MdePkg/BasePrintLib: Fix incomplete print output
authorWang, Jian J <jian.j.wang@intel.com>
Tue, 2 Jan 2018 08:20:20 +0000 (16:20 +0800)
committerLiming Gao <liming.gao@intel.com>
Tue, 2 Jan 2018 08:31:19 +0000 (16:31 +0800)
This is caused by previous patch which tried to fix string over-read,
which breaks UEFI menu rendering: the following

/------------------------------------------------------------------------------\
|                               Device Manager                                 |
\------------------------------------------------------------------------------/

is rendered as

/\
|                               Device Manager                                 |
\/.0                                                 2.00 GHz

(the spurious digits are SMBIOS data from the home screen)

The problem appears to be that the CHAR16 value of BOXDRAW_HORIZONTAL
equals 0x2500, which means that testing ArgumentString[] != '\0'
(which tests the low byte only) will yield FALSE and terminate the
loop prematurely.

Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Liming Gao <liming.gao@intel.com>
MdePkg/Library/BasePrintLib/PrintLibInternal.c

index fc57255068485222fce76ea5b94b6c80d2556943..6f19b314496b4b190df386697d5e53fc5fda6080 100644 (file)
@@ -1108,7 +1108,9 @@ BasePrintLibSPrintMarker (
       // ArgumentString is either null-terminated, or it contains Precision characters\r
       //\r
       for (Count = 0;\r
-            ArgumentString[Count * BytesPerArgumentCharacter] != '\0' &&\r
+            (ArgumentString[Count * BytesPerArgumentCharacter] != '\0' ||\r
+             (BytesPerArgumentCharacter > 1 &&\r
+              ArgumentString[Count * BytesPerArgumentCharacter + 1]!= '\0')) &&\r
             (Count < Precision || ((Flags & PRECISION) == 0));\r
               Count++) {\r
         ArgumentCharacter = ((ArgumentString[Count * BytesPerArgumentCharacter] & 0xff) | ((ArgumentString[Count * BytesPerArgumentCharacter + 1]) << 8)) & ArgumentMask;\r
@@ -1167,7 +1169,9 @@ BasePrintLibSPrintMarker (
     //\r
     // Copy the string into the output buffer performing the required type conversions\r
     //\r
-    while (Index < Count && (*ArgumentString) != '\0') {\r
+    while (Index < Count &&\r
+           (ArgumentString[0] != '\0' ||\r
+            (BytesPerArgumentCharacter > 1 && ArgumentString[1] != '\0'))) {\r
       ArgumentCharacter = ((*ArgumentString & 0xff) | (((UINT8)*(ArgumentString + 1)) << 8)) & ArgumentMask;\r
 \r
       LengthToReturn += (1 * BytesPerOutputCharacter);\r