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

2 files changed, 59 insertions, 19 deletions

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);