strace/bpf.c

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/*
* Copyright (c) 2015-2017 Dmitry V. Levin <ldv@altlinux.org>
* Copyright (c) 2017 Quentin Monnet <quentin.monnet@6wind.com>
* Copyright (c) 2015-2018 The strace developers.
* All rights reserved.
*
* SPDX-License-Identifier: LGPL-2.1-or-later
*/
#include "defs.h"
#include "print_fields.h"
#ifdef HAVE_LINUX_BPF_H
# include <linux/bpf.h>
#endif
#include <linux/filter.h>
#include "bpf_attr.h"
#include "xlat/bpf_commands.h"
#include "xlat/bpf_file_mode_flags.h"
#include "xlat/bpf_map_types.h"
#include "xlat/bpf_map_flags.h"
#include "xlat/bpf_prog_types.h"
#include "xlat/bpf_prog_flags.h"
#include "xlat/bpf_map_update_elem_flags.h"
#include "xlat/bpf_attach_type.h"
#include "xlat/bpf_attach_flags.h"
#include "xlat/bpf_query_flags.h"
#include "xlat/ebpf_regs.h"
#include "xlat/numa_node.h"
#define DECL_BPF_CMD_DECODER(bpf_cmd_decoder) \
int \
bpf_cmd_decoder(struct tcb *const tcp, \
const kernel_ulong_t addr, \
const unsigned int size, \
void *const data) \
/* End of DECL_BPF_CMD_DECODER definition. */
#define BEGIN_BPF_CMD_DECODER(bpf_cmd) \
static DECL_BPF_CMD_DECODER(decode_ ## bpf_cmd) \
{ \
struct bpf_cmd ## _struct attr = {}; \
const size_t attr_size = bpf_cmd ## _struct_size; \
const unsigned int len = MIN(size, attr_size); \
memcpy(&attr, data, len); \
do { \
/* End of BEGIN_BPF_CMD_DECODER definition. */
#define END_BPF_CMD_DECODER(rval) \
decode_attr_extra_data(tcp, data, size, attr_size); \
} while (0); \
tprints("}"); \
return (rval); \
} \
/* End of END_BPF_CMD_DECODER definition. */
#define BPF_CMD_ENTRY(bpf_cmd) \
[bpf_cmd] = decode_ ## bpf_cmd
typedef DECL_BPF_CMD_DECODER((*bpf_cmd_decoder_t));
/*
* A note about bpf syscall decoder: it doesn't perform any size sanity checks,
* so even if it leads to partial copying of one of the fields, the command
* handler will still use the (partially-copied-from-userspace, partially
* zeroed) field value. That's why we stop decoding and check for known sizes
* that correspond to released versions of the structure used by the specific
* command - it looks like the most sensible way to parse this insanity.
*/
static int
decode_attr_extra_data(struct tcb *const tcp,
const char *data,
unsigned int size,
const size_t attr_size)
{
if (size <= attr_size)
return 0;
data += attr_size;
size -= attr_size;
unsigned int i;
for (i = 0; i < size; ++i) {
if (data[i]) {
tprints(", ");
if (abbrev(tcp)) {
tprints("...");
} else {
tprintf("/* bytes %zu..%zu */ ",
attr_size, attr_size + size - 1);
print_quoted_string(data, size,
QUOTE_FORCE_HEX);
}
return RVAL_DECODED;
}
}
return 0;
}
struct ebpf_insn {
uint8_t code;
uint8_t dst_reg:4;
uint8_t src_reg:4;
int16_t off;
int32_t imm;
};
struct ebpf_insns_data {
unsigned int count;
};
static bool
print_ebpf_insn(struct tcb * const tcp, void * const elem_buf,
const size_t elem_size, void * const data)
{
struct ebpf_insns_data *eid = data;
struct ebpf_insn *insn = elem_buf;
if (eid->count++ >= BPF_MAXINSNS) {
tprints("...");
return false;
}
tprints("{code=");
print_bpf_filter_code(insn->code, true);
/* We can't use PRINT_FIELD_XVAL on bit fields */
tprints(", dst_reg=");
printxval_index(ebpf_regs, insn->dst_reg, "BPF_REG_???");
tprints(", src_reg=");
printxval_index(ebpf_regs, insn->src_reg, "BPF_REG_???");
PRINT_FIELD_D(", ", *insn, off);
PRINT_FIELD_X(", ", *insn, imm);
tprints("}");
return true;
}
static void
print_ebpf_prog(struct tcb *const tcp, const uint64_t addr, const uint32_t len)
{
print_big_u64_addr(addr);
if (abbrev(tcp)) {
printaddr(addr);
} else {
struct ebpf_insns_data eid = {};
struct ebpf_insn insn;
print_array(tcp, addr, len, &insn, sizeof(insn),
print_array: enhance printing of unfetchable object addresses When umoven_func invocation fails to fetch data, it prints the faulty address. If this happens to a subsequent umoven_func invocation, the printed address may be undistinguishable from a valid data printed by print_func, e.g. when the data is printed in a numeric form like [0x1, 0x2, 0x3, 0xdefaced]. Fix this source of confusion by moving the printing of the faulty address from umoven_func to print_array itself. This change renames umoven_func to tfetch_mem_func and changes its semantics, so that - tfetch_mem_func never prints anything; - tfetch_mem_func returns true if the fetch succeeded, and false otherwise. * defs.h (print_array): Replace umoven_func argument with tfetch_mem_func. * util.c (print_array): Replace umoven_func argument with tfetch_mem_func, document expected tfetch_mem_func return value semantics. When tfetch_mem_func returns false, print either addr or "... /* addr */" depending on the context (inside the array or not). * bpf.c (print_ebpf_prog, print_bpf_prog_info, BEGIN_BPF_CMD_DECODER(BPF_PROG_QUERY)): Replace umoven_or_printaddr argument of print_array with tfetch_mem. * bpf_filter.c (print_bpf_fprog): Likewise. * btrfs.c (btrfs_print_logical_ino_container, btrfs_print_ino_path_container, btrfs_print_qgroup_inherit, btrfs_ioctl): Likewise. * dm.c (dm_decode_dm_target_deps): Likewise. * epoll.c (epoll_wait_common): Likewise. * file_ioctl.c (file_ioctl): Likewise. * ipc_sem.c (tprint_sembuf_array): Likewise. * kexec.c (print_kexec_segments): Likewise. * mem.c (SYS_FUNC(subpage_prot)): Likewise. * net.c (print_getsockopt): Likewise. * netlink.c (decode_nlmsgerr_attr_cookie): Likewise. * netlink_netlink_diag.c (decode_netlink_diag_groups): Likewise. * netlink_packet_diag.c (decode_packet_diag_mclist): Likewise. * netlink_unix_diag.c (decode_unix_diag_inode): Likewise. * nlattr.c (decode_nla_meminfo): Likewise. * numa.c (print_nodemask, SYS_FUNC(move_pages), * perf_ioctl.c (perf_ioctl_query_bpf): Likewise. * poll.c (decode_poll_entering): Likewise. * printsiginfo.c (print_siginfo_array): Likewise. * rtnl_tc.c (decode_tca_stab_data): Likewise. * sock.c (decode_ifconf): Likewise. * uid.c (print_groups): Likewise. * io.c (SYS_FUNC(io_submit), SYS_FUNC(io_getevents)): Replace umoven_or_printaddr argument of print_array with tfetch_mem. (tprint_iov_upto): Replace umoven_or_printaddr_ignore_syserror with tfetch_mem_ignore_syserror. * v4l2.c (print_v4l2_format_fmt): Replace umoven_or_printaddr argument of print_array with tfetch_mem. (print_v4l2_ext_controls): Replace umoven_or_printaddr_ignore_syserror with tfetch_mem_ignore_syserror. * mmsghdr.c (fetch_struct_mmsghdr_or_printaddr): Rename to fetch_struct_mmsghdr_for_print, do not print address, return bool. (decode_mmsgvec): Replace fetch_struct_mmsghdr_or_printaddr with fetch_struct_mmsghdr_for_print. * tests/aio.c (main): Update expected output. * tests/bpf.c (print_BPF_PROG_QUERY_attr5): Likewise. * tests/ioctl_perf-success.c (main): Likewise. * tests/ioctl_v4l2.c (main): Update expected output. * tests/kexec_load.c (main): Likewise. * tests/mmsg_name.c (test_mmsg_name): Update expected output. * tests/move_pages.c (print_page_array, print_node_array): Likewise. * tests/poll.c (print_pollfd_array_entering): Likewise. * tests/preadv-pwritev.c (main): Likewise. * tests/preadv2-pwritev2.c (dumpio): Likewise. * tests/process_vm_readv_writev.c (print_iov): Likewise. * tests/pwritev.c (print_iovec): Likewise. * tests/readv.c (main): Likewise. * tests/seccomp-filter-v.c * tests/semop.c (main): Likewise. * tests/set_mempolicy.c (print_nodes): Likewise. * tests/setgroups.c (main): Likewise. * tests/test_nlattr.h (print_nlattr) Likewise. Co-Authored-by: Eugene Syromyatnikov <evgsyr@gmail.com>
2018-05-29 04:15:19 +03:00
tfetch_mem, print_ebpf_insn, &eid);
}
}
BEGIN_BPF_CMD_DECODER(BPF_MAP_CREATE)
{
PRINT_FIELD_XVAL_INDEX("{", attr, map_type, bpf_map_types,
"BPF_MAP_TYPE_???");
PRINT_FIELD_U(", ", attr, key_size);
PRINT_FIELD_U(", ", attr, value_size);
PRINT_FIELD_U(", ", attr, max_entries);
/* map_flags field was added in Linux commit v4.6-rc1~91^2~108^2~6. */
if (len <= offsetof(struct BPF_MAP_CREATE_struct, map_flags))
break;
PRINT_FIELD_FLAGS(", ", attr, map_flags, bpf_map_flags, "BPF_F_???");
/*
* inner_map_fd field was added in Linux commit
* v4.12-rc1~64^3~373^2~2.
*/
if (len <= offsetof(struct BPF_MAP_CREATE_struct, inner_map_fd))
break;
PRINT_FIELD_FD(", ", attr, inner_map_fd, tcp);
/* numa_node field was added in Linux commit v4.14-rc1~130^2~196^2~1. */
if (len <= offsetof(struct BPF_MAP_CREATE_struct, numa_node))
break;
if (attr.map_flags & BPF_F_NUMA_NODE) {
/*
* Kernel uses the value of -1 as a designation for "no NUMA
* node specified", and even uses NUMA_NO_NODE constant;
* however, the constant definition is not a part of UAPI
* headers, thus we can't simply print this named constant
* instead of the value. Let's force verbose xlat style instead
* in order to provide the information for the user while
* not hampering the availability to derive the actual value
* without the access to the kernel headers.
*/
tprints(", numa_node=");
printxvals_ex(attr.numa_node, NULL,
XLAT_STYLE_FMT_U | XLAT_STYLE_VERBOSE,
numa_node, NULL);
}
/* map_name field was added in Linux commit v4.15-rc1~84^2~605^2~3. */
if (len <= offsetof(struct BPF_MAP_CREATE_struct, map_name))
break;
PRINT_FIELD_CSTRING_SZ(", ", attr, map_name,
MIN(sizeof(attr.map_name),
len - offsetof(struct BPF_MAP_CREATE_struct,
map_name)));
/*
* map_ifindex field was added in Linux commit
* v4.16-rc1~123^2~145^2~5^2~8.
*/
if (len <= offsetof(struct BPF_MAP_CREATE_struct, map_ifindex))
break;
PRINT_FIELD_IFINDEX(", ", attr, map_ifindex);
}
END_BPF_CMD_DECODER(RVAL_DECODED | RVAL_FD)
BEGIN_BPF_CMD_DECODER(BPF_MAP_LOOKUP_ELEM)
{
PRINT_FIELD_FD("{", attr, map_fd, tcp);
PRINT_FIELD_ADDR64(", ", attr, key);
PRINT_FIELD_ADDR64(", ", attr, value);
}
END_BPF_CMD_DECODER(RVAL_DECODED)
BEGIN_BPF_CMD_DECODER(BPF_MAP_UPDATE_ELEM)
{
PRINT_FIELD_FD("{", attr, map_fd, tcp);
PRINT_FIELD_ADDR64(", ", attr, key);
PRINT_FIELD_ADDR64(", ", attr, value);
PRINT_FIELD_XVAL_INDEX(", ", attr, flags, bpf_map_update_elem_flags,
"BPF_???");
}
END_BPF_CMD_DECODER(RVAL_DECODED)
BEGIN_BPF_CMD_DECODER(BPF_MAP_DELETE_ELEM)
{
PRINT_FIELD_FD("{", attr, map_fd, tcp);
PRINT_FIELD_ADDR64(", ", attr, key);
}
END_BPF_CMD_DECODER(RVAL_DECODED)
BEGIN_BPF_CMD_DECODER(BPF_MAP_GET_NEXT_KEY)
{
PRINT_FIELD_FD("{", attr, map_fd, tcp);
PRINT_FIELD_ADDR64(", ", attr, key);
PRINT_FIELD_ADDR64(", ", attr, next_key);
}
END_BPF_CMD_DECODER(RVAL_DECODED)
BEGIN_BPF_CMD_DECODER(BPF_PROG_LOAD)
{
PRINT_FIELD_XVAL_INDEX("{", attr, prog_type, bpf_prog_types,
"BPF_PROG_TYPE_???");
PRINT_FIELD_U(", ", attr, insn_cnt);
tprints(", insns=");
print_ebpf_prog(tcp, attr.insns, attr.insn_cnt);
tprintf(", license=");
print_big_u64_addr(attr.license);
printstr(tcp, attr.license);
/* log_* fields were added in Linux commit v3.18-rc1~52^2~1^2~4. */
if (len <= offsetof(struct BPF_PROG_LOAD_struct, log_level))
break;
PRINT_FIELD_U(", ", attr, log_level);
PRINT_FIELD_U(", ", attr, log_size);
tprintf(", log_buf=");
print_big_u64_addr(attr.log_buf);
printstr_ex(tcp, attr.log_buf, attr.log_size, QUOTE_0_TERMINATED);
/* kern_version field was added in Linux commit v4.1-rc1~84^2~50. */
if (len <= offsetof(struct BPF_PROG_LOAD_struct, kern_version))
break;
tprints(", kern_version=");
print_kernel_version(attr.kern_version);
/* prog_flags field was added in Linux commit v4.12-rc2~34^2~29^2~2. */
if (len <= offsetof(struct BPF_PROG_LOAD_struct, prog_flags))
break;
PRINT_FIELD_FLAGS(", ", attr, prog_flags, bpf_prog_flags, "BPF_F_???");
/* prog_name field was added in Linux commit v4.15-rc1~84^2~605^2~4. */
if (len <= offsetof(struct BPF_PROG_LOAD_struct, prog_name))
break;
PRINT_FIELD_CSTRING_SZ(", ", attr, prog_name,
MIN(sizeof(attr.prog_name),
len - offsetof(struct BPF_PROG_LOAD_struct,
prog_name)));
/*
* prog_ifindex field was added as prog_target_ifindex in Linux commit
* v4.15-rc1~84^2~127^2~13 and renamed to its current name in
* v4.15-rc1~15^2~5^2~3^2~7.
*/
if (len <= offsetof(struct BPF_PROG_LOAD_struct, prog_ifindex))
break;
PRINT_FIELD_IFINDEX(", ", attr, prog_ifindex);
/*
* expected_attach_type was added in Linux commit
* v4.17-rc1~148^2~19^2^2~8.
*/
if (len <= offsetof(struct BPF_PROG_LOAD_struct, expected_attach_type))
break;
PRINT_FIELD_XVAL(", ", attr, expected_attach_type, bpf_attach_type,
"BPF_???");
}
END_BPF_CMD_DECODER(RVAL_DECODED | RVAL_FD)
BEGIN_BPF_CMD_DECODER(BPF_OBJ_PIN)
{
tprintf("{pathname=");
print_big_u64_addr(attr.pathname);
printpath(tcp, attr.pathname);
PRINT_FIELD_FD(", ", attr, bpf_fd, tcp);
/* file_flags field was added in Linux v4.15-rc1~84^2~384^2~4 */
if (len <= offsetof(struct BPF_OBJ_PIN_struct, file_flags))
break;
PRINT_FIELD_FLAGS(", ", attr, file_flags, bpf_file_mode_flags,
"BPF_F_???");
}
END_BPF_CMD_DECODER(RVAL_DECODED | RVAL_FD)
#define decode_BPF_OBJ_GET decode_BPF_OBJ_PIN
BEGIN_BPF_CMD_DECODER(BPF_PROG_ATTACH)
{
PRINT_FIELD_FD("{", attr, target_fd, tcp);
PRINT_FIELD_FD(", ", attr, attach_bpf_fd, tcp);
PRINT_FIELD_XVAL_INDEX(", ", attr, attach_type, bpf_attach_type,
"BPF_???");
PRINT_FIELD_FLAGS(", ", attr, attach_flags, bpf_attach_flags,
"BPF_F_???");
}
END_BPF_CMD_DECODER(RVAL_DECODED)
BEGIN_BPF_CMD_DECODER(BPF_PROG_DETACH)
{
PRINT_FIELD_FD("{", attr, target_fd, tcp);
PRINT_FIELD_XVAL_INDEX(", ", attr, attach_type, bpf_attach_type,
"BPF_???");
}
END_BPF_CMD_DECODER(RVAL_DECODED)
BEGIN_BPF_CMD_DECODER(BPF_PROG_TEST_RUN)
{
PRINT_FIELD_FD("{test={", attr, prog_fd, tcp);
PRINT_FIELD_U(", ", attr, retval);
PRINT_FIELD_U(", ", attr, data_size_in);
PRINT_FIELD_U(", ", attr, data_size_out);
PRINT_FIELD_ADDR64(", ", attr, data_in);
PRINT_FIELD_ADDR64(", ", attr, data_out);
PRINT_FIELD_U(", ", attr, repeat);
PRINT_FIELD_U(", ", attr, duration);
tprints("}");
}
END_BPF_CMD_DECODER(RVAL_DECODED)
BEGIN_BPF_CMD_DECODER(BPF_PROG_GET_NEXT_ID)
{
PRINT_FIELD_U("{", attr, start_id);
PRINT_FIELD_U(", ", attr, next_id);
/* open_flags field has been added in Linux v4.15-rc1~84^2~384^2~4 */
if (len <= offsetof(struct BPF_PROG_GET_NEXT_ID_struct, open_flags))
break;
PRINT_FIELD_FLAGS(", ", attr, open_flags, bpf_file_mode_flags,
"BPF_F_???");
}
END_BPF_CMD_DECODER(RVAL_DECODED)
#define decode_BPF_MAP_GET_NEXT_ID decode_BPF_PROG_GET_NEXT_ID
BEGIN_BPF_CMD_DECODER(BPF_PROG_GET_FD_BY_ID)
{
PRINT_FIELD_U("{", attr, prog_id);
PRINT_FIELD_U(", ", attr, next_id);
/* open_flags field has been added in Linux v4.15-rc1~84^2~384^2~4 */
if (len <= offsetof(struct BPF_PROG_GET_FD_BY_ID_struct, open_flags))
break;
PRINT_FIELD_FLAGS(", ", attr, open_flags, bpf_file_mode_flags,
"BPF_F_???");
}
END_BPF_CMD_DECODER(RVAL_DECODED)
BEGIN_BPF_CMD_DECODER(BPF_MAP_GET_FD_BY_ID)
{
PRINT_FIELD_U("{", attr, map_id);
PRINT_FIELD_U(", ", attr, next_id);
/* open_flags field has been added in Linux v4.15-rc1~84^2~384^2~4 */
if (len <= offsetof(struct BPF_MAP_GET_FD_BY_ID_struct, open_flags))
break;
PRINT_FIELD_FLAGS(", ", attr, open_flags, bpf_file_mode_flags,
"BPF_F_???");
}
END_BPF_CMD_DECODER(RVAL_DECODED)
struct obj_get_info_saved;
typedef void (*print_bpf_obj_info_fn)(struct tcb *,
uint32_t bpf_fd,
const char *info_buf,
uint32_t size,
struct obj_get_info_saved *saved);
struct obj_get_info_saved {
print_bpf_obj_info_fn print_fn;
uint32_t info_len;
uint32_t jited_prog_len;
uint32_t xlated_prog_len;
uint32_t nr_map_ids;
};
static void
print_bpf_map_info(struct tcb * const tcp, uint32_t bpf_fd,
const char *info_buf, uint32_t size,
struct obj_get_info_saved *saved)
{
if (entering(tcp))
return;
struct bpf_map_info_struct info = { 0 };
const unsigned int len = MIN(size, bpf_map_info_struct_size);
memcpy(&info, info_buf, len);
PRINT_FIELD_XVAL("{", info, type, bpf_map_types, "BPF_MAP_TYPE_???");
PRINT_FIELD_U(", ", info, id);
PRINT_FIELD_U(", ", info, key_size);
PRINT_FIELD_U(", ", info, value_size);
PRINT_FIELD_U(", ", info, max_entries);
PRINT_FIELD_FLAGS(", ", info, map_flags, bpf_map_flags, "BPF_F_???");
/*
* "name" field was introduced by Linux commit v4.15-rc1~84^2~605^2~3.
*/
if (len <= offsetof(struct bpf_map_info_struct, name))
goto print_bpf_map_info_end;
PRINT_FIELD_CSTRING(", ", info, name);
/*
* ifindex, netns_dev, and netns_ino fields were introduced
* by Linux commit v4.16-rc1~123^2~109^2~5^2~4.
*/
if (len <= offsetof(struct bpf_map_info_struct, ifindex))
goto print_bpf_map_info_end;
PRINT_FIELD_IFINDEX(", ", info, ifindex);
PRINT_FIELD_DEV(", ", info, netns_dev);
PRINT_FIELD_U(", ", info, netns_ino);
decode_attr_extra_data(tcp, info_buf, size, bpf_map_info_struct_size);
print_bpf_map_info_end:
tprints("}");
}
static void
print_bpf_prog_info(struct tcb * const tcp, uint32_t bpf_fd,
const char *info_buf, uint32_t size,
struct obj_get_info_saved *saved)
{
struct bpf_prog_info_struct info = { 0 };
const unsigned int len = MIN(size, bpf_prog_info_struct_size);
uint64_t map_id_buf;
memcpy(&info, info_buf, len);
if (entering(tcp)) {
saved->jited_prog_len = info.jited_prog_len;
saved->xlated_prog_len = info.xlated_prog_len;
saved->nr_map_ids = info.nr_map_ids;
return;
}
PRINT_FIELD_XVAL("{", info, type, bpf_prog_types, "BPF_PROG_TYPE_???");
PRINT_FIELD_U(", ", info, id);
PRINT_FIELD_HEX_ARRAY(", ", info, tag);
tprints(", jited_prog_len=");
if (saved->jited_prog_len != info.jited_prog_len)
tprintf("%" PRIu32 " => ", saved->jited_prog_len);
tprintf("%" PRIu32, info.jited_prog_len);
tprints(", jited_prog_insns=");
print_big_u64_addr(info.jited_prog_insns);
printstr_ex(tcp, info.jited_prog_insns, info.jited_prog_len,
QUOTE_FORCE_HEX);
tprints(", xlated_prog_len=");
if (saved->xlated_prog_len != info.xlated_prog_len)
tprintf("%" PRIu32 " => ", saved->xlated_prog_len);
tprintf("%" PRIu32, info.xlated_prog_len);
tprints(", xlated_prog_insns=");
print_ebpf_prog(tcp, info.xlated_prog_insns,
MIN(saved->xlated_prog_len, info.xlated_prog_len) / 8);
/*
* load_time, created_by_uid, nr_map_ids, map_ids, and name fields
* were introduced by Linux commit v4.15-rc1~84^2~605^2~4.
*/
if (len <= offsetof(struct bpf_prog_info_struct, load_time))
goto print_bpf_prog_info_end;
PRINT_FIELD_U(", ", info, load_time);
PRINT_FIELD_UID(", ", info, created_by_uid);
tprints(", nr_map_ids=");
if (saved->nr_map_ids != info.nr_map_ids)
tprintf("%" PRIu32 " => ", saved->nr_map_ids);
tprintf("%" PRIu32, info.nr_map_ids);
tprints(", map_ids=");
print_big_u64_addr(info.map_ids);
print_array(tcp, info.map_ids, MIN(saved->nr_map_ids, info.nr_map_ids),
&map_id_buf, sizeof(map_id_buf),
tfetch_mem, print_uint32_array_member, 0);
PRINT_FIELD_CSTRING(", ", info, name);
/*
* ifindex, netns_dev, and netns_ino fields were introduced
* by Linux commit v4.16-rc1~123^2~227^2~5^2~2.
*/
if (len <= offsetof(struct bpf_prog_info_struct, ifindex))
goto print_bpf_prog_info_end;
PRINT_FIELD_IFINDEX(", ", info, ifindex);
PRINT_FIELD_DEV(", ", info, netns_dev);
PRINT_FIELD_U(", ", info, netns_ino);
decode_attr_extra_data(tcp, info_buf, size, bpf_prog_info_struct_size);
print_bpf_prog_info_end:
tprints("}");
}
static const char *
fetch_bpf_obj_info(struct tcb * const tcp, uint64_t info, uint32_t size)
{
static char *info_buf;
if (!info_buf)
info_buf = xmalloc(get_pagesize());
memset(info_buf, 0, get_pagesize());
if (size > 0 && size <= get_pagesize()
&& !umoven(tcp, info, size, info_buf))
return info_buf;
return NULL;
}
static void
print_bpf_obj_info_addr(struct tcb * const tcp, uint64_t addr)
{
if (exiting(tcp))
printaddr64(addr);
}
static void
print_bpf_obj_info(struct tcb * const tcp, uint32_t bpf_fd, uint64_t info,
uint32_t size, struct obj_get_info_saved *saved)
{
if (abbrev(tcp)) {
print_bpf_obj_info_addr(tcp, info);
return;
}
static struct {
const char *id;
print_bpf_obj_info_fn print_fn;
} obj_printers[] = {
{ "anon_inode:bpf-map", print_bpf_map_info },
{ "anon_inode:bpf-prog", print_bpf_prog_info }
};
if (entering(tcp)) {
char path[PATH_MAX + 1];
if (getfdpath(tcp, bpf_fd, path, sizeof(path)) > 0) {
for (size_t i = 0; i < ARRAY_SIZE(obj_printers); ++i) {
if (!strcmp(path, obj_printers[i].id)) {
saved->print_fn =
obj_printers[i].print_fn;
break;
}
}
}
}
if (!saved || !saved->print_fn) {
print_bpf_obj_info_addr(tcp, info);
return;
}
const char *info_buf = fetch_bpf_obj_info(tcp, info, size);
if (info_buf)
saved->print_fn(tcp, bpf_fd, info_buf, size, saved);
else
print_bpf_obj_info_addr(tcp, info);
}
BEGIN_BPF_CMD_DECODER(BPF_OBJ_GET_INFO_BY_FD)
{
struct obj_get_info_saved *saved;
if (entering(tcp)) {
saved = xcalloc(1, sizeof(*saved));
saved->info_len = attr.info_len;
set_tcb_priv_data(tcp, saved, free);
PRINT_FIELD_FD("{info={", attr, bpf_fd, tcp);
PRINT_FIELD_U(", ", attr, info_len);
} else {
saved = get_tcb_priv_data(tcp);
if (saved && (saved->info_len != attr.info_len))
tprintf(" => %u", attr.info_len);
tprintf(", info=");
}
print_bpf_obj_info(tcp, attr.bpf_fd, attr.info, attr.info_len, saved);
if (entering(tcp))
return 0;
tprints("}");
}
END_BPF_CMD_DECODER(RVAL_DECODED)
BEGIN_BPF_CMD_DECODER(BPF_PROG_QUERY)
{
uint32_t prog_id_buf;
if (entering(tcp)) {
PRINT_FIELD_FD("{query={", attr, target_fd, tcp);
PRINT_FIELD_XVAL_INDEX(", ", attr, attach_type, bpf_attach_type,
"BPF_???");
PRINT_FIELD_FLAGS(", ", attr, query_flags, bpf_query_flags,
"BPF_F_QUERY_???");
PRINT_FIELD_FLAGS(", ", attr, attach_flags, bpf_attach_flags,
"BPF_F_???");
tprints(", prog_ids=");
set_tcb_priv_ulong(tcp, attr.prog_cnt);
return 0;
}
print_big_u64_addr(attr.prog_ids);
print_array(tcp, attr.prog_ids, attr.prog_cnt, &prog_id_buf,
print_array: enhance printing of unfetchable object addresses When umoven_func invocation fails to fetch data, it prints the faulty address. If this happens to a subsequent umoven_func invocation, the printed address may be undistinguishable from a valid data printed by print_func, e.g. when the data is printed in a numeric form like [0x1, 0x2, 0x3, 0xdefaced]. Fix this source of confusion by moving the printing of the faulty address from umoven_func to print_array itself. This change renames umoven_func to tfetch_mem_func and changes its semantics, so that - tfetch_mem_func never prints anything; - tfetch_mem_func returns true if the fetch succeeded, and false otherwise. * defs.h (print_array): Replace umoven_func argument with tfetch_mem_func. * util.c (print_array): Replace umoven_func argument with tfetch_mem_func, document expected tfetch_mem_func return value semantics. When tfetch_mem_func returns false, print either addr or "... /* addr */" depending on the context (inside the array or not). * bpf.c (print_ebpf_prog, print_bpf_prog_info, BEGIN_BPF_CMD_DECODER(BPF_PROG_QUERY)): Replace umoven_or_printaddr argument of print_array with tfetch_mem. * bpf_filter.c (print_bpf_fprog): Likewise. * btrfs.c (btrfs_print_logical_ino_container, btrfs_print_ino_path_container, btrfs_print_qgroup_inherit, btrfs_ioctl): Likewise. * dm.c (dm_decode_dm_target_deps): Likewise. * epoll.c (epoll_wait_common): Likewise. * file_ioctl.c (file_ioctl): Likewise. * ipc_sem.c (tprint_sembuf_array): Likewise. * kexec.c (print_kexec_segments): Likewise. * mem.c (SYS_FUNC(subpage_prot)): Likewise. * net.c (print_getsockopt): Likewise. * netlink.c (decode_nlmsgerr_attr_cookie): Likewise. * netlink_netlink_diag.c (decode_netlink_diag_groups): Likewise. * netlink_packet_diag.c (decode_packet_diag_mclist): Likewise. * netlink_unix_diag.c (decode_unix_diag_inode): Likewise. * nlattr.c (decode_nla_meminfo): Likewise. * numa.c (print_nodemask, SYS_FUNC(move_pages), * perf_ioctl.c (perf_ioctl_query_bpf): Likewise. * poll.c (decode_poll_entering): Likewise. * printsiginfo.c (print_siginfo_array): Likewise. * rtnl_tc.c (decode_tca_stab_data): Likewise. * sock.c (decode_ifconf): Likewise. * uid.c (print_groups): Likewise. * io.c (SYS_FUNC(io_submit), SYS_FUNC(io_getevents)): Replace umoven_or_printaddr argument of print_array with tfetch_mem. (tprint_iov_upto): Replace umoven_or_printaddr_ignore_syserror with tfetch_mem_ignore_syserror. * v4l2.c (print_v4l2_format_fmt): Replace umoven_or_printaddr argument of print_array with tfetch_mem. (print_v4l2_ext_controls): Replace umoven_or_printaddr_ignore_syserror with tfetch_mem_ignore_syserror. * mmsghdr.c (fetch_struct_mmsghdr_or_printaddr): Rename to fetch_struct_mmsghdr_for_print, do not print address, return bool. (decode_mmsgvec): Replace fetch_struct_mmsghdr_or_printaddr with fetch_struct_mmsghdr_for_print. * tests/aio.c (main): Update expected output. * tests/bpf.c (print_BPF_PROG_QUERY_attr5): Likewise. * tests/ioctl_perf-success.c (main): Likewise. * tests/ioctl_v4l2.c (main): Update expected output. * tests/kexec_load.c (main): Likewise. * tests/mmsg_name.c (test_mmsg_name): Update expected output. * tests/move_pages.c (print_page_array, print_node_array): Likewise. * tests/poll.c (print_pollfd_array_entering): Likewise. * tests/preadv-pwritev.c (main): Likewise. * tests/preadv2-pwritev2.c (dumpio): Likewise. * tests/process_vm_readv_writev.c (print_iov): Likewise. * tests/pwritev.c (print_iovec): Likewise. * tests/readv.c (main): Likewise. * tests/seccomp-filter-v.c * tests/semop.c (main): Likewise. * tests/set_mempolicy.c (print_nodes): Likewise. * tests/setgroups.c (main): Likewise. * tests/test_nlattr.h (print_nlattr) Likewise. Co-Authored-by: Eugene Syromyatnikov <evgsyr@gmail.com>
2018-05-29 04:15:19 +03:00
sizeof(prog_id_buf), tfetch_mem,
print_uint32_array_member, 0);
tprints(", prog_cnt=");
const uint32_t prog_cnt_entering = get_tcb_priv_ulong(tcp);
if (prog_cnt_entering != attr.prog_cnt)
tprintf("%" PRIu32 " => ", prog_cnt_entering);
tprintf("%" PRIu32, attr.prog_cnt);
tprints("}");
}
END_BPF_CMD_DECODER(RVAL_DECODED)
BEGIN_BPF_CMD_DECODER(BPF_RAW_TRACEPOINT_OPEN)
{
enum { TP_NAME_SIZE = 128 };
tprintf("{raw_tracepoint={name=");
print_big_u64_addr(attr.name);
printstr_ex(tcp, attr.name, TP_NAME_SIZE, QUOTE_0_TERMINATED);
PRINT_FIELD_FD(", ", attr, prog_fd, tcp);
tprints("}");
}
END_BPF_CMD_DECODER(RVAL_DECODED)
SYS_FUNC(bpf)
{
static const bpf_cmd_decoder_t bpf_cmd_decoders[] = {
BPF_CMD_ENTRY(BPF_MAP_CREATE),
BPF_CMD_ENTRY(BPF_MAP_LOOKUP_ELEM),
BPF_CMD_ENTRY(BPF_MAP_UPDATE_ELEM),
BPF_CMD_ENTRY(BPF_MAP_DELETE_ELEM),
BPF_CMD_ENTRY(BPF_MAP_GET_NEXT_KEY),
BPF_CMD_ENTRY(BPF_PROG_LOAD),
BPF_CMD_ENTRY(BPF_OBJ_PIN),
BPF_CMD_ENTRY(BPF_OBJ_GET),
BPF_CMD_ENTRY(BPF_PROG_ATTACH),
BPF_CMD_ENTRY(BPF_PROG_DETACH),
BPF_CMD_ENTRY(BPF_PROG_TEST_RUN),
BPF_CMD_ENTRY(BPF_PROG_GET_NEXT_ID),
BPF_CMD_ENTRY(BPF_MAP_GET_NEXT_ID),
BPF_CMD_ENTRY(BPF_PROG_GET_FD_BY_ID),
BPF_CMD_ENTRY(BPF_MAP_GET_FD_BY_ID),
BPF_CMD_ENTRY(BPF_OBJ_GET_INFO_BY_FD),
BPF_CMD_ENTRY(BPF_PROG_QUERY),
BPF_CMD_ENTRY(BPF_RAW_TRACEPOINT_OPEN),
};
const unsigned int cmd = tcp->u_arg[0];
const kernel_ulong_t addr = tcp->u_arg[1];
const unsigned int size = tcp->u_arg[2];
int rc = RVAL_DECODED;
if (entering(tcp)) {
printxval_index(bpf_commands, cmd, "BPF_???");
tprints(", ");
}
if (size > 0
&& size <= get_pagesize()
&& cmd < ARRAY_SIZE(bpf_cmd_decoders)
&& bpf_cmd_decoders[cmd]) {
static char *buf;
if (!buf)
buf = xmalloc(get_pagesize());
if (!umoven_or_printaddr_ignore_syserror(tcp, addr, size, buf))
rc = bpf_cmd_decoders[cmd](tcp, addr, size, buf);
} else {
printaddr(addr);
}
if (exiting(tcp) || (rc & RVAL_DECODED))
tprintf(", %u", size);
return rc;
}