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-rw-r--r--lib/Kconfig.debug14
-rw-r--r--lib/Makefile1
-rw-r--r--lib/error-inject.c242
-rw-r--r--lib/test_bpf.c115
4 files changed, 368 insertions, 4 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);
diff --git a/lib/test_bpf.c b/lib/test_bpf.c
index 9e9748089270..e3938e395cba 100644
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -6109,6 +6109,110 @@ static struct bpf_test tests[] = {
{ { ETH_HLEN, 42 } },
.fill_helper = bpf_fill_ld_abs_vlan_push_pop2,
},
+ /* Checking interpreter vs JIT wrt signed extended imms. */
+ {
+ "JNE signed compare, test 1",
+ .u.insns_int = {
+ BPF_ALU32_IMM(BPF_MOV, R1, 0xfefbbc12),
+ BPF_ALU32_IMM(BPF_MOV, R3, 0xffff0000),
+ BPF_MOV64_REG(R2, R1),
+ BPF_ALU64_REG(BPF_AND, R2, R3),
+ BPF_ALU32_IMM(BPF_MOV, R0, 1),
+ BPF_JMP_IMM(BPF_JNE, R2, -17104896, 1),
+ BPF_ALU32_IMM(BPF_MOV, R0, 2),
+ BPF_EXIT_INSN(),
+ },
+ INTERNAL,
+ { },
+ { { 0, 1 } },
+ },
+ {
+ "JNE signed compare, test 2",
+ .u.insns_int = {
+ BPF_ALU32_IMM(BPF_MOV, R1, 0xfefbbc12),
+ BPF_ALU32_IMM(BPF_MOV, R3, 0xffff0000),
+ BPF_MOV64_REG(R2, R1),
+ BPF_ALU64_REG(BPF_AND, R2, R3),
+ BPF_ALU32_IMM(BPF_MOV, R0, 1),
+ BPF_JMP_IMM(BPF_JNE, R2, 0xfefb0000, 1),
+ BPF_ALU32_IMM(BPF_MOV, R0, 2),
+ BPF_EXIT_INSN(),
+ },
+ INTERNAL,
+ { },
+ { { 0, 1 } },
+ },
+ {
+ "JNE signed compare, test 3",
+ .u.insns_int = {
+ BPF_ALU32_IMM(BPF_MOV, R1, 0xfefbbc12),
+ BPF_ALU32_IMM(BPF_MOV, R3, 0xffff0000),
+ BPF_ALU32_IMM(BPF_MOV, R4, 0xfefb0000),
+ BPF_MOV64_REG(R2, R1),
+ BPF_ALU64_REG(BPF_AND, R2, R3),
+ BPF_ALU32_IMM(BPF_MOV, R0, 1),
+ BPF_JMP_REG(BPF_JNE, R2, R4, 1),
+ BPF_ALU32_IMM(BPF_MOV, R0, 2),
+ BPF_EXIT_INSN(),
+ },
+ INTERNAL,
+ { },
+ { { 0, 2 } },
+ },
+ {
+ "JNE signed compare, test 4",
+ .u.insns_int = {
+ BPF_LD_IMM64(R1, -17104896),
+ BPF_ALU32_IMM(BPF_MOV, R0, 1),
+ BPF_JMP_IMM(BPF_JNE, R1, -17104896, 1),
+ BPF_ALU32_IMM(BPF_MOV, R0, 2),
+ BPF_EXIT_INSN(),
+ },
+ INTERNAL,
+ { },
+ { { 0, 2 } },
+ },
+ {
+ "JNE signed compare, test 5",
+ .u.insns_int = {
+ BPF_LD_IMM64(R1, 0xfefb0000),
+ BPF_ALU32_IMM(BPF_MOV, R0, 1),
+ BPF_JMP_IMM(BPF_JNE, R1, 0xfefb0000, 1),
+ BPF_ALU32_IMM(BPF_MOV, R0, 2),
+ BPF_EXIT_INSN(),
+ },
+ INTERNAL,
+ { },
+ { { 0, 1 } },
+ },
+ {
+ "JNE signed compare, test 6",
+ .u.insns_int = {
+ BPF_LD_IMM64(R1, 0x7efb0000),
+ BPF_ALU32_IMM(BPF_MOV, R0, 1),
+ BPF_JMP_IMM(BPF_JNE, R1, 0x7efb0000, 1),
+ BPF_ALU32_IMM(BPF_MOV, R0, 2),
+ BPF_EXIT_INSN(),
+ },
+ INTERNAL,
+ { },
+ { { 0, 2 } },
+ },
+ {
+ "JNE signed compare, test 7",
+ .u.insns = {
+ BPF_STMT(BPF_LD | BPF_IMM, 0xffff0000),
+ BPF_STMT(BPF_MISC | BPF_TAX, 0),
+ BPF_STMT(BPF_LD | BPF_IMM, 0xfefbbc12),
+ BPF_STMT(BPF_ALU | BPF_AND | BPF_X, 0),
+ BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0xfefb0000, 1, 0),
+ BPF_STMT(BPF_RET | BPF_K, 1),
+ BPF_STMT(BPF_RET | BPF_K, 2),
+ },
+ CLASSIC | FLAG_NO_DATA,
+ {},
+ { { 0, 2 } },
+ },
};
static struct net_device dev;
@@ -6250,9 +6354,8 @@ static struct bpf_prog *generate_filter(int which, int *err)
return NULL;
}
}
- /* We don't expect to fail. */
if (*err) {
- pr_cont("FAIL to attach err=%d len=%d\n",
+ pr_cont("FAIL to prog_create err=%d len=%d\n",
*err, fprog.len);
return NULL;
}
@@ -6276,6 +6379,10 @@ static struct bpf_prog *generate_filter(int which, int *err)
* checks.
*/
fp = bpf_prog_select_runtime(fp, err);
+ if (*err) {
+ pr_cont("FAIL to select_runtime err=%d\n", *err);
+ return NULL;
+ }
break;
}
@@ -6461,8 +6568,8 @@ static __init int test_bpf(void)
pass_cnt++;
continue;
}
-
- return err;
+ err_cnt++;
+ continue;
}
pr_cont("jited:%u ", fp->jited);
generated by cgit v1.2.3 (git 2.39.1) at 2025-05-20 20:03:19 +0000