- 26 Jun, 2006 40 commits
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Tobias Oed authored
The driver pdc202xx_old requires CONFIG_BLK_DEV_IDEDMA, so it's always defined Signed-off-by:
Tobias Oed <tobiasoed@hotmail.com> Acked-by:
Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl> Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com> Signed-off-by:
Andrew Morton <akpm@osdl.org> Signed-off-by:
Linus Torvalds <torvalds@osdl.org>
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Ingo Molnar authored
Michal Piotrowski reported the following validator assert: hdd: set_drive_speed_status: status=0x51 { DriveReady SeekComplete Error } hdd: set_drive_speed_status: error=0xb4 { AbortedCommand LastFailedSense=0x0b } ============================ [ BUG: illegal lock usage! ] ---------------------------- illegal {in-hardirq-W} -> {hardirq-on-W} usage. hdparm/1821 [HC0[0]:SC0[0]:HE1:SE1] takes: (ide_lock){++..}, at: [<c0268388>] ide_dump_opcode+0x13/0x9b [...] stack backtrace: [<c0104513>] show_trace+0x1b/0x20 [<c01045f1>] dump_stack+0x1f/0x24 [<c013976c>] print_usage_bug+0x1a5/0x1b1 [<c0139e90>] mark_lock+0x2ca/0x4f7 [<c013aa96>] __lockdep_acquire+0x47e/0xaa4 [<c013b536>] lockdep_acquire+0x67/0x7f [<c030552d>] _spin_lock+0x24/0x32 [<c0268388>] ide_dump_opcode+0x13/0x9b [<c02688b6>] ide_dump_status+0x4a6/0x4cc [<c0267ae6>] ide_config_drive_speed+0x32a/0x33a [<c0262dc5>] piix_tune_chipset+0x2ed/0x2f8 [<c0262e31>] piix_config_drive_xfer_rate+0x61/0xb5 [<c0263a82>] set_using_dma+0x2f/0x60 [<c0263bee>] ide_write_setting+0x4a/0xc3 [<c02647ca>] generic_ide_ioctl+0x8a/0x47f [<f886003a>] idecd_ioctl+0xfd/0x133 [ide_cd] [<c01f1fff>] blkdev_driver_ioctl+0x4b/0x5f [<c01f2783>] blkdev_ioctl+0x770/0x7bd [<c017dc0d>] block_ioctl+0x1f/0x21 [<c0189353>] do_ioctl+0x27/0x6e [<c0189604>] vfs_ioctl+0x26a/0x280 [<c0189667>] sys_ioctl+0x4d/0x7e [<c0305ed2>] sysenter_past_esp+0x63/0xa1 in ide_dump_opcode() takes the ide_lock in an irq-unsafe manner, i.e. this function expects to be called with irqs disabled. But ide_dump_ata[pi]_status() doesnt do that - it enables interrupts specifically. That is a no-no - what guarantees that another IDE port couldnt generate an IDE interrupt while we are dumping this error? The fix is to turn the irq-enabling in these functions into irq-disabling. Signed-off-by:Ingo Molnar <mingo@elte.hu> Cc: Michal Piotrowski <michal.k.k.piotrowski@gmail.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl> Signed-off-by:
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Sergei Shtylyov authored
Remove the busproc from pdc202xx_old.c because: - it handles the obsolete HDIO_TRISTATE_HWIF ioctl instead of the modern HDIO_SET_BUSSTATE, so treats its argument wrong; - I don't think that tristating both channels is good idea (probably can't be done otherwise since there seems to be only single bit controlling this). Signed-off-by:
Sergei Shtylyov <sshtylyov@ru.mvista.com> Cc: Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl> Acked-by:
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Sergei Shtylyov authored
The function ide_timing_compute() fails to *actually* take drive's specified minimum PIO/DMA cycle times into account -- when doing this, it calls ide_timing_merge() on the 'struct ide_timing' argument which contains garbage at the moment, and then ultimately destroys the read cycle time by quantizing the ide_timing[] entry, instead of copying from that entry to the argument structure, and only then doing a merge/quantize. Cc: Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl> Acked-by:
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Al Boldi authored
During an STR resume cycle, the ide master disk times-out when there is also a slave present (especially CD). Increasing the timeout in ide-io from 10,000 to 100,000 fixes this problem. Acked-by:
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Alan Cox authored
This bit us a few kernels ago, and for some reason never made it's way upstream. https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=144743 Kernel panic - not syncing: drivers/ide/pci/piix.c:231: spin_lock(drivers/ide/ide.c:c03cef28) already locked by driver/ide/ide-iops.c/1153. Signed-off-by:
Dave Jones <davej@redhat.com> Cc: Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl> Cc: Dave Jones <davej@redhat.com> Cc: Jens Axboe <axboe@suse.de> Signed-off-by:
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Tobias Oed authored
Remove a call to hwif->tuneproc() on the error path of config_chipset_for_dma(), as its single caller (pdc202xx_config_drive_xfer_rate()) will do the call in that case. Signed-off-by:
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Oleg Nesterov authored
After the previous patch SIGNAL_GROUP_EXIT implies a pending SIGKILL, we can remove this check from copy_process() because we already checked !signal_pending(). Signed-off-by:
Oleg Nesterov <oleg@tv-sign.ru> Cc: Roland McGrath <roland@redhat.com> Signed-off-by:
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Oleg Nesterov authored
This patch optimizes zap_threads() for the case when there are no ->mm users except the current's thread group. In that case we can avoid 'for_each_process()' loop. It also adds a useful invariant: SIGNAL_GROUP_EXIT (if checked under ->siglock) always implies that all threads (except may be current) have pending SIGKILL. Signed-off-by:
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Oleg Nesterov authored
This is a preparation for the next patch. No functional changes. Basically, this patch moves '->flags & SIGNAL_GROUP_EXIT' check into zap_threads(), and 'complete(vfork_done)' into coredump_wait outside of ->mmap_sem protected area. Signed-off-by:
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Oleg Nesterov authored
This patch removes tasklist_lock from zap_threads(). This is safe wrt: do_exit: The caller holds mm->mmap_sem. This means that task which shares the same ->mm can't pass exit_mm(), so it can't be unhashed from init_task.tasks or ->thread_group lists. fork: None of sub-threads can fork after zap_process(leader). All processes which were created before this point should be visible to zap_threads() because copy_process() adds the new process to the tail of init_task.tasks list, and ->siglock lock/unlock provides a memory barrier. de_thread: It does list_replace_rcu(&leader->tasks, ¤t->tasks). So zap_threads() will see either old or new leader, it does not matter. However, it can change p->sighand, so we should use lock_task_sighand() in zap_process(). Signed-off-by:
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Oleg Nesterov authored
With this patch zap_process() sets SIGNAL_GROUP_EXIT while sending SIGKILL to the thread group. This means that a TASK_TRACED task 1. Will be awakened by signal_wake_up(1) 2. Can't sleep again via ptrace_notify() 3. Can't go to do_signal_stop() after return from ptrace_stop() in get_signal_to_deliver() So we can remove all ptrace related stuff from coredump path. Signed-off-by:
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Oleg Nesterov authored
With this patch a thread group is killed atomically under ->siglock. This is faster because we can use sigaddset() instead of force_sig_info() and this is used in further patches. Signed-off-by:
Roland McGrath <roland@redhat.com> Signed-off-by:
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Oleg Nesterov authored
zap_threads() iterates over all threads to find those ones which share current->mm. All threads in the thread group share the same ->mm, so we can skip entire thread group if it has another ->mm. This patch shifts the killing of thread group into the newly added zap_process() function. This looks as unnecessary complication, but it is used in further patches. Signed-off-by:
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Oleg Nesterov authored
We should keep the value of old_leader->tasks.next in de_thread, otherwise we can't do for_each_process/do_each_thread without tasklist_lock held. Signed-off-by:
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Eric Paris authored
Below is a patch to add a new /proc/self/attr/sockcreate A process may write a context into this interface and all subsequent sockets created will be labeled with that context. This is the same idea as the fscreate interface where a process can specify the label of a file about to be created. At this time one envisioned user of this will be xinetd. It will be able to better label sockets for the actual services. At this time all sockets take the label of the creating process, so all xinitd sockets would just be labeled the same. I tested this by creating a tcp sender and listener. The sender was able to write to this new proc file and then create sockets with the specified label. I am able to be sure the new label was used since the avc denial messages kicked out by the kernel included both the new security permission setsockcreate and all the socket denials were for the new label, not the label of the running process. Signed-off-by:
Eric Paris <eparis@redhat.com> Signed-off-by:
James Morris <jmorris@namei.org> Cc: Chris Wright <chrisw@sous-sol.org> Signed-off-by:
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Oleg Nesterov authored
Try to make next_tid() a bit more readable and deletes unnecessary "pid_alive(pos)" check. Signed-off-by:
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Oleg Nesterov authored
first_tid: /* If nr exceeds the number of threads there is nothing todo */ if (nr) { if (nr >= get_nr_threads(leader)) goto done; } This is not reliable: sub-threads can exit after this check, so the 'for' loop below can overlap and proc_task_readdir() can return an already filldir'ed dirents. for (; pos && pid_alive(pos); pos = next_thread(pos)) { if (--nr > 0) continue; Off-by-one error, will return 'leader' when nr == 1. This patch tries to fix these problems and simplify the code. Signed-off-by: -
Eric W. Biederman authored
This is just like my previous removal of tasklist_lock from first_tgid, and next_tgid. It simply had to wait until it was rcu safe to walk the thread list. This should be the last instance of the tasklist_lock in proc. So user processes should not be able to influence the tasklist lock hold times. Signed-off-by:
Eric W. Biederman <ebiederm@xmission.com> Signed-off-by:
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Eric W. Biederman authored
In process of getting proc_fd_access_allowed to work it has developed a few warts. In particular the special case that always allows introspection and the special case to allow inspection of kernel threads. The special case for introspection is needed for /proc/self/mem. The special case for kernel threads really should be overridable by security modules. So consolidate these checks into ptrace.c:may_attach(). The check to always allow introspection is trivial. The check to allow access to kernel threads, and zombies is a little trickier. mem_read and mem_write already verify an mm exists so it isn't needed twice. proc_fd_access_allowed only doesn't want a check to verify task->mm exits, s it prevents all access to kernel threads. So just move the task->mm check into ptrace_attach where it is needed for practical reasons. I did a quick audit and none of the security modules in the kernel seem to care if they are passed a task without an mm into security_ptrace. So the above move should be safe and it allows security modules to come up with more restrictive policy. Signed-off-by:
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Eric W. Biederman authored
Since 2.2 we have been doing a chroot check to see if it is appropriate to return a read or follow one of these magic symlinks. The chroot check was asking a question about the visibility of files to the calling process and it was actually checking the destination process, and not the files themselves. That test was clearly bogus. In my first pass through I simply fixed the test to check the visibility of the files themselves. That naive approach to fixing the permissions was too strict and resulted in cases where a task could not even see all of it's file descriptors. What has disturbed me about relaxing this check is that file descriptors are per-process private things, and they are occasionaly used a user space capability tokens. Looking a little farther into the symlink path on /proc I did find userid checks and a check for capability (CAP_DAC_OVERRIDE) so there were permissions checking this. But I was still concerned about privacy. Besides /proc there is only one other way to find out this kind of information, and that is ptrace. ptrace has been around for a long time and it has a well established security model. So after thinking about it I finally realized that the permission checks that make sense are the permission checks applied to ptrace_attach. The checks are simple per process, and won't cause nasty surprises for people coming from less capable unices. Unfortunately there is one case that the current ptrace_attach test does not cover: Zombies and kernel threads. Single stepping those kinds of processes is impossible. Being able to see which file descriptors are open on these tasks is important to lsof, fuser and friends. So for these special processes I made the rule you can't find out unless you have CAP_SYS_PTRACE. These proc permission checks should now conform to the principle of least surprise. As well as using much less code to implement :) Signed-off-by:
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Eric W. Biederman authored
The code doesn't need to sleep to when making this check so I can just do the comparison and not worry about the reference counts. TODO: While looking at this I realized that my original cleanup did not push the permission check far enough down into the stack. The call of proc_check_dentry_visible needs to move out of the generic proc readlink/follow link code and into the individual get_link instances. Otherwise the shared resources checks are not quite correct (shared files_struct does not require a shared fs_struct), and there are races with unshare. Signed-off-by:
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Eric W. Biederman authored
Incrementally update my proc-dont-lock-task_structs-indefinitely patches so that they work with struct pid instead of struct task_ref. Mostly this is a straight 1-1 substitution. Signed-off-by:
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Eric W. Biederman authored
Every inode in /proc holds a reference to a struct task_struct. If a directory or file is opened and remains open after the the task exits this pinning continues. With 8K stacks on a 32bit machine the amount pinned per file descriptor is about 10K. Normally I would figure a reasonable per user process limit is about 100 processes. With 80 processes, with a 1000 file descriptors each I can trigger the 00M killer on a 32bit kernel, because I have pinned about 800MB of useless data. This patch replaces the struct task_struct pointer with a pointer to a struct task_ref which has a struct task_struct pointer. The so the pinning of dead tasks does not happen. The code now has to contend with the fact that the task may now exit at any time. Which is a little but not muh more complicated. With this change it takes about 1000 processes each opening up 1000 file descriptors before I can trigger the OOM killer. Much better. [mlp@google.com: task_mmu small fixes] Signed-off-by:
Prasanna Meda <mlp@google.com> Signed-off-by:
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Eric W. Biederman authored
Currently in /proc at several different places we define buffers to hold a process id, or a file descriptor . In most of them we use either a hard coded number or a different define. Modify them all to use PROC_NUMBUF, so the code has a chance of being maintained. Signed-off-by:
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Eric W. Biederman authored
Like the bug Oleg spotted in first_tid there was also a small off by one error in first_tgid, when a seek was done on the /proc directory. This fixes that and changes the code structure to make it a little more obvious what is going on. Signed-off-by:
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Eric W. Biederman authored
Since we no longer need the tasklist_lock for get_task_struct the lookup methods no longer need the tasklist_lock. This just depends on my previous patch that makes get_task_struct() rcu safe. Signed-off-by:
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Eric W. Biederman authored
We don't need the tasklist_lock to safely iterate through processes anymore. This depends on my previous to task patches that make get_task_struct rcu safe, and that make next_task() rcu safe. I haven't gotten first_tid/next_tid yet only because next_thread is missing an rcu_dereference. Signed-off-by:
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Eric W. Biederman authored
There are a couple of problems this patch addresses. - /proc/<tgid>/task currently does not work correctly if you stop reading in the middle of a directory. - /proc/ currently requires a full pass through the task list with the tasklist lock held, to determine there are no more processes to read. - The hand rolled integer to string conversion does not properly running out of buffer space. - We seem to be batching reading of pids from the tasklist without reason, and complicating the logic of the code. This patch addresses that by changing how tasks are processed. A first_<task_type> function is built that handles restarts, and a next_<task_type> function is built that just advances to the next task. first_<task_type> when it detects a restart usually uses find_task_by_pid. If that doesn't work because there has been a seek on the directory, or we have already given a complete directory listing, it first checks the number tasks of that type, and only if we are under that count does it walk through all of the tasks to find the one we are interested in. The code that fills in the directory is simpler because there is only a single for loop. The hand rolled integer to string conversion is replaced by snprintf which should handle the the out of buffer case correctly. Signed-off-by:
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Eric W. Biederman authored
proc_lookup and task exiting are not synchronized, although some of the previous code may have suggested that. Every time before we reuse a dentry namei.c calls d_op->derevalidate which prevents us from reusing a stale dcache entry. Unfortunately it does not prevent us from returning a stale dcache entry. This race has been explicitly plugged in proc_pid_lookup but there is nothing to confine it to just that proc lookup function. So to prevent the race I call revalidate explictily in all of the proc lookup functions after I call d_add, and report an error if the revalidate does not succeed. Years ago Al Viro did something similar but those changes got lost in the churn. Signed-off-by:
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Eric W. Biederman authored
To keep the dcache from filling up with dead /proc entries we flush them on process exit. However over the years that code has gotten hairy with a dentry_pointer and a lock in task_struct and misdocumented as a correctness feature. I have rewritten this code to look and see if we have a corresponding entry in the dcache and if so flush it on process exit. This removes the extra fields in the task_struct and allows me to trivially handle the case of a /proc/<tgid>/task/<pid> entry as well as the current /proc/<pid> entries. Signed-off-by:
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Eric W. Biederman authored
All of the functions for proc_maps_operations are already defined in task_mmu.c so move the operations structure to keep the functionality together. Since task_nommu.c implements a dummy version of /proc/<pid>/maps give it a simplified version of proc_maps_operations that it can modify to best suit its needs. Signed-off-by:
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Eric W. Biederman authored
Use getattr to get an accurate link count when needed. This is cheaper and more accurate than trying to derive it by walking the thread list of a process. Especially as it happens when needed stat instead of at readdir time. Signed-off-by:
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Eric W. Biederman authored
Long ago and far away in 2.2 we started checking to ensure the files we displayed in /proc were visible to the current process. It was an unsophisticated time and no one was worried about functions full of FIXMES in a stable kernel. As time passed the function became sacred and was enshrined in the shrine of how things have always been. The fixes came in but only to keep the function working no one really remembering or documenting why we did things that way. The intent and the functionality make a lot of sense. Don't let /proc be an access point for files a process can see no other way. The implementation however is completely wrong. We are currently checking the root directories of the two processes, we are not checking the actual file descriptors themselves. We are strangely checking with a permission method instead of just when we use the data. This patch fixes the logic to actually check the file descriptors and make a note that implementing a permission method for this part of /proc almost certainly indicates a bug in the reasoning. Signed-off-by:
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Eric W. Biederman authored
The inode operations only exist to support the proc_permission function. Currently mem_read and mem_write have all the same permission checks as ptrace. The fs check makes no sense in this context, and we can trivially get around it by calling ptrace. So simply the code by killing the strange weird case. Signed-off-by:
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Eric W. Biederman authored
First we can access every /proc/<tgid>/task/<pid> directory as /proc/<pid> so proc_task_permission is not usefully limiting visibility. Second having related filesystems information should have nothing to do with process visibility. kill does not implement any checks like that. Signed-off-by:
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Eric W. Biederman authored
The sole renaming use of proc_inode.type is to discover the file descriptor number, so just store the file descriptor number and don't wory about processing this field. This removes any /proc limits on the maximum number of file descriptors, and clears the path to make the hard coded /proc inode numbers go away. Signed-off-by:
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Eric W. Biederman authored
Currently in /proc if the task is dumpable all of files are owned by the tasks effective users. Otherwise the files are owned by root. Unless it is the /proc/<tgid>/ or /proc/<tgid>/task/<pid> directory in that case we always make the directory owned by the effective user. However the special case for directories is pointless except as a way to read the effective user, because the permissions on both of those directories are world readable, and executable. /proc/<tgid>/status provides a much better way to read a processes effecitve userid, so it is silly to try to provide that on the directory. So this patch simplifies the code by removing a pointless special case and gets us one step closer to being able to remove the hard coded /proc inode numbers. Signed-off-by:
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Eric W. Biederman authored
The removed fields are already set by proc_alloc_inode. Initializing them in proc_alloc_inode implies they need it for proper cleanup. At least ei->pde was not set on all paths making it look like proc_alloc_inode was buggy. So just remove the redundant assignments. Signed-off-by:
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Eric W. Biederman authored
We already call everything except do_proc_readlink outside of the BKL in proc_pid_followlink, and there appears to be nothing in do_proc_readlink that needs any special protection. So remove this leftover from one of the BKL cleanup efforts. Signed-off-by:
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