Stephen Rothwell wrote:
>
> Hi Linus,
>
> Below is the generic part of the start of the compatibility syscall layer.
> I think I have made it generic enough that each architecture can define
> what compatibility means.
>
> To use this,an architecture must create asm/compat.h and provide typedefs
> for (currently) compat_time_t, compat_suseconds_t, struct compat_timespec.
>
> Hopefully, this is what you had in mind - ohterwise back to the drawing
> board.
>
> I will follow this posting with the architecture specific patches that I
> have done but not tested.
The standard for POSIX nano_sleep() says that it should not
return on a signal UNLESS the signal is delivered to the
user. (I.e. not on SIGSTOP, SIGTRACE, etc. or any signal
that does not invoke a user handler.) To do this sort of
thing the do_signal() function returns true in this case and
otherwise false. The reason this is not in nano_sleep()
today seems to be that do_signal() requires ®s which
differs from arch to arch in how it is passed to a system
call handler. The common code does not need or use regs
except to pass it to do_signal().
As a suggestion for a solution for this, is it true that
regs, on a system call, will ALWAYS be at the end of the
stack? Lets assume, at least for nano_sleep, that it will
not be called from the kernel. Even if it is, what should
signal behavior be in this case? Should it not use the user
regs?
Here is a suggested function to get the regs:
struct pt_regs *get_task_registers(struct task_struct* task)
{
return (struct pt_regs *)((unsigned char
*)task->thread.esp0 -
sizeof(struct pt_regs));
}
comments?
>
> --
> Cheers,
> Stephen Rothwell sfr@canb.auug.org.au
> http://www.canb.auug.org.au/~sfr/
>
> diff -ruN 2.5.50-BK.2/fs/open.c 2.5.50-BK.2-32bit.1/fs/open.c
> --- 2.5.50-BK.2/fs/open.c 2002-12-04 12:07:36.000000000 +1100
> +++ 2.5.50-BK.2-32bit.1/fs/open.c 2002-12-04 12:01:36.000000000 +1100
> @@ -280,7 +280,7 @@
> * must be owner or have write permission.
> * Else, update from *times, must be owner or super user.
> */
> -asmlinkage long sys_utimes(char * filename, struct timeval * utimes)
> +long do_utimes(char * filename, struct timeval * times)
> {
> int error;
> struct nameidata nd;
> @@ -299,11 +299,7 @@
>
> /* Don't worry, the checks are done in inode_change_ok() */
> newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME;
> - if (utimes) {
> - struct timeval times[2];
> - error = -EFAULT;
> - if (copy_from_user(×, utimes, sizeof(times)))
> - goto dput_and_out;
> + if (times) {
> newattrs.ia_atime.tv_sec = times[0].tv_sec;
> newattrs.ia_atime.tv_nsec = times[0].tv_usec * 1000;
> newattrs.ia_mtime.tv_sec = times[1].tv_sec;
> @@ -323,6 +319,16 @@
> return error;
> }
>
> +asmlinkage long sys_utimes(char * filename, struct timeval * utimes)
> +{
> + struct timeval times[2];
> +
> + if (utimes && copy_from_user(×, utimes, sizeof(times)))
> + return -EFAULT;
> + return do_utimes(filename, utimes ? times : NULL);
> +}
> +
> +
> /*
> * access() needs to use the real uid/gid, not the effective uid/gid.
> * We do this by temporarily clearing all FS-related capabilities and
> diff -ruN 2.5.50-BK.2/include/linux/compat.h 2.5.50-BK.2-32bit.1/include/linux/compat.h
> --- 2.5.50-BK.2/include/linux/compat.h 1970-01-01 10:00:00.000000000 +1000
> +++ 2.5.50-BK.2-32bit.1/include/linux/compat.h 2002-12-04 15:42:36.000000000 +1100
> @@ -0,0 +1,29 @@
> +#ifndef _LINUX_COMPAT_H
> +#define _LINUX_COMPAT_H
> +/*
> + * These are the type definitions for the arhitecure sepcific
> + * compatibility layer.
> + */
> +#include <linux/config.h>
> +
> +#ifdef CONFIG_COMPAT
> +
> +#include <asm/compat.h>
> +
> +struct compat_timeval {
> + compat_time_t tv_sec;
> + compat_suseconds_t tv_usec;
> +};
> +
> +struct compat_utimbuf {
> + compat_time_t actime;
> + compat_time_t modtime;
> +};
> +
> +struct compat_itimerval {
> + struct compat_timeval it_interval;
> + struct compat_timeval it_value;
> +};
> +
> +#endif /* CONFIG_COMPAT */
> +#endif /* _LINUX_COMPAT_H */
> diff -ruN 2.5.50-BK.2/include/linux/time.h 2.5.50-BK.2-32bit.1/include/linux/time.h
> --- 2.5.50-BK.2/include/linux/time.h 2002-11-18 15:47:56.000000000 +1100
> +++ 2.5.50-BK.2-32bit.1/include/linux/time.h 2002-12-03 15:47:26.000000000 +1100
> @@ -138,6 +138,8 @@
> #ifdef __KERNEL__
> extern void do_gettimeofday(struct timeval *tv);
> extern void do_settimeofday(struct timeval *tv);
> +extern long do_nanosleep(struct timespec *t);
> +extern long do_utimes(char * filename, struct timeval * times);
> #endif
>
> #define FD_SETSIZE __FD_SETSIZE
> diff -ruN 2.5.50-BK.2/kernel/Makefile 2.5.50-BK.2-32bit.1/kernel/Makefile
> --- 2.5.50-BK.2/kernel/Makefile 2002-11-28 10:34:59.000000000 +1100
> +++ 2.5.50-BK.2-32bit.1/kernel/Makefile 2002-12-03 15:42:28.000000000 +1100
> @@ -21,6 +21,7 @@
> obj-$(CONFIG_CPU_FREQ) += cpufreq.o
> obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o
> obj-$(CONFIG_SOFTWARE_SUSPEND) += suspend.o
> +obj-$(CONFIG_COMPAT) += compat.o
>
> ifneq ($(CONFIG_IA64),y)
> # According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is
> diff -ruN 2.5.50-BK.2/kernel/compat.c 2.5.50-BK.2-32bit.1/kernel/compat.c
> --- 2.5.50-BK.2/kernel/compat.c 1970-01-01 10:00:00.000000000 +1000
> +++ 2.5.50-BK.2-32bit.1/kernel/compat.c 2002-12-04 17:40:08.000000000 +1100
> @@ -0,0 +1,114 @@
> +/*
> + * linux/kernel/compat.c
> + *
> + * Kernel compatibililty routines for e.g. 32 bit syscall support
> + * on 64 bit kernels.
> + *
> + * Copyright (C) 2002 Stephen Rothwell, IBM Corporation
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/linkage.h>
> +#include <linux/compat.h>
> +#include <linux/errno.h>
> +#include <linux/time.h>
> +
> +#include <asm/uaccess.h>
> +
> +asmlinkage long compat_sys_nanosleep(struct compat_timespec *rqtp,
> + struct compat_timespec *rmtp)
> +{
> + struct timespec t;
> + struct compat_timespec ct;
> + s32 ret;
> +
> + if (copy_from_user(&ct, rqtp, sizeof(ct)))
> + return -EFAULT;
> + t.tv_sec = ct.tv_sec;
> + t.tv_nsec = ct.tv_nsec;
> + ret = do_nanosleep(&t);
> + if (rmtp && (ret == -EINTR)) {
> + ct.tv_sec = t.tv_sec;
> + ct.tv_nsec = t.tv_nsec;
> + if (copy_to_user(rmtp, &ct, sizeof(ct)))
> + return -EFAULT;
> + }
> + return ret;
> +}
> +
> +/*
> + * Not all architectures have sys_utime, so implement this in terms
> + * of sys_utimes.
> + */
> +asmlinkage long compat_sys_utime(char *filename, struct compat_utimbuf *t)
> +{
> + struct timeval tv[2];
> +
> + if (t) {
> + if (get_user(tv[0].tv_sec, &t->actime) ||
> + get_user(tv[1].tv_sec, &t->modtime))
> + return -EFAULT;
> + tv[0].tv_usec = 0;
> + tv[1].tv_usec = 0;
> + }
> + return do_utimes(filename, t ? tv : NULL);
> +}
> +
> +
> +static inline long get_compat_itimerval(struct itimerval *o,
> + struct compat_itimerval *i)
> +{
> + return (!access_ok(VERIFY_READ, i, sizeof(*i)) ||
> + (__get_user(o->it_interval.tv_sec, &i->it_interval.tv_sec) |
> + __get_user(o->it_interval.tv_usec, &i->it_interval.tv_usec) |
> + __get_user(o->it_value.tv_sec, &i->it_value.tv_sec) |
> + __get_user(o->it_value.tv_usec, &i->it_value.tv_usec)));
> +}
> +
> +static inline long put_compat_itimerval(struct compat_itimerval *o,
> + struct itimerval *i)
> +{
> + return (!access_ok(VERIFY_WRITE, o, sizeof(*o)) ||
> + (__put_user(i->it_interval.tv_sec, &o->it_interval.tv_sec) |
> + __put_user(i->it_interval.tv_usec, &o->it_interval.tv_usec) |
> + __put_user(i->it_value.tv_sec, &o->it_value.tv_sec) |
> + __put_user(i->it_value.tv_usec, &o->it_value.tv_usec)));
> +}
> +
> +extern int do_getitimer(int which, struct itimerval *value);
> +
> +asmlinkage long compat_sys_getitimer(int which, struct compat_itimerval *it)
> +{
> + struct itimerval kit;
> + int error;
> +
> + error = do_getitimer(which, &kit);
> + if (!error && put_compat_itimerval(it, &kit))
> + error = -EFAULT;
> + return error;
> +}
> +
> +extern int do_setitimer(int which, struct itimerval *, struct itimerval *);
> +
> +asmlinkage long compat_sys_setitimer(int which, struct compat_itimerval *in,
> + struct compat_itimerval *out)
> +{
> + struct itimerval kin, kout;
> + int error;
> +
> + if (in) {
> + if (get_compat_itimerval(&kin, in))
> + return -EFAULT;
> + } else
> + memset(&kin, 0, sizeof(kin));
> +
> + error = do_setitimer(which, &kin, out ? &kout : NULL);
> + if (error || !out)
> + return error;
> + if (put_compat_itimerval(out, &kout))
> + return -EFAULT;
> + return 0;
> +}
> diff -ruN 2.5.50-BK.2/kernel/timer.c 2.5.50-BK.2-32bit.1/kernel/timer.c
> --- 2.5.50-BK.2/kernel/timer.c 2002-12-04 12:07:39.000000000 +1100
> +++ 2.5.50-BK.2-32bit.1/kernel/timer.c 2002-12-04 12:03:23.000000000 +1100
> @@ -1020,33 +1020,41 @@
> return current->pid;
> }
>
> -asmlinkage long sys_nanosleep(struct timespec *rqtp, struct timespec *rmtp)
> +long do_nanosleep(struct timespec *t)
> {
> - struct timespec t;
> unsigned long expire;
>
> - if(copy_from_user(&t, rqtp, sizeof(struct timespec)))
> - return -EFAULT;
> -
> - if (t.tv_nsec >= 1000000000L || t.tv_nsec < 0 || t.tv_sec < 0)
> + if ((t->tv_nsec >= 1000000000L) || (t->tv_nsec < 0) || (t->tv_sec < 0))
> return -EINVAL;
>
> - expire = timespec_to_jiffies(&t) + (t.tv_sec || t.tv_nsec);
> + expire = timespec_to_jiffies(t) + (t->tv_sec || t->tv_nsec);
>
> current->state = TASK_INTERRUPTIBLE;
> expire = schedule_timeout(expire);
>
> if (expire) {
> - if (rmtp) {
> - jiffies_to_timespec(expire, &t);
> - if (copy_to_user(rmtp, &t, sizeof(struct timespec)))
> - return -EFAULT;
> - }
> + jiffies_to_timespec(expire, t);
> return -EINTR;
> }
> return 0;
> }
>
> +asmlinkage long sys_nanosleep(struct timespec *rqtp, struct timespec *rmtp)
> +{
> + struct timespec t;
> + long ret;
> +
> + if (copy_from_user(&t, rqtp, sizeof(t)))
> + return -EFAULT;
> +
> + ret = do_nanosleep(&t);
> + if (rmtp && (ret == -EINTR)) {
> + if (copy_to_user(rmtp, &t, sizeof(t)))
> + return -EFAULT;
> + }
> + return ret;
> +}
> +
> /*
> * sys_sysinfo - fill in sysinfo struct
> */
> -
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-- George Anzinger george@mvista.com High-res-timers: http://sourceforge.net/projects/high-res-timers/ Preemption patch: http://www.kernel.org/pub/linux/kernel/people/rml - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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