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path: root/fs/proc/base.c
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2006-10-02[PATCH] introduce get_task_pid() to fix unsafe get_pid()Oleg Nesterov
proc_pid_make_inode: ei->pid = get_pid(task_pid(task)); I think this is not safe. get_pid() can be preempted after checking "pid != NULL". Then the task exits, does detach_pid(), and RCU frees the pid. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02[PATCH] proc: comment what proc_fill_cache doesEric W. Biederman
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02[PATCH] proc: remove the useless SMP-safe comments from /procEric W. Biederman
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02[PATCH] proc: remove trailing blank entry from pid_entry arraysEric W. Biederman
It was pointed out that since I am taking ARRAY_SIZE anyway the trailing empty entry is silly and just wastes space. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02[PATCH] proc: properly compute TGID_OFFSETEric W. Biederman
The value doesn't change but this ensures I will have the proper value when other files are added to proc_base_stuff. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02[PATCH] proc: Use pid_task instead of open coding itEric W. Biederman
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02[PATCH] proc: Merge proc_tid_attr and proc_tgid_attrEric W. Biederman
The implementation is exactly the same and there is currently nothing to distinguish proc_tid_attr, and proc_tgid_attr. So it is pointless to have two separate implementations. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02[PATCH] proc: Remove the hard coded inode numbersEric W. Biederman
The hard coded inode numbers in proc currently limit its maintainability, its flexibility, and what can be done with the rest of system. /proc limits pid-max to 32768 on 32 bit systems it limits fd-max to 32768 on all systems, and placing the pid in the inode number really gets in the way of implementing subdirectories of per process information. Ever since people started adding to the middle of the file type enumeration we haven't been maintaing the historical inode numbers, all we have really succeeded in doing is keeping the pid in the proc inode number. The pid is already available in the directory name so no information is lost removing it from the inode number. So if something in user space cares if we remove the inode number from the /proc inode it is almost certainly broken. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02[PATCH] proc: Factor out an instantiate method from every lookup methodEric W. Biederman
To remove the hard coded proc inode numbers it is necessary to be able to create the proc inodes during readdir. The instantiate methods are the subset of lookup that is needed to accomplish that. This first step just splits the lookup methods into 2 functions. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02[PATCH] proc: Make the generation of the self symlink table drivenEric W. Biederman
This patch generalizes the concept of files in /proc that are related to processes but live in the root directory of /proc Ideally this would reuse infrastructure from the rest of the process specific parts of proc but unfortunately security_task_to_inode must not be called on files that are not strictly per process. security_task_to_inode really needs to be reexamined as the security label can change in important places that we are not currently catching, but I'm not certain that simplifies this problem. By at least matching the structure of the rest of proc we get more idiom reuse and it becomes easier to spot problems in the way things are put together. Later things like /proc/mounts are likely to be moved into proc_base as well. If union mounts are ever supported we may be able to make /proc a union mount, and properly split it into 2 filesystems. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02[PATCH] namespaces: incorporate fs namespace into nsproxySerge E. Hallyn
This moves the mount namespace into the nsproxy. The mount namespace count now refers to the number of nsproxies point to it, rather than the number of tasks. As a result, the unshare_namespace() function in kernel/fork.c no longer checks whether it is being shared. Signed-off-by: Serge Hallyn <serue@us.ibm.com> Cc: Kirill Korotaev <dev@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Andrey Savochkin <saw@sw.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02[PATCH] proc: modify proc_pident_lookup to be completely table drivenEric W. Biederman
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: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02[PATCH] proc: reorder the functions in base.cEric W. Biederman
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: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02[PATCH] proc: readdir race fix (take 3)Eric W. Biederman
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: Eric W. Biederman <ebiederm@xmission.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Jean Delvare <jdelvare@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29[PATCH] fix mem_write() return valueFrederik Deweerdt
At the beginning of the routine, "copied" is set to 0, but it is no good because in lines 805 and 812 it is set to other values. Finally, the routine returns as if it copied 12 (=ENOMEM) bytes less than it actually did. Signed-off-by: Frederik Deweerdt <frederik.deweerdt@gmail.com> Acked-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-15Don't allow chmod() on the /proc/<pid>/ filesLinus Torvalds
This just turns off chmod() on the /proc/<pid>/ files, since there is no good reason to allow it, and had we disallowed it originally, the nasty /proc race exploit wouldn't have been possible. The other patches already fixed the problem chmod() could cause, so this is really just some final mop-up.. This particular version is based off a patch by Eugene and Marcel which had much better naming than my original equivalent one. Signed-off-by: Eugene Teo <eteo@redhat.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-14Relax /proc fix a bitLinus Torvalds
Clearign all of i_mode was a bit draconian. We only really care about S_ISUID/ISGID, after all. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-14Fix nasty /proc vulnerabilityLinus Torvalds
We have a bad interaction with both the kernel and user space being able to change some of the /proc file status. This fixes the most obvious part of it, but I expect we'll also make it harder for users to modify even their "own" files in /proc. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-26[PATCH] SELinux: Add sockcreate node to procattr APIEric Paris
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: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] cleanup next_tid()Oleg Nesterov
Try to make next_tid() a bit more readable and deletes unnecessary "pid_alive(pos)" check. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] simplify/fix first_tid()Oleg Nesterov
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: Oleg Nesterov <oleg@tv-sign.ru> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Remove tasklist_lock from proc_task_readdir.Eric W. Biederman
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: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Cleanup proc_fd_access_allowedEric W. Biederman
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: Eric W. Biederman <ebiederm@xmission.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Chris Wright <chrisw@sous-sol.org> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Use sane permission checks on the /proc/<pid>/fd/ symlinksEric W. Biederman
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: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: optimize proc_check_dentry_visibleEric W. Biederman
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: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Use struct pid not struct task_refEric W. Biederman
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: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: don't lock task_structs indefinitelyEric W. Biederman
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: Eric W. Biederman <ebiederm@xmission.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Paul Jackson <pj@sgi.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Albert Cahalan <acahalan@gmail.com> Signed-off-by: Prasanna Meda <mlp@google.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: make PROC_NUMBUF the buffer size for holding integers as stringsEric W. Biederman
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: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] simply fix first_tgidEric W. Biederman
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: Eric W. Biederman <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Remove tasklist_lock from proc_pid_lookup() and proc_task_lookup()Eric W. Biederman
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: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Remove tasklist_lock from proc_pid_readdirEric W. Biederman
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: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: refactor reading directories of tasksEric W. Biederman
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: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Close the race of a process dying durning lookupEric W. Biederman
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: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Rewrite the proc dentry flush on exit optimizationEric W. Biederman
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: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Move proc_maps_operations into task_mmu.cEric W. Biederman
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: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Fix the link count for /proc/<pid>/taskEric W. Biederman
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: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Properly filter out files that are not visible to a processEric W. Biederman
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: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Kill proc_mem_inode_operationsEric W. Biederman
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: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Remove bogus proc_task_permissionEric W. Biederman
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: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Replace proc_inode.type with proc_inode.fdEric W. Biederman
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: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Simplify the ownership rules for /procEric W. Biederman
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: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Remove unnecessary and misleading assignments from ↵Eric W. Biederman
proc_pid_make_inode 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: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Remove useless BKL in proc_pid_readlinkEric W. Biederman
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: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] proc: Fix the .. inode number on /proc/<pid>/fdEric W. Biederman
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] keys: add a way to store the appropriate context for newly-created keysMichael LeMay
Add a /proc/<pid>/attr/keycreate entry that stores the appropriate context for newly-created keys. Modify the selinux_key_alloc hook to make use of the new entry. Update the flask headers to include a new "setkeycreate" permission for processes. Update the flask headers to include a new "create" permission for keys. Use the create permission to restrict which SIDs each task can assign to newly-created keys. Add a new parameter to the security hook "security_key_alloc" to indicate whether it is being invoked by the kernel, or from userspace. If it is being invoked by the kernel, the security hook should never fail. Update the documentation to reflect these changes. Signed-off-by: Michael LeMay <mdlemay@epoch.ncsc.mil> Signed-off-by: James Morris <jmorris@namei.org> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-20[PATCH] proc_loginuid_write() uses simple_strtoul() on non-terminated arrayAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-04-19[PATCH] Fix file lookup without refDipankar Sarma
There are places in the kernel where we look up files in fd tables and access the file structure without holding refereces to the file. So, we need special care to avoid the race between looking up files in the fd table and tearing down of the file in another CPU. Otherwise, one might see a NULL f_dentry or such torn down version of the file. This patch fixes those special places where such a race may happen. Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com> Acked-by: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31[PATCH] cleanup in proc_check_chroot()Herbert Poetzl
proc_check_chroot() does the check in a very unintuitive way (keeping a copy of the argument, then modifying the argument), and has uncommented sideeffects. Signed-off-by: Herbert Poetzl <herbert@13thfloor.at> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-20VFS: New /proc file /proc/self/mountstatsChuck Lever
Create a new file under /proc/self, called mountstats, where mounted file systems can export information (configuration options, performance counters, and so on). Use a mechanism similar to /proc/mounts and s_ops->show_options. This mechanism does not violate namespace security, and is safe to use while other processes are unmounting file systems. Thanks to Mike Waychison for his review and comments. Test-plan: Test concurrent mount/unmount operations while cat'ing /proc/self/mountstats. Signed-off-by: Chuck Lever <cel@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>