[PATCH] x86/entry: Fix SYS_NI() build failure

From: Ingo Molnar <mingo@kernel.org>
To: Brian Gerst <brgerst@gmail.com>
Cc: linux-kernel@vger.kernel.org, x86@kernel.org,
	Thomas Gleixner <tglx@linutronix.de>,
	Borislav Petkov <bp@alien8.de>, "H . Peter Anvin" <hpa@zytor.com>,
	Andy Lutomirski <luto@kernel.org>,
	Dominik Brodowski <linux@dominikbrodowski.net>
Subject: [PATCH] x86/entry: Fix SYS_NI() build failure
Date: Mon, 23 Mar 2020 09:11:14 +0100	[thread overview]
Message-ID: <20200323081114.GA10796@gmail.com> (raw)
In-Reply-To: <20200313195144.164260-5-brgerst@gmail.com>


* Brian Gerst <brgerst@gmail.com> wrote:

> Pull the common code out from the SYS_NI macros into a new __SYS_NI macro.
> Also conditionalize the X64 version in preparation for enabling syscall
> wrappers on 32-bit native kernels.
>
> Signed-off-by: Brian Gerst <brgerst@gmail.com>
> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
> Reviewed-by: Andy Lutomirski <luto@kernel.org>

>  #define COMPAT_SYS_NI(name)						\
> -	SYSCALL_ALIAS(__ia32_compat_sys_##name, sys_ni_posix_timers);	\
> -	SYSCALL_ALIAS(__x32_compat_sys_##name, sys_ni_posix_timers)
> +	__IA32_COMPAT_SYS_NI(name)					\
> +	__X32_COMPAT_SYS_NI(name)
>  
>  #endif /* CONFIG_COMPAT */
>  
> @@ -231,9 +245,9 @@ struct pt_regs;
>  	__X64_COND_SYSCALL(name)					\
>  	__IA32_COND_SYSCALL(name)
>  
> -#ifndef SYS_NI
> -#define SYS_NI(name) SYSCALL_ALIAS(__x64_sys_##name, sys_ni_posix_timers);
> -#endif
> +#define SYS_NI(name)							\
> +	__X64_SYS_NI(name)						\
> +	__IA32_SYS_NI(name)

This breaks the x86-64 build on !CONFIG_POSIX_TIMERS (and probably also 
with some x32 build variants), because of a missing ';' between 
__X64_SYS_NI() and __IA32_SYS_NI().

I suspect testing didn't catch this because SYS_NI() is rarely used in 
our x86-64 Kconfig space.

Very lightly tested fix attached.

I didn't see the COND_SYSCALL_COMPAT() build failure, but seems to have a 
similar bug.

Thanks,

	Ingo

Signed-off-by: Ingo Molnar <mingo@kernel.org>

---
 arch/x86/include/asm/syscall_wrapper.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/syscall_wrapper.h b/arch/x86/include/asm/syscall_wrapper.h
index e10efa1454bc..8929419b9783 100644
--- a/arch/x86/include/asm/syscall_wrapper.h
+++ b/arch/x86/include/asm/syscall_wrapper.h
@@ -214,12 +214,12 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs);
  * COND_SYSCALL_COMPAT in kernel/sys_ni.c and COMPAT_SYS_NI in
  * kernel/time/posix-stubs.c to cover this case as well.
  */
-#define COND_SYSCALL_COMPAT(name) 					\
-	__IA32_COMPAT_COND_SYSCALL(name)				\
+#define COND_SYSCALL_COMPAT(name)					\
+	__IA32_COMPAT_COND_SYSCALL(name);				\
 	__X32_COMPAT_COND_SYSCALL(name)
 
 #define COMPAT_SYS_NI(name)						\
-	__IA32_COMPAT_SYS_NI(name)					\
+	__IA32_COMPAT_SYS_NI(name);					\
 	__X32_COMPAT_SYS_NI(name)
 
 #endif /* CONFIG_COMPAT */
@@ -257,7 +257,7 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs);
 	__IA32_COND_SYSCALL(name)
 
 #define SYS_NI(name)							\
-	__X64_SYS_NI(name)						\
+	__X64_SYS_NI(name);						\
 	__IA32_SYS_NI(name)
 
 
