From 26ff6ad9786abf6f40a6d3cbb89753b4fa50cb00 Mon Sep 17 00:00:00 2001 From: Srivatsa Vaddagiri Date: Fri, 16 Sep 2005 19:27:40 -0700 Subject: [PATCH] CPU hotplug breaks wake_up_new_task Fix a problem wherein a new-born task is added to a dead CPU. Signed-off-by: Srivatsa Vaddagiri Acked-by: Nick Piggin Acked-by: Shaohua Li Acked-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/fork.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/fork.c b/kernel/fork.c index 8149f36028..533ce27f4b 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1062,7 +1062,8 @@ static task_t *copy_process(unsigned long clone_flags, * parent's CPU). This avoids alot of nasty races. */ p->cpus_allowed = current->cpus_allowed; - if (unlikely(!cpu_isset(task_cpu(p), p->cpus_allowed))) + if (unlikely(!cpu_isset(task_cpu(p), p->cpus_allowed) || + !cpu_online(task_cpu(p)))) set_task_cpu(p, smp_processor_id()); /* -- cgit v1.2.2 From 2030c0fd3db3332378f95f479c286181e3920644 Mon Sep 17 00:00:00 2001 From: Michael Kerrisk Date: Fri, 16 Sep 2005 19:28:02 -0700 Subject: [PATCH] PR_GET_DUMPABLE returns incorrect info 2.6.13 incorporated Alan Cox's patch for /proc/sys/fs/suid_dumpable (one version of this patch can be found here http://marc.theaimsgroup.com/?l=linux-kernel&m=109647550421014&w=2 ). This patch also made corresponding changes in kernel/sys.c to change the prctl() PR_SET_DUMPABLE operation so that the permitted range of 'arg2' was modified from 0..1 to 0..2. However, a corresponding change was not made for PR_GET_DUMPABLE: if the dumpable flag is non-zero, then PR_GET_DUMPABLE always returns 1, so that the caller can't determine the true setting of this flag. Acked-by: Alan Cox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/sys.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/sys.c b/kernel/sys.c index c80412be23..f723522e69 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1728,8 +1728,7 @@ asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3, error = put_user(current->pdeath_signal, (int __user *)arg2); break; case PR_GET_DUMPABLE: - if (current->mm->dumpable) - error = 1; + error = current->mm->dumpable; break; case PR_SET_DUMPABLE: if (arg2 < 0 || arg2 > 2) { -- cgit v1.2.2 From 4fb3a53860cee2aaaf81186c451b7da0b95b45c1 Mon Sep 17 00:00:00 2001 From: Dipankar Sarma Date: Fri, 16 Sep 2005 19:28:13 -0700 Subject: [PATCH] files: fix preemption issues With the new fdtable locking rules, you have to protect fdtable with either ->file_lock or rcu_read_lock/unlock(). There are some places where we aren't doing either. This patch fixes those places. Signed-off-by: Dipankar Sarma Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/exit.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'kernel') diff --git a/kernel/exit.c b/kernel/exit.c index 6d2089a1bc..ee6d8b8abe 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -371,6 +371,12 @@ static inline void close_files(struct files_struct * files) struct fdtable *fdt; j = 0; + + /* + * It is safe to dereference the fd table without RCU or + * ->file_lock because this is the last reference to the + * files structure. + */ fdt = files_fdtable(files); for (;;) { unsigned long set; -- cgit v1.2.2