syscalls/core, syscalls/x86: Clean up compat syscall stub naming convention

Tidy the naming convention for compat syscall subs. Hints which describe
the purpose of the stub go in front and receive a double underscore to
denote that they are generated on-the-fly by the COMPAT_SYSCALL_DEFINEx()
macro.

For the generic case, this means:

t            kernel_waitid	# common C function (see kernel/exit.c)

    __do_compat_sys_waitid	# inlined helper doing the actual work
				# (takes original parameters as declared)

T   __se_compat_sys_waitid	# sign-extending C function calling inlined
				# helper (takes parameters of type long,
				# casts them to unsigned long and then to
				# the declared type)

T        compat_sys_waitid      # alias to __se_compat_sys_waitid()
				# (taking parameters as declared), to
				# be included in syscall table

For x86, the naming is as follows:

t            kernel_waitid	# common C function (see kernel/exit.c)

    __do_compat_sys_waitid	# inlined helper doing the actual work
				# (takes original parameters as declared)

t   __se_compat_sys_waitid      # sign-extending C function calling inlined
				# helper (takes parameters of type long,
				# casts them to unsigned long and then to
				# the declared type)

T __ia32_compat_sys_waitid	# IA32_EMULATION 32-bit-ptregs -> C stub,
				# calls __se_compat_sys_waitid(); to be
				# included in syscall table

T  __x32_compat_sys_waitid	# x32 64-bit-ptregs -> C stub, calls
				# __se_compat_sys_waitid(); to be included
				# in syscall table

If only one of IA32_EMULATION and x32 is enabled, __se_compat_sys_waitid()
may be inlined into the stub __{ia32,x32}_compat_sys_waitid().

Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180409105145.5364-3-linux@dominikbrodowski.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>

2 files changed, 23 insertions, 23 deletions

diff --git a/arch/x86/include/asm/syscall_wrapper.h b/arch/x86/include/asm/syscall_wrapper.h
index 798a3c2bff4f..8d0951cfc2d4 100644
--- a/arch/x86/include/asm/syscall_wrapper.h
+++ b/arch/x86/include/asm/syscall_wrapper.h
@@ -29,11 +29,11 @@
  * case as well.
  */
 #define COMPAT_SC_IA32_STUBx(x, name, ...)				\
-	asmlinkage long __compat_sys_ia32##name(const struct pt_regs *regs);\
-	ALLOW_ERROR_INJECTION(__compat_sys_ia32##name, ERRNO);		\
-	asmlinkage long __compat_sys_ia32##name(const struct pt_regs *regs)\
+	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 c_SyS##name(SC_IA32_REGS_TO_ARGS(x,__VA_ARGS__));\
+		return __se_compat_sys##name(SC_IA32_REGS_TO_ARGS(x,__VA_ARGS__));\
 	}								\
 
 #define SC_IA32_WRAPPERx(x, name, ...)					\
@@ -65,11 +65,11 @@
  * with x86_64 obviously do not need such care.
  */
 #define COMPAT_SC_X32_STUBx(x, name, ...)				\
-	asmlinkage long __compat_sys_x32##name(const struct pt_regs *regs);\
-	ALLOW_ERROR_INJECTION(__compat_sys_x32##name, ERRNO);		\
-	asmlinkage long __compat_sys_x32##name(const struct pt_regs *regs)\
+	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 c_SyS##name(SC_X86_64_REGS_TO_ARGS(x,__VA_ARGS__));\
+		return __se_compat_sys##name(SC_X86_64_REGS_TO_ARGS(x,__VA_ARGS__));\
 	}								\
 
 #else /* CONFIG_X86_X32 */
@@ -84,16 +84,16 @@
  * of them. There is no need to implement COMPAT_SYSCALL_DEFINE0, as it is
  * unused on x86.
  */
-#define COMPAT_SYSCALL_DEFINEx(x, name, ...)				\
-	static long c_SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__));	\
-	static inline long C_SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__));\
-	COMPAT_SC_IA32_STUBx(x, name, __VA_ARGS__)			\
-	COMPAT_SC_X32_STUBx(x, name, __VA_ARGS__)			\
-	static long c_SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__))		\
-	{								\
-		return C_SYSC##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__));	\
-	}								\
-	static inline long C_SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__))
+#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__));\
+	COMPAT_SC_IA32_STUBx(x, name, __VA_ARGS__)				\
+	COMPAT_SC_X32_STUBx(x, name, __VA_ARGS__)				\
+	static long __se_compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__))	\
+	{									\
+		return __do_compat_sys##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__));\
+	}									\
+	static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
 
 /*
  * As some compat syscalls may not be implemented, we need to expand
@@ -101,12 +101,12 @@
  * kernel/time/posix-stubs.c to cover this case as well.
  */
 #define COND_SYSCALL_COMPAT(name) 					\
-	cond_syscall(__compat_sys_ia32_##name);				\
-	cond_syscall(__compat_sys_x32_##name)
+	cond_syscall(__ia32_compat_sys_##name);				\
+	cond_syscall(__x32_compat_sys_##name)
 
 #define COMPAT_SYS_NI(name)						\
-	SYSCALL_ALIAS(__compat_sys_ia32_##name, sys_ni_posix_timers);	\
-	SYSCALL_ALIAS(__compat_sys_x32_##name, sys_ni_posix_timers)
+	SYSCALL_ALIAS(__ia32_compat_sys_##name, sys_ni_posix_timers);	\
+	SYSCALL_ALIAS(__x32_compat_sys_##name, sys_ni_posix_timers)
 
 #endif /* CONFIG_COMPAT */
 
diff --git a/arch/x86/include/asm/syscalls.h b/arch/x86/include/asm/syscalls.h
index d4d18d94695c..9fa979dd0d9d 100644
--- a/arch/x86/include/asm/syscalls.h
+++ b/arch/x86/include/asm/syscalls.h
@@ -20,7 +20,7 @@
 long ksys_ioperm(unsigned long from, unsigned long num, int turn_on);
 
 #ifdef CONFIG_X86_32
-/* 
+/*
  * These definitions are only valid on pure 32-bit systems; x86-64 uses a
  * different syscall calling convention
  */