x86/syscalls: Add syscall entry qualifiers
This will let us specify something like 'sys_xyz/foo' instead of
'sys_xyz' in the syscall table, where the 'foo' qualifier conveys
some extra information to the C code.
The intent is to allow things like sys_execve/ptregs to indicate
that sys_execve() touches pt_regs.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.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/2de06e33dce62556b3ec662006fcb295504e296e.1454022279.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/arch/x86/entry/syscalls/syscalltbl.sh b/arch/x86/entry/syscalls/syscalltbl.sh
index b81479c..cd3d301 100644
--- a/arch/x86/entry/syscalls/syscalltbl.sh
+++ b/arch/x86/entry/syscalls/syscalltbl.sh
@@ -3,6 +3,19 @@
in="$1"
out="$2"
+syscall_macro() {
+ abi="$1"
+ nr="$2"
+ entry="$3"
+
+ # Entry can be either just a function name or "function/qualifier"
+ real_entry="${entry%%/*}"
+ qualifier="${entry:${#real_entry}}" # Strip the function name
+ qualifier="${qualifier:1}" # Strip the slash, if any
+
+ echo "__SYSCALL_${abi}($nr, $real_entry, $qualifier)"
+}
+
emit() {
abi="$1"
nr="$2"
@@ -16,15 +29,15 @@
if [ -z "$compat" ]; then
if [ -n "$entry" ]; then
- echo "__SYSCALL_${abi}($nr, $entry)"
+ syscall_macro "$abi" "$nr" "$entry"
fi
else
echo "#ifdef CONFIG_X86_32"
if [ -n "$entry" ]; then
- echo "__SYSCALL_${abi}($nr, $entry)"
+ syscall_macro "$abi" "$nr" "$entry"
fi
echo "#else"
- echo "__SYSCALL_${abi}($nr, $compat)"
+ syscall_macro "$abi" "$nr" "$compat"
echo "#endif"
fi
}