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* signalfd simplificationDavide Libenzi2007-09-20
| | | | | | | | | | | | | | | | | | | | This simplifies signalfd code, by avoiding it to remain attached to the sighand during its lifetime. In this way, the signalfd remain attached to the sighand only during poll(2) (and select and epoll) and read(2). This also allows to remove all the custom "tsk == current" checks in kernel/signal.c, since dequeue_signal() will only be called by "current". I think this is also what Ben was suggesting time ago. The external effect of this, is that a thread can extract only its own private signals and the group ones. I think this is an acceptable behaviour, in that those are the signals the thread would be able to fetch w/out signalfd. Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* exec: kill unsafe BUG_ON(sig->count) checksOleg Nesterov2007-08-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | de_thread: if (atomic_read(&oldsighand->count) <= 1) BUG_ON(atomic_read(&sig->count) != 1); This is not safe without the rmb() in between. The results of two correctly ordered __exit_signal()->atomic_dec_and_test()'s could be seen out of order on our CPU. The same is true for the "thread_group_empty()" case, __unhash_process()'s changes could be seen before atomic_dec_and_test(&sig->count). On some platforms (including i386) atomic_read() doesn't provide even the compiler barrier, in that case these checks are simply racy. Remove these BUG_ON()'s. Alternatively, we can do something like BUG_ON( ({ smp_rmb(); atomic_read(&sig->count) != 1; }) ); Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* signalfd: make it group-wide, fix posix-timers schedulingOleg Nesterov2007-08-22
| | | | | | | | | | | | | | | | | | | | | | | | With this patch any thread can dequeue its own private signals via signalfd, even if it was created by another sub-thread. To do so, we pass "current" to dequeue_signal() if the caller is from the same thread group. This also fixes the scheduling of posix timers broken by the previous patch. If the caller doesn't belong to this thread group, we can't handle __SI_TIMER case properly anyway. Perhaps we should forbid the cross-process signalfd usage and convert ctx->tsk to ctx->sighand. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Davide Libenzi <davidel@xmailserver.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Michael Kerrisk <mtk-manpages@gmx.net> Cc: Roland McGrath <roland@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Reset current->pdeath_signal on SUID binary executionMarcel Holtmann2007-08-18
| | | | | | | | | | | This fixes a vulnerability in the "parent process death signal" implementation discoverd by Wojciech Purczynski of COSEINC PTE Ltd. and iSEC Security Research. http://marc.info/?l=bugtraq&m=118711306802632&w=2 Signed-off-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* coredump masking: reimplementation of dumpable using two flagsKawai, Hidehiro2007-07-19
| | | | | | | | | | | | | | | | | This patch changes mm_struct.dumpable to a pair of bit flags. set_dumpable() converts three-value dumpable to two flags and stores it into lower two bits of mm_struct.flags instead of mm_struct.dumpable. get_dumpable() behaves in the opposite way. [akpm@linux-foundation.org: export set_dumpable] Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: David Howells <dhowells@redhat.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: variable length argument supportOllie Wild2007-07-19
| | | | | | | | | | | | | | | | | | | | | | Remove the arg+env limit of MAX_ARG_PAGES by copying the strings directly from the old mm into the new mm. We create the new mm before the binfmt code runs, and place the new stack at the very top of the address space. Once the binfmt code runs and figures out where the stack should be, we move it downwards. It is a bit peculiar in that we have one task with two mm's, one of which is inactive. [a.p.zijlstra@chello.nl: limit stack size] Signed-off-by: Ollie Wild <aaw@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: <linux-arch@vger.kernel.org> Cc: Hugh Dickins <hugh@veritas.com> [bunk@stusta.de: unexport bprm_mm_init] Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* audit: rework execve auditPeter Zijlstra2007-07-19
| | | | | | | | | | | | | | | | | | | | | | | The purpose of audit_bprm() is to log the argv array to a userspace daemon at the end of the execve system call. Since user-space hasn't had time to run, this array is still in pristine state on the process' stack; so no need to copy it, we can just grab it from there. In order to minimize the damage to audit_log_*() copy each string into a temporary kernel buffer first. Currently the audit code requires that the full argument vector fits in a single packet. So currently it does clip the argv size to a (sysctl) limit, but only when execve auditing is enabled. If the audit protocol gets extended to allow for multiple packets this check can be removed. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ollie Wild <aaw@google.com> Cc: <linux-audit@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uselib: add missing MNT_NOEXEC checkChristoph Hellwig2007-05-23
| | | | | | | | | | We don't allow loading ELF shared library from noexec points so the same should apply to sys_uselib aswell. Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Ulrich Drepper <drepper@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* make sysctl/kernel/core_pattern and fs/exec.c agree on maximum core filename ↵Dan Aloni2007-05-17
| | | | | | | | | | | | | size Make sysctl/kernel/core_pattern and fs/exec.c agree on maximum core filename size and change it to 128, so that extensive patterns such as '/local/cores/%e-%h-%s-%t-%p.core' won't result in truncated filename generation. Signed-off-by: Dan Aloni <da-x@monatomic.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'audit.b38' of ↵Linus Torvalds2007-05-11
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current * 'audit.b38' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current: [PATCH] Abnormal End of Processes [PATCH] match audit name data [PATCH] complete message queue auditing [PATCH] audit inode for all xattr syscalls [PATCH] initialize name osid [PATCH] audit signal recipients [PATCH] add SIGNAL syscall class (v3) [PATCH] auditing ptrace
| * [PATCH] Abnormal End of ProcessesSteve Grubb2007-05-11
| | | | | | | | | | | | | | | | | | | | | | | | | | Hi, I have been working on some code that detects abnormal events based on audit system events. One kind of event that we currently have no visibility for is when a program terminates due to segfault - which should never happen on a production machine. And if it did, you'd want to investigate it. Attached is a patch that collects these events and sends them into the audit system. Signed-off-by: Steve Grubb <sgrubb@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | signal/timer/event: signalfd coreDavide Libenzi2007-05-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch series implements the new signalfd() system call. I took part of the original Linus code (and you know how badly it can be broken :), and I added even more breakage ;) Signals are fetched from the same signal queue used by the process, so signalfd will compete with standard kernel delivery in dequeue_signal(). If you want to reliably fetch signals on the signalfd file, you need to block them with sigprocmask(SIG_BLOCK). This seems to be working fine on my Dual Opteron machine. I made a quick test program for it: http://www.xmailserver.org/signafd-test.c The signalfd() system call implements signal delivery into a file descriptor receiver. The signalfd file descriptor if created with the following API: int signalfd(int ufd, const sigset_t *mask, size_t masksize); The "ufd" parameter allows to change an existing signalfd sigmask, w/out going to close/create cycle (Linus idea). Use "ufd" == -1 if you want a brand new signalfd file. The "mask" allows to specify the signal mask of signals that we are interested in. The "masksize" parameter is the size of "mask". The signalfd fd supports the poll(2) and read(2) system calls. The poll(2) will return POLLIN when signals are available to be dequeued. As a direct consequence of supporting the Linux poll subsystem, the signalfd fd can use used together with epoll(2) too. The read(2) system call will return a "struct signalfd_siginfo" structure in the userspace supplied buffer. The return value is the number of bytes copied in the supplied buffer, or -1 in case of error. The read(2) call can also return 0, in case the sighand structure to which the signalfd was attached, has been orphaned. The O_NONBLOCK flag is also supported, and read(2) will return -EAGAIN in case no signal is available. If the size of the buffer passed to read(2) is lower than sizeof(struct signalfd_siginfo), -EINVAL is returned. A read from the signalfd can also return -ERESTARTSYS in case a signal hits the process. The format of the struct signalfd_siginfo is, and the valid fields depends of the (->code & __SI_MASK) value, in the same way a struct siginfo would: struct signalfd_siginfo { __u32 signo; /* si_signo */ __s32 err; /* si_errno */ __s32 code; /* si_code */ __u32 pid; /* si_pid */ __u32 uid; /* si_uid */ __s32 fd; /* si_fd */ __u32 tid; /* si_fd */ __u32 band; /* si_band */ __u32 overrun; /* si_overrun */ __u32 trapno; /* si_trapno */ __s32 status; /* si_status */ __s32 svint; /* si_int */ __u64 svptr; /* si_ptr */ __u64 utime; /* si_utime */ __u64 stime; /* si_stime */ __u64 addr; /* si_addr */ }; [akpm@linux-foundation.org: fix signalfd_copyinfo() on i386] Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | attach_pid() with struct pid parameterSukadev Bhattiprolu2007-05-11
|/ | | | | | | | | | | | | | attach_pid() currently takes a pid_t and then uses find_pid() to find the corresponding struct pid. Sometimes we already have the struct pid. We can then skip find_pid() if attach_pid() were to take a struct pid parameter. Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Serge Hallyn <serue@us.ibm.com> Cc: <containers@lists.osdl.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* (re)register_binfmt returns with -EBUSYkalash nainwal2007-05-08
| | | | | | | | | | | | | | | | | When a binary format is unregistered and re-registered, register_binfmt fails with -EBUSY. The reason is that unregister_binfmt does not set fmt->next to NULL, and seeing (fmt->next != NULL), register_binfmt fails with -EBUSY. One can find his way around by explicitly setting fmt->next to NULL after unregistering, but that is kind of unclean (one should better be using only the interfaces, and not the interal members, isn't it?) Attached one-liner can fix it. Signed-off-by: Kalash Nainwal <kalash.nainwal@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* exec: fix remove_arg_zeroNick Piggin2007-05-08
| | | | | | | | | | | | | | | | | | | | | | | | | | Petr Tesarik discovered a problem in remove_arg_zero(). He writes: When a script is loaded, load_script() replaces argv[0] with the name of the interpreter and the filename passed to the exec syscall. However, there is no guarantee that the length of the interpreter name plus the length of the filename is greater than the length of the original argv[0]. If the difference happens to cross a page boundary, setup_arg_pages() will call put_dirty_page() [aka install_arg_page()] with an address outside the VMA. Therefore, remove_arg_zero() must free all pages which would be unused after the argument is removed. So, rewrite the remove_arg_zero function without gotos, with a few comments, and with the commonly used explicit index/offset. This fixes the problem and makes it easier to understand as well. [a.p.zijlstra@chello.nl: add comment] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Petr Tesarik <ptesarik@suse.cz> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* exec.c: fix coredump to pipe problem and obscure "security hole"Alan Cox2007-04-17
| | | | | | | | | | | | | | | | The patch checks for "|" in the pattern not the output and doesn't nail a pid on to a piped name (as it is a program name not a file) Also fixes a very very obscure security corner case. If you happen to have decided on a core pattern that starts with the program name then the user can run a program called "|myevilhack" as it stands. I doubt anyone does this. Signed-off-by: Alan Cox <alan@redhat.com> Confirmed-by: Christopher S. Aker <caker@theshore.net> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] Transform kmem_cache_alloc()+memset(0) -> kmem_cache_zalloc().Robert P. J. Day2007-02-11
| | | | | | | | | | | | | | | | | | | | | | Replace appropriate pairs of "kmem_cache_alloc()" + "memset(0)" with the corresponding "kmem_cache_zalloc()" call. Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Andi Kleen <ak@muc.de> Cc: Roland McGrath <roland@redhat.com> Cc: James Bottomley <James.Bottomley@steeleye.com> Cc: Greg KH <greg@kroah.com> Acked-by: Joel Becker <Joel.Becker@oracle.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Jan Kara <jack@ucw.cz> Cc: Michael Halcrow <mhalcrow@us.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: James Morris <jmorris@namei.org> Cc: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] fdtable: Make fdarray and fdsets equal in sizeVadim Lobanov2006-12-10
| | | | | | | | | | | | | | | | | | | | | | | | Currently, each fdtable supports three dynamically-sized arrays of data: the fdarray and two fdsets. The code allows the number of fds supported by the fdarray (fdtable->max_fds) to differ from the number of fds supported by each of the fdsets (fdtable->max_fdset). In practice, it is wasteful for these two sizes to differ: whenever we hit a limit on the smaller-capacity structure, we will reallocate the entire fdtable and all the dynamic arrays within it, so any delta in the memory used by the larger-capacity structure will never be touched at all. Rather than hogging this excess, we shouldn't even allocate it in the first place, and keep the capacities of the fdarray and the fdsets equal. This patch removes fdtable->max_fdset. As an added bonus, most of the supporting code becomes simpler. Signed-off-by: Vadim Lobanov <vlobanov@speakeasy.net> Cc: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Dipankar Sarma <dipankar@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] add child reaper to pid_namespaceSukadev Bhattiprolu2006-12-08
| | | | | | | | | | | | | | | | | Add a per pid_namespace child-reaper. This is needed so processes are reaped within the same pid space and do not spill over to the parent pid space. Its also needed so containers preserve existing semantic that pid == 1 would reap orphaned children. This is based on Eric Biederman's patch: http://lkml.org/lkml/2006/2/6/285 Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Cedric Le Goater <clg@fr.ibm.com> Cc: Kirill Korotaev <dev@openvz.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] VFS: change struct file to use struct pathJosef "Jeff" Sipek2006-12-08
| | | | | | | | | | | | | This patch changes struct file to use struct path instead of having independent pointers to struct dentry and struct vfsmount, and converts all users of f_{dentry,vfsmnt} in fs/ to use f_path.{dentry,mnt}. Additionally, it adds two #define's to make the transition easier for users of the f_dentry and f_vfsmnt. Signed-off-by: Josef "Jeff" Sipek <jsipek@cs.sunysb.edu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] do_coredump() and not stopping rewrite attacks?Alexey Dobriyan2006-12-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On Sat, Dec 02, 2006 at 11:47:44PM +0300, Alexey Dobriyan wrote: > David Binderman compiled 2.6.19 with icc and grepped for "was set but never > used". Many warnings are on > http://coderock.org/kj/unused-2.6.19-fs Heh, the very first line: fs/exec.c(1465): remark #593: variable "flag" was set but never used fs/exec.c: 1477 /* 1478 * We cannot trust fsuid as being the "true" uid of the 1479 * process nor do we know its entire history. We only know it 1480 * was tainted so we dump it as root in mode 2. 1481 */ 1482 if (mm->dumpable == 2) { /* Setuid core dump mode */ 1483 flag = O_EXCL; /* Stop rewrite attacks */ 1484 current->fsuid = 0; /* Dump root private */ 1485 } And then filp_open follows with "flag" totally ignored. (akpm: this restores the code to Alan's original version. Andi's "Support piping into commands in /proc/sys/kernel/core_pattern" (cset d025c9db) broke it). Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: <stable@kerenl.org> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] slab: remove SLAB_KERNELChristoph Lameter2006-12-07
| | | | | | | | SLAB_KERNEL is an alias of GFP_KERNEL. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] namespaces: utsname: switch to using uts namespacesSerge E. Hallyn2006-10-02
| | | | | | | | | | | | | | | | | | | | | Replace references to system_utsname to the per-process uts namespace where appropriate. This includes things like uname. Changes: Per Eric Biederman's comments, use the per-process uts namespace for ELF_PLATFORM, sunrpc, and parts of net/ipv4/ipconfig.c [jdike@addtoit.com: UML fix] [clg@fr.ibm.com: cleanup] [akpm@osdl.org: build fix] Signed-off-by: Serge E. 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: Cedric Le Goater <clg@fr.ibm.com> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Support piping into commands in /proc/sys/kernel/core_patternAndi Kleen2006-10-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using the infrastructure created in previous patches implement support to pipe core dumps into programs. This is done by overloading the existing core_pattern sysctl with a new syntax: |program When the first character of the pattern is a '|' the kernel will instead threat the rest of the pattern as a command to run. The core dump will be written to the standard input of that program instead of to a file. This is useful for having automatic core dump analysis without filling up disks. The program can do some simple analysis and save only a summary of the core dump. The core dump proces will run with the privileges and in the name space of the process that caused the core dump. I also increased the core pattern size to 128 bytes so that longer command lines fit. Most of the changes comes from allowing core dumps without seeks. They are fairly straight forward though. One small incompatibility is that if someone had a core pattern previously that started with '|' they will get suddenly new behaviour. I think that's unlikely to be a real problem though. Additional background: > Very nice, do you happen to have a program that can accept this kind of > input for crash dumps? I'm guessing that the embedded people will > really want this functionality. I had a cheesy demo/prototype. Basically it wrote the dump to a file again, ran gdb on it to get a backtrace and wrote the summary to a shared directory. Then there was a simple CGI script to generate a "top 10" crashes HTML listing. Unfortunately this still had the disadvantage to needing full disk space for a dump except for deleting it afterwards (in fact it was worse because over the pipe holes didn't work so if you have a holey address map it would require more space). Fortunately gdb seems to be happy to handle /proc/pid/fd/xxx input pipes as cores (at least it worked with zsh's =(cat core) syntax), so it would be likely possible to do it without temporary space with a simple wrapper that calls it in the right way. I ran out of time before doing that though. The demo prototype scripts weren't very good. If there is really interest I can dig them out (they are currently on a laptop disk on the desk with the laptop itself being in service), but I would recommend to rewrite them for any serious application of this and fix the disk space problem. Also to be really useful it should probably find a way to automatically fetch the debuginfos (I cheated and just installed them in advance). If nobody else does it I can probably do the rewrite myself again at some point. My hope at some point was that desktops would support it in their builtin crash reporters, but at least the KDE people I talked too seemed to be happy with their user space only solution. Alan sayeth: I don't believe that piping as such as neccessarily the right model, but the ability to intercept and processes core dumps from user space is asked for by many enterprise users as well. They want to know about, capture, analyse and process core dumps, often centrally and in automated form. [akpm@osdl.org: loff_t != unsigned long] Signed-off-by: Andi Kleen <ak@suse.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] csa: convert CONFIG tag for extended accounting routinesJay Lan2006-10-01
| | | | | | | | | | | | | | | | | | There were a few accounting data/macros that are used in CSA but are #ifdef'ed inside CONFIG_BSD_PROCESS_ACCT. This patch is to change those ifdef's from CONFIG_BSD_PROCESS_ACCT to CONFIG_TASK_XACCT. A few defines are moved from kernel/acct.c and include/linux/acct.h to kernel/tsacct.c and include/linux/tsacct_kern.h. Signed-off-by: Jay Lan <jlan@sgi.com> Cc: Shailabh Nagar <nagar@watson.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Jes Sorensen <jes@sgi.com> Cc: Chris Sturtivant <csturtiv@sgi.com> Cc: Tony Ernst <tee@sgi.com> Cc: Guillaume Thouvenin <guillaume.thouvenin@bull.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Fix unserialized task->files changingKirill Korotaev2006-09-29
| | | | | | | | | | | | | | | | | Fixed race on put_files_struct on exec with proc. Restoring files on current on error path may lead to proc having a pointer to already kfree-d files_struct. ->files changing at exit.c and khtread.c are safe as exit_files() makes all things under lock. Found during OpenVZ stress testing. [akpm@osdl.org: add export] Signed-off-by: Pavel Emelianov <xemul@openvz.org> Signed-off-by: Kirill Korotaev <dev@openvz.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] de_thread: Use tsk not currentEric W. Biederman2006-09-27
| | | | | | | | | | | | | Ingo Oeser pointed out that because current expands to an inline function it is more space efficient and somewhat faster to simply keep a cached copy of current in another variable. This patch implements that for the de_thread function. (akpm: saves nearly 100 bytes of text on x86) 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>
* [PATCH] pid: Implement transfer_pid and use it to simplify de_threadEric W. Biederman2006-09-27
| | | | | | | | | | | | | | | | | | | In de_thread we move pids from one process to another, a rather ugly case. The function transfer_pid makes it clear what we are doing, and makes the action atomic. This is useful we ever want to atomically traverse the process group and session lists, in a rcu safe manner. Even if the atomic properties this change should be a win as transfer_pid should be less code to execute than executing both attach_pid and detach_pid, and this should make de_thread slightly smaller as only a single function call needs to be emitted. The only downside is that the code might be slower to execute as the odds are against transfer_pid being in cache. 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>
* [PATCH] fix up lockdep trace in fs/exec.cDave Jones2006-08-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes the locking error noticed by lockdep: ============================================= [ INFO: possible recursive locking detected ] --------------------------------------------- init/1 is trying to acquire lock: (&sighand->siglock){....}, at: [<c047a78a>] flush_old_exec+0x3ae/0x859 but task is already holding lock: (&sighand->siglock){....}, at: [<c047a77a>] flush_old_exec+0x39e/0x859 other info that might help us debug this: 2 locks held by init/1: #0: (tasklist_lock){..--}, at: [<c047a76a>] flush_old_exec+0x38e/0x859 #1: (&sighand->siglock){....}, at: [<c047a77a>] flush_old_exec+0x39e/0x859 stack backtrace: [<c04051e1>] show_trace_log_lvl+0x54/0xfd [<c040579d>] show_trace+0xd/0x10 [<c04058b6>] dump_stack+0x19/0x1b [<c043b33a>] __lock_acquire+0x773/0x997 [<c043bacf>] lock_acquire+0x4b/0x6c [<c060630b>] _spin_lock+0x19/0x28 [<c047a78a>] flush_old_exec+0x3ae/0x859 [<c0498053>] load_elf_binary+0x4aa/0x1628 [<c0479cab>] search_binary_handler+0xa7/0x24e [<c047b577>] do_execve+0x15b/0x1f9 [<c04022b4>] sys_execve+0x29/0x4d [<c0403faf>] syscall_call+0x7/0xb Signed-off-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* VFS: Remove redundant open-coded mode bit checks in open_exec().Trond Myklebust2006-08-24
| | | | | | | | The check in open_exec() for inode->i_mode & 0111 has been made redundant by the fix to permission(). Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> (cherry picked from 1d3741c5d991686699f100b65b9956f7ee7ae0ae commit)
* VFS: Remove redundant open-coded mode bit check in prepare_binfmt().Trond Myklebust2006-08-24
| | | | | | | | The check in prepare_binfmt() for inode->i_mode & 0111 is redundant, since open_exec() will already have done that. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> (cherry picked from 822dec482ced07af32c378cd936d77345786572b commit)
* Remove obsolete #include <linux/config.h>Jörn Engel2006-06-30
| | | | | Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* [PATCH] coredump: shutdown current process firstOleg Nesterov2006-06-26
| | | | | | | | | | | | | | | 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: Oleg Nesterov <oleg@tv-sign.ru> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] coredump: some code relocationsOleg Nesterov2006-06-26
| | | | | | | | | | | | 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: Oleg Nesterov <oleg@tv-sign.ru> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] coredump: don't take tasklist_lockOleg Nesterov2006-06-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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, &current->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: 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>
* [PATCH] coredump: kill ptrace related stuffOleg Nesterov2006-06-26
| | | | | | | | | | | | | | | | | | | | 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: Oleg Nesterov <oleg@tv-sign.ru> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] coredump: speedup SIGKILL sendingOleg Nesterov2006-06-26
| | | | | | | | | | | | 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: Oleg Nesterov <oleg@tv-sign.ru> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] coredump: optimize ->mm users traversalOleg Nesterov2006-06-26
| | | | | | | | | | | | | | | | 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: Oleg Nesterov <oleg@tv-sign.ru> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] de_thread: fix lockless do_each_threadOleg Nesterov2006-06-26
| | | | | | | | | | 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: 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>
* [PATCH] proc: Rewrite the proc dentry flush on exit optimizationEric W. Biederman2006-06-26
| | | | | | | | | | | | | | | | 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>
* [PATCH] remove steal_locks()Miklos Szeredi2006-06-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch removes the steal_locks() function. steal_locks() doesn't work correctly with any filesystem that does it's own lock management, including NFS, CIFS, etc. In addition it has weird semantics on local filesystems in case tasks sharing file-descriptor tables are doing POSIX locking operations in parallel to execve(). The steal_locks() function has an effect on applications doing: clone(CLONE_FILES) /* in child */ lock execve lock POSIX locks acquired before execve (by "child", "parent" or any further task sharing files_struct) will after the execve be owned exclusively by "child". According to Chris Wright some LSB/LTP kind of suite triggers without the stealing behavior, but there's no known real-world application that would also fail. Apps using NPTL are not affected, since all other threads are killed before execve. Apps using LinuxThreads are only affected if they - have multiple threads during exec (LinuxThreads doesn't kill other threads, the app may do it with pthread_kill_other_threads_np()) - rely on POSIX locks being inherited across exec Both conditions are documented, but not their interaction. Apps using clone() natively are affected if they - use clone(CLONE_FILES) - rely on POSIX locks being inherited across exec The above scenarios are unlikely, but possible. If the patch is vetoed, there's a plan B, that involves mostly keeping the weird stealing semantics, but changing the way lock ownership is handled so that network and local filesystems work consistently. That would add more complexity though, so this solution seems to be preferred by most people. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Matthew Wilcox <willy@debian.org> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Steven French <sfrench@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] execve argument loggingAl Viro2006-06-20
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [PATCH] task: Make task list manipulations RCU safeEric W. Biederman2006-04-19
| | | | | | | | | | | | | | | | | While we can currently walk through thread groups, process groups, and sessions with just the rcu_read_lock, this opens the door to walking the entire task list. We already have all of the other RCU guarantees so there is no cost in doing this, this should be enough so that proc can stop taking the tasklist lock during readdir. prev_task was killed because it has no users, and using it will miss new tasks when doing an rcu traversal. 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>
* [PATCH] de_thread: Don't change our parents and ptrace flags.Eric W. Biederman2006-04-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is two distinct changes. - Not changing our real parents. - Not changing our ptrace parents. Not changing our real parents is trivially correct because both tasks have the same real parents as they are part of a thread group. Now that we demote the leader to a thread there is no longer any reason to change it's parentage. Not changing our ptrace parents is a user visible change if someone looks hard enough. I don't think user space applications will care or even notice. In the practical and I think common case a debugger will have attached to all of the threads using the same ptrace flags. From my quick skim of strace and gdb that appears to be the case. Which if true means debuggers will not notice a change. Before this point we have already generated a ptrace event in do_exit that reports the leaders pid has died so de_thread is visible to a debugger. Which means attempting to hide this case by copying flags around appears excessive. By not doing anything it avoids all of the weird locking issues between de_thread and ptrace attach, and removes one case from consideration for fixing the ptrace locking. This only addresses Oleg's first concern with ptrace_attach, that of the problems caused by reparenting. Oleg's second concern is essentially a race between ptrace_attach and release_task that causes an oops when we get to force_sig_specific. There is nothing special about de_thread with respect to that race. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] process accounting: take original leader's start_time in non-leader execRoland McGrath2006-04-11
| | | | | | | | | | | | | | | The only record we have of the real-time age of a process, regardless of execs it's done, is start_time. When a non-leader thread exec, the original start_time of the process is lost. Things looking at the real-time age of the process are fooled, for example the process accounting record when the process finally dies. This change makes the oldest start_time stick around with the process after a non-leader exec. This way the association between PID and start_time is kept constant, which seems correct to me. Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] de_thread: Don't confuse users do_each_thread.Eric W. Biederman2006-04-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Oleg Nesterov spotted two interesting bugs with the current de_thread code. The simplest is a long standing double decrement of __get_cpu_var(process_counts) in __unhash_process. Caused by two processes exiting when only one was created. The other is that since we no longer detach from the thread_group list it is possible for do_each_thread when run under the tasklist_lock to see the same task_struct twice. Once on the task list as a thread_group_leader, and once on the thread list of another thread. The double appearance in do_each_thread can cause a double increment of mm_core_waiters in zap_threads resulting in problems later on in coredump_wait. To remedy those two problems this patch takes the simple approach of changing the old thread group leader into a child thread. The only routine in release_task that cares is __unhash_process, and it can be trivially seen that we handle cleaning up a thread group leader properly. Since de_thread doesn't change the pid of the exiting leader process and instead shares it with the new leader process. I change thread_group_leader to recognize group leadership based on the group_leader field and not based on pids. This should also be slightly cheaper then the existing thread_group_leader macro. I performed a quick audit and I couldn't see any user of thread_group_leader that cared about the difference. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* BUG_ON() Conversion in fs/exec.cEric Sesterhenn2006-03-31
| | | | | | | | this changes if() BUG(); constructs to BUG_ON() which is cleaner and can better optimized away Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* [PATCH] convert sighand_cache to use SLAB_DESTROY_BY_RCUOleg Nesterov2006-03-28
| | | | | | | | | | | | | | | | | | This patch borrows a clever Hugh's 'struct anon_vma' trick. Without tasklist_lock held we can't trust task->sighand until we locked it and re-checked that it is still the same. But this means we don't need to defer 'kmem_cache_free(sighand)'. We can return the memory to slab immediately, all we need is to be sure that sighand->siglock can't dissapear inside rcu protected section. To do so we need to initialize ->siglock inside ctor function, SLAB_DESTROY_BY_RCU does the rest. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] remove add_parent()'s parent argumentOleg Nesterov2006-03-28
| | | | | | | | | | | | add_parent(p, parent) is always called with parent == p->parent, and it makes no sense to do it differently. This patch removes this argument. No changes in affected .o files. 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>
* [PATCH] pidhash: kill switch_exec_pidsEric W. Biederman2006-03-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | switch_exec_pids is only called from de_thread by way of exec, and it is only called when we are exec'ing from a non thread group leader. Currently switch_exec_pids gives the leader the pid of the thread and unhashes and rehashes all of the process groups. The leader is already in the EXIT_DEAD state so no one cares about it's pids. The only concern for the leader is that __unhash_process called from release_task will function correctly. If we don't touch the leader at all we know that __unhash_process will work fine so there is no need to touch the leader. For the task becomming the thread group leader, we just need to give it the pid of the old thread group leader, add it to the task list, and attach it to the session and the process group of the thread group. Currently de_thread is also adding the task to the task list which is just silly. Currently the only leader of __detach_pid besides detach_pid is switch_exec_pids because of the ugly extra work that was being performed. So this patch removes switch_exec_pids because it is doing too much, it is creating an unnecessary special case in pid.c, duing work duplicated in de_thread, and generally obscuring what it is going on. The necessary work is added to de_thread, and it seems to be a little clearer there what is going on. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Kirill Korotaev <dev@sw.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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