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 --- Documentation/process/adding-syscalls.rst | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'Documentation/process') diff --git a/Documentation/process/adding-syscalls.rst b/Documentation/process/adding-syscalls.rst index 314c8bf..0d4f29b 100644 --- a/Documentation/process/adding-syscalls.rst +++ b/Documentation/process/adding-syscalls.rst @@ -360,7 +360,7 @@ First, the entry in ``arch/x86/entry/syscalls/syscall_32.tbl`` gets an extra column to indicate that a 32-bit userspace program running on a 64-bit kernel should hit the compat entry point:: - 380 i386 xyzzy sys_xyzzy compat_sys_xyzzy + 380 i386 xyzzy sys_xyzzy __ia32_compat_sys_xyzzy Second, you need to figure out what should happen for the x32 ABI version of the new system call. There's a choice here: the layout of the arguments @@ -373,7 +373,7 @@ the compatibility wrapper:: 333 64 xyzzy sys_xyzzy ... - 555 x32 xyzzy compat_sys_xyzzy + 555 x32 xyzzy __x32_compat_sys_xyzzy If no pointers are involved, then it is preferable to re-use the 64-bit system call for the x32 ABI (and consequently the entry in -- cgit v1.1