From f87ea91d988637b3bbf6aa2d281c6010e7d5f48d Mon Sep 17 00:00:00 2001 From: Jeff Dike Date: Mon, 4 Feb 2008 22:31:29 -0800 Subject: [PATCH] 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 Cc: WANG Cong Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/um/include/sysdep-i386/syscalls.h | 5 +++-- .../um/include/sysdep-x86_64/kernel-offsets.h | 9 --------- arch/um/include/sysdep-x86_64/syscalls.h | 2 -- arch/um/kernel/skas/syscall.c | 3 +++ arch/um/sys-i386/sys_call_table.S | 5 +++++ arch/um/sys-x86_64/syscall_table.c | 20 +++++++++++++------ 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(®s->regs)) + ((long (*)(struct syscall_args)) \ + (*sys_call_table[syscall]))(SYSCALL_ARGS(®s->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 -}; - void foo(void) { #include -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 }; + +int syscall_table_size = sizeof(sys_call_table); -- GitLab