drivers/platform/x86/acerhdf.c: check BIOS information whether it begins with string of table

BIOS information is now checked whether it begins with the strings stored
in the BIOS table.  Previous method did a strcmp, what lead to problems if
BIOS information has appended whitespaces.

Signed-off-by: Peter Feuerer <peter@piie.net>
Cc: Borislav Petkov <petkovbb@gmail.com>
Cc: Andreas Mohr <andi@lisas.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 28 insertions, 18 deletions

diff --git a/drivers/platform/x86/acerhdf.c b/drivers/platform/x86/acerhdf.c
index a97fc4a7c600..7b2384d674d0 100644
--- a/drivers/platform/x86/acerhdf.c
+++ b/drivers/platform/x86/acerhdf.c
@@ -52,7 +52,7 @@
  */
 #undef START_IN_KERNEL_MODE
 
-#define DRV_VER "0.5.21"
+#define DRV_VER "0.5.22"
 
 /*
  * According to the Atom N270 datasheet,
@@ -165,12 +165,9 @@ static const struct bios_settings_t bios_tbl[] = {
         /* Gateway */
         {"Gateway", "AOA110", "v0.3103", 0x55, 0x58, {0x21, 0x21, 0x00} },
         {"Gateway", "AOA150", "v0.3103", 0x55, 0x58, {0x20, 0x20, 0x00} },
-        {"Gateway         ", "LT31            ", "v1.3103 ", 0x55, 0x58,
-                {0x10, 0x0f, 0x00} },
-        {"Gateway         ", "LT31            ", "v1.3201 ", 0x55, 0x58,
-                {0x10, 0x0f, 0x00} },
-        {"Gateway         ", "LT31            ", "v1.3302 ", 0x55, 0x58,
-                {0x10, 0x0f, 0x00} },
+        {"Gateway", "LT31", "v1.3103", 0x55, 0x58, {0x10, 0x0f, 0x00} },
+        {"Gateway", "LT31", "v1.3201", 0x55, 0x58, {0x10, 0x0f, 0x00} },
+        {"Gateway", "LT31", "v1.3302", 0x55, 0x58, {0x10, 0x0f, 0x00} },
         /* Packard Bell */
         {"Packard Bell", "DOA150", "v0.3104", 0x55, 0x58, {0x21, 0x21, 0x00} },
         {"Packard Bell", "DOA150", "v0.3105", 0x55, 0x58, {0x20, 0x20, 0x00} },
@@ -495,13 +492,26 @@ static struct platform_driver acerhdf_driver = {
         .remove = acerhdf_remove,
 };
 
+/* checks if str begins with start */
+static int str_starts_with(const char *str, const char *start)
+{
+        unsigned long str_len = 0, start_len = 0;
+
+        str_len = strlen(str);
+        start_len = strlen(start);
+
+        if (str_len >= start_len &&
+                        !strncmp(str, start, start_len))
+                return 1;
+
+        return 0;
+}
 
 /* check hardware */
 static int acerhdf_check_hardware(void)
 {
         char const *vendor, *version, *product;
-        int i;
-        unsigned long prod_len = 0;
+        const struct bios_settings_t *bt = NULL;
 
         /* get BIOS data */
         vendor  = dmi_get_system_info(DMI_SYS_VENDOR);
@@ -523,20 +533,20 @@ static int acerhdf_check_hardware(void)
                 kernelmode = 0;
         }
 
-        prod_len = strlen(product);
-
         if (verbose)
                 pr_info("BIOS info: %s %s, product: %s\n",
                         vendor, version, product);
 
         /* search BIOS version and vendor in BIOS settings table */
-        for (i = 0; bios_tbl[i].version[0]; i++) {
-                if (strlen(bios_tbl[i].product) >= prod_len &&
-                    !strncmp(bios_tbl[i].product, product,
-                           strlen(bios_tbl[i].product)) &&
-                    !strcmp(bios_tbl[i].vendor, vendor) &&
-                    !strcmp(bios_tbl[i].version, version)) {
-                        bios_cfg = &bios_tbl[i];
+        for (bt = bios_tbl; bt->vendor[0]; bt++) {
+                /*
+                 * check if actual hardware BIOS vendor, product and version
+                 * IDs start with the strings of BIOS table entry
+                 */
+                if (str_starts_with(vendor, bt->vendor) &&
+                                str_starts_with(product, bt->product) &&
+                                str_starts_with(version, bt->version)) {
+                        bios_cfg = bt;
                         break;
                 }
         }