From 5e876fb43dbf24c941a323139752bcb2f0a80da0 Mon Sep 17 00:00:00 2001 From: Sargun Dhillon Date: Tue, 7 Jan 2020 09:59:24 -0800 Subject: vfs, fdtable: Add fget_task helper This introduces a function which can be used to fetch a file, given an arbitrary task. As long as the user holds a reference (refcnt) to the task_struct it is safe to call, and will either return NULL on failure, or a pointer to the file, with a refcnt. This patch is based on Oleg Nesterov's (cf. [1]) patch from September 2018. [1]: Link: https://lore.kernel.org/r/20180915160423.GA31461@redhat.com Signed-off-by: Sargun Dhillon Suggested-by: Oleg Nesterov Acked-by: Christian Brauner Reviewed-by: Arnd Bergmann Link: https://lore.kernel.org/r/20200107175927.4558-2-sargun@sargun.me Signed-off-by: Christian Brauner --- include/linux/file.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/file.h b/include/linux/file.h index 3fcddff56bc4..c6c7b24ea9f7 100644 --- a/include/linux/file.h +++ b/include/linux/file.h @@ -16,6 +16,7 @@ extern void fput(struct file *); extern void fput_many(struct file *, unsigned int); struct file_operations; +struct task_struct; struct vfsmount; struct dentry; struct inode; @@ -47,6 +48,7 @@ static inline void fdput(struct fd fd) extern struct file *fget(unsigned int fd); extern struct file *fget_many(unsigned int fd, unsigned int refs); extern struct file *fget_raw(unsigned int fd); +extern struct file *fget_task(struct task_struct *task, unsigned int fd); extern unsigned long __fdget(unsigned int fd); extern unsigned long __fdget_raw(unsigned int fd); extern unsigned long __fdget_pos(unsigned int fd); -- cgit v1.2.3 From 9a2cef09c801de54feecd912303ace5c27237f12 Mon Sep 17 00:00:00 2001 From: Sargun Dhillon Date: Tue, 7 Jan 2020 09:59:26 -0800 Subject: arch: wire up pidfd_getfd syscall This wires up the pidfd_getfd syscall for all architectures. Signed-off-by: Sargun Dhillon Acked-by: Christian Brauner Reviewed-by: Arnd Bergmann Link: https://lore.kernel.org/r/20200107175927.4558-4-sargun@sargun.me Signed-off-by: Christian Brauner --- include/linux/syscalls.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 5262b7a76d39..8640af30c506 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -1000,6 +1000,7 @@ asmlinkage long sys_fspick(int dfd, const char __user *path, unsigned int flags) asmlinkage long sys_pidfd_send_signal(int pidfd, int sig, siginfo_t __user *info, unsigned int flags); +asmlinkage long sys_pidfd_getfd(int pidfd, int fd, unsigned int flags); /* * Architecture-specific system calls -- cgit v1.2.3 From 913292c97d750fe4188b4f5aa770e5e0ca1e5a91 Mon Sep 17 00:00:00 2001 From: Madhuparna Bhowmik Date: Fri, 24 Jan 2020 10:29:08 +0530 Subject: sched.h: Annotate sighand_struct with __rcu This patch fixes the following sparse errors by annotating the sighand_struct with __rcu kernel/fork.c:1511:9: error: incompatible types in comparison expression kernel/exit.c:100:19: error: incompatible types in comparison expression kernel/signal.c:1370:27: error: incompatible types in comparison expression This fix introduces the following sparse error in signal.c due to checking the sighand pointer without rcu primitives: kernel/signal.c:1386:21: error: incompatible types in comparison expression This new sparse error is also fixed in this patch. Signed-off-by: Madhuparna Bhowmik Acked-by: Paul E. McKenney Link: https://lore.kernel.org/r/20200124045908.26389-1-madhuparnabhowmik10@gmail.com Signed-off-by: Christian Brauner --- include/linux/sched.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/sched.h b/include/linux/sched.h index 467d26046416..ef60aa15097a 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -917,7 +917,7 @@ struct task_struct { /* Signal handlers: */ struct signal_struct *signal; - struct sighand_struct *sighand; + struct sighand_struct __rcu *sighand; sigset_t blocked; sigset_t real_blocked; /* Restored if set_restore_sigmask() was used: */ -- cgit v1.2.3