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hc

2024-02-20 ea08eeccae9297f7aabd2ef7f0c2517ac4549acc

 kernel/drivers/firmware/efi/efi-pstore.c
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@@ -1,3 +1,5 @@
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+// SPDX-License-Identifier: GPL-2.0+
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+
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 #include <linux/efi.h>
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 #include <linux/module.h>
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 #include <linux/pstore.h>
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@@ -5,6 +7,8 @@
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 #include <linux/ucs2_string.h>
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8
 
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 #define DUMP_NAME_LEN 66
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+
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+#define EFIVARS_DATA_SIZE_MAX 1024
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 static bool efivars_pstore_disable =
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 	IS_ENABLED(CONFIG_EFI_VARS_PSTORE_DEFAULT_DISABLE);
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@@ -15,6 +19,9 @@
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 	(EFI_VARIABLE_NON_VOLATILE | \
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 	 EFI_VARIABLE_BOOTSERVICE_ACCESS | \
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 	 EFI_VARIABLE_RUNTIME_ACCESS)
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+
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+static LIST_HEAD(efi_pstore_list);
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+static DECLARE_WORK(efivar_work, NULL);
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 static int efi_pstore_open(struct pstore_info *psi)
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 {
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@@ -124,7 +131,7 @@
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 	if (entry->deleting) {
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 		list_del(&entry->list);
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 		efivar_entry_iter_end();
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-		efivar_unregister(entry);
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+		kfree(entry);
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 		if (efivar_entry_iter_begin())
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 			return -EINTR;
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 	} else if (turn_off_scanning)
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@@ -159,7 +166,7 @@
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  *
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  * @record: pstore record to pass to callback
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  *
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- * You MUST call efivar_enter_iter_begin() before this function, and
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+ * You MUST call efivar_entry_iter_begin() before this function, and
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  * efivar_entry_iter_end() afterwards.
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  *
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  */
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@@ -167,7 +174,7 @@
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 {
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 	struct efivar_entry **pos = (struct efivar_entry **)&record->psi->data;
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 	struct efivar_entry *entry, *n;
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-	struct list_head *head = &efivar_sysfs_list;
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+	struct list_head *head = &efi_pstore_list;
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 	int size = 0;
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 	int ret;
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@@ -261,8 +268,9 @@
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 	ret = efivar_entry_set_safe(efi_name, vendor, PSTORE_EFI_ATTRIBUTES,
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 			      preemptible(), record->size, record->psi->buf);
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-	if (record->reason == KMSG_DUMP_OOPS)
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-		efivar_run_worker();
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+	if (record->reason == KMSG_DUMP_OOPS && try_module_get(THIS_MODULE))
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+		if (!schedule_work(&efivar_work))
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+			module_put(THIS_MODULE);
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 	return ret;
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 };
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@@ -312,12 +320,12 @@
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 	if (efivar_entry_iter_begin())
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 		return -EINTR;
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-	found = __efivar_entry_iter(efi_pstore_erase_func, &efivar_sysfs_list,
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+	found = __efivar_entry_iter(efi_pstore_erase_func, &efi_pstore_list,
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 				    efi_name, &entry);
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 	efivar_entry_iter_end();
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 	if (found && !entry->scanning)
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-		efivar_unregister(entry);
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+		kfree(entry);
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 	return found ? 0 : -ENOENT;
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 }
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@@ -352,16 +360,76 @@
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 	.erase		= efi_pstore_erase,
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 };
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-static __init int efivars_pstore_init(void)
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+static int efi_pstore_callback(efi_char16_t *name, efi_guid_t vendor,
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+			       unsigned long name_size, void *data)
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 {
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-	if (!efi_enabled(EFI_RUNTIME_SERVICES))
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+	struct efivar_entry *entry;
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+	int ret;
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+
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+	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
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+	if (!entry)
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+		return -ENOMEM;
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+
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+	memcpy(entry->var.VariableName, name, name_size);
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+	entry->var.VendorGuid = vendor;
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+
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+	ret = efivar_entry_add(entry, &efi_pstore_list);
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+	if (ret)
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+		kfree(entry);
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+
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+	return ret;
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+}
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+
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+static int efi_pstore_update_entry(efi_char16_t *name, efi_guid_t vendor,
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+				   unsigned long name_size, void *data)
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+{
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+	struct efivar_entry *entry = data;
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+
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+	if (efivar_entry_find(name, vendor, &efi_pstore_list, false))
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 		return 0;
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-	if (!efivars_kobject())
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+	memcpy(entry->var.VariableName, name, name_size);
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+	memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t));
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+
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+	return 1;
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+}
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+
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+static void efi_pstore_update_entries(struct work_struct *work)
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+{
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+	struct efivar_entry *entry;
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+	int err;
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+
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+	/* Add new sysfs entries */
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+	while (1) {
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+		entry = kzalloc(sizeof(*entry), GFP_KERNEL);
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+		if (!entry)
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+			return;
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+
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+		err = efivar_init(efi_pstore_update_entry, entry,
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+				  false, &efi_pstore_list);
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+		if (!err)
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+			break;
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+
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+		efivar_entry_add(entry, &efi_pstore_list);
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+	}
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+
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+	kfree(entry);
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+	module_put(THIS_MODULE);
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+}
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+
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+static __init int efivars_pstore_init(void)
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+{
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+	int ret;
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+
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+	if (!efivars_kobject() || !efivar_supports_writes())
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 		return 0;
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 	if (efivars_pstore_disable)
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 		return 0;
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+
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+	ret = efivar_init(efi_pstore_callback, NULL, true, &efi_pstore_list);
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+	if (ret)
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+		return ret;
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 	efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL);
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 	if (!efi_pstore_info.buf)
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@@ -375,6 +443,8 @@
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 		efi_pstore_info.bufsize = 0;
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 	}
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+	INIT_WORK(&efivar_work, efi_pstore_update_entries);
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+
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 	return 0;
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 }
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