From: Shung-Hsi Yu <shung-hsi.yu@suse.com> mainline inclusion from mainline-v6.7-rc1 commit 3c41971550f58f2e006c58aa71e8c23ad312110f category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/ICL1HS Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- As seen from previous commit that fix backtracking for BPF_ALU | BPF_TO_BE | BPF_END, both BPF_NEG and BPF_END require special handling. Add tests written with inline assembly to check that the verifier does not incorrecly use the src_reg field of BPF_NEG and BPF_END (including bswap added in v4). Suggested-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Link: https://lore.kernel.org/r/20231102053913.12004-4-shung-hsi.yu@suse.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Pu Lehui <pulehui@huawei.com> --- .../selftests/bpf/prog_tests/verifier.c | 2 + .../selftests/bpf/progs/verifier_precision.c | 93 +++++++++++++++++++ 2 files changed, 95 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/verifier_precision.c diff --git a/tools/testing/selftests/bpf/prog_tests/verifier.c b/tools/testing/selftests/bpf/prog_tests/verifier.c index e51d11c36a21..5cfa7a6316b6 100644 --- a/tools/testing/selftests/bpf/prog_tests/verifier.c +++ b/tools/testing/selftests/bpf/prog_tests/verifier.c @@ -47,6 +47,7 @@ #include "verifier_movsx.skel.h" #include "verifier_netfilter_ctx.skel.h" #include "verifier_netfilter_retcode.skel.h" +#include "verifier_precision.skel.h" #include "verifier_prevent_map_lookup.skel.h" #include "verifier_raw_stack.skel.h" #include "verifier_raw_tp_writable.skel.h" @@ -155,6 +156,7 @@ void test_verifier_meta_access(void) { RUN(verifier_meta_access); } void test_verifier_movsx(void) { RUN(verifier_movsx); } void test_verifier_netfilter_ctx(void) { RUN(verifier_netfilter_ctx); } void test_verifier_netfilter_retcode(void) { RUN(verifier_netfilter_retcode); } +void test_verifier_precision(void) { RUN(verifier_precision); } void test_verifier_prevent_map_lookup(void) { RUN(verifier_prevent_map_lookup); } void test_verifier_raw_stack(void) { RUN(verifier_raw_stack); } void test_verifier_raw_tp_writable(void) { RUN(verifier_raw_tp_writable); } diff --git a/tools/testing/selftests/bpf/progs/verifier_precision.c b/tools/testing/selftests/bpf/progs/verifier_precision.c new file mode 100644 index 000000000000..193c0f8272d0 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/verifier_precision.c @@ -0,0 +1,93 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) 2023 SUSE LLC */ +#include <linux/bpf.h> +#include <bpf/bpf_helpers.h> +#include "bpf_misc.h" + +SEC("?raw_tp") +__success __log_level(2) +__msg("mark_precise: frame0: regs=r2 stack= before 3: (bf) r1 = r10") +__msg("mark_precise: frame0: regs=r2 stack= before 2: (55) if r2 != 0xfffffff8 goto pc+2") +__msg("mark_precise: frame0: regs=r2 stack= before 1: (87) r2 = -r2") +__msg("mark_precise: frame0: regs=r2 stack= before 0: (b7) r2 = 8") +__naked int bpf_neg(void) +{ + asm volatile ( + "r2 = 8;" + "r2 = -r2;" + "if r2 != -8 goto 1f;" + "r1 = r10;" + "r1 += r2;" + "1:" + "r0 = 0;" + "exit;" + ::: __clobber_all); +} + +SEC("?raw_tp") +__success __log_level(2) +__msg("mark_precise: frame0: regs=r2 stack= before 3: (bf) r1 = r10") +__msg("mark_precise: frame0: regs=r2 stack= before 2: (55) if r2 != 0x0 goto pc+2") +__msg("mark_precise: frame0: regs=r2 stack= before 1: (d4) r2 = le16 r2") +__msg("mark_precise: frame0: regs=r2 stack= before 0: (b7) r2 = 0") +__naked int bpf_end_to_le(void) +{ + asm volatile ( + "r2 = 0;" + "r2 = le16 r2;" + "if r2 != 0 goto 1f;" + "r1 = r10;" + "r1 += r2;" + "1:" + "r0 = 0;" + "exit;" + ::: __clobber_all); +} + + +SEC("?raw_tp") +__success __log_level(2) +__msg("mark_precise: frame0: regs=r2 stack= before 3: (bf) r1 = r10") +__msg("mark_precise: frame0: regs=r2 stack= before 2: (55) if r2 != 0x0 goto pc+2") +__msg("mark_precise: frame0: regs=r2 stack= before 1: (dc) r2 = be16 r2") +__msg("mark_precise: frame0: regs=r2 stack= before 0: (b7) r2 = 0") +__naked int bpf_end_to_be(void) +{ + asm volatile ( + "r2 = 0;" + "r2 = be16 r2;" + "if r2 != 0 goto 1f;" + "r1 = r10;" + "r1 += r2;" + "1:" + "r0 = 0;" + "exit;" + ::: __clobber_all); +} + +#if (defined(__TARGET_ARCH_arm64) || defined(__TARGET_ARCH_x86) || \ + (defined(__TARGET_ARCH_riscv) && __riscv_xlen == 64) || \ + defined(__TARGET_ARCH_arm) || defined(__TARGET_ARCH_s390)) && \ + __clang_major__ >= 18 + +SEC("?raw_tp") +__success __log_level(2) +__msg("mark_precise: frame0: regs=r2 stack= before 3: (bf) r1 = r10") +__msg("mark_precise: frame0: regs=r2 stack= before 2: (55) if r2 != 0x0 goto pc+2") +__msg("mark_precise: frame0: regs=r2 stack= before 1: (d7) r2 = bswap16 r2") +__msg("mark_precise: frame0: regs=r2 stack= before 0: (b7) r2 = 0") +__naked int bpf_end_bswap(void) +{ + asm volatile ( + "r2 = 0;" + "r2 = bswap16 r2;" + "if r2 != 0 goto 1f;" + "r1 = r10;" + "r1 += r2;" + "1:" + "r0 = 0;" + "exit;" + ::: __clobber_all); +} + +#endif /* v4 instruction */ -- 2.34.1