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authorJeff Dike <jdike@addtoit.com>2008-02-04 22:31:29 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-05 09:44:32 -0800
commitf87ea91d988637b3bbf6aa2d281c6010e7d5f48d (patch)
treee93fa224b495af740537a25faa1c6d45e4a9d376
parent966f1d8f344bcec3db7d774a4ba3ab0dedfad873 (diff)
uml: redo the calculation of NR_syscalls
Redo the calculation of NR_syscalls since that disappeared from i386 and use a similar mechanism on x86_64. We now figure out the size of the system call table in arch code and stick that in syscall_table_size. arch/um/kernel/skas/syscall.c defines NR_syscalls in terms of that since its the only thing that needs to know how many system calls there are. The old mechananism that was used on x86_64 is gone. arch/um/include/sysdep-i386/syscalls.h got some formatting since I was looking at it. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: WANG Cong <xiyou.wangcong@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/um/include/sysdep-i386/syscalls.h5
-rw-r--r--arch/um/include/sysdep-x86_64/kernel-offsets.h9
-rw-r--r--arch/um/include/sysdep-x86_64/syscalls.h2
-rw-r--r--arch/um/kernel/skas/syscall.c3
-rw-r--r--arch/um/sys-i386/sys_call_table.S5
-rw-r--r--arch/um/sys-x86_64/syscall_table.c20
6 files changed, 25 insertions, 19 deletions
diff --git a/arch/um/include/sysdep-i386/syscalls.h b/arch/um/include/sysdep-i386/syscalls.h
index 57bd79efbee3..905698197e35 100644
--- a/arch/um/include/sysdep-i386/syscalls.h
+++ b/arch/um/include/sysdep-i386/syscalls.h
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
+ * Copyright (C) 2000 - 2008 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
*/
@@ -18,7 +18,8 @@ extern syscall_handler_t old_mmap_i386;
extern syscall_handler_t *sys_call_table[];
#define EXECUTE_SYSCALL(syscall, regs) \
- ((long (*)(struct syscall_args)) (*sys_call_table[syscall]))(SYSCALL_ARGS(&regs->regs))
+ ((long (*)(struct syscall_args)) \
+ (*sys_call_table[syscall]))(SYSCALL_ARGS(&regs->regs))
extern long sys_mmap2(unsigned long addr, unsigned long len,
unsigned long prot, unsigned long flags,
diff --git a/arch/um/include/sysdep-x86_64/kernel-offsets.h b/arch/um/include/sysdep-x86_64/kernel-offsets.h
index c978b589df41..a307237b7964 100644
--- a/arch/um/include/sysdep-x86_64/kernel-offsets.h
+++ b/arch/um/include/sysdep-x86_64/kernel-offsets.h
@@ -17,16 +17,7 @@
#define OFFSET(sym, str, mem) \
DEFINE(sym, offsetof(struct str, mem));
-#define __NO_STUBS 1
-#undef __SYSCALL
-#undef _ASM_X86_64_UNISTD_H_
-#define __SYSCALL(nr, sym) [nr] = 1,
-static char syscalls[] = {
-#include <asm/arch/unistd.h>
-};
-
void foo(void)
{
#include <common-offsets.h>
-DEFINE(UM_NR_syscall_max, sizeof(syscalls) - 1);
}
diff --git a/arch/um/include/sysdep-x86_64/syscalls.h b/arch/um/include/sysdep-x86_64/syscalls.h
index cf72256609e4..7cfb0b085655 100644
--- a/arch/um/include/sysdep-x86_64/syscalls.h
+++ b/arch/um/include/sysdep-x86_64/syscalls.h
@@ -30,6 +30,4 @@ extern long old_mmap(unsigned long addr, unsigned long len,
extern syscall_handler_t sys_modify_ldt;
extern syscall_handler_t sys_arch_prctl;
-#define NR_syscalls (UM_NR_syscall_max + 1)
-
#endif
diff --git a/arch/um/kernel/skas/syscall.c b/arch/um/kernel/skas/syscall.c
index 6450f024290f..4e3b820bd2be 100644
--- a/arch/um/kernel/skas/syscall.c
+++ b/arch/um/kernel/skas/syscall.c
@@ -9,6 +9,9 @@
#include "sysdep/ptrace.h"
#include "sysdep/syscalls.h"
+extern int syscall_table_size;
+#define NR_syscalls (syscall_table_size / sizeof(void *))
+
void handle_syscall(struct uml_pt_regs *r)
{
struct pt_regs *regs = container_of(r, struct pt_regs, regs);
diff --git a/arch/um/sys-i386/sys_call_table.S b/arch/um/sys-i386/sys_call_table.S
index 12d4148dba39..00e5f5203eea 100644
--- a/arch/um/sys-i386/sys_call_table.S
+++ b/arch/um/sys-i386/sys_call_table.S
@@ -9,4 +9,9 @@
#define old_mmap old_mmap_i386
+.section .rodata,"a"
+
#include "../../x86/kernel/syscall_table_32.S"
+
+ENTRY(syscall_table_size)
+.long .-sys_call_table
diff --git a/arch/um/sys-x86_64/syscall_table.c b/arch/um/sys-x86_64/syscall_table.c
index 555faee0d81f..c128eb897008 100644
--- a/arch/um/sys-x86_64/syscall_table.c
+++ b/arch/um/sys-x86_64/syscall_table.c
@@ -52,11 +52,19 @@ typedef void (*sys_call_ptr_t)(void);
extern void sys_ni_syscall(void);
-sys_call_ptr_t sys_call_table[UM_NR_syscall_max+1] __cacheline_aligned = {
- /*
- * Smells like a like a compiler bug -- it doesn't work when the &
- * below is removed.
- */
- [0 ... UM_NR_syscall_max] = &sys_ni_syscall,
+/*
+ * We used to have a trick here which made sure that holes in the
+ * x86_64 table were filled in with sys_ni_syscall, but a comment in
+ * unistd_64.h says that holes aren't allowed, so the trick was
+ * removed.
+ * The trick looked like this
+ * [0 ... UM_NR_syscall_max] = &sys_ni_syscall
+ * before including unistd_64.h - the later initializations overwrote
+ * the sys_ni_syscall filler.
+ */
+
+sys_call_ptr_t sys_call_table[] __cacheline_aligned = {
#include <asm-x86/unistd_64.h>
};
+
+int syscall_table_size = sizeof(sys_call_table);