Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2018-01-17

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Add initial BPF map offloading for nfp driver. Currently only
   programs were supported so far w/o being able to access maps.
   Offloaded programs are right now only allowed to perform map
   lookups, and control path is responsible for populating the
   maps. BPF core infrastructure along with nfp implementation is
   provided, from Jakub.

2) Various follow-ups to Josef's BPF error injections. More
   specifically that includes: properly check whether the error
   injectable event is on function entry or not, remove the percpu
   bpf_kprobe_override and rather compare instruction pointer
   with original one, separate error-injection from kprobes since
   it's not limited to it, add injectable error types in order to
   specify what is the expected type of failure, and last but not
   least also support the kernel's fault injection framework, all
   from Masami.

3) Various misc improvements and cleanups to the libbpf Makefile.
   That is, fix permissions when installing BPF header files, remove
   unused variables and functions, and also install the libbpf.h
   header, from Jesper.

4) When offloading to nfp JIT and the BPF insn is unsupported in the
   JIT, then reject right at verification time. Also fix libbpf with
   regards to ELF section name matching by properly treating the
   program type as prefix. Both from Quentin.

5) Add -DPACKAGE to bpftool when including bfd.h for the disassembler.
   This is needed, for example, when building libfd from source as
   bpftool doesn't supply a config.h for bfd.h. Fix from Jiong.

6) xdp_convert_ctx_access() is simplified since it doesn't need to
   set target size during verification, from Jesper.

7) Let bpftool properly recognize BPF_PROG_TYPE_CGROUP_DEVICE
   program types, from Roman.

8) Various functions in BPF cpumap were not declared static, from Wei.

9) Fix a double semicolon in BPF samples, from Luis.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 257 insertions, 0 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 9d5b78aad4c5..890d4766cef3 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1500,6 +1500,10 @@ config FAULT_INJECTION
           Provide fault-injection framework.
           For more details, see Documentation/fault-injection/.
 
+config FUNCTION_ERROR_INJECTION
+        def_bool y
+        depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
+
 config FAILSLAB
         bool "Fault-injection capability for kmalloc"
         depends on FAULT_INJECTION
@@ -1547,6 +1551,16 @@ config FAIL_FUTEX
         help
           Provide fault-injection capability for futexes.
 
+config FAIL_FUNCTION
+        bool "Fault-injection capability for functions"
+        depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
+        help
+          Provide function-based fault-injection capability.
+          This will allow you to override a specific function with a return
+          with given return value. As a result, function caller will see
+          an error value and have to handle it. This is useful to test the
+          error handling in various subsystems.
+
 config FAULT_INJECTION_DEBUG_FS
         bool "Debugfs entries for fault-injection capabilities"
         depends on FAULT_INJECTION && SYSFS && DEBUG_FS
diff --git a/lib/Makefile b/lib/Makefile
index a6c8529dd9b2..75ec13778cd8 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -149,6 +149,7 @@ obj-$(CONFIG_NETDEV_NOTIFIER_ERROR_INJECT) += netdev-notifier-error-inject.o
 obj-$(CONFIG_MEMORY_NOTIFIER_ERROR_INJECT) += memory-notifier-error-inject.o
 obj-$(CONFIG_OF_RECONFIG_NOTIFIER_ERROR_INJECT) += \
         of-reconfig-notifier-error-inject.o
+obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
 
 lib-$(CONFIG_GENERIC_BUG) += bug.o
 
diff --git a/lib/error-inject.c b/lib/error-inject.c
new file mode 100644
index 000000000000..c0d4600f4896
--- /dev/null
+++ b/lib/error-inject.c
@@ -0,0 +1,242 @@
+// SPDX-License-Identifier: GPL-2.0
+// error-inject.c: Function-level error injection table
+#include <linux/error-injection.h>
+#include <linux/debugfs.h>
+#include <linux/kallsyms.h>
+#include <linux/kprobes.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+
+/* Whitelist of symbols that can be overridden for error injection. */
+static LIST_HEAD(error_injection_list);
+static DEFINE_MUTEX(ei_mutex);
+struct ei_entry {
+        struct list_head list;
+        unsigned long start_addr;
+        unsigned long end_addr;
+        int etype;
+        void *priv;
+};
+
+bool within_error_injection_list(unsigned long addr)
+{
+        struct ei_entry *ent;
+        bool ret = false;
+
+        mutex_lock(&ei_mutex);
+        list_for_each_entry(ent, &error_injection_list, list) {
+                if (addr >= ent->start_addr && addr < ent->end_addr) {
+                        ret = true;
+                        break;
+                }
+        }
+        mutex_unlock(&ei_mutex);
+        return ret;
+}
+
+int get_injectable_error_type(unsigned long addr)
+{
+        struct ei_entry *ent;
+
+        list_for_each_entry(ent, &error_injection_list, list) {
+                if (addr >= ent->start_addr && addr < ent->end_addr)
+                        return ent->etype;
+        }
+        return EI_ETYPE_NONE;
+}
+
+/*
+ * Lookup and populate the error_injection_list.
+ *
+ * For safety reasons we only allow certain functions to be overridden with
+ * bpf_error_injection, so we need to populate the list of the symbols that have
+ * been marked as safe for overriding.
+ */
+static void populate_error_injection_list(struct error_injection_entry *start,
+                                          struct error_injection_entry *end,
+                                          void *priv)
+{
+        struct error_injection_entry *iter;
+        struct ei_entry *ent;
+        unsigned long entry, offset = 0, size = 0;
+
+        mutex_lock(&ei_mutex);
+        for (iter = start; iter < end; iter++) {
+                entry = arch_deref_entry_point((void *)iter->addr);
+
+                if (!kernel_text_address(entry) ||
+                    !kallsyms_lookup_size_offset(entry, &size, &offset)) {
+                        pr_err("Failed to find error inject entry at %p\n",
+                                (void *)entry);
+                        continue;
+                }
+
+                ent = kmalloc(sizeof(*ent), GFP_KERNEL);
+                if (!ent)
+                        break;
+                ent->start_addr = entry;
+                ent->end_addr = entry + size;
+                ent->etype = iter->etype;
+                ent->priv = priv;
+                INIT_LIST_HEAD(&ent->list);
+                list_add_tail(&ent->list, &error_injection_list);
+        }
+        mutex_unlock(&ei_mutex);
+}
+
+/* Markers of the _error_inject_whitelist section */
+extern struct error_injection_entry __start_error_injection_whitelist[];
+extern struct error_injection_entry __stop_error_injection_whitelist[];
+
+static void __init populate_kernel_ei_list(void)
+{
+        populate_error_injection_list(__start_error_injection_whitelist,
+                                      __stop_error_injection_whitelist,
+                                      NULL);
+}
+
+#ifdef CONFIG_MODULES
+static void module_load_ei_list(struct module *mod)
+{
+        if (!mod->num_ei_funcs)
+                return;
+
+        populate_error_injection_list(mod->ei_funcs,
+                                      mod->ei_funcs + mod->num_ei_funcs, mod);
+}
+
+static void module_unload_ei_list(struct module *mod)
+{
+        struct ei_entry *ent, *n;
+
+        if (!mod->num_ei_funcs)
+                return;
+
+        mutex_lock(&ei_mutex);
+        list_for_each_entry_safe(ent, n, &error_injection_list, list) {
+                if (ent->priv == mod) {
+                        list_del_init(&ent->list);
+                        kfree(ent);
+                }
+        }
+        mutex_unlock(&ei_mutex);
+}
+
+/* Module notifier call back, checking error injection table on the module */
+static int ei_module_callback(struct notifier_block *nb,
+                              unsigned long val, void *data)
+{
+        struct module *mod = data;
+
+        if (val == MODULE_STATE_COMING)
+                module_load_ei_list(mod);
+        else if (val == MODULE_STATE_GOING)
+                module_unload_ei_list(mod);
+
+        return NOTIFY_DONE;
+}
+
+static struct notifier_block ei_module_nb = {
+        .notifier_call = ei_module_callback,
+        .priority = 0
+};
+
+static __init int module_ei_init(void)
+{
+        return register_module_notifier(&ei_module_nb);
+}
+#else /* !CONFIG_MODULES */
+#define module_ei_init()        (0)
+#endif
+
+/*
+ * error_injection/whitelist -- shows which functions can be overridden for
+ * error injection.
+ */
+static void *ei_seq_start(struct seq_file *m, loff_t *pos)
+{
+        mutex_lock(&ei_mutex);
+        return seq_list_start(&error_injection_list, *pos);
+}
+
+static void ei_seq_stop(struct seq_file *m, void *v)
+{
+        mutex_unlock(&ei_mutex);
+}
+
+static void *ei_seq_next(struct seq_file *m, void *v, loff_t *pos)
+{
+        return seq_list_next(v, &error_injection_list, pos);
+}
+
+static const char *error_type_string(int etype)
+{
+        switch (etype) {
+        case EI_ETYPE_NULL:
+                return "NULL";
+        case EI_ETYPE_ERRNO:
+                return "ERRNO";
+        case EI_ETYPE_ERRNO_NULL:
+                return "ERRNO_NULL";
+        default:
+                return "(unknown)";
+        }
+}
+
+static int ei_seq_show(struct seq_file *m, void *v)
+{
+        struct ei_entry *ent = list_entry(v, struct ei_entry, list);
+
+        seq_printf(m, "%pf\t%s\n", (void *)ent->start_addr,
+                   error_type_string(ent->etype));
+        return 0;
+}
+
+static const struct seq_operations ei_seq_ops = {
+        .start = ei_seq_start,
+        .next  = ei_seq_next,
+        .stop  = ei_seq_stop,
+        .show  = ei_seq_show,
+};
+
+static int ei_open(struct inode *inode, struct file *filp)
+{
+        return seq_open(filp, &ei_seq_ops);
+}
+
+static const struct file_operations debugfs_ei_ops = {
+        .open           = ei_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = seq_release,
+};
+
+static int __init ei_debugfs_init(void)
+{
+        struct dentry *dir, *file;
+
+        dir = debugfs_create_dir("error_injection", NULL);
+        if (!dir)
+                return -ENOMEM;
+
+        file = debugfs_create_file("list", 0444, dir, NULL, &debugfs_ei_ops);
+        if (!file) {
+                debugfs_remove(dir);
+                return -ENOMEM;
+        }
+
+        return 0;
+}
+
+static int __init init_error_injection(void)
+{
+        populate_kernel_ei_list();
+
+        if (!module_ei_init())
+                ei_debugfs_init();
+
+        return 0;
+}
+late_initcall(init_error_injection);