From 85eb035e6cfd615071256592e1dbe72c1d99c24b Mon Sep 17 00:00:00 2001 From: Hao Sun Date: Wed, 1 Nov 2023 13:33:52 +0100 Subject: selftests/bpf: Add test for immediate spilled to stack Add a test to check if the verifier correctly reason about the sign of an immediate spilled to stack by BPF_ST instruction. Signed-off-by: Hao Sun Link: https://lore.kernel.org/r/20231101-fix-check-stack-write-v3-2-f05c2b1473d5@gmail.com Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/verifier/bpf_st_mem.c | 32 +++++++++++++++++++++++ 1 file changed, 32 insertions(+) (limited to 'tools/testing') diff --git a/tools/testing/selftests/bpf/verifier/bpf_st_mem.c b/tools/testing/selftests/bpf/verifier/bpf_st_mem.c index 3af2501082b2..b616575c3b00 100644 --- a/tools/testing/selftests/bpf/verifier/bpf_st_mem.c +++ b/tools/testing/selftests/bpf/verifier/bpf_st_mem.c @@ -65,3 +65,35 @@ .expected_attach_type = BPF_SK_LOOKUP, .runs = -1, }, +{ + "BPF_ST_MEM stack imm sign", + /* Check if verifier correctly reasons about sign of an + * immediate spilled to stack by BPF_ST instruction. + * + * fp[-8] = -44; + * r0 = fp[-8]; + * if r0 s< 0 goto ret0; + * r0 = -1; + * exit; + * ret0: + * r0 = 0; + * exit; + */ + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, -44), + BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8), + BPF_JMP_IMM(BPF_JSLT, BPF_REG_0, 0, 2), + BPF_MOV64_IMM(BPF_REG_0, -1), + BPF_EXIT_INSN(), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + /* Use prog type that requires return value in range [0, 1] */ + .prog_type = BPF_PROG_TYPE_SK_LOOKUP, + .expected_attach_type = BPF_SK_LOOKUP, + .result = VERBOSE_ACCEPT, + .runs = -1, + .errstr = "0: (7a) *(u64 *)(r10 -8) = -44 ; R10=fp0 fp-8_w=-44\ + 2: (c5) if r0 s< 0x0 goto pc+2\ + R0_w=-44", +}, -- cgit v1.2.3 From cd60f410ddc0cd663045d15936155421b6f708fd Mon Sep 17 00:00:00 2001 From: Manu Bretelle Date: Tue, 31 Oct 2023 15:36:06 -0700 Subject: selftests/bpf: fix test_bpffs Currently this tests tries to umount /sys/kernel/debug (TDIR) but the system it is running on may have mounts below. For example, danobi/vmtest [0] VMs have mount -t tracefs tracefs /sys/kernel/debug/tracing as part of their init. This change instead creates a "random" directory under /tmp and uses this as TDIR. If the directory already exists, ignore the error and keep moving on. Test: Originally: $ vmtest -k $KERNEL_REPO/arch/x86_64/boot/bzImage "./test_progs -vv -a test_bpffs" => bzImage ===> Booting ===> Setting up VM ===> Running command [ 2.138818] bpf_testmod: loading out-of-tree module taints kernel. [ 2.140913] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel bpf_testmod.ko is already unloaded. Loading bpf_testmod.ko... Successfully loaded bpf_testmod.ko. test_test_bpffs:PASS:clone 0 nsec fn:PASS:unshare 0 nsec fn:PASS:mount / 0 nsec fn:FAIL:umount /sys/kernel/debug unexpected error: -1 (errno 16) bpf_testmod.ko is already unloaded. Loading bpf_testmod.ko... Successfully loaded bpf_testmod.ko. test_test_bpffs:PASS:clone 0 nsec test_test_bpffs:PASS:waitpid 0 nsec test_test_bpffs:FAIL:bpffs test failed 255#282 test_bpffs:FAIL Summary: 0/0 PASSED, 0 SKIPPED, 1 FAILED Successfully unloaded bpf_testmod.ko. Command failed with exit code: 1 After this change: $ vmtest -k $(make image_name) 'cd tools/testing/selftests/bpf && ./test_progs -vv -a test_bpffs' => bzImage ===> Booting ===> Setting up VM ===> Running command [ 2.295696] bpf_testmod: loading out-of-tree module taints kernel. [ 2.296468] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel bpf_testmod.ko is already unloaded. Loading bpf_testmod.ko... Successfully loaded bpf_testmod.ko. test_test_bpffs:PASS:clone 0 nsec fn:PASS:unshare 0 nsec fn:PASS:mount / 0 nsec fn:PASS:mount tmpfs 0 nsec fn:PASS:mkdir /tmp/test_bpffs_testdir/fs1 0 nsec fn:PASS:mkdir /tmp/test_bpffs_testdir/fs2 0 nsec fn:PASS:mount bpffs /tmp/test_bpffs_testdir/fs1 0 nsec fn:PASS:mount bpffs /tmp/test_bpffs_testdir/fs2 0 nsec fn:PASS:reading /tmp/test_bpffs_testdir/fs1/maps.debug 0 nsec fn:PASS:reading /tmp/test_bpffs_testdir/fs2/progs.debug 0 nsec fn:PASS:creating /tmp/test_bpffs_testdir/fs1/a 0 nsec fn:PASS:creating /tmp/test_bpffs_testdir/fs1/a/1 0 nsec fn:PASS:creating /tmp/test_bpffs_testdir/fs1/b 0 nsec fn:PASS:create_map(ARRAY) 0 nsec fn:PASS:pin map 0 nsec fn:PASS:stat(/tmp/test_bpffs_testdir/fs1/a) 0 nsec fn:PASS:renameat2(/fs1/a, /fs1/b, RENAME_EXCHANGE) 0 nsec fn:PASS:stat(/tmp/test_bpffs_testdir/fs1/b) 0 nsec fn:PASS:b should have a's inode 0 nsec fn:PASS:access(/tmp/test_bpffs_testdir/fs1/b/1) 0 nsec fn:PASS:stat(/tmp/test_bpffs_testdir/fs1/map) 0 nsec fn:PASS:renameat2(/fs1/c, /fs1/b, RENAME_EXCHANGE) 0 nsec fn:PASS:stat(/tmp/test_bpffs_testdir/fs1/b) 0 nsec fn:PASS:b should have c's inode 0 nsec fn:PASS:access(/tmp/test_bpffs_testdir/fs1/c/1) 0 nsec fn:PASS:renameat2(RENAME_NOREPLACE) 0 nsec fn:PASS:access(/tmp/test_bpffs_testdir/fs1/b) 0 nsec bpf_testmod.ko is already unloaded. Loading bpf_testmod.ko... Successfully loaded bpf_testmod.ko. test_test_bpffs:PASS:clone 0 nsec test_test_bpffs:PASS:waitpid 0 nsec test_test_bpffs:PASS:bpffs test 0 nsec #282 test_bpffs:OK Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED Successfully unloaded bpf_testmod.ko. [0] https://github.com/danobi/vmtest This is a follow-up of https://lore.kernel.org/bpf/20231024201852.1512720-1-chantr4@gmail.com/T/ v1 -> v2: - use a TDIR name that is related to test - use C-style comments Signed-off-by: Manu Bretelle Acked-by: Jiri Olsa Link: https://lore.kernel.org/r/20231031223606.2927976-1-chantr4@gmail.com Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/prog_tests/test_bpffs.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'tools/testing') diff --git a/tools/testing/selftests/bpf/prog_tests/test_bpffs.c b/tools/testing/selftests/bpf/prog_tests/test_bpffs.c index 214d9f4a94a5..ea933fd151c3 100644 --- a/tools/testing/selftests/bpf/prog_tests/test_bpffs.c +++ b/tools/testing/selftests/bpf/prog_tests/test_bpffs.c @@ -8,7 +8,8 @@ #include #include -#define TDIR "/sys/kernel/debug" +/* TDIR must be in a location we can create a directory in. */ +#define TDIR "/tmp/test_bpffs_testdir" static int read_iter(char *file) { @@ -43,8 +44,11 @@ static int fn(void) if (!ASSERT_OK(err, "mount /")) goto out; - err = umount(TDIR); - if (!ASSERT_OK(err, "umount " TDIR)) + err = mkdir(TDIR, 0777); + /* If the directory already exists we can carry on. It may be left over + * from a previous run. + */ + if ((err && errno != EEXIST) && !ASSERT_OK(err, "mkdir " TDIR)) goto out; err = mount("none", TDIR, "tmpfs", 0, NULL); @@ -138,6 +142,7 @@ out: rmdir(TDIR "/fs1"); rmdir(TDIR "/fs2"); umount(TDIR); + rmdir(TDIR); exit(err); } -- cgit v1.2.3 From 15fb6f2b6c4c3c129adc2412ae12ec15e60a6adb Mon Sep 17 00:00:00 2001 From: Dave Marchevsky Date: Tue, 31 Oct 2023 14:56:25 -0700 Subject: bpf: Add __bpf_hook_{start,end} macros Not all uses of __diag_ignore_all(...) in BPF-related code in order to suppress warnings are wrapping kfunc definitions. Some "hook point" definitions - small functions meant to be used as attach points for fentry and similar BPF progs - need to suppress -Wmissing-declarations. We could use __bpf_kfunc_{start,end}_defs added in the previous patch in such cases, but this might be confusing to someone unfamiliar with BPF internals. Instead, this patch adds __bpf_hook_{start,end} macros, currently having the same effect as __bpf_kfunc_{start,end}_defs, then uses them to suppress warnings for two hook points in the kernel itself and some bpf_testmod hook points as well. Signed-off-by: Dave Marchevsky Cc: Yafang Shao Acked-by: Jiri Olsa Acked-by: Yafang Shao Link: https://lore.kernel.org/r/20231031215625.2343848-2-davemarchevsky@fb.com Signed-off-by: Alexei Starovoitov --- include/linux/btf.h | 2 ++ kernel/cgroup/rstat.c | 9 +++------ net/socket.c | 8 ++------ tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c | 6 ++---- 4 files changed, 9 insertions(+), 16 deletions(-) (limited to 'tools/testing') diff --git a/include/linux/btf.h b/include/linux/btf.h index dc5ce962f600..59d404e22814 100644 --- a/include/linux/btf.h +++ b/include/linux/btf.h @@ -92,6 +92,8 @@ "Global kfuncs as their definitions will be in BTF") #define __bpf_kfunc_end_defs() __diag_pop() +#define __bpf_hook_start() __bpf_kfunc_start_defs() +#define __bpf_hook_end() __bpf_kfunc_end_defs() /* * Return the name of the passed struct, if exists, or halt the build if for diff --git a/kernel/cgroup/rstat.c b/kernel/cgroup/rstat.c index d80d7a608141..c0adb7254b45 100644 --- a/kernel/cgroup/rstat.c +++ b/kernel/cgroup/rstat.c @@ -156,19 +156,16 @@ static struct cgroup *cgroup_rstat_cpu_pop_updated(struct cgroup *pos, * optimize away the callsite. Therefore, __weak is needed to ensure that the * call is still emitted, by telling the compiler that we don't know what the * function might eventually be. - * - * __diag_* below are needed to dismiss the missing prototype warning. */ -__diag_push(); -__diag_ignore_all("-Wmissing-prototypes", - "kfuncs which will be used in BPF programs"); + +__bpf_hook_start(); __weak noinline void bpf_rstat_flush(struct cgroup *cgrp, struct cgroup *parent, int cpu) { } -__diag_pop(); +__bpf_hook_end(); /* see cgroup_rstat_flush() */ static void cgroup_rstat_flush_locked(struct cgroup *cgrp) diff --git a/net/socket.c b/net/socket.c index 0d1c4e78fc7f..3379c64217a4 100644 --- a/net/socket.c +++ b/net/socket.c @@ -1685,20 +1685,16 @@ struct file *__sys_socket_file(int family, int type, int protocol) * Therefore, __weak is needed to ensure that the call is still * emitted, by telling the compiler that we don't know what the * function might eventually be. - * - * __diag_* below are needed to dismiss the missing prototype warning. */ -__diag_push(); -__diag_ignore_all("-Wmissing-prototypes", - "A fmod_ret entry point for BPF programs"); +__bpf_hook_start(); __weak noinline int update_socket_protocol(int family, int type, int protocol) { return protocol; } -__diag_pop(); +__bpf_hook_end(); int __sys_socket(int family, int type, int protocol) { diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c index a5e246f7b202..91907b321f91 100644 --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c @@ -39,9 +39,7 @@ struct bpf_testmod_struct_arg_4 { int b; }; -__diag_push(); -__diag_ignore_all("-Wmissing-prototypes", - "Global functions as their definitions will be in bpf_testmod.ko BTF"); +__bpf_hook_start(); noinline int bpf_testmod_test_struct_arg_1(struct bpf_testmod_struct_arg_2 a, int b, int c) { @@ -335,7 +333,7 @@ noinline int bpf_fentry_shadow_test(int a) } EXPORT_SYMBOL_GPL(bpf_fentry_shadow_test); -__diag_pop(); +__bpf_hook_end(); static struct bin_attribute bin_attr_bpf_testmod_file __ro_after_init = { .attr = { .name = "bpf_testmod", .mode = 0666, }, -- cgit v1.2.3 From 9af3775962afa8b5cd0cc30c1e454405a650c1f3 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Sat, 28 Oct 2023 18:15:09 -0700 Subject: selftests/bpf: fix test_maps' use of bpf_map_create_opts Use LIBBPF_OPTS() macro to properly initialize bpf_map_create_opts in test_maps' tests. Signed-off-by: Andrii Nakryiko Acked-by: Yonghong Song Link: https://lore.kernel.org/r/20231029011509.2479232-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov --- .../selftests/bpf/map_tests/map_percpu_stats.c | 20 +++++--------------- 1 file changed, 5 insertions(+), 15 deletions(-) (limited to 'tools/testing') diff --git a/tools/testing/selftests/bpf/map_tests/map_percpu_stats.c b/tools/testing/selftests/bpf/map_tests/map_percpu_stats.c index 1a9eeefda9a8..8bf497a9843e 100644 --- a/tools/testing/selftests/bpf/map_tests/map_percpu_stats.c +++ b/tools/testing/selftests/bpf/map_tests/map_percpu_stats.c @@ -326,20 +326,14 @@ static int map_create(__u32 type, const char *name, struct bpf_map_create_opts * static int create_hash(void) { - struct bpf_map_create_opts map_opts = { - .sz = sizeof(map_opts), - .map_flags = BPF_F_NO_PREALLOC, - }; + LIBBPF_OPTS(bpf_map_create_opts, map_opts, .map_flags = BPF_F_NO_PREALLOC); return map_create(BPF_MAP_TYPE_HASH, "hash", &map_opts); } static int create_percpu_hash(void) { - struct bpf_map_create_opts map_opts = { - .sz = sizeof(map_opts), - .map_flags = BPF_F_NO_PREALLOC, - }; + LIBBPF_OPTS(bpf_map_create_opts, map_opts, .map_flags = BPF_F_NO_PREALLOC); return map_create(BPF_MAP_TYPE_PERCPU_HASH, "percpu_hash", &map_opts); } @@ -356,21 +350,17 @@ static int create_percpu_hash_prealloc(void) static int create_lru_hash(__u32 type, __u32 map_flags) { - struct bpf_map_create_opts map_opts = { - .sz = sizeof(map_opts), - .map_flags = map_flags, - }; + LIBBPF_OPTS(bpf_map_create_opts, map_opts, .map_flags = map_flags); return map_create(type, "lru_hash", &map_opts); } static int create_hash_of_maps(void) { - struct bpf_map_create_opts map_opts = { - .sz = sizeof(map_opts), + LIBBPF_OPTS(bpf_map_create_opts, map_opts, .map_flags = BPF_F_NO_PREALLOC, .inner_map_fd = create_small_hash(), - }; + ); int ret; ret = map_create_opts(BPF_MAP_TYPE_HASH_OF_MAPS, "hash_of_maps", -- cgit v1.2.3 From 3091b667498b0a212e760e1033e5f9b8c33a948f Mon Sep 17 00:00:00 2001 From: Chuyi Zhou Date: Tue, 31 Oct 2023 13:04:36 +0800 Subject: bpf: Relax allowlist for css_task iter The newly added open-coded css_task iter would try to hold the global css_set_lock in bpf_iter_css_task_new, so the bpf side has to be careful in where it allows to use this iter. The mainly concern is dead locking on css_set_lock. check_css_task_iter_allowlist() in verifier enforced css_task can only be used in bpf_lsm hooks and sleepable bpf_iter. This patch relax the allowlist for css_task iter. Any lsm and any iter (even non-sleepable) and any sleepable are safe since they would not hold the css_set_lock before entering BPF progs context. This patch also fixes the misused BPF_TRACE_ITER in check_css_task_iter_allowlist which compared bpf_prog_type with bpf_attach_type. Fixes: 9c66dc94b62ae ("bpf: Introduce css_task open-coded iterator kfuncs") Signed-off-by: Chuyi Zhou Acked-by: Yonghong Song Link: https://lore.kernel.org/r/20231031050438.93297-2-zhouchuyi@bytedance.com Signed-off-by: Alexei Starovoitov --- kernel/bpf/verifier.c | 16 ++++++++++++---- tools/testing/selftests/bpf/progs/iters_task_failure.c | 4 ++-- 2 files changed, 14 insertions(+), 6 deletions(-) (limited to 'tools/testing') diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 014b4d1ef408..def99b1a2b17 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -11402,6 +11402,12 @@ static int process_kf_arg_ptr_to_rbtree_node(struct bpf_verifier_env *env, &meta->arg_rbtree_root.field); } +/* + * css_task iter allowlist is needed to avoid dead locking on css_set_lock. + * LSM hooks and iters (both sleepable and non-sleepable) are safe. + * Any sleepable progs are also safe since bpf_check_attach_target() enforce + * them can only be attached to some specific hook points. + */ static bool check_css_task_iter_allowlist(struct bpf_verifier_env *env) { enum bpf_prog_type prog_type = resolve_prog_type(env->prog); @@ -11409,10 +11415,12 @@ static bool check_css_task_iter_allowlist(struct bpf_verifier_env *env) switch (prog_type) { case BPF_PROG_TYPE_LSM: return true; - case BPF_TRACE_ITER: - return env->prog->aux->sleepable; + case BPF_PROG_TYPE_TRACING: + if (env->prog->expected_attach_type == BPF_TRACE_ITER) + return true; + fallthrough; default: - return false; + return env->prog->aux->sleepable; } } @@ -11671,7 +11679,7 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ case KF_ARG_PTR_TO_ITER: if (meta->func_id == special_kfunc_list[KF_bpf_iter_css_task_new]) { if (!check_css_task_iter_allowlist(env)) { - verbose(env, "css_task_iter is only allowed in bpf_lsm and bpf iter-s\n"); + verbose(env, "css_task_iter is only allowed in bpf_lsm, bpf_iter and sleepable progs\n"); return -EINVAL; } } diff --git a/tools/testing/selftests/bpf/progs/iters_task_failure.c b/tools/testing/selftests/bpf/progs/iters_task_failure.c index c3bf96a67dba..6b1588d70652 100644 --- a/tools/testing/selftests/bpf/progs/iters_task_failure.c +++ b/tools/testing/selftests/bpf/progs/iters_task_failure.c @@ -84,8 +84,8 @@ int BPF_PROG(iter_css_lock_and_unlock) return 0; } -SEC("?fentry.s/" SYS_PREFIX "sys_getpgid") -__failure __msg("css_task_iter is only allowed in bpf_lsm and bpf iter-s") +SEC("?fentry/" SYS_PREFIX "sys_getpgid") +__failure __msg("css_task_iter is only allowed in bpf_lsm, bpf_iter and sleepable progs") int BPF_PROG(iter_css_task_for_each) { u64 cg_id = bpf_get_current_cgroup_id(); -- cgit v1.2.3 From f49843afde6771ef6ed5d021eacafacfc98a58bf Mon Sep 17 00:00:00 2001 From: Chuyi Zhou Date: Tue, 31 Oct 2023 13:04:37 +0800 Subject: selftests/bpf: Add tests for css_task iter combining with cgroup iter This patch adds a test which demonstrates how css_task iter can be combined with cgroup iter and it won't cause deadlock, though cgroup iter is not sleepable. Signed-off-by: Chuyi Zhou Acked-by: Yonghong Song Link: https://lore.kernel.org/r/20231031050438.93297-3-zhouchuyi@bytedance.com Signed-off-by: Alexei Starovoitov --- .../testing/selftests/bpf/prog_tests/cgroup_iter.c | 33 ++++++++++++++++ tools/testing/selftests/bpf/progs/iters_css_task.c | 44 ++++++++++++++++++++++ 2 files changed, 77 insertions(+) (limited to 'tools/testing') diff --git a/tools/testing/selftests/bpf/prog_tests/cgroup_iter.c b/tools/testing/selftests/bpf/prog_tests/cgroup_iter.c index e02feb5fae97..574d9a0cdc8e 100644 --- a/tools/testing/selftests/bpf/prog_tests/cgroup_iter.c +++ b/tools/testing/selftests/bpf/prog_tests/cgroup_iter.c @@ -4,6 +4,7 @@ #include #include #include +#include "iters_css_task.skel.h" #include "cgroup_iter.skel.h" #include "cgroup_helpers.h" @@ -263,6 +264,35 @@ close_cgrp: close(cgrp_fd); } +static void test_walk_self_only_css_task(void) +{ + struct iters_css_task *skel; + int err; + + skel = iters_css_task__open(); + if (!ASSERT_OK_PTR(skel, "skel_open")) + return; + + bpf_program__set_autoload(skel->progs.cgroup_id_printer, true); + + err = iters_css_task__load(skel); + if (!ASSERT_OK(err, "skel_load")) + goto cleanup; + + err = join_cgroup(cg_path[CHILD2]); + if (!ASSERT_OK(err, "join_cgroup")) + goto cleanup; + + skel->bss->target_pid = getpid(); + snprintf(expected_output, sizeof(expected_output), + PROLOGUE "%8llu\n" EPILOGUE, cg_id[CHILD2]); + read_from_cgroup_iter(skel->progs.cgroup_id_printer, cg_fd[CHILD2], + BPF_CGROUP_ITER_SELF_ONLY, "test_walk_self_only_css_task"); + ASSERT_EQ(skel->bss->css_task_cnt, 1, "css_task_cnt"); +cleanup: + iters_css_task__destroy(skel); +} + void test_cgroup_iter(void) { struct cgroup_iter *skel = NULL; @@ -293,6 +323,9 @@ void test_cgroup_iter(void) test_walk_self_only(skel); if (test__start_subtest("cgroup_iter__dead_self_only")) test_walk_dead_self_only(skel); + if (test__start_subtest("cgroup_iter__self_only_css_task")) + test_walk_self_only_css_task(); + out: cgroup_iter__destroy(skel); cleanup_cgroups(); diff --git a/tools/testing/selftests/bpf/progs/iters_css_task.c b/tools/testing/selftests/bpf/progs/iters_css_task.c index 5089ce384a1c..384ff806990f 100644 --- a/tools/testing/selftests/bpf/progs/iters_css_task.c +++ b/tools/testing/selftests/bpf/progs/iters_css_task.c @@ -10,6 +10,7 @@ char _license[] SEC("license") = "GPL"; +struct cgroup *bpf_cgroup_acquire(struct cgroup *p) __ksym; struct cgroup *bpf_cgroup_from_id(u64 cgid) __ksym; void bpf_cgroup_release(struct cgroup *p) __ksym; @@ -45,3 +46,46 @@ int BPF_PROG(iter_css_task_for_each, struct vm_area_struct *vma, return -EPERM; } + +static inline u64 cgroup_id(struct cgroup *cgrp) +{ + return cgrp->kn->id; +} + +SEC("?iter/cgroup") +int cgroup_id_printer(struct bpf_iter__cgroup *ctx) +{ + struct seq_file *seq = ctx->meta->seq; + struct cgroup *cgrp, *acquired; + struct cgroup_subsys_state *css; + struct task_struct *task; + u64 cgrp_id; + + cgrp = ctx->cgroup; + + /* epilogue */ + if (cgrp == NULL) { + BPF_SEQ_PRINTF(seq, "epilogue\n"); + return 0; + } + + /* prologue */ + if (ctx->meta->seq_num == 0) + BPF_SEQ_PRINTF(seq, "prologue\n"); + + cgrp_id = cgroup_id(cgrp); + + BPF_SEQ_PRINTF(seq, "%8llu\n", cgrp_id); + + acquired = bpf_cgroup_from_id(cgrp_id); + if (!acquired) + return 0; + css = &acquired->self; + css_task_cnt = 0; + bpf_for_each(css_task, task, css, CSS_TASK_ITER_PROCS) { + if (task->pid == target_pid) + css_task_cnt++; + } + bpf_cgroup_release(acquired); + return 0; +} -- cgit v1.2.3 From d8234d47c4aa494d789b85562fa90e837b4575f9 Mon Sep 17 00:00:00 2001 From: Chuyi Zhou Date: Tue, 31 Oct 2023 13:04:38 +0800 Subject: selftests/bpf: Add test for using css_task iter in sleepable progs This Patch add a test to prove css_task iter can be used in normal sleepable progs. Signed-off-by: Chuyi Zhou Acked-by: Yonghong Song Link: https://lore.kernel.org/r/20231031050438.93297-4-zhouchuyi@bytedance.com Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/prog_tests/iters.c | 1 + tools/testing/selftests/bpf/progs/iters_css_task.c | 19 +++++++++++++++++++ 2 files changed, 20 insertions(+) (limited to 'tools/testing') diff --git a/tools/testing/selftests/bpf/prog_tests/iters.c b/tools/testing/selftests/bpf/prog_tests/iters.c index c2425791c923..bf84d4a1d9ae 100644 --- a/tools/testing/selftests/bpf/prog_tests/iters.c +++ b/tools/testing/selftests/bpf/prog_tests/iters.c @@ -294,6 +294,7 @@ void test_iters(void) RUN_TESTS(iters_state_safety); RUN_TESTS(iters_looping); RUN_TESTS(iters); + RUN_TESTS(iters_css_task); if (env.has_testmod) RUN_TESTS(iters_testmod_seq); diff --git a/tools/testing/selftests/bpf/progs/iters_css_task.c b/tools/testing/selftests/bpf/progs/iters_css_task.c index 384ff806990f..e180aa1b1d52 100644 --- a/tools/testing/selftests/bpf/progs/iters_css_task.c +++ b/tools/testing/selftests/bpf/progs/iters_css_task.c @@ -89,3 +89,22 @@ int cgroup_id_printer(struct bpf_iter__cgroup *ctx) bpf_cgroup_release(acquired); return 0; } + +SEC("?fentry.s/" SYS_PREFIX "sys_getpgid") +int BPF_PROG(iter_css_task_for_each_sleep) +{ + u64 cgrp_id = bpf_get_current_cgroup_id(); + struct cgroup *cgrp = bpf_cgroup_from_id(cgrp_id); + struct cgroup_subsys_state *css; + struct task_struct *task; + + if (cgrp == NULL) + return 0; + css = &cgrp->self; + + bpf_for_each(css_task, task, css, CSS_TASK_ITER_PROCS) { + + } + bpf_cgroup_release(cgrp); + return 0; +} -- cgit v1.2.3 From 3c41971550f58f2e006c58aa71e8c23ad312110f Mon Sep 17 00:00:00 2001 From: Shung-Hsi Yu Date: Thu, 2 Nov 2023 13:39:05 +0800 Subject: selftests/bpf: precision tracking test for BPF_NEG and BPF_END As seen from previous commit that fix backtracking for BPF_ALU | BPF_TO_BE | BPF_END, both BPF_NEG and BPF_END require special handling. Add tests written with inline assembly to check that the verifier does not incorrecly use the src_reg field of BPF_NEG and BPF_END (including bswap added in v4). Suggested-by: Eduard Zingerman Signed-off-by: Shung-Hsi Yu Link: https://lore.kernel.org/r/20231102053913.12004-4-shung-hsi.yu@suse.com Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/prog_tests/verifier.c | 2 + .../selftests/bpf/progs/verifier_precision.c | 93 ++++++++++++++++++++++ 2 files changed, 95 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/verifier_precision.c (limited to 'tools/testing') diff --git a/tools/testing/selftests/bpf/prog_tests/verifier.c b/tools/testing/selftests/bpf/prog_tests/verifier.c index e3e68c97b40c..e5c61aa6604a 100644 --- a/tools/testing/selftests/bpf/prog_tests/verifier.c +++ b/tools/testing/selftests/bpf/prog_tests/verifier.c @@ -46,6 +46,7 @@ #include "verifier_movsx.skel.h" #include "verifier_netfilter_ctx.skel.h" #include "verifier_netfilter_retcode.skel.h" +#include "verifier_precision.skel.h" #include "verifier_prevent_map_lookup.skel.h" #include "verifier_raw_stack.skel.h" #include "verifier_raw_tp_writable.skel.h" @@ -153,6 +154,7 @@ void test_verifier_meta_access(void) { RUN(verifier_meta_access); } void test_verifier_movsx(void) { RUN(verifier_movsx); } void test_verifier_netfilter_ctx(void) { RUN(verifier_netfilter_ctx); } void test_verifier_netfilter_retcode(void) { RUN(verifier_netfilter_retcode); } +void test_verifier_precision(void) { RUN(verifier_precision); } void test_verifier_prevent_map_lookup(void) { RUN(verifier_prevent_map_lookup); } void test_verifier_raw_stack(void) { RUN(verifier_raw_stack); } void test_verifier_raw_tp_writable(void) { RUN(verifier_raw_tp_writable); } diff --git a/tools/testing/selftests/bpf/progs/verifier_precision.c b/tools/testing/selftests/bpf/progs/verifier_precision.c new file mode 100644 index 000000000000..193c0f8272d0 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/verifier_precision.c @@ -0,0 +1,93 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) 2023 SUSE LLC */ +#include +#include +#include "bpf_misc.h" + +SEC("?raw_tp") +__success __log_level(2) +__msg("mark_precise: frame0: regs=r2 stack= before 3: (bf) r1 = r10") +__msg("mark_precise: frame0: regs=r2 stack= before 2: (55) if r2 != 0xfffffff8 goto pc+2") +__msg("mark_precise: frame0: regs=r2 stack= before 1: (87) r2 = -r2") +__msg("mark_precise: frame0: regs=r2 stack= before 0: (b7) r2 = 8") +__naked int bpf_neg(void) +{ + asm volatile ( + "r2 = 8;" + "r2 = -r2;" + "if r2 != -8 goto 1f;" + "r1 = r10;" + "r1 += r2;" + "1:" + "r0 = 0;" + "exit;" + ::: __clobber_all); +} + +SEC("?raw_tp") +__success __log_level(2) +__msg("mark_precise: frame0: regs=r2 stack= before 3: (bf) r1 = r10") +__msg("mark_precise: frame0: regs=r2 stack= before 2: (55) if r2 != 0x0 goto pc+2") +__msg("mark_precise: frame0: regs=r2 stack= before 1: (d4) r2 = le16 r2") +__msg("mark_precise: frame0: regs=r2 stack= before 0: (b7) r2 = 0") +__naked int bpf_end_to_le(void) +{ + asm volatile ( + "r2 = 0;" + "r2 = le16 r2;" + "if r2 != 0 goto 1f;" + "r1 = r10;" + "r1 += r2;" + "1:" + "r0 = 0;" + "exit;" + ::: __clobber_all); +} + + +SEC("?raw_tp") +__success __log_level(2) +__msg("mark_precise: frame0: regs=r2 stack= before 3: (bf) r1 = r10") +__msg("mark_precise: frame0: regs=r2 stack= before 2: (55) if r2 != 0x0 goto pc+2") +__msg("mark_precise: frame0: regs=r2 stack= before 1: (dc) r2 = be16 r2") +__msg("mark_precise: frame0: regs=r2 stack= before 0: (b7) r2 = 0") +__naked int bpf_end_to_be(void) +{ + asm volatile ( + "r2 = 0;" + "r2 = be16 r2;" + "if r2 != 0 goto 1f;" + "r1 = r10;" + "r1 += r2;" + "1:" + "r0 = 0;" + "exit;" + ::: __clobber_all); +} + +#if (defined(__TARGET_ARCH_arm64) || defined(__TARGET_ARCH_x86) || \ + (defined(__TARGET_ARCH_riscv) && __riscv_xlen == 64) || \ + defined(__TARGET_ARCH_arm) || defined(__TARGET_ARCH_s390)) && \ + __clang_major__ >= 18 + +SEC("?raw_tp") +__success __log_level(2) +__msg("mark_precise: frame0: regs=r2 stack= before 3: (bf) r1 = r10") +__msg("mark_precise: frame0: regs=r2 stack= before 2: (55) if r2 != 0x0 goto pc+2") +__msg("mark_precise: frame0: regs=r2 stack= before 1: (d7) r2 = bswap16 r2") +__msg("mark_precise: frame0: regs=r2 stack= before 0: (b7) r2 = 0") +__naked int bpf_end_bswap(void) +{ + asm volatile ( + "r2 = 0;" + "r2 = bswap16 r2;" + "if r2 != 0 goto 1f;" + "r1 = r10;" + "r1 += r2;" + "1:" + "r0 = 0;" + "exit;" + ::: __clobber_all); +} + +#endif /* v4 instruction */ -- cgit v1.2.3 From d84b139f53e8fa8048f16814c6b2a53d7bc15c3d Mon Sep 17 00:00:00 2001 From: Björn Töpel Date: Thu, 2 Nov 2023 11:35:37 +0100 Subject: selftests/bpf: Fix broken build where char is unsigned MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit There are architectures where char is not signed. If so, the following error is triggered: | xdp_hw_metadata.c:435:42: error: result of comparison of constant -1 \ | with expression of type 'char' is always true \ | [-Werror,-Wtautological-constant-out-of-range-compare] | 435 | while ((opt = getopt(argc, argv, "mh")) != -1) { | | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~ | 1 error generated. Correct by changing the char to int. Fixes: bb6a88885fde ("selftests/bpf: Add options and frags to xdp_hw_metadata") Signed-off-by: Björn Töpel Acked-by: Larysa Zaremba Tested-by: Anders Roxell Link: https://lore.kernel.org/r/20231102103537.247336-1-bjorn@kernel.org Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/xdp_hw_metadata.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'tools/testing') diff --git a/tools/testing/selftests/bpf/xdp_hw_metadata.c b/tools/testing/selftests/bpf/xdp_hw_metadata.c index 17c0f92ff160..c3ba40d0b9de 100644 --- a/tools/testing/selftests/bpf/xdp_hw_metadata.c +++ b/tools/testing/selftests/bpf/xdp_hw_metadata.c @@ -430,7 +430,7 @@ static void print_usage(void) static void read_args(int argc, char *argv[]) { - char opt; + int opt; while ((opt = getopt(argc, argv, "mh")) != -1) { switch (opt) { -- cgit v1.2.3 From 3c5864ba9cf912ff9809f315d28f296f21563cce Mon Sep 17 00:00:00 2001 From: Chuyi Zhou Date: Tue, 7 Nov 2023 21:22:04 +0800 Subject: selftests/bpf: get trusted cgrp from bpf_iter__cgroup directly Commit f49843afde (selftests/bpf: Add tests for css_task iter combining with cgroup iter) added a test which demonstrates how css_task iter can be combined with cgroup iter. That test used bpf_cgroup_from_id() to convert bpf_iter__cgroup->cgroup to a trusted ptr which is pointless now, since with the previous fix, we can get a trusted cgroup directly from bpf_iter__cgroup. Signed-off-by: Chuyi Zhou Acked-by: Yonghong Song Link: https://lore.kernel.org/r/20231107132204.912120-3-zhouchuyi@bytedance.com Signed-off-by: Martin KaFai Lau --- tools/testing/selftests/bpf/progs/iters_css_task.c | 16 ++++------------ 1 file changed, 4 insertions(+), 12 deletions(-) (limited to 'tools/testing') diff --git a/tools/testing/selftests/bpf/progs/iters_css_task.c b/tools/testing/selftests/bpf/progs/iters_css_task.c index e180aa1b1d52..9ac758649cb8 100644 --- a/tools/testing/selftests/bpf/progs/iters_css_task.c +++ b/tools/testing/selftests/bpf/progs/iters_css_task.c @@ -56,12 +56,9 @@ SEC("?iter/cgroup") int cgroup_id_printer(struct bpf_iter__cgroup *ctx) { struct seq_file *seq = ctx->meta->seq; - struct cgroup *cgrp, *acquired; + struct cgroup *cgrp = ctx->cgroup; struct cgroup_subsys_state *css; struct task_struct *task; - u64 cgrp_id; - - cgrp = ctx->cgroup; /* epilogue */ if (cgrp == NULL) { @@ -73,20 +70,15 @@ int cgroup_id_printer(struct bpf_iter__cgroup *ctx) if (ctx->meta->seq_num == 0) BPF_SEQ_PRINTF(seq, "prologue\n"); - cgrp_id = cgroup_id(cgrp); - - BPF_SEQ_PRINTF(seq, "%8llu\n", cgrp_id); + BPF_SEQ_PRINTF(seq, "%8llu\n", cgroup_id(cgrp)); - acquired = bpf_cgroup_from_id(cgrp_id); - if (!acquired) - return 0; - css = &acquired->self; + css = &cgrp->self; css_task_cnt = 0; bpf_for_each(css_task, task, css, CSS_TASK_ITER_PROCS) { if (task->pid == target_pid) css_task_cnt++; } - bpf_cgroup_release(acquired); + return 0; } -- cgit v1.2.3