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>
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 @@
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 @@
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
