All these operations are isomorphic enough to implement with the same
verifier, interpreter, and x86 JIT code, hence being a single commit.
The main interesting thing here is that x86 doesn't directly support
the fetch_ version these operations, so we need to generate a CMPXCHG
loop in the JIT. This requires the use of two temporary registers,
IIUC it's safe to use BPF_REG_AX and x86's AUX_REG for this purpose.
Brendan Jackman [Thu, 14 Jan 2021 18:17:48 +0000 (18:17 +0000)]
bpf: Pull out a macro for interpreting atomic ALU operations
Since the atomic operations that are added in subsequent commits are
all isomorphic with BPF_ADD, pull out a macro to avoid the
interpreter becoming dominated by lines of atomic-related code.
Note that this sacrificies interpreter performance (combining
STX_ATOMIC_W and STX_ATOMIC_DW into single switch case means that we
need an extra conditional branch to differentiate them) in favour of
compact and (relatively!) simple C code.
Brendan Jackman [Thu, 14 Jan 2021 18:17:47 +0000 (18:17 +0000)]
bpf: Add instructions for atomic_[cmp]xchg
This adds two atomic opcodes, both of which include the BPF_FETCH
flag. XCHG without the BPF_FETCH flag would naturally encode
atomic_set. This is not supported because it would be of limited
value to userspace (it doesn't imply any barriers). CMPXCHG without
BPF_FETCH woulud be an atomic compare-and-write. We don't have such
an operation in the kernel so it isn't provided to BPF either.
There are two significant design decisions made for the CMPXCHG
instruction:
- To solve the issue that this operation fundamentally has 3
operands, but we only have two register fields. Therefore the
operand we compare against (the kernel's API calls it 'old') is
hard-coded to be R0. x86 has similar design (and A64 doesn't
have this problem).
A potential alternative might be to encode the other operand's
register number in the immediate field.
- The kernel's atomic_cmpxchg returns the old value, while the C11
userspace APIs return a boolean indicating the comparison
result. Which should BPF do? A64 returns the old value. x86 returns
the old value in the hard-coded register (and also sets a
flag). That means return-old-value is easier to JIT, so that's
what we use.
Brendan Jackman [Thu, 14 Jan 2021 18:17:46 +0000 (18:17 +0000)]
bpf: Add BPF_FETCH field / create atomic_fetch_add instruction
The BPF_FETCH field can be set in bpf_insn.imm, for BPF_ATOMIC
instructions, in order to have the previous value of the
atomically-modified memory location loaded into the src register
after an atomic op is carried out.
Brendan Jackman [Thu, 14 Jan 2021 18:17:44 +0000 (18:17 +0000)]
bpf: Rename BPF_XADD and prepare to encode other atomics in .imm
A subsequent patch will add additional atomic operations. These new
operations will use the same opcode field as the existing XADD, with
the immediate discriminating different operations.
In preparation, rename the instruction mode BPF_ATOMIC and start
calling the zero immediate BPF_ADD.
This is possible (doesn't break existing valid BPF progs) because the
immediate field is currently reserved MBZ and BPF_ADD is zero.
All uses are removed from the tree but the BPF_XADD definition is
kept around to avoid breaking builds for people including kernel
headers.
Brendan Jackman [Thu, 14 Jan 2021 18:17:42 +0000 (18:17 +0000)]
bpf: x86: Factor out emission of REX byte
The JIT case for encoding atomic ops is about to get more
complicated. In order to make the review & resulting code easier,
let's factor out some shared helpers.
Ian Rogers [Wed, 13 Jan 2021 22:36:08 +0000 (14:36 -0800)]
bpf, libbpf: Avoid unused function warning on bpf_tail_call_static
Add inline to __always_inline making it match the linux/compiler.h.
Adding this avoids an unused function warning on bpf_tail_call_static
when compining with -Wall.
selftests/bpf: Move generated test files to $(TEST_GEN_FILES)
During an out-of-tree build, attempting to install the $(TEST_FILES)
into the $(OUTPUT) directory fails, because the objects were already
generated into $(OUTPUT):
rsync: [sender] link_stat "tools/testing/selftests/bpf/test_lwt_ip_encap.o" failed: No such file or directory (2)
rsync: [sender] link_stat "tools/testing/selftests/bpf/test_tc_edt.o" failed: No such file or directory (2)
Build bpftool and resolve_btfids using the host toolchain when
cross-compiling, since they are executed during build to generate the
selftests. Add a host build directory in order to build both host and
target version of libbpf. Build host tools using $(HOSTCC) defined in
Makefile.include.
Add support for using kernel module global variables (__ksym externs in BPF
program). BPF verifier will now support ldimm64 with src_reg=BPF_PSEUDO_BTF_ID
and non-zero insn[1].imm field, specifying module BTF's FD. In such case,
module BTF object, similarly to BPF maps referenced from ldimm64 with
src_reg=BPF_PSEUDO_MAP_FD, will be recorded in bpf_progran's auxiliary data
and refcnt will be increased for both BTF object itself and its kernel module.
This makes sure kernel module won't be unloaded from under active attached BPF
program. These refcounts will be dropped when BPF program is unloaded.
New selftest validates all this is working as intended. bpf_testmod.ko is
extended with per-CPU variable. Selftests expects the latest pahole changes
(soon to be released as v1.20) to generate per-CPU variable BTF info for
kernel module.
v2->v3:
- added comments, addressed feedack (Yonghong, Hao);
v1->v2:
- fixed few compiler warnings, posted as separate pre-patches;
rfc->v1:
- use sys_membarrier(MEMBARRIER_CMD_GLOBAL) (Alexei).
Cc: Hao Luo <haoluo@google.com>
====================
Andrii Nakryiko [Tue, 12 Jan 2021 07:55:19 +0000 (23:55 -0800)]
libbpf: Support kernel module ksym externs
Add support for searching for ksym externs not just in vmlinux BTF, but across
all module BTFs, similarly to how it's done for CO-RE relocations. Kernels
that expose module BTFs through sysfs are assumed to support new ldimm64
instruction extension with BTF FD provided in insn[1].imm field, so no extra
feature detection is performed.
Andrii Nakryiko [Tue, 12 Jan 2021 07:55:18 +0000 (23:55 -0800)]
bpf: Support BPF ksym variables in kernel modules
Add support for directly accessing kernel module variables from BPF programs
using special ldimm64 instructions. This functionality builds upon vmlinux
ksym support, but extends ldimm64 with src_reg=BPF_PSEUDO_BTF_ID to allow
specifying kernel module BTF's FD in insn[1].imm field.
During BPF program load time, verifier will resolve FD to BTF object and will
take reference on BTF object itself and, for module BTFs, corresponding module
as well, to make sure it won't be unloaded from under running BPF program. The
mechanism used is similar to how bpf_prog keeps track of used bpf_maps.
One interesting change is also in how per-CPU variable is determined. The
logic is to find .data..percpu data section in provided BTF, but both vmlinux
and module each have their own .data..percpu entries in BTF. So for module's
case, the search for DATASEC record needs to look at only module's added BTF
types. This is implemented with custom search function.
Andrii Nakryiko [Tue, 12 Jan 2021 07:55:17 +0000 (23:55 -0800)]
selftests/bpf: Sync RCU before unloading bpf_testmod
If some of the subtests use module BTFs through ksyms, they will cause
bpf_prog to take a refcount on bpf_testmod module, which will prevent it from
successfully unloading. Module's refcnt is decremented when bpf_prog is freed,
which generally happens in RCU callback. So we need to trigger
syncronize_rcu() in the kernel, which can be achieved nicely with
membarrier(MEMBARRIER_CMD_SHARED) or membarrier(MEMBARRIER_CMD_GLOBAL) syscall.
So do that in kernel_sync_rcu() and make it available to other test inside the
test_progs. This synchronize_rcu() is called before attempting to unload
bpf_testmod.
__bpf_free_used_maps() is always defined in kernel/bpf/core.c, while
include/linux/bpf.h is guarding it behind CONFIG_BPF_SYSCALL. Move it out of
that guard region and fix compiler warning.
Fixes: 1749b0f2486c ("bpf: Fix missing prog untrack in release_maps") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20210112075520.4103414-4-andrii@kernel.org
Andrii Nakryiko [Tue, 12 Jan 2021 07:55:15 +0000 (23:55 -0800)]
bpf: Avoid warning when re-casting __bpf_call_base into __bpf_call_base_args
BPF interpreter uses extra input argument, so re-casts __bpf_call_base into
__bpf_call_base_args. Avoid compiler warning about incompatible function
prototypes by casting to void * first.
Fixes: c66d5170f273 ("bpf: add support for bpf_call to interpreter") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20210112075520.4103414-3-andrii@kernel.org
Andrii Nakryiko [Tue, 12 Jan 2021 07:55:14 +0000 (23:55 -0800)]
bpf: Add bpf_patch_call_args prototype to include/linux/bpf.h
Add bpf_patch_call_args() prototype. This function is called from BPF verifier
and only if CONFIG_BPF_JIT_ALWAYS_ON is not defined. This fixes compiler
warning about missing prototype in some kernel configurations.
Fixes: c66d5170f273 ("bpf: add support for bpf_call to interpreter") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20210112075520.4103414-2-andrii@kernel.org
Daniel Borkmann [Mon, 11 Jan 2021 23:09:39 +0000 (00:09 +0100)]
bpf: Allow to retrieve sol_socket opts from sock_addr progs
The _bpf_setsockopt() is able to set some of the SOL_SOCKET level options,
however, _bpf_getsockopt() has little support to actually retrieve them.
This small patch adds few misc options such as SO_MARK, SO_PRIORITY and
SO_BINDTOIFINDEX. For the latter getter and setter are added. The mark and
priority in particular allow to retrieve the options from BPF cgroup hooks
to then implement custom behavior / settings on the syscall hooks compared
to other sockets that stick to the defaults, for example.
Brendan Jackman [Tue, 12 Jan 2021 12:34:22 +0000 (12:34 +0000)]
bpf: Clarify return value of probe str helpers
When the buffer is too small to contain the input string, these helpers
return the length of the buffer, not the length of the original string.
This tries to make the docs totally clear about that, since "the length
of the [copied ]string" could also refer to the length of the input.
Andrii Nakryiko [Fri, 8 Jan 2021 19:44:08 +0000 (11:44 -0800)]
libbpf: Clarify kernel type use with USER variants of CORE reading macros
Add comments clarifying that USER variants of CO-RE reading macro are still
only going to work with kernel types, defined in kernel or kernel module BTF.
This should help preventing invalid use of those macro to read user-defined
types (which doesn't work with CO-RE).
Introduce xdp_prepare_buff utility routine to initialize per-descriptor
xdp_buff fields (e.g. xdp_buff pointers). Rely on xdp_prepare_buff() in
all XDP capable drivers.
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Alexander Duyck <alexanderduyck@fb.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Shay Agroskin <shayagr@amazon.com> Acked-by: Martin Habets <habetsm.xilinx@gmail.com> Acked-by: Camelia Groza <camelia.groza@nxp.com> Acked-by: Marcin Wojtas <mw@semihalf.com> Link: https://lore.kernel.org/bpf/45f46f12295972a97da8ca01990b3e71501e9d89.1608670965.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Lorenzo Bianconi [Tue, 22 Dec 2020 21:09:28 +0000 (22:09 +0100)]
net, xdp: Introduce xdp_init_buff utility routine
Introduce xdp_init_buff utility routine to initialize xdp_buff fields
const over NAPI iterations (e.g. frame_sz or rxq pointer). Rely on
xdp_init_buff in all XDP capable drivers.
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Alexander Duyck <alexanderduyck@fb.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Shay Agroskin <shayagr@amazon.com> Acked-by: Martin Habets <habetsm.xilinx@gmail.com> Acked-by: Camelia Groza <camelia.groza@nxp.com> Acked-by: Marcin Wojtas <mw@semihalf.com> Link: https://lore.kernel.org/bpf/7f8329b6da1434dc2b05a77f2e800b29628a8913.1608670965.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Zheng Yongjun [Tue, 29 Dec 2020 13:48:34 +0000 (21:48 +0800)]
bpf: Replace fput with sockfd_put in sock map
The function sockfd_lookup uses fget on the value that is stored in
the file field of the returned structure, so fput should ultimately
be applied to this value. This can be done directly, but it seems
better to use the specific macro sockfd_put, which does the same
thing.
The cleanup was done using the following semantic patch:
(http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@@
expression s;
@@
s = sockfd_lookup(...)
...
+ sockfd_put(s);
?- fput(s->file);
// </smpl>
Andrii Nakryiko [Fri, 18 Dec 2020 23:56:13 +0000 (15:56 -0800)]
libbpf: Add non-CO-RE variants of BPF_CORE_READ() macro family
BPF_CORE_READ(), in addition to handling CO-RE relocations, also allows much
nicer way to read data structures with nested pointers. Instead of writing
a sequence of bpf_probe_read() calls to follow links, one can just write
BPF_CORE_READ(a, b, c, d) to effectively do a->b->c->d read. This is a welcome
ability when porting BCC code, which (in most cases) allows exactly the
intuitive a->b->c->d variant.
This patch adds non-CO-RE variants of BPF_CORE_READ() family of macros for
cases where CO-RE is not supported (e.g., old kernels). In such cases, the
property of shortening a sequence of bpf_probe_read()s to a simple
BPF_PROBE_READ(a, b, c, d) invocation is still desirable, especially when
porting BCC code to libbpf. Yet, no CO-RE relocation is going to be emitted.
Andrii Nakryiko [Fri, 18 Dec 2020 23:56:12 +0000 (15:56 -0800)]
libbpf: Add user-space variants of BPF_CORE_READ() family of macros
Add BPF_CORE_READ_USER(), BPF_CORE_READ_USER_STR() and their _INTO()
variations to allow reading CO-RE-relocatable kernel data structures from the
user-space. One of such cases is reading input arguments of syscalls, while
reaping the benefits of CO-RE relocations w.r.t. handling 32/64 bit
conversions and handling missing/new fields in UAPI data structs.
Suggested-by: Gilad Reti <gilad.reti@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20201218235614.2284956-2-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Linus Torvalds [Fri, 8 Jan 2021 20:12:30 +0000 (12:12 -0800)]
Merge tag 'net-5.11-rc3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull more networking fixes from Jakub Kicinski:
"Slightly lighter pull request to get back into the Thursday cadence.
Current release - always broken:
- can: mcp251xfd: fix Tx/Rx ring buffer driver race conditions
- dsa: hellcreek: fix led_classdev build errors
Previous releases - regressions:
- ipv6: fib: flush exceptions when purging route to avoid netdev
reference leak
- ip_tunnels: fix pmtu check in nopmtudisc mode
- ip: always refragment ip defragmented packets to avoid MTU issues
when forwarding through tunnels, correct "packet too big" message
is prohibitively tricky to generate
- s390/qeth: fix locking for discipline setup / removal and during
recovery to prevent both deadlocks and races
- mlx5: Use port_num 1 instead of 0 when delete a RoCE address
Previous releases - always broken:
- cdc_ncm: correct overhead calculation in delayed_ndp_size to
prevent out of bound accesses with Huawei 909s-120 LTE module
- fix stmmac dwmac-sun8i suspend/resume:
- PHY being left powered off
- MAC syscon configuration being reset
- reference to the reset controller being improperly dropped
- qrtr: fix null-ptr-deref in qrtr_ns_remove
- can: tcan4x5x: fix bittiming const, use common bittiming from m_can
driver
- mlx5e: CT: Use per flow counter when CT flow accounting is enabled
- mlx5e: Fix SWP offsets when vlan inserted by driver
Misc:
- bpf: Fix a task_iter bug caused by a bpf -> net merge conflict
resolution
And the usual many fixes to various error paths"
* tag 'net-5.11-rc3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (69 commits)
net: dsa: lantiq_gswip: Exclude RMII from modes that report 1 GbE
s390/qeth: fix L2 header access in qeth_l3_osa_features_check()
s390/qeth: fix locking for discipline setup / removal
s390/qeth: fix deadlock during recovery
selftests: fib_nexthops: Fix wrong mausezahn invocation
nexthop: Bounce NHA_GATEWAY in FDB nexthop groups
nexthop: Unlink nexthop group entry in error path
nexthop: Fix off-by-one error in error path
octeontx2-af: fix memory leak of lmac and lmac->name
chtls: Fix chtls resources release sequence
chtls: Added a check to avoid NULL pointer dereference
chtls: Replace skb_dequeue with skb_peek
chtls: Avoid unnecessary freeing of oreq pointer
chtls: Fix panic when route to peer not configured
chtls: Remove invalid set_tcb call
chtls: Fix hardware tid leak
net: ip: always refragment ip defragmented packets
net: fix pmtu check in nopmtudisc mode
selftests: netfilter: add selftest for ipip pmtu discovery with enabled connection tracking
docs: octeontx2: tune rst markup
...
Linus Torvalds [Thu, 7 Jan 2021 17:43:54 +0000 (09:43 -0800)]
poll: fix performance regression due to out-of-line __put_user()
The kernel test robot reported a -5.8% performance regression on the
"poll2" test of will-it-scale, and bisected it to commit 90ecb7b4941f
("x86: Make __put_user() generate an out-of-line call").
I didn't expect an out-of-line __put_user() to matter, because no normal
core code should use that non-checking legacy version of user access any
more. But I had overlooked the very odd poll() usage, which does a
__put_user() to update the 'revents' values of the poll array.
Now, Al Viro correctly points out that instead of updating just the
'revents' field, it would be much simpler to just copy the _whole_
pollfd entry, and then we could just use "copy_to_user()" on the whole
array of entries, the same way we use "copy_from_user()" a few lines
earlier to get the original values.
But that is not what we've traditionally done, and I worry that threaded
applications might be concurrently modifying the other fields of the
pollfd array. So while Al's suggestion is simpler - and perhaps worth
trying in the future - this instead keeps the "just update revents"
model.
To fix the performance regression, use the modern "unsafe_put_user()"
instead of __put_user(), with the proper "user_write_access_begin()"
guarding in place. This improves code generation enormously.
Link: https://lore.kernel.org/lkml/20210107134723.GA28532@xsang-OptiPlex-9020/ Reported-by: kernel test robot <oliver.sang@intel.com> Tested-by: Oliver Sang <oliver.sang@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: David Laight <David.Laight@aculab.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The commit caused that ttynull was used as the default console
on several systems[1][2][3]. As a result, the console was
blank even when a better alternative existed.
It happened when there was no console configured
on the command line and ttynull_init() was the first initcall
calling register_console().
Or it happened when /dev/ did not exist when console_on_rootfs()
was called. It was not able to open /dev/console even though
a console driver was registered. It tried to add ttynull console
but it obviously did not help. But ttynull became the preferred
console and was used by /dev/console when it was available later.
The commit tried to fix a historical problem that have been there
for ages. The primary motivation was the commit 6e2c2274f6d4661ea78
("printk/console: Allow to disable console output by using console=""
or console=null"). It provided a clean solution for a workaround
that was widely used and worked only by chance.
This revert causes that the console="" or console=null command line
options will again work only by chance. These options will cause that
a particular console will be preferred and the default (tty) ones
will not get enabled. There will be no console registered at
all. As a result there won't be stdin, stdout, and stderr for
the init process. But it worked exactly this way even before.
The proper solution has to fulfill many conditions:
+ Register ttynull only when explicitly required or as
the ultimate fallback.
+ ttynull should get associated with /dev/console but it must
not become preferred console when used as a fallback.
Especially, it must still be possible to replace it
by a better console later.
Such a change requires clean up of the register_console() code.
Otherwise, it would be even harder to follow. Especially, the use
of has_preferred_console and CON_CONSDEV flag is tricky. The clean
up is risky. The ordering of consoles is not well defined. And
any changes tend to break existing user settings.
Do the revert at the least risky solution for now.
Jakub Kicinski [Fri, 8 Jan 2021 03:13:29 +0000 (19:13 -0800)]
Merge tag 'mlx5-fixes-2021-01-07' of git://git.kernel.org/pub/scm/linux/kernel/git/saeed/linux
Saeed Mahameed says:
====================
mlx5 fixes 2021-01-07
* tag 'mlx5-fixes-2021-01-07' of git://git.kernel.org/pub/scm/linux/kernel/git/saeed/linux:
net/mlx5e: Fix memleak in mlx5e_create_l2_table_groups
net/mlx5e: Fix two double free cases
net/mlx5: Release devlink object if adev fails
net/mlx5e: ethtool, Fix restriction of autoneg with 56G
net/mlx5e: In skb build skip setting mark in switchdev mode
net/mlx5: E-Switch, fix changing vf VLANID
net/mlx5e: Fix SWP offsets when vlan inserted by driver
net/mlx5e: CT: Use per flow counter when CT flow accounting is enabled
net/mlx5: Use port_num 1 instead of 0 when delete a RoCE address
net/mlx5e: Add missing capability check for uplink follow
net/mlx5: Check if lag is supported before creating one
====================
Jakub Kicinski [Fri, 8 Jan 2021 02:54:08 +0000 (18:54 -0800)]
Merge branch 's390-qeth-fixes-2021-01-07'
Julian Wiedmann says:
====================
s390/qeth: fixes 2021-01-07
This brings two locking fixes for the device control path.
Also one fix for a path where our .ndo_features_check() attempts to
access a non-existent L2 header.
====================
Julian Wiedmann [Thu, 7 Jan 2021 17:24:42 +0000 (18:24 +0100)]
s390/qeth: fix L2 header access in qeth_l3_osa_features_check()
ip_finish_output_gso() may call .ndo_features_check() even before the
skb has a L2 header. This conflicts with qeth_get_ip_version()'s attempt
to inspect the L2 header via vlan_eth_hdr().
Switch to vlan_get_protocol(), as already used further down in the
common qeth_features_check() path.
Fixes: 22ea4cac8dc7 ("s390/qeth: run non-offload L3 traffic over common xmit path") Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Julian Wiedmann [Thu, 7 Jan 2021 17:24:41 +0000 (18:24 +0100)]
s390/qeth: fix locking for discipline setup / removal
Due to insufficient locking, qeth_core_set_online() and
qeth_dev_layer2_store() can run in parallel, both attempting to load &
setup the discipline (and stepping on each other toes along the way).
A similar race can also occur between qeth_core_remove_device() and
qeth_dev_layer2_store().
Access to .discipline is meant to be protected by the discipline_mutex,
so add/expand the locking in qeth_core_remove_device() and
qeth_core_set_online().
Adjust the locking in qeth_l*_remove_device() accordingly, as it's now
handled by the callers in a consistent manner.
Based on an initial patch by Ursula Braun.
Fixes: 5ade8c676c59 ("qeth: serialize sysfs-triggered device configurations") Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Reviewed-by: Alexandra Winter <wintera@linux.ibm.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Julian Wiedmann [Thu, 7 Jan 2021 17:24:40 +0000 (18:24 +0100)]
s390/qeth: fix deadlock during recovery
When qeth_dev_layer2_store() - holding the discipline_mutex - waits
inside qeth_l*_remove_device() for a qeth_do_reset() thread to complete,
we can hit a deadlock if qeth_do_reset() concurrently calls
qeth_set_online() and thus tries to aquire the discipline_mutex.
Move the discipline_mutex locking outside of qeth_set_online() and
qeth_set_offline(), and turn the discipline into a parameter so that
callers understand the dependency.
To fix the deadlock, we can now relax the locking:
As already established, qeth_l*_remove_device() waits for
qeth_do_reset() to complete. So qeth_do_reset() itself is under no risk
of having card->discipline ripped out while it's running, and thus
doesn't need to take the discipline_mutex.
Fixes: 5ade8c676c59 ("qeth: serialize sysfs-triggered device configurations") Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Reviewed-by: Alexandra Winter <wintera@linux.ibm.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Jakub Kicinski [Fri, 8 Jan 2021 02:47:21 +0000 (18:47 -0800)]
Merge branch 'nexthop-various-fixes'
Ido Schimmel says:
====================
nexthop: Various fixes
This series contains various fixes for the nexthop code. The bugs were
uncovered during the development of resilient nexthop groups.
Patches #1-#2 fix the error path of nexthop_create_group(). I was not
able to trigger these bugs with current code, but it is possible with
the upcoming resilient nexthop groups code which adds a user
controllable memory allocation further in the function.
Patch #3 fixes wrong validation of netlink attributes.
Patch #4 fixes wrong invocation of mausezahn in a selftest.
====================
For IPv6 traffic, mausezahn needs to be invoked with '-6'. Otherwise an
error is returned:
# ip netns exec me mausezahn veth1 -B 2001:db8:101::2 -A 2001:db8:91::1 -c 0 -t tcp "dp=1-1023, flags=syn"
Failed to set source IPv4 address. Please check if source is set to a valid IPv4 address.
Invalid command line parameters!
Fixes: 7fd6561585bc ("selftests: Add torture tests to nexthop tests") Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Petr Machata <petrm@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Petr Machata [Thu, 7 Jan 2021 14:48:23 +0000 (16:48 +0200)]
nexthop: Bounce NHA_GATEWAY in FDB nexthop groups
The function nh_check_attr_group() is called to validate nexthop groups.
The intention of that code seems to have been to bounce all attributes
above NHA_GROUP_TYPE except for NHA_FDB. However instead it bounces all
these attributes except when NHA_FDB attribute is present--then it accepts
them.
NHA_FDB validation that takes place before, in rtm_to_nh_config(), already
bounces NHA_OIF, NHA_BLACKHOLE, NHA_ENCAP and NHA_ENCAP_TYPE. Yet further
back, NHA_GROUPS and NHA_MASTER are bounced unconditionally.
But that still leaves NHA_GATEWAY as an attribute that would be accepted in
FDB nexthop groups (with no meaning), so long as it keeps the address
family as unspecified:
# ip nexthop add id 1 fdb via 127.0.0.1
# ip nexthop add id 10 fdb via default group 1
The nexthop code is still relatively new and likely not used very broadly,
and the FDB bits are newer still. Even though there is a reproducer out
there, it relies on an improbable gateway arguments "via default", "via
all" or "via any". Given all this, I believe it is OK to reformulate the
condition to do the right thing and bounce NHA_GATEWAY.
Fixes: 135a256ce034 ("nexthop: support for fdb ecmp nexthops") Signed-off-by: Petr Machata <petrm@nvidia.com> Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Ido Schimmel [Thu, 7 Jan 2021 14:48:22 +0000 (16:48 +0200)]
nexthop: Unlink nexthop group entry in error path
In case of error, remove the nexthop group entry from the list to which
it was previously added.
Fixes: 6e9d1ef54f91 ("nexthop: Add support for nexthop groups") Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Petr Machata <petrm@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Ido Schimmel [Thu, 7 Jan 2021 14:48:21 +0000 (16:48 +0200)]
nexthop: Fix off-by-one error in error path
A reference was not taken for the current nexthop entry, so do not try
to put it in the error path.
Fixes: 6e9d1ef54f91 ("nexthop: Add support for nexthop groups") Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Petr Machata <petrm@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Colin Ian King [Thu, 7 Jan 2021 12:39:16 +0000 (12:39 +0000)]
octeontx2-af: fix memory leak of lmac and lmac->name
Currently the error return paths don't kfree lmac and lmac->name
leading to some memory leaks. Fix this by adding two error return
paths that kfree these objects
Addresses-Coverity: ("Resource leak") Fixes: 457ca95f900f ("octeontx2-af: Add support for CGX link management") Signed-off-by: Colin Ian King <colin.king@canonical.com> Link: https://lore.kernel.org/r/20210107123916.189748-1-colin.king@canonical.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Ayush Sawal [Wed, 6 Jan 2021 04:29:12 +0000 (09:59 +0530)]
chtls: Fix chtls resources release sequence
CPL_ABORT_RPL is sent after releasing the resources by calling
chtls_release_resources(sk); and chtls_conn_done(sk);
eventually causing kernel panic. Fixing it by calling release
in appropriate order.
Ayush Sawal [Wed, 6 Jan 2021 04:29:10 +0000 (09:59 +0530)]
chtls: Replace skb_dequeue with skb_peek
The skb is unlinked twice, one in __skb_dequeue in function
chtls_reset_synq() and another in cleanup_syn_rcv_conn().
So in this patch using skb_peek() instead of __skb_dequeue(),
so that unlink will be handled only in cleanup_syn_rcv_conn().
Ayush Sawal [Wed, 6 Jan 2021 04:29:07 +0000 (09:59 +0530)]
chtls: Remove invalid set_tcb call
At the time of SYN_RECV, connection information is not
initialized at FW, updating tcb flag over uninitialized
connection causes adapter crash. We don't need to
update the flag during SYN_RECV state, so avoid this.
Ayush Sawal [Wed, 6 Jan 2021 04:29:06 +0000 (09:59 +0530)]
chtls: Fix hardware tid leak
send_abort_rpl() is not calculating cpl_abort_req_rss offset and
ends up sending wrong TID with abort_rpl WR causng tid leaks.
Replaced send_abort_rpl() with chtls_send_abort_rpl() as it is
redundant.
Jonathan Lemon [Wed, 6 Jan 2021 22:18:41 +0000 (14:18 -0800)]
skbuff: Rename skb_zcopy_{get|put} to net_zcopy_{get|put}
Unlike the rest of the skb_zcopy_ functions, these routines
operate on a 'struct ubuf', not a skb. Remove the 'skb_'
prefix from the naming to make things clearer.
Suggested-by: Willem de Bruijn <willemdebruijn.kernel@gmail.com> Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Jonathan Lemon [Wed, 6 Jan 2021 22:18:39 +0000 (14:18 -0800)]
skbuff: add flags to ubuf_info for ubuf setup
Currently, when an ubuf is attached to a new skb, the shared
flags word is initialized to a fixed value. Instead of doing
this, set the default flags in the ubuf, and have new skbs
inherit from this default.
This is needed when setting up different zerocopy types.
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Jonathan Lemon [Wed, 6 Jan 2021 22:18:37 +0000 (14:18 -0800)]
skbuff: rename sock_zerocopy_* to msg_zerocopy_*
At Willem's suggestion, rename the sock_zerocopy_* functions
so that they match the MSG_ZEROCOPY flag, which makes it clear
they are specific to this zerocopy implementation.
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Jonathan Lemon [Wed, 6 Jan 2021 22:18:36 +0000 (14:18 -0800)]
skbuff: Call skb_zcopy_clear() before unref'ing fragments
RX zerocopy fragment pages which are not allocated from the
system page pool require special handling. Give the callback
in skb_zcopy_clear() a chance to process them first.
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Jonathan Lemon [Wed, 6 Jan 2021 22:18:35 +0000 (14:18 -0800)]
skbuff: Call sock_zerocopy_put_abort from skb_zcopy_put_abort
The sock_zerocopy_put_abort function contains logic which is
specific to the current zerocopy implementation. Add a wrapper
which checks the callback and dispatches apppropriately.
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Jonathan Lemon [Wed, 6 Jan 2021 22:18:34 +0000 (14:18 -0800)]
skbuff: Add skb parameter to the ubuf zerocopy callback
Add an optional skb parameter to the zerocopy callback parameter,
which is passed down from skb_zcopy_clear(). This gives access
to the original skb, which is needed for upcoming RX zero-copy
error handling.
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Jonathan Lemon [Wed, 6 Jan 2021 22:18:31 +0000 (14:18 -0800)]
skbuff: Push status and refcounts into sock_zerocopy_callback
Before this change, the caller of sock_zerocopy_callback would
need to save the zerocopy status, decrement and check the refcount,
and then call the callback function - the callback was only invoked
when the refcount reached zero.
Now, the caller just passes the status into the callback function,
which saves the status and handles its own refcounts.
This makes the behavior of the sock_zerocopy_callback identical
to the tpacket and vhost callbacks.
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Jonathan Lemon [Wed, 6 Jan 2021 22:18:30 +0000 (14:18 -0800)]
skbuff: simplify sock_zerocopy_put
All 'struct ubuf_info' users should have a callback defined
as of commit b711e82a14ab ("sock: fix zerocopy_success regression
with msg_zerocopy").
Remove the dead code path to consume_skb(), which makes
assumptions about how the structure was allocated.
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Jonathan Lemon [Wed, 6 Jan 2021 22:18:29 +0000 (14:18 -0800)]
skbuff: remove unused skb_zcopy_abort function
skb_zcopy_abort() has no in-tree consumers, remove it.
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
====================
dwmac-meson8b: picosecond precision RX delay support
with the help of Jianxin Pan (many thanks!) the meaning of the "new"
PRG_ETH1[19:16] register bits on Amlogic Meson G12A, G12B and SM1 SoCs
are finally known. These SoCs allow fine-tuning the RGMII RX delay in
200ps steps (contrary to what I have thought in the past [0] these are
not some "calibration" values).
The vendor u-boot has code to automatically detect the best RX/TX delay
settings. For now we keep it simple and add a device-tree property with
200ps precision to select the "right" RX delay for each board.
While here, deprecate the "amlogic,rx-delay-ns" property as it's not
used on any upstream .dts (yet). The driver is backwards compatible.
I have tested this on an X96 Air 4GB board (not upstream yet). Testing
with iperf3 gives 938 Mbits/sec in both directions (RX and TX). The
following network settings were used in the .dts (2ns TX delay
generated by the PHY, 800ps RX delay generated by the MAC as the PHY
only supports 0ns or 2ns RX delays):
&ext_mdio {
external_phy: ethernet-phy@0 {
/* Realtek RTL8211F (0x001cc916) */
reg = <0>;
eee-broken-1000t;
To use the same settings from vendor u-boot (which in my case has broken
Ethernet) the following commands can be used:
mw.l 0xff634540 0x1621
mw.l 0xff634544 0x30000
phyreg w 0x0 0x1040
phyreg w 0x1f 0xd08
phyreg w 0x11 0x9
phyreg w 0x15 0x11
phyreg w 0x1f 0x0
phyreg w 0x0 0x9200
Also I have tested this on a X96 Max board without any .dts changes
to confirm that other boards with the same IP block still work fine
with these changes.
Changes since v3 at [3].
- added Florian's Reviewed-by to patch 1 (thank you!)
- rebased on top of net-next
Changes since v2 at [2]:
- use the generic property name "rx-internal-delay-ps" as suggested by
Rob (thanks!). This affects patches #1 and #3. The biggest change is
is in patch #1 which is why I didn't add Florian's and Andrew's
Reviewed-by
- added Andrew's and Florian's Reviewed-by to patches 2, 3, 4, 5 (many
thanks to both!). I decided to do this despite renaming the property
to the generic name "rx-internal-delay-ps" as it only affects the
patch description and one line of code
- updated patch description of patch #3 to explain why there's not a
lot of validation when parsing the old device-tree property (in
nanosecond precision)
- dropped RFC status
Changes since v1 at [1]:
- updated patch 1 by making it more clear when the RX delay is applied.
Thanks to Andrew for the suggestion!
- added a fix to enabling the timing-adjustment clock only when really
needed. Found by Andrew - thanks!
- added testing not about X96 Max
- v1 did not go to the netdev mailing list, v2 fixes this
net: stmmac: dwmac-meson8b: add support for the RGMII RX delay on G12A
Amlogic Meson G12A (and newer: G12B, SM1) SoCs have a more advanced RX
delay logic. Instead of fine-tuning the delay in the nanoseconds range
it now allows tuning in 200 picosecond steps. This support comes with
new bits in the PRG_ETH1[19:16] register.
Add support for validating the RGMII RX delay as well as configuring the
register accordingly on these platforms.
Reviewed-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: stmmac: dwmac-meson8b: move RGMII delays into a separate function
Newer SoCs starting with the Amlogic Meson G12A have more a precise
RGMII RX delay configuration register. This means more complexity in the
code. Extract the existing RGMII delay configuration code into a
separate function to make it easier to read/understand even when adding
more logic in the future.
Reviewed-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: stmmac: dwmac-meson8b: use picoseconds for the RGMII RX delay
Amlogic Meson G12A, G12B and SM1 SoCs have a more advanced RGMII RX
delay register which allows picoseconds precision. Parse the new
"rx-internal-delay-ps" property or fall back to the value from the old
"amlogic,rx-delay-ns" property.
No upstream DTB uses the old "amlogic,rx-delay-ns" property (yet).
Only include minimalistic logic to fall back to the old property,
without any special validation (for example if the old and new
property are given at the same time).
Reviewed-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: stmmac: dwmac-meson8b: fix enabling the timing-adjustment clock
The timing-adjustment clock only has to be enabled when a) there is a
2ns RX delay configured using device-tree and b) the phy-mode indicates
that the RX delay should be enabled.
Only enable the RX delay if both are true, instead of (by accident) also
enabling it when there's the 2ns RX delay configured but the phy-mode
incicates that the RX delay is not used.
Fixes: d743c50dfd8e45 ("net: stmmac: dwmac-meson8b: add support for the RX delay configuration") Reported-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
dt-bindings: net: dwmac-meson: use picoseconds for the RGMII RX delay
Amlogic Meson G12A, G12B and SM1 SoCs have a more advanced RGMII RX
delay register which allows picoseconds precision. Deprecate the old
"amlogic,rx-delay-ns" in favour of the generic "rx-internal-delay-ps"
property.
For older SoCs the only known supported values were 0ns and 2ns. The new
SoCs have support for RGMII RX delays between 0ps and 3000ps in 200ps
steps.
Don't carry over the description for the "rx-internal-delay-ps" property
and inherit that from ethernet-controller.yaml instead.
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
====================
Reduce coupling between DSA and Broadcom SYSTEMPORT driver
Upon a quick inspection, it seems that there is some code in the generic
DSA layer that is somehow specific to the Broadcom SYSTEMPORT driver.
The challenge there is that the hardware integration is very tight between
the switch and the DSA master interface. However this does not mean that
the drivers must also be as integrated as the hardware is. We can avoid
creating a DSA notifier just for the Broadcom SYSTEMPORT, and we can
move some Broadcom-specific queue mapping helpers outside of the common
include/net/dsa.h.
====================
Vladimir Oltean [Thu, 7 Jan 2021 01:24:03 +0000 (03:24 +0200)]
net: dsa: remove the DSA specific notifiers
This effectively reverts commit dfa1e5d77c79 ("net: dsa: Add support for
DSA specific notifiers"). The reason is that since commit 6a3226035fc2
("net: dsa: link interfaces with the DSA master to get rid of lockdep
warnings"), it appears that there is a generic way to achieve the same
purpose. The only user thus far, the Broadcom SYSTEMPORT driver, was
converted to use the generic notifiers.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Vladimir Oltean [Thu, 7 Jan 2021 01:24:02 +0000 (03:24 +0200)]
net: systemport: use standard netdevice notifier to detect DSA presence
The SYSTEMPORT driver maps each port of the embedded Broadcom DSA switch
port to a certain queue of the master Ethernet controller. For that it
currently uses a dedicated notifier infrastructure which was added in
commit dfa1e5d77c79 ("net: dsa: Add support for DSA specific notifiers").
However, since commit 6a3226035fc2 ("net: dsa: link interfaces with the
DSA master to get rid of lockdep warnings"), DSA is actually an upper of
the Broadcom SYSTEMPORT as far as the netdevice adjacency lists are
concerned. So naturally, the plain NETDEV_CHANGEUPPER net device notifiers
are emitted. It looks like there is enough API exposed by DSA to the
outside world already to make the call_dsa_notifiers API redundant. So
let's convert its only user to plain netdev notifiers.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Tested-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Vladimir Oltean [Thu, 7 Jan 2021 01:24:01 +0000 (03:24 +0200)]
net: dsa: export dsa_slave_dev_check
Using the NETDEV_CHANGEUPPER notifications, drivers can be aware when
they are enslaved to e.g. a bridge by calling netif_is_bridge_master().
Export this helper from DSA to get the equivalent functionality of
determining whether the upper interface of a CHANGEUPPER notifier is a
DSA switch interface or not.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Vladimir Oltean [Thu, 7 Jan 2021 01:24:00 +0000 (03:24 +0200)]
net: dsa: move the Broadcom tag information in a separate header file
It is a bit strange to see something as specific as Broadcom SYSTEMPORT
bits in the main DSA include file. Move these away into a separate
header, and have the tagger and the SYSTEMPORT driver include them.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
====================
Offload software learnt bridge addresses to DSA
This series tries to make DSA behave a bit more sanely when bridged with
"foreign" (non-DSA) interfaces and source address learning is not
supported on the hardware CPU port (which would make things work more
seamlessly without software intervention). When a station A connected to
a DSA switch port needs to talk to another station B connected to a
non-DSA port through the Linux bridge, DSA must explicitly add a route
for station B towards its CPU port.
Initial RFC was posted here:
https://patchwork.ozlabs.org/project/netdev/cover/20201108131953.2462644-1-olteanv@gmail.com/
v2 was posted here:
https://patchwork.kernel.org/project/netdevbpf/cover/20201213024018.772586-1-vladimir.oltean@nxp.com/
v3 was posted here:
https://patchwork.kernel.org/project/netdevbpf/cover/20201213140710.1198050-1-vladimir.oltean@nxp.com/
This is a resend of the previous v3 with some added Reviewed-by tags.
====================
Vladimir Oltean [Wed, 6 Jan 2021 09:51:36 +0000 (11:51 +0200)]
net: dsa: ocelot: request DSA to fix up lack of address learning on CPU port
Given the following setup:
ip link add br0 type bridge
ip link set eno0 master br0
ip link set swp0 master br0
ip link set swp1 master br0
ip link set swp2 master br0
ip link set swp3 master br0
Currently, packets received on a DSA slave interface (such as swp0)
which should be routed by the software bridge towards a non-switch port
(such as eno0) are also flooded towards the other switch ports (swp1,
swp2, swp3) because the destination is unknown to the hardware switch.
This patch addresses the issue by monitoring the addresses learnt by the
software bridge on eno0, and adding/deleting them as static FDB entries
on the CPU port accordingly.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Vladimir Oltean [Wed, 6 Jan 2021 09:51:35 +0000 (11:51 +0200)]
net: dsa: listen for SWITCHDEV_{FDB,DEL}_ADD_TO_DEVICE on foreign bridge neighbors
Some DSA switches (and not only) cannot learn source MAC addresses from
packets injected from the CPU. They only perform hardware address
learning from inbound traffic.
This can be problematic when we have a bridge spanning some DSA switch
ports and some non-DSA ports (which we'll call "foreign interfaces" from
DSA's perspective).
There are 2 classes of problems created by the lack of learning on
CPU-injected traffic:
- excessive flooding, due to the fact that DSA treats those addresses as
unknown
- the risk of stale routes, which can lead to temporary packet loss
To illustrate the second class, consider the following situation, which
is common in production equipment (wireless access points, where there
is a WLAN interface and an Ethernet switch, and these form a single
bridging domain).
- br0 of AP 1 will know that Clients A and B are reachable via wlan0
- the hardware fdb of a DSA switch driver today is not kept in sync with
the software entries on other bridge ports, so it will not know that
clients A and B are reachable via the CPU port UNLESS the hardware
switch itself performs SA learning from traffic injected from the CPU.
Nonetheless, a substantial number of switches don't.
- the hardware fdb of the DSA switch on AP 2 may autonomously learn that
Client A and B are reachable through swp0. Therefore, the software br0
of AP 2 also may or may not learn this. In the example we're
illustrating, some Ethernet traffic has been going on, and br0 from AP
2 has indeed learnt that it can reach Client B through swp0.
One of the wireless clients, say Client B, disconnects from AP 1 and
roams to AP 2. The topology now looks like this:
- br0 of AP 1 still knows that Client A is reachable via wlan0 (no change)
- br0 of AP 1 will (possibly) know that Client B has left wlan0. There
are cases where it might never find out though. Either way, DSA today
does not process that notification in any way.
- the hardware FDB of the DSA switch on AP 1 may learn autonomously that
Client B can be reached via swp0, if it receives any packet with
Client 1's source MAC address over Ethernet.
- the hardware FDB of the DSA switch on AP 2 still thinks that Client B
can be reached via swp0. It does not know that it has roamed to wlan0,
because it doesn't perform SA learning from the CPU port.
Now Client A contacts Client B.
AP 1 routes the packet fine towards swp0 and delivers it on the Ethernet
segment.
AP 2 sees a frame on swp0 and its fdb says that the destination is swp0.
Hairpinning is disabled => drop.
This problem comes from the fact that these switches have a 'blind spot'
for addresses coming from software bridging. The generic solution is not
to assume that hardware learning can be enabled somehow, but to listen
to more bridge learning events. It turns out that the bridge driver does
learn in software from all inbound frames, in __br_handle_local_finish.
A proper SWITCHDEV_FDB_ADD_TO_DEVICE notification is emitted for the
addresses serviced by the bridge on 'foreign' interfaces. The software
bridge also does the right thing on migration, by notifying that the old
entry is deleted, so that does not need to be special-cased in DSA. When
it is deleted, we just need to delete our static FDB entry towards the
CPU too, and wait.
The problem is that DSA currently only cares about SWITCHDEV_FDB_ADD_TO_DEVICE
events received on its own interfaces, such as static FDB entries.
Luckily we can change that, and DSA can listen to all switchdev FDB
add/del events in the system and figure out if those events were emitted
by a bridge that spans at least one of DSA's own ports. In case that is
true, DSA will also offload that address towards its own CPU port, in
the eventuality that there might be bridge clients attached to the DSA
switch who want to talk to the station connected to the foreign
interface.
In terms of implementation, we need to keep the fdb_info->added_by_user
check for the case where the switchdev event was targeted directly at a
DSA switch port. But we don't need to look at that flag for snooped
events. So the check is currently too late, we need to move it earlier.
This also simplifies the code a bit, since we avoid uselessly allocating
and freeing switchdev_work.
We could probably do some improvements in the future. For example,
multi-bridge support is rudimentary at the moment. If there are two
bridges spanning a DSA switch's ports, and both of them need to service
the same MAC address, then what will happen is that the migration of one
of those stations will trigger the deletion of the FDB entry from the
CPU port while it is still used by other bridge. That could be improved
with reference counting but is left for another time.
This behavior needs to be enabled at driver level by setting
ds->assisted_learning_on_cpu_port = true. This is because we don't want
to inflict a potential performance penalty (accesses through
MDIO/I2C/SPI are expensive) to hardware that really doesn't need it
because address learning on the CPU port works there.
Reported-by: DENG Qingfang <dqfext@gmail.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Vladimir Oltean [Wed, 6 Jan 2021 09:51:34 +0000 (11:51 +0200)]
net: dsa: exit early in dsa_slave_switchdev_event if we can't program the FDB
Right now, the following would happen for a switch driver that does not
implement .port_fdb_add or .port_fdb_del.
dsa_slave_switchdev_event returns NOTIFY_OK and schedules:
-> dsa_slave_switchdev_event_work
-> dsa_port_fdb_add
-> dsa_port_notify(DSA_NOTIFIER_FDB_ADD)
-> dsa_switch_fdb_add
-> if (!ds->ops->port_fdb_add) return -EOPNOTSUPP;
-> an error is printed with dev_dbg, and
dsa_fdb_offload_notify(switchdev_work) is not called.
We can avoid scheduling the worker for nothing and say NOTIFY_DONE.
Because we don't call dsa_fdb_offload_notify, the static FDB entry will
remain just in the software bridge.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Vladimir Oltean [Wed, 6 Jan 2021 09:51:33 +0000 (11:51 +0200)]
net: dsa: move switchdev event implementation under the same switch/case statement
We'll need to start listening to SWITCHDEV_FDB_{ADD,DEL}_TO_DEVICE
events even for interfaces where dsa_slave_dev_check returns false, so
we need that check inside the switch-case statement for SWITCHDEV_FDB_*.
This movement also avoids a useless allocation / free of switchdev_work
on the untreated "default event" case.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Vladimir Oltean [Wed, 6 Jan 2021 09:51:32 +0000 (11:51 +0200)]
net: dsa: don't use switchdev_notifier_fdb_info in dsa_switchdev_event_work
Currently DSA doesn't add FDB entries on the CPU port, because it only
does so through switchdev, which is associated with a net_device, and
there are none of those for the CPU port.
But actually FDB addresses on the CPU port have some use cases of their
own, if the switchdev operations are initiated from within the DSA
layer. There is just one problem with the existing code: it passes a
structure in dsa_switchdev_event_work which was retrieved directly from
switchdev, so it contains a net_device. We need to generalize the
contents to something that covers the CPU port as well: the "ds, port"
tuple is fine for that.
Note that the new procedure for notifying the successful FDB offload is
inspired from the rocker model.
Also, nothing was being done if added_by_user was false. Let's check for
that a lot earlier, and don't actually bother to schedule the worker
for nothing.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Vladimir Oltean [Wed, 6 Jan 2021 09:51:31 +0000 (11:51 +0200)]
net: dsa: be louder when a non-legacy FDB operation fails
The dev_close() call was added in commit 9a65c3fb3351 ("net: dsa: Add
support for learning FDB through notification") "to indicate inconsistent
situation" when we could not delete an FDB entry from the port.
bridge fdb del d8:58:d7:00:ca:6d dev swp0 self master
It is a bit drastic and at the same time not helpful if the above fails
to only print with netdev_dbg log level, but on the other hand to bring
the interface down.
So increase the verbosity of the error message, and drop dev_close().
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Vladimir Oltean [Wed, 6 Jan 2021 09:51:30 +0000 (11:51 +0200)]
net: bridge: notify switchdev of disappearance of old FDB entry upon migration
Currently the bridge emits atomic switchdev notifications for
dynamically learnt FDB entries. Monitoring these notifications works
wonders for switchdev drivers that want to keep their hardware FDB in
sync with the bridge's FDB.
For example station A wants to talk to station B in the diagram below,
and we are concerned with the behavior of the bridge on the DUT device:
Interfaces swp0, swp1, swp2 are handled by a switchdev driver that has
the following property: frames injected from its control interface bypass
the internal address analyzer logic, and therefore, this hardware does
not learn from the source address of packets transmitted by the network
stack through it. So, since bridging between eth0 (where Station B is
attached) and swp0 (where Station A is attached) is done in software,
the switchdev hardware will never learn the source address of Station B.
So the traffic towards that destination will be treated as unknown, i.e.
flooded.
This is where the bridge notifications come in handy. When br0 on the
DUT sees frames with Station B's MAC address on eth0, the switchdev
driver gets these notifications and can install a rule to send frames
towards Station B's address that are incoming from swp0, swp1, swp2,
only towards the control interface. This is all switchdev driver private
business, which the notification makes possible.
All is fine until someone unplugs Station B's cable and moves it to the
other switch:
Luckily for the use cases we care about, Station B is noisy enough that
the DUT hears it (on swp1 this time). swp1 receives the frames and
delivers them to the bridge, who enters the unlikely path in br_fdb_update
of updating an existing entry. It moves the entry in the software bridge
to swp1 and emits an addition notification towards that.
As far as the switchdev driver is concerned, all that it needs to ensure
is that traffic between Station A and Station B is not forever broken.
If it does nothing, then the stale rule to send frames for Station B
towards the control interface remains in place. But Station B is no
longer reachable via the control interface, but via a port that can
offload the bridge port learning attribute. It's just that the port is
prevented from learning this address, since the rule overrides FDB
updates. So the rule needs to go. The question is via what mechanism.
It sure would be possible for this switchdev driver to keep track of all
addresses which are sent to the control interface, and then also listen
for bridge notifier events on its own ports, searching for the ones that
have a MAC address which was previously sent to the control interface.
But this is cumbersome and inefficient. Instead, with one small change,
the bridge could notify of the address deletion from the old port, in a
symmetrical manner with how it did for the insertion. Then the switchdev
driver would not be required to monitor learn/forget events for its own
ports. It could just delete the rule towards the control interface upon
bridge entry migration. This would make hardware address learning be
possible again. Then it would take a few more packets until the hardware
and software FDB would be in sync again.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We've added 4 non-merge commits during the last 10 day(s) which contain
a total of 4 files changed, 14 insertions(+), 7 deletions(-).
The main changes are:
1) Fix task_iter bug caused by the merge conflict resolution, from Yonghong.
2) Fix resolve_btfids for multiple type hierarchies, from Jiri.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
bpftool: Fix compilation failure for net.o with older glibc
tools/resolve_btfids: Warn when having multiple IDs for single type
bpf: Fix a task_iter bug caused by a merge conflict resolution
selftests/bpf: Fix a compile error for BPF_F_BPRM_SECUREEXEC
====================
According to Realtek the ERI register 0x1a8 quirk is needed to work
around a hw issue with the PHY on RTL8168g. The register needs to be
changed before powering down the PHY. Currently we don't meet this
requirement, however I'm not aware of any problems caused by this.
Therefore I see the change as an improvement.
The PHY driver has no means to access the chip ERI registers,
therefore we have to intercept MDIO writes to the BMCR register.
If the BMCR_PDOWN bit is going to be set, then let's apply the
quirk before actually powering down the PHY.
====================
Heiner Kallweit [Wed, 6 Jan 2021 10:49:50 +0000 (11:49 +0100)]
r8169: improve RTL8168g PHY suspend quirk
According to Realtek the ERI register 0x1a8 quirk is needed to work
around a hw issue with the PHY on RTL8168g. The register needs to be
changed before powering down the PHY. Currently we don't meet this
requirement, however I'm not aware of any problems caused by this.
Therefore I see the change as an improvement.
The PHY driver has no means to access the chip ERI registers,
therefore we have to intercept MDIO writes to BMCR register.
If the BMCR_PDOWN bit is going to be set, then let's apply the
quirk before actually powering down the PHY.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>