Hi, found something which looks for me like a kernel/glibc syscall mismatch. At least the parameter list of "readlink" is different in the kernel compared to glibc, POSIX and linux-man-pages. I'm not quite sure if this difference was intended or not ... man 3p readlink: ssize_t readlink(const char *restrict path, char *restrict buf, size_t bufsize); http://www.opengroup.org/onlinepubs/000095399/functions/readlink.html: size_t readlink(const char *restrict path, char *restrict buf, size_t bufsize); glibc (/usr/include/unistd.h): size_t readlink (__const char *__restrict __path, char *__restrict __buf, size_t man 2 readlink: ssize_t readlink(const char *path, char *buf, size_t bufsiz); ^^^^^^ linux-2.6/include/linux/syscalls.h: asmlinkage long sys_readlink(const char __user *path, char __user *buf, int bufsiz); ^^^ All readlink prototypes, expect the one in the kernel, have an unsigned buffer size. Even the readlink(2) man-page, which also describes an error statement like this: EINVAL bufsiz is not positive. Note: the same man-page defined bufsiz as type of size_t (unsigned). While reviewing LTP i discovered that the "readlink03" syscall test contains a testcase to do a functional error-path test for "EINVAL bufsiz is not positive". This testcase is using the glibc readlink() interface, which cause a unsigned cast of the value "-1" and let the testcase fail (actually due to gcc/glibc fortify checks and cause a __chk_fail()). Before workarounding the testcase, or not applying -D_FORTIFY_SOURCE=2 on LTP build, i try to understand if there is any reason for this mismatch between kernel and glibc/POSIX. Regarding the man-page, i'm quite certain this was a copy&paste-error by coping the prototype from the POSIX man-page. Even sys_readlinkat(), which got introduced a long time after sys_readlink(), got a signed buffer size. Intended? In the rare case all this was unintended, find patches for kernel, man-pages and LTP to change the kernel readlink syscall interface to a unsigned buffer size. Thoughts? best regards, Daniel -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
