Merge branch 'dmi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging

Pull dmi subsystem updates/fixes from Jean Delvare.

* 'dmi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
  firmware: dmi: handle missing DMI data gracefully
  firmware: dmi_scan: Fix handling of empty DMI strings
  firmware: dmi_scan: Drop dmi_initialized
  firmware: dmi: Optimize dmi_matches

Author: torvalds

drivers/firmware/dmi-sysfs.c

@@ -652,7 +652,7 @@ static int __init dmi_sysfs_init(void)
 	int val;
 
 	if (!dmi_kobj) {
-		pr_err("dmi-sysfs: dmi entry is absent.\n");
+		pr_debug("dmi-sysfs: dmi entry is absent.\n");
 		error = -ENODATA;
 		goto err;
 	}

drivers/firmware/dmi_scan.c

@@ -18,19 +18,14 @@ EXPORT_SYMBOL_GPL(dmi_kobj);
  * of and an antecedent to, SMBIOS, which stands for System
  * Management BIOS.  See further: http://www.dmtf.org/standards
  */
-static const char dmi_empty_string[] = "        ";
+static const char dmi_empty_string[] = "";
 
 static u32 dmi_ver __initdata;
 static u32 dmi_len;
 static u16 dmi_num;
 static u8 smbios_entry_point[32];
 static int smbios_entry_point_size;
 
-/*
- * Catch too early calls to dmi_check_system():
- */
-static int dmi_initialized;
-
 /* DMI system identification string used during boot */
 static char dmi_ids_string[128] __initdata;
 
@@ -44,25 +39,21 @@ static int dmi_memdev_nr;
 static const char * __init dmi_string_nosave(const struct dmi_header *dm, u8 s)
 {
 	const u8 *bp = ((u8 *) dm) + dm->length;
+	const u8 *nsp;
 
 	if (s) {
-		s--;
-		while (s > 0 && *bp) {
+		while (--s > 0 && *bp)
 			bp += strlen(bp) + 1;
-			s--;
-		}
 
-		if (*bp != 0) {
-			size_t len = strlen(bp)+1;
-			size_t cmp_len = len > 8 ? 8 : len;
-
-			if (!memcmp(bp, dmi_empty_string, cmp_len))
-				return dmi_empty_string;
+		/* Strings containing only spaces are considered empty */
+		nsp = bp;
+		while (*nsp == ' ')
+			nsp++;
+		if (*nsp != '\0')
 			return bp;
-		}
 	}
 
-	return "";
+	return dmi_empty_string;
 }
 
 static const char * __init dmi_string(const struct dmi_header *dm, u8 s)
@@ -633,7 +624,7 @@ void __init dmi_scan_machine(void)
 
 			if (!dmi_smbios3_present(buf)) {
 				dmi_available = 1;
-				goto out;
+				return;
 			}
 		}
 		if (efi.smbios == EFI_INVALID_TABLE_ADDR)
@@ -651,7 +642,7 @@ void __init dmi_scan_machine(void)
 
 		if (!dmi_present(buf)) {
 			dmi_available = 1;
-			goto out;
+			return;
 		}
 	} else if (IS_ENABLED(CONFIG_DMI_SCAN_MACHINE_NON_EFI_FALLBACK)) {
 		p = dmi_early_remap(0xF0000, 0x10000);
@@ -668,7 +659,7 @@ void __init dmi_scan_machine(void)
 			if (!dmi_smbios3_present(buf)) {
 				dmi_available = 1;
 				dmi_early_unmap(p, 0x10000);
-				goto out;
+				return;
 			}
 			memcpy(buf, buf + 16, 16);
 		}
@@ -686,16 +677,14 @@ void __init dmi_scan_machine(void)
 			if (!dmi_present(buf)) {
 				dmi_available = 1;
 				dmi_early_unmap(p, 0x10000);
-				goto out;
+				return;
 			}
 			memcpy(buf, buf + 16, 16);
 		}
 		dmi_early_unmap(p, 0x10000);
 	}
  error:
 	pr_info("DMI not present or invalid.\n");
- out:
-	dmi_initialized = 1;
 }
 
 static ssize_t raw_table_read(struct file *file, struct kobject *kobj,
@@ -715,10 +704,8 @@ static int __init dmi_init(void)
 	u8 *dmi_table;
 	int ret = -ENOMEM;
 
-	if (!dmi_available) {
-		ret = -ENODATA;
-		goto err;
-	}
+	if (!dmi_available)
+		return 0;
 
 	/*
 	 * Set up dmi directory at /sys/firmware/dmi. This entry should stay
@@ -784,19 +771,20 @@ static bool dmi_matches(const struct dmi_system_id *dmi)
 {
 	int i;
 
-	WARN(!dmi_initialized, KERN_ERR "dmi check: not initialized yet.\n");
-
 	for (i = 0; i < ARRAY_SIZE(dmi->matches); i++) {
 		int s = dmi->matches[i].slot;
 		if (s == DMI_NONE)
 			break;
 		if (dmi_ident[s]) {
-			if (!dmi->matches[i].exact_match &&
-			    strstr(dmi_ident[s], dmi->matches[i].substr))
-				continue;
-			else if (dmi->matches[i].exact_match &&
-				 !strcmp(dmi_ident[s], dmi->matches[i].substr))
-				continue;
+			if (dmi->matches[i].exact_match) {
+				if (!strcmp(dmi_ident[s],
+					    dmi->matches[i].substr))
+					continue;
+			} else {
+				if (strstr(dmi_ident[s],
+					   dmi->matches[i].substr))
+					continue;
+			}
 		}
 
 		/* No match */
@@ -826,6 +814,8 @@ static bool dmi_is_end_of_table(const struct dmi_system_id *dmi)
  *	Walk the blacklist table running matching functions until someone
  *	returns non zero or we hit the end. Callback function is called for
  *	each successful match. Returns the number of matches.
+ *
+ *	dmi_scan_machine must be called before this function is called.
  */
 int dmi_check_system(const struct dmi_system_id *list)
 {
@@ -854,6 +844,8 @@ EXPORT_SYMBOL(dmi_check_system);
  *
  *	Walk the blacklist table until the first match is found.  Return the
  *	pointer to the matching entry or NULL if there's no match.
+ *
+ *	dmi_scan_machine must be called before this function is called.
  */
 const struct dmi_system_id *dmi_first_match(const struct dmi_system_id *list)
 {