Commit cda18e97 authored by Daniel Borkmann's avatar Daniel Borkmann
Browse files

Merge branch 'bpf-dump-and-disasm-nfp-jit' 



Jakub Kicinski says:

====================
Jiong says:

Currently bpftool could disassemble host jited image, for example x86_64,
using libbfd. However it couldn't disassemble offload jited image.

There are two reasons:

  1. bpf_obj_get_info_by_fd/struct bpf_prog_info couldn't get the address
     of jited image and image's length.

  2. Even after issue 1 resolved, bpftool couldn't figure out what is the
     offload arch from bpf_prog_info, therefore can't drive libbfd
     disassembler correctly.

  This patch set resolve issue 1 by introducing two new fields "jited_len"
and "jited_image" in bpf_dev_offload. These two fields serve as the generic
interface to communicate the jited image address and length for all offload
targets to higher level caller. For example, bpf_obj_get_info_by_fd could
use them to fill the userspace visible fields jited_prog_len and
jited_prog_insns.

  This patch set resolve issue 2 by getting bfd backend name through
"ifindex", i.e network interface index.

v1:
 - Deduct bfd arch name through ifindex, i.e network interface index.
   First, map ifindex to devname through ifindex_to_name_ns, then get
   pci id through /sys/class/dev/DEVNAME/device/vendor. (Daniel, Alexei)
====================

Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parents 4f7d5851 e6593596

drivers/net/ethernet/netronome/nfp/bpf/offload.c

+9 −1
Original line number Diff line number Diff line
@@ -127,6 +127,7 @@ static int nfp_bpf_translate(struct nfp_net *nn, struct bpf_prog *prog) 
	struct nfp_prog *nfp_prog = prog->aux->offload->dev_priv;

	unsigned int stack_size;

	unsigned int max_instr;

	int err;



	stack_size = nn_readb(nn, NFP_NET_CFG_BPF_STACK_SZ) * 64;

	if (prog->aux->stack_depth > stack_size) {
@@ -143,7 +144,14 @@ static int nfp_bpf_translate(struct nfp_net *nn, struct bpf_prog *prog) 
	if (!nfp_prog->prog)

		return -ENOMEM;



	return nfp_bpf_jit(nfp_prog);

	err = nfp_bpf_jit(nfp_prog);

	if (err)

		return err;



	prog->aux->offload->jited_len = nfp_prog->prog_len * sizeof(u64);

	prog->aux->offload->jited_image = nfp_prog->prog;



	return 0;

}



static int nfp_bpf_destroy(struct nfp_net *nn, struct bpf_prog *prog)

include/linux/bpf.h

+2 −0
Original line number Diff line number Diff line
@@ -234,6 +234,8 @@ struct bpf_prog_offload { 
	struct list_head	offloads;

	bool			dev_state;

	const struct bpf_prog_offload_ops *dev_ops;

	void			*jited_image;

	u32			jited_len;

};



struct bpf_prog_aux {

kernel/bpf/offload.c

+23 −0
Original line number Diff line number Diff line
@@ -230,9 +230,12 @@ int bpf_prog_offload_info_fill(struct bpf_prog_info *info, 
		.prog	= prog,

		.info	= info,

	};

	struct bpf_prog_aux *aux = prog->aux;

	struct inode *ns_inode;

	struct path ns_path;

	char __user *uinsns;

	void *res;

	u32 ulen;



	res = ns_get_path_cb(&ns_path, bpf_prog_offload_info_fill_ns, &args);

	if (IS_ERR(res)) {
@@ -241,6 +244,26 @@ int bpf_prog_offload_info_fill(struct bpf_prog_info *info, 
		return PTR_ERR(res);

	}



	down_read(&bpf_devs_lock);



	if (!aux->offload) {

		up_read(&bpf_devs_lock);

		return -ENODEV;

	}



	ulen = info->jited_prog_len;

	info->jited_prog_len = aux->offload->jited_len;

	if (info->jited_prog_len & ulen) {

		uinsns = u64_to_user_ptr(info->jited_prog_insns);

		ulen = min_t(u32, info->jited_prog_len, ulen);

		if (copy_to_user(uinsns, aux->offload->jited_image, ulen)) {

			up_read(&bpf_devs_lock);

			return -EFAULT;

		}

	}



	up_read(&bpf_devs_lock);



	ns_inode = ns_path.dentry->d_inode;

	info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev);

	info->netns_ino = ns_inode->i_ino;

kernel/bpf/syscall.c

+18 −13
Original line number Diff line number Diff line
@@ -1724,19 +1724,6 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, 
		goto done;

	}



	ulen = info.jited_prog_len;

	info.jited_prog_len = prog->jited_len;

	if (info.jited_prog_len && ulen) {

		if (bpf_dump_raw_ok()) {

			uinsns = u64_to_user_ptr(info.jited_prog_insns);

			ulen = min_t(u32, info.jited_prog_len, ulen);

			if (copy_to_user(uinsns, prog->bpf_func, ulen))

				return -EFAULT;

		} else {

			info.jited_prog_insns = 0;

		}

	}



	ulen = info.xlated_prog_len;

	info.xlated_prog_len = bpf_prog_insn_size(prog);

	if (info.xlated_prog_len && ulen) {
@@ -1762,6 +1749,24 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, 
		err = bpf_prog_offload_info_fill(&info, prog);

		if (err)

			return err;

		goto done;

	}



	/* NOTE: the following code is supposed to be skipped for offload.

	 * bpf_prog_offload_info_fill() is the place to fill similar fields

	 * for offload.

	 */

	ulen = info.jited_prog_len;

	info.jited_prog_len = prog->jited_len;

	if (info.jited_prog_len && ulen) {

		if (bpf_dump_raw_ok()) {

			uinsns = u64_to_user_ptr(info.jited_prog_insns);

			ulen = min_t(u32, info.jited_prog_len, ulen);

			if (copy_to_user(uinsns, prog->bpf_func, ulen))

				return -EFAULT;

		} else {

			info.jited_prog_insns = 0;

		}

	}



done:

tools/bpf/bpftool/common.c

+72 −0
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ 
/* Author: Jakub Kicinski <kubakici@wp.pl> */



#include <errno.h>

#include <fcntl.h>

#include <fts.h>

#include <libgen.h>

#include <mntent.h>
@@ -433,6 +434,77 @@ ifindex_to_name_ns(__u32 ifindex, __u32 ns_dev, __u32 ns_ino, char *buf) 
	return if_indextoname(ifindex, buf);

}



static int read_sysfs_hex_int(char *path)

{

	char vendor_id_buf[8];

	int len;

	int fd;



	fd = open(path, O_RDONLY);

	if (fd < 0) {

		p_err("Can't open %s: %s", path, strerror(errno));

		return -1;

	}



	len = read(fd, vendor_id_buf, sizeof(vendor_id_buf));

	close(fd);

	if (len < 0) {

		p_err("Can't read %s: %s", path, strerror(errno));

		return -1;

	}

	if (len >= (int)sizeof(vendor_id_buf)) {

		p_err("Value in %s too long", path);

		return -1;

	}



	vendor_id_buf[len] = 0;



	return strtol(vendor_id_buf, NULL, 0);

}



static int read_sysfs_netdev_hex_int(char *devname, const char *entry_name)

{

	char full_path[64];



	snprintf(full_path, sizeof(full_path), "/sys/class/net/%s/device/%s",

		 devname, entry_name);



	return read_sysfs_hex_int(full_path);

}



const char *ifindex_to_bfd_name_ns(__u32 ifindex, __u64 ns_dev, __u64 ns_ino)

{

	char devname[IF_NAMESIZE];

	int vendor_id;

	int device_id;



	if (!ifindex_to_name_ns(ifindex, ns_dev, ns_ino, devname)) {

		p_err("Can't get net device name for ifindex %d: %s", ifindex,

		      strerror(errno));

		return NULL;

	}



	vendor_id = read_sysfs_netdev_hex_int(devname, "vendor");

	if (vendor_id < 0) {

		p_err("Can't get device vendor id for %s", devname);

		return NULL;

	}



	switch (vendor_id) {

	case 0x19ee:

		device_id = read_sysfs_netdev_hex_int(devname, "device");

		if (device_id != 0x4000 &&

		    device_id != 0x6000 &&

		    device_id != 0x6003)

			p_info("Unknown NFP device ID, assuming it is NFP-6xxx arch");

		return "NFP-6xxx";

	default:

		p_err("Can't get bfd arch name for device vendor id 0x%04x",

		      vendor_id);

		return NULL;

	}

}



void print_dev_plain(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)

{

	char name[IF_NAMESIZE];

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