Messages in this thread |  | | | Date | Mon, 19 Apr 2010 23:57:11 +0200 | | From | maximilian attems <> | | Subject | Re: [PATCH] fcntl.h: define AT_EACCESS |
| |
On Mon, Apr 19, 2010 at 02:47:29PM -0700, Andrew Morton wrote: > On Fri, 16 Apr 2010 05:08:00 +0200 > maximilian attems <max@stro.at> wrote: > > > noticed on a klibc build of dash that someone had left out that def: > > usr/dash/bltin/test.c:490: error: ___AT_EACCESS___ undeclared (first use in thiction) > > > > Cc: stable@kernel.org > > Cc: Ulrich Drepper <drepper@redhat.com> > > Cc: H. Peter Anvin <hpa@zytor.com> > > Cc: Herbert Xu <herbert@gondor.apana.org.au> > > Signed-off-by: maximilian attems <max@stro.at> > > --- > > include/linux/fcntl.h | 2 ++ > > 1 files changed, 2 insertions(+), 0 deletions(-) > > > > diff --git a/include/linux/fcntl.h b/include/linux/fcntl.h > > index 8603740..8bb001d 100644 > > --- a/include/linux/fcntl.h > > +++ b/include/linux/fcntl.h > > @@ -39,6 +39,8 @@ > > #define AT_REMOVEDIR 0x200 /* Remove directory instead of > > unlinking file. */ > > #define AT_SYMLINK_FOLLOW 0x400 /* Follow symbolic links. */ > > +#define AT_EACCESS 0x200 /* Test access permitted for > > + effective IDs, not real IDs. */ > > > > I'm all confused. > > The affects sys_faccesat(), yes? But sys_faccesat() never gets passed > a `flags' argument so how does the behaviour which the FACCESSAT(2) > manpage describes get implemented? > > This patch doesn't actually change kernel behaviour, so how can setting > AT_EACCESS change any syscall's actions? > > It's a bit of a worry that the proposed value for AT_EACCESS duplicates > AT_REMOVEDIR. I guess that, despite apeparances, they're different > namespaces. Any thoughts on the implications of this?
glibc fcntl.h defines AT_EACCESS in the same way as aboves patch, concerning the implementation, others should know better.
the dash code calling faccessat has the 4 params, klibc faccessat had only 3 args, guess nobody had used it before.
the relevant dash code reads: #ifdef HAVE_FACCESSAT static int test_file_access(const char *path, int mode) { return !faccessat(AT_FDCWD, path, mode, AT_EACCESS); } #else /* HAVE_FACCESSAT */
|  |