From: Maxim Mikityanskiy <maxtram95@gmail.com>
To: Eduard Zingerman <eddyz87@gmail.com>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>,
Martin KaFai Lau <martin.lau@linux.dev>,
Song Liu <song@kernel.org>,
Yonghong Song <yonghong.song@linux.dev>,
KP Singh <kpsingh@kernel.org>,
Stanislav Fomichev <sdf@google.com>, Hao Luo <haoluo@google.com>,
Jiri Olsa <jolsa@kernel.org>, Mykola Lysenko <mykolal@fb.com>,
Shuah Khan <shuah@kernel.org>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Jesper Dangaard Brouer <hawk@kernel.org>,
bpf@vger.kernel.org, linux-kselftest@vger.kernel.org,
netdev@vger.kernel.org, Maxim Mikityanskiy <maxim@isovalent.com>
Subject: [PATCH bpf-next 07/15] bpf: Add the get_reg_width function
Date: Wed, 20 Dec 2023 23:40:05 +0200 [thread overview]
Message-ID: <20231220214013.3327288-8-maxtram95@gmail.com> (raw)
In-Reply-To: <20231220214013.3327288-1-maxtram95@gmail.com>
From: Maxim Mikityanskiy <maxim@isovalent.com>
Put calculation of the register value width into a dedicated function.
This function will also be used in a following commit.
Signed-off-by: Maxim Mikityanskiy <maxim@isovalent.com>
---
kernel/bpf/verifier.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index a703e3adedd3..b757fdbbbdd2 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -4448,6 +4448,11 @@ static bool is_bpf_st_mem(struct bpf_insn *insn)
return BPF_CLASS(insn->code) == BPF_ST && BPF_MODE(insn->code) == BPF_MEM;
}
+static int get_reg_width(struct bpf_reg_state *reg)
+{
+ return fls64(reg->umax_value);
+}
+
/* check_stack_{read,write}_fixed_off functions track spill/fill of registers,
* stack boundary and alignment are checked in check_mem_access()
*/
@@ -4500,7 +4505,7 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
if (reg && !(off % BPF_REG_SIZE) && register_is_bounded(reg) && env->bpf_capable) {
save_register_state(env, state, spi, reg, size);
/* Break the relation on a narrowing spill. */
- if (fls64(reg->umax_value) > BITS_PER_BYTE * size)
+ if (get_reg_width(reg) > BITS_PER_BYTE * size)
state->stack[spi].spilled_ptr.id = 0;
} else if (!reg && !(off % BPF_REG_SIZE) && is_bpf_st_mem(insn) &&
insn->imm != 0 && env->bpf_capable) {
@@ -13940,7 +13945,7 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn)
return -EACCES;
} else if (src_reg->type == SCALAR_VALUE) {
if (insn->off == 0) {
- bool is_src_reg_u32 = src_reg->umax_value <= U32_MAX;
+ bool is_src_reg_u32 = get_reg_width(src_reg) <= 32;
if (is_src_reg_u32)
assign_scalar_id_before_mov(env, src_reg);
--
2.42.1
next prev parent reply other threads:[~2023-12-20 21:40 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-20 21:39 [PATCH bpf-next 00/15] Improvements for tracking scalars in the BPF verifier Maxim Mikityanskiy
2023-12-20 21:39 ` [PATCH bpf-next 01/15] selftests/bpf: Fix the u64_offset_to_skb_data test Maxim Mikityanskiy
2023-12-26 9:52 ` Shung-Hsi Yu
2023-12-26 10:38 ` Maxim Mikityanskiy
2023-12-26 13:22 ` Shung-Hsi Yu
2024-01-04 2:22 ` Eduard Zingerman
2023-12-20 21:40 ` [PATCH bpf-next 02/15] bpf: make infinite loop detection in is_state_visited() exact Maxim Mikityanskiy
2023-12-20 21:40 ` [PATCH bpf-next 03/15] selftests/bpf: check if imprecise stack spills confuse infinite loop detection Maxim Mikityanskiy
2023-12-20 21:40 ` [PATCH bpf-next 04/15] bpf: Make bpf_for_each_spilled_reg consider narrow spills Maxim Mikityanskiy
2024-01-04 2:25 ` Eduard Zingerman
2023-12-20 21:40 ` [PATCH bpf-next 05/15] selftests/bpf: Add a test case for 32-bit spill tracking Maxim Mikityanskiy
2024-01-04 2:25 ` Eduard Zingerman
2023-12-20 21:40 ` [PATCH bpf-next 06/15] bpf: Add the assign_scalar_id_before_mov function Maxim Mikityanskiy
2024-01-04 2:26 ` Eduard Zingerman
2023-12-20 21:40 ` Maxim Mikityanskiy [this message]
2023-12-20 21:40 ` [PATCH bpf-next 08/15] bpf: Assign ID to scalars on spill Maxim Mikityanskiy
2023-12-25 3:15 ` Alexei Starovoitov
2023-12-25 21:11 ` Maxim Mikityanskiy
2023-12-25 21:26 ` Alexei Starovoitov
2024-01-04 2:26 ` Eduard Zingerman
2023-12-20 21:40 ` [PATCH bpf-next 09/15] selftests/bpf: Test assigning " Maxim Mikityanskiy
2024-01-04 2:26 ` Eduard Zingerman
2023-12-20 21:40 ` [PATCH bpf-next 10/15] bpf: Track spilled unbounded scalars Maxim Mikityanskiy
2024-01-04 2:26 ` Eduard Zingerman
2023-12-20 21:40 ` [PATCH bpf-next 11/15] selftests/bpf: Test tracking " Maxim Mikityanskiy
2024-01-04 2:26 ` Eduard Zingerman
2023-12-20 21:40 ` [PATCH bpf-next 12/15] bpf: Preserve boundaries and track scalars on narrowing fill Maxim Mikityanskiy
2023-12-26 5:29 ` Shung-Hsi Yu
2024-01-04 2:27 ` Eduard Zingerman
2024-01-05 17:48 ` Maxim Mikityanskiy
2023-12-20 21:40 ` [PATCH bpf-next 13/15] selftests/bpf: Add test cases for " Maxim Mikityanskiy
2024-01-04 2:26 ` Eduard Zingerman
2023-12-20 21:40 ` [PATCH bpf-next 14/15] bpf: Optimize state pruning for spilled scalars Maxim Mikityanskiy
2023-12-20 21:40 ` [PATCH bpf-next 15/15] selftests/bpf: states pruning checks for scalar vs STACK_{MISC,ZERO} Maxim Mikityanskiy
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