tools: bpftool: improve architecture detection by using ifindex
authorJiong Wang <jiong.wang@netronome.com>
Wed, 17 Jan 2018 00:05:21 +0000 (16:05 -0800)
committerDaniel Borkmann <daniel@iogearbox.net>
Thu, 18 Jan 2018 00:26:15 +0000 (01:26 +0100)
The current architecture detection method in bpftool is designed for host
case.

For offload case, we can't use the architecture of "bpftool" itself.
Instead, we could call the existing "ifindex_to_name_ns" to get DEVNAME,
then read pci id from /sys/class/dev/DEVNAME/device/vendor, finally we map
vendor id to bfd arch name which will finally be used to select bfd backend
for the disassembler.

Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
tools/bpf/bpftool/common.c
tools/bpf/bpftool/jit_disasm.c
tools/bpf/bpftool/main.h
tools/bpf/bpftool/prog.c

index 6601c95a9258e8370752f756774b08120dbe5c3c..0b482c0070e04fb06b65eb503959afc06170b472 100644 (file)
@@ -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];
index 57d32e8a13910ebdcbce3266f8127769fadfe980..87439320ef70e1ce5f17d437ff1d882897ccab78 100644 (file)
@@ -76,7 +76,8 @@ static int fprintf_json(void *out, const char *fmt, ...)
        return 0;
 }
 
-void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes)
+void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes,
+                      const char *arch)
 {
        disassembler_ftype disassemble;
        struct disassemble_info info;
@@ -100,6 +101,19 @@ void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes)
        else
                init_disassemble_info(&info, stdout,
                                      (fprintf_ftype) fprintf);
+
+       /* Update architecture info for offload. */
+       if (arch) {
+               const bfd_arch_info_type *inf = bfd_scan_arch(arch);
+
+               if (inf) {
+                       bfdf->arch_info = inf;
+               } else {
+                       p_err("No libfd support for %s", arch);
+                       return;
+               }
+       }
+
        info.arch = bfd_get_arch(bfdf);
        info.mach = bfd_get_mach(bfdf);
        info.buffer = image;
index 65b526fe6e7e984c960754761d42deb8f48528c7..b8e9584d624647e733195f753b48f28cc54e84e5 100644 (file)
@@ -121,7 +121,10 @@ int do_cgroup(int argc, char **arg);
 
 int prog_parse_fd(int *argc, char ***argv);
 
-void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes);
+void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes,
+                      const char *arch);
 void print_hex_data_json(uint8_t *data, size_t len);
 
+const char *ifindex_to_bfd_name_ns(__u32 ifindex, __u64 ns_dev, __u64 ns_ino);
+
 #endif
index 099e21cf1b5c7e5f5287890815e9265815541166..e8e2baaf93c2665c4a7cf998a85e35eda76b009d 100644 (file)
@@ -776,7 +776,17 @@ static int do_dump(int argc, char **argv)
                }
        } else {
                if (member_len == &info.jited_prog_len) {
-                       disasm_print_insn(buf, *member_len, opcodes);
+                       const char *name = NULL;
+
+                       if (info.ifindex) {
+                               name = ifindex_to_bfd_name_ns(info.ifindex,
+                                                             info.netns_dev,
+                                                             info.netns_ino);
+                               if (!name)
+                                       goto err_free;
+                       }
+
+                       disasm_print_insn(buf, *member_len, opcodes, name);
                } else {
                        kernel_syms_load(&dd);
                        if (json_output)