Quelle  verifier_and.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
/* Converted from tools/testing/selftests/bpf/verifier/and.c */

#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
#include "bpf_misc.h"

#define MAX_ENTRIES 11

struct test_val {
 unsigned int index;
 int foo[MAX_ENTRIES];
};

struct {
 __uint(type, BPF_MAP_TYPE_HASH);
 __uint(max_entries, 1);
 __type(key, long long);
 __type(value, struct test_val);
} map_hash_48b SEC(".maps");

SEC("socket")
__description("invalid and of negative number")
__failure __msg("R0 max value is outside of the allowed memory range")
__failure_unpriv
__flag(BPF_F_ANY_ALIGNMENT)
__naked void invalid_and_of_negative_number(void)
{
 asm volatile (" \
 r1 = 0;      \
 *(u64*)(r10 - 8) = r1;    \
 r2 = r10;     \
 r2 += -8;     \
 r1 = %[map_hash_48b] ll;   \
 call %[bpf_map_lookup_elem];   \
 if r0 == 0 goto l0_%=;    \
 r1 = *(u8*)(r0 + 0);    \
 r1 &= -4;     \
 r1 <<= 2;     \
 r0 += r1;     \
l0_%=: r1 = %[test_val_foo];    \
 *(u64*)(r0 + 0) = r1;    \
 exit;      \
" :
 : __imm(bpf_map_lookup_elem),
   __imm_addr(map_hash_48b),
   __imm_const(test_val_foo, offsetof(struct test_val, foo))
 : __clobber_all);
}

SEC("socket")
__description("invalid range check")
__failure __msg("R0 max value is outside of the allowed memory range")
__failure_unpriv
__flag(BPF_F_ANY_ALIGNMENT)
__naked void invalid_range_check(void)
{
 asm volatile (" \
 r1 = 0;      \
 *(u64*)(r10 - 8) = r1;    \
 r2 = r10;     \
 r2 += -8;     \
 r1 = %[map_hash_48b] ll;   \
 call %[bpf_map_lookup_elem];   \
 if r0 == 0 goto l0_%=;    \
 r1 = *(u32*)(r0 + 0);    \
 r9 = 1;      \
 w1 %%= 2;     \
 w1 += 1;     \
 w9 &= w1;     \
 w9 += 1;     \
 w9 >>= 1;     \
 w3 = 1;      \
 w3 -= w9;     \
 w3 *= 0x10000000;    \
 r0 += r3;     \
 *(u32*)(r0 + 0) = r3;    \
l0_%=: r0 = r0;     \
 exit;      \
" :
 : __imm(bpf_map_lookup_elem),
   __imm_addr(map_hash_48b)
 : __clobber_all);
}

SEC("socket")
__description("check known subreg with unknown reg")
__success __success_unpriv
__retval(0)
#ifdef SPEC_V1
__xlated_unpriv("if w0 < 0x1 goto pc+2")
__xlated_unpriv("nospec") /* inserted to prevent `R1 !read_ok'` */
__xlated_unpriv("goto pc-1") /* `r1 = *(u32*)(r1 + 512)`, sanitized dead code */
__xlated_unpriv("r0 = 0")
#endif
__naked void known_subreg_with_unknown_reg(void)
{
 asm volatile (" \
 call %[bpf_get_prandom_u32];   \
 r0 <<= 32;     \
 r0 += 1;     \
 r0 &= 0xFFFF1234;    \
 /* Upper bits are unknown but AND above masks out 1 zero'ing lower bits */\
 if w0 < 1 goto l0_%=;    \
 r1 = *(u32*)(r1 + 512);    \
l0_%=: r0 = 0;      \
 exit;      \
" :
 : __imm(bpf_get_prandom_u32)
 : __clobber_all);
}

char _license[] SEC("license") = "GPL";