> Frank Hofmann <[EMAIL PROTECTED]> wrote: > > > On Thu, 17 May 2007, Joerg Schilling wrote: > > > > > [EMAIL PROTECTED] wrote: > > > > > >> - you cannot mix 64 bit & 32 bit > > >> - you cannot use code from libc in the kernel > because there's > > >> no guarantee that that code will work in > kernel context(!) > > >> > > >> > > >> The kernel has a strstr() of its own, so you'll > need to just call > > >> that. > > > > > > Many of the libc functions have to repect the > same rules as the kernel > > > and the kernel implementations may also fail, see > bug 6489267 where > > > strncat() from the kernel caused a panic because > of accessing a byte > > > bejond the permitted range. > > > > The str* functions just sometimes don't quite do > what one might naively > > think they'd do. Try finding/fixing the bugs in > this one: > > > > char str[100]; > > > > memset(str, '\0', 100); /* clear string memory > */ > > > > pgsz = sysconf(_SC_PAGESIZE); > > buf = mmap(NULL, pgsz, PROT_READ | PROT_WRITE, > > MAP_ANON | MAP_PRIVATE, 0, 0); > > memset(buf, 'a', pgsz); /* page now filled with > 'a' */ > > > > strlcat(str, buf, 1); /* append single byte from > buf */ > > strncat(str, buf + pgsz, 0); /* doesn't really do > anything */ > > > > Both str*cat calls will crash. Go figure. > > The strlcat() case looks like a usage error as > strlcat() returns the > number of bytes that would be copied by strcat(). As > there is no > null byte at the end of the string, it accesses too > much from buf. > > The strncat() case looks different. > > BTW: in the POSIX mailing list, there is just a > discussion that even str*() > functions need to respect range limits. > > Jörg > > -- > EMail:[EMAIL PROTECTED] (home) Jörg > Schilling D-13353 Berlin > [EMAIL PROTECTED] (uni) > [EMAIL PROTECTED] (work) Blog: > http://schily.blogspot.com/ > URL: http://cdrecord.berlios.de/old/private/ > ftp://ftp.berlios.de/pub/schily > _______________________________________________ > opensolaris-discuss mailing list > opensolaris-discuss@opensolaris.org >
Thanks to all where can I find the POSIX mailing list This message posted from opensolaris.org _______________________________________________ opensolaris-discuss mailing list opensolaris-discuss@opensolaris.org
