ARM: 9304/1: add prototype for function called only from asm

When building with 'make W=1', the compiler warns about any function
definition that does not come with a prototype in a header, to ensure
it matches what the caller expects.

This includes functions that are only ever caller from assembly
code and don't technically need a declaration:

arch/arm/kernel/ftrace.c:227:6: error: no previous prototype for 'prepare_ftrace_return'
arch/arm/kernel/ptrace.c:850:16: error: no previous prototype for 'syscall_trace_enter'
arch/arm/kernel/ptrace.c:878:17: error: no previous prototype for 'syscall_trace_exit'
arch/arm/kernel/signal.c:601:1: error: no previous prototype for 'do_work_pending'
arch/arm/kernel/signal.c:672:17: error: no previous prototype for 'do_rseq_syscall'
arch/arm/kernel/suspend.c:75:6: error: no previous prototype for '__cpu_suspend_save'
arch/arm/kernel/traps.c:451:17: error: no previous prototype for 'do_undefinstr'
arch/arm/kernel/traps.c:516:39: error: no previous prototype for 'handle_fiq_as_nmi'
arch/arm/kernel/traps.c:535:17: error: no previous prototype for 'bad_mode'
arch/arm/kernel/traps.c:608:16: error: no previous prototype for 'arm_syscall'
arch/arm/kernel/traps.c:734:1: error: no previous prototype for 'baddataabort'
arch/arm/kernel/traps.c:774:17: error: no previous prototype for '__div0'
arch/arm/kernel/traps.c:97:6: error: no previous prototype for 'dump_backtrace_stm'
arch/arm/kernel/unwind.c:40:6: error: no previous prototype for '__aeabi_unwind_cpp_pr0'
arch/arm/kernel/unwind.c:45:6: error: no previous prototype for '__aeabi_unwind_cpp_pr1'
arch/arm/kernel/unwind.c:50:6: error: no previous prototype for '__aeabi_unwind_cpp_pr2'
arch/arm/mm/fault.c:554:1: error: no previous prototype for 'do_DataAbort'
arch/arm/mm/fault.c:584:1: error: no previous prototype for 'do_PrefetchAbort'
arch/arm/mm/proc-v7-bugs.c:280:6: error: no previous prototype for 'cpu_v7_ca8_ibe'
arch/arm/mm/proc-v7-bugs.c:293:6: error: no previous prototype for 'cpu_v7_bugs_init'
arch/arm/vdso/vgettimeofday.c:36:6: error: no previous prototype for '__aeabi_unwind_cpp_pr0'
arch/arm/vdso/vgettimeofday.c:40:6: error: no previous prototype for '__aeabi_unwind_cpp_pr1'
arch/arm/vdso/vgettimeofday.c:44:6: error: no previous prototype for '__aeabi_unwind_cpp_pr2'
arch/arm/vfp/vfpmodule.c:323:6: error: no previous prototype for 'VFP_bounce'

Add the prototypes anyway, to allow enabling this warning by default in
the future.

Reviewed-by: Kees Cook <[e-mail]>
Signed-off-by: Arnd Bergmann <[e-mail]>
Signed-off-by: Russell King (Oracle) <[e-mail]>

arch/arm/include/asm/ftrace.h

···
 	return !strcasecmp(sym, name);
 }
 
+void prepare_ftrace_return(unsigned long *parent, unsigned long self,
+			   unsigned long frame_pointer,
+			   unsigned long stack_pointer);
+
 #endif /* ifndef __ASSEMBLY__ */
 
 #endif /* _ASM_ARM_FTRACE */

arch/arm/include/asm/ptrace.h

···
 	return cpsr;
 }
 
+int syscall_trace_enter(struct pt_regs *regs);
+void syscall_trace_exit(struct pt_regs *regs);
+
 #endif /* __ASSEMBLY__ */
 #endif

arch/arm/include/asm/signal.h

···
 #define __ARCH_HAS_SA_RESTORER
 
 #include <asm/sigcontext.h>
+
+void do_rseq_syscall(struct pt_regs *regs);
+int do_work_pending(struct pt_regs *regs, unsigned int thread_flags,
+		    int syscall);
+
 #endif

arch/arm/include/asm/spectre.h

···
 
 int spectre_bhb_update_vectors(unsigned int method);
 
+void cpu_v7_ca8_ibe(void);
+void cpu_v7_ca15_ibe(void);
+void cpu_v7_bugs_init(void);
+
 #endif

arch/arm/include/asm/suspend.h

···
 extern void cpu_resume_no_hyp(void);
 extern void cpu_resume_arm(void);
 extern int cpu_suspend(unsigned long, int (*)(unsigned long));
+extern void __cpu_suspend_save(u32 *ptr, u32 ptrsz, u32 sp, u32 *save_ptr);
 
 #endif

arch/arm/include/asm/traps.h

···
 
 extern void *vectors_page;
 
+asmlinkage void dump_backtrace_stm(u32 *stack, u32 instruction, const char *loglvl);
+asmlinkage void do_undefinstr(struct pt_regs *regs);
+asmlinkage void handle_fiq_as_nmi(struct pt_regs *regs);
+asmlinkage void bad_mode(struct pt_regs *regs, int reason);
+asmlinkage int arm_syscall(int no, struct pt_regs *regs);
+asmlinkage void baddataabort(int code, unsigned long instr, struct pt_regs *regs);
+asmlinkage void __div0(void);
+asmlinkage void handle_bad_stack(struct pt_regs *regs);
+
 #endif

arch/arm/include/asm/unwind.h

···
 extern void unwind_backtrace(struct pt_regs *regs, struct task_struct *tsk,
 			     const char *loglvl);
 
+void __aeabi_unwind_cpp_pr0(void);
+void __aeabi_unwind_cpp_pr1(void);
+void __aeabi_unwind_cpp_pr2(void);
+
 #endif	/* !__ASSEMBLY__ */
 
 #ifdef CONFIG_ARM_UNWIND

arch/arm/include/asm/vfp.h

···
 
 #ifndef __ASSEMBLY__
 void vfp_disable(void);
+void VFP_bounce(u32 trigger, u32 fpexc, struct pt_regs *regs);
 #endif
 
 #endif /* __ASM_VFP_H */

arch/arm/mm/fault.h

···
 
 void do_bad_area(unsigned long addr, unsigned int fsr, struct pt_regs *regs);
 void early_abt_enable(void);
+asmlinkage void do_DataAbort(unsigned long addr, unsigned int fsr,
+			     struct pt_regs *regs);
+asmlinkage void do_PrefetchAbort(unsigned long addr, unsigned int ifsr,
+				 struct pt_regs *regs);
 
 #endif	/* __ARCH_ARM_FAULT_H */