svn commit: r235266 - head/lib/libc/stdlib
ache at FreeBSD.ORG
Fri May 11 17:56:26 UTC 2012
On Fri, May 11, 2012 at 08:04:12PM +0300, Konstantin Belousov wrote:
> On Fri, May 11, 2012 at 06:54:32PM +0400, Andrey Chernov wrote:
> > Thanks, but in this two places old errno value should be saved across
> > free() because free() may damage it:
> I do not agree. free() cannot change errno.
Perhaps I forget something, so please refer to standard stating that.
IEEE Std 1003.1-2008 says that "No errors are defined." in the ERRORS
section, but states that beforehand:
"if the argument does not match a pointer earlier returned by a function
in POSIX.1-2008 that allocates memory as if by malloc(), or if the space has
been deallocated by a call to free() or realloc(), the behavior is
Any use of a pointer that refers to freed space results in undefined
The DESCRIPTION is updated to clarify that if the pointer returned is not
by a function that allocates memory as if by malloc(), then the behavior
So that "undefined behavior" case still can modify errno.
(Some internal syscalls (like munmap etc) could produce errno. In any
case it is very implemetation defined.)
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