Quelle  verifier_regalloc.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
/* Converted from tools/testing/selftests/bpf/verifier/regalloc.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("tracepoint")
__description("regalloc basic")
__success __flag(BPF_F_ANY_ALIGNMENT)
__naked void regalloc_basic(void)
{
 asm volatile (" \
 r6 = r1;     \
 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_%=;    \
 r7 = r0;     \
 call %[bpf_get_prandom_u32];   \
 r2 = r0;     \
 if r0 s> 20 goto l0_%=;    \
 if r2 s< 0 goto l0_%=;    \
 r7 += r0;     \
 r7 += r2;     \
 r0 = *(u64*)(r7 + 0);    \
l0_%=: exit;      \
" :
 : __imm(bpf_get_prandom_u32),
   __imm(bpf_map_lookup_elem),
   __imm_addr(map_hash_48b)
 : __clobber_all);
}

SEC("tracepoint")
__description("regalloc negative")
__failure __msg("invalid access to map value, value_size=48 off=48 size=1")
__naked void regalloc_negative(void)
{
 asm volatile (" \
 r6 = r1;     \
 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_%=;    \
 r7 = r0;     \
 call %[bpf_get_prandom_u32];   \
 r2 = r0;     \
 if r0 s> 24 goto l0_%=;    \
 if r2 s< 0 goto l0_%=;    \
 r7 += r0;     \
 r7 += r2;     \
 r0 = *(u8*)(r7 + 0);    \
l0_%=: exit;      \
" :
 : __imm(bpf_get_prandom_u32),
   __imm(bpf_map_lookup_elem),
   __imm_addr(map_hash_48b)
 : __clobber_all);
}

SEC("tracepoint")
__description("regalloc src_reg mark")
__success __flag(BPF_F_ANY_ALIGNMENT)
__naked void regalloc_src_reg_mark(void)
{
 asm volatile (" \
 r6 = r1;     \
 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_%=;    \
 r7 = r0;     \
 call %[bpf_get_prandom_u32];   \
 r2 = r0;     \
 if r0 s> 20 goto l0_%=;    \
 r3 = 0;      \
 if r3 s>= r2 goto l0_%=;   \
 r7 += r0;     \
 r7 += r2;     \
 r0 = *(u64*)(r7 + 0);    \
l0_%=: exit;      \
" :
 : __imm(bpf_get_prandom_u32),
   __imm(bpf_map_lookup_elem),
   __imm_addr(map_hash_48b)
 : __clobber_all);
}

SEC("tracepoint")
__description("regalloc src_reg negative")
__failure __msg("invalid access to map value, value_size=48 off=44 size=8")
__flag(BPF_F_ANY_ALIGNMENT)
__naked void regalloc_src_reg_negative(void)
{
 asm volatile (" \
 r6 = r1;     \
 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_%=;    \
 r7 = r0;     \
 call %[bpf_get_prandom_u32];   \
 r2 = r0;     \
 if r0 s> 22 goto l0_%=;    \
 r3 = 0;      \
 if r3 s>= r2 goto l0_%=;   \
 r7 += r0;     \
 r7 += r2;     \
 r0 = *(u64*)(r7 + 0);    \
l0_%=: exit;      \
" :
 : __imm(bpf_get_prandom_u32),
   __imm(bpf_map_lookup_elem),
   __imm_addr(map_hash_48b)
 : __clobber_all);
}

SEC("tracepoint")
__description("regalloc and spill")
__success __flag(BPF_F_ANY_ALIGNMENT)
__naked void regalloc_and_spill(void)
{
 asm volatile (" \
 r6 = r1;     \
 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_%=;    \
 r7 = r0;     \
 call %[bpf_get_prandom_u32];   \
 r2 = r0;     \
 if r0 s> 20 goto l0_%=;    \
 /* r0 has upper bound that should propagate into r2 */\
 *(u64*)(r10 - 8) = r2;  /* spill r2 */ \
 r0 = 0;      \
 r2 = 0;    /* clear r0 and r2 */\
 r3 = *(u64*)(r10 - 8);  /* fill r3 */ \
 if r0 s>= r3 goto l0_%=;   \
 /* r3 has lower and upper bounds */ \
 r7 += r3;     \
 r0 = *(u64*)(r7 + 0);    \
l0_%=: exit;      \
" :
 : __imm(bpf_get_prandom_u32),
   __imm(bpf_map_lookup_elem),
   __imm_addr(map_hash_48b)
 : __clobber_all);
}

SEC("tracepoint")
__description("regalloc and spill negative")
__failure __msg("invalid access to map value, value_size=48 off=48 size=8")
__flag(BPF_F_ANY_ALIGNMENT)
__naked void regalloc_and_spill_negative(void)
{
 asm volatile (" \
 r6 = r1;     \
 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_%=;    \
 r7 = r0;     \
 call %[bpf_get_prandom_u32];   \
 r2 = r0;     \
 if r0 s> 48 goto l0_%=;    \
 /* r0 has upper bound that should propagate into r2 */\
 *(u64*)(r10 - 8) = r2;  /* spill r2 */ \
 r0 = 0;      \
 r2 = 0;    /* clear r0 and r2 */\
 r3 = *(u64*)(r10 - 8);  /* fill r3 */\
 if r0 s>= r3 goto l0_%=;   \
 /* r3 has lower and upper bounds */ \
 r7 += r3;     \
 r0 = *(u64*)(r7 + 0);    \
l0_%=: exit;      \
" :
 : __imm(bpf_get_prandom_u32),
   __imm(bpf_map_lookup_elem),
   __imm_addr(map_hash_48b)
 : __clobber_all);
}

SEC("tracepoint")
__description("regalloc three regs")
__success __flag(BPF_F_ANY_ALIGNMENT)
__naked void regalloc_three_regs(void)
{
 asm volatile (" \
 r6 = r1;     \
 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_%=;    \
 r7 = r0;     \
 call %[bpf_get_prandom_u32];   \
 r2 = r0;     \
 r4 = r2;     \
 if r0 s> 12 goto l0_%=;    \
 if r2 s< 0 goto l0_%=;    \
 r7 += r0;     \
 r7 += r2;     \
 r7 += r4;     \
 r0 = *(u64*)(r7 + 0);    \
l0_%=: exit;      \
" :
 : __imm(bpf_get_prandom_u32),
   __imm(bpf_map_lookup_elem),
   __imm_addr(map_hash_48b)
 : __clobber_all);
}

SEC("tracepoint")
__description("regalloc after call")
__success __flag(BPF_F_ANY_ALIGNMENT)
__naked void regalloc_after_call(void)
{
 asm volatile (" \
 r6 = r1;     \
 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_%=;    \
 r7 = r0;     \
 call %[bpf_get_prandom_u32];   \
 r8 = r0;     \
 r9 = r0;     \
 call regalloc_after_call__1;   \
 if r8 s> 20 goto l0_%=;    \
 if r9 s< 0 goto l0_%=;    \
 r7 += r8;     \
 r7 += r9;     \
 r0 = *(u64*)(r7 + 0);    \
l0_%=: exit;      \
" :
 : __imm(bpf_get_prandom_u32),
   __imm(bpf_map_lookup_elem),
   __imm_addr(map_hash_48b)
 : __clobber_all);
}

static __naked __noinline __attribute__((used))
void regalloc_after_call__1(void)
{
 asm volatile (" \
 r0 = 0;      \
 exit;      \
" ::: __clobber_all);
}

SEC("tracepoint")
__description("regalloc in callee")
__success __flag(BPF_F_ANY_ALIGNMENT)
__naked void regalloc_in_callee(void)
{
 asm volatile (" \
 r6 = r1;     \
 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_%=;    \
 r7 = r0;     \
 call %[bpf_get_prandom_u32];   \
 r1 = r0;     \
 r2 = r0;     \
 r3 = r7;     \
 call regalloc_in_callee__1;   \
l0_%=: exit;      \
" :
 : __imm(bpf_get_prandom_u32),
   __imm(bpf_map_lookup_elem),
   __imm_addr(map_hash_48b)
 : __clobber_all);
}

static __naked __noinline __attribute__((used))
void regalloc_in_callee__1(void)
{
 asm volatile (" \
 if r1 s> 20 goto l0_%=;    \
 if r2 s< 0 goto l0_%=;    \
 r3 += r1;     \
 r3 += r2;     \
 r0 = *(u64*)(r3 + 0);    \
 exit;      \
l0_%=: r0 = 0;      \
 exit;      \
" ::: __clobber_all);
}

SEC("tracepoint")
__description("regalloc, spill, JEQ")
__success
__naked void regalloc_spill_jeq(void)
{
 asm volatile (" \
 r6 = r1;     \
 r1 = 0;      \
 *(u64*)(r10 - 8) = r1;    \
 r2 = r10;     \
 r2 += -8;     \
 r1 = %[map_hash_48b] ll;   \
 call %[bpf_map_lookup_elem];   \
 *(u64*)(r10 - 8) = r0;  /* spill r0 */ \
 if r0 == 0 goto l0_%=;    \
l0_%=: /* The verifier will walk the rest twice with r0 == 0 and r0 == map_value */\
 call %[bpf_get_prandom_u32];   \
 r2 = r0;     \
 if r2 == 20 goto l1_%=;    \
l1_%=: /* The verifier will walk the rest two more times with r0 == 20 and r0 == unknown */\
 r3 = *(u64*)(r10 - 8);  /* fill r3 with map_value */\
 if r3 == 0 goto l2_%=;  /* skip ldx if map_value == NULL */\
 /* Buggy verifier will think that r3 == 20 here */\
 r0 = *(u64*)(r3 + 0);  /* read from map_value */\
l2_%=: exit;      \
" :
 : __imm(bpf_get_prandom_u32),
   __imm(bpf_map_lookup_elem),
   __imm_addr(map_hash_48b)
 : __clobber_all);
}

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