URL: https://github.com/SSSD/sssd/pull/96
Author: lslebodn
Title: #96: CONFDB: Supress clang false passitive warnings
Action: opened
PR body:
"""
The errno is macro expandee into '(*__errno_location ())'.
The reason is that errno is private in glibc and and the
function __errno_location return address of private errno.
sh$ objdump -T /lib64/libc.so.6 | grep errno
00000010 g D .tbss 00000004 GLIBC_PRIVATE errno
000208a0 g DF .text 00000011 GLIBC_2.2.5 __errno_location
001366b0 g DF .text 0000005f GLIBC_2.2.5 clnt_sperrno
00136710 g DF .text 00000074 GLIBC_2.2.5 clnt_perrno
00000064 g D .tbss 00000004 GLIBC_PRIVATE __h_errno
0011aad0 g DF .text 00000011 GLIBC_2.2.5 __h_errno_location
It looks like clang static analyzer assume that value can be
changed due to function call.
errno = 0;
val = strtol(values[0], NULL, 0);
// Taking true branch => assuming "errno != 0"
if (errno) {
ret = errno;
// errno was stored to ret but clang later assumes
// that ret can be 0
goto failed;
"""
To pull the PR as Git branch:
git remote add ghsssd https://github.com/SSSD/sssd
git fetch ghsssd pull/96/head:pr96
git checkout pr96
From 8a80082e0e8a3c85f6f491ab5eca5a967c4195ae Mon Sep 17 00:00:00 2001
From: Lukas Slebodnik <lsleb...@redhat.com>
Date: Sat, 26 Nov 2016 17:07:07 +0100
Subject: [PATCH] CONFDB: Supress clang false passitive warnings
The errno is macro expandee into '(*__errno_location ())'.
The reason is that errno is private in glibc and and the
function __errno_location return address of private errno.
sh$ objdump -T /lib64/libc.so.6 | grep errno
00000010 g D .tbss 00000004 GLIBC_PRIVATE errno
000208a0 g DF .text 00000011 GLIBC_2.2.5 __errno_location
001366b0 g DF .text 0000005f GLIBC_2.2.5 clnt_sperrno
00136710 g DF .text 00000074 GLIBC_2.2.5 clnt_perrno
00000064 g D .tbss 00000004 GLIBC_PRIVATE __h_errno
0011aad0 g DF .text 00000011 GLIBC_2.2.5 __h_errno_location
It looks like clang static analyzer assume that value can be
changed due to function call.
errno = 0;
val = strtol(values[0], NULL, 0);
// Taking true branch => assuming "errno != 0"
if (errno) {
ret = errno;
// errno was stored to ret but clang later assumes
// that ret can be 0
goto failed;
---
src/confdb/confdb.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/src/confdb/confdb.c b/src/confdb/confdb.c
index 512d93f..ac75852 100644
--- a/src/confdb/confdb.c
+++ b/src/confdb/confdb.c
@@ -448,8 +448,8 @@ int confdb_get_int(struct confdb_ctx *cdb,
errno = 0;
val = strtol(values[0], NULL, 0);
- if (errno) {
- ret = errno;
+ ret = errno;
+ if (ret) {
goto failed;
}
@@ -504,8 +504,8 @@ long confdb_get_long(struct confdb_ctx *cdb,
errno = 0;
val = strtol(values[0], NULL, 0);
- if (errno) {
- ret = errno;
+ ret = errno;
+ if (ret) {
goto failed;
}
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