Commit 66be4e66a7 ("rcu: locking and unlocking need to always be at
least barriers") added compiler barriers back into rcu_read_lock() and
rcu_read_unlock(). Furthermore, srcu_read_lock() and
srcu_read_unlock() have always contained compiler barriers.
The Linux Kernel Memory Model ought to know about these barriers.
This patch adds them into the memory model.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Andrea Parri <andrea.parri@amarulasolutions.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Pull still more SPDX updates from Greg KH:
"Another round of SPDX updates for 5.2-rc6
Here is what I am guessing is going to be the last "big" SPDX update
for 5.2. It contains all of the remaining GPLv2 and GPLv2+ updates
that were "easy" to determine by pattern matching. The ones after this
are going to be a bit more difficult and the people on the spdx list
will be discussing them on a case-by-case basis now.
Another 5000+ files are fixed up, so our overall totals are:
Files checked: 64545
Files with SPDX: 45529
Compared to the 5.1 kernel which was:
Files checked: 63848
Files with SPDX: 22576
This is a huge improvement.
Also, we deleted another 20000 lines of boilerplate license crud,
always nice to see in a diffstat"
* tag 'spdx-5.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx: (65 commits)
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 507
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 506
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 505
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 504
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 503
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 502
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 501
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 498
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 497
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 496
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 495
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 491
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 490
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 489
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 488
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 487
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 486
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 485
...
Pull kvm fixes from Paolo Bonzini:
"Fixes for ARM and x86, plus selftest patches and nicer structs for
nested state save/restore"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: nVMX: reorganize initial steps of vmx_set_nested_state
KVM: arm/arm64: Fix emulated ptimer irq injection
tests: kvm: Check for a kernel warning
kvm: tests: Sort tests in the Makefile alphabetically
KVM: x86/mmu: Allocate PAE root array when using SVM's 32-bit NPT
KVM: x86: Modify struct kvm_nested_state to have explicit fields for data
KVM: fix typo in documentation
KVM: nVMX: use correct clean fields when copying from eVMCS
KVM: arm/arm64: vgic: Fix kvm_device leak in vgic_its_destroy
KVM: arm64: Filter out invalid core register IDs in KVM_GET_REG_LIST
KVM: arm64: Implement vq_present() as a macro
Commit 332d079735 ("KVM: nVMX: KVM_SET_NESTED_STATE - Tear down old EVMCS
state before setting new state", 2019-05-02) broke evmcs_test because the
eVMCS setup must be performed even if there is no VMXON region defined,
as long as the eVMCS bit is set in the assist page.
While the simplest possible fix would be to add a check on
kvm_state->flags & KVM_STATE_NESTED_EVMCS in the initial "if" that
covers kvm_state->hdr.vmx.vmxon_pa == -1ull, that is quite ugly.
Instead, this patch moves checks earlier in the function and
conditionalizes them on kvm_state->hdr.vmx.vmxon_pa, so that
vmx_set_nested_state always goes through vmx_leave_nested
and nested_enable_evmcs.
Fixes: 332d079735 ("KVM: nVMX: KVM_SET_NESTED_STATE - Tear down old EVMCS state before setting new state")
Cc: Aaron Lewis <aaronlewis@google.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Alexei Starovoitov says:
====================
pull-request: bpf-next 2019-06-19
The following pull-request contains BPF updates for your *net-next* tree.
The main changes are:
1) new SO_REUSEPORT_DETACH_BPF setsocktopt, from Martin.
2) BTF based map definition, from Andrii.
3) support bpf_map_lookup_elem for xskmap, from Jonathan.
4) bounded loops and scalar precision logic in the verifier, from Alexei.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Kselftest can be run against older kernels. Instead of failing hard
when a feature is unsupported, return the KSFT_SKIP exit code.
Specifically, do not fail hard on missing udp zerocopy.
The udp gso bench test runs multiple test cases from a single script.
Fail if any case fails, else return skip if any test is skipped.
Link: https://lore.kernel.org/lkml/20190618171516.GA17547@kroah.com/
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Based on 2 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 4122 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation this program is
distributed in the hope that it would be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 1 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Enrico Weigelt <info@metux.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081204.982710800@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details you should have received a copy of the gnu general
public license along with this program if not see http www gnu org
licenses
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 503 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Enrico Weigelt <info@metux.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When running with /sys/module/kvm_intel/parameters/unrestricted_guest=N,
test that a kernel warning does not occur informing us that
vcpu->mmio_needed=1. This can happen when KVM_RUN is called after a
triple fault.
This test was made to detect a bug that was reported by Syzkaller
(https://groups.google.com/forum/#!topic/syzkaller/lHfau8E3SOE) and
fixed with commit bbeac2830f ("KVM: X86: Fix residual mmio emulation
request to userspace").
Signed-off-by: Aaron Lewis <aaronlewis@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Peter Shier <pshier@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Improve the KVM_{GET,SET}_NESTED_STATE structs by detailing the format
of VMX nested state data in a struct.
In order to avoid changing the ioctl values of
KVM_{GET,SET}_NESTED_STATE, there is a need to preserve
sizeof(struct kvm_nested_state). This is done by defining the data
struct as "data.vmx[0]". It was the most elegant way I found to
preserve struct size while still keeping struct readable and easy to
maintain. It does have a misfortunate side-effect that now it has to be
accessed as "data.vmx[0]" rather than just "data.vmx".
Because we are already modifying these structs, I also modified the
following:
* Define the "format" field values as macros.
* Rename vmcs_pa to vmcs12_pa for better readability.
Signed-off-by: Liran Alon <liran.alon@oracle.com>
[Remove SVM stubs, add KVM_STATE_NESTED_VMX_VMCS12_SIZE. - Paolo]
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Extend tc_flower to test plain ingress device matching and also
tc_shblock to test ingress device matching on shared block.
Add new tc_flower_router.sh where ingress device matching on egress
(after routing) is done.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In some cases, compiler can allocate the same register for operand 'res'
and 'vecoutptr', resulting in segfault at 'stxvd2x 40,0,%[vecoutptr]'
because base register will contain 1, yielding a false-positive.
This is because output 'res' must be marked as an earlyclobber operand so
it may not overlap an input operand ('vecoutptr').
Signed-off-by: Gustavo Romero <gromero@linux.vnet.ibm.com>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add a bunch of loop tests. Most of them are created by replacing
'#pragma unroll' with '#pragma clang loop unroll(disable)'
Several tests are artificially large:
/* partial unroll. llvm will unroll loop ~150 times.
* C loop count -> 600.
* Asm loop count -> 4.
* 16k insns in loop body.
* Total of 5 such loops. Total program size ~82k insns.
*/
"./pyperf600.o",
/* no unroll at all.
* C loop count -> 600.
* ASM loop count -> 600.
* ~110 insns in loop body.
* Total of 5 such loops. Total program size ~1500 insns.
*/
"./pyperf600_nounroll.o",
/* partial unroll. 19k insn in a loop.
* Total program size 20.8k insn.
* ~350k processed_insns
*/
"./strobemeta.o",
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
fix tests that incorrectly assumed that the verifier
cannot track constants through stack.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Add const qualifiers to bpf_object/bpf_program/bpf_map arguments for
getter APIs. There is no need for them to not be const pointers.
Verified that
make -C tools/lib/bpf
make -C tools/testing/selftests/bpf
make -C tools/perf
all build without warnings.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
We were renanimg 'main' to 'main_zstd' but then using 'main_libzstd();'
in the main() for test-all.c, causing this:
$ cat /tmp/build/perf/feature/test-all.make.output
test-all.c: In function ‘main’:
test-all.c:236:2: error: implicit declaration of function ‘main_test_libzstd’; did you mean ‘main_test_zstd’? [-Werror=implicit-function-declaration]
main_test_libzstd();
^~~~~~~~~~~~~~~~~
main_test_zstd
cc1: all warnings being treated as errors
$
I.e. what was supposed to be the fast path feature test was _always_
failing, duh, fix it.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Fixes: 3b1c5d9659 ("tools build: Implement libzstd feature check, LIBZSTD_DIR and NO_LIBZSTD defines")
Link: https://lkml.kernel.org/n/tip-ma4abk0utroiw4mwpmvnjlru@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
In some distros slang.h may be in a /usr/include 'slang' subdir, so use
the if slang is not explicitely disabled (by using NO_SLANG=1) and its
feature test for the common case (having /usr/include/slang.h) failed,
use the results for the test that checks if it is in slang/slang.h.
Change the only file in perf that includes slang.h to use
HAVE_SLANG_INCLUDE_SUBDIR and forget about this for good.
On a rhel6 system now we have:
$ /tmp/build/perf/perf -vv | grep slang
libslang: [ on ] # HAVE_SLANG_SUPPORT
$ ldd /tmp/build/perf/perf | grep libslang
libslang.so.2 => /usr/lib64/libslang.so.2 (0x00007fa2d5a8d000)
$ grep slang /tmp/build/perf/FEATURE-DUMP
feature-libslang=0
feature-libslang-include-subdir=1
$ cat /etc/redhat-release
CentOS release 6.10 (Final)
$
While on fedora:29:
$ /tmp/build/perf/perf -vv | grep slang
libslang: [ on ] # HAVE_SLANG_SUPPORT
$ ldd /tmp/build/perf/perf | grep slang
libslang.so.2 => /lib64/libslang.so.2 (0x00007f8eb11a7000)
$ grep slang /tmp/build/perf/FEATURE-DUMP
feature-libslang=1
feature-libslang-include-subdir=1
$
$ cat /etc/fedora-release
Fedora release 29 (Twenty Nine)
$
The feature-libslang-include-subdir=1 line is because the 'gettid()'
test was added to test-all.c as the new glibc has an implementation for
that, so we soon should have it not failing, i.e. should be the common
case soon. Perhaps I should move it out till it becomes the norm...
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Fixes: 1955c8cf5e ("perf tools: Don't hardcode host include path for libslang")
Link: https://lkml.kernel.org/n/tip-bkgtpsu3uit821fuwsdhj9gd@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
A few odd old distros (rhel5, 6, yeah, lots of those out in use, in many
cases we want to use upstream perf on it) have the slang header files in
/usr/include/slang/, so add a test that will be performed only when
test-all.c (the one with the most common sane settings) fails, either
because we're in one of these odd distros with slang/slang.h or because
something else failed (say libelf is not present).
So for the common case nothing changes, no additional test is performed.
Next step is to check in perf the result of these tests.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Fixes: 1955c8cf5e ("perf tools: Don't hardcode host include path for libslang")
Link: https://lkml.kernel.org/n/tip-2sy7hbwkx68jr6n97qxgg0c6@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Test that the offload indication for unicast routes is correctly set in
different scenarios. IPv4 support will be added in the future.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds the test cases for checking compressed firmware load.
Two more cases are added to fw_filesystem.sh:
- Both a plain file and an xz file are present, and load the former
- Only an xz file is present, and load without '.xz' suffix
The tests are enabled only when CONFIG_FW_LOADER_COMPRESS is enabled
and xz program is installed.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Ensure that failure on any individual test results in an overall
failure of the test script.
Signed-off-by: Fred Klassen <fklassen@appneta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Audit tests count the total number of messages sent and compares
with total number of CMSG received on error queue. Example:
udp gso zerocopy timestamp audit
udp rx: 1599 MB/s 1166414 calls/s
udp tx: 1615 MB/s 27395 calls/s 27395 msg/s
udp rx: 1634 MB/s 1192261 calls/s
udp tx: 1633 MB/s 27699 calls/s 27699 msg/s
udp rx: 1633 MB/s 1191358 calls/s
udp tx: 1631 MB/s 27678 calls/s 27678 msg/s
Summary over 4.000 seconds...
sum udp tx: 1665 MB/s 82772 calls (27590/s) 82772 msgs (27590/s)
Tx Timestamps: 82772 received 0 errors
Zerocopy acks: 82772 received
Errors are thrown if CMSG count does not equal send count,
example:
Summary over 4.000 seconds...
sum tcp tx: 7451 MB/s 493706 calls (123426/s) 493706 msgs (123426/s)
./udpgso_bench_tx: Unexpected number of Zerocopy completions: 493706 expected 493704 received
Also reduce individual test time from 4 to 3 seconds so that
overall test time does not increase significantly.
v3: Enhancements as per Willem de Bruijn <willemb@google.com>
- document -P option for TCP audit
Signed-off-by: Fred Klassen <fklassen@appneta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This enhancement adds options that facilitate load testing with
additional TX CMSG options, and to optionally print results of
various send CMSG operations.
These options are especially useful in isolating situations
where error-queue messages are lost when combined with other
CMSG operations (e.g. SO_ZEROCOPY).
New options:
-a - count all CMSG messages and match to sent messages
-T - add TX CMSG that requests TX software timestamps
-H - similar to -T except request TX hardware timestamps
-P - call poll() before reading error queue
-v - print detailed results
v2: Enhancements as per Willem de Bruijn <willemb@google.com>
- Updated control and buffer parameters for recvmsg
- poll() parameter cleanup
- fail on bad audit results
- remove TOS options
- improved reporting
v3: Enhancements as per Willem de Bruijn <willemb@google.com>
- add SOF_TIMESTAMPING_OPT_TSONLY to eliminate MSG_TRUNC
- general code cleanup
Signed-off-by: Fred Klassen <fklassen@appneta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This exercises kernel code path that deal with addresses that have
a limited lifetime.
Without previous fix, this triggers following crash on net-next:
BUG: KASAN: null-ptr-deref in check_lifetime+0x403/0x670
Read of size 8 at addr 0000000000000010 by task kworker [..]
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull networking fixes from David Miller:
"Lots of bug fixes here:
1) Out of bounds access in __bpf_skc_lookup, from Lorenz Bauer.
2) Fix rate reporting in cfg80211_calculate_bitrate_he(), from John
Crispin.
3) Use after free in psock backlog workqueue, from John Fastabend.
4) Fix source port matching in fdb peer flow rule of mlx5, from Raed
Salem.
5) Use atomic_inc_not_zero() in fl6_sock_lookup(), from Eric Dumazet.
6) Network header needs to be set for packet redirect in nfp, from
John Hurley.
7) Fix udp zerocopy refcnt, from Willem de Bruijn.
8) Don't assume linear buffers in vxlan and geneve error handlers,
from Stefano Brivio.
9) Fix TOS matching in mlxsw, from Jiri Pirko.
10) More SCTP cookie memory leak fixes, from Neil Horman.
11) Fix VLAN filtering in rtl8366, from Linus Walluij.
12) Various TCP SACK payload size and fragmentation memory limit fixes
from Eric Dumazet.
13) Use after free in pneigh_get_next(), also from Eric Dumazet.
14) LAPB control block leak fix from Jeremy Sowden"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (145 commits)
lapb: fixed leak of control-blocks.
tipc: purge deferredq list for each grp member in tipc_group_delete
ax25: fix inconsistent lock state in ax25_destroy_timer
neigh: fix use-after-free read in pneigh_get_next
tcp: fix compile error if !CONFIG_SYSCTL
hv_sock: Suppress bogus "may be used uninitialized" warnings
be2net: Fix number of Rx queues used for flow hashing
net: handle 802.1P vlan 0 packets properly
tcp: enforce tcp_min_snd_mss in tcp_mtu_probing()
tcp: add tcp_min_snd_mss sysctl
tcp: tcp_fragment() should apply sane memory limits
tcp: limit payload size of sacked skbs
Revert "net: phylink: set the autoneg state in phylink_phy_change"
bpf: fix nested bpf tracepoints with per-cpu data
bpf: Fix out of bounds memory access in bpf_sk_storage
vsock/virtio: set SOCK_DONE on peer shutdown
net: dsa: rtl8366: Fix up VLAN filtering
net: phylink: set the autoneg state in phylink_phy_change
net: add high_order_alloc_disable sysctl/static key
tcp: add tcp_tx_skb_cache sysctl
...
Convert a bulk of selftests that have maps with custom (not integer) key
and/or value.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This patch adds support for a new way to define BPF maps. It relies on
BTF to describe mandatory and optional attributes of a map, as well as
captures type information of key and value naturally. This eliminates
the need for BPF_ANNOTATE_KV_PAIR hack and ensures key/value sizes are
always in sync with the key/value type.
Relying on BTF, this approach allows for both forward and backward
compatibility w.r.t. extending supported map definition features. By
default, any unrecognized attributes are treated as an error, but it's
possible relax this using MAPS_RELAX_COMPAT flag. New attributes, added
in the future will need to be optional.
The outline of the new map definition (short, BTF-defined maps) is as follows:
1. All the maps should be defined in .maps ELF section. It's possible to
have both "legacy" map definitions in `maps` sections and BTF-defined
maps in .maps sections. Everything will still work transparently.
2. The map declaration and initialization is done through
a global/static variable of a struct type with few mandatory and
extra optional fields:
- type field is mandatory and specified type of BPF map;
- key/value fields are mandatory and capture key/value type/size information;
- max_entries attribute is optional; if max_entries is not specified or
initialized, it has to be provided in runtime through libbpf API
before loading bpf_object;
- map_flags is optional and if not defined, will be assumed to be 0.
3. Key/value fields should be **a pointer** to a type describing
key/value. The pointee type is assumed (and will be recorded as such
and used for size determination) to be a type describing key/value of
the map. This is done to save excessive amounts of space allocated in
corresponding ELF sections for key/value of big size.
4. As some maps disallow having BTF type ID associated with key/value,
it's possible to specify key/value size explicitly without
associating BTF type ID with it. Use key_size and value_size fields
to do that (see example below).
Here's an example of simple ARRAY map defintion:
struct my_value { int x, y, z; };
struct {
int type;
int max_entries;
int *key;
struct my_value *value;
} btf_map SEC(".maps") = {
.type = BPF_MAP_TYPE_ARRAY,
.max_entries = 16,
};
This will define BPF ARRAY map 'btf_map' with 16 elements. The key will
be of type int and thus key size will be 4 bytes. The value is struct
my_value of size 12 bytes. This map can be used from C code exactly the
same as with existing maps defined through struct bpf_map_def.
Here's an example of STACKMAP definition (which currently disallows BTF type
IDs for key/value):
struct {
__u32 type;
__u32 max_entries;
__u32 map_flags;
__u32 key_size;
__u32 value_size;
} stackmap SEC(".maps") = {
.type = BPF_MAP_TYPE_STACK_TRACE,
.max_entries = 128,
.map_flags = BPF_F_STACK_BUILD_ID,
.key_size = sizeof(__u32),
.value_size = PERF_MAX_STACK_DEPTH * sizeof(struct bpf_stack_build_id),
};
This approach is naturally extended to support map-in-map, by making a value
field to be another struct that describes inner map. This feature is not
implemented yet. It's also possible to incrementally add features like pinning
with full backwards and forward compatibility. Support for static
initialization of BPF_MAP_TYPE_PROG_ARRAY using pointers to BPF programs
is also on the roadmap.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Libbpf does sanitization of BTF before loading it into kernel, if kernel
doesn't support some of newer BTF features. This removes some of the
important information from BTF (e.g., DATASEC and VAR description),
which will be used for map construction. This patch splits BTF
processing into initialization step, in which BTF is initialized from
ELF and all the original data is still preserved; and
sanitization/loading step, which ensures that BTF is safe to load into
kernel. This allows to use full BTF information to construct maps, while
still loading valid BTF into older kernels.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
