59 lines
1.4 KiB
C
59 lines
1.4 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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#include <linux/bpf.h>
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#include <bpf/bpf_helpers.h>
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#include "bpf_misc.h"
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SEC("socket")
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__description("check w reg equal if r reg upper32 bits 0")
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__success
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__naked void subreg_equality_1(void)
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{
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asm volatile (" \
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call %[bpf_ktime_get_ns]; \
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*(u64 *)(r10 - 8) = r0; \
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r2 = *(u32 *)(r10 - 8); \
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/* At this point upper 4-bytes of r2 are 0, \
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* thus insn w3 = w2 should propagate reg id, \
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* and w2 < 9 comparison would also propagate \
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* the range for r3. \
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*/ \
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w3 = w2; \
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if w2 < 9 goto l0_%=; \
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exit; \
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l0_%=: if r3 < 9 goto l1_%=; \
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/* r1 read is illegal at this point */ \
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r0 -= r1; \
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l1_%=: exit; \
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" :
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: __imm(bpf_ktime_get_ns)
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: __clobber_all);
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}
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SEC("socket")
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__description("check w reg not equal if r reg upper32 bits not 0")
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__failure __msg("R1 !read_ok")
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__naked void subreg_equality_2(void)
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{
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asm volatile (" \
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call %[bpf_ktime_get_ns]; \
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r2 = r0; \
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/* Upper 4-bytes of r2 may not be 0, thus insn \
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* w3 = w2 should not propagate reg id, and \
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* w2 < 9 comparison should not propagate \
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* the range for r3 either. \
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*/ \
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w3 = w2; \
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if w2 < 9 goto l0_%=; \
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exit; \
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l0_%=: if r3 < 9 goto l1_%=; \
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/* r1 read is illegal at this point */ \
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r0 -= r1; \
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l1_%=: exit; \
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" :
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: __imm(bpf_ktime_get_ns)
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: __clobber_all);
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}
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char _license[] SEC("license") = "GPL";
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