Hello,
On Fri, 12 Apr 2013 18:28:26 -0500 Nishanth Menon nm@ti.com wrote:
From: Paul Sokolovsky paul.sokolovsky@linaro.org
An ifdef in drm.h expects to be compiled with full-fledged Linux toolchain, but it's common to compile kernel with just bare-metal toolchain which doesn't define __linux__. So, also add __KERNEL__ check.
[nm@ti.com: port forward to 3.9-rc6 and post to dri devel for feedback as RFC] Signed-off-by: Paul Sokolovsky paul.sokolovsky@linaro.org --- Paul, Dri devel list, I picked up this patch from linaro tree: https://git.linaro.org/gitweb?p=people/asac/android/kernel/lt-ti.git%3Ba=pat... Discussion thread: http://lists.linaro.org/pipermail/linaro-dev/2011-June/thread.html#4874 Seems to me as a valid fix even for upstream perhaps?
Yes, IIRC, per the discussion you quote above, I sent this patch for review of our (Linaro's) kernel folks to see if it's ok (the patch is simple, story why it's needed may be not such, though I was positive it's needed). It might be forgotten somehow, thanks for picking it up!
Regards, Nishanth Menon
include/uapi/drm/drm.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h index 8d1e2bb..73a99e4 100644 --- a/include/uapi/drm/drm.h +++ b/include/uapi/drm/drm.h @@ -36,7 +36,7 @@ #ifndef _DRM_H_ #define _DRM_H_ -#if defined(__linux__) +#if defined(__KERNEL__) || defined(__linux__) #include <linux/types.h> #include <asm/ioctl.h>
On Tuesday 16 April 2013 12:48:28 Paul Sokolovsky wrote:
diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h index 8d1e2bb..73a99e4 100644 --- a/include/uapi/drm/drm.h +++ b/include/uapi/drm/drm.h @@ -36,7 +36,7 @@ #ifndef _DRM_H_ #define _DRM_H_ -#if defined(__linux__) +#if defined(__KERNEL__) || defined(__linux__) #include <linux/types.h> #include <asm/ioctl.h>
This is still completely bogus, the __KERNEL__ symbol has no significance here. Either make the compiler define __linux__, or remove this #ifdef completely.
Arnd
On 12:50-20130416, Arnd Bergmann wrote:
On Tuesday 16 April 2013 12:48:28 Paul Sokolovsky wrote:
diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h index 8d1e2bb..73a99e4 100644 --- a/include/uapi/drm/drm.h +++ b/include/uapi/drm/drm.h @@ -36,7 +36,7 @@ #ifndef _DRM_H_ #define _DRM_H_ -#if defined(__linux__) +#if defined(__KERNEL__) || defined(__linux__) #include <linux/types.h> #include <asm/ioctl.h>
This is still completely bogus, the __KERNEL__ symbol has no significance here. Either make the compiler define __linux__, or remove this #ifdef completely.
Searching the v.39-rc7 tag, and greping for _linux_ a few interesting list pops up. (pruned): arch/arc/Makefile:cflags-y += -mA7 -fno-common -pipe -fno-builtin -D__linux__ arch/h8300/Makefile:KBUILD_CFLAGS += -D__linux__ arch/hexagon/Makefile:KBUILD_CFLAGS += -ffixed-$(TIR_NAME) -DTHREADINFO_REG=$(TIR_NAME) -D__linux__ arch/score/Makefile: -D__linux__ -ffunction-sections -ffreestanding arch/xtensa/Makefile:KBUILD_CFLAGS += -ffreestanding -D__linux__ ^^ these architectures seem to bypass the pain entirely by defining __linux__
arch/mips/include/uapi/asm/sgidefs.h:#ifndef __linux__ drivers/gpu/drm/radeon/radeon_cp.c:#ifdef __linux__ {snip} drivers/scsi/aic7xxx/aic7770.c:#ifdef __linux__ drivers/scsi/aic7xxx/aic79xx.h:#ifndef __linux__ {snip} drivers/scsi/aic7xxx/aic79xx_core.c:#ifdef __linux__ {snip} drivers/scsi/aic7xxx/aic79xx_pci.c:#ifdef __linux__ drivers/scsi/aic7xxx/aic7xxx.h:#ifndef __linux__ drivers/scsi/aic7xxx/aic7xxx.h:#ifndef __linux__ drivers/scsi/aic7xxx/aic7xxx_93cx6.c:#ifdef __linux__ drivers/scsi/aic7xxx/aic7xxx_core.c:#ifdef __linux__ {snip} drivers/scsi/aic7xxx/aic7xxx_pci.c:#ifdef __linux__ drivers/scsi/aic7xxx/aicasm/aicasm.h:#ifdef __linux__ drivers/scsi/aic7xxx/aicasm/aicasm_gram.y:#ifdef __linux__ drivers/scsi/aic7xxx/aicasm/aicasm_macro_scan.l:#ifdef __linux__ drivers/scsi/aic7xxx/aicasm/aicasm_scan.l:#ifdef __linux__ drivers/scsi/aic7xxx/aicasm/aicasm_symbol.c:#ifdef __linux__ drivers/scsi/aic7xxx/aicasm/aicasm_symbol.h:#ifdef __linux__ drivers/scsi/dpt/osd_defs.h:#if (defined(__linux__)) drivers/staging/ced1401/machine.h:#if (defined(__linux__) || defined(_linux) || defined(__linux)) && !defined(LINUX) include/acpi/platform/acenv.h:#if defined(_LINUX) || defined(__linux__) include/linux/coda.h:#if defined(__linux__) include/uapi/drm/drm.h:#if defined(__linux__) include/uapi/linux/coda.h:#if defined(__linux__) include/uapi/linux/fuse.h:#ifdef __linux__
And then we have the following as well.. fs/ext4/ext4.h:#if defined(__KERNEL__) || defined(__linux__)
Trying out a few different prebuilt compilers I had around, I see: http://pastebin.com/bTVDLTb1
So, is our approach just to use __linux__ for builds? I am trying to understand rationale behind why #include <linux/types.h> #include <asm/ioctl.h> would want __linux__ and why __KERNEL__ check is un-wanted. Ofcourse, I cant comment about the "One of the BSDs" in else options.. and why we'd like to keep it around in kernel :)
On Tuesday 16 April 2013, Nishanth Menon wrote:
On 12:50-20130416, Arnd Bergmann wrote:
On Tuesday 16 April 2013 12:48:28 Paul Sokolovsky wrote:
diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h index 8d1e2bb..73a99e4 100644 --- a/include/uapi/drm/drm.h +++ b/include/uapi/drm/drm.h @@ -36,7 +36,7 @@ #ifndef _DRM_H_ #define _DRM_H_ -#if defined(__linux__) +#if defined(__KERNEL__) || defined(__linux__) #include <linux/types.h> #include <asm/ioctl.h>
This is still completely bogus, the __KERNEL__ symbol has no significance here. Either make the compiler define __linux__, or remove this #ifdef completely.
Searching the v.39-rc7 tag, and greping for _linux_ a few interesting list pops up. (pruned): arch/arc/Makefile:cflags-y += -mA7 -fno-common -pipe -fno-builtin -D__linux__ arch/h8300/Makefile:KBUILD_CFLAGS += -D__linux__ arch/hexagon/Makefile:KBUILD_CFLAGS += -ffixed-$(TIR_NAME) -DTHREADINFO_REG=$(TIR_NAME) -D__linux__ arch/score/Makefile: -D__linux__ -ffunction-sections -ffreestanding arch/xtensa/Makefile:KBUILD_CFLAGS += -ffreestanding -D__linux__ ^^ these architectures seem to bypass the pain entirely by defining __linux__
Right, that seems like a reasonable approach when the compilers are actually known to be compatible.
arch/mips/include/uapi/asm/sgidefs.h:#ifndef __linux__
On MIPS, they are not. If you are building a Linux kernel with a gcc that was targetted at another ABI, the system call interface may change, so they forbid that here.
drivers/gpu/drm/radeon/radeon_cp.c:#ifdef __linux__ {snip} drivers/scsi/aic7xxx/aic7770.c:#ifdef __linux__ drivers/scsi/aic7xxx/aic79xx.h:#ifndef __linux__ {snip} drivers/scsi/aic7xxx/aic79xx_core.c:#ifdef __linux__ {snip} drivers/scsi/aic7xxx/aic79xx_pci.c:#ifdef __linux__ drivers/scsi/aic7xxx/aic7xxx.h:#ifndef __linux__ drivers/scsi/aic7xxx/aic7xxx.h:#ifndef __linux__ drivers/scsi/aic7xxx/aic7xxx_93cx6.c:#ifdef __linux__ drivers/scsi/aic7xxx/aic7xxx_core.c:#ifdef __linux__ {snip} drivers/scsi/aic7xxx/aic7xxx_pci.c:#ifdef __linux__ drivers/scsi/aic7xxx/aicasm/aicasm.h:#ifdef __linux__ drivers/scsi/aic7xxx/aicasm/aicasm_macro_scan.l:#ifdef __linux__ drivers/scsi/aic7xxx/aicasm/aicasm_scan.l:#ifdef __linux__ drivers/scsi/aic7xxx/aicasm/aicasm_symbol.c:#ifdef __linux__ drivers/scsi/aic7xxx/aicasm/aicasm_symbol.h:#ifdef __linux__ drivers/scsi/dpt/osd_defs.h:#if (defined(__linux__)) drivers/staging/ced1401/machine.h:#if (defined(__linux__) || defined(_linux) || defined(__linux)) && !defined(LINUX)
These are all drivers that are shared with another OS, or used to be. In most of them, we can probably just remove the #else path, since I don't think they are getting synchronized any more.
include/acpi/platform/acenv.h:#if defined(_LINUX) || defined(__linux__)
The acpi header files are maintained outside of Linux and are kept OS-independent.
include/linux/coda.h:#if defined(__linux__) include/uapi/drm/drm.h:#if defined(__linux__) include/uapi/linux/coda.h:#if defined(__linux__) include/uapi/linux/fuse.h:#ifdef __linux__
In case of coda, we should not need to care any more, that header just got broken by the uapi-split for other operating systems.
The drm.h and fuse.h header files are in theory still kept OS-agnostic and are actively maintained.
And then we have the following as well.. fs/ext4/ext4.h:#if defined(__KERNEL__) || defined(__linux__)
This seems to have been copied from the ext2 utils. The ext2/ext3 versions of this file don't have support for other operating systems.
Trying out a few different prebuilt compilers I had around, I see: http://pastebin.com/bTVDLTb1
So, is our approach just to use __linux__ for builds? I am trying to understand rationale behind why #include <linux/types.h> #include <asm/ioctl.h> would want __linux__ and why __KERNEL__ check is un-wanted. Ofcourse, I cant comment about the "One of the BSDs" in else options.. and why we'd like to keep it around in kernel :)
We might be in a similar situation on ARM that we are in on MIPS. For instance, there are some compilers that are targetting (old) Android that have a slightly different ABI, and building a kernel with those results in a system call ABI that is incompatible with user space built with a standard compiler. The safest approach is probably to bail out early if __linux__ is not set, and force anyone that wants to use a strange compiler to set the macro manually.
Arnd
On Wed, Apr 17, 2013 at 6:43 AM, Arnd Bergmann arnd@arndb.de wrote:
drivers/scsi/aic7xxx/aicasm/aicasm_symbol.c:#ifdef __linux__ drivers/scsi/aic7xxx/aicasm/aicasm_symbol.h:#ifdef __linux__ drivers/scsi/dpt/osd_defs.h:#if (defined(__linux__)) drivers/staging/ced1401/machine.h:#if (defined(__linux__) || defined(_linux) || defined(__linux)) && !defined(LINUX)
These are all drivers that are shared with another OS, or used to be. In most of them, we can probably just remove the #else path, since I don't think they are getting synchronized any more.
note that DRM gets periodically ported to the *BSD's, so possibly the same applies here..
BR, -R
On Tue, 2013-04-16 at 12:50 +0200, Arnd Bergmann wrote:
On Tuesday 16 April 2013 12:48:28 Paul Sokolovsky wrote:
diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h index 8d1e2bb..73a99e4 100644 --- a/include/uapi/drm/drm.h +++ b/include/uapi/drm/drm.h @@ -36,7 +36,7 @@ #ifndef _DRM_H_ #define _DRM_H_ -#if defined(__linux__) +#if defined(__KERNEL__) || defined(__linux__) #include <linux/types.h> #include <asm/ioctl.h>
This is still completely bogus, the __KERNEL__ symbol has no significance here. Either make the compiler define __linux__, or remove this #ifdef completely.
I don't have the full background here but thought I would point out that a similar issue seems to have just cropped up with fuse.h ... http://lkml.org/lkml/2013/4/15/487
-
Arnd Bergmann -
Jon Medhurst (Tixy) -
Nishanth Menon -
Paul Sokolovsky -
Rob Clark