syscall_get_arch: remove useless function arguments

Every caller of syscall_get_arch() uses current for the task and no
implementors of the function need args.  So just get rid of both of
those things.  Admittedly, since these are inline functions we aren't
wasting stack space, but it just makes the prototypes better.
Signed-off-by: NEric Paris <eparis@redhat.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-mips@linux-mips.org
Cc: linux390@de.ibm.com
Cc: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linux-arch@vger.kernel.org

arch/arm/include/asm/syscall.h

@@ -103,8 +103,7 @@ static inline void syscall_set_arguments(struct task_struct *task,
 	memcpy(&regs->ARM_r0 + i, args, n * sizeof(args[0]));
 }
 
-static inline int syscall_get_arch(struct task_struct *task,
-				   struct pt_regs *regs)
+static inline int syscall_get_arch(void)
 {
 	/* ARM tasks don't change audit architectures on the fly. */
 	return AUDIT_ARCH_ARM;

arch/mips/include/asm/syscall.h

@@ -101,7 +101,7 @@ extern const unsigned long sys_call_table[];
 extern const unsigned long sys32_call_table[];
 extern const unsigned long sysn32_call_table[];
 
-static inline int __syscall_get_arch(void)
+static inline int syscall_get_arch(void)
 {
 	int arch = EM_MIPS;
 #ifdef CONFIG_64BIT

arch/mips/kernel/ptrace.c

@@ -671,7 +671,7 @@ asmlinkage void syscall_trace_enter(struct pt_regs *regs)
 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 		trace_sys_enter(regs, regs->regs[2]);
 
-	audit_syscall_entry(__syscall_get_arch(),
+	audit_syscall_entry(syscall_get_arch(),
 			    regs->regs[2],
 			    regs->regs[4], regs->regs[5],
 			    regs->regs[6], regs->regs[7]);

arch/s390/include/asm/syscall.h

@@ -89,11 +89,10 @@ static inline void syscall_set_arguments(struct task_struct *task,
 		regs->orig_gpr2 = args[0];
 }
 
-static inline int syscall_get_arch(struct task_struct *task,
-				   struct pt_regs *regs)
+static inline int syscall_get_arch(void)
 {
 #ifdef CONFIG_COMPAT
-	if (test_tsk_thread_flag(task, TIF_31BIT))
+	if (test_tsk_thread_flag(current, TIF_31BIT))
 		return AUDIT_ARCH_S390;
 #endif
 	return sizeof(long) == 8 ? AUDIT_ARCH_S390X : AUDIT_ARCH_S390;

arch/x86/include/asm/syscall.h

@@ -91,8 +91,7 @@ static inline void syscall_set_arguments(struct task_struct *task,
 	memcpy(&regs->bx + i, args, n * sizeof(args[0]));
 }
 
-static inline int syscall_get_arch(struct task_struct *task,
-				   struct pt_regs *regs)
+static inline int syscall_get_arch(void)
 {
 	return AUDIT_ARCH_I386;
 }
@@ -221,8 +220,7 @@ static inline void syscall_set_arguments(struct task_struct *task,
 		}
 }
 
-static inline int syscall_get_arch(struct task_struct *task,
-				   struct pt_regs *regs)
+static inline int syscall_get_arch(void)
 {
 #ifdef CONFIG_IA32_EMULATION
 	/*
@@ -234,7 +232,7 @@ static inline int syscall_get_arch(struct task_struct *task,
 	 *
 	 * x32 tasks should be considered AUDIT_ARCH_X86_64.
 	 */
-	if (task_thread_info(task)->status & TS_COMPAT)
+	if (task_thread_info(current)->status & TS_COMPAT)
 		return AUDIT_ARCH_I386;
 #endif
 	/* Both x32 and x86_64 are considered "64-bit". */

include/asm-generic/syscall.h

@@ -144,8 +144,6 @@ void syscall_set_arguments(struct task_struct *task, struct pt_regs *regs,
 
 /**
  * syscall_get_arch - return the AUDIT_ARCH for the current system call
- * @task:	task of interest, must be in system call entry tracing
- * @regs:	task_pt_regs() of @task
  *
  * Returns the AUDIT_ARCH_* based on the system call convention in use.
  *
@@ -155,5 +153,5 @@ void syscall_set_arguments(struct task_struct *task, struct pt_regs *regs,
  * Architectures which permit CONFIG_HAVE_ARCH_SECCOMP_FILTER must
  * provide an implementation of this.
  */
-int syscall_get_arch(struct task_struct *task, struct pt_regs *regs);
+int syscall_get_arch(void);
 #endif	/* _ASM_SYSCALL_H */

kernel/seccomp.c

@@ -95,7 +95,7 @@ u32 seccomp_bpf_load(int off)
 	if (off == BPF_DATA(nr))
 		return syscall_get_nr(current, regs);
 	if (off == BPF_DATA(arch))
-		return syscall_get_arch(current, regs);
+		return syscall_get_arch();
 	if (off >= BPF_DATA(args[0]) && off < BPF_DATA(args[6])) {
 		unsigned long value;
 		int arg = (off - BPF_DATA(args[0])) / sizeof(u64);
@@ -351,7 +351,7 @@ static void seccomp_send_sigsys(int syscall, int reason)
 	info.si_code = SYS_SECCOMP;
 	info.si_call_addr = (void __user *)KSTK_EIP(current);
 	info.si_errno = reason;
-	info.si_arch = syscall_get_arch(current, task_pt_regs(current));
+	info.si_arch = syscall_get_arch();
 	info.si_syscall = syscall;
 	force_sig_info(SIGSYS, &info, current);
 }