Messages in this thread Patch in this message | | | Date | Fri, 22 Feb 2008 16:31:11 -0800 | From | Greg KH <> | Subject | [patch 26/38] hrtimer: fix *rmtp/restarts handling in compat_sys_nanosleep() |
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2.6.24-stable review patch. If anyone has any objections, please let us know.
------------------ From: Oleg Nesterov <oleg@tv-sign.ru>
commit 416529374b4793ba2d2e97e736d108a2e0f3ef07
Spotted by Pavel Emelyanov and Alexey Dobriyan.
compat_sys_nanosleep() implicitly uses hrtimer_nanosleep_restart(), this can't work. Make a suitable compat_nanosleep_restart() helper.
Introduced by commit c70878b4e0b6cf8d2f1e46319e48e821ef4a8aba hrtimer: hook compat_sys_nanosleep up to high res timer code
Also, set ->addr_limit = KERNEL_DS before doing hrtimer_nanosleep(), this func was changed by the previous patch and now takes the "__user *" parameter.
Thanks to Ingo Molnar for fixing the bug in this patch.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Alexey Dobriyan <adobriyan@sw.ru> Cc: Pavel Emelyanov <xemul@sw.ru> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Toyo Abe <toyoa@mvista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- kernel/compat.c | 44 ++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 40 insertions(+), 4 deletions(-)
--- a/kernel/compat.c +++ b/kernel/compat.c @@ -40,10 +40,36 @@ int put_compat_timespec(const struct tim __put_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0; } +static long compat_nanosleep_restart(struct restart_block *restart) +{ + struct compat_timespec __user *rmtp; + struct timespec rmt; + mm_segment_t oldfs; + long ret; + + rmtp = (struct compat_timespec __user *)(restart->arg1); + restart->arg1 = (unsigned long)&rmt; + oldfs = get_fs(); + set_fs(KERNEL_DS); + ret = hrtimer_nanosleep_restart(restart); + set_fs(oldfs); + + if (ret) { + restart->fn = compat_nanosleep_restart; + restart->arg1 = (unsigned long)rmtp; + + if (rmtp && put_compat_timespec(&rmt, rmtp)) + return -EFAULT; + } + + return ret; +} + asmlinkage long compat_sys_nanosleep(struct compat_timespec __user *rqtp, struct compat_timespec __user *rmtp) { struct timespec tu, rmt; + mm_segment_t oldfs; long ret; if (get_compat_timespec(&tu, rqtp)) @@ -52,11 +78,21 @@ asmlinkage long compat_sys_nanosleep(str if (!timespec_valid(&tu)) return -EINVAL; - ret = hrtimer_nanosleep(&tu, rmtp ? &rmt : NULL, HRTIMER_MODE_REL, - CLOCK_MONOTONIC); + oldfs = get_fs(); + set_fs(KERNEL_DS); + ret = hrtimer_nanosleep(&tu, + rmtp ? (struct timespec __user *)&rmt : NULL, + HRTIMER_MODE_REL, CLOCK_MONOTONIC); + set_fs(oldfs); + + if (ret) { + struct restart_block *restart + = ¤t_thread_info()->restart_block; + + restart->fn = compat_nanosleep_restart; + restart->arg1 = (unsigned long)rmtp; - if (ret && rmtp) { - if (put_compat_timespec(&rmt, rmtp)) + if (rmtp && put_compat_timespec(&rmt, rmtp)) return -EFAULT; } --
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