rewrite liveness
  to be hierarchical. So that liveness can be done within
  basic block only and control flow will be responsible for
  propagation of liveness information along cfg and between calls.
. tail_calls and ld_abs insns are not allowed in the programs with
  bpf-to-bpf calls
. returning stack pointers to the caller or storing them into stack
  frame of the caller is not allowed

Testing:
. no difference in cilium processed_insn numbers
. large number of tests follows in next patches
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NJohn Fastabend <john.fastabend@gmail.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      f4d7e40a
    • A
      bpf: introduce function calls (function boundaries) · cc8b0b92
      由 Alexei Starovoitov 提交于 
      Allow arbitrary function calls from bpf function to another bpf function.

Since the beginning of bpf all bpf programs were represented as a single function
and program authors were forced to use always_inline for all functions
in their C code. That was causing llvm to unnecessary inflate the code size
and forcing developers to move code to header files with little code reuse.

With a bit of additional complexity teach verifier to recognize
arbitrary function calls from one bpf function to another as long as
all of functions are presented to the verifier as a single bpf program.
New program layout:
r6 = r1    // some code
..
r1 = ..    // arg1
r2 = ..    // arg2
call pc+1  // function call pc-relative
exit
.. = r1    // access arg1
.. = r2    // access arg2
..
call pc+20 // second level of function call
...

It allows for better optimized code and finally allows to introduce
the core bpf libraries that can be reused in different projects,
since programs are no longer limited by single elf file.
With function calls bpf can be compiled into multiple .o files.

This patch is the first step. It detects programs that contain
multiple functions and checks that calls between them are valid.
It splits the sequence of bpf instructions (one program) into a set
of bpf functions that call each other. Calls to only known
functions are allowed. In the future the verifier may allow
calls to unresolved functions and will do dynamic linking.
This logic supports statically linked bpf functions only.

Such function boundary detection could have been done as part of
control flow graph building in check_cfg(), but it's cleaner to
separate function boundary detection vs control flow checks within
a subprogram (function) into logically indepedent steps.
Follow up patches may split check_cfg() further, but not check_subprogs().

Only allow bpf-to-bpf calls for root only and for non-hw-offloaded programs.
These restrictions can be relaxed in the future.
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      cc8b0b92
  7. 16 12月, 2017 12 次提交
  9. 15 12月, 2017 6 次提交
  11. 14 12月, 2017 10 次提交