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The arena_list selftest uses (1ull << 32) in the mmap address
computation for arm64. Use the same in the verifier_arena selftest.
This makes the selftest pass for arm64 on the CI[1].
[1] https://github.com/kernel-patches/bpf/pull/6622
Signed-off-by: Puranjay Mohan <puranjay12@gmail.com>
Link: https://lore.kernel.org/r/20240322133552.70681-1-puranjay12@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Check that 4Gbyte arena can be allocated and overflow/underflow access in
the first and the last page behaves as expected.
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/20240315021834.62988-5-alexei.starovoitov@gmail.com
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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
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https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:
====================
pull-request: bpf-next 2024-03-11
We've added 59 non-merge commits during the last 9 day(s) which contain
a total of 88 files changed, 4181 insertions(+), 590 deletions(-).
The main changes are:
1) Enforce VM_IOREMAP flag and range in ioremap_page_range and introduce
VM_SPARSE kind and vm_area_[un]map_pages to be used in bpf_arena,
from Alexei.
2) Introduce bpf_arena which is sparse shared memory region between bpf
program and user space where structures inside the arena can have
pointers to other areas of the arena, and pointers work seamlessly for
both user-space programs and bpf programs, from Alexei and Andrii.
3) Introduce may_goto instruction that is a contract between the verifier
and the program. The verifier allows the program to loop assuming it's
behaving well, but reserves the right to terminate it, from Alexei.
4) Use IETF format for field definitions in the BPF standard
document, from Dave.
5) Extend struct_ops libbpf APIs to allow specify version suffixes for
stuct_ops map types, share the same BPF program between several map
definitions, and other improvements, from Eduard.
6) Enable struct_ops support for more than one page in trampolines,
from Kui-Feng.
7) Support kCFI + BPF on riscv64, from Puranjay.
8) Use bpf_prog_pack for arm64 bpf trampoline, from Puranjay.
9) Fix roundup_pow_of_two undefined behavior on 32-bit archs, from Toke.
====================
Link: https://lore.kernel.org/r/20240312003646.8692-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Adding kprobe multi triggering benchmarks. It's useful now to bench
new fprobe implementation and might be useful later as well.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240311211023.590321-1-jolsa@kernel.org
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bpf_arena_htab.h - hash table implemented as bpf program
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240308010812.89848-15-alexei.starovoitov@gmail.com
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bpf_arena_alloc.h - implements page_frag allocator as a bpf program.
bpf_arena_list.h - doubly linked link list as a bpf program.
Compiled as a bpf program and as native C code.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240308010812.89848-14-alexei.starovoitov@gmail.com
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Add unit tests for bpf_arena_alloc/free_pages() functionality
and bpf_arena_common.h with a set of common helpers and macros that
is used in this test and the following patches.
Also modify test_loader that didn't support running bpf_prog_type_syscall
programs.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240308010812.89848-13-alexei.starovoitov@gmail.com
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We already have kprobe and fentry benchmarks. Let's add kretprobe and
fexit ones for completeness.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20240309005124.3004446-1-andrii@kernel.org
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Cross-merge networking fixes after downstream PR.
No conflicts.
Adjacent changes:
net/core/page_pool_user.c
0b11b1c5c320 ("netdev: let netlink core handle -EMSGSIZE errors")
429679dcf7d9 ("page_pool: fix netlink dump stop/resume")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Check that "?.struct_ops" and "?.struct_ops.link" section names define
struct_ops maps with autocreate == false after open.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240306104529.6453-14-eddyz87@gmail.com
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Check that autocreate flags of struct_ops map cause autoload of
struct_ops corresponding programs:
- when struct_ops program is referenced only from a map for which
autocreate is set to false, that program should not be loaded;
- when struct_ops program with autoload == false is set to be used
from a map with autocreate == true using shadow var,
that program should be loaded;
- when struct_ops program is not referenced from any map object load
should fail.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240306104529.6453-10-eddyz87@gmail.com
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Check that bpf_map__set_autocreate() can be used to disable automatic
creation for struct_ops maps.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240306104529.6453-8-eddyz87@gmail.com
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When loading struct_ops programs kernel requires BTF id of the
struct_ops type and member index for attachment point inside that
type. This makes impossible to use same BPF program in several
struct_ops maps that have different struct_ops type.
Check if libbpf rejects such BPF objects files.
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/20240306104529.6453-7-eddyz87@gmail.com
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Extend struct_ops_module test case to check if it is possible to use
'___' suffixes for struct_ops type specification.
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/20240306104529.6453-5-eddyz87@gmail.com
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Add tests for may_goto instruction via cond_break macro.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Tested-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20240306031929.42666-5-alexei.starovoitov@gmail.com
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The test case was minimized from mailing list discussion [0].
It is equivalent to the following C program:
struct iter_limit_bug_ctx { __u64 a; __u64 b; __u64 c; };
static __naked void iter_limit_bug_cb(void)
{
switch (bpf_get_prandom_u32()) {
case 1: ctx->a = 42; break;
case 2: ctx->b = 42; break;
default: ctx->c = 42; break;
}
}
int iter_limit_bug(struct __sk_buff *skb)
{
struct iter_limit_bug_ctx ctx = { 7, 7, 7 };
bpf_loop(2, iter_limit_bug_cb, &ctx, 0);
if (ctx.a == 42 && ctx.b == 42 && ctx.c == 7)
asm volatile("r1 /= 0;":::"r1");
return 0;
}
The main idea is that each loop iteration changes one of the state
variables in a non-deterministic manner. Hence it is premature to
prune the states that have two iterations left comparing them to
states with one iteration left.
E.g. {{7,7,7}, callback_depth=0} can reach state {42,42,7},
while {{7,7,7}, callback_depth=1} can't.
[0] https://lore.kernel.org/bpf/9b251840-7cb8-4d17-bd23-1fc8071d8eef@linux.dev/
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240222154121.6991-3-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Create and load a struct_ops map with a large number of struct_ops
programs to generate trampolines taking a size over multiple pages. The
map includes 40 programs. Their trampolines takes 6.6k+, more than 1.5
pages, on x86.
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/20240224223418.526631-4-thinker.li@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
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https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:
====================
pull-request: bpf-next 2024-02-29
We've added 119 non-merge commits during the last 32 day(s) which contain
a total of 150 files changed, 3589 insertions(+), 995 deletions(-).
The main changes are:
1) Extend the BPF verifier to enable static subprog calls in spin lock
critical sections, from Kumar Kartikeya Dwivedi.
2) Fix confusing and incorrect inference of PTR_TO_CTX argument type
in BPF global subprogs, from Andrii Nakryiko.
3) Larger batch of riscv BPF JIT improvements and enabling inlining
of the bpf_kptr_xchg() for RV64, from Pu Lehui.
4) Allow skeleton users to change the values of the fields in struct_ops
maps at runtime, from Kui-Feng Lee.
5) Extend the verifier's capabilities of tracking scalars when they
are spilled to stack, especially when the spill or fill is narrowing,
from Maxim Mikityanskiy & Eduard Zingerman.
6) Various BPF selftest improvements to fix errors under gcc BPF backend,
from Jose E. Marchesi.
7) Avoid module loading failure when the module trying to register
a struct_ops has its BTF section stripped, from Geliang Tang.
8) Annotate all kfuncs in .BTF_ids section which eventually allows
for automatic kfunc prototype generation from bpftool, from Daniel Xu.
9) Several updates to the instruction-set.rst IETF standardization
document, from Dave Thaler.
10) Shrink the size of struct bpf_map resp. bpf_array,
from Alexei Starovoitov.
11) Initial small subset of BPF verifier prepwork for sleepable bpf_timer,
from Benjamin Tissoires.
12) Fix bpftool to be more portable to musl libc by using POSIX's
basename(), from Arnaldo Carvalho de Melo.
13) Add libbpf support to gcc in CORE macro definitions,
from Cupertino Miranda.
14) Remove a duplicate type check in perf_event_bpf_event,
from Florian Lehner.
15) Fix bpf_spin_{un,}lock BPF helpers to actually annotate them
with notrace correctly, from Yonghong Song.
16) Replace the deprecated bpf_lpm_trie_key 0-length array with flexible
array to fix build warnings, from Kees Cook.
17) Fix resolve_btfids cross-compilation to non host-native endianness,
from Viktor Malik.
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (119 commits)
selftests/bpf: Test if shadow types work correctly.
bpftool: Add an example for struct_ops map and shadow type.
bpftool: Generated shadow variables for struct_ops maps.
libbpf: Convert st_ops->data to shadow type.
libbpf: Set btf_value_type_id of struct bpf_map for struct_ops.
bpf: Replace bpf_lpm_trie_key 0-length array with flexible array
bpf, arm64: use bpf_prog_pack for memory management
arm64: patching: implement text_poke API
bpf, arm64: support exceptions
arm64: stacktrace: Implement arch_bpf_stack_walk() for the BPF JIT
bpf: add is_async_callback_calling_insn() helper
bpf: introduce in_sleepable() helper
bpf: allow more maps in sleepable bpf programs
selftests/bpf: Test case for lacking CFI stub functions.
bpf: Check cfi_stubs before registering a struct_ops type.
bpf: Clarify batch lookup/lookup_and_delete semantics
bpf, docs: specify which BPF_ABS and BPF_IND fields were zero
bpf, docs: Fix typos in instruction-set.rst
selftests/bpf: update tcp_custom_syncookie to use scalar packet offset
bpf: Shrink size of struct bpf_map/bpf_array.
...
====================
Link: https://lore.kernel.org/r/20240301001625.8800-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Change the values of fields, including scalar types and function pointers,
and check if the struct_ops map works as expected.
The test changes the field "test_2" of "testmod_1" from the pointer to
test_2() to pointer to test_3() and the field "data" to 13. The function
test_2() and test_3() both compute a new value for "test_2_result", but in
different way. By checking the value of "test_2_result", it ensures the
struct_ops map works as expected with changes through shadow types.
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240229064523.2091270-6-thinker.li@gmail.com
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Replace deprecated 0-length array in struct bpf_lpm_trie_key with
flexible array. Found with GCC 13:
../kernel/bpf/lpm_trie.c:207:51: warning: array subscript i is outside array bounds of 'const __u8[0]' {aka 'const unsigned char[]'} [-Warray-bounds=]
207 | *(__be16 *)&key->data[i]);
| ^~~~~~~~~~~~~
../include/uapi/linux/swab.h:102:54: note: in definition of macro '__swab16'
102 | #define __swab16(x) (__u16)__builtin_bswap16((__u16)(x))
| ^
../include/linux/byteorder/generic.h:97:21: note: in expansion of macro '__be16_to_cpu'
97 | #define be16_to_cpu __be16_to_cpu
| ^~~~~~~~~~~~~
../kernel/bpf/lpm_trie.c:206:28: note: in expansion of macro 'be16_to_cpu'
206 | u16 diff = be16_to_cpu(*(__be16 *)&node->data[i]
^
| ^~~~~~~~~~~
In file included from ../include/linux/bpf.h:7:
../include/uapi/linux/bpf.h:82:17: note: while referencing 'data'
82 | __u8 data[0]; /* Arbitrary size */
| ^~~~
And found at run-time under CONFIG_FORTIFY_SOURCE:
UBSAN: array-index-out-of-bounds in kernel/bpf/lpm_trie.c:218:49
index 0 is out of range for type '__u8 [*]'
Changing struct bpf_lpm_trie_key is difficult since has been used by
userspace. For example, in Cilium:
struct egress_gw_policy_key {
struct bpf_lpm_trie_key lpm_key;
__u32 saddr;
__u32 daddr;
};
While direct references to the "data" member haven't been found, there
are static initializers what include the final member. For example,
the "{}" here:
struct egress_gw_policy_key in_key = {
.lpm_key = { 32 + 24, {} },
.saddr = CLIENT_IP,
.daddr = EXTERNAL_SVC_IP & 0Xffffff,
};
To avoid the build time and run time warnings seen with a 0-sized
trailing array for struct bpf_lpm_trie_key, introduce a new struct
that correctly uses a flexible array for the trailing bytes,
struct bpf_lpm_trie_key_u8. As part of this, include the "header"
portion (which is just the "prefixlen" member), so it can be used
by anything building a bpf_lpr_trie_key that has trailing members that
aren't a u8 flexible array (like the self-test[1]), which is named
struct bpf_lpm_trie_key_hdr.
Unfortunately, C++ refuses to parse the __struct_group() helper, so
it is not possible to define struct bpf_lpm_trie_key_hdr directly in
struct bpf_lpm_trie_key_u8, so we must open-code the union directly.
Adjust the kernel code to use struct bpf_lpm_trie_key_u8 through-out,
and for the selftest to use struct bpf_lpm_trie_key_hdr. Add a comment
to the UAPI header directing folks to the two new options.
Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Closes: https://paste.debian.net/hidden/ca500597/
Link: https://lore.kernel.org/all/202206281009.4332AA33@keescook/ [1]
Link: https://lore.kernel.org/bpf/20240222155612.it.533-kees@kernel.org
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Cross-merge networking fixes after downstream PR.
Conflicts:
net/ipv4/udp.c
f796feabb9f5 ("udp: add local "peek offset enabled" flag")
56667da7399e ("net: implement lockless setsockopt(SO_PEEK_OFF)")
Adjacent changes:
net/unix/garbage.c
aa82ac51d633 ("af_unix: Drop oob_skb ref before purging queue in GC.")
11498715f266 ("af_unix: Remove io_uring code for GC.")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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This commit updates tcp_custom_syncookie.c:tcp_parse_option() to use
explicit packet offset (ctx->off) for packet access instead of ever
moving pointer (ctx->ptr), this reduces verification complexity:
- the tcp_parse_option() is passed as a callback to bpf_loop();
- suppose a checkpoint is created each time at function entry;
- the ctx->ptr is tracked by verifier as PTR_TO_PACKET;
- the ctx->ptr is incremented in tcp_parse_option(),
thus umax_value field tracked for it is incremented as well;
- on each next iteration of tcp_parse_option()
checkpoint from a previous iteration can't be reused
for state pruning, because PTR_TO_PACKET registers are
considered equivalent only if old->umax_value >= cur->umax_value;
- on the other hand, the ctx->off is a SCALAR,
subject to widen_imprecise_scalars();
- it's exact bounds are eventually forgotten and it is tracked as
unknown scalar at entry to tcp_parse_option();
- hence checkpoints created at the start of the function eventually
converge.
The change is similar to one applied in [0] to xdp_synproxy_kern.c.
Comparing before and after with veristat yields following results:
File Insns (A) Insns (B) Insns (DIFF)
------------------------------- --------- --------- -----------------
test_tcp_custom_syncookie.bpf.o 466657 12423 -454234 (-97.34%)
[0] commit 977bc146d4eb ("selftests/bpf: track tcp payload offset as scalar in xdp_synproxy")
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240222150300.14909-2-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Incorporate a test case to assess the handling of invalid flags or
task__nullable parameters passed to bpf_iter_task_new(). Prior to the
preceding commit, this scenario could potentially trigger a kernel panic.
However, with the previous commit, this test case is expected to function
correctly.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240217114152.1623-3-laoar.shao@gmail.com
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bpf_timer_cancel
This selftest is based on a Alexei's test adopted from an internal
user to troubleshoot another bug. During this exercise, a separate
racing bug was discovered between bpf_timer_cancel_and_free
and bpf_timer_cancel. The details can be found in the previous
patch.
This patch is to add a selftest that can trigger the bug.
I can trigger the UAF everytime in my qemu setup with KASAN. The idea
is to have multiple user space threads running in a tight loop to exercise
both bpf_map_update_elem (which calls into bpf_timer_cancel_and_free)
and bpf_timer_cancel.
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/bpf/20240215211218.990808-2-martin.lau@linux.dev
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Under x86-64, when using bpf_probe_read_kernel{_str}() or
bpf_probe_read{_str}() to read vsyscall page, the read may trigger oops,
so add one test case to ensure that the problem is fixed. Beside those
four bpf helpers mentioned above, testing the read of vsyscall page by
using bpf_probe_read_user{_str} and bpf_copy_from_user{_task}() as well.
The test case passes the address of vsyscall page to these six helpers
and checks whether the returned values are expected:
1) For bpf_probe_read_kernel{_str}()/bpf_probe_read{_str}(), the
expected return value is -ERANGE as shown below:
bpf_probe_read_kernel_common
copy_from_kernel_nofault
// false, return -ERANGE
copy_from_kernel_nofault_allowed
2) For bpf_probe_read_user{_str}(), the expected return value is -EFAULT
as show below:
bpf_probe_read_user_common
copy_from_user_nofault
// false, return -EFAULT
__access_ok
3) For bpf_copy_from_user(), the expected return value is -EFAULT:
// return -EFAULT
bpf_copy_from_user
copy_from_user
_copy_from_user
// return false
access_ok
4) For bpf_copy_from_user_task(), the expected return value is -EFAULT:
// return -EFAULT
bpf_copy_from_user_task
access_process_vm
// return 0
vma_lookup()
// return 0
expand_stack()
The occurrence of oops depends on the availability of CPU SMAP [1]
feature and there are three possible configurations of vsyscall page in
the boot cmd-line: vsyscall={xonly|none|emulate}, so there are a total
of six possible combinations. Under all these combinations, the test
case runs successfully.
[1]: https://en.wikipedia.org/wiki/Supervisor_Mode_Access_Prevention
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20240202103935.3154011-4-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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With latest llvm19, I hit the following selftest failures with
$ ./test_progs -j
libbpf: prog 'on_event': BPF program load failed: Permission denied
libbpf: prog 'on_event': -- BEGIN PROG LOAD LOG --
combined stack size of 4 calls is 544. Too large
verification time 1344153 usec
stack depth 24+440+0+32
processed 51008 insns (limit 1000000) max_states_per_insn 19 total_states 1467 peak_states 303 mark_read 146
-- END PROG LOAD LOG --
libbpf: prog 'on_event': failed to load: -13
libbpf: failed to load object 'strobemeta_subprogs.bpf.o'
scale_test:FAIL:expect_success unexpected error: -13 (errno 13)
#498 verif_scale_strobemeta_subprogs:FAIL
The verifier complains too big of the combined stack size (544 bytes) which
exceeds the maximum stack limit 512. This is a regression from llvm19 ([1]).
In the above error log, the original stack depth is 24+440+0+32.
To satisfy interpreter's need, in verifier the stack depth is adjusted to
32+448+32+32=544 which exceeds 512, hence the error. The same adjusted
stack size is also used for jit case.
But the jitted codes could use smaller stack size.
$ egrep -r stack_depth | grep round_up
arm64/net/bpf_jit_comp.c: ctx->stack_size = round_up(prog->aux->stack_depth, 16);
loongarch/net/bpf_jit.c: bpf_stack_adjust = round_up(ctx->prog->aux->stack_depth, 16);
powerpc/net/bpf_jit_comp.c: cgctx.stack_size = round_up(fp->aux->stack_depth, 16);
riscv/net/bpf_jit_comp32.c: round_up(ctx->prog->aux->stack_depth, STACK_ALIGN);
riscv/net/bpf_jit_comp64.c: bpf_stack_adjust = round_up(ctx->prog->aux->stack_depth, 16);
s390/net/bpf_jit_comp.c: u32 stack_depth = round_up(fp->aux->stack_depth, 8);
sparc/net/bpf_jit_comp_64.c: stack_needed += round_up(stack_depth, 16);
x86/net/bpf_jit_comp.c: EMIT3_off32(0x48, 0x81, 0xEC, round_up(stack_depth, 8));
x86/net/bpf_jit_comp.c: int tcc_off = -4 - round_up(stack_depth, 8);
x86/net/bpf_jit_comp.c: round_up(stack_depth, 8));
x86/net/bpf_jit_comp.c: int tcc_off = -4 - round_up(stack_depth, 8);
x86/net/bpf_jit_comp.c: EMIT3_off32(0x48, 0x81, 0xC4, round_up(stack_depth, 8));
In the above, STACK_ALIGN in riscv/net/bpf_jit_comp32.c is defined as 16.
So stack is aligned in either 8 or 16, x86/s390 having 8-byte stack alignment and
the rest having 16-byte alignment.
This patch calculates total stack depth based on 16-byte alignment if jit is requested.
For the above failing case, the new stack size will be 32+448+0+32=512 and no verification
failure. llvm19 regression will be discussed separately in llvm upstream.
The verifier change caused three test failures as these tests compared messages
with stack size. More specifically,
- test_global_funcs/global_func1: fail with interpreter mode and success with jit mode.
Adjusted stack sizes so both jit and interpreter modes will fail.
- async_stack_depth/{pseudo_call_check, async_call_root_check}: since jit and interpreter
will calculate different stack sizes, the failure msg is adjusted to omit those
specific stack size numbers.
[1] https://lore.kernel.org/bpf/32bde0f0-1881-46c9-931a-673be566c61d@linux.dev/
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240214232951.4113094-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
Add tests validating that kernel handles pointer to anonymous struct
argument as PTR_TO_MEM case, not as PTR_TO_CTX case.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240212233221.2575350-5-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
For program types that don't have named context type name (e.g., BPF
iterator programs or tracepoint programs), ctx_tname will be a non-NULL
empty string. For such programs it shouldn't be possible to have
PTR_TO_CTX argument for global subprogs based on type name alone.
arg:ctx tag is the only way to have PTR_TO_CTX passed into global
subprog for such program types.
Fix this loophole, which currently would assume PTR_TO_CTX whenever
user uses a pointer to anonymous struct as an argument to their global
subprogs. This happens in practice with the following (quite common, in
practice) approach:
typedef struct { /* anonymous */
int x;
} my_type_t;
int my_subprog(my_type_t *arg) { ... }
User's intent is to have PTR_TO_MEM argument for `arg`, but verifier
will complain about expecting PTR_TO_CTX.
This fix also closes unintended s390x-specific KPROBE handling of
PTR_TO_CTX case. Selftest change is necessary to accommodate this.
Fixes: 91cc1a99740e ("bpf: Annotate context types")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240212233221.2575350-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
Test if the verifier verifies nullable pointer arguments correctly for BPF
struct_ops programs.
"test_maybe_null" in struct bpf_testmod_ops is the operator defined for the
test cases here.
A BPF program should check a pointer for NULL beforehand to access the
value pointed by the nullable pointer arguments, or the verifier should
reject the programs. The test here includes two parts; the programs
checking pointers properly and the programs not checking pointers
beforehand. The test checks if the verifier accepts the programs checking
properly and rejects the programs not checking at all.
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/20240209023750.1153905-5-thinker.li@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
|
|
[Changes from V1:
- Avoid conflict by rebasing with latest master.]
Some BPF tests use loop unrolling compiler pragmas that are clang
specific and not supported by GCC. These pragmas, along with their
GCC equivalences are:
#pragma clang loop unroll_count(N)
#pragma GCC unroll N
#pragma clang loop unroll(full)
#pragma GCC unroll 65534
#pragma clang loop unroll(disable)
#pragma GCC unroll 1
#pragma unroll [aka #pragma clang loop unroll(enable)]
There is no GCC equivalence to this pragma. It enables unrolling on
loops that the compiler would not ordinarily unroll even with
-O2|-funroll-loops, but it is not equivalent to full unrolling
either.
This patch adds a new header progs/bpf_compiler.h that defines the
following macros, which correspond to each pair of compiler-specific
pragmas above:
__pragma_loop_unroll_count(N)
__pragma_loop_unroll_full
__pragma_loop_no_unroll
__pragma_loop_unroll
The selftests using loop unrolling pragmas are then changed to include
the header and use these macros in place of the explicit pragmas.
Tested in bpf-next master.
No regressions.
Signed-off-by: Jose E. Marchesi <jose.marchesi@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20240208203612.29611-1-jose.marchesi@oracle.com
|
|
Add two tests to ensure fentry programs cannot attach to
bpf_spin_{lock,unlock}() helpers. The tracing_failure.c files
can be used in the future for other tracing failure cases.
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240207070107.335341-1-yonghong.song@linux.dev
|
|
In various performance profiles of kernels with BPF programs attached,
bpf_local_storage_lookup() appears as a significant portion of CPU
cycles spent. To enable the compiler generate more optimal code, turn
bpf_local_storage_lookup() into a static inline function, where only the
cache insertion code path is outlined
Notably, outlining cache insertion helps avoid bloating callers by
duplicating setting up calls to raw_spin_{lock,unlock}_irqsave() (on
architectures which do not inline spin_lock/unlock, such as x86), which
would cause the compiler produce worse code by deciding to outline
otherwise inlinable functions. The call overhead is neutral, because we
make 2 calls either way: either calling raw_spin_lock_irqsave() and
raw_spin_unlock_irqsave(); or call __bpf_local_storage_insert_cache(),
which calls raw_spin_lock_irqsave(), followed by a tail-call to
raw_spin_unlock_irqsave() where the compiler can perform TCO and (in
optimized uninstrumented builds) turns it into a plain jump. The call to
__bpf_local_storage_insert_cache() can be elided entirely if
cacheit_lockit is a false constant expression.
Based on results from './benchs/run_bench_local_storage.sh' (21 trials,
reboot between each trial; x86 defconfig + BPF, clang 16) this produces
improvements in throughput and latency in the majority of cases, with an
average (geomean) improvement of 8%:
+---- Hashmap Control --------------------
|
| + num keys: 10
| : <before> | <after>
| +-+ hashmap (control) sequential get +----------------------+----------------------
| +- hits throughput | 14.789 M ops/s | 14.745 M ops/s ( ~ )
| +- hits latency | 67.679 ns/op | 67.879 ns/op ( ~ )
| +- important_hits throughput | 14.789 M ops/s | 14.745 M ops/s ( ~ )
|
| + num keys: 1000
| : <before> | <after>
| +-+ hashmap (control) sequential get +----------------------+----------------------
| +- hits throughput | 12.233 M ops/s | 12.170 M ops/s ( ~ )
| +- hits latency | 81.754 ns/op | 82.185 ns/op ( ~ )
| +- important_hits throughput | 12.233 M ops/s | 12.170 M ops/s ( ~ )
|
| + num keys: 10000
| : <before> | <after>
| +-+ hashmap (control) sequential get +----------------------+----------------------
| +- hits throughput | 7.220 M ops/s | 7.204 M ops/s ( ~ )
| +- hits latency | 138.522 ns/op | 138.842 ns/op ( ~ )
| +- important_hits throughput | 7.220 M ops/s | 7.204 M ops/s ( ~ )
|
| + num keys: 100000
| : <before> | <after>
| +-+ hashmap (control) sequential get +----------------------+----------------------
| +- hits throughput | 5.061 M ops/s | 5.165 M ops/s (+2.1%)
| +- hits latency | 198.483 ns/op | 194.270 ns/op (-2.1%)
| +- important_hits throughput | 5.061 M ops/s | 5.165 M ops/s (+2.1%)
|
| + num keys: 4194304
| : <before> | <after>
| +-+ hashmap (control) sequential get +----------------------+----------------------
| +- hits throughput | 2.864 M ops/s | 2.882 M ops/s ( ~ )
| +- hits latency | 365.220 ns/op | 361.418 ns/op (-1.0%)
| +- important_hits throughput | 2.864 M ops/s | 2.882 M ops/s ( ~ )
|
+---- Local Storage ----------------------
|
| + num_maps: 1
| : <before> | <after>
| +-+ local_storage cache sequential get +----------------------+----------------------
| +- hits throughput | 33.005 M ops/s | 39.068 M ops/s (+18.4%)
| +- hits latency | 30.300 ns/op | 25.598 ns/op (-15.5%)
| +- important_hits throughput | 33.005 M ops/s | 39.068 M ops/s (+18.4%)
| :
| : <before> | <after>
| +-+ local_storage cache interleaved get +----------------------+----------------------
| +- hits throughput | 37.151 M ops/s | 44.926 M ops/s (+20.9%)
| +- hits latency | 26.919 ns/op | 22.259 ns/op (-17.3%)
| +- important_hits throughput | 37.151 M ops/s | 44.926 M ops/s (+20.9%)
|
| + num_maps: 10
| : <before> | <after>
| +-+ local_storage cache sequential get +----------------------+----------------------
| +- hits throughput | 32.288 M ops/s | 38.099 M ops/s (+18.0%)
| +- hits latency | 30.972 ns/op | 26.248 ns/op (-15.3%)
| +- important_hits throughput | 3.229 M ops/s | 3.810 M ops/s (+18.0%)
| :
| : <before> | <after>
| +-+ local_storage cache interleaved get +----------------------+----------------------
| +- hits throughput | 34.473 M ops/s | 41.145 M ops/s (+19.4%)
| +- hits latency | 29.010 ns/op | 24.307 ns/op (-16.2%)
| +- important_hits throughput | 12.312 M ops/s | 14.695 M ops/s (+19.4%)
|
| + num_maps: 16
| : <before> | <after>
| +-+ local_storage cache sequential get +----------------------+----------------------
| +- hits throughput | 32.524 M ops/s | 38.341 M ops/s (+17.9%)
| +- hits latency | 30.748 ns/op | 26.083 ns/op (-15.2%)
| +- important_hits throughput | 2.033 M ops/s | 2.396 M ops/s (+17.9%)
| :
| : <before> | <after>
| +-+ local_storage cache interleaved get +----------------------+----------------------
| +- hits throughput | 34.575 M ops/s | 41.338 M ops/s (+19.6%)
| +- hits latency | 28.925 ns/op | 24.193 ns/op (-16.4%)
| +- important_hits throughput | 11.001 M ops/s | 13.153 M ops/s (+19.6%)
|
| + num_maps: 17
| : <before> | <after>
| +-+ local_storage cache sequential get +----------------------+----------------------
| +- hits throughput | 28.861 M ops/s | 32.756 M ops/s (+13.5%)
| +- hits latency | 34.649 ns/op | 30.530 ns/op (-11.9%)
| +- important_hits throughput | 1.700 M ops/s | 1.929 M ops/s (+13.5%)
| :
| : <before> | <after>
| +-+ local_storage cache interleaved get +----------------------+----------------------
| +- hits throughput | 31.529 M ops/s | 36.110 M ops/s (+14.5%)
| +- hits latency | 31.719 ns/op | 27.697 ns/op (-12.7%)
| +- important_hits throughput | 9.598 M ops/s | 10.993 M ops/s (+14.5%)
|
| + num_maps: 24
| : <before> | <after>
| +-+ local_storage cache sequential get +----------------------+----------------------
| +- hits throughput | 18.602 M ops/s | 19.937 M ops/s (+7.2%)
| +- hits latency | 53.767 ns/op | 50.166 ns/op (-6.7%)
| +- important_hits throughput | 0.776 M ops/s | 0.831 M ops/s (+7.2%)
| :
| : <before> | <after>
| +-+ local_storage cache interleaved get +----------------------+----------------------
| +- hits throughput | 21.718 M ops/s | 23.332 M ops/s (+7.4%)
| +- hits latency | 46.047 ns/op | 42.865 ns/op (-6.9%)
| +- important_hits throughput | 6.110 M ops/s | 6.564 M ops/s (+7.4%)
|
| + num_maps: 32
| : <before> | <after>
| +-+ local_storage cache sequential get +----------------------+----------------------
| +- hits throughput | 14.118 M ops/s | 14.626 M ops/s (+3.6%)
| +- hits latency | 70.856 ns/op | 68.381 ns/op (-3.5%)
| +- important_hits throughput | 0.442 M ops/s | 0.458 M ops/s (+3.6%)
| :
| : <before> | <after>
| +-+ local_storage cache interleaved get +----------------------+----------------------
| +- hits throughput | 17.111 M ops/s | 17.906 M ops/s (+4.6%)
| +- hits latency | 58.451 ns/op | 55.865 ns/op (-4.4%)
| +- important_hits throughput | 4.776 M ops/s | 4.998 M ops/s (+4.6%)
|
| + num_maps: 100
| : <before> | <after>
| +-+ local_storage cache sequential get +----------------------+----------------------
| +- hits throughput | 5.281 M ops/s | 5.528 M ops/s (+4.7%)
| +- hits latency | 192.398 ns/op | 183.059 ns/op (-4.9%)
| +- important_hits throughput | 0.053 M ops/s | 0.055 M ops/s (+4.9%)
| :
| : <before> | <after>
| +-+ local_storage cache interleaved get +----------------------+----------------------
| +- hits throughput | 6.265 M ops/s | 6.498 M ops/s (+3.7%)
| +- hits latency | 161.436 ns/op | 152.877 ns/op (-5.3%)
| +- important_hits throughput | 1.636 M ops/s | 1.697 M ops/s (+3.7%)
|
| + num_maps: 1000
| : <before> | <after>
| +-+ local_storage cache sequential get +----------------------+----------------------
| +- hits throughput | 0.355 M ops/s | 0.354 M ops/s ( ~ )
| +- hits latency | 2826.538 ns/op | 2827.139 ns/op ( ~ )
| +- important_hits throughput | 0.000 M ops/s | 0.000 M ops/s ( ~ )
| :
| : <before> | <after>
| +-+ local_storage cache interleaved get +----------------------+----------------------
| +- hits throughput | 0.404 M ops/s | 0.403 M ops/s ( ~ )
| +- hits latency | 2481.190 ns/op | 2487.555 ns/op ( ~ )
| +- important_hits throughput | 0.102 M ops/s | 0.101 M ops/s ( ~ )
The on_lookup test in {cgrp,task}_ls_recursion.c is removed
because the bpf_local_storage_lookup is no longer traceable
and adding tracepoint will make the compiler generate worse
code: https://lore.kernel.org/bpf/ZcJmok64Xqv6l4ZS@elver.google.com/
Signed-off-by: Marco Elver <elver@google.com>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240207122626.3508658-1-elver@google.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
|
|
After the series "Annotate kfuncs in .BTF_ids section"[0], kfuncs can be
generated from bpftool. Let's mark the existing cpumask kfunc declarations
__weak so they don't conflict with definitions that will eventually come
from vmlinux.h.
[0]. https://lore.kernel.org/all/cover.1706491398.git.dxu@dxuuu.xyz
Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Daniel Xu <dxu@dxuuu.xyz>
Link: https://lore.kernel.org/bpf/20240206081416.26242-5-laoar.shao@gmail.com
|
|
[Differences from V2:
- Remove conditionals in the source files pragmas, as the
pragma is supported by both GCC and clang.]
Both GCC and clang implement the -Wno-address-of-packed-member
warning, which is enabled by -Wall, that warns about taking the
address of a packed struct field when it can lead to an "unaligned"
address.
This triggers the following errors (-Werror) when building three
particular BPF selftests with GCC:
progs/test_cls_redirect.c
986 | if (ipv4_is_fragment((void *)&encap->ip)) {
progs/test_cls_redirect_dynptr.c
410 | pkt_ipv4_checksum((void *)&encap_gre->ip);
progs/test_cls_redirect.c
521 | pkt_ipv4_checksum((void *)&encap_gre->ip);
progs/test_tc_tunnel.c
232 | set_ipv4_csum((void *)&h_outer.ip);
These warnings do not signal any real problem in the tests as far as I
can see.
This patch adds pragmas to these test files that inhibit the
-Waddress-of-packed-member warning.
Tested in bpf-next master.
No regressions.
Signed-off-by: Jose E. Marchesi <jose.marchesi@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20240206102330.7113-1-jose.marchesi@oracle.com
|
|
Add selftests covering the following cases:
- A static or global subprog called from within a RCU read section works
- A static subprog taking an RCU read lock which is released in caller works
- A static subprog releasing the caller's RCU read lock works
Global subprogs that leave the lock in an imbalanced state will not
work, as they are verified separately, so ensure those cases fail as
well.
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20240205055646.1112186-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
Add selftests for static subprog calls within bpf_spin_lock critical
section, and ensure we still reject global subprog calls. Also test the
case where a subprog call will unlock the caller's held lock, or the
caller will unlock a lock taken by a subprog call, ensuring correct
transfer of lock state across frames on exit.
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20240204222349.938118-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
Currently, calling any helpers, kfuncs, or subprogs except the graph
data structure (lists, rbtrees) API kfuncs while holding a bpf_spin_lock
is not allowed. One of the original motivations of this decision was to
force the BPF programmer's hand into keeping the bpf_spin_lock critical
section small, and to ensure the execution time of the program does not
increase due to lock waiting times. In addition to this, some of the
helpers and kfuncs may be unsafe to call while holding a bpf_spin_lock.
However, when it comes to subprog calls, atleast for static subprogs,
the verifier is able to explore their instructions during verification.
Therefore, it is similar in effect to having the same code inlined into
the critical section. Hence, not allowing static subprog calls in the
bpf_spin_lock critical section is mostly an annoyance that needs to be
worked around, without providing any tangible benefit.
Unlike static subprog calls, global subprog calls are not safe to permit
within the critical section, as the verifier does not explore them
during verification, therefore whether the same lock will be taken
again, or unlocked, cannot be ascertained.
Therefore, allow calling static subprogs within a bpf_spin_lock critical
section, and only reject it in case the subprog linkage is global.
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20240204222349.938118-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
"r" is used to receive the return value of test_2 in bpf_testmod.c, but it
is not actually used. So, we remove "r" and change the return type to
"void".
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202401300557.z5vzn8FM-lkp@intel.com/
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240204061204.1864529-1-thinker.li@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
|
|
Somehow recently I frequently hit the following test failure
with either ./test_progs or ./test_progs-cpuv4:
serial_test_ptr_untrusted:PASS:skel_open 0 nsec
serial_test_ptr_untrusted:PASS:lsm_attach 0 nsec
serial_test_ptr_untrusted:PASS:raw_tp_attach 0 nsec
serial_test_ptr_untrusted:FAIL:cmp_tp_name unexpected cmp_tp_name: actual -115 != expected 0
#182 ptr_untrusted:FAIL
Further investigation found the failure is due to
bpf_probe_read_user_str()
where reading user-level string attr->raw_tracepoint.name
is not successfully, most likely due to the
string itself still in disk and not populated into memory yet.
One solution is do a printf() call of the string before doing bpf
syscall which will force the raw_tracepoint.name into memory.
But I think a more robust solution is to use bpf_copy_from_user()
which is used in sleepable program and can tolerate page fault,
and the fix here used the latter approach.
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240204194452.2785936-1-yonghong.song@linux.dev
|
|
Add extra layer of global functions to ensure that passing around
(trusted) PTR_TO_BTF_ID_OR_NULL registers works as expected. We also
extend trusted_task_arg_nullable subtest to check three possible valid
argumements: known NULL, known non-NULL, and maybe NULL cases.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240202190529.2374377-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
Check that stacksafe() compares spilled scalars with STACK_MISC.
The following combinations are explored:
- old spill of imprecise scalar is equivalent to cur STACK_{MISC,INVALID}
(plus error in unpriv mode);
- old spill of precise scalar is not equivalent to cur STACK_MISC;
- old STACK_MISC is equivalent to cur scalar;
- old STACK_MISC is not equivalent to cur non-scalar.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240127175237.526726-7-maxtram95@gmail.com
|
|
The previous commit allowed to preserve boundaries and track IDs of
scalars on narrowing fills. Add test cases for that pattern.
Signed-off-by: Maxim Mikityanskiy <maxim@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20240127175237.526726-5-maxtram95@gmail.com
|
|
When the width of a fill is smaller than the width of the preceding
spill, the information about scalar boundaries can still be preserved,
as long as it's coerced to the right width (done by coerce_reg_to_size).
Even further, if the actual value fits into the fill width, the ID can
be preserved as well for further tracking of equal scalars.
Implement the above improvements, which makes narrowing fills behave the
same as narrowing spills and MOVs between registers.
Two tests are adjusted to accommodate for endianness differences and to
take into account that it's now allowed to do a narrowing fill from the
least significant bits.
reg_bounds_sync is added to coerce_reg_to_size to correctly adjust
umin/umax boundaries after the var_off truncation, for example, a 64-bit
value 0xXXXXXXXX00000000, when read as a 32-bit, gets umin = 0, umax =
0xFFFFFFFF, var_off = (0x0; 0xffffffff00000000), which needs to be
synced down to umax = 0, otherwise reg_bounds_sanity_check doesn't pass.
Signed-off-by: Maxim Mikityanskiy <maxim@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240127175237.526726-4-maxtram95@gmail.com
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The previous commit added tracking for unbounded scalars on spill. Add
the test case to check the new functionality.
Signed-off-by: Maxim Mikityanskiy <maxim@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20240127175237.526726-3-maxtram95@gmail.com
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Support the pattern where an unbounded scalar is spilled to the stack,
then boundary checks are performed on the src register, after which the
stack frame slot is refilled into a register.
Before this commit, the verifier didn't treat the src register and the
stack slot as related if the src register was an unbounded scalar. The
register state wasn't copied, the id wasn't preserved, and the stack
slot was marked as STACK_MISC. Subsequent boundary checks on the src
register wouldn't result in updating the boundaries of the spilled
variable on the stack.
After this commit, the verifier will preserve the bond between src and
dst even if src is unbounded, which permits to do boundary checks on src
and refill dst later, still remembering its boundaries. Such a pattern
is sometimes generated by clang when compiling complex long functions.
One test is adjusted to reflect that now unbounded scalars are tracked.
Signed-off-by: Maxim Mikityanskiy <maxim@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20240127175237.526726-2-maxtram95@gmail.com
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Use more ergonomic bpf_core_cast() macro instead of bpf_rdonly_cast() in
selftests code.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240130212023.183765-3-andrii@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
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Add bpf_core_cast() macro that wraps bpf_rdonly_cast() kfunc. It's more
ergonomic than kfunc, as it automatically extracts btf_id with
bpf_core_type_id_kernel(), and works with type names. It also casts result
to (T *) pointer. See the definition of the macro, it's self-explanatory.
libbpf declares bpf_rdonly_cast() extern as __weak __ksym and should be
safe to not conflict with other possible declarations in user code.
But we do have a conflict with current BPF selftests that declare their
externs with first argument as `void *obj`, while libbpf opts into more
permissive `const void *obj`. This causes conflict, so we fix up BPF
selftests uses in the same patch.
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240130212023.183765-2-andrii@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
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Add a bunch of test cases validating behavior of __arg_trusted and its
combination with __arg_nullable tag. We also validate CO-RE flavor
support by kernel for __arg_trusted args.
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240130000648.2144827-5-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Add tests for LSM interactions (both bpf_token_capable and bpf_token_cmd
LSM hooks) with BPF token in bpf() subsystem. Now child process passes
back token FD for parent to be able to do tests with token originating
in "wrong" userns. But we also create token in initns and check that
token LSMs don't accidentally reject BPF operations when capable()
checks pass without BPF token.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20240124022127.2379740-31-andrii@kernel.org
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