From 5ac9efa3c50d7caff9f3933bb8a3ad1139d92d92 Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Mon, 9 Apr 2018 12:51:43 +0200 Subject: 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 Signed-off-by: Dominik Brodowski Cc: Al Viro Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20180409105145.5364-3-linux@dominikbrodowski.net Signed-off-by: Ingo Molnar --- include/linux/compat.h | 29 +++++++++++++++++------------ 1 file changed, 17 insertions(+), 12 deletions(-) (limited to 'include/linux/compat.h') diff --git a/include/linux/compat.h b/include/linux/compat.h index 2d85ec5cfda2..aca050aac7b6 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -63,19 +63,24 @@ #define COMPAT_SYSCALL_DEFINE6(name, ...) \ COMPAT_SYSCALL_DEFINEx(6, _##name, __VA_ARGS__) +/* + * The asmlinkage stub is aliased to a function named __se_compat_sys_*() which + * sign-extends 32-bit ints to longs whenever needed. The actual work is + * done within __do_compat_sys_*(). + */ #ifndef COMPAT_SYSCALL_DEFINEx -#define COMPAT_SYSCALL_DEFINEx(x, name, ...) \ - asmlinkage long compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));\ - asmlinkage long compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))\ - __attribute__((alias(__stringify(compat_SyS##name)))); \ - ALLOW_ERROR_INJECTION(compat_sys##name, ERRNO); \ - static inline long C_SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__));\ - asmlinkage long compat_SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__));\ - asmlinkage long compat_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, ...) \ + asmlinkage long compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \ + asmlinkage long compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \ + __attribute__((alias(__stringify(__se_compat_sys##name)))); \ + ALLOW_ERROR_INJECTION(compat_sys##name, ERRNO); \ + static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));\ + asmlinkage long __se_compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \ + asmlinkage 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__)) #endif /* COMPAT_SYSCALL_DEFINEx */ #ifndef compat_user_stack_pointer -- cgit v1.2.3