From 1f702603e7125a390b5cdf5ce00539781cfcc86a Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 20 Nov 2020 17:14:19 -0600 Subject: exec: Simplify unshare_files Now that exec no longer needs to return the unshared files to their previous value there is no reason to return displaced. Instead when unshare_fd creates a copy of the file table, call put_files_struct before returning from unshare_files. Acked-by: Christian Brauner v1: https://lkml.kernel.org/r/20200817220425.9389-2-ebiederm@xmission.com Link: https://lkml.kernel.org/r/20201120231441.29911-2-ebiederm@xmission.com Signed-off-by: Eric W. Biederman --- include/linux/fdtable.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index a32bf47c593e..f46a084b60b2 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -109,7 +109,7 @@ struct task_struct; struct files_struct *get_files_struct(struct task_struct *); void put_files_struct(struct files_struct *fs); void reset_files_struct(struct files_struct *); -int unshare_files(struct files_struct **); +int unshare_files(void); struct files_struct *dup_fd(struct files_struct *, unsigned, int *) __latent_entropy; void do_close_on_exec(struct files_struct *); int iterate_fd(struct files_struct *, unsigned, -- cgit From 950db38ff2c01b7aabbd7ab4a50b7992750fa63d Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 20 Nov 2020 17:14:20 -0600 Subject: exec: Remove reset_files_struct Now that exec no longer needs to restore the previous value of current->files on error there are no more callers of reset_files_struct so remove it. Acked-by: Christian Brauner v1: https://lkml.kernel.org/r/20200817220425.9389-3-ebiederm@xmission.com Link: https://lkml.kernel.org/r/20201120231441.29911-3-ebiederm@xmission.com Signed-off-by: Eric W. Biederman --- include/linux/fdtable.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index f46a084b60b2..7cc9885044d9 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -108,7 +108,6 @@ struct task_struct; struct files_struct *get_files_struct(struct task_struct *); void put_files_struct(struct files_struct *fs); -void reset_files_struct(struct files_struct *); int unshare_files(void); struct files_struct *dup_fd(struct files_struct *, unsigned, int *) __latent_entropy; void do_close_on_exec(struct files_struct *); -- cgit From bebf684bf330915e6c96313ad7db89a5480fc9c2 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 20 Nov 2020 17:14:24 -0600 Subject: file: Rename __fcheck_files to files_lookup_fd_raw The function fcheck despite it's comment is poorly named as it has no callers that only check it's return value. All of fcheck's callers use the returned file descriptor. The same is true for fcheck_files and __fcheck_files. A new less confusing name is needed. In addition the names of these functions are confusing as they do not report the kind of locks that are needed to be held when these functions are called making error prone to use them. To remedy this I am making the base functio name lookup_fd and will and prefixes and sufficies to indicate the rest of the context. Name the function (previously called __fcheck_files) that proceeds from a struct files_struct, looks up the struct file of a file descriptor, and requires it's callers to verify all of the appropriate locks are held files_lookup_fd_raw. The need for better names became apparent in the last round of discussion of this set of changes[1]. [1] https://lkml.kernel.org/r/CAHk-=wj8BQbgJFLa+J0e=iT-1qpmCRTbPAJ8gd6MJQ=kbRPqyQ@mail.gmail.com Link: https://lkml.kernel.org/r/20201120231441.29911-7-ebiederm@xmission.com Signed-off-by: Eric W. Biederman --- include/linux/fdtable.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index 7cc9885044d9..639933f37da9 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -80,7 +80,7 @@ struct dentry; /* * The caller must ensure that fd table isn't shared or hold rcu or file lock */ -static inline struct file *__fcheck_files(struct files_struct *files, unsigned int fd) +static inline struct file *files_lookup_fd_raw(struct files_struct *files, unsigned int fd) { struct fdtable *fdt = rcu_dereference_raw(files->fdt); @@ -96,7 +96,7 @@ static inline struct file *fcheck_files(struct files_struct *files, unsigned int RCU_LOCKDEP_WARN(!rcu_read_lock_held() && !lockdep_is_held(&files->file_lock), "suspicious rcu_dereference_check() usage"); - return __fcheck_files(files, fd); + return files_lookup_fd_raw(files, fd); } /* -- cgit From 120ce2b0cd52abe73e8b16c23461eb14df5a87d8 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 20 Nov 2020 17:14:25 -0600 Subject: file: Factor files_lookup_fd_locked out of fcheck_files To make it easy to tell where files->file_lock protection is being used when looking up a file create files_lookup_fd_locked. Only allow this function to be called with the file_lock held. Update the callers of fcheck and fcheck_files that are called with the files->file_lock held to call files_lookup_fd_locked instead. Hopefully this makes it easier to quickly understand what is going on. The need for better names became apparent in the last round of discussion of this set of changes[1]. [1] https://lkml.kernel.org/r/CAHk-=wj8BQbgJFLa+J0e=iT-1qpmCRTbPAJ8gd6MJQ=kbRPqyQ@mail.gmail.com Link: https://lkml.kernel.org/r/20201120231441.29911-8-ebiederm@xmission.com Signed-off-by: Eric W. Biederman --- include/linux/fdtable.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/linux') diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index 639933f37da9..fda4b81dd735 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -91,6 +91,13 @@ static inline struct file *files_lookup_fd_raw(struct files_struct *files, unsig return NULL; } +static inline struct file *files_lookup_fd_locked(struct files_struct *files, unsigned int fd) +{ + RCU_LOCKDEP_WARN(!lockdep_is_held(&files->file_lock), + "suspicious rcu_dereference_check() usage"); + return files_lookup_fd_raw(files, fd); +} + static inline struct file *fcheck_files(struct files_struct *files, unsigned int fd) { RCU_LOCKDEP_WARN(!rcu_read_lock_held() && -- cgit From f36c2943274199cb8aef32ac96531ffb7c4b43d0 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 20 Nov 2020 17:14:26 -0600 Subject: file: Replace fcheck_files with files_lookup_fd_rcu This change renames fcheck_files to files_lookup_fd_rcu. All of the remaining callers take the rcu_read_lock before calling this function so the _rcu suffix is appropriate. This change also tightens up the debug check to verify that all callers hold the rcu_read_lock. All callers that used to call files_check with the files->file_lock held have now been changed to call files_lookup_fd_locked. This change of name has helped remind me of which locks and which guarantees are in place helping me to catch bugs later in the patchset. The need for better names became apparent in the last round of discussion of this set of changes[1]. [1] https://lkml.kernel.org/r/CAHk-=wj8BQbgJFLa+J0e=iT-1qpmCRTbPAJ8gd6MJQ=kbRPqyQ@mail.gmail.com Link: https://lkml.kernel.org/r/20201120231441.29911-9-ebiederm@xmission.com Signed-off-by: Eric W. Biederman --- include/linux/fdtable.h | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'include/linux') diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index fda4b81dd735..fa8c402a7790 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -98,10 +98,9 @@ static inline struct file *files_lookup_fd_locked(struct files_struct *files, un return files_lookup_fd_raw(files, fd); } -static inline struct file *fcheck_files(struct files_struct *files, unsigned int fd) +static inline struct file *files_lookup_fd_rcu(struct files_struct *files, unsigned int fd) { - RCU_LOCKDEP_WARN(!rcu_read_lock_held() && - !lockdep_is_held(&files->file_lock), + RCU_LOCKDEP_WARN(!rcu_read_lock_held(), "suspicious rcu_dereference_check() usage"); return files_lookup_fd_raw(files, fd); } @@ -109,7 +108,7 @@ static inline struct file *fcheck_files(struct files_struct *files, unsigned int /* * Check whether the specified fd has an open file. */ -#define fcheck(fd) fcheck_files(current->files, fd) +#define fcheck(fd) files_lookup_fd_rcu(current->files, fd) struct task_struct; -- cgit From 460b4f812a9d473d4b39d87d37844f9fc30a9eb3 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 20 Nov 2020 17:14:27 -0600 Subject: file: Rename fcheck lookup_fd_rcu Also remove the confusing comment about checking if a fd exists. I could not find one instance in the entire kernel that still matches the description or the reason for the name fcheck. The need for better names became apparent in the last round of discussion of this set of changes[1]. [1] https://lkml.kernel.org/r/CAHk-=wj8BQbgJFLa+J0e=iT-1qpmCRTbPAJ8gd6MJQ=kbRPqyQ@mail.gmail.com Link: https://lkml.kernel.org/r/20201120231441.29911-10-ebiederm@xmission.com Signed-off-by: Eric W. Biederman --- include/linux/fdtable.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'include/linux') diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index fa8c402a7790..2a4a8fed536e 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -105,10 +105,10 @@ static inline struct file *files_lookup_fd_rcu(struct files_struct *files, unsig return files_lookup_fd_raw(files, fd); } -/* - * Check whether the specified fd has an open file. - */ -#define fcheck(fd) files_lookup_fd_rcu(current->files, fd) +static inline struct file *lookup_fd_rcu(unsigned int fd) +{ + return files_lookup_fd_rcu(current->files, fd); +} struct task_struct; -- cgit From 3a879fb38082125cc0d8aa89b70c7f3a7cdf584b Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 20 Nov 2020 17:14:28 -0600 Subject: file: Implement task_lookup_fd_rcu As a companion to lookup_fd_rcu implement task_lookup_fd_rcu for querying an arbitrary process about a specific file. Acked-by: Christian Brauner v1: https://lkml.kernel.org/r/20200818103713.aw46m7vprsy4vlve@wittgenstein Link: https://lkml.kernel.org/r/20201120231441.29911-11-ebiederm@xmission.com Signed-off-by: Eric W. Biederman --- include/linux/fdtable.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index 2a4a8fed536e..a0558ae9b40c 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -110,6 +110,8 @@ static inline struct file *lookup_fd_rcu(unsigned int fd) return files_lookup_fd_rcu(current->files, fd); } +struct file *task_lookup_fd_rcu(struct task_struct *task, unsigned int fd); + struct task_struct; struct files_struct *get_files_struct(struct task_struct *); -- cgit From e9a53aeb5e0a838f10fcea74235664e7ad5e6e1a Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 20 Nov 2020 17:14:31 -0600 Subject: file: Implement task_lookup_next_fd_rcu As a companion to fget_task and task_lookup_fd_rcu implement task_lookup_next_fd_rcu that will return the struct file for the first file descriptor number that is equal or greater than the fd argument value, or NULL if there is no such struct file. This allows file descriptors of foreign processes to be iterated through safely, without needed to increment the count on files_struct. Some concern[1] has been expressed that this function takes the task_lock for each iteration and thus for each file descriptor. This place where this function will be called in a commonly used code path is for listing /proc//fd. I did some small benchmarks and did not see any measurable performance differences. For ordinary users ls is likely to stat each of the directory entries and tid_fd_mode called from tid_fd_revalidae has always taken the task lock for each file descriptor. So this does not look like it will be a big change in practice. At some point is will probably be worth changing put_files_struct to free files_struct after an rcu grace period so that task_lock won't be needed at all. [1] https://lkml.kernel.org/r/20200817220425.9389-10-ebiederm@xmission.com v1: https://lkml.kernel.org/r/20200817220425.9389-9-ebiederm@xmission.com Link: https://lkml.kernel.org/r/20201120231441.29911-14-ebiederm@xmission.com Signed-off-by: Eric W. Biederman --- include/linux/fdtable.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index a0558ae9b40c..cf6c52dae3a1 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -111,6 +111,7 @@ static inline struct file *lookup_fd_rcu(unsigned int fd) } struct file *task_lookup_fd_rcu(struct task_struct *task, unsigned int fd); +struct file *task_lookup_next_fd_rcu(struct task_struct *task, unsigned int *fd); struct task_struct; -- cgit From d74ba04d919ebe30bf47406819c18c6b50003d92 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 20 Nov 2020 17:14:35 -0600 Subject: file: Merge __fd_install into fd_install The function __fd_install was added to support binder[1]. With binder fixed[2] there are no more users. As fd_install just calls __fd_install with "files=current->files", merge them together by transforming the files parameter into a local variable initialized to current->files. [1] f869e8a7f753 ("expose a low-level variant of fd_install() for binder") [2] 44d8047f1d87 ("binder: use standard functions to allocate fds") Acked-by: Christian Brauner v1:https://lkml.kernel.org/r/20200817220425.9389-14-ebiederm@xmission.com Link: https://lkml.kernel.org/r/20201120231441.29911-18-ebiederm@xmission.com Signed-off-by: Eric W. Biederman --- include/linux/fdtable.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index cf6c52dae3a1..a5ec736d74a5 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -126,8 +126,6 @@ int iterate_fd(struct files_struct *, unsigned, extern int __alloc_fd(struct files_struct *files, unsigned start, unsigned end, unsigned flags); -extern void __fd_install(struct files_struct *files, - unsigned int fd, struct file *file); extern int __close_fd(struct files_struct *files, unsigned int fd); extern int __close_range(unsigned int fd, unsigned int max_fd, unsigned int flags); -- cgit From aa384d10f3d06d4b85597ff5df41551262220e16 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 20 Nov 2020 17:14:37 -0600 Subject: file: Merge __alloc_fd into alloc_fd The function __alloc_fd was added to support binder[1]. With binder fixed[2] there are no more users. As alloc_fd just calls __alloc_fd with "files=current->files", merge them together by transforming the files parameter into a local variable initialized to current->files. [1] dcfadfa4ec5a ("new helper: __alloc_fd()") [2] 44d8047f1d87 ("binder: use standard functions to allocate fds") Acked-by: Christian Brauner v1: https://lkml.kernel.org/r/20200817220425.9389-16-ebiederm@xmission.com Link: https://lkml.kernel.org/r/20201120231441.29911-20-ebiederm@xmission.com Signed-off-by: Eric W. Biederman --- include/linux/fdtable.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index a5ec736d74a5..dc476ae92f56 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -124,8 +124,6 @@ int iterate_fd(struct files_struct *, unsigned, int (*)(const void *, struct file *, unsigned), const void *); -extern int __alloc_fd(struct files_struct *files, - unsigned start, unsigned end, unsigned flags); extern int __close_fd(struct files_struct *files, unsigned int fd); extern int __close_range(unsigned int fd, unsigned int max_fd, unsigned int flags); -- cgit From 8760c909f54a82aaa6e76da19afe798a0c77c3c3 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 20 Nov 2020 17:14:38 -0600 Subject: file: Rename __close_fd to close_fd and remove the files parameter The function __close_fd was added to support binder[1]. Now that binder has been fixed to no longer need __close_fd[2] all calls to __close_fd pass current->files. Therefore transform the files parameter into a local variable initialized to current->files, and rename __close_fd to close_fd to reflect this change, and keep it in sync with the similar changes to __alloc_fd, and __fd_install. This removes the need for callers to care about the extra care that needs to be take if anything except current->files is passed, by limiting the callers to only operation on current->files. [1] 483ce1d4b8c3 ("take descriptor-related part of close() to file.c") [2] 44d8047f1d87 ("binder: use standard functions to allocate fds") Acked-by: Christian Brauner v1: https://lkml.kernel.org/r/20200817220425.9389-17-ebiederm@xmission.com Link: https://lkml.kernel.org/r/20201120231441.29911-21-ebiederm@xmission.com Signed-off-by: Eric W. Biederman --- include/linux/fdtable.h | 3 +-- include/linux/syscalls.h | 6 +++--- 2 files changed, 4 insertions(+), 5 deletions(-) (limited to 'include/linux') diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index dc476ae92f56..dad4a488ce60 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -124,8 +124,7 @@ int iterate_fd(struct files_struct *, unsigned, int (*)(const void *, struct file *, unsigned), const void *); -extern int __close_fd(struct files_struct *files, - unsigned int fd); +extern int close_fd(unsigned int fd); extern int __close_range(unsigned int fd, unsigned int max_fd, unsigned int flags); extern int __close_fd_get_file(unsigned int fd, struct file **res); extern int unshare_fd(unsigned long unshare_flags, unsigned int max_fds, diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 37bea07c12f2..9e055a0579f8 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -1295,16 +1295,16 @@ static inline long ksys_ftruncate(unsigned int fd, loff_t length) return do_sys_ftruncate(fd, length, 1); } -extern int __close_fd(struct files_struct *files, unsigned int fd); +extern int close_fd(unsigned int fd); /* * In contrast to sys_close(), this stub does not check whether the syscall * should or should not be restarted, but returns the raw error codes from - * __close_fd(). + * close_fd(). */ static inline int ksys_close(unsigned int fd) { - return __close_fd(current->files, fd); + return close_fd(fd); } extern long do_sys_truncate(const char __user *pathname, loff_t length); -- cgit From 1572bfdf21d4d50e51941498ffe0b56c2289f783 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 20 Nov 2020 17:14:39 -0600 Subject: file: Replace ksys_close with close_fd Now that ksys_close is exactly identical to close_fd replace the one caller of ksys_close with close_fd. [1] https://lkml.kernel.org/r/20200818112020.GA17080@infradead.org Suggested-by: Christoph Hellwig Link: https://lkml.kernel.org/r/20201120231441.29911-22-ebiederm@xmission.com Signed-off-by: Eric W. Biederman --- include/linux/syscalls.h | 12 ------------ 1 file changed, 12 deletions(-) (limited to 'include/linux') diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 9e055a0579f8..0f72f380db72 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -1295,18 +1295,6 @@ static inline long ksys_ftruncate(unsigned int fd, loff_t length) return do_sys_ftruncate(fd, length, 1); } -extern int close_fd(unsigned int fd); - -/* - * In contrast to sys_close(), this stub does not check whether the syscall - * should or should not be restarted, but returns the raw error codes from - * close_fd(). - */ -static inline int ksys_close(unsigned int fd) -{ - return close_fd(fd); -} - extern long do_sys_truncate(const char __user *pathname, loff_t length); static inline long ksys_truncate(const char __user *pathname, loff_t length) -- cgit From 9fe83c43e71cdb8e5b9520bcb98706a2b3c680c8 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 20 Nov 2020 17:14:40 -0600 Subject: file: Rename __close_fd_get_file close_fd_get_file The function close_fd_get_file is explicitly a variant of __close_fd[1]. Now that __close_fd has been renamed close_fd, rename close_fd_get_file to be consistent with close_fd. When __alloc_fd, __close_fd and __fd_install were introduced the double underscore indicated that the function took a struct files_struct parameter. The function __close_fd_get_file never has so the naming has always been inconsistent. This just cleans things up so there are not any lingering mentions or references __close_fd left in the code. [1] 80cd795630d6 ("binder: fix use-after-free due to ksys_close() during fdget()") Link: https://lkml.kernel.org/r/20201120231441.29911-23-ebiederm@xmission.com Signed-off-by: Eric W. Biederman --- include/linux/fdtable.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index dad4a488ce60..4ed3589f9294 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -126,7 +126,7 @@ int iterate_fd(struct files_struct *, unsigned, extern int close_fd(unsigned int fd); extern int __close_range(unsigned int fd, unsigned int max_fd, unsigned int flags); -extern int __close_fd_get_file(unsigned int fd, struct file **res); +extern int close_fd_get_file(unsigned int fd, struct file **res); extern int unshare_fd(unsigned long unshare_flags, unsigned int max_fds, struct files_struct **new_fdp); -- cgit From fa67bf885e5211c7dce9514ef2877212c0a5e09e Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 20 Nov 2020 17:14:41 -0600 Subject: file: Remove get_files_struct When discussing[1] exec and posix file locks it was realized that none of the callers of get_files_struct fundamentally needed to call get_files_struct, and that by switching them to helper functions instead it will both simplify their code and remove unnecessary increments of files_struct.count. Those unnecessary increments can result in exec unnecessarily unsharing files_struct which breaking posix locks, and it can result in fget_light having to fallback to fget reducing system performance. Now that get_files_struct has no more users and can not cause the problems for posix file locking and fget_light remove get_files_struct so that it does not gain any new users. [1] https://lkml.kernel.org/r/20180915160423.GA31461@redhat.com Suggested-by: Oleg Nesterov Acked-by: Christian Brauner v1: https://lkml.kernel.org/r/20200817220425.9389-13-ebiederm@xmission.com Link: https://lkml.kernel.org/r/20201120231441.29911-24-ebiederm@xmission.com Signed-off-by: Eric W. Biederman --- include/linux/fdtable.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index 4ed3589f9294..d0e78174874a 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -115,7 +115,6 @@ struct file *task_lookup_next_fd_rcu(struct task_struct *task, unsigned int *fd) struct task_struct; -struct files_struct *get_files_struct(struct task_struct *); void put_files_struct(struct files_struct *fs); int unshare_files(void); struct files_struct *dup_fd(struct files_struct *, unsigned, int *) __latent_entropy; -- cgit