diff options
Diffstat (limited to 'kernel/fork.c')
| -rw-r--r-- | kernel/fork.c | 64 |
1 files changed, 25 insertions, 39 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index 99076dbe27d8..cc760491f201 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -44,6 +44,7 @@ #include <linux/fs.h> #include <linux/mm.h> #include <linux/mm_inline.h> +#include <linux/memblock.h> #include <linux/nsproxy.h> #include <linux/capability.h> #include <linux/cpu.h> @@ -115,6 +116,8 @@ #define CREATE_TRACE_POINTS #include <trace/events/task.h> +#include <kunit/visibility.h> + /* * Minimum number of threads to boot the kernel */ @@ -205,9 +208,10 @@ static bool try_release_thread_stack_to_cache(struct vm_struct *vm) unsigned int i; for (i = 0; i < NR_CACHED_STACKS; i++) { - if (this_cpu_cmpxchg(cached_stacks[i], NULL, vm) != NULL) - continue; - return true; + struct vm_struct *tmp = NULL; + + if (this_cpu_try_cmpxchg(cached_stacks[i], &tmp, vm)) + return true; } return false; } @@ -616,12 +620,6 @@ static void dup_mm_exe_file(struct mm_struct *mm, struct mm_struct *oldmm) exe_file = get_mm_exe_file(oldmm); RCU_INIT_POINTER(mm->exe_file, exe_file); - /* - * We depend on the oldmm having properly denied write access to the - * exe_file already. - */ - if (exe_file && deny_write_access(exe_file)) - pr_warn_once("deny_write_access() failed in %s\n", __func__); } #ifdef CONFIG_MMU @@ -996,10 +994,10 @@ void __init __weak arch_task_cache_init(void) { } /* * set_max_threads */ -static void set_max_threads(unsigned int max_threads_suggested) +static void __init set_max_threads(unsigned int max_threads_suggested) { u64 threads; - unsigned long nr_pages = totalram_pages(); + unsigned long nr_pages = PHYS_PFN(memblock_phys_mem_size() - memblock_reserved_size()); /* * The number of threads shall be limited such that the thread @@ -1022,7 +1020,7 @@ static void set_max_threads(unsigned int max_threads_suggested) int arch_task_struct_size __read_mostly; #endif -static void task_struct_whitelist(unsigned long *offset, unsigned long *size) +static void __init task_struct_whitelist(unsigned long *offset, unsigned long *size) { /* Fetch thread_struct whitelist for the architecture. */ arch_thread_struct_whitelist(offset, size); @@ -1334,6 +1332,7 @@ struct mm_struct *mm_alloc(void) memset(mm, 0, sizeof(*mm)); return mm_init(mm, current, current_user_ns()); } +EXPORT_SYMBOL_IF_KUNIT(mm_alloc); static inline void __mmput(struct mm_struct *mm) { @@ -1412,20 +1411,11 @@ int set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file) */ old_exe_file = rcu_dereference_raw(mm->exe_file); - if (new_exe_file) { - /* - * We expect the caller (i.e., sys_execve) to already denied - * write access, so this is unlikely to fail. - */ - if (unlikely(deny_write_access(new_exe_file))) - return -EACCES; + if (new_exe_file) get_file(new_exe_file); - } rcu_assign_pointer(mm->exe_file, new_exe_file); - if (old_exe_file) { - allow_write_access(old_exe_file); + if (old_exe_file) fput(old_exe_file); - } return 0; } @@ -1464,9 +1454,6 @@ int replace_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file) return ret; } - ret = deny_write_access(new_exe_file); - if (ret) - return -EACCES; get_file(new_exe_file); /* set the new file */ @@ -1475,10 +1462,8 @@ int replace_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file) rcu_assign_pointer(mm->exe_file, new_exe_file); mmap_write_unlock(mm); - if (old_exe_file) { - allow_write_access(old_exe_file); + if (old_exe_file) fput(old_exe_file); - } return 0; } @@ -1536,14 +1521,13 @@ struct mm_struct *get_task_mm(struct task_struct *task) { struct mm_struct *mm; + if (task->flags & PF_KTHREAD) + return NULL; + task_lock(task); mm = task->mm; - if (mm) { - if (task->flags & PF_KTHREAD) - mm = NULL; - else - mmget(mm); - } + if (mm) + mmget(mm); task_unlock(task); return mm; } @@ -2941,8 +2925,6 @@ SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp, } #endif -#ifdef __ARCH_WANT_SYS_CLONE3 - noinline static int copy_clone_args_from_user(struct kernel_clone_args *kargs, struct clone_args __user *uargs, size_t usize) @@ -3086,6 +3068,11 @@ SYSCALL_DEFINE2(clone3, struct clone_args __user *, uargs, size_t, size) struct kernel_clone_args kargs; pid_t set_tid[MAX_PID_NS_LEVEL]; +#ifdef __ARCH_BROKEN_SYS_CLONE3 +#warning clone3() entry point is missing, please fix + return -ENOSYS; +#endif + kargs.set_tid = set_tid; err = copy_clone_args_from_user(&kargs, uargs, size); @@ -3097,7 +3084,6 @@ SYSCALL_DEFINE2(clone3, struct clone_args __user *, uargs, size_t, size) return kernel_clone(&kargs); } -#endif void walk_process_tree(struct task_struct *top, proc_visitor visitor, void *data) { @@ -3418,7 +3404,7 @@ int unshare_files(void) return 0; } -int sysctl_max_threads(struct ctl_table *table, int write, +int sysctl_max_threads(const struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos) { struct ctl_table t; |