The test traverses all slab caches using the kmem_cache_iter and save
the data into slab_result array map. And check if current task's
pointer is from "task_struct" slab cache using bpf_get_kmem_cache().
Also compare the result array with /proc/slabinfo if available (when
CONFIG_SLUB_DEBUG is on). Note that many of the fields in the slabinfo
are transient, so it only compares the name and objsize fields.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20241010232505.1339892-4-namhyung@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The bpf_get_kmem_cache() is to get a slab cache information from a
virtual address like virt_to_cache(). If the address is a pointer
to a slab object, it'd return a valid kmem_cache pointer, otherwise
NULL is returned.
It doesn't grab a reference count of the kmem_cache so the caller is
responsible to manage the access. The returned point is marked as
PTR_UNTRUSTED.
The intended use case for now is to symbolize locks in slab objects
from the lock contention tracepoints.
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev> (mm/*)
Acked-by: Vlastimil Babka <vbabka@suse.cz> #mm/slab
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20241010232505.1339892-3-namhyung@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The new "kmem_cache" iterator will traverse the list of slab caches
and call attached BPF programs for each entry. It should check the
argument (ctx.s) if it's NULL before using it.
Now the iteration grabs the slab_mutex only if it traverse the list and
releases the mutex when it runs the BPF program. The kmem_cache entry
is protected by a refcount during the execution.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz> #slab
Link: https://lore.kernel.org/r/20241010232505.1339892-2-namhyung@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The hashmap__for_each_entry[_safe] is accessing 'map' as a pointer.
But it does without parentheses so passing a static hash map with an
ampersand (like '&slab_hash') will cause compiler warnings due
to unmatched types as '->' operator has a higher precedence.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241011170021.1490836-1-namhyung@kernel.org
Add a subprogram to BPF object file that otherwise has no entry BPF
programs to validate that libbpf can still load this correctly.
Until this was fixed, user could expect this very confusing error message:
libbpf: prog 'dangling_subprog': missing BPF prog type, check ELF section name '.text'
libbpf: prog 'dangling_subprog': failed to load: -22
libbpf: failed to load object 'struct_ops_detach'
libbpf: failed to load BPF skeleton 'struct_ops_detach': -22
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20241010211731.4121837-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Libbpf pre-1.0 had a legacy logic of allowing singular non-annotated
(i.e., not having explicit SEC() annotation) function to be treated as
sole entry BPF program (unless there were other explicit entry
programs).
This behavior was dropped during libbpf 1.0 transition period (unless
LIBBPF_STRICT_SEC_NAME flag was unset in libbpf_mode). When 1.0 was
released and all the legacy behavior was removed, the bug slipped
through leaving this legacy behavior around.
Fix this for good, as it actually causes very confusing behavior if BPF
object file only has subprograms, but no entry programs.
Fixes: bd054102a8 ("libbpf: enforce strict libbpf 1.0 behaviors")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20241010211731.4121837-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Daniel T. Lee says:
====================
selftests/bpf: migrate and remove cgroup/tracing related tests
The BPF testing framework has evolved significantly over time. However,
some legacy tests in the samples/bpf directory have not kept up with
these changes. These outdated tests can cause confusion and increase
maintenance efforts.
This patchset focuses on migrating outdated cgroup and tracing-related
tests from samples/bpf to selftests/bpf, ensuring the BPF test suite
remains current and efficient. Tests that are already covered by
selftests/bpf are removed, while those not yet covered are migrated.
This includes cgroup sock create tests for setting socket attributes
and blocking socket creation, as well as the removal of redundant
cgroup and tracing tests that have been replaced by newer tests.
This patchset covers the following cgroup/tracing tests:
- test_overhead: tests the overhead of BPF programs with task_rename,
now covered by selftests and benchmark tests (rename-*). [1]
- test_override_return: tests the return override functionality, now
handled by kprobe_multi_override in selftests.
- test_probe_write_user: tests the probe_write_user functionality,
now replaced by the probe_user test in selftests.
- test_cgrp2_sock: tests cgroup BPF's ability to set sk_bound_dev_if,
mark, and priority during socket creation. Migrated to selftests as
'sock_create' since no existing tests fully cover this.
- test_cgrp2_sock2: tests blocking socket creation for specific types
(AF_INET{6}, SOCK_DGRAM, IPPROTO_ICMP{V6}). Migrated to selftests
in 'sock_create' test for coverage.
- test_current_task_under_cgroup: tests bpf_current_task_under_cgroup()
to check if a task belongs to a cgroup. Already covered by
task_under_cgroup at selftest and other cgroup ID tests.
- test_cgrp2_tc: tests bpf_skb_under_cgroup() to filter packets based
on cgroup. This behavior is now validated by cgroup_skb_sk_lookup,
which uses bpf_skb_cgroup_id, making this test redundant.
[1]: https://patchwork.kernel.org/cover/13759916
---
Changes in v2:
- commit message fix
Changes in v3:
- Makefile fix
====================
Link: https://lore.kernel.org/r/20241011044847.51584-1-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The samples/bpf has become outdated and often does not follow up with
the latest. This commit removes obsolete tracing-related tests.
Specifically, 'test_overhead' is duplicate with selftests (and bench),
and 'test_override_return', 'test_probe_write_user' tests are obsolete
since they have been replaced by kprobe_multi_override and probe_user
from selftests respectively.
The following files are removed:
- test_overhead: tests the overhead of BPF programs with task_rename,
now covered by selftests and benchmark tests (rename-*). [1]
- test_override_return: tests the return override functionality, now
handled by kprobe_multi_override in selftests.
- test_probe_write_user: tests the probe_write_user functionality,
now replaced by the probe_user test in selftests.
This cleanup will help to streamline the testing framework by removing
redundant tests.
[1]: https://patchwork.kernel.org/cover/13759916
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20241011044847.51584-5-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch removes the obsolete cgroup related tests. These tests are
now redundant because their functionality is already covered by more
modern and comprehensive tests under selftests/bpf.
The following files are removed:
- test_current_task_under_cgroup: tests bpf_current_task_under_cgroup()
to check if a task belongs to a cgroup. Already covered by
task_under_cgroup at selftest and other cgroup ID tests.
- test_cgrp2_tc: tests bpf_skb_under_cgroup() to filter packets based
on cgroup. This behavior is now validated by cgroup_skb_sk_lookup,
which uses bpf_skb_cgroup_id, making this test redundant.
By removing these outdated tests, this patch helps streamline and
modernize the test suite, avoiding duplication of test coverage.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20241011044847.51584-4-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch continues the migration and removal process for cgroup
sock_create tests to selftests.
The test being migrated verifies the ability of cgroup BPF to block the
creation of specific types of sockets using a verdict. Specifically, the
test denies socket creation when the socket is of type AF_INET{6},
SOCK_DGRAM, and IPPROTO_ICMP{V6}. If the requested socket type matches
these attributes, the cgroup BPF verdict blocks the socket creation.
As with the previous commit, this test currently lacks coverage in
selftests, so this patch migrates the functionality into the sock_create
tests under selftests. This migration ensures that the socket creation
blocking behavior with cgroup bpf program is properly tested within the
selftest framework.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20241011044847.51584-3-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch migrates the old test for cgroup BPF that sets
sk_bound_dev_if, mark, and priority when AF_INET{6} sockets are created.
The most closely related tests under selftests are 'test_sock' and
'sockopt'. However, these existing tests serve different purposes.
'test_sock' focuses mainly on verifying the socket binding process,
while 'sockopt' concentrates on testing the behavior of getsockopt and
setsockopt operations for various socket options.
Neither of these existing tests directly covers the ability of cgroup
BPF to set socket attributes such as sk_bound_dev_if, mark, and priority
during socket creation. To address this gap, this patch introduces a
migration of the old cgroup socket attribute test, now included as the
'sock_create' test in selftests/bpf. This ensures that the ability to
configure these attributes during socket creation is properly tested.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20241011044847.51584-2-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The documentation says CONFIG_FUNCTION_ERROR_INJECTION is supported only
on x86. This was presumably true at the time of writing, but it's now
supported on many other architectures too. Drop this statement, since
it's not correct anymore and it fits better in other documentation
anyway.
Signed-off-by: Martin Kelly <martin.kelly@crowdstrike.com>
Link: https://lore.kernel.org/r/20241010193301.995909-1-martin.kelly@crowdstrike.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
sym_is_subprog() is incorrectly rejecting relocations against *weak*
global subprogs. Fix that by realizing that STB_WEAK is also a global
function.
While it seems like verifier doesn't support taking an address of
non-static subprog right now, it's still best to fix support for it on
libbpf side, otherwise users will get a very confusing error during BPF
skeleton generation or static linking due to misinterpreted relocation:
libbpf: prog 'handle_tp': bad map relo against 'foo' in section '.text'
Error: failed to open BPF object file: Relocation failed
It's clearly not a map relocation, but is treated and reported as such
without this fix.
Fixes: 53eddb5e04 ("libbpf: Support subprog address relocation")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20241009011554.880168-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
test_progs uses glibc specific functions backtrace() and
backtrace_symbols_fd() to print backtrace in case of SIGSEGV.
Recent commit (see fixes) updated test_progs.c to define stub versions
of the same functions with attriubte "weak" in order to allow linking
test_progs against musl libc. Unfortunately this broke the backtrace
handling for glibc builds.
As it turns out, glibc defines backtrace() and backtrace_symbols_fd()
as weak:
$ llvm-readelf --symbols /lib64/libc.so.6 \
| grep -P '( backtrace_symbols_fd| backtrace)$'
4910: 0000000000126b40 161 FUNC WEAK DEFAULT 16 backtrace
6843: 0000000000126f90 852 FUNC WEAK DEFAULT 16 backtrace_symbols_fd
So does test_progs:
$ llvm-readelf --symbols test_progs \
| grep -P '( backtrace_symbols_fd| backtrace)$'
2891: 00000000006ad190 15 FUNC WEAK DEFAULT 13 backtrace
11215: 00000000006ad1a0 41 FUNC WEAK DEFAULT 13 backtrace_symbols_fd
In such situation dynamic linker is not obliged to favour glibc
implementation over the one defined in test_progs.
Compiling with the following simple modification to test_progs.c
demonstrates the issue:
$ git diff
...
\--- a/tools/testing/selftests/bpf/test_progs.c
\+++ b/tools/testing/selftests/bpf/test_progs.c
\@@ -1817,6 +1817,7 @@ int main(int argc, char **argv)
if (err)
return err;
+ *(int *)0xdeadbeef = 42;
err = cd_flavor_subdir(argv[0]);
if (err)
return err;
$ ./test_progs
[0]: Caught signal #11!
Stack trace:
<backtrace not supported>
Segmentation fault (core dumped)
Resolve this by hiding stub definitions behind __GLIBC__ macro check
instead of using "weak" attribute.
Fixes: c9a83e76b5 ("selftests/bpf: Fix compile if backtrace support missing in libc")
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Tony Ambardar <tony.ambardar@gmail.com>
Reviewed-by: Tony Ambardar <tony.ambardar@gmail.com>
Acked-by: Daniel Xu <dxu@dxuuu.xyz>
Link: https://lore.kernel.org/bpf/20241003210307.3847907-1-eddyz87@gmail.com
During the xdp_adjust_tail test, probabilistic failure occurs and SKB package
is discarded by the kernel. After checking the issues by tracking SKB package,
it is identified that they were caused by checksum errors. Refer to checksum
of the arch/arm64/include/asm/checksum.h for fixing.
v2: Based on Alexei Starovoitov's suggestions, it is necessary to keep the code
implementation consistent.
Fixes: c6ffd1ff78 (bpf: add bpf_xdp_adjust_tail sample prog)
Signed-off-by: Yuan Chen <chenyuan@kylinos.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240930024115.52841-1-chenyuan_fl@163.com
The prog_tests programs do not include the per-arch tools include
path, e.g. tools/arch/riscv/include. Some architectures depend those
files to build properly.
Include tools/arch/$(SUBARCH)/include in the selftests bpf build.
Fixes: 6d74d178fe ("tools: Add riscv barrier implementation")
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240927131355.350918-2-bjorn@kernel.org
Production BPF programs are increasing in number of instructions and states
to the point, where optimising verification process for them is necessary
to avoid running into instruction limit. Authors of those BPF programs
need to analyze verifier output, for example, collecting the most
frequent source code lines to understand which part of the program has
the biggest verification cost.
This patch introduces `--top-src-lines` flag in veristat.
`--top-src-lines=N` makes veristat output N the most popular sorce code
lines, parsed from verification log.
An example of output:
```
sudo ./veristat --top-src-lines=2 bpf_flow.bpf.o
Processing 'bpf_flow.bpf.o'...
Top source lines (_dissect):
4: (bpf_helpers.h:161) asm volatile("r1 = %[ctx]\n\t"
4: (bpf_flow.c:155) if (iph && iph->ihl == 5 &&
...
```
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240930231522.58650-1-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Eduard Zingerman says:
====================
'bpf_fastcall' attribute in vmlinux.h and bpf_helper_defs.h
The goal of this patch-set is to reflect attribute bpf_fastcall
for supported helpers and kfuncs in generated header files.
For helpers this requires a tweak for scripts/bpf_doc.py and an update
to uapi/linux/bpf.h doc-comment.
For kfuncs this requires:
- introduction of a new KF_FASTCALL flag;
- modification to pahole to read kfunc flags and generate
DECL_TAG "bpf_fastcall" for marked kfuncs;
- modification to bpftool to scan for DECL_TAG "bpf_fastcall"
presence.
In both cases the following helper macro is defined in the generated
header:
#ifndef __bpf_fastcall
#if __has_attribute(bpf_fastcall)
#define __bpf_fastcall __attribute__((bpf_fastcall))
#else
#define __bpf_fastcall
#endif
#endif
And is used to mark appropriate function prototypes. More information
about bpf_fastcall attribute could be found in [1] and [2].
Modifications to pahole are submitted separately.
[1] LLVM source tree commit:
64e464349bfc ("[BPF] introduce __attribute__((bpf_fastcall))")
[2] Linux kernel tree commit (note: feature was renamed from
no_caller_saved_registers to bpf_fastcall after this commit):
52839f31ce ("Merge branch 'no_caller_saved_registers-attribute-for-helper-calls'")
====================
Link: https://lore.kernel.org/r/20240916091712.2929279-1-eddyz87@gmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Since [1] kernel supports __bpf_fastcall attribute for helper function
bpf_get_smp_processor_id(). Update uapi definition for this helper in
order to have this attribute in the generated bpf_helper_defs.h
[1] commit 91b7fbf393 ("bpf, x86, riscv, arm: no_caller_saved_registers for bpf_get_smp_processor_id()")
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240916091712.2929279-3-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Allow a new optional 'Attributes' section to be specified for helper
functions description, e.g.:
* u32 bpf_get_smp_processor_id(void)
* ...
* Return
* ...
* Attributes
* __bpf_fastcall
*
Generated header for the example above:
#ifndef __bpf_fastcall
#if __has_attribute(__bpf_fastcall)
#define __bpf_fastcall __attribute__((bpf_fastcall))
#else
#define __bpf_fastcall
#endif
#endif
...
__bpf_fastcall
static __u32 (* const bpf_get_smp_processor_id)(void) = (void *) 8;
The following rules apply:
- when present, section must follow 'Return' section;
- attribute names are specified on the line following 'Attribute'
keyword;
- attribute names are separated by spaces;
- section ends with an "empty" line (" *\n").
Valid attribute names are recorded in the ATTRS map.
ATTRS maps shortcut attribute name to correct C syntax.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240916091712.2929279-2-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tony Ambardar says:
====================
libbpf, selftests/bpf: Support cross-endian usage
Hello all,
This patch series targets a long-standing BPF usability issue - the lack
of general cross-compilation support - by enabling cross-endian usage of
libbpf and bpftool, as well as supporting cross-endian build targets for
selftests/bpf.
Benefits include improved BPF development and testing for embedded systems
based on e.g. big-endian MIPS, more build options e.g for s390x systems,
and better accessibility to the very latest test tools e.g. 'test_progs'.
The series touches many functional areas: BTF.ext handling; object access,
introspection, and linking; generation of normal and "light" skeletons.
Initial development and testing used mips64, since this arch makes
switching the build byte-order trivial and is thus very handy for A/B
testing. However, it lacks some key features (bpf2bpf call, kfuncs, etc)
making for poor selftests/bpf coverage.
Final testing takes the kernel and selftests/bpf cross-built from x86_64
to s390x, and runs the result under QEMU/s390x. That same configuration
could also be used on kernel-patches/bpf CI for regression testing endian
support or perhaps load-sharing s390x builds across x86_64 systems.
This thread includes some background regarding testing on QEMU/s390x and
the generally favourable results:
https://lore.kernel.org/bpf/ZsEcsaa3juxxQBUf@kodidev-ubuntu/
Earlier versions and related discussion of the series are here:
v1: https://lore.kernel.org/bpf/cover.1724216108.git.tony.ambardar@gmail.com/
v2: https://lore.kernel.org/bpf/cover.1724313164.git.tony.ambardar@gmail.com/
v3: https://lore.kernel.org/bpf/cover.1724843049.git.tony.ambardar@gmail.com/
v4: https://lore.kernel.org/bpf/cover.1724976539.git.tony.ambardar@gmail.com/
v5: https://lore.kernel.org/bpf/cover.1725347944.git.tony.ambardar@gmail.com/
Feedback and suggestions are welcome!
Best regards,
Tony
Changelog:
---------
v5 -> v6: (comments from Andrii, Alexei, Eduard)
- clarify info_blob_bswap() by making it explicitly conditional on
non-native target endianness, and merge a pair of related debug
statements
- reformat debug statement in bpf_object_bswap_progs() on single line
- update existing info setup functions to validate and parse info
section metadata prior to any byte-swapping, and drop earlier added
validation checks
- rework cross-endian BTF.ext handling by using callback functions to
byte-swap different types of info records, but after initial parsing
- fix a bug always outputting BTF.ext raw data in native endianness
- include v5 "Acked-by:" from Alexei, Yonghong
v4 -> v5: (feedback from Andrii and Eduard)
- add separate functions to byte-swap info metadata and records, and
ensure ordering so record bswaps occur when metadata is native endian
- use new and existing macros to iterate through info sections/records,
and check embedded record sizes match that of info structs used
- drop use of <cough> evil callbacks
- move setting swapped_endian flag to after byte-swapping functions are
called during initialization, allowing funcs to infer endianness and
drop a 'bool native' call parameter
- simplify byte-swapping macro used to generate light skeleton, and use
internal lib funcs to swap info records instead of assuming all __u32
- change info bswap library funcs to void return
- rework/consolidate new debug statements to reduce their number
- remove some unneeded handling of impossible errors, and drop a safety
check already handled elsewhere
- add and clarify some comments
v3 -> v4:
- fix a use-after-free ELF data-handling error causing rare CI failures
- move bswap functions for func/line/core-relo records to internal header
- use bswap functions also for info blobs in light skeleton
v2 -> v3: (feedback from Andrii)
- improve some log and commit message formatting
- restructure BTF.ext endianness safety checks and byte-swapping
- use BTF.ext info record definitions for swapping, require BTF v1
- follow BTF API implementation more closely for BTF.ext
- explicitly reject loading non-native endianness program into kernel
- simplify linker output byte-order setting
- drop redundant safety checks during linking
- simplify endianness macro and improve blob setup code for light skel
- no unexpected test failures after cross-compiling x86_64 -> s390x
v1 -> v2:
- fixed a light skeleton bug causing test_progs 'map_ptr' failure
- simplified some BTF.ext related endianness logic
- remove an 'inline' usage related to CI checkpatch failure
- improve some formatting noted by checkpatch warnings
- unexpected 'test_progs' failures drop 3 -> 2 (x86_64 to s390x cross)
====================
Link: https://lore.kernel.org/r/cover.1726475448.git.tony.ambardar@gmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When building selftests, the following was seen:
uprobe_multi.c: In function ‘trigger_uprobe’:
uprobe_multi.c:108:40: error: ‘MADV_PAGEOUT’ undeclared (first use in this function)
108 | madvise(addr, page_sz, MADV_PAGEOUT);
| ^~~~~~~~~~~~
uprobe_multi.c:108:40: note: each undeclared identifier is reported only once for each function it appears in
make: *** [Makefile:850: bpf-next/tools/testing/selftests/bpf/uprobe_multi] Error 1
...even with updated UAPI headers. It seems the above value is
defined in UAPI <linux/mman.h> but including that file triggers
other redefinition errors. Simplest solution is to add a
guarded definition, as was done for MADV_POPULATE_READ.
Fixes: 3c217a1820 ("selftests/bpf: add build ID tests")
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20240926144948.172090-1-alan.maguire@oracle.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Track target endianness in 'struct bpf_gen' and process in-memory data in
native byte-order, but on finalization convert the embedded loader BPF
insns to target endianness.
The light skeleton also includes a target-accessed data blob which is
heterogeneous and thus difficult to convert to target byte-order on
finalization. Add support functions to convert data to target endianness
as it is added to the blob.
Also add additional debug logging for data blob structure details and
skeleton loading.
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/569562e1d5bf1cce80a1f1a3882461ee2da1ffd5.1726475448.git.tony.ambardar@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Allow static linking object files of either endianness, checking that input
files have consistent byte-order, and setting output endianness from input.
Linking requires in-memory processing of programs, relocations, sections,
etc. in native endianness, and output conversion to target byte-order. This
is enabled by built-in ELF translation and recent BTF/BTF.ext endianness
functions. Further add local functions for swapping byte-order of sections
containing BPF insns.
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/b47ca686d02664843fc99b96262fe3259650bc43.1726475448.git.tony.ambardar@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Support for handling BTF data of either endianness was added in [1], but
did not include BTF.ext data for lack of use cases. Later, support for
static linking [2] provided a use case, but this feature and later ones
were restricted to native-endian usage.
Add support for BTF.ext handling in either endianness. Convert BTF.ext data
to native endianness when read into memory for further processing, and
support raw data access that restores the original byte-order for output.
Add internal header functions for byte-swapping func, line, and core info
records.
Add new API functions btf_ext__endianness() and btf_ext__set_endianness()
for query and setting byte-order, as already exist for BTF data.
[1] 3289959b97 ("libbpf: Support BTF loading and raw data output in both endianness")
[2] 8fd27bf69b ("libbpf: Add BPF static linker BTF and BTF.ext support")
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/133407ab20e0dd5c07cab2a6fa7879dee1ffa4bc.1726475448.git.tony.ambardar@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
danobi/vmtest is going to migrate from using 9p to using virtio_fs to
mount the local rootfs: https://github.com/danobi/vmtest/pull/88
BPF CI uses danobi/vmtest to run bpf selftests and will need to support
VIRTIO_FS.
This change enables new kconfigs to be able to support the upcoming
danobi/vmtest.
Tested by building a new kernel with those config and confirming it
would successfully run with 9p (currently what is used by vmtest), and
with virtio_fs (using a local build of vmtest).
$ vmtest -k arch/x86/boot/bzImage "findmnt /"
=> bzImage
===> Booting
===> Setting up VM
===> Running command
TARGET SOURCE FSTYPE OPTIONS
/ /dev/root 9p rw,relatime,cache=5,access=client,msize=512000,trans=virtio
$ /home/chantra/local/danobi-vmtest/target/debug/vmtest -k arch/x86/boot/bzImage "findmnt /"
=> bzImage
===> Initializing host environment
===> Booting
===> Setting up VM
===> Running command
TARGET SOURCE FSTYPE OPTIONS
/ rootfs virtiofs rw,relatime
Changes in v2:
* Sorted configs alphabetically
Signed-off-by: Manu Bretelle <chantr4@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Daniel Xu <dxu@dxuuu.xyz>
Link: https://lore.kernel.org/bpf/20240925002210.501266-1-chantr4@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Referenced commit broke the logic of resetting expected_attach_type to
zero for allowed program types if kernel doesn't yet support such field.
We do need to overwrite and preserve expected_attach_type for
multi-uprobe though, but that can be done explicitly in
libbpf_prepare_prog_load().
Fixes: 5902da6d8a ("libbpf: Add uprobe multi link support to bpf_program__attach_usdt")
Suggested-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Tao Chen <chen.dylane@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240925153012.212866-1-chen.dylane@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reduce log level of BTF loading error to INFO if BTF is not required.
Andrii says:
Nowadays the expectation is that the BPF program will have a valid
.BTF section, so even though .BTF is "optional", I think it's fine
to emit a warning for that case (any reasonably recent Clang will
produce valid BTF).
Ihor's patch is fixing the situation with an outdated host kernel
that doesn't understand BTF. libbpf will try to "upload" the
program's BTF, but if that fails and the BPF object doesn't use
any features that require having BTF uploaded, then it's just an
information message to the user, but otherwise can be ignored.
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Ihor Solodrai <ihor.solodrai@pm.me>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
struct btf_kind_operations are not modified in BTF.
Constifying this structures moves some data to a read-only section,
so increase overall security, especially when the structure holds
some function pointers.
On a x86_64, with allmodconfig:
Before:
======
text data bss dec hex filename
184320 7091 548 191959 2edd7 kernel/bpf/btf.o
After:
=====
text data bss dec hex filename
184896 6515 548 191959 2edd7 kernel/bpf/btf.o
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/9192ab72b2e9c66aefd6520f359a20297186327f.1726417289.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
