-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Could someone with IA64 expertise have a look at #508397 in dietlibc please? Quoting full text for the benefit of the list.
On Sun, 28 Dec 2008 at 15:35:23 +0000, Simon McVittie wrote: > reopen 508397 > retitle 508397 dietlibc: umount2 still undefined on ia64, and umount is wrong > block 509874 by 508397 > thanks > > Bug#508397 in dietlibc is still not fixed on ia64, causing the FTBFS > that is #509874. I am not an expert on alpha or ia64 (and don't own an > example of either) but my interpretation of the problem is: > > * Case 1: Typical architectures like i386 have syscalls sys_umount(path, > flags) > and sys_oldumount(path), corresponding to the C library functions > umount2(path, flags) and umount(path). __NR_umount2 corresponds to > sys_umount and __NR_umount corresponds to sys_oldumount. dietlibc > always supported this case. > > * Case 2: Old versions of Linux only have a syscall equivalent to the > modern sys_oldumount(path) and umount(path). __NR_umount corresponds to > what we would now call sys_oldumount and __NR_umount2 is absent. > dietlibc always supported this case, and would simply not provide the > umount2 API (but would still declare it in sys/mount.h, which is > arguably a bug). > > * Case 3: alpha instead has __NR_umount corresponding to sys_umount, and > __NR_oldumount => sys_oldumount. Micah's patch in dietlibc 0.31-1.1 fixed > this case. > > (Side note: I have no idea what the justification was for making > alpha inconsistent in the kernel headers) > > * Case 4: ia64 never had oldumount. __NR_umount corresponds to > sys_umount(path, flags) and there is no syscall that only takes a path. > If you just look at the syscall numbers, this case is > indistinguishable from case 2 :-( > > (Side note: Linux kernel people could have solved this by calling this > syscall __NR_umount2. *shrug* I'm not a kernel hacker, their ways are a > mystery to me.) > > A quick way to fix this for Debian would be to check for defined(__ia64__) > in umount.S and umount2.S, although I doubt upstream would like this. > > In the IA-64 case, an extern symbol for umount also still needs generating > somehow, maybe by adding a trivial ia64/umount.c which implements it as > a call to umount2 (upstream would probably prefer it in assembler, but I > don't speak fluent assembler). > > I attach a proof-of-concept patch. I haven't tested it with util-vserver, > but it compiles on merulo, and the resulting dietlibc.a contains exactly one > definition each for umount and umount2. > > Regards, > Simon > diffstat for dietlibc_0.31-1.1 dietlibc_0.31-1.2 > > debian/diff/0012-umount-ia64.diff | > 14 ++++++++++ > dietlibc-0.31/debian/changelog | > 10 +++++++ > dietlibc-0.31/debian/diff/0011-undefined-symbol-umount2-alpha-ia64.diff | > 4 +- > 3 files changed, 26 insertions(+), 2 deletions(-) > > diff -u dietlibc-0.31/debian/changelog dietlibc-0.31/debian/changelog > --- dietlibc-0.31/debian/changelog > +++ dietlibc-0.31/debian/changelog > @@ -1,3 +1,13 @@ > +dietlibc (0.31-1.2) UNRELEASED; urgency=low > + > + * Untested proof-of-concept > + * debian/diff/0011-undefined-symbol-umount2-alpha-ia64.diff: > + treat __NR_umount as the 2-argument version on ia64 (closes: #508397) > + * debian/diff/0012-umount-ia64.diff: provide an implementation of the > + 1-argument version of umount on ia64 > + > + -- Simon McVittie <[email protected]> Sun, 28 Dec 2008 15:16:27 +0000 > + > dietlibc (0.31-1.1) unstable; urgency=high > > * Non-maintainer upload. > diff -u > dietlibc-0.31/debian/diff/0011-undefined-symbol-umount2-alpha-ia64.diff > dietlibc-0.31/debian/diff/0011-undefined-symbol-umount2-alpha-ia64.diff > --- dietlibc-0.31/debian/diff/0011-undefined-symbol-umount2-alpha-ia64.diff > +++ dietlibc-0.31/debian/diff/0011-undefined-symbol-umount2-alpha-ia64.diff > @@ -5,7 +5,7 @@ > > +#if defined(__NR_oldumount) && defined(__NR_umount) > +syscall(oldumount,umount) > -+#else > ++#elif !defined(__ia64__) > syscall(umount,umount) > +#endif > --- a/syscalls.s/umount2.S 4 Jan 2003 22:21:48 -0000 1.2 > @@ -17,5 +17,5 @@ > +#if defined(__NR_umount2) > syscall(umount2,umount2) > -+#elif defined(__NR_oldumount) && defined(__NR_umount) > ++#elif defined(__NR_umount) && (defined(__NR_oldumount) || defined(__ia64__)) > +syscall(umount,umount2) > #endif > only in patch2: > unchanged: > --- dietlibc-0.31.orig/debian/diff/0012-umount-ia64.diff > +++ dietlibc-0.31/debian/diff/0012-umount-ia64.diff > @@ -0,0 +1,14 @@ > +--- a/ia64/Makefile.add 2008-12-28 15:13:51.000000000 +0000 > ++++ b/ia64/Makefile.add 2008-12-28 15:14:10.000000000 +0000 > +@@ -1,2 +1,2 @@ > + VPATH:=ia64:syscalls.s:$(VPATH) > +-LIBOBJ+=$(OBJDIR)/__time.o $(OBJDIR)/__waitpid.o $(OBJDIR)/__nice.o > $(OBJDIR)/__alarm.o > ++LIBOBJ+=$(OBJDIR)/__time.o $(OBJDIR)/__waitpid.o $(OBJDIR)/__nice.o > $(OBJDIR)/__alarm.o $(OBJDIR)/umount-wrapper.o > +--- /dev/null 2008-12-18 18:10:23.510503709 +0000 > ++++ b/ia64/umount-wrapper.c 2008-12-28 15:13:38.000000000 +0000 > +@@ -0,0 +1,5 @@ > ++#include <sys/mount.h> > ++ > ++int umount(const char *target) { > ++ return umount2(target, 0); > ++} -----BEGIN PGP SIGNATURE----- iD8DBQFJV6KRWSc8zVUw7HYRAldIAKCuQtbr6SE8tv6UfmzLyyWAwa2YwgCfTFNr sFoU6yXfJH/nRyI/X1gQ1Xg= =YKwf -----END PGP SIGNATURE----- -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". 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