x86/arch_prctl: Add do_arch_prctl_common()

Add do_arch_prctl_common() to handle arch_prctls that are not specific to 64
bit mode. Call it from the syscall entry point, but not any of the other
callsites in the kernel, which all want one of the existing 64 bit only
arch_prctls.

Signed-off-by: Kyle Huey <khuey@kylehuey.com>
Cc: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com>
Cc: kvm@vger.kernel.org
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: linux-kselftest@vger.kernel.org
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Robert O'Callahan <robert@ocallahan.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: user-mode-linux-user@lists.sourceforge.net
Cc: David Matlack <dmatlack@google.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: linux-fsdevel@vger.kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>
Link: http://lkml.kernel.org/r/20170320081628.18952-6-khuey@kylehuey.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/x86/include/asm/proto.h b/arch/x86/include/asm/proto.h
index 4e276f6cb1c1fa6ae074c409bca17c5ad1e0d977..8d3964fc5f915c37ec7bf74706446adc8ad2e93b 100644 (file)
--- a/arch/x86/include/asm/proto.h
+++ b/arch/x86/include/asm/proto.h
@@ -31,4 +31,7 @@ void x86_report_nx(void);
 
 extern int reboot_force;
 
+long do_arch_prctl_common(struct task_struct *task, int option,
+                         unsigned long cpuid_enabled);
+
 #endif /* _ASM_X86_PROTO_H */

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 366db7782fc60d0b6cd83f8f4c4b83887377f7c0..b12e95eceb83d76c2fb71cded930dc47be16fe3e 100644 (file)
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -545,3 +545,9 @@ unsigned long get_wchan(struct task_struct *p)
        put_task_stack(p);
        return ret;
 }
+
+long do_arch_prctl_common(struct task_struct *task, int option,
+                         unsigned long cpuid_enabled)
+{
+       return -EINVAL;
+}

diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index e37f764c11cc89da82bc420e71217a748b7790f7..d81b0a60a45ccf3de1b673d7f7a7e825e9ee97e3 100644 (file)
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -626,7 +626,13 @@ long do_arch_prctl_64(struct task_struct *task, int option, unsigned long arg2)
 
 SYSCALL_DEFINE2(arch_prctl, int, option, unsigned long, arg2)
 {
-       return do_arch_prctl_64(current, option, arg2);
+       long ret;
+
+       ret = do_arch_prctl_64(current, option, arg2);
+       if (ret == -EINVAL)
+               ret = do_arch_prctl_common(current, option, arg2);
+
+       return ret;
 }
 
 unsigned long KSTK_ESP(struct task_struct *task)