target/linux/generic/backport-5.15/060-v5.18-02-bpf-selftests-Remove-libcap-usage-from-test_verifier.patch

   1 From 847a6b7ee906be874f0cae279c8de902a7d3f092 Mon Sep 17 00:00:00 2001
   2 From: Martin KaFai Lau <kafai@fb.com>
   3 Date: Wed, 16 Mar 2022 10:38:29 -0700
   4 Subject: [PATCH 2/3] bpf: selftests: Remove libcap usage from test_verifier
   5
   6 This patch removes the libcap usage from test_verifier.
   7 The cap_*_effective() helpers added in the earlier patch are
   8 used instead.
   9
  10 Signed-off-by: Martin KaFai Lau <kafai@fb.com>
  11 Signed-off-by: Alexei Starovoitov <ast@kernel.org>
  12 Acked-by: John Fastabend <john.fastabend@gmail.com>
  13 Link: https://lore.kernel.org/bpf/20220316173829.2038682-1-kafai@fb.com
  14 ---
  15  tools/testing/selftests/bpf/Makefile        | 31 +++++---
  16  tools/testing/selftests/bpf/test_verifier.c | 88 ++++++---------------
  17  2 files changed, 46 insertions(+), 73 deletions(-)
  18
  19 --- a/tools/testing/selftests/bpf/Makefile
  20 +++ b/tools/testing/selftests/bpf/Makefile
  21 @@ -189,16 +189,27 @@ TEST_GEN_PROGS_EXTENDED += $(DEFAULT_BPF
  22
  23  $(TEST_GEN_PROGS) $(TEST_GEN_PROGS_EXTENDED): $(OUTPUT)/test_stub.o $(BPFOBJ)
  24
  25 -$(OUTPUT)/test_dev_cgroup: cgroup_helpers.c
  26 -$(OUTPUT)/test_skb_cgroup_id_user: cgroup_helpers.c
  27 -$(OUTPUT)/test_sock: cgroup_helpers.c
  28 -$(OUTPUT)/test_sock_addr: cgroup_helpers.c
  29 -$(OUTPUT)/test_sockmap: cgroup_helpers.c
  30 -$(OUTPUT)/test_tcpnotify_user: cgroup_helpers.c trace_helpers.c
  31 -$(OUTPUT)/get_cgroup_id_user: cgroup_helpers.c
  32 -$(OUTPUT)/test_cgroup_storage: cgroup_helpers.c
  33 -$(OUTPUT)/test_sock_fields: cgroup_helpers.c
  34 -$(OUTPUT)/test_sysctl: cgroup_helpers.c
  35 +CGROUP_HELPERS := $(OUTPUT)/cgroup_helpers.o
  36 +TESTING_HELPERS        := $(OUTPUT)/testing_helpers.o
  37 +TRACE_HELPERS  := $(OUTPUT)/trace_helpers.o
  38 +CAP_HELPERS    := $(OUTPUT)/cap_helpers.o
  39 +
  40 +$(OUTPUT)/test_dev_cgroup: $(CGROUP_HELPERS) $(TESTING_HELPERS)
  41 +$(OUTPUT)/test_skb_cgroup_id_user: $(CGROUP_HELPERS) $(TESTING_HELPERS)
  42 +$(OUTPUT)/test_sock: $(CGROUP_HELPERS) $(TESTING_HELPERS)
  43 +$(OUTPUT)/test_sock_addr: $(CGROUP_HELPERS) $(TESTING_HELPERS)
  44 +$(OUTPUT)/test_sockmap: $(CGROUP_HELPERS) $(TESTING_HELPERS)
  45 +$(OUTPUT)/test_tcpnotify_user: $(CGROUP_HELPERS) $(TESTING_HELPERS) $(TRACE_HELPERS)
  46 +$(OUTPUT)/get_cgroup_id_user: $(CGROUP_HELPERS) $(TESTING_HELPERS)
  47 +$(OUTPUT)/test_cgroup_storage: $(CGROUP_HELPERS) $(TESTING_HELPERS)
  48 +$(OUTPUT)/test_sock_fields: $(CGROUP_HELPERS) $(TESTING_HELPERS)
  49 +$(OUTPUT)/test_sysctl: $(CGROUP_HELPERS) $(TESTING_HELPERS)
  50 +$(OUTPUT)/test_tag: $(TESTING_HELPERS)
  51 +$(OUTPUT)/test_lirc_mode2_user: $(TESTING_HELPERS)
  52 +$(OUTPUT)/xdping: $(TESTING_HELPERS)
  53 +$(OUTPUT)/flow_dissector_load: $(TESTING_HELPERS)
  54 +$(OUTPUT)/test_maps: $(TESTING_HELPERS)
  55 +$(OUTPUT)/test_verifier: $(TESTING_HELPERS) $(CAP_HELPERS)
  56
  57  BPFTOOL ?= $(DEFAULT_BPFTOOL)
  58  $(DEFAULT_BPFTOOL): $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile)    \
  59 --- a/tools/testing/selftests/bpf/test_verifier.c
  60 +++ b/tools/testing/selftests/bpf/test_verifier.c
  61 @@ -22,8 +22,6 @@
  62  #include <limits.h>
  63  #include <assert.h>
  64
  65 -#include <sys/capability.h>
  66 -
  67  #include <linux/unistd.h>
  68  #include <linux/filter.h>
  69  #include <linux/bpf_perf_event.h>
  70 @@ -43,6 +41,7 @@
  71  # endif
  72  #endif
  73  #include "bpf_rlimit.h"
  74 +#include "cap_helpers.h"
  75  #include "bpf_rand.h"
  76  #include "bpf_util.h"
  77  #include "test_btf.h"
  78 @@ -59,6 +58,10 @@
  79  #define F_NEEDS_EFFICIENT_UNALIGNED_ACCESS     (1 << 0)
  80  #define F_LOAD_WITH_STRICT_ALIGNMENT           (1 << 1)
  81
  82 +/* need CAP_BPF, CAP_NET_ADMIN, CAP_PERFMON to load progs */
  83 +#define ADMIN_CAPS (1ULL << CAP_NET_ADMIN |    \
  84 +                   1ULL << CAP_PERFMON |       \
  85 +                   1ULL << CAP_BPF)
  86  #define UNPRIV_SYSCTL "kernel/unprivileged_bpf_disabled"
  87  static bool unpriv_disabled = false;
  88  static int skips;
  89 @@ -940,47 +943,19 @@ struct libcap {
  90
  91  static int set_admin(bool admin)
  92  {
  93 -       cap_t caps;
  94 -       /* need CAP_BPF, CAP_NET_ADMIN, CAP_PERFMON to load progs */
  95 -       const cap_value_t cap_net_admin = CAP_NET_ADMIN;
  96 -       const cap_value_t cap_sys_admin = CAP_SYS_ADMIN;
  97 -       struct libcap *cap;
  98 -       int ret = -1;
  99 -
 100 -       caps = cap_get_proc();
 101 -       if (!caps) {
 102 -               perror("cap_get_proc");
 103 -               return -1;
 104 -       }
 105 -       cap = (struct libcap *)caps;
 106 -       if (cap_set_flag(caps, CAP_EFFECTIVE, 1, &cap_sys_admin, CAP_CLEAR)) {
 107 -               perror("cap_set_flag clear admin");
 108 -               goto out;
 109 -       }
 110 -       if (cap_set_flag(caps, CAP_EFFECTIVE, 1, &cap_net_admin,
 111 -                               admin ? CAP_SET : CAP_CLEAR)) {
 112 -               perror("cap_set_flag set_or_clear net");
 113 -               goto out;
 114 -       }
 115 -       /* libcap is likely old and simply ignores CAP_BPF and CAP_PERFMON,
 116 -        * so update effective bits manually
 117 -        */
 118 +       int err;
 119 +
 120         if (admin) {
 121 -               cap->data[1].effective |= 1 << (38 /* CAP_PERFMON */ - 32);
 122 -               cap->data[1].effective |= 1 << (39 /* CAP_BPF */ - 32);
 123 +               err = cap_enable_effective(ADMIN_CAPS, NULL);
 124 +               if (err)
 125 +                       perror("cap_enable_effective(ADMIN_CAPS)");
 126         } else {
 127 -               cap->data[1].effective &= ~(1 << (38 - 32));
 128 -               cap->data[1].effective &= ~(1 << (39 - 32));
 129 +               err = cap_disable_effective(ADMIN_CAPS, NULL);
 130 +               if (err)
 131 +                       perror("cap_disable_effective(ADMIN_CAPS)");
 132         }
 133 -       if (cap_set_proc(caps)) {
 134 -               perror("cap_set_proc");
 135 -               goto out;
 136 -       }
 137 -       ret = 0;
 138 -out:
 139 -       if (cap_free(caps))
 140 -               perror("cap_free");
 141 -       return ret;
 142 +
 143 +       return err;
 144  }
 145
 146  static int do_prog_test_run(int fd_prog, bool unpriv, uint32_t expected_val,
 147 @@ -1246,31 +1221,18 @@ fail_log:
 148
 149  static bool is_admin(void)
 150  {
 151 -       cap_flag_value_t net_priv = CAP_CLEAR;
 152 -       bool perfmon_priv = false;
 153 -       bool bpf_priv = false;
 154 -       struct libcap *cap;
 155 -       cap_t caps;
 156 -
 157 -#ifdef CAP_IS_SUPPORTED
 158 -       if (!CAP_IS_SUPPORTED(CAP_SETFCAP)) {
 159 -               perror("cap_get_flag");
 160 -               return false;
 161 -       }
 162 -#endif
 163 -       caps = cap_get_proc();
 164 -       if (!caps) {
 165 -               perror("cap_get_proc");
 166 +       __u64 caps;
 167 +
 168 +       /* The test checks for finer cap as CAP_NET_ADMIN,
 169 +        * CAP_PERFMON, and CAP_BPF instead of CAP_SYS_ADMIN.
 170 +        * Thus, disable CAP_SYS_ADMIN at the beginning.
 171 +        */
 172 +       if (cap_disable_effective(1ULL << CAP_SYS_ADMIN, &caps)) {
 173 +               perror("cap_disable_effective(CAP_SYS_ADMIN)");
 174                 return false;
 175         }
 176 -       cap = (struct libcap *)caps;
 177 -       bpf_priv = cap->data[1].effective & (1 << (39/* CAP_BPF */ - 32));
 178 -       perfmon_priv = cap->data[1].effective & (1 << (38/* CAP_PERFMON */ - 32));
 179 -       if (cap_get_flag(caps, CAP_NET_ADMIN, CAP_EFFECTIVE, &net_priv))
 180 -               perror("cap_get_flag NET");
 181 -       if (cap_free(caps))
 182 -               perror("cap_free");
 183 -       return bpf_priv && perfmon_priv && net_priv == CAP_SET;
 184 +
 185 +       return (caps & ADMIN_CAPS) == ADMIN_CAPS;
 186  }
 187
 188  static void get_unpriv_disabled()