diff options
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/Kconfig | 6 | ||||
| -rw-r--r-- | kernel/trace/bpf_trace.c | 214 | ||||
| -rw-r--r-- | kernel/trace/ftrace.c | 3 |
3 files changed, 218 insertions, 5 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 1052126bdca2..e9e95c790b8e 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -51,6 +51,12 @@ config HAVE_DYNAMIC_FTRACE_WITH_ARGS This allows for use of regs_get_kernel_argument() and kernel_stack_pointer(). +config HAVE_DYNAMIC_FTRACE_NO_PATCHABLE + bool + help + If the architecture generates __patchable_function_entries sections + but does not want them included in the ftrace locations. + config HAVE_FTRACE_MCOUNT_RECORD bool help diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 68e5cdd24cef..49fb9ec8366d 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -20,6 +20,8 @@ #include <linux/fprobe.h> #include <linux/bsearch.h> #include <linux/sort.h> +#include <linux/key.h> +#include <linux/verification.h> #include <net/bpf_sk_storage.h> @@ -1026,11 +1028,30 @@ static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { .arg1_type = ARG_PTR_TO_CTX, }; +#ifdef CONFIG_X86_KERNEL_IBT +static unsigned long get_entry_ip(unsigned long fentry_ip) +{ + u32 instr; + + /* Being extra safe in here in case entry ip is on the page-edge. */ + if (get_kernel_nofault(instr, (u32 *) fentry_ip - 1)) + return fentry_ip; + if (is_endbr(instr)) + fentry_ip -= ENDBR_INSN_SIZE; + return fentry_ip; +} +#else +#define get_entry_ip(fentry_ip) fentry_ip +#endif + BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs) { struct kprobe *kp = kprobe_running(); - return kp ? (uintptr_t)kp->addr : 0; + if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY)) + return 0; + + return get_entry_ip((uintptr_t)kp->addr); } static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { @@ -1181,6 +1202,184 @@ static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = { .arg1_type = ARG_PTR_TO_CTX, }; +#ifdef CONFIG_KEYS +__diag_push(); +__diag_ignore_all("-Wmissing-prototypes", + "kfuncs which will be used in BPF programs"); + +/** + * bpf_lookup_user_key - lookup a key by its serial + * @serial: key handle serial number + * @flags: lookup-specific flags + * + * Search a key with a given *serial* and the provided *flags*. + * If found, increment the reference count of the key by one, and + * return it in the bpf_key structure. + * + * The bpf_key structure must be passed to bpf_key_put() when done + * with it, so that the key reference count is decremented and the + * bpf_key structure is freed. + * + * Permission checks are deferred to the time the key is used by + * one of the available key-specific kfuncs. + * + * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested + * special keyring (e.g. session keyring), if it doesn't yet exist. + * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting + * for the key construction, and to retrieve uninstantiated keys (keys + * without data attached to them). + * + * Return: a bpf_key pointer with a valid key pointer if the key is found, a + * NULL pointer otherwise. + */ +struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags) +{ + key_ref_t key_ref; + struct bpf_key *bkey; + + if (flags & ~KEY_LOOKUP_ALL) + return NULL; + + /* + * Permission check is deferred until the key is used, as the + * intent of the caller is unknown here. + */ + key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK); + if (IS_ERR(key_ref)) + return NULL; + + bkey = kmalloc(sizeof(*bkey), GFP_KERNEL); + if (!bkey) { + key_put(key_ref_to_ptr(key_ref)); + return NULL; + } + + bkey->key = key_ref_to_ptr(key_ref); + bkey->has_ref = true; + + return bkey; +} + +/** + * bpf_lookup_system_key - lookup a key by a system-defined ID + * @id: key ID + * + * Obtain a bpf_key structure with a key pointer set to the passed key ID. + * The key pointer is marked as invalid, to prevent bpf_key_put() from + * attempting to decrement the key reference count on that pointer. The key + * pointer set in such way is currently understood only by + * verify_pkcs7_signature(). + * + * Set *id* to one of the values defined in include/linux/verification.h: + * 0 for the primary keyring (immutable keyring of system keys); + * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring + * (where keys can be added only if they are vouched for by existing keys + * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform + * keyring (primarily used by the integrity subsystem to verify a kexec'ed + * kerned image and, possibly, the initramfs signature). + * + * Return: a bpf_key pointer with an invalid key pointer set from the + * pre-determined ID on success, a NULL pointer otherwise + */ +struct bpf_key *bpf_lookup_system_key(u64 id) +{ + struct bpf_key *bkey; + + if (system_keyring_id_check(id) < 0) + return NULL; + + bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC); + if (!bkey) + return NULL; + + bkey->key = (struct key *)(unsigned long)id; + bkey->has_ref = false; + + return bkey; +} + +/** + * bpf_key_put - decrement key reference count if key is valid and free bpf_key + * @bkey: bpf_key structure + * + * Decrement the reference count of the key inside *bkey*, if the pointer + * is valid, and free *bkey*. + */ +void bpf_key_put(struct bpf_key *bkey) +{ + if (bkey->has_ref) + key_put(bkey->key); + + kfree(bkey); +} + +#ifdef CONFIG_SYSTEM_DATA_VERIFICATION +/** + * bpf_verify_pkcs7_signature - verify a PKCS#7 signature + * @data_ptr: data to verify + * @sig_ptr: signature of the data + * @trusted_keyring: keyring with keys trusted for signature verification + * + * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr* + * with keys in a keyring referenced by *trusted_keyring*. + * + * Return: 0 on success, a negative value on error. + */ +int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr, + struct bpf_dynptr_kern *sig_ptr, + struct bpf_key *trusted_keyring) +{ + int ret; + + if (trusted_keyring->has_ref) { + /* + * Do the permission check deferred in bpf_lookup_user_key(). + * See bpf_lookup_user_key() for more details. + * + * A call to key_task_permission() here would be redundant, as + * it is already done by keyring_search() called by + * find_asymmetric_key(). + */ + ret = key_validate(trusted_keyring->key); + if (ret < 0) + return ret; + } + + return verify_pkcs7_signature(data_ptr->data, + bpf_dynptr_get_size(data_ptr), + sig_ptr->data, + bpf_dynptr_get_size(sig_ptr), + trusted_keyring->key, + VERIFYING_UNSPECIFIED_SIGNATURE, NULL, + NULL); +} +#endif /* CONFIG_SYSTEM_DATA_VERIFICATION */ + +__diag_pop(); + +BTF_SET8_START(key_sig_kfunc_set) +BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE) +BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL) +BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE) +#ifdef CONFIG_SYSTEM_DATA_VERIFICATION +BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE) +#endif +BTF_SET8_END(key_sig_kfunc_set) + +static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = { + .owner = THIS_MODULE, + .set = &key_sig_kfunc_set, +}; + +static int __init bpf_key_sig_kfuncs_init(void) +{ + return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, + &bpf_key_sig_kfunc_set); +} + +late_initcall(bpf_key_sig_kfuncs_init); +#endif /* CONFIG_KEYS */ + static const struct bpf_func_proto * bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) { @@ -1507,6 +1706,9 @@ BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx, if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE)) return -EINVAL; + if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK))) + return -ENOENT; + if (unlikely(!br_stack)) return -ENOENT; @@ -2042,9 +2244,15 @@ static __always_inline void __bpf_trace_run(struct bpf_prog *prog, u64 *args) { cant_sleep(); + if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) { + bpf_prog_inc_misses_counter(prog); + goto out; + } rcu_read_lock(); (void) bpf_prog_run(prog, args); rcu_read_unlock(); +out: + this_cpu_dec(*(prog->active)); } #define UNPACK(...) __VA_ARGS__ @@ -2414,13 +2622,13 @@ kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, } static void -kprobe_multi_link_handler(struct fprobe *fp, unsigned long entry_ip, +kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip, struct pt_regs *regs) { struct bpf_kprobe_multi_link *link; link = container_of(fp, struct bpf_kprobe_multi_link, fp); - kprobe_multi_link_prog_run(link, entry_ip, regs); + kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs); } static int symbols_cmp_r(const void *a, const void *b, const void *priv) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 83362a155791..02e18c436439 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -8285,8 +8285,7 @@ static int kallsyms_callback(void *data, const char *name, if (args->addrs[idx]) return 0; - addr = ftrace_location(addr); - if (!addr) + if (!ftrace_location(addr)) return 0; args->addrs[idx] = addr; |