From e8dd273d199f5bbe295a8e3d8b777c5505b6b2e1 Mon Sep 17 00:00:00 2001 From: Salah Triki Date: Thu, 17 Sep 2026 14:00:52 +0100 Subject: iio: proximity: isl29501: Fix return type of isl29501_register_write isl29501_register_write() was returning a u32 instead of an int. Since the function returns negative error codes (such as -ERANGE or return values from i2c_smbus_write_byte_data()), returning an unsigned integer type prevents callers from correctly checking for negative error conditions. Fix this by changing the function return type from u32 to int. This was found through manual code review. Fixes: 1c28799257bc ("iio: light: isl29501: Add support for the ISL29501 ToF sensor.") Signed-off-by: Salah Triki Reviewed-by: Joshua Crofts Cc: stable@vger.kernel.org Signed-off-by: Jonathan Cameron --- lib/error-inject.c | 239 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 239 insertions(+) create mode 100644 lib/error-inject.c (limited to 'lib/error-inject.c') diff --git a/lib/error-inject.c b/lib/error-inject.c new file mode 100644 index 000000000..32f3d1ca9 --- /dev/null +++ b/lib/error-inject.c @@ -0,0 +1,239 @@ +// SPDX-License-Identifier: GPL-2.0 +// error-inject.c: Function-level error injection table +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* 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; + int ei_type = -EINVAL; + + mutex_lock(&ei_mutex); + list_for_each_entry(ent, &error_injection_list, list) { + if (addr >= ent->start_addr && addr < ent->end_addr) { + ei_type = ent->etype; + break; + } + } + mutex_unlock(&ei_mutex); + + return ei_type; +} + +/* + * 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 = (unsigned long)dereference_symbol_descriptor((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_obj(*ent); + 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"; + case EI_ETYPE_TRUE: + return "TRUE"; + 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, "%ps\t%s\n", (void *)ent->start_addr, + error_type_string(ent->etype)); + return 0; +} + +static const struct seq_operations ei_sops = { + .start = ei_seq_start, + .next = ei_seq_next, + .stop = ei_seq_stop, + .show = ei_seq_show, +}; + +DEFINE_SEQ_ATTRIBUTE(ei); + +static int __init ei_debugfs_init(void) +{ + struct dentry *dir, *file; + + dir = debugfs_create_dir("error_injection", NULL); + + file = debugfs_create_file("list", 0444, dir, NULL, &ei_fops); + if (IS_ERR(file)) { + debugfs_remove(dir); + return PTR_ERR(file); + } + + 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); -- cgit v1.3.1