Index: linux-2.6.13/kernel/futex.c
===================================================================
--- linux-2.6.13.orig/kernel/futex.c
+++ linux-2.6.13/kernel/futex.c
@@ -1354,18 +1354,25 @@ static void find_owned_futex(struct vm_a
if (uaddr == 0)
continue;
+ up(&mapping->robust_sem);
+ up_read(¤t->mm->mmap_sem);
+ value = futex_get_user(uaddr);
+ if (this->futex_mutex.mutex_attr & FUTEX_ATTR_ROBUST)
+ value |= FUTEX_OWNER_DIED;
if (rt_mutex_owned_by(&this->futex_mutex, ti)) {
- up(&mapping->robust_sem);
- up_read(¤t->mm->mmap_sem);
- if (this->futex_mutex.mutex_attr & FUTEX_ATTR_ROBUST) {
- value = futex_get_user(uaddr);
- value |= FUTEX_OWNER_DIED;
- futex_put_user(value, uaddr);
- }
+ futex_put_user(value, uaddr);
up_futex(&this->futex_mutex);
- down(&mapping->robust_sem);
- down_read(¤t->mm->mmap_sem);
+ } else if ((value & FUTEX_PID) == current->pid) {
+ /*
+ * this bit is for the fast path. If the lock is only
+ * locked in user space wee need to unlock it
+ * for the exiting thread.
+ */
+ value &= ~FUTEX_PID;
+ futex_put_user(value, uaddr);
}
+ down(&mapping->robust_sem);
+ down_read(¤t->mm->mmap_sem);
}
up(&mapping->robust_sem);
@@ -1524,7 +1531,7 @@ static int futex_deregister(unsigned lon
if (rt_mutex_owned_by(&this->futex_mutex, ti)) {
up_futex(&this->futex_mutex);
} else if (rt_mutex_owner(&this->futex_mutex) != NULL) {
- ret = -EINVAL;
+ ret = -EBUSY;
break;
}
list_del(&this->list);
Index: linux-2.6.13/include/linux/futex.h
===================================================================
--- linux-2.6.13.orig/include/linux/futex.h
+++ linux-2.6.13/include/linux/futex.h
@@ -1,8 +1,6 @@
#ifndef _LINUX_FUTEX_H
#define _LINUX_FUTEX_H
-#include <linux/fs.h>
-
/* Second argument to futex syscall */
Index: linux-2.6.13/kernel/rt.c
===================================================================
--- linux-2.6.13.orig/kernel/rt.c
+++ linux-2.6.13/kernel/rt.c
@@ -47,6 +47,7 @@
#include <linux/syscalls.h>
#include <linux/interrupt.h>
#include <linux/plist.h>
+#include <linux/fs.h>
#include <linux/futex.h>
#define CAPTURE_LOCK
* David Singleton <[email protected]> wrote:
> Ingo,
> here 's a patch for 2.6.14-rc4-rt1 that fixes two things:
>
> 1) Deregister futex returns -EBUSY instead of -EINVAL if a thread
> tries to deregister a pthread_mutex that another thread has locked.
>
> 2) Make the fast path robust. If a pthread_mutex is only locked in
> user space we need to clear the owner when the thread dies. This
> makes both the 'rt_mutex is locked in the kernel' and the
> 'pthread_mutex is only locked in user space' paths robust.
thanks, applied.
Ingo
* David Singleton <[email protected]> wrote:
> Index: linux-2.6.13/include/linux/futex.h
> ===================================================================
> --- linux-2.6.13.orig/include/linux/futex.h
> +++ linux-2.6.13/include/linux/futex.h
> @@ -1,8 +1,6 @@
> #ifndef _LINUX_FUTEX_H
> #define _LINUX_FUTEX_H
>
> -#include <linux/fs.h>
> -
> /* Second argument to futex syscall */
>
this chunk broke the build, so i added the #include back. Really, the
robust mutex glibc patches should _NOT_ automatically include the
kernel's futex.h file. If they do so and rely on an installed
kernel-headers package then they are broken. Just copy the file into the
glibc tree and remove the #include line.
Ingo
Hi Ingo
As we pass same flags from glibc to kernel we thought it will be good to
have defines in one place to avoid going out of sync in future.
glibc already has dependency on kernel headers. So were looking for ways
to fix futex.h in kernel so that glibc can use it. But if it is not
feasible then we can define these flags inside glibc headers. Only
additional burden will be that these headers will be required to be
synced whenever there is any change pertaining to them(mostly the defines.)
Thanks
Khem
Ingo Molnar wrote:
>* David Singleton <[email protected]> wrote:
>
>
>
>>Index: linux-2.6.13/include/linux/futex.h
>>===================================================================
>>--- linux-2.6.13.orig/include/linux/futex.h
>>+++ linux-2.6.13/include/linux/futex.h
>>@@ -1,8 +1,6 @@
>> #ifndef _LINUX_FUTEX_H
>> #define _LINUX_FUTEX_H
>>
>>-#include <linux/fs.h>
>>-
>> /* Second argument to futex syscall */
>>
>>
>>
>
>this chunk broke the build, so i added the #include back. Really, the
>robust mutex glibc patches should _NOT_ automatically include the
>kernel's futex.h file. If they do so and rely on an installed
>kernel-headers package then they are broken. Just copy the file into the
>glibc tree and remove the #include line.
>
> Ingo
>
>
>------------------------------------------------------------------------
>
>_______________________________________________
>robustmutexes mailing list
>[email protected]
>https://lists.osdl.org/mailman/listinfo/robustmutexes
>
>
--
Khem Raj <[email protected]>
MontaVista Software, Inc.
http://www.mvista.com