Currently, parse-torture.sh looks at the fifth field of torture-test
console output for the version number. This works fine for rcutorture,
but not for scftorture, which lacks the pointer field. This commit
therefore adjusts matching lines so that the parse-console.sh awk script
always sees the version number as the first field in the lines passed
to it.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Currently, the test takes about 626 seconds to complete because of an
inefficient use of the device's TCAM. Reduce the runtime to 202 seconds
by inserting all the flower filters with the same preference and mask,
but with a different key.
In particular, this reduces the deletion of the qdisc (which triggers
the deletion of all the filters) from 66 seconds to 0.2 seconds. This
prevents various netlink requests from user space applications (e.g.,
systemd-networkd) from timing-out because RTNL is not held for too long
anymore.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, mausezahn delay parameter in mirror_test() is specified with
'ms' units.
mausezahn versions before 0.6.5 interpret 'ms' as seconds and therefore
the tests that use mirror_test() take a very long time to complete.
Resolve this by specifying 'msec' units.
Signed-off-by: Danielle Ratson <danieller@mellanox.com>
Reviewed-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The current combination of rate and burst size does not adhere to
Spectrum-{2,3} limitation which states that the minimum burst size
should be 40% of the rate.
Increase the burst size in order to honor above mentioned limitation and
avoid intermittent failures of this test case on Spectrum-{2,3}.
Remove the first sub-test case as the variation in number of received
packets is simply too large to reliably test it.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The current combination of rate and burst size does not adhere to
Spectrum-{2,3} limitation which states that the minimum burst size
should be 40% of the rate.
Increase the burst size in order to honor above mentioned limitation and
avoid intermittent failures of this test case on Spectrum-{2,3}.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
On Spectrum-{2,3} the required accuracy is +/-10%.
Align the test to this requirement so that it can reliably pass on these
platforms.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds tests for the new bpf tcp header option feature.
test_tcp_hdr_options.c:
- It tests header option writing and parsing in 3WHS: regular
connection establishment, fastopen, and syncookie.
- In syncookie, the passive side's bpf prog is asking the active side
to resend its bpf header option by specifying a RESEND bit in the
outgoing SYNACK. handle_active_estab() and write_nodata_opt() has
some details.
- handle_passive_estab() has comments on fastopen.
- It also has test for header writing and parsing in FIN packet.
- Most of the tests is writing an experimental option 254 with magic 0xeB9F.
- The no_exprm_estab() also tests writing a regular TCP option
without any magic.
test_misc_tcp_options.c:
- It is an one directional test. Active side writes option and
passive side parses option. The focus is to exercise
the new helpers and API.
- Testing the new helper: bpf_load_hdr_opt() and bpf_store_hdr_opt().
- Testing the bpf_getsockopt(TCP_BPF_SYN).
- Negative tests for the above helpers.
- Testing the sock_ops->skb_data.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200820190117.2886749-1-kafai@fb.com
Pull networking fixes from David Miller:
"Nothing earth shattering here, lots of small fixes (f.e. missing RCU
protection, bad ref counting, missing memset(), etc.) all over the
place:
1) Use get_file_rcu() in task_file iterator, from Yonghong Song.
2) There are two ways to set remote source MAC addresses in macvlan
driver, but only one of which validates things properly. Fix this.
From Alvin Šipraga.
3) Missing of_node_put() in gianfar probing, from Sumera
Priyadarsini.
4) Preserve device wanted feature bits across multiple netlink
ethtool requests, from Maxim Mikityanskiy.
5) Fix rcu_sched stall in task and task_file bpf iterators, from
Yonghong Song.
6) Avoid reset after device destroy in ena driver, from Shay
Agroskin.
7) Missing memset() in netlink policy export reallocation path, from
Johannes Berg.
8) Fix info leak in __smc_diag_dump(), from Peilin Ye.
9) Decapsulate ECN properly for ipv6 in ipv4 tunnels, from Mark
Tomlinson.
10) Fix number of data stream negotiation in SCTP, from David Laight.
11) Fix double free in connection tracker action module, from Alaa
Hleihel.
12) Don't allow empty NHA_GROUP attributes, from Nikolay Aleksandrov"
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (46 commits)
net: nexthop: don't allow empty NHA_GROUP
bpf: Fix two typos in uapi/linux/bpf.h
net: dsa: b53: check for timeout
tipc: call rcu_read_lock() in tipc_aead_encrypt_done()
net/sched: act_ct: Fix skb double-free in tcf_ct_handle_fragments() error flow
net: sctp: Fix negotiation of the number of data streams.
dt-bindings: net: renesas, ether: Improve schema validation
gre6: Fix reception with IP6_TNL_F_RCV_DSCP_COPY
hv_netvsc: Fix the queue_mapping in netvsc_vf_xmit()
hv_netvsc: Remove "unlikely" from netvsc_select_queue
bpf: selftests: global_funcs: Check err_str before strstr
bpf: xdp: Fix XDP mode when no mode flags specified
selftests/bpf: Remove test_align leftovers
tools/resolve_btfids: Fix sections with wrong alignment
net/smc: Prevent kernel-infoleak in __smc_diag_dump()
sfc: fix build warnings on 32-bit
net: phy: mscc: Fix a couple of spelling mistakes "spcified" -> "specified"
libbpf: Fix map index used in error message
net: gemini: Fix missing free_netdev() in error path of gemini_ethernet_port_probe()
net: atlantic: Use readx_poll_timeout() for large timeout
...
Pull kvm fixes from Paolo Bonzini:
- PAE and PKU bugfixes for x86
- selftests fix for new binutils
- MMU notifier fix for arm64
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: arm64: Only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE is not set
KVM: Pass MMU notifier range flags to kvm_unmap_hva_range()
kvm: x86: Toggling CR4.PKE does not load PDPTEs in PAE mode
kvm: x86: Toggling CR4.SMAP does not load PDPTEs in PAE mode
KVM: x86: fix access code passed to gva_to_gpa
selftests: kvm: Use a shorter encoding to clear RAX
Add a test which copies a socket from a sockmap into another sockmap
or sockhash. This excercises bpf_map_update_elem support from BPF
context. Compare the socket cookies from source and destination to
ensure that the copy succeeded.
Also check that the verifier rejects map_update from unsafe contexts.
Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200821102948.21918-7-lmb@cloudflare.com
Add a set of APIs to perf_buffer manage to allow applications to integrate
perf buffer polling into existing epoll-based infrastructure. One example is
applications using libevent already and wanting to plug perf_buffer polling,
instead of relying on perf_buffer__poll() and waste an extra thread to do it.
But perf_buffer is still extremely useful to set up and consume perf buffer
rings even for such use cases.
So to accomodate such new use cases, add three new APIs:
- perf_buffer__buffer_cnt() returns number of per-CPU buffers maintained by
given instance of perf_buffer manager;
- perf_buffer__buffer_fd() returns FD of perf_event corresponding to
a specified per-CPU buffer; this FD is then polled independently;
- perf_buffer__consume_buffer() consumes data from single per-CPU buffer,
identified by its slot index.
To support a simpler, but less efficient, way to integrate perf_buffer into
external polling logic, also expose underlying epoll FD through
perf_buffer__epoll_fd() API. It will need to be followed by
perf_buffer__poll(), wasting extra syscall, or perf_buffer__consume(), wasting
CPU to iterate buffers with no data. But could be simpler and more convenient
for some cases.
These APIs allow for great flexiblity, but do not sacrifice general usability
of perf_buffer.
Also exercise and check new APIs in perf_buffer selftest.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/20200821165927.849538-1-andriin@fb.com
Alexei Starovoitov says:
====================
pull-request: bpf 2020-08-21
The following pull-request contains BPF updates for your *net* tree.
We've added 11 non-merge commits during the last 5 day(s) which contain
a total of 12 files changed, 78 insertions(+), 24 deletions(-).
The main changes are:
1) three fixes in BPF task iterator logic, from Yonghong.
2) fix for compressed dwarf sections in vmlinux, from Jiri.
3) fix xdp attach regression, from Andrii.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
One down side of using TCP rx zerocopy is one extra TLB miss
per page after the mapping operation.
While if the application is using hugepages, the non zerocopy
recvmsg() will not have to pay these TLB costs.
This patch allows server side to use huge pages for
the non zero copy case, to allow fair comparisons when
both solutions use optimal conditions.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Arjun Roy <arjunroy@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When TCP_ZEROCOPY_RECEIVE operation has been added,
I made the mistake of automatically un-mapping prior
content before mapping new pages.
This has the unfortunate effect of adding potentially long
MMU operations (like TLB flushes) while socket lock is held.
Using madvise(MADV_DONTNEED) right after pages has been used
has two benefits :
1) This releases pages sooner, allowing pages to be recycled
if they were part of a page pool in a NIC driver.
2) No more long unmap operations while preventing immediate
processing of incoming packets.
The cost of the added system call is small enough.
Arjun will submit a kernel patch allowing to opt out from
the unmap attempt in tcp_zerocopy_receive()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Arjun Roy <arjunroy@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The following 4 tests in timers can take longer than the default 45
seconds that added in commit 852c8cbf34 ("selftests/kselftest/runner.sh:
Add 45 second timeout per test") to run:
* nsleep-lat - 2m7.350s
* set-timer-lat - 2m0.66s
* inconsistency-check - 1m45.074s
* raw_skew - 2m0.013s
Thus they will be marked as failed with the current 45s setting:
not ok 3 selftests: timers: nsleep-lat # TIMEOUT
not ok 4 selftests: timers: set-timer-lat # TIMEOUT
not ok 6 selftests: timers: inconsistency-check # TIMEOUT
not ok 7 selftests: timers: raw_skew # TIMEOUT
Disable the timeout setting for timers can make these tests finish
properly:
ok 3 selftests: timers: nsleep-lat
ok 4 selftests: timers: set-timer-lat
ok 6 selftests: timers: inconsistency-check
ok 7 selftests: timers: raw_skew
https://bugs.launchpad.net/bugs/1864626
Fixes: 852c8cbf34 ("selftests/kselftest/runner.sh: Add 45 second timeout per test")
Signed-off-by: Po-Hsu Lin <po-hsu.lin@canonical.com>
Acked-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
The error path in libbpf.c:load_program() has calls to pr_warn()
which ends up for global_funcs tests to
test_global_funcs.c:libbpf_debug_print().
For the tests with no struct test_def::err_str initialized with a
string, it causes call of strstr() with NULL as the second argument
and it segfaults.
Fix it by calling strstr() only for non-NULL err_str.
Signed-off-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200820115843.39454-1-yauheni.kaliuta@redhat.com
Add tests for BTF type ID relocations. To allow testing this, enhance
core_relo.c test runner to allow dynamic initialization of test inputs.
If Clang doesn't have necessary support for new functionality, test is
skipped.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200819194519.3375898-4-andriin@fb.com
Add selftests for TYPE_EXISTS and TYPE_SIZE relocations, testing correctness
of relocations and handling of type compatiblity/incompatibility.
If __builtin_preserve_type_info() is not supported by compiler, skip tests.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200819194519.3375898-3-andriin@fb.com
Pull networking fixes from David Miller:
"Another batch of fixes:
1) Remove nft_compat counter flush optimization, it generates warnings
from the refcount infrastructure. From Florian Westphal.
2) Fix BPF to search for build id more robustly, from Jiri Olsa.
3) Handle bogus getopt lengths in ebtables, from Florian Westphal.
4) Infoleak and other fixes to j1939 CAN driver, from Eric Dumazet and
Oleksij Rempel.
5) Reset iter properly on mptcp sendmsg() error, from Florian
Westphal.
6) Show a saner speed in bonding broadcast mode, from Jarod Wilson.
7) Various kerneldoc fixes in bonding and elsewhere, from Lee Jones.
8) Fix double unregister in bonding during namespace tear down, from
Cong Wang.
9) Disable RP filter during icmp_redirect selftest, from David Ahern"
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (75 commits)
otx2_common: Use devm_kcalloc() in otx2_config_npa()
net: qrtr: fix usage of idr in port assignment to socket
selftests: disable rp_filter for icmp_redirect.sh
Revert "net: xdp: pull ethernet header off packet after computing skb->protocol"
phylink: <linux/phylink.h>: fix function prototype kernel-doc warning
mptcp: sendmsg: reset iter on error redux
net: devlink: Remove overzealous WARN_ON with snapshots
tipc: not enable tipc when ipv6 works as a module
tipc: fix uninit skb->data in tipc_nl_compat_dumpit()
net: Fix potential wrong skb->protocol in skb_vlan_untag()
net: xdp: pull ethernet header off packet after computing skb->protocol
ipvlan: fix device features
bonding: fix a potential double-unregister
can: j1939: add rxtimer for multipacket broadcast session
can: j1939: abort multipacket broadcast session when timeout occurs
can: j1939: cancel rxtimer on multipacket broadcast session complete
can: j1939: fix support for multipacket broadcast message
net: fddi: skfp: cfm: Remove seemingly unused variable 'ID_sccs'
net: fddi: skfp: cfm: Remove set but unused variable 'oldstate'
net: fddi: skfp: smt: Remove seemingly unused variable 'ID_sccs'
...
h1 is initially configured to reach h2 via r1 rather than the
more direct path through r2. If rp_filter is set and inherited
for r2, forwarding fails since the source address of h1 is
reachable from eth0 vs the packet coming to it via r1 and eth1.
Since rp_filter setting affects the test, explicitly reset it.
Signed-off-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
If debug_regs.c is built with newer binutils, the resulting binary is "optimized"
by the assembler:
asm volatile("ss_start: "
"xor %%rax,%%rax\n\t"
"cpuid\n\t"
"movl $0x1a0,%%ecx\n\t"
"rdmsr\n\t"
: : : "rax", "ecx");
is translated to :
000000000040194e <ss_start>:
40194e: 31 c0 xor %eax,%eax <----- rax->eax?
401950: 0f a2 cpuid
401952: b9 a0 01 00 00 mov $0x1a0,%ecx
401957: 0f 32 rdmsr
As you can see rax is replaced with eax in target binary code.
This causes a difference is the length of xor instruction (2 Byte vs 3 Byte),
and makes the hard-coded instruction length check fail:
/* Instruction lengths starting at ss_start */
int ss_size[4] = {
3, /* xor */ <-------- 2 or 3?
2, /* cpuid */
5, /* mov */
2, /* rdmsr */
};
Encode the shorter version directly and, while at it, fix the "clobbers"
of the asm.
Cc: stable@vger.kernel.org
Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
The following patchset contains Netfilter fixes for net:
1) Endianness issue in IPv4 option support in nft_exthdr,
from Stephen Suryaputra.
2) Removes the waitcount optimization in nft_compat,
from Florian Westphal.
3) Remove ipv6 -> nf_defrag_ipv6 module dependency, from
Florian Westphal.
4) Memleak in chain binding support, also from Florian.
5) Simplify nft_flowtable.sh selftest, from Fabian Frederick.
6) Optional MTU arguments for selftest nft_flowtable.sh,
also from Fabian.
7) Remove noise error report when killing process in
selftest nft_flowtable.sh, from Fabian Frederick.
8) Reject bogus getsockopt option length in ebtables,
from Florian Westphal.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull arch/sh updates from Rich Felker:
"Cleanup, SECCOMP_FILTER support, message printing fixes, and other
changes to arch/sh"
* tag 'sh-for-5.9' of git://git.libc.org/linux-sh: (34 commits)
sh: landisk: Add missing initialization of sh_io_port_base
sh: bring syscall_set_return_value in line with other architectures
sh: Add SECCOMP_FILTER
sh: Rearrange blocks in entry-common.S
sh: switch to copy_thread_tls()
sh: use the generic dma coherent remap allocator
sh: don't allow non-coherent DMA for NOMMU
dma-mapping: consolidate the NO_DMA definition in kernel/dma/Kconfig
sh: unexport register_trapped_io and match_trapped_io_handler
sh: don't include <asm/io_trapped.h> in <asm/io.h>
sh: move the ioremap implementation out of line
sh: move ioremap_fixed details out of <asm/io.h>
sh: remove __KERNEL__ ifdefs from non-UAPI headers
sh: sort the selects for SUPERH alphabetically
sh: remove -Werror from Makefiles
sh: Replace HTTP links with HTTPS ones
arch/sh/configs: remove obsolete CONFIG_SOC_CAMERA*
sh: stacktrace: Remove stacktrace_ops.stack()
sh: machvec: Modernize printing of kernel messages
sh: pci: Modernize printing of kernel messages
...
Daniel Borkmann says:
====================
pull-request: bpf 2020-08-15
The following pull-request contains BPF updates for your *net* tree.
We've added 23 non-merge commits during the last 4 day(s) which contain
a total of 32 files changed, 421 insertions(+), 141 deletions(-).
The main changes are:
1) Fix sock_ops ctx access splat due to register override, from John Fastabend.
2) Batch of various fixes to libbpf, bpftool, and selftests when testing build
in 32-bit mode, from Andrii Nakryiko.
3) Fix vmlinux.h generation on ARM by mapping GCC built-in types (__Poly*_t)
to equivalent ones clang can work with, from Jean-Philippe Brucker.
4) Fix build_id lookup in bpf_get_stackid() helper by walking all NOTE ELF
sections instead of just first, from Jiri Olsa.
5) Avoid use of __builtin_offsetof() in libbpf for CO-RE, from Yonghong Song.
6) Fix segfault in test_mmap due to inconsistent length params, from Jianlin Lv.
7) Don't override errno in libbpf when logging errors, from Toke Høiland-Jørgensen.
8) Fix v4_to_v6 sockaddr conversion in sk_lookup test, from Stanislav Fomichev.
9) Add link to bpf-helpers(7) man page to BPF doc, from Joe Stringer.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull networking fixes from David Miller:
"Some merge window fallout, some longer term fixes:
1) Handle headroom properly in lapbether and x25_asy drivers, from
Xie He.
2) Fetch MAC address from correct r8152 device node, from Thierry
Reding.
3) In the sw kTLS path we should allow MSG_CMSG_COMPAT in sendmsg,
from Rouven Czerwinski.
4) Correct fdputs in socket layer, from Miaohe Lin.
5) Revert troublesome sockptr_t optimization, from Christoph Hellwig.
6) Fix TCP TFO key reading on big endian, from Jason Baron.
7) Missing CAP_NET_RAW check in nfc, from Qingyu Li.
8) Fix inet fastreuse optimization with tproxy sockets, from Tim
Froidcoeur.
9) Fix 64-bit divide in new SFC driver, from Edward Cree.
10) Add a tracepoint for prandom_u32 so that we can more easily
perform usage analysis. From Eric Dumazet.
11) Fix rwlock imbalance in AF_PACKET, from John Ogness"
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (49 commits)
net: openvswitch: introduce common code for flushing flows
af_packet: TPACKET_V3: fix fill status rwlock imbalance
random32: add a tracepoint for prandom_u32()
Revert "ipv4: tunnel: fix compilation on ARCH=um"
net: accept an empty mask in /sys/class/net/*/queues/rx-*/rps_cpus
net: ethernet: stmmac: Disable hardware multicast filter
net: stmmac: dwmac1000: provide multicast filter fallback
ipv4: tunnel: fix compilation on ARCH=um
vsock: fix potential null pointer dereference in vsock_poll()
sfc: fix ef100 design-param checking
net: initialize fastreuse on inet_inherit_port
net: refactor bind_bucket fastreuse into helper
net: phy: marvell10g: fix null pointer dereference
net: Fix potential memory leak in proto_register()
net: qcom/emac: add missed clk_disable_unprepare in error path of emac_clks_phase1_init
ionic_lif: Use devm_kcalloc() in ionic_qcq_alloc()
net/nfc/rawsock.c: add CAP_NET_RAW check.
hinic: fix strncpy output truncated compile warnings
drivers/net/wan/x25_asy: Added needed_headroom and a skb->len check
net/tls: Fix kmap usage
...
Despite bpftool generating data section memory layout that will work for
32-bit architectures on user-space side, BPF programs should be careful to not
use ambiguous types like `long`, which have different size in 32-bit and
64-bit environments. Fix that in test by using __u64 explicitly, which is
a recommended approach anyway.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200813204945.1020225-10-andriin@fb.com
Fix btf_dump test cases by hard-coding BPF's pointer size of 8 bytes for cases
where it's impossible to deterimne the pointer size (no long type in BTF). In
cases where it's known, validate libbpf correctly determines it as 8.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200813204945.1020225-6-andriin@fb.com
Add tests to directly accesse sock_ops sk field. Then use it to
ensure a bad pointer access will fault if something goes wrong.
We do three tests:
The first test ensures when we read sock_ops sk pointer into the
same register that we don't fault as described earlier. Here r9
is chosen as the temp register. The xlated code is,
36: (7b) *(u64 *)(r1 +32) = r9
37: (61) r9 = *(u32 *)(r1 +28)
38: (15) if r9 == 0x0 goto pc+3
39: (79) r9 = *(u64 *)(r1 +32)
40: (79) r1 = *(u64 *)(r1 +0)
41: (05) goto pc+1
42: (79) r9 = *(u64 *)(r1 +32)
The second test ensures the temp register selection does not collide
with in-use register r9. Shown here r8 is chosen because r9 is the
sock_ops pointer. The xlated code is as follows,
46: (7b) *(u64 *)(r9 +32) = r8
47: (61) r8 = *(u32 *)(r9 +28)
48: (15) if r8 == 0x0 goto pc+3
49: (79) r8 = *(u64 *)(r9 +32)
50: (79) r9 = *(u64 *)(r9 +0)
51: (05) goto pc+1
52: (79) r8 = *(u64 *)(r9 +32)
And finally, ensure we didn't break the base case where dst_reg does
not equal the source register,
56: (61) r2 = *(u32 *)(r1 +28)
57: (15) if r2 == 0x0 goto pc+1
58: (79) r2 = *(u64 *)(r1 +0)
Notice it takes us an extra four instructions when src reg is the
same as dst reg. One to save the reg, two to restore depending on
the branch taken and a goto to jump over the second restore.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/159718355325.4728.4163036953345999636.stgit@john-Precision-5820-Tower
Loads in sock_ops case when using high registers requires extra logic to
ensure the correct temporary value is used. We need to ensure the temp
register does not use either the src_reg or dst_reg. Lets add an asm
test to force the logic is triggered.
The xlated code is here,
30: (7b) *(u64 *)(r9 +32) = r7
31: (61) r7 = *(u32 *)(r9 +28)
32: (15) if r7 == 0x0 goto pc+2
33: (79) r7 = *(u64 *)(r9 +0)
34: (63) *(u32 *)(r7 +916) = r8
35: (79) r7 = *(u64 *)(r9 +32)
Notice r9 and r8 are not used for temp registers and r7 is chosen.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/159718353345.4728.8805043614257933227.stgit@john-Precision-5820-Tower
To verify fix ("bpf: sock_ops ctx access may stomp registers in corner case")
we want to force compiler to generate the following code when accessing a
field with BPF_TCP_SOCK_GET_COMMON,
r1 = *(u32 *)(r1 + 96) // r1 is skops ptr
Rather than depend on clang to do this we add the test with inline asm to
the tcpbpf test. This saves us from having to create another runner and
ensures that if we break this again test_tcpbpf will crash.
With above code we get the xlated code,
11: (7b) *(u64 *)(r1 +32) = r9
12: (61) r9 = *(u32 *)(r1 +28)
13: (15) if r9 == 0x0 goto pc+4
14: (79) r9 = *(u64 *)(r1 +32)
15: (79) r1 = *(u64 *)(r1 +0)
16: (61) r1 = *(u32 *)(r1 +2348)
17: (05) goto pc+1
18: (79) r9 = *(u64 *)(r1 +32)
We also add the normal case where src_reg != dst_reg so we can compare
code generation easily from llvm-objdump and ensure that case continues
to work correctly. The normal code is xlated to,
20: (b7) r1 = 0
21: (61) r1 = *(u32 *)(r3 +28)
22: (15) if r1 == 0x0 goto pc+2
23: (79) r1 = *(u64 *)(r3 +0)
24: (61) r1 = *(u32 *)(r1 +2348)
Where the temp variable is not used.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/159718351457.4728.3295119261717842496.stgit@john-Precision-5820-Tower
