2024-04-05 16:11:34 -07:00
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// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */
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#include <linux/bpf.h>
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#include <bpf/bpf_helpers.h>
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#include <bpf/bpf_tracing.h>
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#include <stdbool.h>
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selftests/bpf: Fix arena_atomics failure due to llvm change
llvm change [1] made a change such that __sync_fetch_and_{and,or,xor}()
will generate atomic_fetch_*() insns even if the return value is not used.
This is a deliberate choice to make sure barrier semantics are preserved
from source code to asm insn.
But the change in [1] caused arena_atomics selftest failure.
test_arena_atomics:PASS:arena atomics skeleton open 0 nsec
libbpf: prog 'and': BPF program load failed: Permission denied
libbpf: prog 'and': -- BEGIN PROG LOAD LOG --
arg#0 reference type('UNKNOWN ') size cannot be determined: -22
0: R1=ctx() R10=fp0
; if (pid != (bpf_get_current_pid_tgid() >> 32)) @ arena_atomics.c:87
0: (18) r1 = 0xffffc90000064000 ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4)
2: (61) r6 = *(u32 *)(r1 +0) ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4) R6_w=scalar(smin=0,smax=umax=0xffffffff,v
ar_off=(0x0; 0xffffffff))
3: (85) call bpf_get_current_pid_tgid#14 ; R0_w=scalar()
4: (77) r0 >>= 32 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff))
5: (5d) if r0 != r6 goto pc+11 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) R6_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0x)
; __sync_fetch_and_and(&and64_value, 0x011ull << 32); @ arena_atomics.c:91
6: (18) r1 = 0x100000000060 ; R1_w=scalar()
8: (bf) r1 = addr_space_cast(r1, 0, 1) ; R1_w=arena
9: (18) r2 = 0x1100000000 ; R2_w=0x1100000000
11: (db) r2 = atomic64_fetch_and((u64 *)(r1 +0), r2)
BPF_ATOMIC stores into R1 arena is not allowed
processed 9 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0
-- END PROG LOAD LOG --
libbpf: prog 'and': failed to load: -13
libbpf: failed to load object 'arena_atomics'
libbpf: failed to load BPF skeleton 'arena_atomics': -13
test_arena_atomics:FAIL:arena atomics skeleton load unexpected error: -13 (errno 13)
#3 arena_atomics:FAIL
The reason of the failure is due to [2] where atomic{64,}_fetch_{and,or,xor}() are not
allowed by arena addresses.
Version 2 of the patch fixed the issue by using inline asm ([3]). But further discussion
suggested to find a way from source to generate locked insn which is more user
friendly. So in not-merged llvm patch ([4]), if relax memory ordering is used and
the return value is not used, locked insn could be generated.
So with llvm patch [4] to compile the bpf selftest, the following code
__c11_atomic_fetch_and(&and64_value, 0x011ull << 32, memory_order_relaxed);
is able to generate locked insn, hence fixing the selftest failure.
[1] https://github.com/llvm/llvm-project/pull/106494
[2] d503a04f8bc0 ("bpf: Add support for certain atomics in bpf_arena to x86 JIT")
[3] https://lore.kernel.org/bpf/20240803025928.4184433-1-yonghong.song@linux.dev/
[4] https://github.com/llvm/llvm-project/pull/107343
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240909223431.1666305-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-09 15:34:31 -07:00
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#include <stdatomic.h>
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2024-04-05 16:11:34 -07:00
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#include "bpf_arena_common.h"
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selftests/bpf: Add selftests for load-acquire and store-release instructions
Add several ./test_progs tests:
- arena_atomics/load_acquire
- arena_atomics/store_release
- verifier_load_acquire/*
- verifier_store_release/*
- verifier_precision/bpf_load_acquire
- verifier_precision/bpf_store_release
The last two tests are added to check if backtrack_insn() handles the
new instructions correctly.
Additionally, the last test also makes sure that the verifier
"remembers" the value (in src_reg) we store-release into e.g. a stack
slot. For example, if we take a look at the test program:
#0: r1 = 8;
/* store_release((u64 *)(r10 - 8), r1); */
#1: .8byte %[store_release];
#2: r1 = *(u64 *)(r10 - 8);
#3: r2 = r10;
#4: r2 += r1;
#5: r0 = 0;
#6: exit;
At #1, if the verifier doesn't remember that we wrote 8 to the stack,
then later at #4 we would be adding an unbounded scalar value to the
stack pointer, which would cause the program to be rejected:
VERIFIER LOG:
=============
...
math between fp pointer and register with unbounded min value is not allowed
For easier CI integration, instead of using built-ins like
__atomic_{load,store}_n() which depend on the new
__BPF_FEATURE_LOAD_ACQ_STORE_REL pre-defined macro, manually craft
load-acquire/store-release instructions using __imm_insn(), as suggested
by Eduard.
All new tests depend on:
(1) Clang major version >= 18, and
(2) ENABLE_ATOMICS_TESTS is defined (currently implies -mcpu=v3 or
v4), and
(3) JIT supports load-acquire/store-release (currently arm64 and
x86-64)
In .../progs/arena_atomics.c:
/* 8-byte-aligned */
__u8 __arena_global load_acquire8_value = 0x12;
/* 1-byte hole */
__u16 __arena_global load_acquire16_value = 0x1234;
That 1-byte hole in the .addr_space.1 ELF section caused clang-17 to
crash:
fatal error: error in backend: unable to write nop sequence of 1 bytes
To work around such llvm-17 CI job failures, conditionally define
__arena_global variables as 64-bit if __clang_major__ < 18, to make sure
.addr_space.1 has no holes. Ideally we should avoid compiling this file
using clang-17 at all (arena tests depend on
__BPF_FEATURE_ADDR_SPACE_CAST, and are skipped for llvm-17 anyway), but
that is a separate topic.
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Peilin Ye <yepeilin@google.com>
Link: https://lore.kernel.org/r/1b46c6feaf0f1b6984d9ec80e500cc7383e9da1a.1741049567.git.yepeilin@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-03-04 01:06:46 +00:00
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#include "../../../include/linux/filter.h"
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#include "bpf_misc.h"
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2024-04-05 16:11:34 -07:00
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struct {
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__uint(type, BPF_MAP_TYPE_ARENA);
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__uint(map_flags, BPF_F_MMAPABLE);
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__uint(max_entries, 10); /* number of pages */
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#ifdef __TARGET_ARCH_arm64
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__ulong(map_extra, 0x1ull << 32); /* start of mmap() region */
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#else
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__ulong(map_extra, 0x1ull << 44); /* start of mmap() region */
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#endif
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} arena SEC(".maps");
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#if defined(ENABLE_ATOMICS_TESTS) && defined(__BPF_FEATURE_ADDR_SPACE_CAST)
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selftests/bpf: Add selftests for load-acquire and store-release instructions
Add several ./test_progs tests:
- arena_atomics/load_acquire
- arena_atomics/store_release
- verifier_load_acquire/*
- verifier_store_release/*
- verifier_precision/bpf_load_acquire
- verifier_precision/bpf_store_release
The last two tests are added to check if backtrack_insn() handles the
new instructions correctly.
Additionally, the last test also makes sure that the verifier
"remembers" the value (in src_reg) we store-release into e.g. a stack
slot. For example, if we take a look at the test program:
#0: r1 = 8;
/* store_release((u64 *)(r10 - 8), r1); */
#1: .8byte %[store_release];
#2: r1 = *(u64 *)(r10 - 8);
#3: r2 = r10;
#4: r2 += r1;
#5: r0 = 0;
#6: exit;
At #1, if the verifier doesn't remember that we wrote 8 to the stack,
then later at #4 we would be adding an unbounded scalar value to the
stack pointer, which would cause the program to be rejected:
VERIFIER LOG:
=============
...
math between fp pointer and register with unbounded min value is not allowed
For easier CI integration, instead of using built-ins like
__atomic_{load,store}_n() which depend on the new
__BPF_FEATURE_LOAD_ACQ_STORE_REL pre-defined macro, manually craft
load-acquire/store-release instructions using __imm_insn(), as suggested
by Eduard.
All new tests depend on:
(1) Clang major version >= 18, and
(2) ENABLE_ATOMICS_TESTS is defined (currently implies -mcpu=v3 or
v4), and
(3) JIT supports load-acquire/store-release (currently arm64 and
x86-64)
In .../progs/arena_atomics.c:
/* 8-byte-aligned */
__u8 __arena_global load_acquire8_value = 0x12;
/* 1-byte hole */
__u16 __arena_global load_acquire16_value = 0x1234;
That 1-byte hole in the .addr_space.1 ELF section caused clang-17 to
crash:
fatal error: error in backend: unable to write nop sequence of 1 bytes
To work around such llvm-17 CI job failures, conditionally define
__arena_global variables as 64-bit if __clang_major__ < 18, to make sure
.addr_space.1 has no holes. Ideally we should avoid compiling this file
using clang-17 at all (arena tests depend on
__BPF_FEATURE_ADDR_SPACE_CAST, and are skipped for llvm-17 anyway), but
that is a separate topic.
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Peilin Ye <yepeilin@google.com>
Link: https://lore.kernel.org/r/1b46c6feaf0f1b6984d9ec80e500cc7383e9da1a.1741049567.git.yepeilin@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-03-04 01:06:46 +00:00
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bool skip_all_tests __attribute((__section__(".data"))) = false;
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2024-04-05 16:11:34 -07:00
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#else
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selftests/bpf: Add selftests for load-acquire and store-release instructions
Add several ./test_progs tests:
- arena_atomics/load_acquire
- arena_atomics/store_release
- verifier_load_acquire/*
- verifier_store_release/*
- verifier_precision/bpf_load_acquire
- verifier_precision/bpf_store_release
The last two tests are added to check if backtrack_insn() handles the
new instructions correctly.
Additionally, the last test also makes sure that the verifier
"remembers" the value (in src_reg) we store-release into e.g. a stack
slot. For example, if we take a look at the test program:
#0: r1 = 8;
/* store_release((u64 *)(r10 - 8), r1); */
#1: .8byte %[store_release];
#2: r1 = *(u64 *)(r10 - 8);
#3: r2 = r10;
#4: r2 += r1;
#5: r0 = 0;
#6: exit;
At #1, if the verifier doesn't remember that we wrote 8 to the stack,
then later at #4 we would be adding an unbounded scalar value to the
stack pointer, which would cause the program to be rejected:
VERIFIER LOG:
=============
...
math between fp pointer and register with unbounded min value is not allowed
For easier CI integration, instead of using built-ins like
__atomic_{load,store}_n() which depend on the new
__BPF_FEATURE_LOAD_ACQ_STORE_REL pre-defined macro, manually craft
load-acquire/store-release instructions using __imm_insn(), as suggested
by Eduard.
All new tests depend on:
(1) Clang major version >= 18, and
(2) ENABLE_ATOMICS_TESTS is defined (currently implies -mcpu=v3 or
v4), and
(3) JIT supports load-acquire/store-release (currently arm64 and
x86-64)
In .../progs/arena_atomics.c:
/* 8-byte-aligned */
__u8 __arena_global load_acquire8_value = 0x12;
/* 1-byte hole */
__u16 __arena_global load_acquire16_value = 0x1234;
That 1-byte hole in the .addr_space.1 ELF section caused clang-17 to
crash:
fatal error: error in backend: unable to write nop sequence of 1 bytes
To work around such llvm-17 CI job failures, conditionally define
__arena_global variables as 64-bit if __clang_major__ < 18, to make sure
.addr_space.1 has no holes. Ideally we should avoid compiling this file
using clang-17 at all (arena tests depend on
__BPF_FEATURE_ADDR_SPACE_CAST, and are skipped for llvm-17 anyway), but
that is a separate topic.
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Peilin Ye <yepeilin@google.com>
Link: https://lore.kernel.org/r/1b46c6feaf0f1b6984d9ec80e500cc7383e9da1a.1741049567.git.yepeilin@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-03-04 01:06:46 +00:00
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bool skip_all_tests = true;
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#endif
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#if defined(ENABLE_ATOMICS_TESTS) && \
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defined(__BPF_FEATURE_ADDR_SPACE_CAST) && \
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(defined(__TARGET_ARCH_arm64) || defined(__TARGET_ARCH_x86))
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bool skip_lacq_srel_tests __attribute((__section__(".data"))) = false;
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#else
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bool skip_lacq_srel_tests = true;
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2024-04-05 16:11:34 -07:00
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#endif
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__u32 pid = 0;
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2024-07-02 01:40:28 +02:00
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__u64 __arena_global add64_value = 1;
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__u64 __arena_global add64_result = 0;
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__u32 __arena_global add32_value = 1;
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__u32 __arena_global add32_result = 0;
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__u64 __arena_global add_stack_value_copy = 0;
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__u64 __arena_global add_stack_result = 0;
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__u64 __arena_global add_noreturn_value = 1;
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2024-04-05 16:11:34 -07:00
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SEC("raw_tp/sys_enter")
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int add(const void *ctx)
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{
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if (pid != (bpf_get_current_pid_tgid() >> 32))
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return 0;
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#ifdef ENABLE_ATOMICS_TESTS
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__u64 add_stack_value = 1;
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add64_result = __sync_fetch_and_add(&add64_value, 2);
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add32_result = __sync_fetch_and_add(&add32_value, 2);
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add_stack_result = __sync_fetch_and_add(&add_stack_value, 2);
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add_stack_value_copy = add_stack_value;
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__sync_fetch_and_add(&add_noreturn_value, 2);
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#endif
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return 0;
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}
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2024-07-02 01:40:28 +02:00
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__s64 __arena_global sub64_value = 1;
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__s64 __arena_global sub64_result = 0;
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__s32 __arena_global sub32_value = 1;
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__s32 __arena_global sub32_result = 0;
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__s64 __arena_global sub_stack_value_copy = 0;
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__s64 __arena_global sub_stack_result = 0;
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__s64 __arena_global sub_noreturn_value = 1;
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2024-04-05 16:11:34 -07:00
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SEC("raw_tp/sys_enter")
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int sub(const void *ctx)
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{
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if (pid != (bpf_get_current_pid_tgid() >> 32))
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return 0;
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#ifdef ENABLE_ATOMICS_TESTS
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__u64 sub_stack_value = 1;
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sub64_result = __sync_fetch_and_sub(&sub64_value, 2);
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sub32_result = __sync_fetch_and_sub(&sub32_value, 2);
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sub_stack_result = __sync_fetch_and_sub(&sub_stack_value, 2);
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sub_stack_value_copy = sub_stack_value;
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__sync_fetch_and_sub(&sub_noreturn_value, 2);
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#endif
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return 0;
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}
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selftests/bpf: Fix arena_atomics failure due to llvm change
llvm change [1] made a change such that __sync_fetch_and_{and,or,xor}()
will generate atomic_fetch_*() insns even if the return value is not used.
This is a deliberate choice to make sure barrier semantics are preserved
from source code to asm insn.
But the change in [1] caused arena_atomics selftest failure.
test_arena_atomics:PASS:arena atomics skeleton open 0 nsec
libbpf: prog 'and': BPF program load failed: Permission denied
libbpf: prog 'and': -- BEGIN PROG LOAD LOG --
arg#0 reference type('UNKNOWN ') size cannot be determined: -22
0: R1=ctx() R10=fp0
; if (pid != (bpf_get_current_pid_tgid() >> 32)) @ arena_atomics.c:87
0: (18) r1 = 0xffffc90000064000 ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4)
2: (61) r6 = *(u32 *)(r1 +0) ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4) R6_w=scalar(smin=0,smax=umax=0xffffffff,v
ar_off=(0x0; 0xffffffff))
3: (85) call bpf_get_current_pid_tgid#14 ; R0_w=scalar()
4: (77) r0 >>= 32 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff))
5: (5d) if r0 != r6 goto pc+11 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) R6_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0x)
; __sync_fetch_and_and(&and64_value, 0x011ull << 32); @ arena_atomics.c:91
6: (18) r1 = 0x100000000060 ; R1_w=scalar()
8: (bf) r1 = addr_space_cast(r1, 0, 1) ; R1_w=arena
9: (18) r2 = 0x1100000000 ; R2_w=0x1100000000
11: (db) r2 = atomic64_fetch_and((u64 *)(r1 +0), r2)
BPF_ATOMIC stores into R1 arena is not allowed
processed 9 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0
-- END PROG LOAD LOG --
libbpf: prog 'and': failed to load: -13
libbpf: failed to load object 'arena_atomics'
libbpf: failed to load BPF skeleton 'arena_atomics': -13
test_arena_atomics:FAIL:arena atomics skeleton load unexpected error: -13 (errno 13)
#3 arena_atomics:FAIL
The reason of the failure is due to [2] where atomic{64,}_fetch_{and,or,xor}() are not
allowed by arena addresses.
Version 2 of the patch fixed the issue by using inline asm ([3]). But further discussion
suggested to find a way from source to generate locked insn which is more user
friendly. So in not-merged llvm patch ([4]), if relax memory ordering is used and
the return value is not used, locked insn could be generated.
So with llvm patch [4] to compile the bpf selftest, the following code
__c11_atomic_fetch_and(&and64_value, 0x011ull << 32, memory_order_relaxed);
is able to generate locked insn, hence fixing the selftest failure.
[1] https://github.com/llvm/llvm-project/pull/106494
[2] d503a04f8bc0 ("bpf: Add support for certain atomics in bpf_arena to x86 JIT")
[3] https://lore.kernel.org/bpf/20240803025928.4184433-1-yonghong.song@linux.dev/
[4] https://github.com/llvm/llvm-project/pull/107343
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240909223431.1666305-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-09 15:34:31 -07:00
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#ifdef __BPF_FEATURE_ATOMIC_MEM_ORDERING
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_Atomic __u64 __arena_global and64_value = (0x110ull << 32);
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_Atomic __u32 __arena_global and32_value = 0x110;
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#else
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2024-07-02 01:40:28 +02:00
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__u64 __arena_global and64_value = (0x110ull << 32);
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__u32 __arena_global and32_value = 0x110;
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selftests/bpf: Fix arena_atomics failure due to llvm change
llvm change [1] made a change such that __sync_fetch_and_{and,or,xor}()
will generate atomic_fetch_*() insns even if the return value is not used.
This is a deliberate choice to make sure barrier semantics are preserved
from source code to asm insn.
But the change in [1] caused arena_atomics selftest failure.
test_arena_atomics:PASS:arena atomics skeleton open 0 nsec
libbpf: prog 'and': BPF program load failed: Permission denied
libbpf: prog 'and': -- BEGIN PROG LOAD LOG --
arg#0 reference type('UNKNOWN ') size cannot be determined: -22
0: R1=ctx() R10=fp0
; if (pid != (bpf_get_current_pid_tgid() >> 32)) @ arena_atomics.c:87
0: (18) r1 = 0xffffc90000064000 ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4)
2: (61) r6 = *(u32 *)(r1 +0) ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4) R6_w=scalar(smin=0,smax=umax=0xffffffff,v
ar_off=(0x0; 0xffffffff))
3: (85) call bpf_get_current_pid_tgid#14 ; R0_w=scalar()
4: (77) r0 >>= 32 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff))
5: (5d) if r0 != r6 goto pc+11 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) R6_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0x)
; __sync_fetch_and_and(&and64_value, 0x011ull << 32); @ arena_atomics.c:91
6: (18) r1 = 0x100000000060 ; R1_w=scalar()
8: (bf) r1 = addr_space_cast(r1, 0, 1) ; R1_w=arena
9: (18) r2 = 0x1100000000 ; R2_w=0x1100000000
11: (db) r2 = atomic64_fetch_and((u64 *)(r1 +0), r2)
BPF_ATOMIC stores into R1 arena is not allowed
processed 9 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0
-- END PROG LOAD LOG --
libbpf: prog 'and': failed to load: -13
libbpf: failed to load object 'arena_atomics'
libbpf: failed to load BPF skeleton 'arena_atomics': -13
test_arena_atomics:FAIL:arena atomics skeleton load unexpected error: -13 (errno 13)
#3 arena_atomics:FAIL
The reason of the failure is due to [2] where atomic{64,}_fetch_{and,or,xor}() are not
allowed by arena addresses.
Version 2 of the patch fixed the issue by using inline asm ([3]). But further discussion
suggested to find a way from source to generate locked insn which is more user
friendly. So in not-merged llvm patch ([4]), if relax memory ordering is used and
the return value is not used, locked insn could be generated.
So with llvm patch [4] to compile the bpf selftest, the following code
__c11_atomic_fetch_and(&and64_value, 0x011ull << 32, memory_order_relaxed);
is able to generate locked insn, hence fixing the selftest failure.
[1] https://github.com/llvm/llvm-project/pull/106494
[2] d503a04f8bc0 ("bpf: Add support for certain atomics in bpf_arena to x86 JIT")
[3] https://lore.kernel.org/bpf/20240803025928.4184433-1-yonghong.song@linux.dev/
[4] https://github.com/llvm/llvm-project/pull/107343
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240909223431.1666305-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-09 15:34:31 -07:00
|
|
|
#endif
|
2024-04-05 16:11:34 -07:00
|
|
|
|
|
|
|
SEC("raw_tp/sys_enter")
|
|
|
|
int and(const void *ctx)
|
|
|
|
{
|
|
|
|
if (pid != (bpf_get_current_pid_tgid() >> 32))
|
|
|
|
return 0;
|
|
|
|
#ifdef ENABLE_ATOMICS_TESTS
|
selftests/bpf: Fix arena_atomics failure due to llvm change
llvm change [1] made a change such that __sync_fetch_and_{and,or,xor}()
will generate atomic_fetch_*() insns even if the return value is not used.
This is a deliberate choice to make sure barrier semantics are preserved
from source code to asm insn.
But the change in [1] caused arena_atomics selftest failure.
test_arena_atomics:PASS:arena atomics skeleton open 0 nsec
libbpf: prog 'and': BPF program load failed: Permission denied
libbpf: prog 'and': -- BEGIN PROG LOAD LOG --
arg#0 reference type('UNKNOWN ') size cannot be determined: -22
0: R1=ctx() R10=fp0
; if (pid != (bpf_get_current_pid_tgid() >> 32)) @ arena_atomics.c:87
0: (18) r1 = 0xffffc90000064000 ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4)
2: (61) r6 = *(u32 *)(r1 +0) ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4) R6_w=scalar(smin=0,smax=umax=0xffffffff,v
ar_off=(0x0; 0xffffffff))
3: (85) call bpf_get_current_pid_tgid#14 ; R0_w=scalar()
4: (77) r0 >>= 32 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff))
5: (5d) if r0 != r6 goto pc+11 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) R6_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0x)
; __sync_fetch_and_and(&and64_value, 0x011ull << 32); @ arena_atomics.c:91
6: (18) r1 = 0x100000000060 ; R1_w=scalar()
8: (bf) r1 = addr_space_cast(r1, 0, 1) ; R1_w=arena
9: (18) r2 = 0x1100000000 ; R2_w=0x1100000000
11: (db) r2 = atomic64_fetch_and((u64 *)(r1 +0), r2)
BPF_ATOMIC stores into R1 arena is not allowed
processed 9 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0
-- END PROG LOAD LOG --
libbpf: prog 'and': failed to load: -13
libbpf: failed to load object 'arena_atomics'
libbpf: failed to load BPF skeleton 'arena_atomics': -13
test_arena_atomics:FAIL:arena atomics skeleton load unexpected error: -13 (errno 13)
#3 arena_atomics:FAIL
The reason of the failure is due to [2] where atomic{64,}_fetch_{and,or,xor}() are not
allowed by arena addresses.
Version 2 of the patch fixed the issue by using inline asm ([3]). But further discussion
suggested to find a way from source to generate locked insn which is more user
friendly. So in not-merged llvm patch ([4]), if relax memory ordering is used and
the return value is not used, locked insn could be generated.
So with llvm patch [4] to compile the bpf selftest, the following code
__c11_atomic_fetch_and(&and64_value, 0x011ull << 32, memory_order_relaxed);
is able to generate locked insn, hence fixing the selftest failure.
[1] https://github.com/llvm/llvm-project/pull/106494
[2] d503a04f8bc0 ("bpf: Add support for certain atomics in bpf_arena to x86 JIT")
[3] https://lore.kernel.org/bpf/20240803025928.4184433-1-yonghong.song@linux.dev/
[4] https://github.com/llvm/llvm-project/pull/107343
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240909223431.1666305-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-09 15:34:31 -07:00
|
|
|
#ifdef __BPF_FEATURE_ATOMIC_MEM_ORDERING
|
|
|
|
__c11_atomic_fetch_and(&and64_value, 0x011ull << 32, memory_order_relaxed);
|
|
|
|
__c11_atomic_fetch_and(&and32_value, 0x011, memory_order_relaxed);
|
|
|
|
#else
|
2024-04-05 16:11:34 -07:00
|
|
|
__sync_fetch_and_and(&and64_value, 0x011ull << 32);
|
|
|
|
__sync_fetch_and_and(&and32_value, 0x011);
|
selftests/bpf: Fix arena_atomics failure due to llvm change
llvm change [1] made a change such that __sync_fetch_and_{and,or,xor}()
will generate atomic_fetch_*() insns even if the return value is not used.
This is a deliberate choice to make sure barrier semantics are preserved
from source code to asm insn.
But the change in [1] caused arena_atomics selftest failure.
test_arena_atomics:PASS:arena atomics skeleton open 0 nsec
libbpf: prog 'and': BPF program load failed: Permission denied
libbpf: prog 'and': -- BEGIN PROG LOAD LOG --
arg#0 reference type('UNKNOWN ') size cannot be determined: -22
0: R1=ctx() R10=fp0
; if (pid != (bpf_get_current_pid_tgid() >> 32)) @ arena_atomics.c:87
0: (18) r1 = 0xffffc90000064000 ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4)
2: (61) r6 = *(u32 *)(r1 +0) ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4) R6_w=scalar(smin=0,smax=umax=0xffffffff,v
ar_off=(0x0; 0xffffffff))
3: (85) call bpf_get_current_pid_tgid#14 ; R0_w=scalar()
4: (77) r0 >>= 32 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff))
5: (5d) if r0 != r6 goto pc+11 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) R6_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0x)
; __sync_fetch_and_and(&and64_value, 0x011ull << 32); @ arena_atomics.c:91
6: (18) r1 = 0x100000000060 ; R1_w=scalar()
8: (bf) r1 = addr_space_cast(r1, 0, 1) ; R1_w=arena
9: (18) r2 = 0x1100000000 ; R2_w=0x1100000000
11: (db) r2 = atomic64_fetch_and((u64 *)(r1 +0), r2)
BPF_ATOMIC stores into R1 arena is not allowed
processed 9 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0
-- END PROG LOAD LOG --
libbpf: prog 'and': failed to load: -13
libbpf: failed to load object 'arena_atomics'
libbpf: failed to load BPF skeleton 'arena_atomics': -13
test_arena_atomics:FAIL:arena atomics skeleton load unexpected error: -13 (errno 13)
#3 arena_atomics:FAIL
The reason of the failure is due to [2] where atomic{64,}_fetch_{and,or,xor}() are not
allowed by arena addresses.
Version 2 of the patch fixed the issue by using inline asm ([3]). But further discussion
suggested to find a way from source to generate locked insn which is more user
friendly. So in not-merged llvm patch ([4]), if relax memory ordering is used and
the return value is not used, locked insn could be generated.
So with llvm patch [4] to compile the bpf selftest, the following code
__c11_atomic_fetch_and(&and64_value, 0x011ull << 32, memory_order_relaxed);
is able to generate locked insn, hence fixing the selftest failure.
[1] https://github.com/llvm/llvm-project/pull/106494
[2] d503a04f8bc0 ("bpf: Add support for certain atomics in bpf_arena to x86 JIT")
[3] https://lore.kernel.org/bpf/20240803025928.4184433-1-yonghong.song@linux.dev/
[4] https://github.com/llvm/llvm-project/pull/107343
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240909223431.1666305-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-09 15:34:31 -07:00
|
|
|
#endif
|
2024-04-05 16:11:34 -07:00
|
|
|
#endif
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
selftests/bpf: Fix arena_atomics failure due to llvm change
llvm change [1] made a change such that __sync_fetch_and_{and,or,xor}()
will generate atomic_fetch_*() insns even if the return value is not used.
This is a deliberate choice to make sure barrier semantics are preserved
from source code to asm insn.
But the change in [1] caused arena_atomics selftest failure.
test_arena_atomics:PASS:arena atomics skeleton open 0 nsec
libbpf: prog 'and': BPF program load failed: Permission denied
libbpf: prog 'and': -- BEGIN PROG LOAD LOG --
arg#0 reference type('UNKNOWN ') size cannot be determined: -22
0: R1=ctx() R10=fp0
; if (pid != (bpf_get_current_pid_tgid() >> 32)) @ arena_atomics.c:87
0: (18) r1 = 0xffffc90000064000 ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4)
2: (61) r6 = *(u32 *)(r1 +0) ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4) R6_w=scalar(smin=0,smax=umax=0xffffffff,v
ar_off=(0x0; 0xffffffff))
3: (85) call bpf_get_current_pid_tgid#14 ; R0_w=scalar()
4: (77) r0 >>= 32 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff))
5: (5d) if r0 != r6 goto pc+11 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) R6_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0x)
; __sync_fetch_and_and(&and64_value, 0x011ull << 32); @ arena_atomics.c:91
6: (18) r1 = 0x100000000060 ; R1_w=scalar()
8: (bf) r1 = addr_space_cast(r1, 0, 1) ; R1_w=arena
9: (18) r2 = 0x1100000000 ; R2_w=0x1100000000
11: (db) r2 = atomic64_fetch_and((u64 *)(r1 +0), r2)
BPF_ATOMIC stores into R1 arena is not allowed
processed 9 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0
-- END PROG LOAD LOG --
libbpf: prog 'and': failed to load: -13
libbpf: failed to load object 'arena_atomics'
libbpf: failed to load BPF skeleton 'arena_atomics': -13
test_arena_atomics:FAIL:arena atomics skeleton load unexpected error: -13 (errno 13)
#3 arena_atomics:FAIL
The reason of the failure is due to [2] where atomic{64,}_fetch_{and,or,xor}() are not
allowed by arena addresses.
Version 2 of the patch fixed the issue by using inline asm ([3]). But further discussion
suggested to find a way from source to generate locked insn which is more user
friendly. So in not-merged llvm patch ([4]), if relax memory ordering is used and
the return value is not used, locked insn could be generated.
So with llvm patch [4] to compile the bpf selftest, the following code
__c11_atomic_fetch_and(&and64_value, 0x011ull << 32, memory_order_relaxed);
is able to generate locked insn, hence fixing the selftest failure.
[1] https://github.com/llvm/llvm-project/pull/106494
[2] d503a04f8bc0 ("bpf: Add support for certain atomics in bpf_arena to x86 JIT")
[3] https://lore.kernel.org/bpf/20240803025928.4184433-1-yonghong.song@linux.dev/
[4] https://github.com/llvm/llvm-project/pull/107343
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240909223431.1666305-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-09 15:34:31 -07:00
|
|
|
#ifdef __BPF_FEATURE_ATOMIC_MEM_ORDERING
|
|
|
|
_Atomic __u32 __arena_global or32_value = 0x110;
|
|
|
|
_Atomic __u64 __arena_global or64_value = (0x110ull << 32);
|
|
|
|
#else
|
2024-07-02 01:40:28 +02:00
|
|
|
__u32 __arena_global or32_value = 0x110;
|
|
|
|
__u64 __arena_global or64_value = (0x110ull << 32);
|
selftests/bpf: Fix arena_atomics failure due to llvm change
llvm change [1] made a change such that __sync_fetch_and_{and,or,xor}()
will generate atomic_fetch_*() insns even if the return value is not used.
This is a deliberate choice to make sure barrier semantics are preserved
from source code to asm insn.
But the change in [1] caused arena_atomics selftest failure.
test_arena_atomics:PASS:arena atomics skeleton open 0 nsec
libbpf: prog 'and': BPF program load failed: Permission denied
libbpf: prog 'and': -- BEGIN PROG LOAD LOG --
arg#0 reference type('UNKNOWN ') size cannot be determined: -22
0: R1=ctx() R10=fp0
; if (pid != (bpf_get_current_pid_tgid() >> 32)) @ arena_atomics.c:87
0: (18) r1 = 0xffffc90000064000 ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4)
2: (61) r6 = *(u32 *)(r1 +0) ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4) R6_w=scalar(smin=0,smax=umax=0xffffffff,v
ar_off=(0x0; 0xffffffff))
3: (85) call bpf_get_current_pid_tgid#14 ; R0_w=scalar()
4: (77) r0 >>= 32 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff))
5: (5d) if r0 != r6 goto pc+11 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) R6_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0x)
; __sync_fetch_and_and(&and64_value, 0x011ull << 32); @ arena_atomics.c:91
6: (18) r1 = 0x100000000060 ; R1_w=scalar()
8: (bf) r1 = addr_space_cast(r1, 0, 1) ; R1_w=arena
9: (18) r2 = 0x1100000000 ; R2_w=0x1100000000
11: (db) r2 = atomic64_fetch_and((u64 *)(r1 +0), r2)
BPF_ATOMIC stores into R1 arena is not allowed
processed 9 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0
-- END PROG LOAD LOG --
libbpf: prog 'and': failed to load: -13
libbpf: failed to load object 'arena_atomics'
libbpf: failed to load BPF skeleton 'arena_atomics': -13
test_arena_atomics:FAIL:arena atomics skeleton load unexpected error: -13 (errno 13)
#3 arena_atomics:FAIL
The reason of the failure is due to [2] where atomic{64,}_fetch_{and,or,xor}() are not
allowed by arena addresses.
Version 2 of the patch fixed the issue by using inline asm ([3]). But further discussion
suggested to find a way from source to generate locked insn which is more user
friendly. So in not-merged llvm patch ([4]), if relax memory ordering is used and
the return value is not used, locked insn could be generated.
So with llvm patch [4] to compile the bpf selftest, the following code
__c11_atomic_fetch_and(&and64_value, 0x011ull << 32, memory_order_relaxed);
is able to generate locked insn, hence fixing the selftest failure.
[1] https://github.com/llvm/llvm-project/pull/106494
[2] d503a04f8bc0 ("bpf: Add support for certain atomics in bpf_arena to x86 JIT")
[3] https://lore.kernel.org/bpf/20240803025928.4184433-1-yonghong.song@linux.dev/
[4] https://github.com/llvm/llvm-project/pull/107343
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240909223431.1666305-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-09 15:34:31 -07:00
|
|
|
#endif
|
2024-04-05 16:11:34 -07:00
|
|
|
|
|
|
|
SEC("raw_tp/sys_enter")
|
|
|
|
int or(const void *ctx)
|
|
|
|
{
|
|
|
|
if (pid != (bpf_get_current_pid_tgid() >> 32))
|
|
|
|
return 0;
|
|
|
|
#ifdef ENABLE_ATOMICS_TESTS
|
selftests/bpf: Fix arena_atomics failure due to llvm change
llvm change [1] made a change such that __sync_fetch_and_{and,or,xor}()
will generate atomic_fetch_*() insns even if the return value is not used.
This is a deliberate choice to make sure barrier semantics are preserved
from source code to asm insn.
But the change in [1] caused arena_atomics selftest failure.
test_arena_atomics:PASS:arena atomics skeleton open 0 nsec
libbpf: prog 'and': BPF program load failed: Permission denied
libbpf: prog 'and': -- BEGIN PROG LOAD LOG --
arg#0 reference type('UNKNOWN ') size cannot be determined: -22
0: R1=ctx() R10=fp0
; if (pid != (bpf_get_current_pid_tgid() >> 32)) @ arena_atomics.c:87
0: (18) r1 = 0xffffc90000064000 ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4)
2: (61) r6 = *(u32 *)(r1 +0) ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4) R6_w=scalar(smin=0,smax=umax=0xffffffff,v
ar_off=(0x0; 0xffffffff))
3: (85) call bpf_get_current_pid_tgid#14 ; R0_w=scalar()
4: (77) r0 >>= 32 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff))
5: (5d) if r0 != r6 goto pc+11 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) R6_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0x)
; __sync_fetch_and_and(&and64_value, 0x011ull << 32); @ arena_atomics.c:91
6: (18) r1 = 0x100000000060 ; R1_w=scalar()
8: (bf) r1 = addr_space_cast(r1, 0, 1) ; R1_w=arena
9: (18) r2 = 0x1100000000 ; R2_w=0x1100000000
11: (db) r2 = atomic64_fetch_and((u64 *)(r1 +0), r2)
BPF_ATOMIC stores into R1 arena is not allowed
processed 9 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0
-- END PROG LOAD LOG --
libbpf: prog 'and': failed to load: -13
libbpf: failed to load object 'arena_atomics'
libbpf: failed to load BPF skeleton 'arena_atomics': -13
test_arena_atomics:FAIL:arena atomics skeleton load unexpected error: -13 (errno 13)
#3 arena_atomics:FAIL
The reason of the failure is due to [2] where atomic{64,}_fetch_{and,or,xor}() are not
allowed by arena addresses.
Version 2 of the patch fixed the issue by using inline asm ([3]). But further discussion
suggested to find a way from source to generate locked insn which is more user
friendly. So in not-merged llvm patch ([4]), if relax memory ordering is used and
the return value is not used, locked insn could be generated.
So with llvm patch [4] to compile the bpf selftest, the following code
__c11_atomic_fetch_and(&and64_value, 0x011ull << 32, memory_order_relaxed);
is able to generate locked insn, hence fixing the selftest failure.
[1] https://github.com/llvm/llvm-project/pull/106494
[2] d503a04f8bc0 ("bpf: Add support for certain atomics in bpf_arena to x86 JIT")
[3] https://lore.kernel.org/bpf/20240803025928.4184433-1-yonghong.song@linux.dev/
[4] https://github.com/llvm/llvm-project/pull/107343
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240909223431.1666305-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-09 15:34:31 -07:00
|
|
|
#ifdef __BPF_FEATURE_ATOMIC_MEM_ORDERING
|
|
|
|
__c11_atomic_fetch_or(&or64_value, 0x011ull << 32, memory_order_relaxed);
|
|
|
|
__c11_atomic_fetch_or(&or32_value, 0x011, memory_order_relaxed);
|
|
|
|
#else
|
2024-04-05 16:11:34 -07:00
|
|
|
__sync_fetch_and_or(&or64_value, 0x011ull << 32);
|
|
|
|
__sync_fetch_and_or(&or32_value, 0x011);
|
selftests/bpf: Fix arena_atomics failure due to llvm change
llvm change [1] made a change such that __sync_fetch_and_{and,or,xor}()
will generate atomic_fetch_*() insns even if the return value is not used.
This is a deliberate choice to make sure barrier semantics are preserved
from source code to asm insn.
But the change in [1] caused arena_atomics selftest failure.
test_arena_atomics:PASS:arena atomics skeleton open 0 nsec
libbpf: prog 'and': BPF program load failed: Permission denied
libbpf: prog 'and': -- BEGIN PROG LOAD LOG --
arg#0 reference type('UNKNOWN ') size cannot be determined: -22
0: R1=ctx() R10=fp0
; if (pid != (bpf_get_current_pid_tgid() >> 32)) @ arena_atomics.c:87
0: (18) r1 = 0xffffc90000064000 ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4)
2: (61) r6 = *(u32 *)(r1 +0) ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4) R6_w=scalar(smin=0,smax=umax=0xffffffff,v
ar_off=(0x0; 0xffffffff))
3: (85) call bpf_get_current_pid_tgid#14 ; R0_w=scalar()
4: (77) r0 >>= 32 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff))
5: (5d) if r0 != r6 goto pc+11 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) R6_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0x)
; __sync_fetch_and_and(&and64_value, 0x011ull << 32); @ arena_atomics.c:91
6: (18) r1 = 0x100000000060 ; R1_w=scalar()
8: (bf) r1 = addr_space_cast(r1, 0, 1) ; R1_w=arena
9: (18) r2 = 0x1100000000 ; R2_w=0x1100000000
11: (db) r2 = atomic64_fetch_and((u64 *)(r1 +0), r2)
BPF_ATOMIC stores into R1 arena is not allowed
processed 9 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0
-- END PROG LOAD LOG --
libbpf: prog 'and': failed to load: -13
libbpf: failed to load object 'arena_atomics'
libbpf: failed to load BPF skeleton 'arena_atomics': -13
test_arena_atomics:FAIL:arena atomics skeleton load unexpected error: -13 (errno 13)
#3 arena_atomics:FAIL
The reason of the failure is due to [2] where atomic{64,}_fetch_{and,or,xor}() are not
allowed by arena addresses.
Version 2 of the patch fixed the issue by using inline asm ([3]). But further discussion
suggested to find a way from source to generate locked insn which is more user
friendly. So in not-merged llvm patch ([4]), if relax memory ordering is used and
the return value is not used, locked insn could be generated.
So with llvm patch [4] to compile the bpf selftest, the following code
__c11_atomic_fetch_and(&and64_value, 0x011ull << 32, memory_order_relaxed);
is able to generate locked insn, hence fixing the selftest failure.
[1] https://github.com/llvm/llvm-project/pull/106494
[2] d503a04f8bc0 ("bpf: Add support for certain atomics in bpf_arena to x86 JIT")
[3] https://lore.kernel.org/bpf/20240803025928.4184433-1-yonghong.song@linux.dev/
[4] https://github.com/llvm/llvm-project/pull/107343
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240909223431.1666305-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-09 15:34:31 -07:00
|
|
|
#endif
|
2024-04-05 16:11:34 -07:00
|
|
|
#endif
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
selftests/bpf: Fix arena_atomics failure due to llvm change
llvm change [1] made a change such that __sync_fetch_and_{and,or,xor}()
will generate atomic_fetch_*() insns even if the return value is not used.
This is a deliberate choice to make sure barrier semantics are preserved
from source code to asm insn.
But the change in [1] caused arena_atomics selftest failure.
test_arena_atomics:PASS:arena atomics skeleton open 0 nsec
libbpf: prog 'and': BPF program load failed: Permission denied
libbpf: prog 'and': -- BEGIN PROG LOAD LOG --
arg#0 reference type('UNKNOWN ') size cannot be determined: -22
0: R1=ctx() R10=fp0
; if (pid != (bpf_get_current_pid_tgid() >> 32)) @ arena_atomics.c:87
0: (18) r1 = 0xffffc90000064000 ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4)
2: (61) r6 = *(u32 *)(r1 +0) ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4) R6_w=scalar(smin=0,smax=umax=0xffffffff,v
ar_off=(0x0; 0xffffffff))
3: (85) call bpf_get_current_pid_tgid#14 ; R0_w=scalar()
4: (77) r0 >>= 32 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff))
5: (5d) if r0 != r6 goto pc+11 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) R6_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0x)
; __sync_fetch_and_and(&and64_value, 0x011ull << 32); @ arena_atomics.c:91
6: (18) r1 = 0x100000000060 ; R1_w=scalar()
8: (bf) r1 = addr_space_cast(r1, 0, 1) ; R1_w=arena
9: (18) r2 = 0x1100000000 ; R2_w=0x1100000000
11: (db) r2 = atomic64_fetch_and((u64 *)(r1 +0), r2)
BPF_ATOMIC stores into R1 arena is not allowed
processed 9 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0
-- END PROG LOAD LOG --
libbpf: prog 'and': failed to load: -13
libbpf: failed to load object 'arena_atomics'
libbpf: failed to load BPF skeleton 'arena_atomics': -13
test_arena_atomics:FAIL:arena atomics skeleton load unexpected error: -13 (errno 13)
#3 arena_atomics:FAIL
The reason of the failure is due to [2] where atomic{64,}_fetch_{and,or,xor}() are not
allowed by arena addresses.
Version 2 of the patch fixed the issue by using inline asm ([3]). But further discussion
suggested to find a way from source to generate locked insn which is more user
friendly. So in not-merged llvm patch ([4]), if relax memory ordering is used and
the return value is not used, locked insn could be generated.
So with llvm patch [4] to compile the bpf selftest, the following code
__c11_atomic_fetch_and(&and64_value, 0x011ull << 32, memory_order_relaxed);
is able to generate locked insn, hence fixing the selftest failure.
[1] https://github.com/llvm/llvm-project/pull/106494
[2] d503a04f8bc0 ("bpf: Add support for certain atomics in bpf_arena to x86 JIT")
[3] https://lore.kernel.org/bpf/20240803025928.4184433-1-yonghong.song@linux.dev/
[4] https://github.com/llvm/llvm-project/pull/107343
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240909223431.1666305-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-09 15:34:31 -07:00
|
|
|
#ifdef __BPF_FEATURE_ATOMIC_MEM_ORDERING
|
|
|
|
_Atomic __u64 __arena_global xor64_value = (0x110ull << 32);
|
|
|
|
_Atomic __u32 __arena_global xor32_value = 0x110;
|
|
|
|
#else
|
2024-07-02 01:40:28 +02:00
|
|
|
__u64 __arena_global xor64_value = (0x110ull << 32);
|
|
|
|
__u32 __arena_global xor32_value = 0x110;
|
selftests/bpf: Fix arena_atomics failure due to llvm change
llvm change [1] made a change such that __sync_fetch_and_{and,or,xor}()
will generate atomic_fetch_*() insns even if the return value is not used.
This is a deliberate choice to make sure barrier semantics are preserved
from source code to asm insn.
But the change in [1] caused arena_atomics selftest failure.
test_arena_atomics:PASS:arena atomics skeleton open 0 nsec
libbpf: prog 'and': BPF program load failed: Permission denied
libbpf: prog 'and': -- BEGIN PROG LOAD LOG --
arg#0 reference type('UNKNOWN ') size cannot be determined: -22
0: R1=ctx() R10=fp0
; if (pid != (bpf_get_current_pid_tgid() >> 32)) @ arena_atomics.c:87
0: (18) r1 = 0xffffc90000064000 ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4)
2: (61) r6 = *(u32 *)(r1 +0) ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4) R6_w=scalar(smin=0,smax=umax=0xffffffff,v
ar_off=(0x0; 0xffffffff))
3: (85) call bpf_get_current_pid_tgid#14 ; R0_w=scalar()
4: (77) r0 >>= 32 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff))
5: (5d) if r0 != r6 goto pc+11 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) R6_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0x)
; __sync_fetch_and_and(&and64_value, 0x011ull << 32); @ arena_atomics.c:91
6: (18) r1 = 0x100000000060 ; R1_w=scalar()
8: (bf) r1 = addr_space_cast(r1, 0, 1) ; R1_w=arena
9: (18) r2 = 0x1100000000 ; R2_w=0x1100000000
11: (db) r2 = atomic64_fetch_and((u64 *)(r1 +0), r2)
BPF_ATOMIC stores into R1 arena is not allowed
processed 9 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0
-- END PROG LOAD LOG --
libbpf: prog 'and': failed to load: -13
libbpf: failed to load object 'arena_atomics'
libbpf: failed to load BPF skeleton 'arena_atomics': -13
test_arena_atomics:FAIL:arena atomics skeleton load unexpected error: -13 (errno 13)
#3 arena_atomics:FAIL
The reason of the failure is due to [2] where atomic{64,}_fetch_{and,or,xor}() are not
allowed by arena addresses.
Version 2 of the patch fixed the issue by using inline asm ([3]). But further discussion
suggested to find a way from source to generate locked insn which is more user
friendly. So in not-merged llvm patch ([4]), if relax memory ordering is used and
the return value is not used, locked insn could be generated.
So with llvm patch [4] to compile the bpf selftest, the following code
__c11_atomic_fetch_and(&and64_value, 0x011ull << 32, memory_order_relaxed);
is able to generate locked insn, hence fixing the selftest failure.
[1] https://github.com/llvm/llvm-project/pull/106494
[2] d503a04f8bc0 ("bpf: Add support for certain atomics in bpf_arena to x86 JIT")
[3] https://lore.kernel.org/bpf/20240803025928.4184433-1-yonghong.song@linux.dev/
[4] https://github.com/llvm/llvm-project/pull/107343
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240909223431.1666305-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-09 15:34:31 -07:00
|
|
|
#endif
|
2024-04-05 16:11:34 -07:00
|
|
|
|
|
|
|
SEC("raw_tp/sys_enter")
|
|
|
|
int xor(const void *ctx)
|
|
|
|
{
|
|
|
|
if (pid != (bpf_get_current_pid_tgid() >> 32))
|
|
|
|
return 0;
|
|
|
|
#ifdef ENABLE_ATOMICS_TESTS
|
selftests/bpf: Fix arena_atomics failure due to llvm change
llvm change [1] made a change such that __sync_fetch_and_{and,or,xor}()
will generate atomic_fetch_*() insns even if the return value is not used.
This is a deliberate choice to make sure barrier semantics are preserved
from source code to asm insn.
But the change in [1] caused arena_atomics selftest failure.
test_arena_atomics:PASS:arena atomics skeleton open 0 nsec
libbpf: prog 'and': BPF program load failed: Permission denied
libbpf: prog 'and': -- BEGIN PROG LOAD LOG --
arg#0 reference type('UNKNOWN ') size cannot be determined: -22
0: R1=ctx() R10=fp0
; if (pid != (bpf_get_current_pid_tgid() >> 32)) @ arena_atomics.c:87
0: (18) r1 = 0xffffc90000064000 ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4)
2: (61) r6 = *(u32 *)(r1 +0) ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4) R6_w=scalar(smin=0,smax=umax=0xffffffff,v
ar_off=(0x0; 0xffffffff))
3: (85) call bpf_get_current_pid_tgid#14 ; R0_w=scalar()
4: (77) r0 >>= 32 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff))
5: (5d) if r0 != r6 goto pc+11 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) R6_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0x)
; __sync_fetch_and_and(&and64_value, 0x011ull << 32); @ arena_atomics.c:91
6: (18) r1 = 0x100000000060 ; R1_w=scalar()
8: (bf) r1 = addr_space_cast(r1, 0, 1) ; R1_w=arena
9: (18) r2 = 0x1100000000 ; R2_w=0x1100000000
11: (db) r2 = atomic64_fetch_and((u64 *)(r1 +0), r2)
BPF_ATOMIC stores into R1 arena is not allowed
processed 9 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0
-- END PROG LOAD LOG --
libbpf: prog 'and': failed to load: -13
libbpf: failed to load object 'arena_atomics'
libbpf: failed to load BPF skeleton 'arena_atomics': -13
test_arena_atomics:FAIL:arena atomics skeleton load unexpected error: -13 (errno 13)
#3 arena_atomics:FAIL
The reason of the failure is due to [2] where atomic{64,}_fetch_{and,or,xor}() are not
allowed by arena addresses.
Version 2 of the patch fixed the issue by using inline asm ([3]). But further discussion
suggested to find a way from source to generate locked insn which is more user
friendly. So in not-merged llvm patch ([4]), if relax memory ordering is used and
the return value is not used, locked insn could be generated.
So with llvm patch [4] to compile the bpf selftest, the following code
__c11_atomic_fetch_and(&and64_value, 0x011ull << 32, memory_order_relaxed);
is able to generate locked insn, hence fixing the selftest failure.
[1] https://github.com/llvm/llvm-project/pull/106494
[2] d503a04f8bc0 ("bpf: Add support for certain atomics in bpf_arena to x86 JIT")
[3] https://lore.kernel.org/bpf/20240803025928.4184433-1-yonghong.song@linux.dev/
[4] https://github.com/llvm/llvm-project/pull/107343
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240909223431.1666305-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-09 15:34:31 -07:00
|
|
|
#ifdef __BPF_FEATURE_ATOMIC_MEM_ORDERING
|
|
|
|
__c11_atomic_fetch_xor(&xor64_value, 0x011ull << 32, memory_order_relaxed);
|
|
|
|
__c11_atomic_fetch_xor(&xor32_value, 0x011, memory_order_relaxed);
|
|
|
|
#else
|
2024-04-05 16:11:34 -07:00
|
|
|
__sync_fetch_and_xor(&xor64_value, 0x011ull << 32);
|
|
|
|
__sync_fetch_and_xor(&xor32_value, 0x011);
|
selftests/bpf: Fix arena_atomics failure due to llvm change
llvm change [1] made a change such that __sync_fetch_and_{and,or,xor}()
will generate atomic_fetch_*() insns even if the return value is not used.
This is a deliberate choice to make sure barrier semantics are preserved
from source code to asm insn.
But the change in [1] caused arena_atomics selftest failure.
test_arena_atomics:PASS:arena atomics skeleton open 0 nsec
libbpf: prog 'and': BPF program load failed: Permission denied
libbpf: prog 'and': -- BEGIN PROG LOAD LOG --
arg#0 reference type('UNKNOWN ') size cannot be determined: -22
0: R1=ctx() R10=fp0
; if (pid != (bpf_get_current_pid_tgid() >> 32)) @ arena_atomics.c:87
0: (18) r1 = 0xffffc90000064000 ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4)
2: (61) r6 = *(u32 *)(r1 +0) ; R1_w=map_value(map=arena_at.bss,ks=4,vs=4) R6_w=scalar(smin=0,smax=umax=0xffffffff,v
ar_off=(0x0; 0xffffffff))
3: (85) call bpf_get_current_pid_tgid#14 ; R0_w=scalar()
4: (77) r0 >>= 32 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff))
5: (5d) if r0 != r6 goto pc+11 ; R0_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) R6_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0x)
; __sync_fetch_and_and(&and64_value, 0x011ull << 32); @ arena_atomics.c:91
6: (18) r1 = 0x100000000060 ; R1_w=scalar()
8: (bf) r1 = addr_space_cast(r1, 0, 1) ; R1_w=arena
9: (18) r2 = 0x1100000000 ; R2_w=0x1100000000
11: (db) r2 = atomic64_fetch_and((u64 *)(r1 +0), r2)
BPF_ATOMIC stores into R1 arena is not allowed
processed 9 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0
-- END PROG LOAD LOG --
libbpf: prog 'and': failed to load: -13
libbpf: failed to load object 'arena_atomics'
libbpf: failed to load BPF skeleton 'arena_atomics': -13
test_arena_atomics:FAIL:arena atomics skeleton load unexpected error: -13 (errno 13)
#3 arena_atomics:FAIL
The reason of the failure is due to [2] where atomic{64,}_fetch_{and,or,xor}() are not
allowed by arena addresses.
Version 2 of the patch fixed the issue by using inline asm ([3]). But further discussion
suggested to find a way from source to generate locked insn which is more user
friendly. So in not-merged llvm patch ([4]), if relax memory ordering is used and
the return value is not used, locked insn could be generated.
So with llvm patch [4] to compile the bpf selftest, the following code
__c11_atomic_fetch_and(&and64_value, 0x011ull << 32, memory_order_relaxed);
is able to generate locked insn, hence fixing the selftest failure.
[1] https://github.com/llvm/llvm-project/pull/106494
[2] d503a04f8bc0 ("bpf: Add support for certain atomics in bpf_arena to x86 JIT")
[3] https://lore.kernel.org/bpf/20240803025928.4184433-1-yonghong.song@linux.dev/
[4] https://github.com/llvm/llvm-project/pull/107343
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240909223431.1666305-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-09 15:34:31 -07:00
|
|
|
#endif
|
2024-04-05 16:11:34 -07:00
|
|
|
#endif
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2024-07-02 01:40:28 +02:00
|
|
|
__u32 __arena_global cmpxchg32_value = 1;
|
|
|
|
__u32 __arena_global cmpxchg32_result_fail = 0;
|
|
|
|
__u32 __arena_global cmpxchg32_result_succeed = 0;
|
|
|
|
__u64 __arena_global cmpxchg64_value = 1;
|
|
|
|
__u64 __arena_global cmpxchg64_result_fail = 0;
|
|
|
|
__u64 __arena_global cmpxchg64_result_succeed = 0;
|
2024-04-05 16:11:34 -07:00
|
|
|
|
|
|
|
SEC("raw_tp/sys_enter")
|
|
|
|
int cmpxchg(const void *ctx)
|
|
|
|
{
|
|
|
|
if (pid != (bpf_get_current_pid_tgid() >> 32))
|
|
|
|
return 0;
|
|
|
|
#ifdef ENABLE_ATOMICS_TESTS
|
|
|
|
cmpxchg64_result_fail = __sync_val_compare_and_swap(&cmpxchg64_value, 0, 3);
|
|
|
|
cmpxchg64_result_succeed = __sync_val_compare_and_swap(&cmpxchg64_value, 1, 2);
|
|
|
|
|
|
|
|
cmpxchg32_result_fail = __sync_val_compare_and_swap(&cmpxchg32_value, 0, 3);
|
|
|
|
cmpxchg32_result_succeed = __sync_val_compare_and_swap(&cmpxchg32_value, 1, 2);
|
|
|
|
#endif
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2024-07-02 01:40:28 +02:00
|
|
|
__u64 __arena_global xchg64_value = 1;
|
|
|
|
__u64 __arena_global xchg64_result = 0;
|
|
|
|
__u32 __arena_global xchg32_value = 1;
|
|
|
|
__u32 __arena_global xchg32_result = 0;
|
2024-04-05 16:11:34 -07:00
|
|
|
|
|
|
|
SEC("raw_tp/sys_enter")
|
|
|
|
int xchg(const void *ctx)
|
|
|
|
{
|
|
|
|
if (pid != (bpf_get_current_pid_tgid() >> 32))
|
|
|
|
return 0;
|
|
|
|
#ifdef ENABLE_ATOMICS_TESTS
|
|
|
|
__u64 val64 = 2;
|
|
|
|
__u32 val32 = 2;
|
|
|
|
|
|
|
|
xchg64_result = __sync_lock_test_and_set(&xchg64_value, val64);
|
|
|
|
xchg32_result = __sync_lock_test_and_set(&xchg32_value, val32);
|
|
|
|
#endif
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
2024-07-02 01:40:29 +02:00
|
|
|
|
|
|
|
__u64 __arena_global uaf_sink;
|
|
|
|
volatile __u64 __arena_global uaf_recovery_fails;
|
|
|
|
|
|
|
|
SEC("syscall")
|
|
|
|
int uaf(const void *ctx)
|
|
|
|
{
|
|
|
|
if (pid != (bpf_get_current_pid_tgid() >> 32))
|
|
|
|
return 0;
|
|
|
|
#if defined(ENABLE_ATOMICS_TESTS) && !defined(__TARGET_ARCH_arm64) && \
|
|
|
|
!defined(__TARGET_ARCH_x86)
|
|
|
|
__u32 __arena *page32;
|
|
|
|
__u64 __arena *page64;
|
|
|
|
void __arena *page;
|
|
|
|
|
|
|
|
page = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0);
|
|
|
|
bpf_arena_free_pages(&arena, page, 1);
|
|
|
|
uaf_recovery_fails = 24;
|
|
|
|
|
|
|
|
page32 = (__u32 __arena *)page;
|
|
|
|
uaf_sink += __sync_fetch_and_add(page32, 1);
|
|
|
|
uaf_recovery_fails -= 1;
|
|
|
|
__sync_add_and_fetch(page32, 1);
|
|
|
|
uaf_recovery_fails -= 1;
|
|
|
|
uaf_sink += __sync_fetch_and_sub(page32, 1);
|
|
|
|
uaf_recovery_fails -= 1;
|
|
|
|
__sync_sub_and_fetch(page32, 1);
|
|
|
|
uaf_recovery_fails -= 1;
|
|
|
|
uaf_sink += __sync_fetch_and_and(page32, 1);
|
|
|
|
uaf_recovery_fails -= 1;
|
|
|
|
__sync_and_and_fetch(page32, 1);
|
|
|
|
uaf_recovery_fails -= 1;
|
|
|
|
uaf_sink += __sync_fetch_and_or(page32, 1);
|
|
|
|
uaf_recovery_fails -= 1;
|
|
|
|
__sync_or_and_fetch(page32, 1);
|
|
|
|
uaf_recovery_fails -= 1;
|
|
|
|
uaf_sink += __sync_fetch_and_xor(page32, 1);
|
|
|
|
uaf_recovery_fails -= 1;
|
|
|
|
__sync_xor_and_fetch(page32, 1);
|
|
|
|
uaf_recovery_fails -= 1;
|
|
|
|
uaf_sink += __sync_val_compare_and_swap(page32, 0, 1);
|
|
|
|
uaf_recovery_fails -= 1;
|
|
|
|
uaf_sink += __sync_lock_test_and_set(page32, 1);
|
|
|
|
uaf_recovery_fails -= 1;
|
|
|
|
|
|
|
|
page64 = (__u64 __arena *)page;
|
|
|
|
uaf_sink += __sync_fetch_and_add(page64, 1);
|
|
|
|
uaf_recovery_fails -= 1;
|
|
|
|
__sync_add_and_fetch(page64, 1);
|
|
|
|
uaf_recovery_fails -= 1;
|
|
|
|
uaf_sink += __sync_fetch_and_sub(page64, 1);
|
|
|
|
uaf_recovery_fails -= 1;
|
|
|
|
__sync_sub_and_fetch(page64, 1);
|
|
|
|
uaf_recovery_fails -= 1;
|
|
|
|
uaf_sink += __sync_fetch_and_and(page64, 1);
|
|
|
|
uaf_recovery_fails -= 1;
|
|
|
|
__sync_and_and_fetch(page64, 1);
|
|
|
|
uaf_recovery_fails -= 1;
|
|
|
|
uaf_sink += __sync_fetch_and_or(page64, 1);
|
|
|
|
uaf_recovery_fails -= 1;
|
|
|
|
__sync_or_and_fetch(page64, 1);
|
|
|
|
uaf_recovery_fails -= 1;
|
|
|
|
uaf_sink += __sync_fetch_and_xor(page64, 1);
|
|
|
|
uaf_recovery_fails -= 1;
|
|
|
|
__sync_xor_and_fetch(page64, 1);
|
|
|
|
uaf_recovery_fails -= 1;
|
|
|
|
uaf_sink += __sync_val_compare_and_swap(page64, 0, 1);
|
|
|
|
uaf_recovery_fails -= 1;
|
|
|
|
uaf_sink += __sync_lock_test_and_set(page64, 1);
|
|
|
|
uaf_recovery_fails -= 1;
|
|
|
|
#endif
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
selftests/bpf: Add selftests for load-acquire and store-release instructions
Add several ./test_progs tests:
- arena_atomics/load_acquire
- arena_atomics/store_release
- verifier_load_acquire/*
- verifier_store_release/*
- verifier_precision/bpf_load_acquire
- verifier_precision/bpf_store_release
The last two tests are added to check if backtrack_insn() handles the
new instructions correctly.
Additionally, the last test also makes sure that the verifier
"remembers" the value (in src_reg) we store-release into e.g. a stack
slot. For example, if we take a look at the test program:
#0: r1 = 8;
/* store_release((u64 *)(r10 - 8), r1); */
#1: .8byte %[store_release];
#2: r1 = *(u64 *)(r10 - 8);
#3: r2 = r10;
#4: r2 += r1;
#5: r0 = 0;
#6: exit;
At #1, if the verifier doesn't remember that we wrote 8 to the stack,
then later at #4 we would be adding an unbounded scalar value to the
stack pointer, which would cause the program to be rejected:
VERIFIER LOG:
=============
...
math between fp pointer and register with unbounded min value is not allowed
For easier CI integration, instead of using built-ins like
__atomic_{load,store}_n() which depend on the new
__BPF_FEATURE_LOAD_ACQ_STORE_REL pre-defined macro, manually craft
load-acquire/store-release instructions using __imm_insn(), as suggested
by Eduard.
All new tests depend on:
(1) Clang major version >= 18, and
(2) ENABLE_ATOMICS_TESTS is defined (currently implies -mcpu=v3 or
v4), and
(3) JIT supports load-acquire/store-release (currently arm64 and
x86-64)
In .../progs/arena_atomics.c:
/* 8-byte-aligned */
__u8 __arena_global load_acquire8_value = 0x12;
/* 1-byte hole */
__u16 __arena_global load_acquire16_value = 0x1234;
That 1-byte hole in the .addr_space.1 ELF section caused clang-17 to
crash:
fatal error: error in backend: unable to write nop sequence of 1 bytes
To work around such llvm-17 CI job failures, conditionally define
__arena_global variables as 64-bit if __clang_major__ < 18, to make sure
.addr_space.1 has no holes. Ideally we should avoid compiling this file
using clang-17 at all (arena tests depend on
__BPF_FEATURE_ADDR_SPACE_CAST, and are skipped for llvm-17 anyway), but
that is a separate topic.
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Peilin Ye <yepeilin@google.com>
Link: https://lore.kernel.org/r/1b46c6feaf0f1b6984d9ec80e500cc7383e9da1a.1741049567.git.yepeilin@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-03-04 01:06:46 +00:00
|
|
|
#if __clang_major__ >= 18
|
|
|
|
__u8 __arena_global load_acquire8_value = 0x12;
|
|
|
|
__u16 __arena_global load_acquire16_value = 0x1234;
|
|
|
|
__u32 __arena_global load_acquire32_value = 0x12345678;
|
|
|
|
__u64 __arena_global load_acquire64_value = 0x1234567890abcdef;
|
|
|
|
|
|
|
|
__u8 __arena_global load_acquire8_result = 0;
|
|
|
|
__u16 __arena_global load_acquire16_result = 0;
|
|
|
|
__u32 __arena_global load_acquire32_result = 0;
|
|
|
|
__u64 __arena_global load_acquire64_result = 0;
|
|
|
|
#else
|
|
|
|
/* clang-17 crashes if the .addr_space.1 ELF section has holes. Work around
|
|
|
|
* this issue by defining the below variables as 64-bit.
|
|
|
|
*/
|
|
|
|
__u64 __arena_global load_acquire8_value;
|
|
|
|
__u64 __arena_global load_acquire16_value;
|
|
|
|
__u64 __arena_global load_acquire32_value;
|
|
|
|
__u64 __arena_global load_acquire64_value;
|
|
|
|
|
|
|
|
__u64 __arena_global load_acquire8_result;
|
|
|
|
__u64 __arena_global load_acquire16_result;
|
|
|
|
__u64 __arena_global load_acquire32_result;
|
|
|
|
__u64 __arena_global load_acquire64_result;
|
|
|
|
#endif
|
|
|
|
|
|
|
|
SEC("raw_tp/sys_enter")
|
|
|
|
int load_acquire(const void *ctx)
|
|
|
|
{
|
|
|
|
#if defined(ENABLE_ATOMICS_TESTS) && \
|
|
|
|
defined(__BPF_FEATURE_ADDR_SPACE_CAST) && \
|
|
|
|
(defined(__TARGET_ARCH_arm64) || defined(__TARGET_ARCH_x86))
|
|
|
|
|
|
|
|
#define LOAD_ACQUIRE_ARENA(SIZEOP, SIZE, SRC, DST) \
|
|
|
|
{ asm volatile ( \
|
|
|
|
"r1 = %[" #SRC "] ll;" \
|
|
|
|
"r1 = addr_space_cast(r1, 0x0, 0x1);" \
|
|
|
|
".8byte %[load_acquire_insn];" \
|
|
|
|
"r3 = %[" #DST "] ll;" \
|
|
|
|
"r3 = addr_space_cast(r3, 0x0, 0x1);" \
|
|
|
|
"*(" #SIZE " *)(r3 + 0) = r2;" \
|
|
|
|
: \
|
|
|
|
: __imm_addr(SRC), \
|
|
|
|
__imm_insn(load_acquire_insn, \
|
|
|
|
BPF_ATOMIC_OP(BPF_##SIZEOP, BPF_LOAD_ACQ, \
|
|
|
|
BPF_REG_2, BPF_REG_1, 0)), \
|
|
|
|
__imm_addr(DST) \
|
|
|
|
: __clobber_all); } \
|
|
|
|
|
|
|
|
LOAD_ACQUIRE_ARENA(B, u8, load_acquire8_value, load_acquire8_result)
|
|
|
|
LOAD_ACQUIRE_ARENA(H, u16, load_acquire16_value,
|
|
|
|
load_acquire16_result)
|
|
|
|
LOAD_ACQUIRE_ARENA(W, u32, load_acquire32_value,
|
|
|
|
load_acquire32_result)
|
|
|
|
LOAD_ACQUIRE_ARENA(DW, u64, load_acquire64_value,
|
|
|
|
load_acquire64_result)
|
|
|
|
#undef LOAD_ACQUIRE_ARENA
|
|
|
|
|
|
|
|
#endif
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
#if __clang_major__ >= 18
|
|
|
|
__u8 __arena_global store_release8_result = 0;
|
|
|
|
__u16 __arena_global store_release16_result = 0;
|
|
|
|
__u32 __arena_global store_release32_result = 0;
|
|
|
|
__u64 __arena_global store_release64_result = 0;
|
|
|
|
#else
|
|
|
|
/* clang-17 crashes if the .addr_space.1 ELF section has holes. Work around
|
|
|
|
* this issue by defining the below variables as 64-bit.
|
|
|
|
*/
|
|
|
|
__u64 __arena_global store_release8_result;
|
|
|
|
__u64 __arena_global store_release16_result;
|
|
|
|
__u64 __arena_global store_release32_result;
|
|
|
|
__u64 __arena_global store_release64_result;
|
|
|
|
#endif
|
|
|
|
|
|
|
|
SEC("raw_tp/sys_enter")
|
|
|
|
int store_release(const void *ctx)
|
|
|
|
{
|
|
|
|
#if defined(ENABLE_ATOMICS_TESTS) && \
|
|
|
|
defined(__BPF_FEATURE_ADDR_SPACE_CAST) && \
|
|
|
|
(defined(__TARGET_ARCH_arm64) || defined(__TARGET_ARCH_x86))
|
|
|
|
|
|
|
|
#define STORE_RELEASE_ARENA(SIZEOP, DST, VAL) \
|
|
|
|
{ asm volatile ( \
|
|
|
|
"r1 = " VAL ";" \
|
|
|
|
"r2 = %[" #DST "] ll;" \
|
|
|
|
"r2 = addr_space_cast(r2, 0x0, 0x1);" \
|
|
|
|
".8byte %[store_release_insn];" \
|
|
|
|
: \
|
|
|
|
: __imm_addr(DST), \
|
|
|
|
__imm_insn(store_release_insn, \
|
|
|
|
BPF_ATOMIC_OP(BPF_##SIZEOP, BPF_STORE_REL, \
|
|
|
|
BPF_REG_2, BPF_REG_1, 0)) \
|
|
|
|
: __clobber_all); } \
|
|
|
|
|
|
|
|
STORE_RELEASE_ARENA(B, store_release8_result, "0x12")
|
|
|
|
STORE_RELEASE_ARENA(H, store_release16_result, "0x1234")
|
|
|
|
STORE_RELEASE_ARENA(W, store_release32_result, "0x12345678")
|
|
|
|
STORE_RELEASE_ARENA(DW, store_release64_result,
|
|
|
|
"0x1234567890abcdef ll")
|
|
|
|
#undef STORE_RELEASE_ARENA
|
|
|
|
|
|
|
|
#endif
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2024-07-02 01:40:29 +02:00
|
|
|
char _license[] SEC("license") = "GPL";
|