1. 02 Oct, 2006 11 commits
    • Eric W. Biederman's avatar
      [PATCH] pid: export the symbols needed to use struct pid * · bbf73147
      Eric W. Biederman authored
      
      
      pids aren't something that drivers should care about.  However there are a lot
      of helper layers in the kernel that do care, and are built as modules.  Before
      I can convert them to using struct pid instead of pid_t I need to export the
      appropriate symbols so they can continue to be built.
      Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      bbf73147
    • Eric W. Biederman's avatar
      [PATCH] pid: implement signal functions that take a struct pid * · c4b92fc1
      Eric W. Biederman authored
      
      
      Currently the signal functions all either take a task or a pid_t argument.
      This patch implements variants that take a struct pid *.  After all of the
      users have been update it is my intention to remove the variants that take a
      pid_t as using pid_t can be more work (an extra hash table lookup) and
      difficult to get right in the presence of multiple pid namespaces.
      
      There are two kinds of functions introduced in this patch.  The are the
      general use functions kill_pgrp and kill_pid which take a priv argument that
      is ultimately used to create the appropriate siginfo information, Then there
      are _kill_pgrp_info, kill_pgrp_info, kill_pid_info the internal implementation
      helpers that take an explicit siginfo.
      
      The distinction is made because filling out an explcit siginfo is tricky, and
      will be even more tricky when pid namespaces are introduced.
      Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      c4b92fc1
    • Eric W. Biederman's avatar
      [PATCH] pid: add do_each_pid_task · 558cb325
      Eric W. Biederman authored
      
      
      To avoid pid rollover confusion the kernel needs to work with struct pid *
      instead of pid_t.  Currently there is not an iterator that walks through all
      of the tasks of a given pid type starting with a struct pid.  This prevents us
      replacing some pid_t instances with struct pid.  So this patch adds
      do_each_pid_task which walks through the set of task for a given pid type
      starting with a struct pid.
      Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      558cb325
    • Eric W. Biederman's avatar
      [PATCH] pid: implement access helpers for a tacks various process groups · 22c935f4
      Eric W. Biederman authored
      
      
      In the last round of cleaning up the pid hash table a more general struct pid
      was introduced, that can be referenced counted.
      
      With the more general struct pid most if not all places where we store a pid_t
      we can now store a struct pid * and remove the need for a hash table lookup,
      and avoid any possible problems with pid roll over.
      
      Looking forward to the pid namespaces struct pid * gives us an absolute form a
      pid so we can compare and use them without caring which pid namespace we are
      in.
      
      This patchset introduces the infrastructure needed to use struct pid instead
      of pid_t, and then it goes on to convert two different kernel users that
      currently store a pid_t value.
      
      There are a lot more places to go but this is enough to get the basic idea.
      
      Before we can merge a pid namespace patch all of the kernel pid_t users need
      to be examined.  Those that deal with user space processes need to be
      converted to using a struct pid *.  Those that deal with kernel processes need
      to converted to using the kthread api.  A rare few that only use their current
      processes pid values get to be left alone.
      
      This patch:
      
      task_session returns the struct pid of a tasks session.
      task_pgrp    returns the struct pid of a tasks process group.
      task_tgid    returns the struct pid of a tasks thread group.
      task_pid     returns the struct pid of a tasks process id.
      
      These can be used to avoid unnecessary hash table lookups, and to implement
      safe pid comparisions in the face of a pid namespace.
      Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      22c935f4
    • Eric W. Biederman's avatar
      [PATCH] proc: give the root directory a task · f6c7a1f3
      Eric W. Biederman authored
      
      
      Helper functions in base.c like proc_pident_readdir and proc_pident_lookup
      assume the directories have an associated task, and cannot currently be used
      on the /proc root directory because it does not have such a task.
      
      This small changes allows for base.c to be simplified and later when multiple
      pid spaces are introduced it makes getting the needed context information
      trivial.
      Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      f6c7a1f3
    • Eric W. Biederman's avatar
      [PATCH] proc: modify proc_pident_lookup to be completely table driven · 20cdc894
      Eric W. Biederman authored
      
      
      Currently proc_pident_lookup gets the names and types from a table and then
      has a huge switch statement to get the inode and file operations it needs.
      That is silly and is becoming increasingly hard to maintain so I just put all
      of the information in the table.
      Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      20cdc894
    • Eric W. Biederman's avatar
      [PATCH] proc: reorder the functions in base.c · 28a6d671
      Eric W. Biederman authored
      
      
      There were enough changes in my last round of cleaning up proc I had to break
      up the patch series into smaller chunks, and my last chunk never got resent.
      
      This patchset gives proc dynamic inode numbers (the static inode numbers were
      a pain to maintain and prevent all kinds of things), and removes the horrible
      switch statements that had to be kept in sync with everything else.  Being
      fully table driver takes us 90% of the way of being able to register new
      process specific attributes in proc.
      
      This patch:
      
      Group the functions by what they implement instead of by type of operation.
      As it existed base.c was quickly approaching the point where it could not be
      followed.
      
      No functionality or code changes asside from adding/removing forward
      declartions are implemented in this patch.
      Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      28a6d671
    • Eric W. Biederman's avatar
      [PATCH] proc: readdir race fix (take 3) · 0804ef4b
      Eric W. Biederman authored
      
      
      The problem: An opendir, readdir, closedir sequence can fail to report
      process ids that are continually in use throughout the sequence of system
      calls.  For this race to trigger the process that proc_pid_readdir stops at
      must exit before readdir is called again.
      
      This can cause ps to fail to report processes, and it is in violation of
      posix guarantees and normal application expectations with respect to
      readdir.
      
      Currently there is no way to work around this problem in user space short
      of providing a gargantuan buffer to user space so the directory read all
      happens in on system call.
      
      This patch implements the normal directory semantics for proc, that
      guarantee that a directory entry that is neither created nor destroyed
      while reading the directory entry will be returned.  For directory that are
      either created or destroyed during the readdir you may or may not see them.
       Furthermore you may seek to a directory offset you have previously seen.
      
      These are the guarantee that ext[23] provides and that posix requires, and
      more importantly that user space expects.  Plus it is a simple semantic to
      implement reliable service.  It is just a matter of calling readdir a
      second time if you are wondering if something new has show up.
      
      These better semantics are implemented by scanning through the pids in
      numerical order and by making the file offset a pid plus a fixed offset.
      
      The pid scan happens on the pid bitmap, which when you look at it is
      remarkably efficient for a brute force algorithm.  Given that a typical
      cache line is 64 bytes and thus covers space for 64*8 == 200 pids.  There
      are only 40 cache lines for the entire 32K pid space.  A typical system
      will have 100 pids or more so this is actually fewer cache lines we have to
      look at to scan a linked list, and the worst case of having to scan the
      entire pid bitmap is pretty reasonable.
      
      If we need something more efficient we can go to a more efficient data
      structure for indexing the pids, but for now what we have should be
      sufficient.
      
      In addition this takes no additional locks and is actually less code than
      what we are doing now.
      
      Also another very subtle bug in this area has been fixed.  It is possible
      to catch a task in the middle of de_thread where a thread is assuming the
      thread of it's thread group leader.  This patch carefully handles that case
      so if we hit it we don't fail to return the pid, that is undergoing the
      de_thread dance.
      
      Thanks to KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> for
      providing the first fix, pointing this out and working on it.
      
      [oleg@tv-sign.ru: fix it]
      Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
      Acked-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Signed-off-by: default avatarOleg Nesterov <oleg@tv-sign.ru>
      Cc: Jean Delvare <jdelvare@suse.de>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      0804ef4b
    • Randy Dunlap's avatar
      [PATCH] list module taint flags in Oops/panic · 2bc2d61a
      Randy Dunlap authored
      
      
      When listing loaded modules during an oops or panic, also list each
      module's Tainted flags if non-zero (P: Proprietary or F: Forced load only).
      
      If a module is did not taint the kernel, it is just listed like
      	usbcore
      but if it did taint the kernel, it is listed like
      	wizmodem(PF)
      
      Example:
      [ 3260.121718] Unable to handle kernel NULL pointer dereference at 0000000000000000 RIP:
      [ 3260.121729]  [<ffffffff8804c099>] :dump_test:proc_dump_test+0x99/0xc8
      [ 3260.121742] PGD fe8d067 PUD 264a6067 PMD 0
      [ 3260.121748] Oops: 0002 [1] SMP
      [ 3260.121753] CPU 1
      [ 3260.121756] Modules linked in: dump_test(P) snd_pcm_oss snd_mixer_oss snd_seq snd_seq_device ide_cd generic ohci1394 snd_hda_intel snd_hda_codec snd_pcm snd_timer snd ieee1394 snd_page_alloc piix ide_core arcmsr aic79xx scsi_transport_spi usblp
      [ 3260.121785] Pid: 5556, comm: bash Tainted: P      2.6.18-git10 #1
      
      [Alternatively, I can look into listing tainted flags with 'lsmod',
      but that won't help in oopsen/panics so much.]
      
      [akpm@osdl.org: cleanup]
      Signed-off-by: default avatarRandy Dunlap <rdunlap@xenotime.net>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      2bc2d61a
    • Dean Nelson's avatar
      [PATCH] make genpool allocator adhere to kernel-doc standards · a58cbd7c
      Dean Nelson authored
      
      
      The exported kernel interfaces of genpool allocator need to adhere to
      the requirements of kernel-doc.
      Signed-off-by: default avatarDean Nelson <dcn@sgi.com>
      Cc: Steve Wise <swise@opengridcomputing.com>
      Acked-by: default avatarRandy Dunlap <rdunlap@xenotime.net>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      a58cbd7c
    • Steve Wise's avatar
      [PATCH] LIB: add gen_pool_destroy() · 322acc96
      Steve Wise authored
      
      
      Modules using the genpool allocator need to be able to destroy the data
      structure when unloading.
      Signed-off-by: default avatarSteve Wise <swise@opengridcomputing.com>
      Cc: Randy Dunlap <rdunlap@xenotime.net>
      Cc: Dean Nelson <dcn@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      322acc96
  2. 01 Oct, 2006 29 commits