We recently updated bpftool's Makefile to make it install the headers
from libbpf, instead of pulling them directly from libbpf's directory.
There is also an additional header, internal to libbpf, that needs be
installed. The way that bpftool's Makefile installs that particular
header is currently correct, but would break if we were to modify
$(LIBBPF_INTERNAL_HDRS) to make it point to more than one header.
Use a static pattern rule instead, so that the Makefile can withstand
the addition of other headers to install.
The objective is simply to make the Makefile more robust. It should
_not_ be read as an invitation to import more internal headers from
libbpf into bpftool.
Fixes: f012ade10b ("bpftool: Install libbpf headers instead of including the dir")
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20211009210341.6291-2-quentin@isovalent.com
Although relying on some definitions from the netlink.h and if_link.h
headers copied into tools/include/uapi/linux/, libbpf does not need
those headers to stay entirely up-to-date with their original versions,
and the warnings emitted by the Makefile when it detects a difference
are usually just noise. Let's remove those warnings.
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211010002528.9772-1-quentin@isovalent.com
Patch set [1] introduced BTF_KIND_TAG to allow tagging
declarations for struct/union, struct/union field, var, func
and func arguments and these tags will be encoded into
dwarf. They are also encoded to btf by llvm for the bpf target.
After BTF_KIND_TAG is introduced, we intended to use it
for kernel __user attributes. But kernel __user is actually
a type attribute. Upstream and internal discussion showed
it is not a good idea to mix declaration attribute and
type attribute. So we proposed to introduce btf_type_tag
as a type attribute and existing btf_tag renamed to
btf_decl_tag ([2]).
This patch renamed BTF_KIND_TAG to BTF_KIND_DECL_TAG and some
other declarations with *_tag to *_decl_tag to make it clear
the tag is for declaration. In the future, BTF_KIND_TYPE_TAG
might be introduced per [3].
[1] https://lore.kernel.org/bpf/20210914223004.244411-1-yhs@fb.com/
[2] https://reviews.llvm.org/D111588
[3] https://reviews.llvm.org/D111199
Fixes: b5ea834dde ("bpf: Support for new btf kind BTF_KIND_TAG")
Fixes: 5b84bd1036 ("libbpf: Add support for BTF_KIND_TAG")
Fixes: 5c07f2fec0 ("bpftool: Add support for BTF_KIND_TAG")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211012164838.3345699-1-yhs@fb.com
In emit_tail_call() of bpf_jit_comp32.c, "blez t2" (t2 <= 0) is
not consistent with the comment "t2 < 0", update the comment to
keep consistency.
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Link: https://lore.kernel.org/bpf/1633915150-13220-3-git-send-email-yangtiezhu@loongson.cn
The config options MIPS_CBPF_JIT and MIPS_EBPF_JIT are useless, remove
them in arch/mips/Kconfig, and then modify arch/mips/net/Makefile.
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Link: https://lore.kernel.org/bpf/1633915150-13220-2-git-send-email-yangtiezhu@loongson.cn
The verifier tests added in commit c48e51c8b0 ("bpf: selftests: Add
selftests for module kfunc support") fail on s390, since the JIT does
not support calling kernel functions. This is most likely an issue for
all the other non-Intel arches, as well as on Intel with
!CONFIG_DEBUG_INFO_BTF or !CONFIG_BPF_JIT.
Trying to check for messages from all the possible add_kfunc_call()
failure cases in test_verifier looks pointless, so do a much simpler
thing instead: just like it's already done in do_prog_test_run(), skip
the tests that fail to load with ENOTSUPP.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211007173329.381754-1-iii@linux.ibm.com
Yucong Sun says:
====================
This patch series adds "-j" parelell execution to test_progs, with "--debug" to
display server/worker communications. Also, some Tests that often fails in
parallel are marked as serial test, and it will run in sequence after parallel
execution is done.
This patch series also adds a error summary after all tests execution finished.
V6 -> V5:
* adding error summary logic for non parallel mode too.
* changed how serial tests are implemented, use main process instead of worker 0.
* fixed a dozen broken test when running in parallel.
V5 -> V4:
* change to SOCK_SEQPACKET for close notification.
* move all debug output to "--debug" mode
* output log as test finish, and all error logs again after summary line.
* variable naming / style changes
* adds serial_test_name() to replace serial test lists.
====================
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
bpf_get_current_pid_tgid() returns u64, whose upper 32 bits are the same
as userspace getpid() return value.
Signed-off-by: Yucong Sun <sunyucong@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211006185619.364369-13-fallentree@fb.com
This patch make each worker use a unique cgroup base directory, thus
allowing tests that uses cgroups to run concurrently.
Signed-off-by: Yucong Sun <sunyucong@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211006185619.364369-5-fallentree@fb.com
This patch allows tests to define serial_test_name() instead of
test_name(), and this will make test_progs execute those in sequence
after all other tests finished executing concurrently.
Signed-off-by: Yucong Sun <sunyucong@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211006185619.364369-3-fallentree@fb.com
This patch adds "-j" mode to test_progs, executing tests in multiple
process. "-j" mode is optional, and works with all existing test
selection mechanism, as well as "-v", "-l" etc.
In "-j" mode, main process use UDS/SEQPACKET to communicate to each forked
worker, commanding it to run tests and collect logs. After all tests are
finished, a summary is printed. main process use multiple competing
threads to dispatch work to worker, trying to keep them all busy.
The test status will be printed as soon as it is finished, if there are
error logs, it will be printed after the final summary line.
By specifying "--debug", additional debug information on server/worker
communication will be printed.
Example output:
> ./test_progs -n 15-20 -j
[ 12.801730] bpf_testmod: loading out-of-tree module taints kernel.
Launching 8 workers.
#20 btf_split:OK
#16 btf_endian:OK
#18 btf_module:OK
#17 btf_map_in_map:OK
#19 btf_skc_cls_ingress:OK
#15 btf_dump:OK
Summary: 6/20 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: Yucong Sun <sunyucong@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211006185619.364369-2-fallentree@fb.com
Hou Tao says:
====================
From: Hou Tao <houtao1@huawei.com>
Hi,
The patchset series supports writable context for bare tracepoint.
The main idea comes from patchset "writable contexts for bpf raw
tracepoints" [1], but it only supports normal tracepoint with
associated trace event under tracefs. Now we have one use case
in which we add bare tracepoint in VFS layer, and update
file::f_mode for specific files. The reason using bare tracepoint
is that it doesn't form a ABI and we can change it freely. So
add support for it in BPF.
Comments are always welcome.
[1]: https://lore.kernel.org/lkml/20190426184951.21812-1-mmullins@fb.com
Change log:
v5:
* rebased on bpf-next
* patch 1: add Acked-by tag
* patch 2: handle invalid section name, make prefixes array being const
v4: https://www.spinics.net/lists/bpf/msg47021.html
* rebased on bpf-next
* update patch 2 to add support for writable raw tracepoint attachment
in attach_raw_tp().
* update patch 3 to add Acked-by tag
v3: https://www.spinics.net/lists/bpf/msg46824.html
* use raw_tp.w instead of raw_tp_writable as section
name of writable tp
* use ASSERT_XXX() instead of CHECK()
* define a common macro for "/sys/kernel/bpf_testmod"
v2: https://www.spinics.net/lists/bpf/msg46356.html
* rebase on bpf-next tree
* address comments from Yonghong Song
* rename bpf_testmode_test_writable_ctx::ret as early_ret to reflect
its purpose better.
v1: https://www.spinics.net/lists/bpf/msg46221.html
====================
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Add a writable bare tracepoint in bpf_testmod module, and
trigger its calling when reading /sys/kernel/bpf_testmod
with a specific buffer length. The reading will return
the value in writable context if the early return flag
is enabled in writable context.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211004094857.30868-4-hotforest@gmail.com
Program on writable tracepoint is BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE,
but its attachment is the same as BPF_PROG_TYPE_RAW_TRACEPOINT.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211004094857.30868-3-hotforest@gmail.com
Commit 9df1c28bb7 ("bpf: add writable context for raw tracepoints")
supports writable context for tracepoint, but it misses the support
for bare tracepoint which has no associated trace event.
Bare tracepoint is defined by DECLARE_TRACE(), so adding a corresponding
DECLARE_TRACE_WRITABLE() macro to generate a definition in __bpf_raw_tp_map
section for bare tracepoint in a similar way to DEFINE_TRACE_WRITABLE().
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211004094857.30868-2-hotforest@gmail.com
Quentin Monnet says:
====================
Libbpf is used at several locations in the repository. Most of the time,
the tools relying on it build the library in its own directory, and include
the headers from there. This works, but this is not the cleanest approach.
It generates objects outside of the directory of the tool which is being
built, and it also increases the risk that developers include a header file
internal to libbpf, which is not supposed to be exposed to user
applications.
This set adjusts all involved Makefiles to make sure that libbpf is built
locally (with respect to the tool's directory or provided build directory),
and by ensuring that "make install_headers" is run from libbpf's Makefile
to export user headers properly.
This comes at a cost: given that the libbpf was so far mostly compiled in
its own directory by the different components using it, compiling it once
would be enough for all those components. With the new approach, each
component compiles its own version. To mitigate this cost, efforts were
made to reuse the compiled library when possible:
- Make the bpftool version in samples/bpf reuse the library previously
compiled for the selftests.
- Make the bpftool version in BPF selftests reuse the library previously
compiled for the selftests.
- Similarly, make resolve_btfids in BPF selftests reuse the same compiled
library.
- Similarly, make runqslower in BPF selftests reuse the same compiled
library; and make it rely on the bpftool version also compiled from the
selftests (instead of compiling its own version).
- runqslower, when compiled independently, needs its own version of
bpftool: make them share the same compiled libbpf.
As a result:
- Compiling the samples/bpf should compile libbpf just once.
- Compiling the BPF selftests should compile libbpf just once.
- Compiling the kernel (with BTF support) should now lead to compiling
libbpf twice: one for resolve_btfids, one for kernel/bpf/preload.
- Compiling runqslower individually should compile libbpf just once. Same
thing for bpftool, resolve_btfids, and kernel/bpf/preload/iterators.
(Not accounting for the boostrap version of libbpf required by bpftool,
which was already placed under a dedicated .../boostrap/libbpf/ directory,
and for which the count remains unchanged.)
A few commits in the series also contain drive-by clean-up changes for
bpftool includes, samples/bpf/.gitignore, or test_bpftool_build.sh. Please
refer to individual commit logs for details.
v4:
- Make the "libbpf_hdrs" dependency an order-only dependency in
kernel/bpf/preload/Makefile, samples/bpf/Makefile, and
tools/bpf/runqslower/Makefile. This is to avoid to unconditionally
recompile the targets.
- samples/bpf/.gitignore: prefix objects with a "/" to mark that we
ignore them when at the root of the samples/bpf/ directory.
- libbpf: add a commit to make "install_headers" depend on the header
files, to avoid exporting again if the sources are older than the
targets. This ensures that applications relying on those headers are
not rebuilt unnecessarily.
- bpftool: uncouple the copy of nlattr.h from libbpf target, to have it
depend on the source header itself. By avoiding to reinstall this
header every time, we avoid unnecessary builds of bpftool.
- samples/bpf: Add a new commit to remove the FORCE dependency for
libbpf, and replace it with a "$(wildcard ...)" on the .c/.h files in
libbpf's directory. This is to avoid always recompiling libbpf/bpftool.
- Adjust prefixes in commit subjects.
v3:
- Remove order-only dependencies on $(LIBBPF_INCLUDE) (or equivalent)
directories, given that they are created by libbpf's Makefile.
- Add libbpf as a dependency for bpftool/resolve_btfids/runqslower when
they are supposed to reuse a libbpf compiled previously. This is to
avoid having several libbpf versions being compiled simultaneously in
the same directory with parallel builds. Even if this didn't show up
during tests, let's remain on the safe side.
- kernel/bpf/preload/Makefile: Rename libbpf-hdrs (dash) dependency as
libbpf_hdrs.
- samples/bpf/.gitignore: Add bpftool/
- samples/bpf/Makefile: Change "/bin/rm -rf" to "$(RM) -r".
- samples/bpf/Makefile: Add missing slashes for $(LIBBPF_OUTPUT) and
$(LIBBPF_DESTDIR) when buildling bpftool
- samples/bpf/Makefile: Add a dependency to libbpf's headers for
$(TRACE_HELPERS).
- bpftool's Makefile: Use $(LIBBPF) instead of equivalent (but longer)
$(LIBBPF_OUTPUT)libbpf.a
- BPF iterators' Makefile: build bpftool in .output/bpftool (instead of
.output/), add and clean up variables.
- runqslower's Makefile: Add an explicit dependency on libbpf's headers
to several objects. The dependency is not required (libbpf should have
been compiled and so the headers exported through other dependencies
for those targets), but they better mark the logical dependency and
should help if exporting the headers changed in the future.
- New commit to add an "install-bin" target to bpftool, to avoid
installing bash completion when buildling BPF iterators and selftests.
v2: Declare an additional dependency on libbpf's headers for
iterators/iterators.o in kernel/preload/Makefile to make sure that
these headers are exported before we compile the object file (and not
just before we link it).
====================
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
With "make install", bpftool installs its binary and its bash completion
file. Usually, this is what we want. But a few components in the kernel
repository (namely, BPF iterators and selftests) also install bpftool
locally before using it. In such a case, bash completion is not
necessary and is just a useless build artifact.
Let's add an "install-bin" target to bpftool, to offer a way to install
the binary only.
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007194438.34443-13-quentin@isovalent.com
The script test_bpftool_build.sh attempts to build bpftool in the
various supported ways, to make sure nothing breaks.
One of those ways is to run "make tools/bpf" from the root of the kernel
repository. This command builds bpftool, along with the other tools
under tools/bpf, and runqslower in particular. After running the
command and upon a successful bpftool build, the script attempts to
cleanup the generated objects. However, after building with this target
and in the case of runqslower, the files are not cleaned up as expected.
This is because the "tools/bpf" target sets $(OUTPUT) to
.../tools/bpf/runqslower/ when building the tool, causing the object
files to be placed directly under the runqslower directory. But when
running "cd tools/bpf; make clean", the value for $(OUTPUT) is set to
".output" (relative to the runqslower directory) by runqslower's
Makefile, and this is where the Makefile looks for files to clean up.
We cannot easily fix in the root Makefile (where "tools/bpf" is defined)
or in tools/scripts/Makefile.include (setting $(OUTPUT)), where changing
the way the output variables are passed would likely have consequences
elsewhere. We could change runqslower's Makefile to build in the
repository instead of in a dedicated ".output/", but doing so just to
accommodate a test script doesn't sound great. Instead, let's just make
sure that we clean up runqslower properly by adding the correct command
to the script.
This will attempt to clean runqslower twice: the first try with command
"cd tools/bpf; make clean" will search for tools/bpf/runqslower/.output
and fail to clean it (but will still clean the other tools, in
particular bpftool), the second one (added in this commit) sets the
$(OUTPUT) variable like for building with the "tool/bpf" target and
should succeed.
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007194438.34443-12-quentin@isovalent.com
In samples/bpf/Makefile, libbpf has a FORCE dependency that force it to
be rebuilt. I read this as a way to keep the library up-to-date, given
that we do not have, in samples/bpf, a list of the source files for
libbpf itself. However, a better approach would be to use the
"$(wildcard ...)" function from make, and to have libbpf depend on all
the .c and .h files in its directory. This is what samples/bpf/Makefile
does for bpftool, and also what the BPF selftests' Makefile does for
libbpf.
Let's update the Makefile to avoid rebuilding libbpf all the time (and
bpftool on top of it).
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007194438.34443-11-quentin@isovalent.com
API headers from libbpf should not be accessed directly from the source
directory. Instead, they should be exported with "make install_headers".
Make sure that samples/bpf/Makefile installs the headers properly when
building.
The object compiled from and exported by libbpf are now placed into a
subdirectory of sample/bpf/ instead of remaining in tools/lib/bpf/. We
attempt to remove this directory on "make clean". However, the "clean"
target re-enters the samples/bpf/ directory from the root of the
repository ("$(MAKE) -C ../../ M=$(CURDIR) clean"), in such a way that
$(srctree) and $(src) are not defined, making it impossible to use
$(LIBBPF_OUTPUT) and $(LIBBPF_DESTDIR) in the recipe. So we only attempt
to clean $(CURDIR)/libbpf, which is the default value.
Add a dependency on libbpf's headers for the $(TRACE_HELPERS).
We also change the output directory for bpftool, to place the generated
objects under samples/bpf/bpftool/ instead of building in bpftool's
directory directly. Doing so, we make sure bpftool reuses the libbpf
library previously compiled and installed.
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007194438.34443-10-quentin@isovalent.com
Update samples/bpf/.gitignore to ignore files generated when building
the samples. Add:
- vmlinux.h
- the generated skeleton files (*.skel.h)
- the samples/bpf/libbpf/ and .../bpftool/ directories, in preparation
of a future commit which introduces a local output directory for
building libbpf and bpftool.
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007194438.34443-9-quentin@isovalent.com
API headers from libbpf should not be accessed directly from the
library's source directory. Instead, they should be exported with "make
install_headers". Let's make sure that bpf/preload/iterators/Makefile
installs the headers properly when building.
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007194438.34443-8-quentin@isovalent.com
API headers from libbpf should not be accessed directly from the
library's source directory. Instead, they should be exported with "make
install_headers". Let's make sure that bpf/preload/Makefile installs the
headers properly when building.
Note that we declare an additional dependency for iterators/iterators.o:
having $(LIBBPF_A) as a dependency to "$(obj)/bpf_preload_umd" is not
sufficient, as it makes it required only at the linking step. But we
need libbpf to be compiled, and in particular its headers to be
exported, before we attempt to compile iterators.o. The issue would not
occur before this commit, because libbpf's headers were not exported and
were always available under tools/lib/bpf.
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007194438.34443-7-quentin@isovalent.com
API headers from libbpf should not be accessed directly from the
library's source directory. Instead, they should be exported with "make
install_headers". Let's make sure that runqslower installs the
headers properly when building.
We use a libbpf_hdrs target to mark the logical dependency on libbpf's
headers export for a number of object files, even though the headers
should have been exported at this time (since bpftool needs them, and is
required to generate the skeleton or the vmlinux.h).
When descending from a parent Makefile, the specific output directories
for building the library and exporting the headers are configurable with
BPFOBJ_OUTPUT and BPF_DESTDIR, respectively. This is in addition to
OUTPUT, on top of which those variables are constructed by default.
Also adjust the Makefile for the BPF selftests. We pass a number of
variables to the "make" invocation, because we want to point runqslower
to the (target) libbpf shared with other tools, instead of building its
own version. In addition, runqslower relies on (target) bpftool, and we
also want to pass the proper variables to its Makefile so that bpftool
itself reuses the same libbpf.
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007194438.34443-6-quentin@isovalent.com
API headers from libbpf should not be accessed directly from the
library's source directory. Instead, they should be exported with "make
install_headers". Let's make sure that resolve_btfids installs the
headers properly when building.
When descending from a parent Makefile, the specific output directories
for building the library and exporting the headers are configurable with
LIBBPF_OUT and LIBBPF_DESTDIR, respectively. This is in addition to
OUTPUT, on top of which those variables are constructed by default.
Also adjust the Makefile for the BPF selftests in order to point to the
(target) libbpf shared with other tools, instead of building a version
specific to resolve_btfids. Remove libbpf's order-only dependencies on
the include directories (they are created by libbpf and don't need to
exist beforehand).
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007194438.34443-5-quentin@isovalent.com
Bpftool relies on libbpf, therefore it relies on a number of headers
from the library and must be linked against the library. The Makefile
for bpftool exposes these objects by adding tools/lib as an include
directory ("-I$(srctree)/tools/lib"). This is a working solution, but
this is not the cleanest one. The risk is to involuntarily include
objects that are not intended to be exposed by the libbpf.
The headers needed to compile bpftool should in fact be "installed" from
libbpf, with its "install_headers" Makefile target. In addition, there
is one header which is internal to the library and not supposed to be
used by external applications, but that bpftool uses anyway.
Adjust the Makefile in order to install the header files properly before
compiling bpftool. Also copy the additional internal header file
(nlattr.h), but call it out explicitly. Build (and install headers) in a
subdirectory under bpftool/ instead of tools/lib/bpf/. When descending
from a parent Makefile, this is configurable by setting the OUTPUT,
LIBBPF_OUTPUT and LIBBPF_DESTDIR variables.
Also adjust the Makefile for BPF selftests, so as to reuse the (host)
libbpf compiled earlier and to avoid compiling a separate version of the
library just for bpftool.
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007194438.34443-4-quentin@isovalent.com
It seems that the header file was never necessary to compile bpftool,
and it is not part of the headers exported from libbpf. Let's remove the
includes from prog.c and gen.c.
Fixes: d510296d33 ("bpftool: Use syscall/loader program in "prog load" and "gen skeleton" command.")
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007194438.34443-3-quentin@isovalent.com
The "install_headers" target in libbpf's Makefile would unconditionally
export all API headers to the target directory. When those headers are
installed to compile another application, this means that make always
finds newer dependencies for the source files relying on those headers,
and deduces that the targets should be rebuilt.
Avoid that by making "install_headers" depend on the source header
files, and (re-)install them only when necessary.
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007194438.34443-2-quentin@isovalent.com
Since commit 6c4fc209fc ("bpf: remove useless version check for prog
load") these "version" sections, which result in bpf_attr.kern_version
being set, have been unnecessary.
Remove them so that it's obvious to folks using selftests as a guide that
"modern" BPF progs don't need this section.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007231234.2223081-1-davemarchevsky@fb.com
VMs running on upstream 5.12+ kernel support LBR. However,
bpf_get_branch_snapshot couldn't stop the LBR before too many entries
are flushed. Skip the hit/waste test for VMs before we find a proper fix
for LBR in VM.
Fixes: 025bd7c753 ("selftests/bpf: Add test for bpf_get_branch_snapshot")
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007050231.728496-1-songliubraving@fb.com
This patch adds new tests for the two-instruction LD_IMM64. The new tests
verify the operation with immediate values of different byte patterns.
Mainly intended to cover JITs that want to be clever when loading 64-bit
constants.
Signed-off-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211007143006.634308-1-johan.almbladh@anyfinetworks.com
This patch shaves off a few instructions when loading sparse 64-bit
constants to register. The change is covered by additional tests in
lib/test_bpf.c.
Signed-off-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211007142828.634182-1-johan.almbladh@anyfinetworks.com
Introduce a single reg version of maybe_emit_mod() and factor out
common code in more cases.
Signed-off-by: Jie Meng <jmeng@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211006194135.608932-1-jmeng@fb.com
Hengqi Chen says:
====================
bpf_{map,program}__{prev,next} don't follow the libbpf API naming
convention. Deprecate them and replace them with a new set of APIs
named bpf_object__{prev,next}_{program,map}.
v1->v2: [0]
* Addressed Andrii's comments
[0]: https://patchwork.kernel.org/project/netdevbpf/patch/20210906165456.325999-1-hengqi.chen@gmail.com/
====================
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
BPF objects are not reloadable after unload. Users are expected to use
bpf_object__close() to unload and free up resources in one operation.
No need to expose bpf_object__unload() as a public API, deprecate it
([0]). Add bpf_object__unload() as an alias to internal
bpf_object_unload() and replace all bpf_object__unload() uses to avoid
compilation errors.
[0] Closes: https://github.com/libbpf/libbpf/issues/290
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211002161000.3854559-1-hengqi.chen@gmail.com
Replace deprecated bpf_{map,program}__next APIs with newly added
bpf_object__next_{map,program} APIs, so that no compilation warnings
emit.
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211003165844.4054931-3-hengqi.chen@gmail.com
This adds a section to the documentation for libbpf
naming convention which describes how to document
API features in libbpf, specifically the format of
which API doc comments need to conform to.
Signed-off-by: Grant Seltzer <grantseltzer@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211004215644.497327-1-grantseltzer@gmail.com
Deprecate bpf_{map,program}__{prev,next} APIs. Replace them with
a new set of APIs named bpf_object__{prev,next}_{program,map} which
follow the libbpf API naming convention ([0]). No functionality changes.
[0] Closes: https://github.com/libbpf/libbpf/issues/296
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211003165844.4054931-2-hengqi.chen@gmail.com
Currently the recursion test is hooking __htab_map_lookup_elem
function, which is invoked both from bpf_prog and bpf syscall.
But in our kernel build, the __htab_map_lookup_elem gets inlined
within the htab_map_lookup_elem, so it's not trigered and the
test fails.
Fixing this by using htab_map_delete_elem, which is not inlined
for bpf_prog calls (like htab_map_lookup_elem is) and is used
directly as pointer for map_delete_elem, so it won't disappear
by inlining.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/YVnfFTL/3T6jOwHI@krava
Recent-ish versions of make do no longer consider number signs ("#") as
comment symbols when they are inserted inside of a macro reference or in
a function invocation. In such cases, the symbols should not be escaped.
There are a few occurrences of "\#" in libbpf's and samples' Makefiles.
In the former, the backslash is harmless, because grep associates no
particular meaning to the escaped symbol and reads it as a regular "#".
In samples' Makefile, recent versions of make will pass the backslash
down to the compiler, making the probe fail all the time and resulting
in the display of a warning about "make headers_install" being required,
even after headers have been installed.
A similar issue has been addressed at some other locations by commit
9564a8cf42 ("Kbuild: fix # escaping in .cmd files for future Make").
Let's address it for libbpf's and samples' Makefiles in the same
fashion, by using a "$(pound)" variable (pulled from
tools/scripts/Makefile.include for libbpf, or re-defined for the
samples).
Reference for the change in make:
https://git.savannah.gnu.org/cgit/make.git/commit/?id=c6966b323811c37acedff05b57
Fixes: 2f38304127 ("libbpf: Make libbpf_version.h non-auto-generated")
Fixes: 07c3bbdb1a ("samples: bpf: print a warning about headers_install")
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211006111049.20708-1-quentin@isovalent.com
The BPF core defines a __weak bpf_jit_compile() dummy function already
which should only be overridden by JITs if they actually implement a
legacy cBPF JIT. Given arm implements an eBPF JIT, this stub is not
needed.
Now that MIPS cBPF JIT is finally gone, the only JIT left that is still
implementing bpf_jit_compile() is the sparc32 one.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Johan Almbladh says:
====================
This is an implementation of an eBPF JIT for MIPS I-V and MIPS32/64 r1-r6.
The new JIT is written from scratch, but uses the same overall structure
as other eBPF JITs.
Before, the MIPS JIT situation looked like this.
- 32-bit: MIPS32, cBPF-only, tests fail
- 64-bit: MIPS64r2-r6, eBPF, tests fail, incomplete eBPF ISA support
The new JIT implementation raises the bar to the following level.
- 32/64-bit: all MIPS ISA, eBPF, all tests pass, full eBPF ISA support
Overview
--------
The implementation supports all 32-bit and 64-bit eBPF instructions
defined as of this writing, including the recently-added atomics. It is
intended to provide good performance for native word size operations,
while also being complete so the JIT never has to fall back to the
interpreter. The new JIT replaces the current cBPF and eBPF JITs for MIPS.
The implementation is divided into separate files as follows. The source
files contains comments describing internal mechanisms and details on
things like eBPF-to-CPU register mappings, so I won't repeat that here.
- jit_comp.[ch] code shared between 32-bit and 64-bit JITs
- jit_comp32.c 32-bit JIT implementation
- jit_comp64.c 64-bit JIT implementation
Both the 32-bit and 64-bit versions map all eBPF registers to native MIPS
CPU registers. There are also enough unmapped CPU registers available to
allow all eBPF operations implemented natively by the JIT to use only CPU
registers without having to resort to stack scratch space.
Some operations are deemed too complex to implement natively in the JIT.
Those are instead implemented as a function call to a helper that performs
the operation. This is done in the following cases.
- 64-bit div and mod on a 32-bit CPU
- 64-bit atomics on a 32-bit CPU
- 32-bit atomics on a 32-bit CPU that lacks ll/sc instructions
CPU errata workarounds
----------------------
The JIT implements workarounds for R10000, Loongson-2F and Loongson-3 CPU
errata. For the Loongson workarounds, I have used the public information
available on the matter.
Link: https://sourceware.org/legacy-ml/binutils/2009-11/msg00387.html
Testing
-------
During the development of the JIT, I have added a number of new test cases
to the test_bpf.ko test suite to be able to verify correctness of JIT
implementations in a more systematic way. The new additions increase the
test suite roughly three-fold, with many of the new tests being very
extensive and even exhaustive when feasible.
Link: https://lore.kernel.org/bpf/20211001130348.3670534-1-johan.almbladh@anyfinetworks.com/
Link: https://lore.kernel.org/bpf/20210914091842.4186267-1-johan.almbladh@anyfinetworks.com/
Link: https://lore.kernel.org/bpf/20210809091829.810076-1-johan.almbladh@anyfinetworks.com/
The JIT has been tested by running the test_bpf.ko test suite in QEMU with
the following MIPS ISAs, in both big and little endian mode, with and
without JIT hardening enabled.
MIPS32r2, MIPS32r6, MIPS64r2, MIPS64r6
For the QEMU r2 targets, the correctness of pre-r2 code emitted has been
tested by manually overriding each of the following macros with 0.
cpu_has_llsc, cpu_has_mips_2, cpu_has_mips_r1, cpu_has_mips_r2
Similarly, CPU errata workaround code has been tested by enabling the
each of the following configurations for the MIPS64r2 targets.
CONFIG_WAR_R10000
CONFIG_CPU_LOONGSON3_WORKAROUNDS
CONFIG_CPU_NOP_WORKAROUNDS
CONFIG_CPU_JUMP_WORKAROUNDS
The JIT passes all tests in all configurations. Below is the summary for
MIPS32r2 in little endian mode.
test_bpf: Summary: 1006 PASSED, 0 FAILED, [994/994 JIT'ed]
test_bpf: test_tail_calls: Summary: 8 PASSED, 0 FAILED, [8/8 JIT'ed]
test_bpf: test_skb_segment: Summary: 2 PASSED, 0 FAILED
According to MIPS ISA reference documentation, the result of a 32-bit ALU
arithmetic operation on a 64-bit CPU is unpredictable if an operand
register value is not properly sign-extended to 64 bits. To verify the
code emitted by the JIT, the code generation engine in QEMU was modifed to
flip all low 32 bits if the above condition was not met. With this
trip-wire installed, the kernel booted properly in qemu-system-mips64el
and all test_bpf.ko tests passed.
Remaining features
------------------
While the JIT is complete is terms of eBPF ISA support, this series does
not include support for BPF-to-BPF calls and BPF trampolines. Those
features are planned to be added in another patch series.
The BPF_ST | BPF_NOSPEC instruction currently emits nothing. This is
consistent with the behavior if the MIPS interpreter and the existing
eBPF JIT.
Why not build on the existing eBPF JIT?
---------------------------------------
The existing eBPF JIT was originally written for MIPS64. An effort was
made to add MIPS32 support to it in commit 716850ab10 ("MIPS: eBPF:
Initial eBPF support for MIPS32 architecture."). That turned out to
contain a number of flaws, so eBPF support for MIPS32 was disabled in
commit 36366e367e ("MIPS: BPF: Restore MIPS32 cBPF JIT").
Link: https://lore.kernel.org/bpf/5deaa994.1c69fb81.97561.647e@mx.google.com/
The current eBPF JIT for MIPS64 lacks a lot of functionality regarding
ALU32, JMP32 and atomic operations. It also lacks 32-bit CPU support on a
fundamental level, for example 32-bit CPU register mappings and o32 ABI
calling conventions. For optimization purposes, it tracks register usage
through the program control flow in order to do zero-extension and sign-
extension only when necessary, a static analysis of sorts. In my opinion,
having this kind of complexity in JITs, and for which there is not
adequate test coverage, is a problem. Such analysis should be done by the
verifier, if needed at all. Finally, when I run the BPF test suite
test_bpf.ko on the current JIT, there are errors and warnings.
I believe that an eBPF JIT should strive to be correct, complete and
optimized, and in that order. The JIT runs after the verifer has audited
the program and given its approval. If the JIT then emits code that does
something else, it will undermine the eBPF security model. A simple
implementation is easier to get correct than a complex one. Furthermore,
the real performance hit is not an extra CPU instruction here and there,
but when the JIT bails on an unimplemented eBPF instruction and cause the
whole program to fall back to the interpreter. My reasoning here boils
down to the following.
* The JIT should not contain a static analyzer that tracks branches.
* It is acceptable to emit possibly superfluous sign-/zero-extensions for
ALU32 and JMP32 operations on a 64-bit MIPS to guarantee correctness.
* The JIT should handle all eBPF instructions on all MIPS CPUs.
I conclude that the current eBPF MIPS JIT is complex, incomplete and
incorrect. For the reasons stated above, I decided to not use the existing
JIT implementation.
====================
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
This patch removes the old 32-bit cBPF and 64-bit eBPF JIT implementations.
They are replaced by a new eBPF implementation that supports both 32-bit
and 64-bit MIPS CPUs.
Signed-off-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211005165408.2305108-8-johan.almbladh@anyfinetworks.com
This patch enables the new eBPF JITs for 32-bit and 64-bit MIPS. It also
disables the old cBPF JIT to so cBPF programs are converted to use the
new JIT.
Workarounds for R4000 CPU errata are not implemented by the JIT, so the
JIT is disabled if any of those workarounds are configured.
Signed-off-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211005165408.2305108-7-johan.almbladh@anyfinetworks.com
