* Fwd: [PATCH] fgets function warnings fix
[not found] <CA+2y1146jZMaJUCwsoKJjZSNx3NUOe69CiNoDBnX+BdHdbZGdw@mail.gmail.com>
@ 2015-02-26 13:31 ` Stephen Smalley
0 siblings, 0 replies; only message in thread
From: Stephen Smalley @ 2015-02-26 13:31 UTC (permalink / raw)
To: SELinux
[-- Attachment #1: Type: text/plain, Size: 6351 bytes --]
-------- Forwarded Message --------
Subject: [PATCH] fgets function warnings fix
Date: Thu, 26 Feb 2015 11:06:58 +0200
From: Emre Can Kucukoglu <eckucukoglu@gmail.com>
To: Stephen Smalley <sds@tycho.nsa.gov>
2015-02-25 20:25 GMT+02:00 Stephen Smalley <sds@tycho.nsa.gov
<mailto:sds@tycho.nsa.gov>>:
On 02/25/2015 10:42 AM, Emre Can Kucukoglu wrote:
> Hello,
>
> I want to use SELinux for my experimental vanilla kernel
distribution in
> Pandaboard ES. To achieve that I have configured my kernel for SELinux
> support. Then, I have recently cloned selinux userspace repository to
> cross-compile it for arm architecture. I use arm-linux-gnueabi
toolchain
> in Ubuntu 14.04 workstation.
>
> $ export ARCH=arm
> $ export CROSS_COMPILE=arm-linux-gnueabi-
>
> As mentioned in readme instruction,
>
> $ make DESTDIR=~/obj install install-pywrap
>
> command is used, however due to -Werror flags in various Makefile's,
> error is thrown:
>
> dispol.c: In function ‘main’:
> dispol.c:452:8: error: ignoring return value of ‘fgets’,
declared with
> attribute warn_unused_result [-Werror=unused-result]
>Â Â fgets(ans, sizeof(ans), stdin);
>Â Â Â Â Â ^
> dispol.c:479:9: error: ignoring return value of ‘fgets’,
declared with
> attribute warn_unused_result [-Werror=unused-result]
>Â Â Â fgets(ans, sizeof(ans), stdin);
>Â Â Â Â Â ^
> dispol.c:490:9: error: ignoring return value of ‘fgets’,
declared with
> attribute warn_unused_result [-Werror=unused-result]
>Â Â Â fgets(ans, sizeof(ans), stdin);
>Â Â Â Â Â ^
> dispol.c:517:9: error: ignoring return value of ‘fgets’,
declared with
> attribute warn_unused_result [-Werror=unused-result]
>Â Â Â fgets(OutfileName, sizeof(OutfileName), stdin);
>Â Â Â Â Â ^
> cc1: all warnings being treated as errors
> make[2]: *** [dispol.o] Error 1
>
> I did this modification to get over this error which is caused by
> -Werror flag:
>
> char *fgetsret; /* error is given, because return value is not
captured */
> fgetsret = fgets(...);
> if (!fgetsret) { /* if fgetsret is not used, another error comes from
> warning */
> // some exit message
> exit(1);
> }
>
> Did I miss something about SELinux cross-compilation for an arm
> architecture, since constantly I'm taking errors.
Hmm...that's interesting. Builds just fine on Fedora 20. I do
however
get the same error building on Ubuntu 14.04 (which is not something we
typically test on; most SELinux developers work on Fedora).
Willing to accept patches to fix it, but it is merely a test/debugging
program that you can even exclude from your build if you like.
checkpolicy/test/dismod.c and
checkpolicy/test/dispol.c both have same warnings.
Signed-off-by: Emre Can Kucukoglu <eckucukoglu@gmail.com
<mailto:eckucukoglu@gmail.com>>
---
 checkpolicy/test/dismod.c | 20 +++++++++++++++++---
 checkpolicy/test/dispol.c | 24 ++++++++++++++++++++----
 2 files changed, 37 insertions(+), 7 deletions(-)
diff --git a/checkpolicy/test/dismod.c b/checkpolicy/test/dismod.c
index db9ae55..c55f726 100644
--- a/checkpolicy/test/dismod.c
+++ b/checkpolicy/test/dismod.c
@@ -755,7 +755,12 @@ static void link_module(policydb_t * base, FILE *
out_fp)
 return;
 }
 printf("\nModule filename: ");
-fgets(module_name, sizeof(module_name), stdin);
+if (fgets(module_name, sizeof(module_name), stdin) == NULL) {
+fprintf(stderr, "fgets failed at line %d: %s\n", __LINE__,
+strerror(errno));
+exit(1);
+}
+
 module_name[strlen(module_name) - 1] = '\0';/* remove LF */
 if (module_name[0] == '\0') {
 return;
@@ -884,7 +889,12 @@ int main(int argc, char **argv)
 menu();
 for (;;) {
 printf("\nCommand (\'m\' for menu):  ");
-fgets(ans, sizeof(ans), stdin);
+if (fgets(ans, sizeof(ans), stdin) == NULL) {
+fprintf(stderr, "fgets failed at line %d: %s\n", __LINE__,
+strerror(errno));
+continue;
+}
+
 switch (ans[0]) {
 case '1':
@@ -951,7 +961,11 @@ int main(int argc, char **argv)
 case 'f':
 printf
   ("\nFilename for output (<CR> for screen output): ");
-fgets(OutfileName, sizeof(OutfileName), stdin);
+if (fgets(OutfileName, sizeof(OutfileName), stdin) == NULL) {
+fprintf(stderr, "fgets failed at line %d: %s\n", __LINE__,
+strerror(errno));
+break;
+}
 OutfileName[strlen(OutfileName) - 1] = '\0';/* fix_string (remove LF) */
 if (strlen(OutfileName) == 0)
 out_fp = stdout;
diff --git a/checkpolicy/test/dispol.c b/checkpolicy/test/dispol.c
index 9d66358..0333bcc 100644
--- a/checkpolicy/test/dispol.c
+++ b/checkpolicy/test/dispol.c
@@ -449,7 +449,11 @@ int main(int argc, char **argv)
 menu();
 for (;;) {
 printf("\nCommand (\'m\' for menu):  ");
-fgets(ans, sizeof(ans), stdin);
+if (fgets(ans, sizeof(ans), stdin) == NULL) {
+fprintf(stderr, "fgets failed at line %d: %s\n", __LINE__,
+strerror(errno));
+continue;
+}
 switch (ans[0]) {
 case '1':
@@ -476,7 +480,11 @@ int main(int argc, char **argv)
 break;
 case '7':
 printf("name? ");
-fgets(ans, sizeof(ans), stdin);
+if (fgets(ans, sizeof(ans), stdin) == NULL) {
+fprintf(stderr, "fgets failed at line %d: %s\n", __LINE__,
+strerror(errno));
+break;
+}
 ans[strlen(ans) - 1] = 0;
 name = malloc((strlen(ans) + 1) * sizeof(char));
@@ -487,7 +495,11 @@ int main(int argc, char **argv)
 strcpy(name, ans);
 printf("state? ");
-fgets(ans, sizeof(ans), stdin);
+if (fgets(ans, sizeof(ans), stdin) == NULL) {
+fprintf(stderr, "fgets failed at line %d: %s\n", __LINE__,
+strerror(errno));
+break;
+}
 ans[strlen(ans) - 1] = 0;
 if (atoi(ans))
@@ -514,7 +526,11 @@ int main(int argc, char **argv)
 case 'f':
 printf
   ("\nFilename for output (<CR> for screen output): ");
-fgets(OutfileName, sizeof(OutfileName), stdin);
+if (fgets(OutfileName, sizeof(OutfileName), stdin) == NULL) {
+fprintf(stderr, "fgets failed at line %d: %s\n", __LINE__,
+strerror(errno));
+break;
+}
 OutfileName[strlen(OutfileName) - 1] = '\0';/* fix_string (remove LF) */
 if (strlen(OutfileName) == 0)
 out_fp = stdout;
--
1.9.1
--
Emre Can Kucukoglu
[-- Attachment #2: fgets-warnings.patch --]
[-- Type: text/x-patch, Size: 3559 bytes --]
>From dc27dab37d82823095971789fef105eea77aa38a Mon Sep 17 00:00:00 2001
From: Emre Can Kucukoglu <eckucukoglu@gmail.com>
Date: Thu, 26 Feb 2015 10:22:48 +0200
Subject: [PATCH] fgets function warnings fix
---
checkpolicy/test/dismod.c | 20 +++++++++++++++++---
checkpolicy/test/dispol.c | 24 ++++++++++++++++++++----
2 files changed, 37 insertions(+), 7 deletions(-)
diff --git a/checkpolicy/test/dismod.c b/checkpolicy/test/dismod.c
index db9ae55..c55f726 100644
--- a/checkpolicy/test/dismod.c
+++ b/checkpolicy/test/dismod.c
@@ -755,7 +755,12 @@ static void link_module(policydb_t * base, FILE * out_fp)
return;
}
printf("\nModule filename: ");
- fgets(module_name, sizeof(module_name), stdin);
+ if (fgets(module_name, sizeof(module_name), stdin) == NULL) {
+ fprintf(stderr, "fgets failed at line %d: %s\n", __LINE__,
+ strerror(errno));
+ exit(1);
+ }
+
module_name[strlen(module_name) - 1] = '\0'; /* remove LF */
if (module_name[0] == '\0') {
return;
@@ -884,7 +889,12 @@ int main(int argc, char **argv)
menu();
for (;;) {
printf("\nCommand (\'m\' for menu): ");
- fgets(ans, sizeof(ans), stdin);
+ if (fgets(ans, sizeof(ans), stdin) == NULL) {
+ fprintf(stderr, "fgets failed at line %d: %s\n", __LINE__,
+ strerror(errno));
+ continue;
+ }
+
switch (ans[0]) {
case '1':
@@ -951,7 +961,11 @@ int main(int argc, char **argv)
case 'f':
printf
("\nFilename for output (<CR> for screen output): ");
- fgets(OutfileName, sizeof(OutfileName), stdin);
+ if (fgets(OutfileName, sizeof(OutfileName), stdin) == NULL) {
+ fprintf(stderr, "fgets failed at line %d: %s\n", __LINE__,
+ strerror(errno));
+ break;
+ }
OutfileName[strlen(OutfileName) - 1] = '\0'; /* fix_string (remove LF) */
if (strlen(OutfileName) == 0)
out_fp = stdout;
diff --git a/checkpolicy/test/dispol.c b/checkpolicy/test/dispol.c
index 9d66358..0333bcc 100644
--- a/checkpolicy/test/dispol.c
+++ b/checkpolicy/test/dispol.c
@@ -449,7 +449,11 @@ int main(int argc, char **argv)
menu();
for (;;) {
printf("\nCommand (\'m\' for menu): ");
- fgets(ans, sizeof(ans), stdin);
+ if (fgets(ans, sizeof(ans), stdin) == NULL) {
+ fprintf(stderr, "fgets failed at line %d: %s\n", __LINE__,
+ strerror(errno));
+ continue;
+ }
switch (ans[0]) {
case '1':
@@ -476,7 +480,11 @@ int main(int argc, char **argv)
break;
case '7':
printf("name? ");
- fgets(ans, sizeof(ans), stdin);
+ if (fgets(ans, sizeof(ans), stdin) == NULL) {
+ fprintf(stderr, "fgets failed at line %d: %s\n", __LINE__,
+ strerror(errno));
+ break;
+ }
ans[strlen(ans) - 1] = 0;
name = malloc((strlen(ans) + 1) * sizeof(char));
@@ -487,7 +495,11 @@ int main(int argc, char **argv)
strcpy(name, ans);
printf("state? ");
- fgets(ans, sizeof(ans), stdin);
+ if (fgets(ans, sizeof(ans), stdin) == NULL) {
+ fprintf(stderr, "fgets failed at line %d: %s\n", __LINE__,
+ strerror(errno));
+ break;
+ }
ans[strlen(ans) - 1] = 0;
if (atoi(ans))
@@ -514,7 +526,11 @@ int main(int argc, char **argv)
case 'f':
printf
("\nFilename for output (<CR> for screen output): ");
- fgets(OutfileName, sizeof(OutfileName), stdin);
+ if (fgets(OutfileName, sizeof(OutfileName), stdin) == NULL) {
+ fprintf(stderr, "fgets failed at line %d: %s\n", __LINE__,
+ strerror(errno));
+ break;
+ }
OutfileName[strlen(OutfileName) - 1] = '\0'; /* fix_string (remove LF) */
if (strlen(OutfileName) == 0)
out_fp = stdout;
--
1.9.1
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2015-02-26 13:31 ` Fwd: [PATCH] fgets function warnings fix Stephen Smalley
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