09 May, 2007
40 commits
-
This patch moves the die notifier handling to common code. Previous
various architectures had exactly the same code for it. Note that the new
code is compiled unconditionally, this should be understood as an appel to
the other architecture maintainer to implement support for it aswell (aka
sprinkling a notify_die or two in the proper place)arm had a notifiy_die that did something totally different, I renamed it to
arm_notify_die as part of the patch and made it static to the file it's
declared and used at. avr32 used to pass slightly less information through
this interface and I brought it into line with the other architectures.[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix vmalloc_sync_all bustage]
[bryan.wu@analog.com: fix vmalloc_sync_all in nommu]
Signed-off-by: Christoph Hellwig
Cc:
Cc: Russell King
Signed-off-by: Bryan Wu
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fix sparse NULL warnings:
kernel/kprobes.c:915:49: warning: Using plain integer as NULL pointerSigned-off-by: Randy Dunlap
Acked-by: Ananth N Mavinakayanahalli
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
REISER_FS /proc option needs to depend on PROC_FS.
fs/reiserfs/procfs.c: In function 'show_super':
fs/reiserfs/procfs.c:134: error: 'reiserfs_proc_info_data_t' has no member named 'max_hash_collisions'
fs/reiserfs/procfs.c:134: error: 'reiserfs_proc_info_data_t' has no member named 'breads'
fs/reiserfs/procfs.c:135: error: 'reiserfs_proc_info_data_t' has no member named 'bread_miss'
fs/reiserfs/procfs.c:135: error: 'reiserfs_proc_info_data_t' has no member named 'search_by_key'
fs/reiserfs/procfs.c:136: error: 'reiserfs_proc_info_data_t' has no member named 'search_by_key_fs_changed'
fs/reiserfs/procfs.c:136: error: 'reiserfs_proc_info_data_t' has no member named 'search_by_key_restarted'
fs/reiserfs/procfs.c:137: error: 'reiserfs_proc_info_data_t' has no member named 'insert_item_restarted'
fs/reiserfs/procfs.c:137: error: 'reiserfs_proc_info_data_t' has no member named 'paste_into_item_restarted'
fs/reiserfs/procfs.c:138: error: 'reiserfs_proc_info_data_t' has no member named 'cut_from_item_restarted'
fs/reiserfs/procfs.c:139: error: 'reiserfs_proc_info_data_t' has no member named 'delete_solid_item_restarted'
fs/reiserfs/procfs.c:139: error: 'reiserfs_proc_info_data_t' has no member named 'delete_item_restarted'
fs/reiserfs/procfs.c:140: error: 'reiserfs_proc_info_data_t' has no member named 'leaked_oid'
fs/reiserfs/procfs.c:140: error: 'reiserfs_proc_info_data_t' has no member named 'leaves_removable'
fs/reiserfs/procfs.c: In function 'show_per_level':
fs/reiserfs/procfs.c:184: error: 'reiserfs_proc_info_data_t' has no member named 'balance_at'
fs/reiserfs/procfs.c:185: error: 'reiserfs_proc_info_data_t' has no member named 'sbk_read_at'
fs/reiserfs/procfs.c:186: error: 'reiserfs_proc_info_data_t' has no member named 'sbk_fs_changed'
fs/reiserfs/procfs.c:187: error: 'reiserfs_proc_info_data_t' has no member named 'sbk_restarted'
fs/reiserfs/procfs.c:188: error: 'reiserfs_proc_info_data_t' has no member named 'free_at'
fs/reiserfs/procfs.c:189: error: 'reiserfs_proc_info_data_t' has no member named 'items_at'
fs/reiserfs/procfs.c:190: error: 'reiserfs_proc_info_data_t' has no member named 'can_node_be_removed'
fs/reiserfs/procfs.c:191: error: 'reiserfs_proc_info_data_t' has no member named 'lnum'
fs/reiserfs/procfs.c:192: error: 'reiserfs_proc_info_data_t' has no member named 'rnum'
fs/reiserfs/procfs.c:193: error: 'reiserfs_proc_info_data_t' has no member named 'lbytes'
fs/reiserfs/procfs.c:194: error: 'reiserfs_proc_info_data_t' has no member named 'rbytes'
fs/reiserfs/procfs.c:195: error: 'reiserfs_proc_info_data_t' has no member named 'get_neighbors'
fs/reiserfs/procfs.c:196: error: 'reiserfs_proc_info_data_t' has no member named 'get_neighbors_restart'
fs/reiserfs/procfs.c:197: error: 'reiserfs_proc_info_data_t' has no member named 'need_l_neighbor'
fs/reiserfs/procfs.c:197: error: 'reiserfs_proc_info_data_t' has no member named 'need_r_neighbor'
fs/reiserfs/procfs.c: In function 'show_bitmap':
fs/reiserfs/procfs.c:224: error: 'reiserfs_proc_info_data_t' has no member named 'free_block'
fs/reiserfs/procfs.c:225: error: 'reiserfs_proc_info_data_t' has no member named 'scan_bitmap'
fs/reiserfs/procfs.c:226: error: 'reiserfs_proc_info_data_t' has no member named 'scan_bitmap'
fs/reiserfs/procfs.c:227: error: 'reiserfs_proc_info_data_t' has no member named 'scan_bitmap'
fs/reiserfs/procfs.c:228: error: 'reiserfs_proc_info_data_t' has no member named 'scan_bitmap'
fs/reiserfs/procfs.c:229: error: 'reiserfs_proc_info_data_t' has no member named 'scan_bitmap'
fs/reiserfs/procfs.c:230: error: 'reiserfs_proc_info_data_t' has no member named 'scan_bitmap'
fs/reiserfs/procfs.c:230: error: 'reiserfs_proc_info_data_t' has no member named 'scan_bitmap'
fs/reiserfs/procfs.c: In function 'show_journal':
fs/reiserfs/procfs.c:384: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:385: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:386: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:387: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:388: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:389: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:390: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:391: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:392: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:393: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:394: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:395: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:395: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c:395: error: 'reiserfs_proc_info_data_t' has no member named 'journal'
fs/reiserfs/procfs.c: In function 'reiserfs_proc_info_init':
fs/reiserfs/procfs.c:504: warning: implicit declaration of function '__PINFO'
fs/reiserfs/procfs.c:504: error: request for member 'lock' in something not a structure or union
fs/reiserfs/procfs.c: In function 'reiserfs_proc_info_done':
fs/reiserfs/procfs.c:544: error: request for member 'lock' in something not a structure or union
fs/reiserfs/procfs.c:545: error: request for member 'exiting' in something not a structure or union
fs/reiserfs/procfs.c:546: error: request for member 'lock' in something not a structure or unionSigned-off-by: Randy Dunlap
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
While researching the tty layer pid leaks I found a weird case in selinux when
we drop a controlling tty because of inadequate permissions we don't do the
normal hangup processing. Which is a problem if it happens the session leader
has exec'd something that can no longer access the tty.We already have code in the kernel to handle this case in the form of the
TIOCNOTTY ioctl. So this patch factors out a helper function that is the
essence of that ioctl and calls it from the selinux code.This removes the inconsistency in handling dropping of a controlling tty and
who knows it might even make some part of user space happy because it received
a SIGHUP it was expecting.In addition since this removes the last user of proc_set_tty outside of
tty_io.c proc_set_tty is made static and removed from tty.hSigned-off-by: Eric W. Biederman
Acked-by: Alan Cox
Cc: James Morris
Cc: Stephen Smalley
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch should contain no functional changes.
At some point I got confused and thought put_pid could not be called while a
spin lock was held. While it may be nice to avoid that to reduce lock hold
times put_pid can be safely called while we hold a spin lock.This patch removes all of the complications from the code introduced by my
misunderstanding, making the code a little more readable.Signed-off-by: Eric W. Biederman
Cc: Alan Cox
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
All of the users of proc_clear_tty are compiled into the kernel so exporting
this symbol appears gratuitous.Signed-off-by: Eric W. Biederman
Cc: Alan Cox
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The console subsystem already has an idea of a boot console, using the
CON_BOOT flag. The implementation has some flaws though. The major
problem is that presence of a boot console makes register_console() ignore
any other console devices (unless explicitly specified on the kernel
command line).This patch fixes the console selection code to *not* consider a boot
console a full-featured one, so the first non-boot console registering will
become the default console instead. This way the unregister call for the
boot console in the register_console() function actually triggers and the
handover from the boot console to the real console device works smoothly.
Added a printk for the handover, so you know which console device the
output goes to when the boot console stops printing messages.The disable_early_printk() call is obsolete with that patch, explicitly
disabling the early console isn't needed any more as it works automagically
with that patch.I've walked through the tree, dropped all disable_early_printk() instances
found below arch/ and tagged the consoles with CON_BOOT if needed. The
code is tested on x86, sh (thanks to Paul) and mips (thanks to Ralf).Changes to last version: Rediffed against -rc3, adapted to mips cleanups by
Ralf, fixed "udbg-immortal" cmd line arg on powerpc.Signed-off-by: Gerd Hoffmann
Acked-by: Paul Mundt
Acked-by: Ralf Baechle
Cc: Andi Kleen
Cc: Alan Cox
Cc: Richard Henderson
Cc: Ivan Kokshaysky
Cc: Paul Mackerras
Cc: Benjamin Herrenschmidt
Cc: Jeremy Fitzhardinge
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
console.name[] is eight chars, but so is "earlyvga". So when we try to print
console->name when using earlyvga it runs off the end of the string.Make it bigger.
Diagnosed-by: Gerd Hoffmann
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Eternal quest to make
while true; do cat /proc/fs/xfs/stat >/dev/null 2>/dev/null; done
while true; do find /proc -type f 2>/dev/null | xargs cat >/dev/null 2>/dev/null; done
while true; do modprobe xfs; rmmod xfs; donework reliably continues and now kernel oopses in the following way:
BUG: unable to handle ... at virtual address 6b6b6b6b
EIP is at badness
process: cat
proc_oom_score
proc_info_read
sys_fstat64
vfs_read
proc_info_read
sys_readFailing code is prefetch hidden in list_for_each_entry() in badness().
badness() is reachable from two points. One is proc_oom_score, another
is out_of_memory() => select_bad_process() => badness().Second path grabs tasklist_lock, while first doesn't.
Signed-off-by: Alexey Dobriyan
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
LTP test sigaction_16_24 fails, because it expects sem_wait to be restarted
if SA_RESTART is set. sem_wait is implemented with futex_wait, that
currently doesn't support being restarted. Ulrich confirms that the call
should be restartable.Implement a restart_block method to handle the relative timeout, and allow
restarts.Signed-off-by: Nick Piggin
Cc: Ulrich Drepper
Cc: Rusty Russell
Cc: Roland McGrath
Cc: Oleg Nesterov
Acked-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
lguest uses the convenient futex infrastructure for inter-domain I/O, so
expose get_futex_key, get_key_refs (renamed get_futex_key_refs) and
drop_key_refs (renamed drop_futex_key_refs). Also means we need to expose the
union that these use.No code changes.
Signed-off-by: Rusty Russell
Cc: Andi Kleen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Signed-off-by: Dale Farnsworth.org
Cc: Alessandro Zummo
Cc: David Brownell
Cc: Jean Delvare
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add an RTC driver for Ricoh RS5C313 RTC chip.
[akpm@linux-foundation.org: Zillions of coding-style fixes]
[akpm@linux-foundation.org: build fixes]
Signed-off-by: Nobuhiro Iwamatsu
Cc: Alessandro Zummo
Cc: David Brownell
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fix units mismatch (jiffies vs msecs) in as-iosched.c, spotted by Xiaoning
Ding .Signed-off-by: Nick Piggin
Cc: Jens Axboe
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The jsm driver doesn't currently use the uart_handle_*_change helper
functions, which are the obvious place for things like linuxpps to tie
into (which it now does of course), and as a result the jsm driver can
not be used with linuxpps and anything else that ties into the
serial_core helper functions. This patch adds calls to these helper
functions whenever the value they manage changes. That actual storage
of the state is not modified since the jsm driver caches the current
settings (The 8250 driver reads them everytime a user asks for the
state), and only updates them whenever they change.Signed-off-by: Len Sorensen
Cc: Scott H Kilau
Cc: Wendy Xiong
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The jsm driver fails when you try to use the TIOCSSERIAL ioctl. The reason
is that the driver never sets uart_port.uartclk, causing the data received
using TIOCGSERIAL to not match the internal state of the driver. This
patch fixes this problem by settings the uartclk to the value used by the
serial_core (16 times the baud base).Signed-off-by: Len Sorensen
Cc: Scott H Kilau
Cc: Wendy Xiong
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Switch from private uclong, etc over to standard types.
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
At least on x86_64 the present cyclades.h is broken due to the wrong size
of uclong. This affects, of course, both the kernel and the user-level
utilities. The symptom is that cyzload refuses to load the firmware. I
also managed to freeze the machine when unloading the module.The patch below fixes this in an architecture-independent way. I have
tested it with 2.6.19 and the driver works fine again with a Cyclades-Z on
an Athlon 64 X2.[akpm@linux-foundation.org: fix warnings]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Kprobes doesn't scribble the kprobe.symbol_name field. Its only set by the
module when registering the probe. Modules that exercise good hygiene
using the "const" qualifier will see warnings...warning: assignment discards qualifiers from pointer target type
Make struct kprobe.symbol_name const char *
Signed-off-by: Ananth N Mavinakayanahalli
Signed-off-by: Jim Keniston
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Adds the needed TCGETS2/TCSETS2 ioctl calls, structures, defines and the like.
Tested against the test suite and passes. Other platforms should need
roughly the same change.Signed-off-by: Alan Cox
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
1) Introduces a new method in 'struct dentry_operations'. This method
called d_dname() might be called from d_path() to build a pathname for
special filesystems. It is called without locks.Future patches (if we succeed in having one common dentry for all
pipes/sockets) may need to change prototype of this method, but we now
use : char *d_dname(struct dentry *dentry, char *buffer, int buflen);2) Adds a dynamic_dname() helper function that eases d_dname() implementations
3) Defines d_dname method for sockets : No more sprintf() at socket
creation. This is delayed up to the moment someone does an access to
/proc/pid/fd/...4) Defines d_dname method for pipes : No more sprintf() at pipe
creation. This is delayed up to the moment someone does an access to
/proc/pid/fd/...A benchmark consisting of 1.000.000 calls to pipe()/close()/close() gives a
*nice* speedup on my Pentium(M) 1.6 Ghz :3.090 s instead of 3.450 s
Signed-off-by: Eric Dumazet
Acked-by: Christoph Hellwig
Acked-by: Linus Torvalds
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add support for finding out the current file position, open flags and
possibly other info in the future.These new entries are added:
/proc/PID/fdinfo/FD
/proc/PID/task/TID/fdinfo/FDFor each fd the information is provided in the following format:
pos: 1234
flags: 0100002[bunk@stusta.de: make struct proc_fdinfo_file_operations static]
Signed-off-by: Miklos Szeredi
Cc: Alexey Dobriyan
Signed-off-by: Adrian Bunk
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Change the order of fields of struct pid_entry (file fs/proc/base.c) in order
to avoid a hole on 64bit archs. (8 bytes saved per object)Also change all pid_entry arrays to be const qualified, to make clear they
must not be modified.Before (on x86_64) :
# size fs/proc/base.o
text data bss dec hex filename
15549 2192 0 17741 454d fs/proc/base.oAfter :
# size fs/proc/base.o
text data bss dec hex filename
17229 176 0 17405 43fd fs/proc/base.oThats 336 bytes saved on kernel size on x86_64
Signed-off-by: Eric Dumazet
Acked-by: "Eric W. Biederman"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Signed-off-by: Amit Choudhary
Cc: Paul Fulghum
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Signed-off-by: Robert P. J. Day
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Signed-off-by: Robert P. J. Day
Cc: Markus Lidel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The /proc/pid/ "maps", "smaps", and "numa_maps" files contain sensitive
information about the memory location and usage of processes. Issues:- maps should not be world-readable, especially if programs expect any
kind of ASLR protection from local attackers.
- maps cannot just be 0400 because "-D_FORTIFY_SOURCE=2 -O2" makes glibc
check the maps when %n is in a *printf call, and a setuid(getuid())
process wouldn't be able to read its own maps file. (For reference
see http://lkml.org/lkml/2006/1/22/150)
- a system-wide toggle is needed to allow prior behavior in the case of
non-root applications that depend on access to the maps contents.This change implements a check using "ptrace_may_attach" before allowing
access to read the maps contents. To control this protection, the new knob
/proc/sys/kernel/maps_protect has been added, with corresponding updates to
the procfs documentation.[akpm@linux-foundation.org: build fixes]
[akpm@linux-foundation.org: New sysctl numbers are old hat]
Signed-off-by: Kees Cook
Cc: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
WARNING: vmlinux - Section mismatch: reference to
.init.text:eisa_root_register from .text between 'virtual_eisa_root_init' (at
offset 0xc026b80f) and 'cpufreq_debug_disable_ratelimit'Cc: Dave Jones
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
It misspelled "MODVERSIONS" preprocessor variable with "CONFIG_MODVERSIONS".
Just kill it all.Signed-off-by: Robert P. J. Day
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch kills the "ignoring return value of 'device_create_file'"
warning message.Signed-off-by: Monakhov Dmitriy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Cleaning up of pci_find_device in drivers/telephony/ixj.c.
Signed-off-by: Surya Prabhakar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
tAdd adds support for devices living in MMIO space to the Infineon TPM
driver. These can be found on some of the newer HP ia64 systems.Signed-off-by: Alex Williamson
Cc: Kylene Jo Hall
Acked-by: Marcel Selhorst
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
We don't have a routine called namei() anymore since at least 2.3.x, and
the comment is just totally out of sync with the current lookup logic.Signed-off-by: Christoph Hellwig
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
inode->i_sb is always set, not need to check for it.
Signed-off-by: Christoph Hellwig
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
WARN_ON(de && de->deleted); is sooo unreliable. Why?
proc_lookup remove_proc_entry
=========== =================
lock_kernel();
spin_lock(&proc_subdir_lock);
[find proc entry]
spin_unlock(&proc_subdir_lock);
spin_lock(&proc_subdir_lock);
[find proc entry]proc_get_inode
==============
WARN_ON(de && de->deleted); ...if (!atomic_read(&de->count))
free_proc_entry(de);
else
de->deleted = 1;So, if you have some strange oops [1], and doesn't see this WARN_ON it means
nothing.[1] try_module_get() of module which doesn't exist, two lines below
should suffice, or not?Signed-off-by: Alexey Dobriyan
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fix the following race:
proc_readdir remove_proc_entry
============ =================spin_lock(&proc_subdir_lock);
[choose PDE to start filldir from]
spin_unlock(&proc_subdir_lock);
spin_lock(&proc_subdir_lock);
[find PDE]
[free PDE, refcount is 0]
spin_unlock(&proc_subdir_lock);
/* boom */
if (filldir(dirent, de->name, ...[de_put on error path --adobriyan]
Signed-off-by: Darrick J. Wong
Signed-off-by: Alexey Dobriyan
Cc: "Eric W. Biederman"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
proc_lookup remove_proc_entry
=========== =================lock_kernel();
spin_lock(&proc_subdir_lock);
[find PDE with refcount 0]
spin_unlock(&proc_subdir_lock);
spin_lock(&proc_subdir_lock);
[find PDE with refcount 0]
[check refcount and free PDE]
spin_unlock(&proc_subdir_lock);
proc_get_inode:
de_get(de); /* boom */Signed-off-by: Alexey Dobriyan
Cc: "Eric W. Biederman"
Cc: Oleg Nesterov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
There's a slight problem with filesystem type representation in fuse
based filesystems.From the kernel's view, there are just two filesystem types: fuse and
fuseblk. From the user's view there are lots of different filesystem
types. The user is not even much concerned if the filesystem is fuse based
or not. So there's a conflict of interest in how this should be
represented in fstab, mtab and /proc/mounts.The current scheme is to encode the real filesystem type in the mount
source. So an sshfs mount looks like this:sshfs#user@server:/ /mnt/server fuse rw,nosuid,nodev,...
This url-ish syntax works OK for sshfs and similar filesystems. However
for block device based filesystems (ntfs-3g, zfs) it doesn't work, since
the kernel expects the mount source to be a real device name.A possibly better scheme would be to encode the real type in the type
field as "type.subtype". So fuse mounts would look like this:/dev/hda1 /mnt/windows fuseblk.ntfs-3g rw,...
user@server:/ /mnt/server fuse.sshfs rw,nosuid,nodev,...This patch adds the necessary code to the kernel so that this can be
correctly displayed in /proc/mounts.Signed-off-by: Miklos Szeredi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
strlcpy already accounts for the trailing zero in its length
computation, so there is no need to substract one to the buffer size.Signed-off-by: Jean Delvare
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Epoll is doing multiple passes over the ready set at the moment, because of
the constraints over the f_op->poll() call. Looking at the code again, I
noticed that we already hold the epoll semaphore in read, and this
(together with other locking conditions that hold while doing an
epoll_wait()) can lead to a smarter way [1] to "ship" events to userspace
(in a single pass).This is a stress application that can be used to test the new code. It
spwans multiple thread and call epoll_wait() and epoll_ctl() from many
threads. Stress tested on my dual Opteron 254 w/out any problems.http://www.xmailserver.org/totalmess.c
This is not a benchmark, just something that tries to stress and exploit
possible problems with the new code.
Also, I made a stupid micro-benchmark:http://www.xmailserver.org/epwbench.c
[1] Considering that epoll must be thread-safe, there are five ways we can
be hit during an epoll_wait() transfer loop (ep_send_events()):1) The epoll fd going away and calling ep_free
This just can't happen, since we did an fget() in sys_epoll_wait2) An epoll_ctl(EPOLL_CTL_DEL)
This can't happen because epoll_ctl() gets ep->sem in write, and
we're holding it in read during ep_send_events()3) An fd stored inside the epoll fd going away
This can't happen because in eventpoll_release_file() we get
ep->sem in write, and we're holding it in read during
ep_send_events()4) Another epoll_wait() happening on another thread
They both can be inside ep_send_events() at the same time, we get
(splice) the ready-list under the spinlock, so each one will get
its own ready list. Note that an fd cannot be at the same time
inside more than one ready list, because ep_poll_callback() will
not re-queue it if it sees it already linked:if (ep_is_linked(&epi->rdllink))
goto is_linked;Another case that can happen, is two concurrent epoll_wait(),
coming in with a userspace event buffer of size, say, ten.
Suppose there are 50 event ready in the list. The first
epoll_wait() will "steal" the whole list, while the second, seeing
no events, will go to sleep. But at the end of ep_send_events() in
the first epoll_wait(), we will re-inject surplus ready fds, and we
will trigger the proper wake_up to the second epoll_wait().5) ep_poll_callback() hitting us asyncronously
This is the tricky part. As I said above, the ep_is_linked() test
done inside ep_poll_callback(), will guarantee us that until the
item will result linked to a list, ep_poll_callback() will not try
to re-queue it again (read, write data on any of its members). When
we do a list_del() in ep_send_events(), the item will still satisfy
the ep_is_linked() test (whatever data is written in prev/next,
it'll never be its own pointer), so ep_poll_callback() will still
leave us alone. It's only after the eventual smp_mb()+INIT_LIST_HEAD(&epi->rdllink)
that it'll become visible to ep_poll_callback(), but at the point
we're already past it.[akpm@osdl.org: 80 cols]
Signed-off-by: Davide Libenzi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
