[v2] arm64: add guard macros of unistd.h to prevent double inclusion

Commit Message

Yang Yingliang Sept. 11, 2014, 9:21 a.m. UTC

From: Yang Yingliang <[e-mail]>

Add guard macros for uapi/asm/unistd.h, asm/unistd.h and
asm/unistd32.h.

Signed-off-by: Yang Yingliang <[e-mail]>
---
 arch/arm64/include/asm/unistd.h      | 5 +++++
 arch/arm64/include/asm/unistd32.h    | 4 ++++
 arch/arm64/include/uapi/asm/unistd.h | 5 +++++
 3 files changed, 14 insertions(+)

Comments

Will Deacon Sept. 11, 2014, 3:02 p.m. UTC | #1

On Thu, Sep 11, 2014 at 10:21:18AM +0100, Yang Yingliang wrote:
> From: Yang Yingliang <[e-mail]>
> 
> Add guard macros for uapi/asm/unistd.h, asm/unistd.h and
> asm/unistd32.h.

Hmm, so I applied this and now my machine panics when we hit userspace. I
think the issue is that we no longer generate our syscall table in
arch/arm64/kernel/sys.c, because unistd.h is already included via
linux/syscalls.h but without the __SYSCALL definition.

So, a couple of questions:

  (1) Is the lack of header guards actually causing you a problem?
  (2) How did you test this?

I've dropped the patch.

Will

Yang Yingliang Sept. 12, 2014, 9:03 a.m. UTC | #2

On 2014/9/11 23:02, Will Deacon wrote:
> On Thu, Sep 11, 2014 at 10:21:18AM +0100, Yang Yingliang wrote:
>> From: Yang Yingliang <[e-mail]>
>>
>> Add guard macros for uapi/asm/unistd.h, asm/unistd.h and
>> asm/unistd32.h.
> 
> Hmm, so I applied this and now my machine panics when we hit userspace. I
> think the issue is that we no longer generate our syscall table in
> arch/arm64/kernel/sys.c, because unistd.h is already included via
> linux/syscalls.h but without the __SYSCALL definition.
> 
> So, a couple of questions:
> 
>   (1) Is the lack of header guards actually causing you a problem?
>   (2) How did you test this?
> 
> I've dropped the patch.
> 
> Will
> 
> 
Oh, my bad, sorry for that.

I found asm/unistd.h have no guard macro when I was migrate a userspace
program from x86_64 to arm64. The program uses the macro _ASM_X86_UNISTD_64_H,
but arm64 does not have this(arm has __ASM_ARM_UNISTD_H). So I tried to add
the guard macro.

Regards,
Yang

Patch

diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h
index 6d2bf41..21a7dec 100644
--- a/arch/arm64/include/asm/unistd.h
+++ b/arch/arm64/include/asm/unistd.h
@@ -13,6 +13,9 @@ 
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
+#ifndef __ASM_ARM64_UNISTD_H
+#define __ASM_ARM64_UNISTD_H
+
 #ifdef CONFIG_COMPAT
 #define __ARCH_WANT_COMPAT_SYS_GETDENTS64
 #define __ARCH_WANT_COMPAT_STAT64
@@ -48,3 +51,5 @@ 
 #include <uapi/asm/unistd.h>
 
 #define NR_syscalls (__NR_syscalls)
+
+#endif /* __ASM_ARM64_UNISTD_H */
diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h
index da1f06b..8f5e78e 100644
--- a/arch/arm64/include/asm/unistd32.h
+++ b/arch/arm64/include/asm/unistd32.h
@@ -16,6 +16,8 @@ 
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
+#ifndef __ASM_ARM64_UNISTD32_H
+#define __ASM_ARM64_UNISTD32_H
 
 #ifndef __SYSCALL
 #define __SYSCALL(x, y)
@@ -792,3 +794,5 @@  __SYSCALL(__NR_renameat2, sys_renameat2)
 __SYSCALL(__NR_getrandom, sys_getrandom)
 #define __NR_memfd_create 385
 __SYSCALL(__NR_memfd_create, sys_memfd_create)
+
+#endif /* __ASM_ARM64_UNISTD32_H */
diff --git a/arch/arm64/include/uapi/asm/unistd.h b/arch/arm64/include/uapi/asm/unistd.h
index 1caadc2..ab72cac 100644
--- a/arch/arm64/include/uapi/asm/unistd.h
+++ b/arch/arm64/include/uapi/asm/unistd.h
@@ -13,4 +13,9 @@ 
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
+#ifndef _UAPI__ASM_ARM64_UNISTD_H
+#define _UAPI__ASM_ARM64_UNISTD_H
+
 #include <asm-generic/unistd.h>
+
+#endif /* _UAPI__ASM_ARM64_UNISTD_H */