Re: [PATCH 2/2] selftests/userfaultfd: improve syscall number definition
On 09/22/2015 04:45 AM, Andre Przywara wrote: > At the moment the userfaultfd test program only supports x86 and an > architecture called "powewrpc" ;-) > Fix that typo and add the syscall numbers for other architectures as > well. > Also as in an ideal world a syscall number should come from the system > header file , include that header and guard the explicit > syscall number section below to avoid redefinitions. > > Signed-off-by: Andre Przywara > --- > tools/testing/selftests/vm/userfaultfd.c | 13 - > 1 file changed, 12 insertions(+), 1 deletion(-) > > diff --git a/tools/testing/selftests/vm/userfaultfd.c > b/tools/testing/selftests/vm/userfaultfd.c > index 2c7cca6..63be27f 100644 > --- a/tools/testing/selftests/vm/userfaultfd.c > +++ b/tools/testing/selftests/vm/userfaultfd.c > @@ -65,16 +65,27 @@ > #include > #include > #include "../../../../include/uapi/linux/userfaultfd.h" > +#include > > +/* ideally the above user header provides that number, but ... */ > +#ifndef __NR_userfaultfd > #ifdef __x86_64__ > #define __NR_userfaultfd 323 > #elif defined(__i386__) > #define __NR_userfaultfd 374 > -#elif defined(__powewrpc__) > +#elif defined(__powerpc__) > #define __NR_userfaultfd 364 > +#elif defined(__ia64__) > +#define __NR_userfaultfd 1343 > +#elif defined(__arm__) > +#define __NR_userfaultfd 388 > +#elif defined(__aarch64__) > +/* this is from the generic syscall table, used also on other architectures > */ > +#define __NR_userfaultfd 283 > #else > #error "missing __NR_userfaultfd definition" > #endif > +#endif /* !__NR_userfaultfd */ > > static unsigned long nr_cpus, nr_pages, nr_pages_per_cpu, page_size; > > This is not okay. User-space shouldn't be (re)defining/duplicating syscall numbers. I can't take this patch. thanks, -- Shuah -- Shuah Khan Sr. Linux Kernel Developer Open Source Innovation Group Samsung Research America (Silicon Valley) shua...@osg.samsung.com | (970) 217-8978 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 2/2] selftests/userfaultfd: improve syscall number definition
On Tue, Sep 22, 2015 at 07:49:13AM -0600, Shuah Khan wrote: > On 09/22/2015 04:45 AM, Andre Przywara wrote: > > At the moment the userfaultfd test program only supports x86 and an > > architecture called "powewrpc" ;-) > > Fix that typo and add the syscall numbers for other architectures as > > well. > > Also as in an ideal world a syscall number should come from the system > > header file , include that header and guard the explicit > > syscall number section below to avoid redefinitions. > > > > Signed-off-by: Andre Przywara > > --- > > tools/testing/selftests/vm/userfaultfd.c | 13 - > > 1 file changed, 12 insertions(+), 1 deletion(-) > > > > diff --git a/tools/testing/selftests/vm/userfaultfd.c > > b/tools/testing/selftests/vm/userfaultfd.c > > index 2c7cca6..63be27f 100644 > > --- a/tools/testing/selftests/vm/userfaultfd.c > > +++ b/tools/testing/selftests/vm/userfaultfd.c > > @@ -65,16 +65,27 @@ > > #include > > #include > > #include "../../../../include/uapi/linux/userfaultfd.h" > > +#include > > > > +/* ideally the above user header provides that number, but ... */ > > +#ifndef __NR_userfaultfd > > #ifdef __x86_64__ > > #define __NR_userfaultfd 323 > > #elif defined(__i386__) > > #define __NR_userfaultfd 374 > > -#elif defined(__powewrpc__) > > +#elif defined(__powerpc__) > > #define __NR_userfaultfd 364 > > +#elif defined(__ia64__) > > +#define __NR_userfaultfd 1343 > > +#elif defined(__arm__) > > +#define __NR_userfaultfd 388 > > +#elif defined(__aarch64__) > > +/* this is from the generic syscall table, used also on other > > architectures */ > > +#define __NR_userfaultfd 283 > > #else > > #error "missing __NR_userfaultfd definition" > > #endif > > +#endif /* !__NR_userfaultfd */ > > > > static unsigned long nr_cpus, nr_pages, nr_pages_per_cpu, page_size; > > > > > > This is not okay. User-space shouldn't be (re)defining/duplicating > syscall numbers. I can't take this patch. -mm has already been updated to do exactly that. Syscall numbers end up hardcoded into userland binaries/libs somewhere, so it's not a bugfix but certainly it's a nice cleanup to remove the whole #ifdef block. Andre, could you see if linux-next (which includes -mm) works for you by just running "cd tools/testing/selftests/vm/ && make"? If there's any further change required could you diff it against linux-next? Thanks! Andrea -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 2/2] selftests/userfaultfd: improve syscall number definition
Hi Shuah, Andrea, On 22/09/15 15:06, Andrea Arcangeli wrote: > On Tue, Sep 22, 2015 at 07:49:13AM -0600, Shuah Khan wrote: >> On 09/22/2015 04:45 AM, Andre Przywara wrote: >>> At the moment the userfaultfd test program only supports x86 and an >>> architecture called "powewrpc" ;-) >>> Fix that typo and add the syscall numbers for other architectures as >>> well. >>> Also as in an ideal world a syscall number should come from the system >>> header file , include that header and guard the explicit >>> syscall number section below to avoid redefinitions. >>> >>> Signed-off-by: Andre Przywara >>> --- >>> tools/testing/selftests/vm/userfaultfd.c | 13 - >>> 1 file changed, 12 insertions(+), 1 deletion(-) >>> >>> diff --git a/tools/testing/selftests/vm/userfaultfd.c >>> b/tools/testing/selftests/vm/userfaultfd.c >>> index 2c7cca6..63be27f 100644 >>> --- a/tools/testing/selftests/vm/userfaultfd.c >>> +++ b/tools/testing/selftests/vm/userfaultfd.c >>> @@ -65,16 +65,27 @@ >>> #include >>> #include >>> #include "../../../../include/uapi/linux/userfaultfd.h" >>> +#include >>> >>> +/* ideally the above user header provides that number, but ... */ >>> +#ifndef __NR_userfaultfd >>> #ifdef __x86_64__ >>> #define __NR_userfaultfd 323 >>> #elif defined(__i386__) >>> #define __NR_userfaultfd 374 >>> -#elif defined(__powewrpc__) >>> +#elif defined(__powerpc__) >>> #define __NR_userfaultfd 364 >>> +#elif defined(__ia64__) >>> +#define __NR_userfaultfd 1343 >>> +#elif defined(__arm__) >>> +#define __NR_userfaultfd 388 >>> +#elif defined(__aarch64__) >>> +/* this is from the generic syscall table, used also on other >>> architectures */ >>> +#define __NR_userfaultfd 283 >>> #else >>> #error "missing __NR_userfaultfd definition" >>> #endif >>> +#endif /* !__NR_userfaultfd */ >>> >>> static unsigned long nr_cpus, nr_pages, nr_pages_per_cpu, page_size; >>> >>> >> >> This is not okay. User-space shouldn't be (re)defining/duplicating >> syscall numbers. I can't take this patch. While I agree that this isn't the right approach from a userland point of view, I wonder how this is supposed to work for the next few months? Is everybody required to overwrite their distribution-provided kernel headers just for compiling this test program? > -mm has already been updated to do exactly that. Syscall numbers end > up hardcoded into userland binaries/libs somewhere, so it's not a > bugfix but certainly it's a nice cleanup to remove the whole #ifdef block. > > Andre, could you see if linux-next (which includes -mm) works for you > by just running "cd tools/testing/selftests/vm/ && make"? If there's > any further change required could you diff it against linux-next? This doesn't compile now for me, because it looks into /usr/include/asm/unistd.h, which I keep to the distribution copy of it. Also linux/userfaultfd.h is missing, because it's brand new. If that tool lives in the kernel repo, it should be able to either use the uapi headers directly or hardcode the syscall numbers - strictly it's not a sane userland program anymore, but for that kind of tools I deem it's totally acceptable. I think this is one rationale for keeping it inside the linux.git repo. Obviously you were facing the same problem in the beginning (looking at the original code), so I was just extending the original solution to cover more architectures and prepare for the time when those symbols start to appear in distributions. I guess the right solution would be to hack the Makefile to set the include path to the kernel's copy of include/uapi, though I am not sure this works cleanly for different architectures and separate build directories. I will give this a try ... Cheers, Andre. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 2/2] selftests/userfaultfd: improve syscall number definition
On Tue, 2015-09-22 at 18:15 +0100, Andre Przywara wrote: > On 22/09/15 15:06, Andrea Arcangeli wrote: > > Andre, could you see if linux-next (which includes -mm) works for you > > by just running "cd tools/testing/selftests/vm/ && make"? If there's > > any further change required could you diff it against linux-next? > > This doesn't compile now for me, because it looks into > /usr/include/asm/unistd.h, which I keep to the distribution copy of it. > Also linux/userfaultfd.h is missing, because it's brand new. ... > I guess the right solution would be to hack the Makefile to set the > include path to the kernel's copy of include/uapi, though I am not sure > this works cleanly for different architectures and separate build > directories. I will give this a try ... Not that's not the right solution. The right solution is to export the kernel headers, the Makefile will pick them up (at least in linux-next): $ cd linux $ make headers_install $ ls usr/include/ asm/ asm-generic/ drm/ linux/ misc/ mtd/ rdma/ scsi/ sound/ uapi/ video/ xen/ $ make -C tools/testing/selftests TARGETS=vm ... $ ls tools/testing/selftests/vm/userfaultfd tools/testing/selftests/vm/userfaultfd* cheers -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 2/2] selftests/userfaultfd: improve syscall number definition
Hi Michael, On 23/09/15 10:55, Michael Ellerman wrote: > On Tue, 2015-09-22 at 18:15 +0100, Andre Przywara wrote: >> On 22/09/15 15:06, Andrea Arcangeli wrote: >>> Andre, could you see if linux-next (which includes -mm) works for you >>> by just running "cd tools/testing/selftests/vm/ && make"? If there's >>> any further change required could you diff it against linux-next? >> >> This doesn't compile now for me, because it looks into >> /usr/include/asm/unistd.h, which I keep to the distribution copy of it. >> Also linux/userfaultfd.h is missing, because it's brand new. > ... >> I guess the right solution would be to hack the Makefile to set the >> include path to the kernel's copy of include/uapi, though I am not sure >> this works cleanly for different architectures and separate build >> directories. I will give this a try ... > > Not that's not the right solution. > > The right solution is to export the kernel headers, the Makefile will pick > them > up (at least in linux-next): Actually that was I was hoping for, I just missed the possibility of headers_install to put the files back into the kernel tree (I usually use it with INSTALL_HDR_PATH for packaging). > > $ cd linux > $ make headers_install > $ ls usr/include/ > asm/ asm-generic/ drm/ linux/ misc/ mtd/ rdma/ scsi/ sound/ uapi/ > video/ xen/ > $ make -C tools/testing/selftests TARGETS=vm > ... > $ ls tools/testing/selftests/vm/userfaultfd > tools/testing/selftests/vm/userfaultfd* Yes, that works. Now I have just to figure out how to arrange this with out-of-tree build directories. Cheers, Andre. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 2/2] selftests/userfaultfd: improve syscall number definition
On Wed, 2015-09-23 at 14:11 +0100, Andre Przywara wrote: > Hi Michael, > > On 23/09/15 10:55, Michael Ellerman wrote: > > On Tue, 2015-09-22 at 18:15 +0100, Andre Przywara wrote: > >> On 22/09/15 15:06, Andrea Arcangeli wrote: > >>> Andre, could you see if linux-next (which includes -mm) works for you > >>> by just running "cd tools/testing/selftests/vm/ && make"? If there's > >>> any further change required could you diff it against linux-next? > >> > >> This doesn't compile now for me, because it looks into > >> /usr/include/asm/unistd.h, which I keep to the distribution copy of it. > >> Also linux/userfaultfd.h is missing, because it's brand new. > > ... > >> I guess the right solution would be to hack the Makefile to set the > >> include path to the kernel's copy of include/uapi, though I am not sure > >> this works cleanly for different architectures and separate build > >> directories. I will give this a try ... > > > > Not that's not the right solution. > > > > The right solution is to export the kernel headers, the Makefile will pick > > them > > up (at least in linux-next): > > Actually that was I was hoping for, I just missed the possibility of > headers_install to put the files back into the kernel tree (I usually > use it with INSTALL_HDR_PATH for packaging). OK great. It does seem that folks are struggling to work out how to do this, so maybe we can come up with a way to have it automated. > > $ cd linux > > $ make headers_install > > $ ls usr/include/ > > asm/ asm-generic/ drm/ linux/ misc/ mtd/ rdma/ scsi/ sound/ > > uapi/ video/ xen/ > > $ make -C tools/testing/selftests TARGETS=vm > > ... > > $ ls tools/testing/selftests/vm/userfaultfd > > tools/testing/selftests/vm/userfaultfd* > > Yes, that works. Now I have just to figure out how to arrange this with > out-of-tree build directories. Right, I think it doesn't work at the moment. The makefiles that look for the kernel headers use ../../../../usr/include, which probably isn't what you want for an out of tree build. Maybe we should do something like the below. It allows you to do: $ make O=~/work/build/ headers_install $ ls ~/work/build/usr/include/ asm/ asm-generic/ drm/ linux/ misc/ mtd/ rdma/ scsi/ sound/ uapi/ video/ xen/ $ ls usr/include ls: cannot access usr/include: No such file or directory $ make -C tools/testing/selftests KERNEL_HEADERS=~/work/build/usr/include/ TARGEST=vm $ ls tools/testing/selftests/vm/userfaultfd tools/testing/selftests/vm/userfaultfd* cheers diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index 8922c2155a47..617a76be3889 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -41,6 +41,9 @@ override LDFLAGS = override MAKEFLAGS = endif +KERNEL_HEADERS ?= $(abspath ../../../usr/include) +export KERNEL_HEADERS + all: for TARGET in $(TARGETS); do \ make -C $$TARGET; \ diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile index e4bb1de1d526..4f45b9c8dd75 100644 --- a/tools/testing/selftests/vm/Makefile +++ b/tools/testing/selftests/vm/Makefile @@ -1,6 +1,6 @@ # Makefile for vm selftests -CFLAGS = -Wall -I ../../../../usr/include $(EXTRA_CFLAGS) +CFLAGS = -Wall -I $(KERNEL_HEADERS) $(EXTRA_CFLAGS) BINARIES = compaction_test BINARIES += hugepage-mmap BINARIES += hugepage-shm @@ -14,12 +14,9 @@ BINARIES += userfaultfd all: $(BINARIES) %: %.c $(CC) $(CFLAGS) -o $@ $^ -lrt -userfaultfd: userfaultfd.c ../../../../usr/include/linux/kernel.h +userfaultfd: userfaultfd.c $(KERNEL_HEADERS)/linux/kernel.h $(CC) $(CFLAGS) -O2 -o $@ $< -lpthread -../../../../usr/include/linux/kernel.h: - make -C ../../../.. headers_install - TEST_PROGS := run_vmtests TEST_FILES := $(BINARIES) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/