Merge branch 'x86-entry-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 syscall entry updates from Ingo Molnar:
 "These changes relate to the preparatory cleanup of syscall function
  type signatures - to fix indirect call mismatches with Control-Flow
  Integrity (CFI) checking.

  No change in behavior intended"

* 'x86-entry-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Use the correct function type for native_set_fixmap()
  syscalls/x86: Fix function types in COND_SYSCALL
  syscalls/x86: Use the correct function type for sys_ni_syscall
  syscalls/x86: Use COMPAT_SYSCALL_DEFINE0 for IA32 (rt_)sigreturn
  syscalls/x86: Wire up COMPAT_SYSCALL_DEFINE0
  syscalls/x86: Use the correct function type in SYSCALL_DEFINE0

7 files changed, 81 insertions, 36 deletions

diff --git a/arch/x86/entry/syscall_32.c b/arch/x86/entry/syscall_32.c
index aa3336a7cb15..7d17b3addbbb 100644
--- a/arch/x86/entry/syscall_32.c
+++ b/arch/x86/entry/syscall_32.c
@@ -10,13 +10,11 @@
 #ifdef CONFIG_IA32_EMULATION
 /* On X86_64, we use struct pt_regs * to pass parameters to syscalls */
 #define __SYSCALL_I386(nr, sym, qual) extern asmlinkage long sym(const struct pt_regs *);
-
-/* this is a lie, but it does not hurt as sys_ni_syscall just returns -EINVAL */
-extern asmlinkage long sys_ni_syscall(const struct pt_regs *);
-
+#define __sys_ni_syscall __ia32_sys_ni_syscall
 #else /* CONFIG_IA32_EMULATION */
 #define __SYSCALL_I386(nr, sym, qual) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
 extern asmlinkage long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
+#define __sys_ni_syscall sys_ni_syscall
 #endif /* CONFIG_IA32_EMULATION */
 
 #include <asm/syscalls_32.h>
@@ -29,6 +27,6 @@ __visible const sys_call_ptr_t ia32_sys_call_table[__NR_syscall_compat_max+1] =
 	 * Smells like a compiler bug -- it doesn't work
 	 * when the & below is removed.
 	 */
-	[0 ... __NR_syscall_compat_max] = &sys_ni_syscall,
+	[0 ... __NR_syscall_compat_max] = &__sys_ni_syscall,
 #include <asm/syscalls_32.h>
 };
diff --git a/arch/x86/entry/syscall_64.c b/arch/x86/entry/syscall_64.c
index b1bf31713374..adf619a856e8 100644
--- a/arch/x86/entry/syscall_64.c
+++ b/arch/x86/entry/syscall_64.c
@@ -4,11 +4,17 @@
 #include <linux/linkage.h>
 #include <linux/sys.h>
 #include <linux/cache.h>
+#include <linux/syscalls.h>
 #include <asm/asm-offsets.h>
 #include <asm/syscall.h>
 
-/* this is a lie, but it does not hurt as sys_ni_syscall just returns -EINVAL */
-extern asmlinkage long sys_ni_syscall(const struct pt_regs *);
+extern asmlinkage long sys_ni_syscall(void);
+
+SYSCALL_DEFINE0(ni_syscall)
+{
+	return sys_ni_syscall();
+}
+
 #define __SYSCALL_64(nr, sym, qual) extern asmlinkage long sym(const struct pt_regs *);
 #define __SYSCALL_X32(nr, sym, qual) __SYSCALL_64(nr, sym, qual)
 #include <asm/syscalls_64.h>
@@ -23,7 +29,7 @@ asmlinkage const sys_call_ptr_t sys_call_table[__NR_syscall_max+1] = {
 	 * Smells like a compiler bug -- it doesn't work
 	 * when the & below is removed.
 	 */
-	[0 ... __NR_syscall_max] = &sys_ni_syscall,
+	[0 ... __NR_syscall_max] = &__x64_sys_ni_syscall,
 #include <asm/syscalls_64.h>
 };
 
@@ -40,7 +46,7 @@ asmlinkage const sys_call_ptr_t x32_sys_call_table[__NR_syscall_x32_max+1] = {
 	 * Smells like a compiler bug -- it doesn't work
 	 * when the & below is removed.
 	 */
-	[0 ... __NR_syscall_x32_max] = &sys_ni_syscall,
+	[0 ... __NR_syscall_x32_max] = &__x64_sys_ni_syscall,
 #include <asm/syscalls_64.h>
 };
 
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index 3fe02546aed3..15908eb9b17e 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -124,13 +124,13 @@
 110	i386	iopl			sys_iopl			__ia32_sys_iopl
 111	i386	vhangup			sys_vhangup			__ia32_sys_vhangup
 112	i386	idle
-113	i386	vm86old			sys_vm86old			sys_ni_syscall
+113	i386	vm86old			sys_vm86old			__ia32_sys_ni_syscall
 114	i386	wait4			sys_wait4			__ia32_compat_sys_wait4
 115	i386	swapoff			sys_swapoff			__ia32_sys_swapoff
 116	i386	sysinfo			sys_sysinfo			__ia32_compat_sys_sysinfo
 117	i386	ipc			sys_ipc				__ia32_compat_sys_ipc
 118	i386	fsync			sys_fsync			__ia32_sys_fsync
-119	i386	sigreturn		sys_sigreturn			sys32_sigreturn
+119	i386	sigreturn		sys_sigreturn			__ia32_compat_sys_sigreturn
 120	i386	clone			sys_clone			__ia32_compat_sys_x86_clone
 121	i386	setdomainname		sys_setdomainname		__ia32_sys_setdomainname
 122	i386	uname			sys_newuname			__ia32_sys_newuname
@@ -177,14 +177,14 @@
 163	i386	mremap			sys_mremap			__ia32_sys_mremap
 164	i386	setresuid		sys_setresuid16			__ia32_sys_setresuid16
 165	i386	getresuid		sys_getresuid16			__ia32_sys_getresuid16
-166	i386	vm86			sys_vm86			sys_ni_syscall
+166	i386	vm86			sys_vm86			__ia32_sys_ni_syscall
 167	i386	query_module
 168	i386	poll			sys_poll			__ia32_sys_poll
 169	i386	nfsservctl
 170	i386	setresgid		sys_setresgid16			__ia32_sys_setresgid16
 171	i386	getresgid		sys_getresgid16			__ia32_sys_getresgid16
 172	i386	prctl			sys_prctl			__ia32_sys_prctl
-173	i386	rt_sigreturn		sys_rt_sigreturn		sys32_rt_sigreturn
+173	i386	rt_sigreturn		sys_rt_sigreturn		__ia32_compat_sys_rt_sigreturn
 174	i386	rt_sigaction		sys_rt_sigaction		__ia32_compat_sys_rt_sigaction
 175	i386	rt_sigprocmask		sys_rt_sigprocmask		__ia32_compat_sys_rt_sigprocmask
 176	i386	rt_sigpending		sys_rt_sigpending		__ia32_compat_sys_rt_sigpending
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index 1cee10091b9f..30416d7f19d4 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -21,6 +21,7 @@
 #include <linux/personality.h>
 #include <linux/compat.h>
 #include <linux/binfmts.h>
+#include <linux/syscalls.h>
 #include <asm/ucontext.h>
 #include <linux/uaccess.h>
 #include <asm/fpu/internal.h>
@@ -118,7 +119,7 @@ static int ia32_restore_sigcontext(struct pt_regs *regs,
 	return err;
 }
 
-asmlinkage long sys32_sigreturn(void)
+COMPAT_SYSCALL_DEFINE0(sigreturn)
 {
 	struct pt_regs *regs = current_pt_regs();
 	struct sigframe_ia32 __user *frame = (struct sigframe_ia32 __user *)(regs->sp-8);
@@ -144,7 +145,7 @@ badframe:
 	return 0;
 }
 
-asmlinkage long sys32_rt_sigreturn(void)
+COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
 {
 	struct pt_regs *regs = current_pt_regs();
 	struct rt_sigframe_ia32 __user *frame;
diff --git a/arch/x86/include/asm/fixmap.h b/arch/x86/include/asm/fixmap.h
index 0c47aa82e2e2..28183ee3cc42 100644
--- a/arch/x86/include/asm/fixmap.h
+++ b/arch/x86/include/asm/fixmap.h
@@ -156,7 +156,7 @@ extern pte_t *kmap_pte;
 extern pte_t *pkmap_page_table;
 
 void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);
-void native_set_fixmap(enum fixed_addresses idx,
+void native_set_fixmap(unsigned /* enum fixed_addresses */ idx,
 		       phys_addr_t phys, pgprot_t flags);
 
 #ifndef CONFIG_PARAVIRT_XXL
diff --git a/arch/x86/include/asm/syscall_wrapper.h b/arch/x86/include/asm/syscall_wrapper.h
index e046a405743d..e2389ce9bf58 100644
--- a/arch/x86/include/asm/syscall_wrapper.h
+++ b/arch/x86/include/asm/syscall_wrapper.h
@@ -6,6 +6,8 @@
 #ifndef _ASM_X86_SYSCALL_WRAPPER_H
 #define _ASM_X86_SYSCALL_WRAPPER_H
 
+struct pt_regs;
+
 /* Mapping of registers to parameters for syscalls on x86-64 and x32 */
 #define SC_X86_64_REGS_TO_ARGS(x, ...)					\
 	__MAP(x,__SC_ARGS						\
@@ -28,13 +30,21 @@
  * kernel/sys_ni.c and SYS_NI in kernel/time/posix-stubs.c to cover this
  * case as well.
  */
+#define __IA32_COMPAT_SYS_STUB0(x, name)				\
+	asmlinkage long __ia32_compat_sys_##name(const struct pt_regs *regs);\
+	ALLOW_ERROR_INJECTION(__ia32_compat_sys_##name, ERRNO);		\
+	asmlinkage long __ia32_compat_sys_##name(const struct pt_regs *regs)\
+	{								\
+		return __se_compat_sys_##name();			\
+	}
+
 #define __IA32_COMPAT_SYS_STUBx(x, name, ...)				\
 	asmlinkage long __ia32_compat_sys##name(const struct pt_regs *regs);\
 	ALLOW_ERROR_INJECTION(__ia32_compat_sys##name, ERRNO);		\
 	asmlinkage long __ia32_compat_sys##name(const struct pt_regs *regs)\
 	{								\
 		return __se_compat_sys##name(SC_IA32_REGS_TO_ARGS(x,__VA_ARGS__));\
-	}								\
+	}
 
 #define __IA32_SYS_STUBx(x, name, ...)					\
 	asmlinkage long __ia32_sys##name(const struct pt_regs *regs);	\
@@ -48,16 +58,23 @@
  * To keep the naming coherent, re-define SYSCALL_DEFINE0 to create an alias
  * named __ia32_sys_*()
  */
-#define SYSCALL_DEFINE0(sname)					\
-	SYSCALL_METADATA(_##sname, 0);				\
-	asmlinkage long __x64_sys_##sname(void);		\
-	ALLOW_ERROR_INJECTION(__x64_sys_##sname, ERRNO);	\
-	SYSCALL_ALIAS(__ia32_sys_##sname, __x64_sys_##sname);	\
-	asmlinkage long __x64_sys_##sname(void)
 
-#define COND_SYSCALL(name)						\
-	cond_syscall(__x64_sys_##name);					\
-	cond_syscall(__ia32_sys_##name)
+#define SYSCALL_DEFINE0(sname)						\
+	SYSCALL_METADATA(_##sname, 0);					\
+	asmlinkage long __x64_sys_##sname(const struct pt_regs *__unused);\
+	ALLOW_ERROR_INJECTION(__x64_sys_##sname, ERRNO);		\
+	SYSCALL_ALIAS(__ia32_sys_##sname, __x64_sys_##sname);		\
+	asmlinkage long __x64_sys_##sname(const struct pt_regs *__unused)
+
+#define COND_SYSCALL(name)							\
+	asmlinkage __weak long __x64_sys_##name(const struct pt_regs *__unused)	\
+	{									\
+		return sys_ni_syscall();					\
+	}									\
+	asmlinkage __weak long __ia32_sys_##name(const struct pt_regs *__unused)\
+	{									\
+		return sys_ni_syscall();					\
+	}
 
 #define SYS_NI(name)							\
 	SYSCALL_ALIAS(__x64_sys_##name, sys_ni_posix_timers);		\
@@ -75,15 +92,24 @@
  * of the x86-64-style parameter ordering of x32 syscalls. The syscalls common
  * with x86_64 obviously do not need such care.
  */
+#define __X32_COMPAT_SYS_STUB0(x, name, ...)				\
+	asmlinkage long __x32_compat_sys_##name(const struct pt_regs *regs);\
+	ALLOW_ERROR_INJECTION(__x32_compat_sys_##name, ERRNO);		\
+	asmlinkage long __x32_compat_sys_##name(const struct pt_regs *regs)\
+	{								\
+		return __se_compat_sys_##name();\
+	}
+
 #define __X32_COMPAT_SYS_STUBx(x, name, ...)				\
 	asmlinkage long __x32_compat_sys##name(const struct pt_regs *regs);\
 	ALLOW_ERROR_INJECTION(__x32_compat_sys##name, ERRNO);		\
 	asmlinkage long __x32_compat_sys##name(const struct pt_regs *regs)\
 	{								\
 		return __se_compat_sys##name(SC_X86_64_REGS_TO_ARGS(x,__VA_ARGS__));\
-	}								\
+	}
 
 #else /* CONFIG_X86_X32 */
+#define __X32_COMPAT_SYS_STUB0(x, name)
 #define __X32_COMPAT_SYS_STUBx(x, name, ...)
 #endif /* CONFIG_X86_X32 */
 
@@ -94,6 +120,17 @@
  * mapping of registers to parameters, we need to generate stubs for each
  * of them.
  */
+#define COMPAT_SYSCALL_DEFINE0(name)					\
+	static long __se_compat_sys_##name(void);			\
+	static inline long __do_compat_sys_##name(void);		\
+	__IA32_COMPAT_SYS_STUB0(x, name)				\
+	__X32_COMPAT_SYS_STUB0(x, name)					\
+	static long __se_compat_sys_##name(void)			\
+	{								\
+		return __do_compat_sys_##name();			\
+	}								\
+	static inline long __do_compat_sys_##name(void)
+
 #define COMPAT_SYSCALL_DEFINEx(x, name, ...)					\
 	static long __se_compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__));	\
 	static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));\
@@ -181,15 +218,19 @@
  * macros to work correctly.
  */
 #ifndef SYSCALL_DEFINE0
-#define SYSCALL_DEFINE0(sname)					\
-	SYSCALL_METADATA(_##sname, 0);				\
-	asmlinkage long __x64_sys_##sname(void);		\
-	ALLOW_ERROR_INJECTION(__x64_sys_##sname, ERRNO);	\
-	asmlinkage long __x64_sys_##sname(void)
+#define SYSCALL_DEFINE0(sname)						\
+	SYSCALL_METADATA(_##sname, 0);					\
+	asmlinkage long __x64_sys_##sname(const struct pt_regs *__unused);\
+	ALLOW_ERROR_INJECTION(__x64_sys_##sname, ERRNO);		\
+	asmlinkage long __x64_sys_##sname(const struct pt_regs *__unused)
 #endif
 
 #ifndef COND_SYSCALL
-#define COND_SYSCALL(name) cond_syscall(__x64_sys_##name)
+#define COND_SYSCALL(name) 							\
+	asmlinkage __weak long __x64_sys_##name(const struct pt_regs *__unused)	\
+	{									\
+		return sys_ni_syscall();					\
+	}
 #endif
 
 #ifndef SYS_NI
@@ -201,7 +242,6 @@
  * For VSYSCALLS, we need to declare these three syscalls with the new
  * pt_regs-based calling convention for in-kernel use.
  */
-struct pt_regs;
 asmlinkage long __x64_sys_getcpu(const struct pt_regs *regs);
 asmlinkage long __x64_sys_gettimeofday(const struct pt_regs *regs);
 asmlinkage long __x64_sys_time(const struct pt_regs *regs);
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index 3e4b9035bb9a..7bd2c3a52297 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -643,8 +643,8 @@ void __native_set_fixmap(enum fixed_addresses idx, pte_t pte)
 	fixmaps_set++;
 }
 
-void native_set_fixmap(enum fixed_addresses idx, phys_addr_t phys,
-		       pgprot_t flags)
+void native_set_fixmap(unsigned /* enum fixed_addresses */ idx,
+		       phys_addr_t phys, pgprot_t flags)
 {
 	/* Sanitize 'prot' against any unsupported bits: */
 	pgprot_val(flags) &= __default_kernel_pte_mask;