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This is an automatically generated e-mail. To reply, visit:
<a href="https://reviewboard.asterisk.org/r/4530/">https://reviewboard.asterisk.org/r/4530/</a>
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<p style="margin-top: 0;">On March 29th, 2015, 9:11 p.m. CDT, <b>Matt Jordan</b> wrote:</p>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">So, small problem with this change. When compiling with gcc 4.8.2, I get the following warning:
In function ‘read’,
inlined from ‘inotify_daemon’ at stdtime/localtime.c:380:6:
/usr/include/x86_64-linux-gnu/bits/unistd.h:42:2: error: call to ‘__read_chk_warn’ declared with attribute warning: read called with bigger length than size of the destination buffer [-Werror]
return __read_chk_warn (__fd, __buf, __nbytes, __bos0 (__buf));
Interestingly, the build agents didn't kick this back. But we'll need to find a way to get this fixed for gcc as well.</pre>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">So, this is interesting. Looking at unistd.h:
extern ssize_t __read_chk (int __fd, void *__buf, size_t __nbytes,
size_t __buflen) __wur;
extern ssize_t __REDIRECT (__read_alias, (int __fd, void *__buf,
size_t __nbytes), read) __wur;
extern ssize_t __REDIRECT (__read_chk_warn,
(int __fd, void *__buf, size_t __nbytes,
size_t __buflen), __read_chk)
__wur __warnattr ("read called with bigger length than size of "
"the destination buffer");
__fortify_function __wur ssize_t
read (int __fd, void *__buf, size_t __nbytes)
{
if (__bos0 (__buf) != (size_t) -1)
{
if (!__builtin_constant_p (__nbytes))
return __read_chk (__fd, __buf, __nbytes, __bos0 (__buf));
if (__nbytes > __bos0 (__buf))
return __read_chk_warn (__fd, __buf, __nbytes, __bos0 (__buf));
}
return __read_alias (__fd, __buf, __nbytes);
}
That is, if __nbytes is greater than the result of GCC's built-in object size (https://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html) for the struct, we'll kick back a warning.
As it turns out, this is because there is an error in the code here - we're passing the address of the pointer to the struct, not iev, which is a pointer to the struct. Hence, the number of bytes is probably going to be lot larger than the number of bytes that make up a pointer! Changing this to just read from the pointer to the struct fixes the warning.</pre>
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<p>- Matt</p>
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<p>On March 29th, 2015, 8:52 p.m. CDT, Diederik de Groot wrote:</p>
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<div>Review request for Asterisk Developers.</div>
<div>By Diederik de Groot.</div>
<p style="color: grey;"><i>Updated March 29, 2015, 8:52 p.m.</i></p>
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<b style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Bugs: </b>
<a href="https://issues.asterisk.org/jira/browse/ASTERISK-24917">ASTERISK-24917</a>
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<b style="color: #575012; font-size: 10pt;">Repository: </b>
Asterisk
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<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Description </h1>
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<pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">clang's static analyzer will throw quite a number warnings / errors during compilation, some of which can be very helpfull in finding corner-case bugs\nclang compiler warning:-Wgnu-variable-sized-type-not-at-end</pre>
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<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Diffs</b> </h1>
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<li>/branches/13/main/stdtime/localtime.c <span style="color: grey">(433444)</span></li>
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<p><a href="https://reviewboard.asterisk.org/r/4530/diff/" style="margin-left: 3em;">View Diff</a></p>
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