Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
Merge branch 'bpf-live-registers-computation-with-gotox'
Anton Protopopov says:
====================
bpf: Live registers computation with gotox
While adding a selftest for live registers computation with gotox,
I've noticed that the code is actually incomplete. Namely, the
destination register rX in `gotox rX` wasn't actually considered
as used. Fix this and add a selftest.
v1 -> v2:
* only enable the new selftest on x86 and arm64
v1: https://lore.kernel.org/bpf/20260114113314.32649-1-a.s.protopopov@gmail.com/T/#t
====================
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://patch.msgid.link/20260114162544.83253-1-a.s.protopopov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
+47
+6
kernel/bpf/verifier.c
+6
kernel/bpf/verifier.c
+41
tools/testing/selftests/bpf/progs/compute_live_registers.c
+41
tools/testing/selftests/bpf/progs/compute_live_registers.c
···
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::: __clobber_all);
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}
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+
#if defined(__TARGET_ARCH_x86) || defined(__TARGET_ARCH_arm64)
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+
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SEC("socket")
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__log_level(2)
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__msg("2: .1........ (07) r1 += 8")
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__msg("3: .1........ (79) r2 = *(u64 *)(r1 +0)")
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__msg("4: ..2....... (b7) r3 = 1")
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__msg("5: ..23...... (b7) r4 = 2")
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__msg("6: ..234..... (0d) gotox r2")
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__msg("7: ...3...... (bf) r0 = r3")
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__msg("8: 0......... (95) exit")
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__msg("9: ....4..... (bf) r0 = r4")
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__msg("10: 0......... (95) exit")
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__naked
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void gotox(void)
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{
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asm volatile (
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".pushsection .jumptables,\"\",@progbits;"
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"jt0_%=: .quad l0_%= - socket;"
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".quad l1_%= - socket;"
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".size jt0_%=, 16;"
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".global jt0_%=;"
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".popsection;"
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+
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"r1 = jt0_%= ll;"
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"r1 += 8;"
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"r2 = *(u64 *)(r1 + 0);"
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"r3 = 1;"
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"r4 = 2;"
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".8byte %[gotox_r2];"
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"l0_%=: r0 = r3;"
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"exit;"
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"l1_%=: r0 = r4;"
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"exit;"
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:
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: __imm_insn(gotox_r2, BPF_RAW_INSN(BPF_JMP | BPF_JA | BPF_X, BPF_REG_2, BPF_REG_0, 0, 0))
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: __clobber_all);
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}
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+
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#endif /* __TARGET_ARCH_x86 || __TARGET_ARCH_arm64 */
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+
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/* to retain debug info for BTF generation */
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void kfunc_root(void)
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{