From 490dea45d00f01847ebebd007685d564aaf2cd98 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 24 Nov 2008 17:06:57 +0100 Subject: itimers: remove the per-cpu-ish-ness Either we bounce once cacheline per cpu per tick, yielding n^2 bounces or we just bounce a single.. Also, using per-cpu allocations for the thread-groups complicates the per-cpu allocator in that its currently aimed to be a fixed sized allocator and the only possible extention to that would be vmap based, which is seriously constrained on 32 bit archs. So making the per-cpu memory requirement depend on the number of processes is an issue. Lastly, it didn't deal with cpu-hotplug, although admittedly that might be fixable. Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar --- kernel/fork.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) (limited to 'kernel/fork.c') diff --git a/kernel/fork.c b/kernel/fork.c index 7b8f2a78be3d..7087d8c0e5e2 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -820,14 +820,15 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) int ret; if (clone_flags & CLONE_THREAD) { - ret = thread_group_cputime_clone_thread(current); - if (likely(!ret)) { - atomic_inc(¤t->signal->count); - atomic_inc(¤t->signal->live); - } - return ret; + atomic_inc(¤t->signal->count); + atomic_inc(¤t->signal->live); + return 0; } sig = kmem_cache_alloc(signal_cachep, GFP_KERNEL); + + if (sig) + posix_cpu_timers_init_group(sig); + tsk->signal = sig; if (!sig) return -ENOMEM; @@ -864,8 +865,6 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) memcpy(sig->rlim, current->signal->rlim, sizeof sig->rlim); task_unlock(current->group_leader); - posix_cpu_timers_init_group(sig); - acct_init_pacct(&sig->pacct); tty_audit_fork(sig); -- cgit v1.2.3 From 783adf42cf039083dd3c734c07c3bdc707e2bb15 Mon Sep 17 00:00:00 2001 From: Steven Noonan Date: Sun, 11 Jan 2009 01:04:21 -0800 Subject: kernel/fork.c: unused variable 'ret' Removed the unused variable. Signed-off-by: Steven Noonan Signed-off-by: Ingo Molnar --- kernel/fork.c | 1 - 1 file changed, 1 deletion(-) (limited to 'kernel/fork.c') diff --git a/kernel/fork.c b/kernel/fork.c index e995899ea83f..81da4aae85cb 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -817,7 +817,6 @@ static void posix_cpu_timers_init_group(struct signal_struct *sig) static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) { struct signal_struct *sig; - int ret; if (clone_flags & CLONE_THREAD) { atomic_inc(¤t->signal->count); -- cgit v1.2.3 From 17da2bd90abf428523de0fb98f7075e00e3ed42e Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Wed, 14 Jan 2009 14:14:10 +0100 Subject: [CVE-2009-0029] System call wrappers part 08 Signed-off-by: Heiko Carstens --- kernel/fork.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/fork.c') diff --git a/kernel/fork.c b/kernel/fork.c index 1d68f1255dd8..8eb37d38c6a4 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -901,7 +901,7 @@ static void copy_flags(unsigned long clone_flags, struct task_struct *p) clear_freeze_flag(p); } -asmlinkage long sys_set_tid_address(int __user *tidptr) +SYSCALL_DEFINE1(set_tid_address, int __user *, tidptr) { current->clear_child_tid = tidptr; -- cgit v1.2.3 From 6559eed8ca7db0531a207cd80be5e28cd6f213c5 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Wed, 14 Jan 2009 14:14:32 +0100 Subject: [CVE-2009-0029] System call wrappers part 30 Signed-off-by: Heiko Carstens --- kernel/fork.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/fork.c') diff --git a/kernel/fork.c b/kernel/fork.c index 8eb37d38c6a4..bf0cef8bbdf2 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1603,7 +1603,7 @@ static int unshare_fd(unsigned long unshare_flags, struct files_struct **new_fdp * constructed. Here we are modifying the current, active, * task_struct. */ -asmlinkage long sys_unshare(unsigned long unshare_flags) +SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags) { int err = 0; struct fs_struct *fs, *new_fs = NULL; -- cgit v1.2.3 From 32bd671d6cbeda60dc73be77fa2b9037d9a9bfa0 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 5 Feb 2009 12:24:15 +0100 Subject: signal: re-add dead task accumulation stats. We're going to split the process wide cpu accounting into two parts: - clocks; which can take all the time they want since they run from user context. - timers; which need constant time tracing but can affort the overhead because they're default off -- and rare. The clock readout will go back to a full sum of the thread group, for this we need to re-add the exit stats that were removed in the initial itimer rework (f06febc9: timers: fix itimer/many thread hang). Furthermore, since that full sum can be rather slow for large thread groups and we have the complete dead task stats, revert the do_notify_parent time computation. Signed-off-by: Peter Zijlstra Reviewed-by: Ingo Molnar Signed-off-by: Ingo Molnar --- kernel/fork.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'kernel/fork.c') diff --git a/kernel/fork.c b/kernel/fork.c index 242a706e7721..e8e854a04ad2 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -851,13 +851,14 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) sig->tty_old_pgrp = NULL; sig->tty = NULL; - sig->cutime = sig->cstime = cputime_zero; + sig->utime = sig->stime = sig->cutime = sig->cstime = cputime_zero; sig->gtime = cputime_zero; sig->cgtime = cputime_zero; sig->nvcsw = sig->nivcsw = sig->cnvcsw = sig->cnivcsw = 0; sig->min_flt = sig->maj_flt = sig->cmin_flt = sig->cmaj_flt = 0; sig->inblock = sig->oublock = sig->cinblock = sig->coublock = 0; task_io_accounting_init(&sig->ioac); + sig->sum_sched_runtime = 0; taskstats_tgid_init(sig); task_lock(current->group_leader); -- cgit v1.2.3 From 04ec93fe9bc98e3bd8560f79f56fed66dfae40d5 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Fri, 6 Feb 2009 08:17:19 +0000 Subject: fork.c: fix NULL pointer dereference when nr_threads == threads-max I happened to forked lots of processes, and hit NULL pointer dereference. It is because in copy_process() after checking max_threads, 0 is returned but not -EAGAIN. The bug is introduced by "CRED: Detach the credentials from task_struct" (commit f1752eec6145c97163dbce62d17cf5d928e28a27). Signed-off-by: Li Zefan Signed-off-by: David Howells Acked-by: James Morris Signed-off-by: Linus Torvalds --- kernel/fork.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel/fork.c') diff --git a/kernel/fork.c b/kernel/fork.c index 242a706e7721..6d5dbb7a13e2 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1005,6 +1005,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, * triggers too late. This doesn't hurt, the check is only there * to stop root fork bombs. */ + retval = -EAGAIN; if (nr_threads >= max_threads) goto bad_fork_cleanup_count; -- cgit v1.2.3 From 06eb23b1ba39c61ee5d5faeb42a097635693e370 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Mon, 9 Feb 2009 02:02:33 +0100 Subject: ptrace, x86: fix the usage of ptrace_fork() I noticed by pure accident we have ptrace_fork() and friends. This was added by "x86, bts: add fork and exit handling", commit bf53de907dfdaac178c92d774aae7370d7b97d20. I can't test this, ds_request_bts() returns -EOPNOTSUPP, but I strongly believe this needs the fix. I think something like this program int main(void) { int pid = fork(); if (!pid) { ptrace(PTRACE_TRACEME, 0, NULL, NULL); kill(getpid(), SIGSTOP); fork(); } else { struct ptrace_bts_config bts = { .flags = PTRACE_BTS_O_ALLOC, .size = 4 * 4096, }; wait(NULL); ptrace(PTRACE_SETOPTIONS, pid, NULL, PTRACE_O_TRACEFORK); ptrace(PTRACE_BTS_CONFIG, pid, &bts, sizeof(bts)); ptrace(PTRACE_CONT, pid, NULL, NULL); sleep(1); } return 0; } should crash the kernel. If the task is traced by its natural parent ptrace_reparented() returns 0 but we should clear ->btsxxx anyway. Signed-off-by: Oleg Nesterov Acked-by: Markus Metzger Signed-off-by: Ingo Molnar --- kernel/fork.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/fork.c') diff --git a/kernel/fork.c b/kernel/fork.c index 242a706e7721..43c039d55e95 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1093,7 +1093,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, #ifdef CONFIG_DEBUG_MUTEXES p->blocked_on = NULL; /* not blocked yet */ #endif - if (unlikely(ptrace_reparented(current))) + if (unlikely(current->ptrace)) ptrace_fork(p, clone_flags); /* Perform scheduler related setup. Assign this task to a CPU. */ -- cgit v1.2.3