[PATCH 06/12] x86/syscalls: Add syscall entry qualifiers

From: Andy Lutomirski
Date: Mon Dec 07 2015 - 16:55:33 EST


This will let us specify something like sys_xyz/foo instead of
sys_xyz in the syscall table, where the foo conveys some 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@xxxxxxxxxx>
---
arch/x86/entry/syscall_32.c | 4 ++--
arch/x86/entry/syscall_64.c | 4 ++--
arch/x86/entry/syscalls/syscalltbl.sh | 19 ++++++++++++++++---
arch/x86/kernel/asm-offsets_32.c | 2 +-
arch/x86/kernel/asm-offsets_64.c | 4 ++--
arch/x86/um/sys_call_table_32.c | 4 ++--
arch/x86/um/sys_call_table_64.c | 4 ++--
arch/x86/um/user-offsets.c | 4 ++--
8 files changed, 29 insertions(+), 16 deletions(-)

diff --git a/arch/x86/entry/syscall_32.c b/arch/x86/entry/syscall_32.c
index 3e2829759da2..8f895ee13a1c 100644
--- a/arch/x86/entry/syscall_32.c
+++ b/arch/x86/entry/syscall_32.c
@@ -6,11 +6,11 @@
#include <asm/asm-offsets.h>
#include <asm/syscall.h>

-#define __SYSCALL_I386(nr, sym) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long) ;
+#define __SYSCALL_I386(nr, sym, qual) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long) ;
#include <asm/syscalls_32.h>
#undef __SYSCALL_I386

-#define __SYSCALL_I386(nr, sym) [nr] = sym,
+#define __SYSCALL_I386(nr, sym, qual) [nr] = sym,

extern asmlinkage long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);

diff --git a/arch/x86/entry/syscall_64.c b/arch/x86/entry/syscall_64.c
index 3781989b180e..a1d408772ae6 100644
--- a/arch/x86/entry/syscall_64.c
+++ b/arch/x86/entry/syscall_64.c
@@ -6,11 +6,11 @@
#include <asm/asm-offsets.h>
#include <asm/syscall.h>

-#define __SYSCALL_64(nr, sym) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long) ;
+#define __SYSCALL_64(nr, sym, qual) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long) ;
#include <asm/syscalls_64.h>
#undef __SYSCALL_64

-#define __SYSCALL_64(nr, sym) [nr] = sym,
+#define __SYSCALL_64(nr, sym, qual) [nr] = sym,

extern long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);

diff --git a/arch/x86/entry/syscalls/syscalltbl.sh b/arch/x86/entry/syscalls/syscalltbl.sh
index b81479c8c5fb..cd3d3015d7df 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 @@ emit() {

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
}
diff --git a/arch/x86/kernel/asm-offsets_32.c b/arch/x86/kernel/asm-offsets_32.c
index abec4c9f1c97..fdeb0ce07c16 100644
--- a/arch/x86/kernel/asm-offsets_32.c
+++ b/arch/x86/kernel/asm-offsets_32.c
@@ -7,7 +7,7 @@
#include <linux/lguest.h>
#include "../../../drivers/lguest/lg.h"

-#define __SYSCALL_I386(nr, sym) [nr] = 1,
+#define __SYSCALL_I386(nr, sym, qual) [nr] = 1,
static char syscalls[] = {
#include <asm/syscalls_32.h>
};
diff --git a/arch/x86/kernel/asm-offsets_64.c b/arch/x86/kernel/asm-offsets_64.c
index 7d2b4d2e36b2..5de52cf589be 100644
--- a/arch/x86/kernel/asm-offsets_64.c
+++ b/arch/x86/kernel/asm-offsets_64.c
@@ -4,11 +4,11 @@

#include <asm/ia32.h>

-#define __SYSCALL_64(nr, sym) [nr] = 1,
+#define __SYSCALL_64(nr, sym, qual) [nr] = 1,
static char syscalls_64[] = {
#include <asm/syscalls_64.h>
};
-#define __SYSCALL_I386(nr, sym) [nr] = 1,
+#define __SYSCALL_I386(nr, sym, qual) [nr] = 1,
static char syscalls_ia32[] = {
#include <asm/syscalls_32.h>
};
diff --git a/arch/x86/um/sys_call_table_32.c b/arch/x86/um/sys_call_table_32.c
index d4669a679fd0..bfce503dffae 100644
--- a/arch/x86/um/sys_call_table_32.c
+++ b/arch/x86/um/sys_call_table_32.c
@@ -25,11 +25,11 @@

#define old_mmap sys_old_mmap

-#define __SYSCALL_I386(nr, sym) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long) ;
+#define __SYSCALL_I386(nr, sym, qual) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long) ;
#include <asm/syscalls_32.h>

#undef __SYSCALL_I386
-#define __SYSCALL_I386(nr, sym) [ nr ] = sym,
+#define __SYSCALL_I386(nr, sym, qual) [ nr ] = sym,

extern asmlinkage long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);

diff --git a/arch/x86/um/sys_call_table_64.c b/arch/x86/um/sys_call_table_64.c
index 6ee5268beb05..f306413d3eb6 100644
--- a/arch/x86/um/sys_call_table_64.c
+++ b/arch/x86/um/sys_call_table_64.c
@@ -35,11 +35,11 @@
#define stub_execveat sys_execveat
#define stub_rt_sigreturn sys_rt_sigreturn

-#define __SYSCALL_64(nr, sym) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long) ;
+#define __SYSCALL_64(nr, sym, qual) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long) ;
#include <asm/syscalls_64.h>

#undef __SYSCALL_64
-#define __SYSCALL_64(nr, sym) [ nr ] = sym,
+#define __SYSCALL_64(nr, sym, qual) [ nr ] = sym,

extern asmlinkage long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);

diff --git a/arch/x86/um/user-offsets.c b/arch/x86/um/user-offsets.c
index 6c9a9c1eae32..470564bbd08e 100644
--- a/arch/x86/um/user-offsets.c
+++ b/arch/x86/um/user-offsets.c
@@ -9,12 +9,12 @@
#include <asm/types.h>

#ifdef __i386__
-#define __SYSCALL_I386(nr, sym) [nr] = 1,
+#define __SYSCALL_I386(nr, sym, qual) [nr] = 1,
static char syscalls[] = {
#include <asm/syscalls_32.h>
};
#else
-#define __SYSCALL_64(nr, sym) [nr] = 1,
+#define __SYSCALL_64(nr, sym, qual) [nr] = 1,
static char syscalls[] = {
#include <asm/syscalls_64.h>
};
--
2.5.0

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