Daniel Borkmann says:
====================
pull-request: bpf-next 2024-03-25
We've added 38 non-merge commits during the last 13 day(s) which contain
a total of 50 files changed, 867 insertions(+), 274 deletions(-).
The main changes are:
1) Add the ability to specify and retrieve BPF cookie also for raw
tracepoint programs in order to ease migration from classic to raw
tracepoints, from Andrii Nakryiko.
2) Allow the use of bpf_get_{ns_,}current_pid_tgid() helper for all
program types and add additional BPF selftests, from Yonghong Song.
3) Several improvements to bpftool and its build, for example, enabling
libbpf logs when loading pid_iter in debug mode, from Quentin Monnet.
4) Check the return code of all BPF-related set_memory_*() functions during
load and bail out in case they fail, from Christophe Leroy.
5) Avoid a goto in regs_refine_cond_op() such that the verifier can
be better integrated into Agni tool which doesn't support backedges
yet, from Harishankar Vishwanathan.
6) Add a small BPF trie perf improvement by always inlining
longest_prefix_match, from Jesper Dangaard Brouer.
7) Small BPF selftest refactor in bpf_tcp_ca.c to utilize start_server()
helper instead of open-coding it, from Geliang Tang.
8) Improve test_tc_tunnel.sh BPF selftest to prevent client connect
before the server bind, from Alessandro Carminati.
9) Fix BPF selftest benchmark for older glibc and use syscall(SYS_gettid)
instead of gettid(), from Alan Maguire.
10) Implement a backward-compatible method for struct_ops types with
additional fields which are not present in older kernels,
from Kui-Feng Lee.
11) Add a small helper to check if an instruction is addr_space_cast
from as(0) to as(1) and utilize it in x86-64 JIT, from Puranjay Mohan.
12) Small cleanup to remove unnecessary error check in
bpf_struct_ops_map_update_elem, from Martin KaFai Lau.
13) Improvements to libbpf fd validity checks for BPF map/programs,
from Mykyta Yatsenko.
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (38 commits)
selftests/bpf: Fix flaky test btf_map_in_map/lookup_update
bpf: implement insn_is_cast_user() helper for JITs
bpf: Avoid get_kernel_nofault() to fetch kprobe entry IP
selftests/bpf: Use start_server in bpf_tcp_ca
bpf: Sync uapi bpf.h to tools directory
libbpf: Add new sec_def "sk_skb/verdict"
selftests/bpf: Mark uprobe trigger functions with nocf_check attribute
selftests/bpf: Use syscall(SYS_gettid) instead of gettid() wrapper in bench
bpf-next: Avoid goto in regs_refine_cond_op()
bpftool: Clean up HOST_CFLAGS, HOST_LDFLAGS for bootstrap bpftool
selftests/bpf: scale benchmark counting by using per-CPU counters
bpftool: Remove unnecessary source files from bootstrap version
bpftool: Enable libbpf logs when loading pid_iter in debug mode
selftests/bpf: add raw_tp/tp_btf BPF cookie subtests
libbpf: add support for BPF cookie for raw_tp/tp_btf programs
bpf: support BPF cookie in raw tracepoint (raw_tp, tp_btf) programs
bpf: pass whole link instead of prog when triggering raw tracepoint
bpf: flatten bpf_probe_register call chain
selftests/bpf: Prevent client connect before server bind in test_tc_tunnel.sh
selftests/bpf: Add a sk_msg prog bpf_get_ns_current_pid_tgid() test
...
====================
Link: https://lore.kernel.org/r/20240325233940.7154-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Daniel Borkmann says:
====================
pull-request: bpf 2024-03-25
The following pull-request contains BPF updates for your *net* tree.
We've added 17 non-merge commits during the last 12 day(s) which contain
a total of 19 files changed, 184 insertions(+), 61 deletions(-).
The main changes are:
1) Fix an arm64 BPF JIT bug in BPF_LDX_MEMSX implementation's offset handling
found via test_bpf module, from Puranjay Mohan.
2) Various fixups to the BPF arena code in particular in the BPF verifier and
around BPF selftests to match latest corresponding LLVM implementation,
from Puranjay Mohan and Alexei Starovoitov.
3) Fix xsk to not assume that metadata is always requested in TX completion,
from Stanislav Fomichev.
4) Fix riscv BPF JIT's kfunc parameter incompatibility between BPF and the riscv
ABI which requires sign-extension on int/uint, from Pu Lehui.
5) Fix s390x BPF JIT's bpf_plt pointer arithmetic which triggered a crash when
testing struct_ops, from Ilya Leoshkevich.
6) Fix libbpf's arena mmap handling which had incorrect u64-to-pointer cast on
32-bit architectures, from Andrii Nakryiko.
7) Fix libbpf to define MFD_CLOEXEC when not available, from Arnaldo Carvalho de Melo.
8) Fix arm64 BPF JIT implementation for 32bit unconditional bswap which
resulted in an incorrect swap as indicated by test_bpf, from Artem Savkov.
9) Fix BPF man page build script to use silent mode, from Hangbin Liu.
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
riscv, bpf: Fix kfunc parameters incompatibility between bpf and riscv abi
bpf: verifier: reject addr_space_cast insn without arena
selftests/bpf: verifier_arena: fix mmap address for arm64
bpf: verifier: fix addr_space_cast from as(1) to as(0)
libbpf: Define MFD_CLOEXEC if not available
arm64: bpf: fix 32bit unconditional bswap
bpf, arm64: fix bug in BPF_LDX_MEMSX
libbpf: fix u64-to-pointer cast on 32-bit arches
s390/bpf: Fix bpf_plt pointer arithmetic
xsk: Don't assume metadata is always requested in TX completion
selftests/bpf: Add arena test case for 4Gbyte corner case
selftests/bpf: Remove hard coded PAGE_SIZE macro.
libbpf, selftests/bpf: Adjust libbpf, bpftool, selftests to match LLVM
bpf: Clarify bpf_arena comments.
MAINTAINERS: Update email address for Quentin Monnet
scripts/bpf_doc: Use silent mode when exec make cmd
bpf: Temporarily disable atomic operations in BPF arena
====================
Link: https://lore.kernel.org/r/20240325213520.26688-1-daniel@iogearbox.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Pull Kbuild updates from Masahiro Yamada:
- Generate a list of built DTB files (arch/*/boot/dts/dtbs-list)
- Use more threads when building Debian packages in parallel
- Fix warnings shown during the RPM kernel package uninstallation
- Change OBJECT_FILES_NON_STANDARD_*.o etc. to take a relative path to
Makefile
- Support GCC's -fmin-function-alignment flag
- Fix a null pointer dereference bug in modpost
- Add the DTB support to the RPM package
- Various fixes and cleanups in Kconfig
* tag 'kbuild-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (67 commits)
kconfig: tests: test dependency after shuffling choices
kconfig: tests: add a test for randconfig with dependent choices
kconfig: tests: support KCONFIG_SEED for the randconfig runner
kbuild: rpm-pkg: add dtb files in kernel rpm
kconfig: remove unneeded menu_is_visible() call in conf_write_defconfig()
kconfig: check prompt for choice while parsing
kconfig: lxdialog: remove unused dialog colors
kconfig: lxdialog: fix button color for blackbg theme
modpost: fix null pointer dereference
kbuild: remove GCC's default -Wpacked-bitfield-compat flag
kbuild: unexport abs_srctree and abs_objtree
kbuild: Move -Wenum-{compare-conditional,enum-conversion} into W=1
kconfig: remove named choice support
kconfig: use linked list in get_symbol_str() to iterate over menus
kconfig: link menus to a symbol
kbuild: fix inconsistent indentation in top Makefile
kbuild: Use -fmin-function-alignment when available
alpha: merge two entries for CONFIG_ALPHA_GAMMA
alpha: merge two entries for CONFIG_ALPHA_EV4
kbuild: change DTC_FLAGS_<basetarget>.o to take the path relative to $(obj)
...
Since its going directly to the syscall to avoid not having
memfd_create() available in some systems, do the same for its
MFD_CLOEXEC flags, defining it if not available.
This fixes the build in those systems, noticed while building perf on a
set of build containers.
Fixes: 9fa5e1a180 ("libbpf: Call memfd_create() syscall directly")
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/ZfxZ9nCyKvwmpKkE@x1
It's been reported that (void *)map->map_extra is causing compilation
warnings on 32-bit architectures. It's easy enough to fix this by
casting to long first.
Fixes: 79ff13e991 ("libbpf: Add support for bpf_arena.")
Reported-by: Ryan Eatmon <reatmon@ti.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Message-ID: <20240319215143.1279312-1-andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
libbpf creates bpf_program/bpf_map structs for each program/map that
user defines, but it allows to disable creating/loading those objects in
kernel, in that case they won't have associated file descriptor
(fd < 0). Such functionality is used for backward compatibility
with some older kernels.
Nothing prevents users from passing these maps or programs with no
kernel counterpart to libbpf APIs. This change introduces explicit
checks for kernel objects existence, aiming to improve visibility of
those edge cases and provide meaningful warnings to users.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240318131808.95959-1-yatsenko@meta.com
The selftests use
to tell LLVM about special pointers. For LLVM there is nothing "arena"
about them. They are simply pointers in a different address space.
Hence LLVM diff https://github.com/llvm/llvm-project/pull/85161 renamed:
. macro __BPF_FEATURE_ARENA_CAST -> __BPF_FEATURE_ADDR_SPACE_CAST
. global variables in __attribute__((address_space(N))) are now
placed in section named ".addr_space.N" instead of ".arena.N".
Adjust libbpf, bpftool, and selftests to match LLVM.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20240315021834.62988-3-alexei.starovoitov@gmail.com
Pull perf tools updates from Namhyung Kim:
"perf stat:
- Support new 'cluster' aggregation mode for shared resources
depending on the hardware configuration:
$ sudo perf stat -a --per-cluster -e cycles,instructions sleep 1
Performance counter stats for 'system wide':
S0-D0-CLS0 2 85,051,822 cycles
S0-D0-CLS0 2 73,909,908 instructions # 0.87 insn per cycle
S0-D0-CLS2 2 93,365,918 cycles
S0-D0-CLS2 2 83,006,158 instructions # 0.89 insn per cycle
S0-D0-CLS4 2 104,157,523 cycles
S0-D0-CLS4 2 53,234,396 instructions # 0.51 insn per cycle
S0-D0-CLS6 2 65,891,079 cycles
S0-D0-CLS6 2 41,478,273 instructions # 0.63 insn per cycle
1.002407989 seconds time elapsed
- Various fixes and cleanups for event metrics including NaN handling
perf script:
- Use libcapstone if available to disassemble the instructions. This
enables 'perf script -F disasm' and 'perf script --insn-trace=disasm'
(for Intel-PT):
$ perf script -F event,ip,disasm
cycles:P: ffffffffa988d428 wrmsr
cycles:P: ffffffffa9839d25 movq %rax, %r14
cycles:P: ffffffffa9cdcaf0 endbr64
cycles:P: ffffffffa988d428 wrmsr
cycles:P: ffffffffa988d428 wrmsr
cycles:P: ffffffffaa401f86 iretq
cycles:P: ffffffffa99c4de5 movq 0x30(%rcx), %r8
cycles:P: ffffffffa988d428 wrmsr
cycles:P: ffffffffaa401f86 iretq
cycles:P: ffffffffa9907983 movl 0x68(%rbx), %eax
cycles:P: ffffffffa988d428 wrmsr
- Expose sample ID / stream ID to python scripts
perf test:
- Add more perf test cases from Redhat internal test suites. This
time it adds the base infra and a few perf probe tests. More to
come. :)
- Add 'perf test -p' for parallel execution and fix some issues found
by the parallel test
- Support symbol test to print symbols in given (active) module:
$ perf test -F -v Symbols --dso /lib/modules/$(uname -r)/kernel/fs/ext4/ext4.ko
--- start ---
Testing /lib/modules/6.5.13-1rodete2-amd64/kernel/fs/ext4/ext4.ko
Overlapping symbols:
7a990-7a9a0 l __pfx_ext4_exit_fs
7a990-7a9a0 g __pfx_cleanup_module
Overlapping symbols:
7a9a0-7aa1c l ext4_exit_fs
7a9a0-7aa1c g cleanup_module
...
JSON metric updates:
- A new round of Intel metric updates
- Support Power11 PVR (compatible to Power10)
- Fix cache latency events on Zen 4 to set SliceId properly
Internal:
- Fix reference counting for 'map' data structure, tireless work from
Ian!
- More memory optimization for struct thread and annotate histogram.
Now, 'perf report' (TUI) and 'perf annotate' should be much
lighter-weight in terms of memory footprint
- Support cross-arch perf register access. Clean up the build
configuration so that it can detect arch-register support at
runtime. This can allow to parse register data in sample which was
recorded in a different arch
Others:
- Sync task state in 'perf sched' to kernel using trace event fields.
The task states have been changed so tools cannot assume a fixed
encoding
- Clean up 'perf mem' to generalize the arch-specific events
- Add support for local and global variables to data type profiling.
This would increase the success rate of type resolution with DWARF
- Add short option -H for --hierarchy in 'perf report' and 'perf top'"
* tag 'perf-tools-for-v6.9-2024-03-13' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (154 commits)
perf annotate: Add comments in the data structures
perf annotate: Remove sym_hist.addr[] array
perf annotate: Calculate instruction overhead using hashmap
perf annotate: Add a hashmap for symbol histogram
perf threads: Reduce table size from 256 to 8
perf threads: Switch from rbtree to hashmap
perf threads: Move threads to its own files
perf machine: Move machine's threads into its own abstraction
perf machine: Move fprintf to for_each loop and a callback
perf trace: Ignore thread hashing in summary
perf report: Sort child tasks by tid
perf vendor events amd: Fix Zen 4 cache latency events
perf version: Display availability of OpenCSD support
perf vendor events intel: Add umasks/occ_sel to PCU events.
perf map: Fix map reference count issues
libperf evlist: Avoid out-of-bounds access
perf lock contention: Account contending locks too
perf metrics: Fix segv for metrics with no events
perf metrics: Fix metric matching
perf pmu: Fix a potential memory leak in perf_pmu__lookup()
...
Accept additional fields of a struct_ops type with all zero values even if
these fields are not in the corresponding type in the kernel. This provides
a way to be backward compatible. User space programs can use the same map
on a machine running an old kernel by clearing fields that do not exist in
the kernel.
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240313214139.685112-2-thinker.li@gmail.com
In bpf_objec_load_prog(), there's no guarantee that obj->btf is non-NULL
when passing it to btf__fd(), and this function does not perform any
check before dereferencing its argument (as bpf_object__btf_fd() used to
do). As a consequence, we get segmentation fault errors in bpftool (for
example) when trying to load programs that come without BTF information.
v2: Keep btf__fd() in the fix instead of reverting to bpf_object__btf_fd().
Fixes: df7c3f7d3a ("libbpf: make uniform use of btf__fd() accessor inside libbpf")
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Quentin Monnet <qmo@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240314150438.232462-1-qmo@kernel.org
LLVM automatically places __arena variables into ".arena.1" ELF section.
In order to use such global variables bpf program must include definition
of arena map in ".maps" section, like:
struct {
__uint(type, BPF_MAP_TYPE_ARENA);
__uint(map_flags, BPF_F_MMAPABLE);
__uint(max_entries, 1000); /* number of pages */
__ulong(map_extra, 2ull << 44); /* start of mmap() region */
} arena SEC(".maps");
libbpf recognizes both uses of arena and creates single `struct bpf_map *`
instance in libbpf APIs.
".arena.1" ELF section data is used as initial data image, which is exposed
through skeleton and bpf_map__initial_value() to the user, if they need to tune
it before the load phase. During load phase, this initial image is copied over
into mmap()'ed region corresponding to arena, and discarded.
Few small checks here and there had to be added to make sure this
approach works with bpf_map__initial_value(), mostly due to hard-coded
assumption that map->mmaped is set up with mmap() syscall and should be
munmap()'ed. For arena, .arena.1 can be (much) smaller than maximum
arena size, so this smaller data size has to be tracked separately.
Given it is enforced that there is only one arena for entire bpf_object
instance, we just keep it in a separate field. This can be generalized
if necessary later.
All global variables from ".arena.1" section are accessible from user space
via skel->arena->name_of_var.
For bss/data/rodata the skeleton/libbpf perform the following sequence:
1. addr = mmap(MAP_ANONYMOUS)
2. user space optionally modifies global vars
3. map_fd = bpf_create_map()
4. bpf_update_map_elem(map_fd, addr) // to store values into the kernel
5. mmap(addr, MAP_FIXED, map_fd)
after step 5 user spaces see the values it wrote at step 2 at the same addresses
arena doesn't support update_map_elem. Hence skeleton/libbpf do:
1. addr = malloc(sizeof SEC ".arena.1")
2. user space optionally modifies global vars
3. map_fd = bpf_create_map(MAP_TYPE_ARENA)
4. real_addr = mmap(map->map_extra, MAP_SHARED | MAP_FIXED, map_fd)
5. memcpy(real_addr, addr) // this will fault-in and allocate pages
At the end look and feel of global data vs __arena global data is the same from
bpf prog pov.
Another complication is:
struct {
__uint(type, BPF_MAP_TYPE_ARENA);
} arena SEC(".maps");
int __arena foo;
int bar;
ptr1 = &foo; // relocation against ".arena.1" section
ptr2 = &arena; // relocation against ".maps" section
ptr3 = &bar; // relocation against ".bss" section
Fo the kernel ptr1 and ptr2 has point to the same arena's map_fd
while ptr3 points to a different global array's map_fd.
For the verifier:
ptr1->type == unknown_scalar
ptr2->type == const_ptr_to_map
ptr3->type == ptr_to_map_value
After verification, from JIT pov all 3 ptr-s are normal ld_imm64 insns.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20240308010812.89848-11-alexei.starovoitov@gmail.com
mmap() bpf_arena right after creation, since the kernel needs to
remember the address returned from mmap. This is user_vm_start.
LLVM will generate bpf_arena_cast_user() instructions where
necessary and JIT will add upper 32-bit of user_vm_start
to such pointers.
Fix up bpf_map_mmap_sz() to compute mmap size as
map->value_size * map->max_entries for arrays and
PAGE_SIZE * map->max_entries for arena.
Don't set BTF at arena creation time, since it doesn't support it.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240308010812.89848-9-alexei.starovoitov@gmail.com
Commit 25b146c5b8 ("kbuild: allow Kbuild to start from any directory")
exported abs_srctree and abs_objtree to avoid recomputation after the
sub-make. However, this approach turned out to be fragile.
Commit 5fa94ceb79 ("kbuild: set correct abs_srctree and abs_objtree
for package builds") moved them above "ifneq ($(sub_make_done),1)",
eliminating the need for exporting them.
These are only needed in the top Makefile. If an absolute path is
required in sub-directories, you can use $(abspath ) or $(realpath )
as needed.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
__uint() macro that is used to specify map attributes like:
__uint(type, BPF_MAP_TYPE_ARRAY);
__uint(map_flags, BPF_F_MMAPABLE);
It is limited to 32-bit, since BTF_KIND_ARRAY has u32 "number of elements"
field in "struct btf_array".
Introduce __ulong() macro that allows specifying values bigger than 32-bit.
In map definition "map_extra" is the only u64 field, so far.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20240307031228.42896-5-alexei.starovoitov@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Optional struct_ops maps are defined using question mark at the start
of the section name, e.g.:
SEC("?.struct_ops")
struct test_ops optional_map = { ... };
This commit teaches libbpf to detect if kernel allows '?' prefix
in datasec names, and if it doesn't then to rewrite such names
by replacing '?' with '_', e.g.:
DATASEC ?.struct_ops -> DATASEC _.struct_ops
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240306104529.6453-13-eddyz87@gmail.com
The next patch would add two new section names for struct_ops maps.
To make working with multiple struct_ops sections more convenient:
- remove fields like elf_state->st_ops_{shndx,link_shndx};
- mark section descriptions hosting struct_ops as
elf_sec_desc->sec_type == SEC_ST_OPS;
After these changes struct_ops sections could be processed uniformly
by iterating bpf_object->efile.secs entries.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240306104529.6453-11-eddyz87@gmail.com
Automatically select which struct_ops programs to load depending on
which struct_ops maps are selected for automatic creation.
E.g. for the BPF code below:
SEC("struct_ops/test_1") int BPF_PROG(foo) { ... }
SEC("struct_ops/test_2") int BPF_PROG(bar) { ... }
SEC(".struct_ops.link")
struct test_ops___v1 A = {
.foo = (void *)foo
};
SEC(".struct_ops.link")
struct test_ops___v2 B = {
.foo = (void *)foo,
.bar = (void *)bar,
};
And the following libbpf API calls:
bpf_map__set_autocreate(skel->maps.A, true);
bpf_map__set_autocreate(skel->maps.B, false);
The autoload would be enabled for program 'foo' and disabled for
program 'bar'.
During load, for each struct_ops program P, referenced from some
struct_ops map M:
- set P.autoload = true if M.autocreate is true for some M;
- set P.autoload = false if M.autocreate is false for all M;
- don't change P.autoload, if P is not referenced from any map.
Do this after bpf_object__init_kern_struct_ops_maps()
to make sure that shadow vars assignment is done.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240306104529.6453-9-eddyz87@gmail.com
Skip load steps for struct_ops maps not marked for automatic creation.
This should allow to load bpf object in situations like below:
SEC("struct_ops/foo") int BPF_PROG(foo) { ... }
SEC("struct_ops/bar") int BPF_PROG(bar) { ... }
struct test_ops___v1 {
int (*foo)(void);
};
struct test_ops___v2 {
int (*foo)(void);
int (*does_not_exist)(void);
};
SEC(".struct_ops.link")
struct test_ops___v1 map_for_old = {
.test_1 = (void *)foo
};
SEC(".struct_ops.link")
struct test_ops___v2 map_for_new = {
.test_1 = (void *)foo,
.does_not_exist = (void *)bar
};
Suppose program is loaded on old kernel that does not have definition
for 'does_not_exist' struct_ops member. After this commit it would be
possible to load such object file after the following tweaks:
bpf_program__set_autoload(skel->progs.bar, false);
bpf_map__set_autocreate(skel->maps.map_for_new, false);
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/bpf/20240306104529.6453-4-eddyz87@gmail.com
Enforce the following existing limitation on struct_ops programs based
on kernel BTF id instead of program-local BTF id:
struct_ops BPF prog can be re-used between multiple .struct_ops &
.struct_ops.link as long as it's the same struct_ops struct
definition and the same function pointer field
This allows reusing same BPF program for versioned struct_ops map
definitions, e.g.:
SEC("struct_ops/test")
int BPF_PROG(foo) { ... }
struct some_ops___v1 { int (*test)(void); };
struct some_ops___v2 { int (*test)(void); };
SEC(".struct_ops.link") struct some_ops___v1 a = { .test = foo }
SEC(".struct_ops.link") struct some_ops___v2 b = { .test = foo }
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240306104529.6453-3-eddyz87@gmail.com
E.g. allow the following struct_ops definitions:
struct bpf_testmod_ops___v1 { int (*test)(void); };
struct bpf_testmod_ops___v2 { int (*test)(void); };
SEC(".struct_ops.link")
struct bpf_testmod_ops___v1 a = { .test = ... }
SEC(".struct_ops.link")
struct bpf_testmod_ops___v2 b = { .test = ... }
Where both bpf_testmod_ops__v1 and bpf_testmod_ops__v2 would be
resolved as 'struct bpf_testmod_ops' from kernel BTF.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: David Vernet <void@manifault.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240306104529.6453-2-eddyz87@gmail.com
