- 08 Feb, 2008 40 commits
-
-
Oleg Nesterov authored
Surprise, the other two wait_task_*() functions also abuse the task_pid_nr_ns() function, and may cause read-after-free or report nr == 0 in wait_task_continued(). wait_task_zombie() doesn't have this problem, but it is still better to cache pid_t rather than call task_pid_nr_ns() three times on the saved pid_namespace. Signed-off-by:
Oleg Nesterov <oleg@tv-sign.ru> Cc: Roland McGrath <roland@redhat.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
-
Oleg Nesterov authored
Imho, the current usage of security_task_wait() is not logical. Suppose we have the single child p, and security_task_wait(p) return -EANY. In that case waitpid(-1) returns this error. Why? Isn't it better to return ECHLD? We don't really have reapable children. Now suppose that child was stolen by gdb. In that case we find this child on ->ptrace_children and set flag = 1, but we don't check that the child was denied. So, do_wait(..., WNOHANG) returns 0, this doesn't match the behaviour above. Without WNOHANG do_wait() blocks only to return the error later, when the child will be untraced. Inho, really strange. I think eligible_child() should return the error only if the child's pid was requested explicitly, otherwise we should silently ignore the tasks which were nacked by security_task_wait(). Signed-off-by:
-
Oleg Nesterov authored
eligible_child() == 2 means delay_group_leader(). With the previous patch this only matters for EXIT_ZOMBIE task, we can move that special check to the only place it is really needed. Also, with this patch we don't skip security_task_wait() for the group leaders in a non-empty thread group. I don't really understand the exact semantics of security_task_wait(), but imho this change is a bugfix. Also rearrange the code a bit to kill an ugly "check_continued" backdoor. Signed-off-by:
-
Oleg Nesterov authored
wait_task_stopped() doesn't need the "delay_group_leader" parameter. If the child is not traced it must be a group leader. With or without subthreads ->group_stop_count == 0 when the whole task is stopped. Signed-off-by:
Roland McGrath <roland@redhat.com> Signed-off-by:
-
Oleg Nesterov authored
If the tracer is gone and we are not going to stop, ptrace_stop() sets ->exit_code = nostop_code. However, the tracer could actually clear the exit code before detaching. In that case get_signal_to_deliver() "resends" the signal which was cancelled by the debugger. For example, it is possible that a quick PTRACE_ATTACH + PTRACE_DETACH can leave the tracee in STOPPED state. Change the behaviour of ptrace_stop(). If the caller is ptrace notify(), we should always clear ->exit_code. If the caller is get_signal_to_deliver(), we should not touch it at all. To do so, change the nonstop_code parameter to "bool clear_code" and change the callers accordingly. Signed-off-by:
-
Oleg Nesterov authored
Every branch if the main "if" statement does the same code at the end. Move it down. Also, fix the indentation. Signed-off-by:
-
Oleg Nesterov authored
wait_task_stopped() has multiple races with SIGCONT/SIGKILL. tasklist_lock does not pin the child in TASK_TRACED/TASK_STOPPED stated, almost all info reported (including exit_code) may be wrong. In fact, the code under write_lock_irq(tasklist_lock) is not safe. The child may be PTRACE_DETACH'ed at this time by another subthread, in that case it is possible we are no longer its ->parent. Change wait_task_stopped() to take ->siglock before inspecting the task. This guarantees that the child can't resume and (for example) clear its ->exit_code, so we don't need to use xchg(&p->exit_code) and re-check. The only exception is ptrace_stop() which changes ->state and ->exit_code without ->siglock held during abort. But this can only happen if both the tracer and the tracee are dying (coredump is in progress), we don't care. With this patch wait_task_stopped() doesn't move the child to the end of the ->parent list on success. This optimization could be restored, but in that case we have to take write_lock(tasklist) and do some nasty checks. Also change the do_wait() since we don't return EAGAIN any longer. [akpm@linux-foundation.org: fix up after Willy renamed everything] Signed-off-by:
-
Oleg Nesterov authored
If the tracer went away (may_ptrace_stop() failed), ptrace_stop() drops tasklist and then changes the ->state from TASK_TRACED to TASK_RUNNING. This can fool another tracer which attaches to us in between. Change the ->state under tasklist_lock to ensure that ptrace_check_attach() can't wrongly succeed. Also, remove the unnecessary mb(). Signed-off-by:
-
Oleg Nesterov authored
It is not possible to see the PT_PTRACED task without ->signal/sighand under tasklist_lock, release_task() does ptrace_unlink() first. If the task was already released before, ptrace_attach() can't succeed and set PT_PTRACED. Remove this check. Signed-off-by:
-
Oleg Nesterov authored
Now that my_ptrace_child() is trivial we can use the "p->ptrace & PT_PTRACED" inline and simplify the corresponding logic in do_wait: we can't find the child in TASK_TRACED state without PT_PTRACED flag set, ptrace_untrace() either sets TASK_STOPPED or wakes up the tracee. Signed-off-by:
-
Oleg Nesterov authored
Since the patch "Fix ptrace_attach()/ptrace_traceme()/de_thread() race" commit f5b40e36 we set PT_ATTACHED and change child->parent "atomically" wrt task_list lock. This means we can remove the checks like "PT_ATTACHED && ->parent != ptracer" which were needed to catch the "ptrace attach is in progress" case. We can also remove the flag itself since nobody else uses it. Signed-off-by:
-
Pierre Peiffer authored
sem_exit_ns(), msg_exit_ns() and shm_exit_ns() are all called when an ipc_namespace is released to free all ipcs of each type. But in fact, they do the same thing: they loop around all ipcs to free them individually by calling a specific routine. This patch proposes to consolidate this by introducing a common function, free_ipcs(), that do the job. The specific routine to call on each individual ipcs is passed as parameter. For this, these ipc-specific 'free' routines are reworked to take a generic 'struct ipc_perm' as parameter. Signed-off-by:
Pierre Peiffer <pierre.peiffer@bull.net> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by:
-
Pierre Peiffer authored
Each ipc_namespace contains a table of 3 pointers to struct ipc_ids (3 for msg, sem and shm, structure used to store all ipcs) These 'struct ipc_ids' are dynamically allocated for each icp_namespace as the ipc_namespace itself (for the init namespace, they are initialized with pointers to static variables instead) It is so for historical reason: in fact, before the use of idr to store the ipcs, the ipcs were stored in tables of variable length, depending of the maximum number of ipc allowed. Now, these 'struct ipc_ids' have a fixed size. As they are allocated in any cases for each new ipc_namespace, there is no gain of memory in having them allocated separately of the struct ipc_namespace. This patch proposes to make this table static in the struct ipc_namespace. Thus, we can allocate all in once and get rid of all the code needed to allocate and free these ipc_ids separately. Signed-off-by:
Cedric Le Goater <clg@fr.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by:
-
Pierre Peiffer authored
These commands (SEM_STAT and IPC_STAT) are rather doing the same things (only the meaning of the id given as input and the return value differ). However, for the semaphores, they are handled in two different places (two different functions). This patch consolidates this for clarification by handling these both commands in the same place in semctl_nolock(). It also removes one unused parameter for this function. Signed-off-by:
-
Pavel Emelyanov authored
ipc_lock_check_down(), ipc_lock_check() and ipcget() seem too large to be inline. Besides, they give no optimization being inline as they perform calls inside in any case. Moving them into ipc/util.c saves 500 bytes of vmlinux and shortens IPC internal API. $ ./scripts/bloat-o-meter vmlinux-orig vmlinux add/remove: 3/2 grow/shrink: 0/10 up/down: 490/-989 (-499) function old new delta ipcget - 392 +392 ipc_lock_check_down - 49 +49 ipc_lock_check - 49 +49 sys_semget 119 105 -14 sys_shmget 108 86 -22 sys_msgget 100 78 -22 do_msgsnd 665 631 -34 do_msgrcv 680 644 -36 do_shmat 771 733 -38 sys_msgctl 1302 1229 -73 ipcget_new 80 - -80 sys_semtimedop 1534 1452 -82 sys_semctl 2034 1922 -112 sys_shmctl 1919 1765 -154 ipcget_public 322 - -322 The ipcget() growth is the result of gcc inlining of currently static ipcget_new/_public. Signed-off-by:
Pavel Emelyanov <xemul@openvz.org> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by:
-
Alan Cox authored
Signed-off-by:
Alan Cox <alan@redhat.com> Signed-off-by:
-
Alan Cox authored
Signed-off-by:
-
Alan Cox authored
Signed-off-by:
-
Alan Cox authored
Signed-off-by:
-
Alan Cox authored
Signed-off-by:
-
Alan Cox authored
Signed-off-by:
-
Alan Cox authored
Signed-off-by:
-
Alan Cox authored
Signed-off-by:
-
Alan Cox authored
Signed-off-by:
-
Alan Cox authored
Signed-off-by:
-
Alan Cox authored
Signed-off-by:
-
Alan Cox authored
Signed-off-by:
-
Alan Cox authored
Also removes a cflag comparison that caused some mode changes to get wrongly ignored Signed-off-by:
-
Alan Cox authored
Signed-off-by:
-
Alan Cox authored
Signed-off-by:
-
Andrew Morton authored
Get the constness right, avoid nasty cast. Cc: Ingo Molnar <mingo@elte.hu> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by:
-
Christoph Lameter authored
module.c should not define linker variables on its own. We have an include file for that. Signed-off-by:
Christoph Lameter <clameter@sgi.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by:
-
Christoph Lameter authored
The module subsystem cannot handle symbols that are zero. If symbols are present that have a zero value then the module resolver prints out a message that these symbols are unresolved. [akinobu.mita@gmail.com: fix __find_symbl() error checks] Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Kay Sievers <kay.sievers@vrfy.org Signed-off-by:
Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by:
-
Heiko Carstens authored
Backend for s390. Acked-by:
Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by:
Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by:
-
Heiko Carstens authored
Give architectures that support the new termios2 the possibilty to overide the user_termios_to_kernel_termios and kernel_termios_to_user_termios macros. As soon as all architectures that use the generic variant have been converted the ifdefs can go away again. Architectures in question are avr32, frv, powerpc and s390. Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Paul Mackerras <paulus@samba.org> Cc: David Howells <dhowells@redhat.com> Cc: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by:
-
mark gross authored
Fix an off by one bug in the fault reason string reporting function, and clean up some of the code around this buglet. [akpm@linux-foundation.org: cleanup] Signed-off-by:
mark gross <mgross@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andi Kleen <ak@suse.de> Signed-off-by:
-
mark gross authored
Add support for protected memory enable bits by clearing them if they are set at startup time. Some future boot loaders or firmware could have this bit set after it loads the kernel, and it needs to be cleared if DMA's are going to happen effectively. Signed-off-by:
mark gross <mgross@intel.com> Acked-by:
Muli Ben-Yehuda <muli@il.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andi Kleen <ak@suse.de> Signed-off-by:
-
Alexey Dobriyan authored
Typical PDE creation code looks like: pde = create_proc_entry("foo", 0, NULL); if (pde) pde->proc_fops = &foo_proc_fops; Notice that PDE is first created, only then ->proc_fops is set up to final value. This is a problem because right after creation a) PDE is fully visible in /proc , and b) ->proc_fops are proc_file_operations which do not have ->open callback. So, it's possible to ->read without ->open (see one class of oopses below). The fix is new API called proc_create() which makes sure ->proc_fops are set up before gluing PDE to main tree. Typical new code looks like: pde = proc_create("foo", 0, NULL, &foo_proc_fops); if (!pde) return -ENOMEM; Fix most networking users for a start. In the long run, create_proc_entry() for regular files will go. BUG: unable to handle kernel NULL pointer dereference at virtual address 00000024 printing eip: c1188c1b *pdpt = 000000002929e001 *pde = 0000000000000000 Oops: 0002 [#1] PREEMPT SMP DEBUG_PAGEALLOC last sysfs file: /sys/block/sda/sda1/dev Modules linked in: foo af_packet ipv6 cpufreq_ondemand loop serio_raw psmouse k8temp hwmon sr_mod cdrom Pid: 24679, comm: cat Not tainted (2.6.24-rc3-mm1 #2) EIP: 0060:[<c1188c1b>] EFLAGS: 00210002 CPU: 0 EIP is at mutex_lock_nested+0x75/0x25d EAX: 000006fe EBX: fffffffb ECX: 00001000 EDX: e9340570 ESI: 00000020 EDI: 00200246 EBP: e9340570 ESP: e8ea1ef8 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 Process cat (pid: 24679, ti=E8EA1000 task=E9340570 task.ti=E8EA1000) Stack: 00000000 c106f7ce e8ee05b4 00000000 00000001 458003d0 f6fb6f20 fffffffb 00000000 c106f7aa 00001000 c106f7ce 08ae9000 f6db53f0 00000020 00200246 00000000 00000002 00000000 00200246 00200246 e8ee05a0 fffffffb e8ee0550 Call Trace: [<c106f7ce>] seq_read+0x24/0x28a [<c106f7aa>] seq_read+0x0/0x28a [<c106f7ce>] seq_read+0x24/0x28a [<c106f7aa>] seq_read+0x0/0x28a [<c10818b8>] proc_reg_read+0x60/0x73 [<c1081858>] proc_reg_read+0x0/0x73 [<c105a34f>] vfs_read+0x6c/0x8b [<c105a6f3>] sys_read+0x3c/0x63 [<c10025f2>] sysenter_past_esp+0x5f/0xa5 [<c10697a7>] destroy_inode+0x24/0x33 ======================= INFO: lockdep is turned off. Code: 75 21 68 e1 1a 19 c1 68 87 00 00 00 68 b8 e8 1f c1 68 25 73 1f c1 e8 84 06 e9 ff e8 52 b8 e7 ff 83 c4 10 9c 5f fa e8 28 89 ea ff <f0> fe 4e 04 79 0a f3 90 80 7e 04 00 7e f8 eb f0 39 76 34 74 33 EIP: [<c1188c1b>] mutex_lock_nested+0x75/0x25d SS:ESP 0068:e8ea1ef8 [akpm@linux-foundation.org: coding-style fixes] Signed-off-by:Alexey Dobriyan <adobriyan@sw.ru> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by:
-
Eric W. Biederman authored
Long ago when the CLONE_THREAD support first went it someone thought it would be wise to point /proc/self at /proc/<tgid> instead of /proc/<pid>. Given that /proc/<tgid> can return information about a very different task (if enough things have been unshared) then our current process /proc/<tgid> seems blatantly wrong. So far I have yet to think up an example where the current behavior would be advantageous, and I can see several places where it is seriously non-intuitive. We may be stuck with the current broken behavior for backwards compatibility reasons but lets try fixing our ancient bug for the 2.6.25 time frame and see if anyone screams. Signed-off-by:
Eric W. Biederman <ebiederm@xmission.com> Acked-by:
Ingo Molnar <mingo@elte.hu> Cc: "Guillaume Chazarain" <guichaz@yahoo.fr> Cc: "Pavel Emelyanov" <xemul@openvz.org> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Roland McGrath <roland@redhat.com> Signed-off-by:
-
Eric W. Biederman authored
Currently if you access a /proc that is not mounted with your processes current pid namespace /proc/self will point at a completely random task. This patch fixes /proc/self to point to the current process if it is available in the particular mount of /proc or to return -ENOENT if the current process is not visible. Signed-off-by:
-
