Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

Pull networking fixes from David Miller:

 1) Fix error path in netdevsim, from Jakub Kicinski.

 2) Default values listed in tcp_wmem and tcp_rmem documentation were
    inaccurate, from Tonghao Zhang.

 3) Fix route leaks in SCTP, both for ipv4 and ipv6. From Alexey Kodanev
    and Tommi Rantala.

 4) Fix "MASK < Y" meant to be "MASK << Y" in xgbe driver, from Wolfram
    Sang.

 5) Use after free in u32_destroy_key(), from Paolo Abeni.

 6) Fix two TX issues in be2net driver, from Suredh Reddy.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (25 commits)
  be2net: Handle transmit completion errors in Lancer
  be2net: Fix HW stall issue in Lancer
  RDS: IB: Fix null pointer issue
  nfp: fix kdoc warnings on nested structures
  sample/bpf: fix erspan metadata
  net: erspan: fix erspan config overwrite
  net: erspan: fix metadata extraction
  cls_u32: fix use after free in u32_destroy_key()
  net: amd-xgbe: fix comparison to bitshift when dealing with a mask
  net: phy: Handle not having GPIO enabled in the kernel
  ibmvnic: fix empty firmware version and errors cleanup
  sctp: fix dst refcnt leak in sctp_v4_get_dst
  sctp: fix dst refcnt leak in sctp_v6_get_dst()
  dwc-xlgmac: remove Jie Deng as co-maintainer
  doc: Change the min default value of tcp_wmem/tcp_rmem.
  samples/bpf: use bpf_set_link_xdp_fd
  libbpf: add missing SPDX-License-Identifier
  libbpf: add error reporting in XDP
  libbpf: add function to setup XDP
  tools: add netlink.h and if_link.h in tools uapi
  ...

2 files changed, 33 insertions, 2 deletions

diff --git a/Documentation/bpf/bpf_devel_QA.txt b/Documentation/bpf/bpf_devel_QA.txt
index cefef855dea4..84cbb302f2b5 100644
--- a/Documentation/bpf/bpf_devel_QA.txt
+++ b/Documentation/bpf/bpf_devel_QA.txt
@@ -516,4 +516,35 @@ A: LLVM has a -mcpu selector for the BPF back end in order to allow the
    By the way, the BPF kernel selftests run with -mcpu=probe for better
    test coverage.
 
+Q: In some cases clang flag "-target bpf" is used but in other cases the
+   default clang target, which matches the underlying architecture, is used.
+   What is the difference and when I should use which?
+
+A: Although LLVM IR generation and optimization try to stay architecture
+   independent, "-target <arch>" still has some impact on generated code:
+
+     - BPF program may recursively include header file(s) with file scope
+       inline assembly codes. The default target can handle this well,
+       while bpf target may fail if bpf backend assembler does not
+       understand these assembly codes, which is true in most cases.
+
+     - When compiled without -g, additional elf sections, e.g.,
+       .eh_frame and .rela.eh_frame, may be present in the object file
+       with default target, but not with bpf target.
+
+     - The default target may turn a C switch statement into a switch table
+       lookup and jump operation. Since the switch table is placed
+       in the global readonly section, the bpf program will fail to load.
+       The bpf target does not support switch table optimization.
+       The clang option "-fno-jump-tables" can be used to disable
+       switch table generation.
+
+   You should use default target when:
+
+     - Your program includes a header file, e.g., ptrace.h, which eventually
+       pulls in some header files containing file scope host assembly codes.
+     - You can add "-fno-jump-tables" to work around the switch table issue.
+
+   Otherwise, you can use bpf target.
+
 Happy BPF hacking!
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 3f2c40d8e6aa..a553d4e4a0fb 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -508,7 +508,7 @@ tcp_rmem - vector of 3 INTEGERs: min, default, max
 	min: Minimal size of receive buffer used by TCP sockets.
 	It is guaranteed to each TCP socket, even under moderate memory
 	pressure.
-	Default: 1 page
+	Default: 4K
 
 	default: initial size of receive buffer used by TCP sockets.
 	This value overrides net.core.rmem_default used by other protocols.
@@ -667,7 +667,7 @@ tcp_window_scaling - BOOLEAN
 tcp_wmem - vector of 3 INTEGERs: min, default, max
 	min: Amount of memory reserved for send buffers for TCP sockets.
 	Each TCP socket has rights to use it due to fact of its birth.
-	Default: 1 page
+	Default: 4K
 
 	default: initial size of send buffer used by TCP sockets.  This
 	value overrides net.core.wmem_default used by other protocols.