[PATCH v2 05/10] x86/syscalls: Move compat syscall entry handling into syscalltbl.sh

From: Andy Lutomirski
Date: Thu Jan 28 2016 - 18:14:00 EST


Rather than duplicating the compat entry handling in all consumers
of syscalls_BITS.h, handle it directly in syscalltbl.sh. Now we
generate entries in syscalls_32.h like:

__SYSCALL_I386(5, sys_open)
__SYSCALL_I386(5, compat_sys_open)

and all of its consumers implicitly get the right entry point.

Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
---
arch/x86/entry/syscall_32.c | 10 ++--------
arch/x86/entry/syscall_64.c | 4 ++--
arch/x86/entry/syscalls/syscalltbl.sh | 22 ++++++++++++++++++----
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, 31 insertions(+), 23 deletions(-)

diff --git a/arch/x86/entry/syscall_32.c b/arch/x86/entry/syscall_32.c
index 9a6649857106..3e2829759da2 100644
--- a/arch/x86/entry/syscall_32.c
+++ b/arch/x86/entry/syscall_32.c
@@ -6,17 +6,11 @@
#include <asm/asm-offsets.h>
#include <asm/syscall.h>

-#ifdef CONFIG_IA32_EMULATION
-#define SYM(sym, compat) compat
-#else
-#define SYM(sym, compat) sym
-#endif
-
-#define __SYSCALL_I386(nr, sym, compat) extern asmlinkage long SYM(sym, compat)(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long) ;
+#define __SYSCALL_I386(nr, sym) 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, compat) [nr] = SYM(sym, compat),
+#define __SYSCALL_I386(nr, sym) [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 974fd89ac806..3781989b180e 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, compat) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long) ;
+#define __SYSCALL_64(nr, sym) 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, compat) [nr] = sym,
+#define __SYSCALL_64(nr, sym) [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 5ebeaf1041e7..b81479c8c5fb 100644
--- a/arch/x86/entry/syscalls/syscalltbl.sh
+++ b/arch/x86/entry/syscalls/syscalltbl.sh
@@ -8,10 +8,24 @@ emit() {
nr="$2"
entry="$3"
compat="$4"
- if [ -n "$compat" ]; then
- echo "__SYSCALL_${abi}($nr, $entry, $compat)"
- elif [ -n "$entry" ]; then
- echo "__SYSCALL_${abi}($nr, $entry, $entry)"
+
+ if [ "$abi" == "64" -a -n "$compat" ]; then
+ echo "a compat entry for a 64-bit syscall makes no sense" >&2
+ exit 1
+ fi
+
+ if [ -z "$compat" ]; then
+ if [ -n "$entry" ]; then
+ echo "__SYSCALL_${abi}($nr, $entry)"
+ fi
+ else
+ echo "#ifdef CONFIG_X86_32"
+ if [ -n "$entry" ]; then
+ echo "__SYSCALL_${abi}($nr, $entry)"
+ fi
+ echo "#else"
+ echo "__SYSCALL_${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 6ce39025f467..abec4c9f1c97 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, compat) [nr] = 1,
+#define __SYSCALL_I386(nr, sym) [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 29db3b3f550c..9677bf9a616f 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, compat) [nr] = 1,
+#define __SYSCALL_64(nr, sym) [nr] = 1,
static char syscalls_64[] = {
#include <asm/syscalls_64.h>
};
-#define __SYSCALL_I386(nr, sym, compat) [nr] = 1,
+#define __SYSCALL_I386(nr, sym) [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 439c0994b696..d4669a679fd0 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, compat) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long) ;
+#define __SYSCALL_I386(nr, sym) 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, compat) [ nr ] = sym,
+#define __SYSCALL_I386(nr, sym) [ 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 71a497cde921..6ee5268beb05 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, compat) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long) ;
+#define __SYSCALL_64(nr, sym) 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, compat) [ nr ] = sym,
+#define __SYSCALL_64(nr, sym) [ 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 5edf4f4bbf53..6c9a9c1eae32 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, compat) [nr] = 1,
+#define __SYSCALL_I386(nr, sym) [nr] = 1,
static char syscalls[] = {
#include <asm/syscalls_32.h>
};
#else
-#define __SYSCALL_64(nr, sym, compat) [nr] = 1,
+#define __SYSCALL_64(nr, sym) [nr] = 1,
static char syscalls[] = {
#include <asm/syscalls_64.h>
};
--
2.5.0