Home » Mailing list archives » linux-kernel » 2007 » March » 21

Re: [PATCH] Complain about missing system calls.

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[view original message]
From: David Woodhouse
Subject: [PATCH] Complain about missing system calls.
Date: Thursday, March 8, 2007 - 4:01 pm

Most system calls seem to get added to i386 first. This patch
automatically generates a warning for any new system call which is
implemented on i386 but not the architecture currently being compiled.
On PowerPC at the moment, for example, it results in these warnings:
init/missing_syscalls.h:935:3: warning: #warning syscall sync_file_range not implemented
init/missing_syscalls.h:947:3: warning: #warning syscall getcpu not implemented
init/missing_syscalls.h:950:3: warning: #warning syscall epoll_pwait not implemented

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

index 0154aea..826433b 100644
--- a/init/Makefile
+++ b/init/Makefile
@@ -2,7 +2,7 @@
 # Makefile for the linux kernel.
 #
 
-obj-y                          := main.o version.o mounts.o
+obj-y                          := main.o version.o mounts.o missing_syscalls.o
 ifneq ($(CONFIG_BLK_DEV_INITRD),y)
 obj-y                          += noinitramfs.o
 else
@@ -16,11 +16,12 @@ mounts-$(CONFIG_BLK_DEV_INITRD)	+= do_mounts_initrd.o
 mounts-$(CONFIG_BLK_DEV_MD)	+= do_mounts_md.o
 
 # files to be removed upon make clean
-clean-files := ../include/linux/compile.h
+clean-files := ../include/linux/compile.h $(obj)/missing_syscalls.h
 
 # dependencies on generated files need to be listed explicitly
 
 $(obj)/version.o: include/linux/compile.h
+$(obj)/missing_syscalls.o: $(obj)/missing_syscalls.h include/linux/compile.h FORCE
 
 # compile.h changes depending on hostname, generation number, etc,
 # so we regenerate it always.
@@ -31,3 +32,13 @@ include/linux/compile.h: FORCE
 	@echo '  CHK     $@'
 	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkcompile_h $@ \
 	"$(UTS_MACHINE)" "$(CONFIG_SMP)" "$(CONFIG_PREEMPT)" "$(CC) $(CFLAGS)"
+
+
+quiet_cmd_missing_syscalls = GEN     $@
+      cmd_missing_syscalls = sed -n '/^\#define/s/[^_]*__NR_\([^[:space:]]*\).*/\
+	\#if !defined (__NR_\1) \&\& !defined (__IGNORE_\1)\n\
+	\#warning syscall \1 not implemented\n\
+	\#endif/p' $(srctree)/include/asm-i386/unistd.h ...
[ message continues ]
[view original message]
From: David Miller
Subject: Re: [PATCH] Complain about missing system calls.
Date: Thursday, March 8, 2007 - 5:14 pm

From: David Woodhouse <dwmw2@infradead.org>

David, thanks for this __incredibly__ __useful__ patch.  I kicked it
around on sparc64 and found some more ignores to add, see below.

The vast majority of them vector to sys_ni_syscall in the i386 syscall
table.

sys_ugetrlimit is only necessary if the platform started out
using the non-SuS compliant sys_old_getrlimit()

The rest, like ioperm, iopl, modify_ldt, et al. are i386
specific.

Signed-off-by: David S. Miller <davem@davemloft.net>

--- a/init/missing_syscalls.c.ORIG	2007-03-08 16:11:00.000000000 -0800
+++ b/init/missing_syscalls.c	2007-03-08 16:02:30.000000000 -0800
@@ -18,6 +18,22 @@
 #endif
 
 /* i386-specific or historical system calls */
+#define __IGNORE_break
+#define __IGNORE_stty
+#define __IGNORE_gtty
+#define __IGNORE_ftime
+#define __IGNORE_prof
+#define __IGNORE_lock
+#define __IGNORE_mpx
+#define __IGNORE_ulimit
+#define __IGNORE_profil
+#define __IGNORE_ioperm
+#define __IGNORE_iopl
+#define __IGNORE_idle
+#define __IGNORE_modify_ldt
+#define __IGNORE_getpmsg
+#define __IGNORE_putpmsg
+#define __IGNORE_ugetrlimit
 #define __IGNORE_mmap2
 #define __IGNORE_vm86
 #define __IGNORE_vm86old
-


[ message continues ]
[view original message]
From: David Woodhouse
Subject: Re: [PATCH] Complain about missing system calls.
Date: Thursday, March 8, 2007 - 5:18 pm

Thanks for the update. Quite why the PowerPC kernel defines system call
numbers for all of these I have no idea :)

-- 
dwmw2

-


[ message continues ]
[view original message]
From: Sam Ravnborg
Subject: Re: [PATCH] Complain about missing system calls.
Date: Tuesday, March 20, 2007 - 5:12 am

Could it make sense to keep this in arch specific header files?
So when we fiddle with ARM we do not impact SPARC etc.
And in this way ARCH specific changes are kept in ARCH specific files.

For the "Ignore historical" part this should be in a common file I think.

So in other words:

init/missing_syscalls.h	=> Contains common stuff and include:
include/asm/missing_syscalls.h => contains ARCH specific stuff.


	Sam
-


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[view original message]
From: Anton Blanchard
Subject: Re: [PATCH] Complain about missing system calls.
Date: Thursday, March 8, 2007 - 8:31 pm

Love it!


BTW while unistd.h may refer to sys_iopl etc, the actual syscall is sent
to ni_syscall in most of these useless cases.

Anton
-


[ message continues ]
[view original message]
From: Russell King
Subject: Re: [PATCH] Complain about missing system calls.
Date: Friday, March 9, 2007 - 1:43 am

You might also like to add:

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

since I did resolve the issues with getting a sed expression which
did the right thing, rather than your for loop, awk, echo, and
providing a way to ignore the lack of certain syscall numbers...

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:
-


[ message continues ]
[view original message]
From: Andi Kleen
Subject: Re: [PATCH] Complain about missing system calls.
Date: Friday, March 9, 2007 - 9:11 am

I think a better solution would be to finally switch to auto generated
system call tables for newer system calls. The original reason why the
architectures have different system call numbers -- compatibility with
another "native" Unix -- is completely obsolete now. This leaves only
minor differences of compat stub vs non compat stub and a few
architecture specific calls.

Of course the existing syscall numbers can't be changed, but for all new 
calls one could just add automatically for everybody.

A global table with two entries (compat and non compat) and a per arch 
override table should be sufficient.

Comments?

-Andi
-


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[view original message]
From: Jan-Benedict Glaw
Subject: Re: [PATCH] Complain about missing system calls.
Date: Friday, March 9, 2007 - 9:38 am

Not everybody has a simple indexed list of pointers :)  For example,
for vax-linux, we use a struct per syscall with the expected number of
on-stack longwords for the call.

So if something "new" is coming up, please keep in mind that it should
be flexible enough to represent that. :)

MfG, JBG

--=20
      Jan-Benedict Glaw      jbglaw@lug-owl.de              +49-172-7608481
Signature of:         "really soon now":      an unspecified period of time=
, likly to
the second  :                                 be greater than any reasonabl=
e definition
                                              of "soon".

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[view original message]
From: Andi Kleen
Subject: Re: [PATCH] Complain about missing system calls.
Date: Friday, March 9, 2007 - 12:00 pm

Are there plans to merge vax any time soon to mainline? 

Normally we don't care very much about out of tree code, especially
if it adds complexity like this.

But I suspect s390 would need number of arguments anyways.

-Andi
-


[ message continues ]
[view original message]
From: Jan-Benedict Glaw
Subject: Re: [PATCH] Complain about missing system calls.
Date: Friday, March 9, 2007 - 12:35 pm

Well...  That depends :)  For now, I'd prefer to stay out of mainline,
until we're having gcc-trunk with a current GNU libc up'n'running.
Until then, I plan to at least break the complete ABI once (drop old

Sure, but at least mentioning that there's more than only a simple
table of function pointers may or may not help to *plan* the code to

Any they're already merged. Yay :)

MfG, JBG

--=20
      Jan-Benedict Glaw      jbglaw@lug-owl.de              +49-172-7608481
  Signature of:                           Wenn ich wach bin, tr=C3=A4ume ic=
h.
  the second  :

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[view original message]
From: Martin Schwidefsky
Subject: Re: [PATCH] Complain about missing system calls.
Date: Saturday, March 10, 2007 - 2:58 am

I can't quite follow that line of thought. Why does s390 need the number
of arguments? The wrapper of a compat system call implicitly knows how
many arguments a system calls to do the conversion. For a normal system
call we just call the function. Random example sys_read: the user space
loads the arguments to register %r2, %r3, %r4 and calls the system. The
register are not touched until sys_read is reached. Only sys_read cares
about the number of arguments in this case.

-- 
blue skies,              IBM Deutschland Entwicklung GmbH
   Martin                Vorsitzender des Aufsichtsrats: Johann Weihen
                         Geschäftsführung: Herbert Kircher
Martin Schwidefsky       Sitz der Gesellschaft: Böblingen
Linux on zSeries         Registergericht: Amtsgericht Stuttgart,
   Development           HRB 243294

"Reality continues to ruin my life." - Calvin.


-


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From: H. Peter Anvin
Subject: Re: [PATCH] Complain about missing system calls.
Date: Friday, March 9, 2007 - 12:40 pm

I discussed with Al Viro a while ago about using something like the 
SYSCALLS.def file from klibc as the source format for the system calls. 
  That would deal very flexibly with almost all kinds of stub generation.

	-hpa
-


[ message continues ]
[view original message]
From: Russell King
Subject: Re: [PATCH] Complain about missing system calls.
Date: Friday, March 9, 2007 - 1:13 pm

Hopefully with this idea in place, we can spot new syscalls before
the final release of the kernel (maybe kautobuild can help there)
and fix any silly system call argument ordering which requires
different architectures to have different syscall prototypes (eg,
sys_arm_fadvise64_64 vs sys_fadvise64_64, sys_arm_sync_file_range vs
sys_sync_file_range).

Otherwise the SYSCALLS.def file will probably end up being full of
ifdefs.

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:
-


[ message continues ]
[view original message]
From: H. Peter Anvin
Subject: Re: [PATCH] Complain about missing system calls.
Date: Friday, March 9, 2007 - 1:52 pm

... which exactly mirrors the pain and suffering which libc maintainers 
have to deal with.  The amount of time I spent per line of code in klibc 
is quite high, in part because I wanted it to be as self-porting as was 
possible.  I've really tried to avoid arch-specific hacks, and yet there 
are more there than there should be, in large part because of unusable 
or missing kernel header exports.

	-hpa
-


[ message continues ]
[view original message]
From: Benjamin Herrenschmidt
Subject: Re: [PATCH] Complain about missing system calls.
Date: Friday, March 9, 2007 - 9:47 am

We need additional gunk for syscalls that can be called from SPEs on
cell

Ben.


-


[ message continues ]
[view original message]
From: Andi Kleen
Subject: Re: [PATCH] Complain about missing system calls.
Date: Friday, March 9, 2007 - 11:54 am

Can that gunk not be auto generated?

I know s390 does in some cases, but it looks quite auto generatable to me.

-


[ message continues ]
[view original message]
From: Martin Schwidefsky
Subject: Re: [PATCH] Complain about missing system calls.
Date: Saturday, March 10, 2007 - 2:51 am

The system call tables and the compat wrapper are all manually created.
If we manage to get the prototypes for the system calls in a parseable
format at least the compat wrappers could be auto-generated. I see two
pitfalls: 1) some compat system calls are directly wired to the system
call table while others need the compat_wrapper detour, 2) override of
system calls with "meta" system calls like sys_socket or sys_ipc.

-- 
blue skies,              IBM Deutschland Entwicklung GmbH
   Martin                Vorsitzender des Aufsichtsrats: Johann Weihen
                         Geschäftsführung: Herbert Kircher
Martin Schwidefsky       Sitz der Gesellschaft: Böblingen
Linux on zSeries         Registergericht: Amtsgericht Stuttgart,
   Development           HRB 243294

"Reality continues to ruin my life." - Calvin.


-


[ message continues ]
[view original message]
From: David Woodhouse
Subject: Re: [PATCH] Complain about missing system calls.
Date: Friday, March 9, 2007 - 10:20 am

Counterexample: sys_epoll_pwait.

It'd be nice if it were that simple.

It'd also be nice if people stopped thinking it was that simple :)

-- 
dwmw2

-


[ message continues ]
[view original message]
From: Andrew Morton
Subject: Re: [PATCH] Complain about missing system calls.
Date: Monday, March 19, 2007 - 4:42 pm

On Thu, 08 Mar 2007 23:01:13 +0000

hm, did you try running this on x86_64?

In file included from init/missing_syscalls.c:73:
init/missing_syscalls.h:23:3: warning: #warning syscall waitpid not implemented
init/missing_syscalls.h:68:3: warning: #warning syscall umount not implemented
init/missing_syscalls.h:77:3: warning: #warning syscall stime not implemented
init/missing_syscalls.h:104:3: warning: #warning syscall nice not implemented
init/missing_syscalls.h:146:3: warning: #warning syscall signal not implemented
init/missing_syscalls.h:203:3: warning: #warning syscall sigaction not implemented
init/missing_syscalls.h:206:3: warning: #warning syscall sgetmask not implemented
init/missing_syscalls.h:209:3: warning: #warning syscall ssetmask not implemented
init/missing_syscalls.h:218:3: warning: #warning syscall sigsuspend not implemented
init/missing_syscalls.h:221:3: warning: #warning syscall sigpending not implemented
init/missing_syscalls.h:269:3: warning: #warning syscall readdir not implemented
init/missing_syscalls.h:308:3: warning: #warning syscall socketcall not implemented
init/missing_syscalls.h:353:3: warning: #warning syscall ipc not implemented
init/missing_syscalls.h:359:3: warning: #warning syscall sigreturn not implemented
init/missing_syscalls.h:380:3: warning: #warning syscall sigprocmask not implemented
init/missing_syscalls.h:404:3: warning: #warning syscall bdflush not implemented
init/missing_syscalls.h:422:3: warning: #warning syscall _llseek not implemented
init/missing_syscalls.h:428:3: warning: #warning syscall _newselect not implemented
init/missing_syscalls.h:800:3: warning: #warning syscall statfs64 not implemented
init/missing_syscalls.h:803:3: warning: #warning syscall fstatfs64 not implemented
init/missing_syscalls.h:947:3: warning: #warning syscall getcpu not implemented
init/missing_syscalls.h:950:3: warning: #warning syscall epoll_pwait not implemented
init/missing_syscalls.h:953:3: warning: #warning syscall lutimesat not ...
[ message continues ]
[view original message]
From: David Woodhouse
Subject: Re: [PATCH] Complain about missing system calls.
Date: Tuesday, March 20, 2007 - 12:43 am

I don't have any. I only tested it on PowerPC and i386. Others then
provided more exclusions for SPARC and maybe ARM, although I'm not sure
you have the latter yet. It's not hard to add extra exclusions.

-- 
dwmw2

-


[ message continues ]
[view original message]
From: David Howells
Subject: Re: [PATCH] Complain about missing system calls.
Date: Tuesday, March 20, 2007 - 3:51 am

You could always have asked to borrow my test box.

David
-


[ message continues ]
[view original message]
From: Russell King
Subject: Re: [PATCH] Complain about missing system calls.
Date: Tuesday, March 20, 2007 - 3:56 am

Some of the ones which come up on x86_64 also come up on ARM for the
same reason; they're obsolete system calls which probably shouldn't
be implemented on anything but legacy i386.  Things like waitpid, etc.

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:
-


[ message continues ]
[view original message]
From: David Woodhouse
Subject: Re: [PATCH] Complain about missing system calls.
Date: Wednesday, March 21, 2007 - 4:25 am

git://git.infradead.org/~dwmw2/syscalls-2.6.git

Should make it quieter on ARM and x86_64, and includes Stéphane's patch
to make it work with dash.

-- 
dwmw2

-


[ message continues ]
Previous thread: [PATCH] drivers: PMC MSP71xx TWI driver by Marc St-Jean on Thursday, March 8, 2007 - 4:24 pm. (1 message)

Next thread: [GIT PULL] please pull infiniband.git by Roland Dreier on Thursday, March 8, 2007 - 4:50 pm. (1 message)