With the use of RCU in files structure, the look-up of files using fds can now
be lock-free. The lookup is protected by rcu_read_lock()/rcu_read_unlock().
This patch changes the readers to use lock-free lookup.
Signed-off-by: Maneesh Soni <maneesh@in.ibm.com>
Signed-off-by: Ravikiran Thirumalai <kiran_th@gmail.com>
Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix sparc64 timod to use the new files_fdtable() api to get the fd table.
This is necessary for RCUification.
Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In order for the RCU to work, the file table array, sets and their sizes must
be updated atomically. Instead of ensuring this through too many memory
barriers, we put the arrays and their sizes in a separate structure. This
patch takes the first step of putting the file table elements in a separate
structure fdtable that is embedded withing files_struct. It also changes all
the users to refer to the file table using files_fdtable() macro. Subsequent
applciation of RCU becomes easier after this.
Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com>
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It appears that a memory barrier soon after a mispredicted
branch, not just in the delay slot, can cause the hang
condition of this cpu errata.
So move them out-of-line, and explicitly put them into
a "branch always, predict taken" delay slot which should
fully kill this problem.
Signed-off-by: David S. Miller <davem@davemloft.net>
From: Dave Johnson <djohnson+linux-kernel@sw.starentnetworks.com>
sendmsg()/recvmsg() syscalls from o32/n32 apps to a 64bit kernel will
cause a kernel memory leak if iov_len > UIO_FASTIOV for each syscall!
This is because both sys_sendmsg() and verify_compat_iovec() kmalloc a
new iovec structure. Only the one from sys_sendmsg() is free'ed.
I wrote a simple test program to confirm this after identifying the
problem:
http://davej.org/programs/testsendmsg.c
Note that the below fix will break solaris_sendmsg()/solaris_recvmsg() as
it also calls verify_compat_iovec() but expects it to malloc internally.
[ I fixed that. -DaveM ]
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Also fix a bug in 32-bit syscall tracing. We forgot to update
this code when we moved over to the convention that all 32-bit
syscall arguments are zero extended by default.
Signed-off-by: David S. Miller <davem@davemloft.net>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Dipankar Sarma