x86: get rid of pt_regs argument in sigreturn variants

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/x86/ia32/ia32_signal.c

@@ -215,8 +215,9 @@ static int ia32_restore_sigcontext(struct pt_regs *regs,
 	return err;
 }
 
-asmlinkage long sys32_sigreturn(struct pt_regs *regs)
+asmlinkage long sys32_sigreturn(void)
 {
+	struct pt_regs *regs = current_pt_regs();
 	struct sigframe_ia32 __user *frame = (struct sigframe_ia32 __user *)(regs->sp-8);
 	sigset_t set;
 	unsigned int ax;
@@ -241,8 +242,9 @@ asmlinkage long sys32_sigreturn(struct pt_regs *regs)
 	return 0;
 }
 
-asmlinkage long sys32_rt_sigreturn(struct pt_regs *regs)
+asmlinkage long sys32_rt_sigreturn(void)
 {
+	struct pt_regs *regs = current_pt_regs();
 	struct rt_sigframe_ia32 __user *frame;
 	sigset_t set;
 	unsigned int ax;

arch/x86/ia32/ia32entry.S

@@ -456,17 +456,16 @@ ia32_badsys:
 	ALIGN
 GLOBAL(\label)
 	leaq \func(%rip),%rax
-	leaq -ARGOFFSET+8(%rsp),\arg	/* 8 for return address */
 	jmp  ia32_ptregs_common	
 	.endm
 
 	CFI_STARTPROC32
 
-	PTREGSCALL stub32_rt_sigreturn, sys32_rt_sigreturn, %rdi
-	PTREGSCALL stub32_sigreturn, sys32_sigreturn, %rdi
-	PTREGSCALL stub32_execve, compat_sys_execve, %rcx
-	PTREGSCALL stub32_fork, sys_fork, %rdi
-	PTREGSCALL stub32_vfork, sys_vfork, %rdi
+	PTREGSCALL stub32_rt_sigreturn, sys32_rt_sigreturn
+	PTREGSCALL stub32_sigreturn, sys32_sigreturn
+	PTREGSCALL stub32_execve, compat_sys_execve
+	PTREGSCALL stub32_fork, sys_fork
+	PTREGSCALL stub32_vfork, sys_vfork
 
 	ALIGN
 GLOBAL(stub32_clone)

arch/x86/include/asm/sys_ia32.h

@@ -69,8 +69,8 @@ asmlinkage long sys32_fallocate(int, int, unsigned,
 
 /* ia32/ia32_signal.c */
 asmlinkage long sys32_sigsuspend(int, int, old_sigset_t);
-asmlinkage long sys32_sigreturn(struct pt_regs *);
-asmlinkage long sys32_rt_sigreturn(struct pt_regs *);
+asmlinkage long sys32_sigreturn(void);
+asmlinkage long sys32_rt_sigreturn(void);
 
 /* ia32/ipc32.c */
 asmlinkage long sys32_ipc(u32, int, int, int, compat_uptr_t, u32);

arch/x86/include/asm/syscalls.h

@@ -24,7 +24,7 @@ asmlinkage long sys_iopl(unsigned int);
 asmlinkage int sys_modify_ldt(int, void __user *, unsigned long);
 
 /* kernel/signal.c */
-long sys_rt_sigreturn(struct pt_regs *);
+long sys_rt_sigreturn(void);
 
 /* kernel/tls.c */
 asmlinkage int sys_set_thread_area(struct user_desc __user *);
@@ -37,7 +37,7 @@ asmlinkage int sys_get_thread_area(struct user_desc __user *);
 asmlinkage int sys_sigsuspend(int, int, old_sigset_t);
 asmlinkage int sys_sigaction(int, const struct old_sigaction __user *,
 			     struct old_sigaction __user *);
-unsigned long sys_sigreturn(struct pt_regs *);
+unsigned long sys_sigreturn(void);
 
 /* kernel/vm86_32.c */
 int sys_vm86old(struct vm86_struct __user *, struct pt_regs *);

arch/x86/kernel/entry_32.S

@@ -702,12 +702,6 @@ END(syscall_badsys)
 /*
  * System calls that need a pt_regs pointer.
  */
-#define PTREGSCALL0(name) \
-ENTRY(ptregs_##name) ;  \
-	leal 4(%esp),%eax; \
-	jmp sys_##name; \
-ENDPROC(ptregs_##name)
-
 #define PTREGSCALL1(name) \
 ENTRY(ptregs_##name) ; \
 	leal 4(%esp),%edx; \
@@ -723,23 +717,6 @@ ENTRY(ptregs_##name) ; \
 	jmp sys_##name; \
 ENDPROC(ptregs_##name)
 
-#define PTREGSCALL3(name) \
-ENTRY(ptregs_##name) ; \
-	CFI_STARTPROC; \
-	leal 4(%esp),%eax; \
-	pushl_cfi %eax; \
-	movl PT_EDX(%eax),%ecx; \
-	movl PT_ECX(%eax),%edx; \
-	movl PT_EBX(%eax),%eax; \
-	call sys_##name; \
-	addl $4,%esp; \
-	CFI_ADJUST_CFA_OFFSET -4; \
-	ret; \
-	CFI_ENDPROC; \
-ENDPROC(ptregs_##name)
-
-PTREGSCALL0(sigreturn)
-PTREGSCALL0(rt_sigreturn)
 PTREGSCALL2(vm86)
 PTREGSCALL1(vm86old)
 

arch/x86/kernel/entry_64.S

@@ -896,7 +896,6 @@ ENTRY(stub_rt_sigreturn)
 	addq $8, %rsp
 	PARTIAL_FRAME 0
 	SAVE_REST
-	movq %rsp,%rdi
 	FIXUP_TOP_OF_STACK %r11
 	call sys_rt_sigreturn
 	movq %rax,RAX(%rsp) # fixme, this could be done at the higher layer
@@ -911,7 +910,6 @@ ENTRY(stub_x32_rt_sigreturn)
 	addq $8, %rsp
 	PARTIAL_FRAME 0
 	SAVE_REST
-	movq %rsp,%rdi
 	FIXUP_TOP_OF_STACK %r11
 	call sys32_x32_rt_sigreturn
 	movq %rax,RAX(%rsp) # fixme, this could be done at the higher layer

arch/x86/kernel/signal.c

@@ -597,8 +597,9 @@ sys_sigaction(int sig, const struct old_sigaction __user *act,
  * Do a signal return; undo the signal stack.
  */
 #ifdef CONFIG_X86_32
-unsigned long sys_sigreturn(struct pt_regs *regs)
+unsigned long sys_sigreturn(void)
 {
+	struct pt_regs *regs = current_pt_regs();
 	struct sigframe __user *frame;
 	unsigned long ax;
 	sigset_t set;
@@ -625,8 +626,9 @@ unsigned long sys_sigreturn(struct pt_regs *regs)
 }
 #endif /* CONFIG_X86_32 */
 
-long sys_rt_sigreturn(struct pt_regs *regs)
+long sys_rt_sigreturn(void)
 {
+	struct pt_regs *regs = current_pt_regs();
 	struct rt_sigframe __user *frame;
 	unsigned long ax;
 	sigset_t set;
@@ -843,8 +845,9 @@ void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
 }
 
 #ifdef CONFIG_X86_X32_ABI
-asmlinkage long sys32_x32_rt_sigreturn(struct pt_regs *regs)
+asmlinkage long sys32_x32_rt_sigreturn(void)
 {
+	struct pt_regs *regs = current_pt_regs();
 	struct rt_sigframe_x32 __user *frame;
 	sigset_t set;
 	unsigned long ax;

arch/x86/syscalls/syscall_32.tbl

@@ -125,7 +125,7 @@
 116	i386	sysinfo			sys_sysinfo			compat_sys_sysinfo
 117	i386	ipc			sys_ipc				sys32_ipc
 118	i386	fsync			sys_fsync
-119	i386	sigreturn		ptregs_sigreturn		stub32_sigreturn
+119	i386	sigreturn		sys_sigreturn			stub32_sigreturn
 120	i386	clone			sys_clone			stub32_clone
 121	i386	setdomainname		sys_setdomainname
 122	i386	uname			sys_newuname
@@ -179,7 +179,7 @@
 170	i386	setresgid		sys_setresgid16
 171	i386	getresgid		sys_getresgid16
 172	i386	prctl			sys_prctl
-173	i386	rt_sigreturn		ptregs_rt_sigreturn		stub32_rt_sigreturn
+173	i386	rt_sigreturn		sys_rt_sigreturn		stub32_rt_sigreturn
 174	i386	rt_sigaction		sys_rt_sigaction		sys32_rt_sigaction
 175	i386	rt_sigprocmask		sys_rt_sigprocmask
 176	i386	rt_sigpending		sys_rt_sigpending		sys32_rt_sigpending

arch/x86/um/signal.c

@@ -464,7 +464,7 @@ int setup_signal_stack_si(unsigned long stack_top, int sig,
 	return 0;
 }
 
-long sys_sigreturn(struct pt_regs *regs)
+long sys_sigreturn(void)
 {
 	unsigned long sp = PT_REGS_SP(&current->thread.regs);
 	struct sigframe __user *frame = (struct sigframe __user *)(sp - 8);
@@ -577,7 +577,7 @@ int setup_signal_stack_si(unsigned long stack_top, int sig,
 }
 #endif
 
-long sys_rt_sigreturn(struct pt_regs *regs)
+long sys_rt_sigreturn(void)
 {
 	unsigned long sp = PT_REGS_SP(&current->thread.regs);
 	struct rt_sigframe __user *frame =
@@ -601,14 +601,3 @@ long sys_rt_sigreturn(struct pt_regs *regs)
 	force_sig(SIGSEGV, current);
 	return 0;
 }
-
-#ifdef CONFIG_X86_32
-long ptregs_sigreturn(void)
-{
-	return sys_sigreturn(NULL);
-}
-long ptregs_rt_sigreturn(void)
-{
-	return sys_rt_sigreturn(NULL);
-}
-#endif