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| author | Dominik Brodowski <linux@dominikbrodowski.net> | 2018-04-09 12:51:43 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-04-09 16:47:28 +0200 |
| commit | 5ac9efa3c50d7caff9f3933bb8a3ad1139d92d92 (patch) | |
| tree | 8911252894d4f412bf6e2f1f1b4378a9f366d966 /Documentation | |
| parent | syscalls/core, syscalls/x86: Clean up syscall stub naming convention (diff) | |
| download | linux-5ac9efa3c50d7caff9f3933bb8a3ad1139d92d92.tar.xz linux-5ac9efa3c50d7caff9f3933bb8a3ad1139d92d92.zip | |
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>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/process/adding-syscalls.rst | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/Documentation/process/adding-syscalls.rst b/Documentation/process/adding-syscalls.rst index 314c8bf6f2a2..0d4f29bc798b 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 |