Change in simtrace2[master]: stdio: fix detection of malformated format strings

[Harald Welte]

Harald Welte has submitted this change and it was merged. ( https://gerrit.osmocom.org/10671 )

Change subject: stdio: fix detection of malformated format strings
......................................................................

stdio: fix detection of malformated format strings

the error code returned by vsnprintf was ignored,
resulting in printing the string from a previous print.

Change-Id: I8506b05d56da55d1357a1234917adf341b46e1db
---
M firmware/libcommon/source/stdio.c
1 file changed, 18 insertions(+), 8 deletions(-)

Approvals:
  Jenkins Builder: Verified
  Harald Welte: Looks good to me, approved



diff --git a/firmware/libcommon/source/stdio.c b/firmware/libcommon/source/stdio.c
index 2bfaed7..a8612d1 100644
--- a/firmware/libcommon/source/stdio.c
+++ b/firmware/libcommon/source/stdio.c
@@ -429,12 +429,17 @@
 signed int vfprintf(FILE *pStream, const char *pFormat, va_list ap)
 {
 	char pStr[MAX_STRING_SIZE];
-	char pError[] = "stdio.c: increase MAX_STRING_SIZE\n\r";
 
 	// Write formatted string in buffer
-	if (vsprintf(pStr, pFormat, ap) >= MAX_STRING_SIZE) {
-
-		fputs(pError, stderr);
+	int rc = vsprintf(pStr, pFormat, ap);
+	if (rc < 0) {
+		fputs("format string error in ", stderr);
+		fputs(pFormat, stderr);
+		return rc;
+	}
+	if (rc >= MAX_STRING_SIZE) {
+		fputs("stdio.c: increase MAX_STRING_SIZE\n\r", stderr);
+		return rc;
 	}
 
 	// Display string
@@ -454,12 +459,17 @@
 signed int vfprintf_sync(FILE *pStream, const char *pFormat, va_list ap)
 {
 	char pStr[MAX_STRING_SIZE];
-	char pError[] = "stdio.c: increase MAX_STRING_SIZE\n\r";
 
 	// Write formatted string in buffer
-	if (vsprintf(pStr, pFormat, ap) >= MAX_STRING_SIZE) {
-
-		fputs_sync(pError, stderr);
+	int rc = vsprintf(pStr, pFormat, ap);
+	if (rc < 0) {
+		fputs_sync("format string error in ", stderr);
+		fputs_sync(pFormat, stderr);
+		return rc;
+	}
+	if (rc >= MAX_STRING_SIZE) {
+		fputs_sync("stdio.c: increase MAX_STRING_SIZE\n\r", stderr);
+		return rc;
 	}
 
 	// Display string

-- 
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Gerrit-Project: simtrace2
Gerrit-Branch: master
Gerrit-MessageType: merged
Gerrit-Change-Id: I8506b05d56da55d1357a1234917adf341b46e1db
Gerrit-Change-Number: 10671
Gerrit-PatchSet: 2
Gerrit-Owner: Kévin Redon <kredon at sysmocom.de>
Gerrit-Reviewer: Harald Welte <laforge at gnumonks.org>
Gerrit-Reviewer: Jenkins Builder (1000002)
Gerrit-Reviewer: Kévin Redon <kredon at sysmocom.de>
Gerrit-CC: Neels Hofmeyr <nhofmeyr at sysmocom.de>
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