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ci: clean up temporary patch

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It's already applied upstream.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
This commit is contained in:
Andrii Nakryiko
2024-03-25 20:29:37 -07:00
committed by Andrii Nakryiko
parent 25a9cc27d7
commit 902af6913a
1 changed files with 0 additions and 129 deletions
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129
ci/diffs/0001-selftests-bpf-test-case-for-callback_depth-states-pr.patch
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@@ -1,129 +0,0 @@
From 5c2bc5e2f81d3344095ae241032dde20a4ea2b48 Mon Sep 17 00:00:00 2001
From: Eduard Zingerman <eddyz87@gmail.com>
Date: Thu, 22 Feb 2024 17:41:21 +0200
Subject: [PATCH 1/2] selftests/bpf: test case for callback_depth states
pruning logic
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>
---
.../bpf/progs/verifier_iterating_callbacks.c | 70 +++++++++++++++++++
1 file changed, 70 insertions(+)
diff --git a/tools/testing/selftests/bpf/progs/verifier_iterating_callbacks.c b/tools/testing/selftests/bpf/progs/verifier_iterating_callbacks.c
index 5905e036e0ea..a955a6358206 100644
--- a/tools/testing/selftests/bpf/progs/verifier_iterating_callbacks.c
+++ b/tools/testing/selftests/bpf/progs/verifier_iterating_callbacks.c
@@ -239,4 +239,74 @@ int bpf_loop_iter_limit_nested(void *unused)
return 1000 * a + b + c;
}
+struct iter_limit_bug_ctx {
+ __u64 a;
+ __u64 b;
+ __u64 c;
+};
+
+static __naked void iter_limit_bug_cb(void)
+{
+ /* This is the same as C code below, but written
+ * in assembly to control which branches are fall-through.
+ *
+ * switch (bpf_get_prandom_u32()) {
+ * case 1: ctx->a = 42; break;
+ * case 2: ctx->b = 42; break;
+ * default: ctx->c = 42; break;
+ * }
+ */
+ asm volatile (
+ "r9 = r2;"
+ "call %[bpf_get_prandom_u32];"
+ "r1 = r0;"
+ "r2 = 42;"
+ "r0 = 0;"
+ "if r1 == 0x1 goto 1f;"
+ "if r1 == 0x2 goto 2f;"
+ "*(u64 *)(r9 + 16) = r2;"
+ "exit;"
+ "1: *(u64 *)(r9 + 0) = r2;"
+ "exit;"
+ "2: *(u64 *)(r9 + 8) = r2;"
+ "exit;"
+ :
+ : __imm(bpf_get_prandom_u32)
+ : __clobber_all
+ );
+}
+
+SEC("tc")
+__failure
+__flag(BPF_F_TEST_STATE_FREQ)
+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);
+
+ /* This is the same as C code below,
+ * written in assembly to guarantee checks order.
+ *
+ * if (ctx.a == 42 && ctx.b == 42 && ctx.c == 7)
+ * asm volatile("r1 /= 0;":::"r1");
+ */
+ asm volatile (
+ "r1 = *(u64 *)%[ctx_a];"
+ "if r1 != 42 goto 1f;"
+ "r1 = *(u64 *)%[ctx_b];"
+ "if r1 != 42 goto 1f;"
+ "r1 = *(u64 *)%[ctx_c];"
+ "if r1 != 7 goto 1f;"
+ "r1 /= 0;"
+ "1:"
+ :
+ : [ctx_a]"m"(ctx.a),
+ [ctx_b]"m"(ctx.b),
+ [ctx_c]"m"(ctx.c)
+ : "r1"
+ );
+ return 0;
+}
+
char _license[] SEC("license") = "GPL";
--
2.43.0