Question

我遇到麻烦了，我不知道发生了什么。使用SYSCALL_DEFINE时，我无法添加syscall。每个构建都去： ld: arch/x86/entry/syscall_32.o:(.rodata+0xc18): undefined reference to 'sys_get_pid_info' 同样适用于64版本

当我做一个普通的原型时，代码实际上正在编译和运行： asmlinkage long get_pid_info(void)

但是如果我正在使用：SYSCALL_DEFINE0(get_pid_info)

这是4.19版本的Master分支中diff的补丁。

diff --git a/Makefile b/Makefile
index 7a2a9a175756..fe78cd54b7ef 100644
--- a/Makefile
+++ b/Makefile
@@ -970,6 +970,7 @@ endif
 ifeq ($(KBUILD_EXTMOD),)
 core-y         += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
+core-y         += get_pid_info/
 vmlinux-dirs   := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
                     $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index 3cf7b533b3d1..08e6569134d6 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -398,3 +398,4 @@
 384    i386    arch_prctl              sys_arch_prctl                  __ia32_compat_sys_arch_prctl
 385    i386    io_pgetevents           sys_io_pgetevents               __ia32_compat_sys_io_pgetevents
 386    i386    rseq                    sys_rseq                        __ia32_sys_rseq
+387    i386    get_pid_info    sys_get_pid_info
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index f0b1709a5ffb..da6c9d0f0c01 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -343,6 +343,7 @@
 332    common  statx                   __x64_sys_statx
 333    common  io_pgetevents           __x64_sys_io_pgetevents
 334    common  rseq                    __x64_sys_rseq
+335    common  get_pid_info            sys_get_pid_info
 #
 # x32-specific system call numbers start at 512 to avoid cache impact
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 2ac3d13a915b..a0bff632b8fa 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -1296,4 +1296,7 @@ static inline unsigned int ksys_personality(unsigned int personality)
        return old;
 }
+
+asmlinkage long        sys_get_pid_info(void);
+
 #endif

注意：使用普通的protorype，我不需要将其添加到include/linux/syscalls.h

这是我的C Syscall函数：

#include <linux/kernel.h>
#include <linux/syscalls.h>
//asmlinkage long get_pid_info(void) <-- works with it
SYSCALL_DEFINE0(get_pid_info)
{
        printk("Hello world !\n");
        return 0;
}

现在这是构建的输出（包括我的syscall编译后打印的内容）

[...]
  CC      get_pid_info/get_pid_info.o
  AR      get_pid_info/built-in.a  
[...]
  LD      vmlinux.o
  MODPOST vmlinux.o
ld: arch/x86/entry/syscall_64.o:(.rodata+0xa78): undefined reference to `sys_get_pid_info'
ld: arch/x86/entry/syscall_32.o:(.rodata+0xc18): undefined reference to `sys_get_pid_info'
make: *** [Makefile:1036: vmlinux] Error 1

感谢您的帮助！我认为这并不难，但是我被困在这里。最好的问候，巴斯蒂安

使用SYSCALL_DEFINE时对syscall的未定义引用

0 个答案: