2007-11-17 05:32:05

by Ulrich Drepper

Subject: [PATCHv3 1/4] actual sys_indirect code

This is the actual architecture-independent part of the system call
implementation.

include/linux/indirect.h | 6 ++++++
include/linux/sched.h | 4 ++++
include/linux/syscalls.h | 4 ++++
kernel/Makefile | 2 +-
kernel/indirect.c | 36 ++++++++++++++++++++++++++++++++++++
5 files changed, 51 insertions(+), 1 deletion(-)

--- /dev/null
+++ include/linux/indirect.h
@@ -0,0 +1,6 @@
+#ifndef _LINUX_INDIRECT_H
+#define _LINUX_INDIRECT_H
+
+#include <asm/indirect.h>
+
+#endif
--- include/linux/sched.h
+++ include/linux/sched.h
@@ -80,6 +80,7 @@ struct sched_param {
#include <linux/rcupdate.h>
#include <linux/futex.h>
#include <linux/rtmutex.h>
+#include <linux/indirect.h>

#include <linux/time.h>
#include <linux/param.h>
@@ -1174,6 +1175,9 @@ struct task_struct {
int make_it_fail;
#endif
struct prop_local_single dirties;
+
+ /* Additional system call parameters. */
+ union indirect_params indirect_params;
};

/*
--- include/linux/syscalls.h
+++ include/linux/syscalls.h
@@ -54,6 +54,7 @@ struct compat_stat;
struct compat_timeval;
struct robust_list_head;
struct getcpu_cache;
+struct indirect_registers;

#include <linux/types.h>
#include <linux/aio_abi.h>
@@ -611,6 +612,9 @@ asmlinkage long sys_timerfd(int ufd, int clockid, int flags,
const struct itimerspec __user *utmr);
asmlinkage long sys_eventfd(unsigned int count);
asmlinkage long sys_fallocate(int fd, int mode, loff_t offset, loff_t len);
+asmlinkage long sys_indirect(struct indirect_registers __user *userregs,
+ void __user *userparams, size_t paramslen,
+ int flags);

int kernel_execve(const char *filename, char *const argv[], char *const envp[]);

--- /dev/null
+++ kernel/indirect.c
@@ -0,0 +1,36 @@
+#include <linux/sched.h>
+#include <linux/uaccess.h>
+#include <linux/unistd.h>
+#include <asm/asm-offsets.h>
+
+
+asmlinkage long sys_indirect(struct indirect_registers __user *userregs,
+ void __user *userparams, size_t paramslen,
+ int flags)
+{
+ struct indirect_registers regs;
+ long result;
+
+ if (unlikely(flags != 0))
+ return -EINVAL;
+
+ if (copy_from_user(&regs, userregs, sizeof(regs)))
+ return -EFAULT;
+
+ switch (INDIRECT_SYSCALL (&regs))
+ {
+ default:
+ return -EINVAL;
+ }
+
+ if (paramslen > sizeof(union indirect_params))
+ return -EINVAL;
+
+ result = -EFAULT;
+ if (!copy_from_user(&current->indirect_params, userparams, paramslen))
+ result = CALL_INDIRECT(&regs);
+
+ memset(&current->indirect_params, '\0', paramslen);
+
+ return result;
+}
--- kernel/Makefile
+++ kernel/Makefile
@@ -9,7 +9,7 @@ obj-y = sched.o fork.o exec_domain.o panic.o printk.o profile.o \
rcupdate.o extable.o params.o posix-timers.o \
kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o mutex.o \
hrtimer.o rwsem.o latency.o nsproxy.o srcu.o \
- utsname.o notifier.o
+ utsname.o notifier.o indirect.o

obj-$(CONFIG_SYSCTL) += sysctl_check.o
obj-$(CONFIG_STACKTRACE) += stacktrace.o