2007-11-21 07:31:07

by Ulrich Drepper

Subject: [PATCHv5 1/5] actual sys_indirect code

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

include/linux/indirect.h | 17 +++++++++++++++++
include/linux/sched.h | 4 ++++
include/linux/syscalls.h | 4 ++++
kernel/Makefile | 3 +++
kernel/indirect.c | 40 ++++++++++++++++++++++++++++++++++++++++
5 files changed, 68 insertions(+)


diff -u linux/include/linux/indirect.h linux/include/linux/indirect.h
--- linux/include/linux/indirect.h
+++ linux/include/linux/indirect.h
@@ -0,0 +1,17 @@
+#ifndef _LINUX_INDIRECT_H
+#define _LINUX_INDIRECT_H
+
+#include <asm/indirect.h>
+
+
+/* IMPORTANT:
+ All the elements of this union must be neutral to the word size
+ and must not require reworking when used in compat syscalls. Used
+ fixed-size types or types which are known to not vary in size across
+ architectures. */
+union indirect_params {
+};
+
+#define INDIRECT_PARAM(set, name) current->indirect_params.set.name
+
+#endif
diff -u linux/kernel/Makefile linux/kernel/Makefile
--- linux/kernel/Makefile
+++ linux/kernel/Makefile
@@ -57,6 +57,7 @@
obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o
obj-$(CONFIG_MARKERS) += marker.o
+obj-$(CONFIG_ARCH_HAS_INDIRECT_SYSCALLS) += indirect.o

ifneq ($(CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER),y)
# According to Alan Modra <[email protected]>, the -fno-omit-frame-pointer is
@@ -67,6 +68,8 @@
CFLAGS_sched.o := $(PROFILING) -fno-omit-frame-pointer
endif

+CFLAGS_indirect.o = -Wno-undef
+
$(obj)/configs.o: $(obj)/config_data.h

# config_data.h contains the same information as ikconfig.h but gzipped.
diff -u linux/kernel/indirect.c linux/kernel/indirect.c
--- linux/kernel/indirect.c
+++ linux/kernel/indirect.c
@@ -0,0 +1,40 @@
+#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))
+ {
+#define INDSYSCALL(name) __NR_##name
+#include <linux/indirect.h>
+ break;
+
+ 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;
+}
diff -u linux/include/linux/syscalls.h linux/include/linux/syscalls.h
--- linux/include/linux/syscalls.h
+++ linux/include/linux/syscalls.h
@@ -54,6 +54,7 @@
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 @@
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[]);

--- linux/include/linux/sched.h
+++ linux/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;
};

/*