| Message ID | 1242203541-12959-1-git-send-email-markmc@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wednesday 13 May 2009 08:32:21 Mark McLoughlin wrote: > Currently we only include $(KERNELDIR)/include in CFLAGS, > but we also have $(KERNELDIR)/arch/$(arch)/include or else > we'll get mis-matched headers. > I think this is fundamentally wrong. User files should never directly access kernel headers, because they are postprocessed in various ways in order to get files that are valid in user space, e.g. __user annotations are removed. The three possible sources for kernel headers are: /usr/include - system provided headers, may be older than the running kernel /lib/modules/$(uname -r)/build/usr/include - user space headers for the currently running kernel $(KERNELDIR)/usr/include - user space headers from a configured kernel tree after 'make headers_install' Arnd <>< -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, 2009-05-13 at 21:57 +0000, Arnd Bergmann wrote: > On Wednesday 13 May 2009 08:32:21 Mark McLoughlin wrote: > > Currently we only include $(KERNELDIR)/include in CFLAGS, > > but we also have $(KERNELDIR)/arch/$(arch)/include or else > > we'll get mis-matched headers. > > > > I think this is fundamentally wrong. User files should never directly > access kernel headers, Just to be more clear on the use case for this patch - it's needed to allow building kvmtrace against the copy of kvm kernel headers carried in the qemu-kvm-0.10.4 release tarball. > because they are postprocessed in various > ways in order to get files that are valid in user space, e.g. __user > annotations are removed. > > The three possible sources for kernel headers are: > > /usr/include > - system provided headers, may be older than the running kernel > /lib/modules/$(uname -r)/build/usr/include > - user space headers for the currently running kernel > $(KERNELDIR)/usr/include > - user space headers from a configured kernel tree after 'make headers_install' Cheers, Mark. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Arnd Bergmann wrote: > On Wednesday 13 May 2009 08:32:21 Mark McLoughlin wrote: > >> Currently we only include $(KERNELDIR)/include in CFLAGS, >> but we also have $(KERNELDIR)/arch/$(arch)/include or else >> we'll get mis-matched headers. >> >> > > I think this is fundamentally wrong. User files should never directly > access kernel headers, because they are postprocessed in various > ways in order to get files that are valid in user space, e.g. __user > annotations are removed. > There aren't the real kernel headers, just cheap copies carried in qemu-kvm.git which have been appropriately postprocessed. We do this since the kvm external module can run on a much older kernel, so there is no natural place to find it headers. > The three possible sources for kernel headers are: > > /usr/include > - system provided headers, may be older than the running kernel > /lib/modules/$(uname -r)/build/usr/include > - user space headers for the currently running kernel > $(KERNELDIR)/usr/include > - user space headers from a configured kernel tree after 'make headers_install' None of these are sufficiently up-to-date.
Mark McLoughlin wrote: > Currently we only include $(KERNELDIR)/include in CFLAGS, > but we also have $(KERNELDIR)/arch/$(arch)/include or else > we'll get mis-matched headers. > > Signed-off-by: Mark McLoughlin <markmc@redhat.com> > --- > kvm/user/config-i386.mak | 1 - > kvm/user/config-ia64.mak | 1 + > kvm/user/config-powerpc.mak | 1 + > kvm/user/config-x86-common.mak | 2 ++ > kvm/user/config-x86_64.mak | 1 - > 5 files changed, 4 insertions(+), 2 deletions(-) > > > diff --git a/kvm/user/config-ia64.mak b/kvm/user/config-ia64.mak > index c4c639e..e8803a0 100644 > --- a/kvm/user/config-ia64.mak > +++ b/kvm/user/config-ia64.mak > @@ -2,6 +2,7 @@ bits = 64 > CFLAGS += -m64 > CFLAGS += -D__ia64__ > CFLAGS += -I $(KERNELDIR)/include > +CFLAGS += -I $(KERNELDIR)/arch/ia64/include > (TEST_DIR)/stringio.flat \ > Can we have arch/$(ARCH)/include in some central place instead? I can't bear the thought of touching this again when we merge ARM. btw, I'd like to see the kvm/user/test stuff ported to load with qemu -kernel instead of the custom bootstrap. We lose the simplicity of kvmctl, but we don't really need it now (kvmctl predates qemu-kvm; it was how we ran virtual machines until we noticed we didn't have a device model).
diff --git a/kvm/user/config-i386.mak b/kvm/user/config-i386.mak index 09175d5..eebb9de 100644 --- a/kvm/user/config-i386.mak +++ b/kvm/user/config-i386.mak @@ -3,7 +3,6 @@ cstart.o = $(TEST_DIR)/cstart.o bits = 32 ldarch = elf32-i386 CFLAGS += -D__i386__ -CFLAGS += -I $(KERNELDIR)/include tests= diff --git a/kvm/user/config-ia64.mak b/kvm/user/config-ia64.mak index c4c639e..e8803a0 100644 --- a/kvm/user/config-ia64.mak +++ b/kvm/user/config-ia64.mak @@ -2,6 +2,7 @@ bits = 64 CFLAGS += -m64 CFLAGS += -D__ia64__ CFLAGS += -I $(KERNELDIR)/include +CFLAGS += -I $(KERNELDIR)/arch/ia64/include all: diff --git a/kvm/user/config-powerpc.mak b/kvm/user/config-powerpc.mak index dd7ef54..589aa61 100644 --- a/kvm/user/config-powerpc.mak +++ b/kvm/user/config-powerpc.mak @@ -1,4 +1,5 @@ CFLAGS += -I $(KERNELDIR)/include +CFLAGS += -I $(KERNELDIR)/arch/powerpc/include CFLAGS += -Wa,-mregnames -I test/lib CFLAGS += -ffreestanding diff --git a/kvm/user/config-x86-common.mak b/kvm/user/config-x86-common.mak index e789fd4..8d8fadf 100644 --- a/kvm/user/config-x86-common.mak +++ b/kvm/user/config-x86-common.mak @@ -12,6 +12,8 @@ cflatobjs += \ $(libcflat): LDFLAGS += -nostdlib $(libcflat): CFLAGS += -ffreestanding -I test/lib +CFLAGS += -I $(KERNELDIR)/include +CFLAGS += -I $(KERNELDIR)/arch/x86/include CFLAGS += -m$(bits) FLATLIBS = test/lib/libcflat.a $(libgcc) diff --git a/kvm/user/config-x86_64.mak b/kvm/user/config-x86_64.mak index b50b540..d88f54c 100644 --- a/kvm/user/config-x86_64.mak +++ b/kvm/user/config-x86_64.mak @@ -3,7 +3,6 @@ cstart.o = $(TEST_DIR)/cstart64.o bits = 64 ldarch = elf64-x86-64 CFLAGS += -D__x86_64__ -CFLAGS += -I $(KERNELDIR)/include tests = $(TEST_DIR)/access.flat $(TEST_DIR)/irq.flat $(TEST_DIR)/sieve.flat \ $(TEST_DIR)/simple.flat $(TEST_DIR)/stringio.flat \
Currently we only include $(KERNELDIR)/include in CFLAGS, but we also have $(KERNELDIR)/arch/$(arch)/include or else we'll get mis-matched headers. Signed-off-by: Mark McLoughlin <markmc@redhat.com> --- kvm/user/config-i386.mak | 1 - kvm/user/config-ia64.mak | 1 + kvm/user/config-powerpc.mak | 1 + kvm/user/config-x86-common.mak | 2 ++ kvm/user/config-x86_64.mak | 1 - 5 files changed, 4 insertions(+), 2 deletions(-)