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