When CONFIG_NET is not defined, I hit the following build error:
    kernel/trace/bpf_trace.o:(.rodata+0x110): undefined reference to `bpf_prog_test_run_raw_tp'

Commit 1b4d60ec ("bpf: Enable BPF_PROG_TEST_RUN for raw_tracepoint")
added test_run support for raw_tracepoint in /kernel/trace/bpf_trace.c.
But the test_run function bpf_prog_test_run_raw_tp is defined in
net/bpf/test_run.c, only available with CONFIG_NET=y.

Adding a CONFIG_NET guard for
    .test_run = bpf_prog_test_run_raw_tp;
fixed the above build issue.

Fixes: 1b4d60ec

 ("bpf: Enable BPF_PROG_TEST_RUN for raw_tracepoint")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201007062933.3425899-1-yhs@fb.com

Fix build errors in kernel/bpf/verifier.c when CONFIG_NET is
not enabled.

../kernel/bpf/verifier.c:3995:13: error: ‘btf_sock_ids’ undeclared here (not in a function); did you mean ‘bpf_sock_ops’?
  .btf_id = &btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON],

../kernel/bpf/verifier.c:3995:26: error: ‘BTF_SOCK_TYPE_SOCK_COMMON’ undeclared here (not in a function); did you mean ‘PTR_TO_SOCK_COMMON’?
  .btf_id = &btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON],

Fixes: 1df8f55a

 ("bpf: Enable bpf_skc_to_* sock casting helper to networking prog type")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20201007021613.13646-1-rdunlap@infradead.org

Commit 4976b718 ("bpf: Introduce pseudo_btf_id") switched
the order of check_subprogs() and resolve_pseudo_ldimm() in
the verifier. Now an empty prog expects to see the error "last
insn is not an the prog of a single invalid ldimm exit or jmp"
instead, because the check for subprogs comes first. It's now
pointless to validate that half of ldimm64 won't be the last
instruction.

Tested:
 # ./test_verifier
 Summary: 1129 PASSED, 537 SKIPPED, 0 FAILED
 and the full set of bpf selftests.

Fixes: 4976b718

 ("bpf: Introduce pseudo_btf_id")
Signed-off-by: Hao Luo <haoluo@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201007022857.2791884-1-haoluo@google.com

Add an option to count the number of interrupts generated per second and
total number of interrupts during the lifetime of the application for a
given interface. This information is extracted from /proc/interrupts. Since
there is no naming convention across drivers, the user must provide the
string which is specific to their interface in the /proc/interrupts file on
the command line.

Usage:

./xdpsock ... -I <irq_str>

eg. for queue 0 of i40e device eth0:

./xdpsock ... -I i40e-eth0-TxRx-0

Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201002133612.31536-3-ciara.loftus@intel.com

Categorise and record syscalls issued in the xdpsock sample app. The
categories recorded are:

  rx_empty_polls:    polls when the rx ring is empty
  fill_fail_polls:   polls when failed to get addr from fill ring
  copy_tx_sendtos:   sendtos issued for tx when copy mode enabled
  tx_wakeup_sendtos: sendtos issued when tx ring needs waking up
  opt_polls:         polls issued since the '-p' flag is set

Print the stats using '-a' on the xdpsock command line.

Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20201002133612.31536-2-ciara.loftus@intel.com

New statistics will be added in future commits. In preparation for this,
let's split out the existing statistics into their own struct.

Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20201002133612.31536-1-ciara.loftus@intel.com

Compiling samples/bpf hits an error related to fallthrough marking.
    ...
    CC  samples/bpf/hbm.o
  samples/bpf/hbm.c: In function ‘main’:
  samples/bpf/hbm.c:486:4: error: ‘fallthrough’ undeclared (first use in this function)
      fallthrough;
      ^~~~~~~~~~~

The "fallthrough" is not defined under tools/include directory.
Rather, it is "__fallthrough" is defined in linux/compiler.h.
Including "linux/compiler.h" and using "__fallthrough" fixed the issue.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201006043427.1891805-1-yhs@fb.com

With latest llvm trunk, bpf programs under samples/bpf
directory, if using CORE, may experience the following
errors:

LLVM ERROR: Cannot select: intrinsic %llvm.preserve.struct.access.index
PLEASE submit a bug report to https://bugs.llvm.org/ and include the crash backtrace.
Stack dump:
0.      Program arguments: llc -march=bpf -filetype=obj -o samples/bpf/test_probe_write_user_kern.o
1.      Running pass 'Function Pass Manager' on module '<stdin>'.
2.      Running pass 'BPF DAG->DAG Pattern Instruction Selection' on function '@bpf_prog1'
 #0 0x000000000183c26c llvm::sys::PrintStackTrace(llvm::raw_ostream&, int)
    (/data/users/yhs/work/llvm-project/llvm/build.cur/install/bin/llc+0x183c26c)
...
 #7 0x00000000017c375e (/data/users/yhs/work/llvm-project/llvm/build.cur/install/bin/llc+0x17c375e)
 #8 0x00000000016a75c5 llvm::SelectionDAGISel::CannotYetSelect(llvm::SDNode*)
    (/data/users/yhs/work/llvm-project/llvm/build.cur/install/bin/llc+0x16a75c5)
 #9 0x00000000016ab4f8 llvm::SelectionDAGISel::SelectCodeCommon(llvm::SDNode*, unsigned char const*,
    unsigned int) (/data/users/yhs/work/llvm-project/llvm/build.cur/install/bin/llc+0x16ab4f8)
...
Aborted (core dumped) | llc -march=bpf -filetype=obj -o samples/bpf/test_probe_write_user_kern.o

The reason is due to llvm change https://reviews.llvm.org/D87153


where the CORE relocation global generation is moved from the beginning
of target dependent optimization (llc) to the beginning
of target independent optimization (opt).

Since samples/bpf programs did not use vmlinux.h and its clang compilation
uses native architecture, we need to adjust arch triple at opt level
to do CORE relocation global generation properly. Otherwise, the above
error will appear.

This patch fixed the issue by introduce opt and llvm-dis to compilation chain,
which will do proper CORE relocation global generation as well as O2 level
optimization. Tested with llvm10, llvm11 and trunk/llvm12.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20201006043427.1891742-1-yhs@fb.com

bpf_program__set_attach_target(prog, fd, ...) will always fail when
fd = 0 (attach to a kernel symbol) because obj->btf_vmlinux is NULL
and there is no way to set it (at the moment btf_vmlinux is meant
to be temporary storage for use in bpf_object__load_xattr()).

Fix this by using libbpf_find_vmlinux_btf_id().

At some point we may want to opportunistically cache btf_vmlinux
so it can be reused with multiple programs.

Signed-off-by: Luigi Rizzo <lrizzo@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Petar Penkov <ppenkov@google.com>
Link: https://lore.kernel.org/bpf/20201005224528.389097-1-lrizzo@google.com

Hangbin Liu says:

====================
When a user reuse map fd after creating a map manually and set the
pin_path, then load the object via libbpf. bpf_object__create_maps()
will skip pinning map if map fd exist. Fix it by add moving bpf creation
to else condition and go on checking map pin_path after that.

v3:
for selftest: use CHECK() for bpf_object__open_file() and close map fd on error

v2:
a) close map fd if init map slots failed
b) add bpf selftest for this scenario
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

This add a test to make sure that we can still pin maps with
reused map fd.

Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201006021345.3817033-4-liuhangbin@gmail.com

Say a user reuse map fd after creating a map manually and set the
pin_path, then load the object via libbpf.

In libbpf bpf_object__create_maps(), bpf_object__reuse_map() will
return 0 if there is no pinned map in map->pin_path. Then after
checking if map fd exist, we should also check if pin_path was set
and do bpf_map__pin() instead of continue the loop.

Fix it by creating map if fd not exist and continue checking pin_path
after that.

Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201006021345.3817033-3-liuhangbin@gmail.com

Previously we forgot to close the map fd if bpf_map_update_elem()
failed during map slot init, which will leak map fd.

Let's move map slot initialization to new function init_map_slots() to
simplify the code. And close the map fd if init slot failed.

Reported-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201006021345.3817033-2-liuhangbin@gmail.com

Update Andrii Nakryiko's reviewer email to kernel.org account. This optimizes
email logistics on my side and makes it less likely for me to miss important
patches.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20201005223648.2437130-1-andrii@kernel.org

Recent improvements in LOCKDEP highlighted a potential A-A deadlock with
pcpu_freelist in NMI:

./tools/testing/selftests/bpf/test_progs -t stacktrace_build_id_nmi

[   18.984807] ================================
[   18.984807] WARNING: inconsistent lock state
[   18.984808] 5.9.0-rc6-01771-g1466de1330e1 #2967 Not tainted
[   18.984809] --------------------------------
[   18.984809] inconsistent {INITIAL USE} -> {IN-NMI} usage.
[   18.984810] test_progs/1990 [HC2[2]:SC0[0]:HE0:SE1] takes:
[   18.984810] ffffe8ffffc219c0 (&head->lock){....}-{2:2}, at: __pcpu_freelist_pop+0xe3/0x180
[   18.984813] {INITIAL USE} state was registered at:
[   18.984814]   lock_acquire+0x175/0x7c0
[   18.984814]   _raw_spin_lock+0x2c/0x40
[   18.984815]   __pcpu_freelist_pop+0xe3/0x180
[   18.984815]   pcpu_freelist_pop+0x31/0x40
[   18.984816]   htab_map_alloc+0xbbf/0xf40
[   18.984816]   __do_sys_bpf+0x5aa/0x3ed0
[   18.984817]   do_syscall_64+0x2d/0x40
[   18.984818]   entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   18.984818] irq event stamp: 12
[...]
[   18.984822] other info that might help us debug this:
[   18.984823]  Possible unsafe locking scenario:
[   18.984823]
[   18.984824]        CPU0
[   18.984824]        ----
[   18.984824]   lock(&head->lock);
[   18.984826]   <Interrupt>
[   18.984826]     lock(&head->lock);
[   18.984827]
[   18.984828]  *** DEADLOCK ***
[   18.984828]
[   18.984829] 2 locks held by test_progs/1990:
[...]
[   18.984838]  <NMI>
[   18.984838]  dump_stack+0x9a/0xd0
[   18.984839]  lock_acquire+0x5c9/0x7c0
[   18.984839]  ? lock_release+0x6f0/0x6f0
[   18.984840]  ? __pcpu_freelist_pop+0xe3/0x180
[   18.984840]  _raw_spin_lock+0x2c/0x40
[   18.984841]  ? __pcpu_freelist_pop+0xe3/0x180
[   18.984841]  __pcpu_freelist_pop+0xe3/0x180
[   18.984842]  pcpu_freelist_pop+0x17/0x40
[   18.984842]  ? lock_release+0x6f0/0x6f0
[   18.984843]  __bpf_get_stackid+0x534/0xaf0
[   18.984843]  bpf_prog_1fd9e30e1438d3c5_oncpu+0x73/0x350
[   18.984844]  bpf_overflow_handler+0x12f/0x3f0

This is because pcpu_freelist_head.lock is accessed in both NMI and
non-NMI context. Fix this issue by using raw_spin_trylock() in NMI.

Since NMI interrupts non-NMI context, when NMI context tries to lock the
raw_spinlock, non-NMI context of the same CPU may already have locked a
lock and is blocked from unlocking the lock. For a system with N CPUs,
there could be N NMIs at the same time, and they may block N non-NMI
raw_spinlocks. This is tricky for pcpu_freelist_push(), where unlike
_pop(), failing _push() means leaking memory. This issue is more likely to
trigger in non-SMP system.

Fix this issue with an extra list, pcpu_freelist.extralist. The extralist
is primarily used to take _push() when raw_spin_trylock() failed on all
the per CPU lists. It should be empty most of the time. The following
table summarizes the behavior of pcpu_freelist in NMI and non-NMI:

non-NMI pop(): 	use _lock(); check per CPU lists first;
                if all per CPU lists are empty, check extralist;
                if extralist is empty, return NULL.

non-NMI push(): use _lock(); only push to per CPU lists.

NMI pop():    use _trylock(); check per CPU lists first;
              if all per CPU lists are locked or empty, check extralist;
              if extralist is locked or empty, return NULL.

NMI push():   use _trylock(); check per CPU lists first;
              if all per CPU lists are locked; try push to extralist;
              if extralist is also locked, keep trying on per CPU lists.

Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20201005165838.3735218-1-songliubraving@fb.com

Replace /* fallthrough */ comments with the new pseudo-keyword
macro fallthrough [1].

  [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through



Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20201002234217.GA12280@embeddedor

Christoph Hellwig correctly pointed out [1] that the AF_XDP core was
pointlessly including internal headers. Let us remove those includes.

  [1] https://lore.kernel.org/bpf/20201005084341.GA3224@infradead.org/

Fixes: 1c1efc2a

 ("xsk: Create and free buffer pool independently from umem")
Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/bpf/20201005090525.116689-1-bjorn.topel@gmail.com

We are missing a deref for the case when we are doing BPF_PROG_BIND_MAP
on a map that's being already held by the program.
There is 'if (ret) bpf_map_put(map)' below which doesn't trigger
because we don't consider this an error.
Let's add missing bpf_map_put() for this specific condition.

Fixes: ef15314a

 ("bpf: Add BPF_PROG_BIND_MAP syscall")
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20201003002544.3601440-1-sdf@google.com

John Fastabend says:

====================
This implements the helper skb_adjust_room() for BPF_SKS_SK_STREAM_VERDICT
programs so we can push/pop headers from the data on recieve. One use
case is to pop TLS headers off kTLS packets.

The first patch implements the helper and the second updates test_sockmap
to use it removing some case handling we had to do earlier to account for
the TLS headers in the kTLS tests.

v1->v2:
 Fix error path for TLS case (Daniel)
 check mode input is 0 because we don't use it now (Daniel)
 Remove incorrect/misleading comment (Lorenz)

Thanks,
John
Acked-by: Martin KaFai Lau <kafai@fb.com>
---
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Instead of working around TLS headers in sockmap selftests use the
new skb_adjust_room helper. This allows us to avoid special casing
the receive side to skip headers.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/160160100932.7052.3646935243867660528.stgit@john-Precision-5820-Tower

This implements a new helper skb_adjust_room() so users can push/pop
extra bytes from a BPF_SK_SKB_STREAM_VERDICT program.

Some protocols may include headers and other information that we may
not want to include when doing a redirect from a BPF_SK_SKB_STREAM_VERDICT
program. One use case is to redirect TLS packets into a receive socket
that doesn't expect TLS data. In TLS case the first 13B or so contain the
protocol header. With KTLS the payload is decrypted so we should be able
to redirect this to a receiving socket, but the receiving socket may not
be expecting to receive a TLS header and discard the data. Using the
above helper we can pop the header off and put an appropriate header on
the payload. This allows for creating a proxy between protocols without
extra hops through the stack or userspace.

So in order to fix this case add skb_adjust_room() so users can strip the
header. After this the user can strip the header and an unmodified receiver
thread will work correctly when data is redirected into the ingress path
of a sock.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/160160099197.7052.8443193973242831692.stgit@john-Precision-5820-Tower

Hao Luo says:

====================
v3 -> v4:
 - Rebasing
 - Cast bpf_[per|this]_cpu_ptr's parameter to void __percpu * before
   passing into per_cpu_ptr.

v2 -> v3:
 - Rename functions and variables in verifier for better readability.
 - Stick to logging message convention in libbpf.
 - Move bpf_per_cpu_ptr and bpf_this_cpu_ptr from trace-specific
   helper set to base helper set.
 - More specific test in ksyms_btf.
 - Fix return type cast in bpf_*_cpu_ptr.
 - Fix btf leak in ksyms_btf selftest.
 - Fix return error code for kallsyms_find().

v1 -> v2:
 - Move check_pseudo_btf_id from check_ld_imm() to
   replace_map_fd_with_map_ptr() and rename the latter.
 - Add bpf_this_cpu_ptr().
 - Use bpf_core_types_are_compat() in libbpf.c for checking type
   compatibility.
 - Rewrite typed ksym extern type in BTF with int to save space.
 - Minor revision of bpf_per_cpu_ptr()'s comments.
 - Avoid using long in tests that use skeleton.
 - Refactored test_ksyms.c by moving kallsyms_find() to trace_helpers.c
 - Fold the patches that sync include/linux/uapi and
   tools/include/linux/uapi.

rfc -> v1:
 - Encode VAR's btf_id for PSEUDO_BTF_ID.
 - More checks in verifier. Checking the btf_id passed as
   PSEUDO_BTF_ID is valid VAR, its name and type.
 - Checks in libbpf on type compatibility of ksyms.
 - Add bpf_per_cpu_ptr() to access kernel percpu vars. Introduced
   new ARG and RET types for this helper.

This patch series extends the previously added __ksym externs with
btf support.

Right now the __ksym externs are treated as pure 64-bit scalar value.
Libbpf replaces ld_imm64 insn of __ksym by its kernel address at load
time. This patch series extend those externs with their btf info. Note
that btf support for __ksym must come with the kernel btf that has
VARs encoded to work properly. The corresponding chagnes in pahole
is available at [1] (with a fix at [2] for gcc 4.9+).

The first 3 patches in this series add support for general kernel
global variables, which include verifier checking (01/06), libpf
support (02/06) and selftests for getting typed ksym extern's kernel
address (03/06).

The next 3 patches extends that capability further by introducing
helpers bpf_per_cpu_ptr() and bpf_this_cpu_ptr(), which allows accessing
kernel percpu variables correctly (04/06 and 05/06).

The tests of this feature were performed against pahole that is extended
with [1] and [2]. For kernel BTF that does not have VARs encoded, the
selftests will be skipped.

[1] https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=f3d9054ba8ff1df0fc44e507e3a01c0964cabd42
[2] https://www.spinics.net/lists/dwarves/msg00451.html


====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Test bpf_per_cpu_ptr() and bpf_this_cpu_ptr(). Test two paths in the
kernel. If the base pointer points to a struct, the returned reg is
of type PTR_TO_BTF_ID. Direct pointer dereference can be applied on
the returned variable. If the base pointer isn't a struct, the
returned reg is of type PTR_TO_MEM, which also supports direct pointer
dereference.

Signed-off-by: Hao Luo <haoluo@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200929235049.2533242-7-haoluo@google.com

Add bpf_this_cpu_ptr() to help access percpu var on this cpu. This
helper always returns a valid pointer, therefore no need to check
returned value for NULL. Also note that all programs run with
preemption disabled, which means that the returned pointer is stable
during all the execution of the program.

Signed-off-by: Hao Luo <haoluo@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200929235049.2533242-6-haoluo@google.com

Add bpf_per_cpu_ptr() to help bpf programs access percpu vars.
bpf_per_cpu_ptr() has the same semantic as per_cpu_ptr() in the kernel
except that it may return NULL. This happens when the cpu parameter is
out of range. So the caller must check the returned value.

Signed-off-by: Hao Luo <haoluo@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200929235049.2533242-5-haoluo@google.com

Selftests for typed ksyms. Tests two types of ksyms: one is a struct,
the other is a plain int. This tests two paths in the kernel. Struct
ksyms will be converted into PTR_TO_BTF_ID by the verifier while int
typed ksyms will be converted into PTR_TO_MEM.

Signed-off-by: Hao Luo <haoluo@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200929235049.2533242-4-haoluo@google.com

If a ksym is defined with a type, libbpf will try to find the ksym's btf
information from kernel btf. If a valid btf entry for the ksym is found,
libbpf can pass in the found btf id to the verifier, which validates the
ksym's type and value.

Typeless ksyms (i.e. those defined as 'void') will not have such btf_id,
but it has the symbol's address (read from kallsyms) and its value is
treated as a raw pointer.

Signed-off-by: Hao Luo <haoluo@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200929235049.2533242-3-haoluo@google.com

Pseudo_btf_id is a type of ld_imm insn that associates a btf_id to a
ksym so that further dereferences on the ksym can use the BTF info
to validate accesses. Internally, when seeing a pseudo_btf_id ld insn,
the verifier reads the btf_id stored in the insn[0]'s imm field and
marks the dst_reg as PTR_TO_BTF_ID. The btf_id points to a VAR_KIND,
which is encoded in btf_vminux by pahole. If the VAR is not of a struct
type, the dst reg will be marked as PTR_TO_MEM instead of PTR_TO_BTF_ID
and the mem_size is resolved to the size of the VAR's type.

>From the VAR btf_id, the verifier can also read the address of the
ksym's corresponding kernel var from kallsyms and use that to fill
dst_reg.

Therefore, the proper functionality of pseudo_btf_id depends on (1)
kallsyms and (2) the encoding of kernel global VARs in pahole, which
should be available since pahole v1.18.

Signed-off-by: Hao Luo <haoluo@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200929235049.2533242-2-haoluo@google.com

Martin KaFai says:

====================
This set fixes an issue that the bpf_skops_init_child() unnecessarily
limited the child sk from inheriting all bpf_sock_ops_cb_flags
of the listen sk.  It also adds a test to check that.
====================

Tested-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

This patch adds a test to ensure the child sk inherited everything
from the bpf_sock_ops_cb_flags of the listen sk:
1. Sets one more cb_flags (BPF_SOCK_OPS_STATE_CB_FLAG) to the listen sk
   in test_tcp_hdr_options.c
2. Saves the skops->bpf_sock_ops_cb_flags when handling the newly
   established passive connection
3. CHECK() it is the same as the listen sk

This also covers the fastopen case as the existing test_tcp_hdr_options.c
does.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201002013454.2542367-1-kafai@fb.com

The commit 0813a841 ("bpf: tcp: Allow bpf prog to write and parse TCP header option")
unnecessarily introduced bpf_skops_init_child() which limited the child
sk from inheriting all bpf_sock_ops_cb_flags of the listen sk.  That
breaks existing user expectation.

This patch removes the bpf_skops_init_child() and just allows
sock_copy() to do its job to copy everything from listen sk to
the child sk.

Fixes: 0813a841

 ("bpf: tcp: Allow bpf prog to write and parse TCP header option")
Reported-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201002013448.2542025-1-kafai@fb.com

When using -Werror=missing-braces, compiler complains about missing braces.
Let's use use ={} initialization which should do the job:

tools/testing/selftests/bpf/prog_tests/sockmap_basic.c: In function 'test_sockmap_iter':
tools/testing/selftests/bpf/prog_tests/sockmap_basic.c:181:8: error: missing braces around initializer [-Werror=missing-braces]
  union bpf_iter_link_info linfo = {0};
        ^
tools/testing/selftests/bpf/prog_tests/sockmap_basic.c:181:8: error: (near initialization for 'linfo.map') [-Werror=missing-braces]
tools/testing/selftests/bpf/prog_tests/sockmap_basic.c: At top level:

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20201002000451.1794044-1-sdf@google.com

Fixes clang error:
tools/testing/selftests/bpf/prog_tests/xdp_noinline.c:35:6: error: variable 'duration' is uninitialized when used here [-Werror,-Wuninitialized]
        if (CHECK(!skel, "skel_open_and_load", "failed\n"))
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20201001225440.1373233-1-sdf@google.com

Use netif_msg_init() to process param settings
and use only the proper initialized value of
ei_local->msg_level for later processing;

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Realtek single-chip Ethernet PHY solutions can be separated as below:
10M/100Mbps: RTL8201X
1Gbps: RTL8211X
2.5Gbps: RTL8226/RTL8221X
RTL8226 is the first version for realtek that compatible 2.5Gbps single PHY.
Since RTL8226 is single port only, realtek changes its name to RTL8221B from
the second version.
PHY ID for RTL8226 is 0x001cc800 and RTL8226B/RTL8221B is 0x001cc840.

RTL8125 is not a single PHY solution, it integrates PHY/MAC/PCIE bus
controller and embedded memory.

Signed-off-by: Willy Liu <willy.liu@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

After commit a8c7687b

 ("caif_virtio: Check that vringh_config is not
null"), the variable err is being initialized with '-EINVAL' that is
meaningless. So remove it.

Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix follow warnings:
[net/core/net-sysfs.c:1161]: (warning) %u in format string (no. 1)
	requires 'unsigned int' but the argument type is 'int'.
[net/core/net-sysfs.c:1162]: (warning) %u in format string (no. 1)
	requires 'unsigned int' but the argument type is 'int'.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Ye Bin <yebin10@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix follow warnings:
[net/core/pktgen.c:925]: (warning) %u in format string (no. 1)
	requires 'unsigned int' but the argument type is 'signed int'.
[net/core/pktgen.c:942]: (warning) %u in format string (no. 1)
	requires 'unsigned int' but the argument type is 'signed int'.
[net/core/pktgen.c:962]: (warning) %u in format string (no. 1)
	requires 'unsigned int' but the argument type is 'signed int'.
[net/core/pktgen.c:984]: (warning) %u in format string (no. 1)
	requires 'unsigned int' but the argument type is 'signed int'.
[net/core/pktgen.c:1149]: (warning) %d in format string (no. 1)
	requires 'int' but the argument type is 'unsigned int'.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Ye Bin <yebin10@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The fr_hard_header function is used to prepend the header to skbs before
transmission. It is used in 3 situations:
1) When a control packet is generated internally in this driver;
2) When a user sends an skb on an Ethernet-emulating PVC device;
3) When a user sends an skb on a normal PVC device.

These 3 situations need to be handled differently by fr_hard_header.
Different headers should be prepended to the skb in different situations.

Currently fr_hard_header distinguishes these 3 situations using
skb->protocol. For situation 1 and 2, a special skb->protocol value
will be assigned before calling fr_hard_header, so that it can recognize
these 2 situations. All skb->protocol values other than these special ones
are treated by fr_hard_header as situation 3.

However, it is possible that in situation 3, the user sends an skb with
one of the special skb->protocol values. In this case, fr_hard_header
would incorrectly treat it as situation 1 or 2.

This patch tries to solve this issue by using skb->dev instead of
skb->protocol to distinguish between these 3 situations. For situation
1, skb->dev would be NULL; for situation 2, skb->dev->type would be
ARPHRD_ETHER; and for situation 3, skb->dev->type would be ARPHRD_DLCI.

This way fr_hard_header would be able to distinguish these 3 situations
correctly regardless what skb->protocol value the user tries to use in
situation 3.

Cc: Krzysztof Halasa <khc@pm.waw.pl>
Signed-off-by: Xie He <xie.he.0141@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Daniel Borkmann says:

====================
pull-request: bpf-next 2020-10-01

The following pull-request contains BPF updates for your *net-next* tree.

We've added 90 non-merge commits during the last 8 day(s) which contain
a total of 103 files changed, 7662 insertions(+), 1894 deletions(-).

Note that once bpf(/net) tree gets merged into net-next, there will be a small
merge conflict in tools/lib/bpf/btf.c between commit 12450081 ("libbpf: Fix
native endian assumption when parsing BTF") from the bpf tree and the commit
3289959b ("libbpf: Support BTF loading and raw data output in both endianness")
from the bpf-next tree. Correct resolution would be to stick with bpf-next, it
should look like:

  [...]
        /* check BTF magic */
        if (fread(&magic, 1, sizeof(magic), f) < sizeof(magic)) {
                err = -EIO;
                goto err_out;
        }
        if (magic != BTF_MAGIC && magic != bswap_16(BTF_MAGIC)) {
   ...