3 files changed, 62 insertions, 21 deletions

diff --git a/drivers/acpi/blacklist.c b/drivers/acpi/blacklist.c
index f6baa77deefb..0c4ca4d318b3 100644
--- a/drivers/acpi/blacklist.c
+++ b/drivers/acpi/blacklist.c
@@ -78,9 +78,10 @@ static struct acpi_blacklist_item acpi_blacklist[] __initdata = {
 
 static int __init blacklist_by_year(void)
 {
-        int year = dmi_get_year(DMI_BIOS_DATE);
+        int year;
+
         /* Doesn't exist? Likely an old system */
-        if (year == -1) {
+        if (!dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL)) {
                 printk(KERN_ERR PREFIX "no DMI BIOS year, "
                         "acpi=force is required to enable ACPI\n" );
                 return 1;
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index be4c39f8ab81..147b9be3b4d2 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -2679,7 +2679,7 @@ static bool ahci_asus_m2a_vm_32bit_only(struct pci_dev *pdev)
          * different versions.
          */
         date = dmi_get_system_info(DMI_BIOS_DATE);
-        year = dmi_get_year(DMI_BIOS_DATE);
+        dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL);
         if (date && strlen(date) >= 10 && date[2] == '/' && date[5] == '/' &&
             (year > 2007 ||
              (year == 2007 && strncmp(date, cutoff_mmdd, 5) >= 0)))
diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c
index 531e621677ce..938100f14b16 100644
--- a/drivers/firmware/dmi_scan.c
+++ b/drivers/firmware/dmi_scan.c
@@ -568,36 +568,76 @@ const struct dmi_device * dmi_find_device(int type, const char *name,
 EXPORT_SYMBOL(dmi_find_device);
 
 /**
- *      dmi_get_year - Return year of a DMI date
- *      @field: data index (like dmi_get_system_info)
+ *      dmi_get_date - parse a DMI date
+ *      @field: data index (see enum dmi_field)
+ *      @yearp: optional out parameter for the year
+ *      @monthp: optional out parameter for the month
+ *      @dayp: optional out parameter for the day
  *
- *      Returns -1 when the field doesn't exist. 0 when it is broken.
+ *      The date field is assumed to be in the form resembling
+ *      [mm[/dd]]/yy[yy] and the result is stored in the out
+ *      parameters any or all of which can be omitted.
+ *
+ *      If the field doesn't exist, all out parameters are set to zero
+ *      and false is returned.  Otherwise, true is returned with any
+ *      invalid part of date set to zero.
+ *
+ *      On return, year, month and day are guaranteed to be in the
+ *      range of [0,9999], [0,12] and [0,31] respectively.
  */
-int dmi_get_year(int field)
+bool dmi_get_date(int field, int *yearp, int *monthp, int *dayp)
 {
-        int year;
-        const char *s = dmi_get_system_info(field);
+        int year = 0, month = 0, day = 0;
+        bool exists;
+        const char *s, *y;
         char *e;
 
-        if (!s)
-                return -1;
-        if (*s == '\0')
-                return 0;
-        s = strrchr(s, '/');
-        if (!s)
-                return 0;
+        s = dmi_get_system_info(field);
+        exists = s;
+        if (!exists)
+                goto out;
 
-        s += 1;
-        year = simple_strtoul(s, &e, 10);
-        if (s != e && year < 100) {     /* 2-digit year */
+        /*
+         * Determine year first.  We assume the date string resembles
+         * mm/dd/yy[yy] but the original code extracted only the year
+         * from the end.  Keep the behavior in the spirit of no
+         * surprises.
+         */
+        y = strrchr(s, '/');
+        if (!y)
+                goto out;
+
+        y++;
+        year = simple_strtoul(y, &e, 10);
+        if (y != e && year < 100) {     /* 2-digit year */
                 year += 1900;
                 if (year < 1996)        /* no dates < spec 1.0 */
                         year += 100;
         }
+        if (year > 9999)                /* year should fit in %04d */
+                year = 0;
+
+        /* parse the mm and dd */
+        month = simple_strtoul(s, &e, 10);
+        if (s == e || *e != '/' || !month || month > 12) {
+                month = 0;
+                goto out;
+        }
 
-        return year;
+        s = e + 1;
+        day = simple_strtoul(s, &e, 10);
+        if (s == y || s == e || *e != '/' || day > 31)
+                day = 0;
+out:
+        if (yearp)
+                *yearp = year;
+        if (monthp)
+                *monthp = month;
+        if (dayp)
+                *dayp = day;
+        return exists;
 }
-EXPORT_SYMBOL(dmi_get_year);
+EXPORT_SYMBOL(dmi_get_date);
 
 /**
  *      dmi_walk - Walk the DMI table and get called back for every record