arch/tile: Use <asm-generic/syscalls.h>

With this change we now include <asm-generic/syscalls.h> into the "tile"
version of the header.  To take full advantage of the prototypes there,
we also change our naming convention for "struct pt_regs *" syscalls so
that, e.g., _sys_execve() is the "true" syscall entry, which sets the
appropriate register to point to the pt_regs before calling sys_execve().

While doing this I realized I no longer needed the fork and vfork
entry point stubs, since those functions aren't in the generic
syscall ABI, so I removed them as well.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

arch/tile/kernel/compat.c

@@ -157,6 +157,12 @@ long tile_compat_sys_msgrcv(int msqid,
 /* Pass full 64-bit values through ptrace. */
 #define compat_sys_ptrace tile_compat_sys_ptrace
 
+/* Call the trampolines to manage pt_regs where necessary. */
+#define compat_sys_execve _compat_sys_execve
+#define compat_sys_sigaltstack _compat_sys_sigaltstack
+#define compat_sys_rt_sigreturn _compat_sys_rt_sigreturn
+#define sys_clone _sys_clone
+
 /*
  * Note that we can't include <linux/unistd.h> here since the header
  * guard will defeat us; <asm/unistd.h> checks for __SYSCALL as well.

arch/tile/kernel/compat_signal.c

@@ -256,9 +256,9 @@ int copy_siginfo_from_user32(siginfo_t *to, struct compat_siginfo __user *from)
 	return err;
 }
 
-long _compat_sys_sigaltstack(const struct compat_sigaltstack __user *uss_ptr,
-			     struct compat_sigaltstack __user *uoss_ptr,
-			     struct pt_regs *regs)
+long compat_sys_sigaltstack(const struct compat_sigaltstack __user *uss_ptr,
+			    struct compat_sigaltstack __user *uoss_ptr,
+			    struct pt_regs *regs)
 {
 	stack_t uss, uoss;
 	int ret;
@@ -291,7 +291,7 @@ long _compat_sys_sigaltstack(const struct compat_sigaltstack __user *uss_ptr,
 	return ret;
 }
 
-long _compat_sys_rt_sigreturn(struct pt_regs *regs)
+long compat_sys_rt_sigreturn(struct pt_regs *regs)
 {
 	struct compat_rt_sigframe __user *frame =
 		(struct compat_rt_sigframe __user *) compat_ptr(regs->sp);
@@ -312,7 +312,7 @@ long _compat_sys_rt_sigreturn(struct pt_regs *regs)
 	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0))
 		goto badframe;
 
-	if (_compat_sys_sigaltstack(&frame->uc.uc_stack, NULL, regs) != 0)
+	if (compat_sys_sigaltstack(&frame->uc.uc_stack, NULL, regs) != 0)
 		goto badframe;
 
 	return r0;

arch/tile/kernel/intvec_32.S

@@ -1524,28 +1524,23 @@ STD_ENTRY_LOCAL(bad_intr)
 
 /* Put address of pt_regs in reg and jump. */
 #define PTREGS_SYSCALL(x, reg)                          \
-	STD_ENTRY(x);                                   \
+	STD_ENTRY(_##x);                                \
 	{                                               \
 	 PTREGS_PTR(reg, PTREGS_OFFSET_BASE);           \
-	 j      _##x                                    \
+	 j      x                                       \
 	};                                              \
-	STD_ENDPROC(x)
+	STD_ENDPROC(_##x)
 
 PTREGS_SYSCALL(sys_execve, r3)
 PTREGS_SYSCALL(sys_sigaltstack, r2)
 PTREGS_SYSCALL(sys_rt_sigreturn, r0)
+PTREGS_SYSCALL(sys_cmpxchg_badaddr, r1)
 
-/* Save additional callee-saves to pt_regs, put address in reg and jump. */
-#define PTREGS_SYSCALL_ALL_REGS(x, reg)                 \
-	STD_ENTRY(x);                                   \
-	push_extra_callee_saves reg;                    \
-	j       _##x;                                   \
-	STD_ENDPROC(x)
-
-PTREGS_SYSCALL_ALL_REGS(sys_fork, r0)
-PTREGS_SYSCALL_ALL_REGS(sys_vfork, r0)
-PTREGS_SYSCALL_ALL_REGS(sys_clone, r4)
-PTREGS_SYSCALL_ALL_REGS(sys_cmpxchg_badaddr, r1)
+/* Save additional callee-saves to pt_regs, put address in r4 and jump. */
+STD_ENTRY(_sys_clone)
+	push_extra_callee_saves r4
+	j       sys_clone
+	STD_ENDPROC(_sys_clone)
 
 /*
  * This entrypoint is taken for the cmpxchg and atomic_update fast

arch/tile/kernel/process.c

@@ -528,14 +528,9 @@ struct task_struct *__sched _switch_to(struct task_struct *prev,
 	return __switch_to(prev, next, next_current_ksp0(next));
 }
 
-long _sys_fork(struct pt_regs *regs)
-{
-	return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL);
-}
-
-long _sys_clone(unsigned long clone_flags, unsigned long newsp,
-		void __user *parent_tidptr, void __user *child_tidptr,
-		struct pt_regs *regs)
+SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp,
+		void __user *, parent_tidptr, void __user *, child_tidptr,
+		struct pt_regs *, regs)
 {
 	if (!newsp)
 		newsp = regs->sp;
@@ -543,18 +538,13 @@ long _sys_clone(unsigned long clone_flags, unsigned long newsp,
 		       parent_tidptr, child_tidptr);
 }
 
-long _sys_vfork(struct pt_regs *regs)
-{
-	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp,
-		       regs, 0, NULL, NULL);
-}
-
 /*
  * sys_execve() executes a new program.
  */
-long _sys_execve(const char __user *path,
-		 const char __user *const __user *argv,
-		 const char __user *const __user *envp, struct pt_regs *regs)
+SYSCALL_DEFINE4(execve, const char __user *, path,
+		const char __user *const __user *, argv,
+		const char __user *const __user *, envp,
+		struct pt_regs *, regs)
 {
 	long error;
 	char *filename;
@@ -570,9 +560,10 @@ out:
 }
 
 #ifdef CONFIG_COMPAT
-long _compat_sys_execve(const char __user *path,
-			const compat_uptr_t __user *argv,
-			const compat_uptr_t __user *envp, struct pt_regs *regs)
+long compat_sys_execve(const char __user *path,
+		       const compat_uptr_t __user *argv,
+		       const compat_uptr_t __user *envp,
+		       struct pt_regs *regs)
 {
 	long error;
 	char *filename;

arch/tile/kernel/signal.c

@@ -41,8 +41,8 @@
 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
 
 
-long _sys_sigaltstack(const stack_t __user *uss,
-		      stack_t __user *uoss, struct pt_regs *regs)
+SYSCALL_DEFINE3(sigaltstack, const stack_t __user *, uss,
+		stack_t __user *, uoss, struct pt_regs *, regs)
 {
 	return do_sigaltstack(uss, uoss, regs->sp);
 }
@@ -78,7 +78,7 @@ int restore_sigcontext(struct pt_regs *regs,
 }
 
 /* sigreturn() returns long since it restores r0 in the interrupted code. */
-long _sys_rt_sigreturn(struct pt_regs *regs)
+SYSCALL_DEFINE1(rt_sigreturn, struct pt_regs *, regs)
 {
 	struct rt_sigframe __user *frame =
 		(struct rt_sigframe __user *)(regs->sp);

arch/tile/kernel/sys.c

@@ -110,6 +110,15 @@ SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
 #define sys_sync_file_range sys_sync_file_range2
 #endif
 
+/* Call the trampolines to manage pt_regs where necessary. */
+#define sys_execve _sys_execve
+#define sys_sigaltstack _sys_sigaltstack
+#define sys_rt_sigreturn _sys_rt_sigreturn
+#define sys_clone _sys_clone
+#ifndef __tilegx__
+#define sys_cmpxchg_badaddr _sys_cmpxchg_badaddr
+#endif
+
 /*
  * Note that we can't include <linux/unistd.h> here since the header
  * guard will defeat us; <asm/unistd.h> checks for __SYSCALL as well.