numam-dpdk/lib/bpf/bpf_load.c
Henning Schild 0832959682 bpf: avoid useless memcpy call
There is no point in such a call and UBSan complains about a call to
memcpy with a null pointer as second arg.

When building with -Db_sanitize=undefined, Clang gives the following
warning
../lib/bpf/bpf_load.c:37:20: runtime error: null pointer passed as
	argument 2, which is declared to never be null

A check of the sz before calling memcpy fixes that.

Signed-off-by: Henning Schild <henning.schild@siemens.com>
2022-09-21 15:04:45 +02:00

126 lines
2.3 KiB
C

/* SPDX-License-Identifier: BSD-3-Clause
* Copyright(c) 2018 Intel Corporation
*/
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <stdint.h>
#include <rte_log.h>
#include <rte_errno.h>
#include "bpf_impl.h"
static struct rte_bpf *
bpf_load(const struct rte_bpf_prm *prm)
{
uint8_t *buf;
struct rte_bpf *bpf;
size_t sz, bsz, insz, xsz;
xsz = prm->nb_xsym * sizeof(prm->xsym[0]);
insz = prm->nb_ins * sizeof(prm->ins[0]);
bsz = sizeof(bpf[0]);
sz = insz + xsz + bsz;
buf = mmap(NULL, sz, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (buf == MAP_FAILED)
return NULL;
bpf = (void *)buf;
bpf->sz = sz;
memcpy(&bpf->prm, prm, sizeof(bpf->prm));
if (xsz > 0)
memcpy(buf + bsz, prm->xsym, xsz);
memcpy(buf + bsz + xsz, prm->ins, insz);
bpf->prm.xsym = (void *)(buf + bsz);
bpf->prm.ins = (void *)(buf + bsz + xsz);
return bpf;
}
/*
* Check that user provided external symbol.
*/
static int
bpf_check_xsym(const struct rte_bpf_xsym *xsym)
{
uint32_t i;
if (xsym->name == NULL)
return -EINVAL;
if (xsym->type == RTE_BPF_XTYPE_VAR) {
if (xsym->var.desc.type == RTE_BPF_ARG_UNDEF)
return -EINVAL;
} else if (xsym->type == RTE_BPF_XTYPE_FUNC) {
if (xsym->func.nb_args > EBPF_FUNC_MAX_ARGS)
return -EINVAL;
/* check function arguments */
for (i = 0; i != xsym->func.nb_args; i++) {
if (xsym->func.args[i].type == RTE_BPF_ARG_UNDEF)
return -EINVAL;
}
/* check return value info */
if (xsym->func.ret.type != RTE_BPF_ARG_UNDEF &&
xsym->func.ret.size == 0)
return -EINVAL;
} else
return -EINVAL;
return 0;
}
struct rte_bpf *
rte_bpf_load(const struct rte_bpf_prm *prm)
{
struct rte_bpf *bpf;
int32_t rc;
uint32_t i;
if (prm == NULL || prm->ins == NULL ||
(prm->nb_xsym != 0 && prm->xsym == NULL)) {
rte_errno = EINVAL;
return NULL;
}
rc = 0;
for (i = 0; i != prm->nb_xsym && rc == 0; i++)
rc = bpf_check_xsym(prm->xsym + i);
if (rc != 0) {
rte_errno = -rc;
RTE_BPF_LOG(ERR, "%s: %d-th xsym is invalid\n", __func__, i);
return NULL;
}
bpf = bpf_load(prm);
if (bpf == NULL) {
rte_errno = ENOMEM;
return NULL;
}
rc = bpf_validate(bpf);
if (rc == 0) {
bpf_jit(bpf);
if (mprotect(bpf, bpf->sz, PROT_READ) != 0)
rc = -ENOMEM;
}
if (rc != 0) {
rte_bpf_destroy(bpf);
rte_errno = -rc;
return NULL;
}
return bpf;
}