diff options
| -rw-r--r-- | include/linux/compat.h | 18 | ||||
| -rw-r--r-- | include/linux/sched.h | 3 | ||||
| -rw-r--r-- | kernel/Makefile | 3 | ||||
| -rw-r--r-- | kernel/compat.c | 23 | ||||
| -rw-r--r-- | kernel/exit.c | 5 | ||||
| -rw-r--r-- | kernel/futex_compat.c | 142 |
6 files changed, 171 insertions, 23 deletions
diff --git a/include/linux/compat.h b/include/linux/compat.h index 24d659cdbaf..6d3a654be1a 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -147,6 +147,24 @@ typedef struct compat_sigevent { } _sigev_un; } compat_sigevent_t; +struct compat_robust_list { + compat_uptr_t next; +}; + +struct compat_robust_list_head { + struct compat_robust_list list; + compat_long_t futex_offset; + compat_uptr_t list_op_pending; +}; + +extern void compat_exit_robust_list(struct task_struct *curr); + +asmlinkage long +compat_sys_set_robust_list(struct compat_robust_list_head __user *head, + compat_size_t len); +asmlinkage long +compat_sys_get_robust_list(int pid, compat_uptr_t *head_ptr, + compat_size_t __user *len_ptr); long compat_sys_semctl(int first, int second, int third, void __user *uptr); long compat_sys_msgsnd(int first, int second, int third, void __user *uptr); diff --git a/include/linux/sched.h b/include/linux/sched.h index fd4848f2d75..20b4f0372e4 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -874,6 +874,9 @@ struct task_struct { int cpuset_mem_spread_rotor; #endif struct robust_list_head __user *robust_list; +#ifdef CONFIG_COMPAT + struct compat_robust_list_head __user *compat_robust_list; +#endif atomic_t fs_excl; /* holding fs exclusive resources */ struct rcu_head rcu; diff --git a/kernel/Makefile b/kernel/Makefile index ff1c11dc12c..58908f9d156 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -12,6 +12,9 @@ obj-y = sched.o fork.o exec_domain.o panic.o printk.o profile.o \ obj-$(CONFIG_DEBUG_MUTEXES) += mutex-debug.o obj-$(CONFIG_FUTEX) += futex.o +ifeq ($(CONFIG_COMPAT),y) +obj-$(CONFIG_FUTEX) += futex_compat.o +endif obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o obj-$(CONFIG_SMP) += cpu.o spinlock.o obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o diff --git a/kernel/compat.c b/kernel/compat.c index b9bdd1271f4..c1601a84f8d 100644 --- a/kernel/compat.c +++ b/kernel/compat.c @@ -17,7 +17,6 @@ #include <linux/time.h> #include <linux/signal.h> #include <linux/sched.h> /* for MAX_SCHEDULE_TIMEOUT */ -#include <linux/futex.h> /* for FUTEX_WAIT */ #include <linux/syscalls.h> #include <linux/unistd.h> #include <linux/security.h> @@ -239,28 +238,6 @@ asmlinkage long compat_sys_sigprocmask(int how, compat_old_sigset_t __user *set, return ret; } -#ifdef CONFIG_FUTEX -asmlinkage long compat_sys_futex(u32 __user *uaddr, int op, int val, - struct compat_timespec __user *utime, u32 __user *uaddr2, - int val3) -{ - struct timespec t; - unsigned long timeout = MAX_SCHEDULE_TIMEOUT; - int val2 = 0; - - if ((op == FUTEX_WAIT) && utime) { - if (get_compat_timespec(&t, utime)) - return -EFAULT; - timeout = timespec_to_jiffies(&t) + 1; - } - if (op >= FUTEX_REQUEUE) - val2 = (int) (unsigned long) utime; - - return do_futex((unsigned long)uaddr, op, val, timeout, - (unsigned long)uaddr2, val2, val3); -} -#endif - asmlinkage long compat_sys_setrlimit(unsigned int resource, struct compat_rlimit __user *rlim) { diff --git a/kernel/exit.c b/kernel/exit.c index aecb48ca737..a8c7efc7a68 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -32,6 +32,7 @@ #include <linux/cn_proc.h> #include <linux/mutex.h> #include <linux/futex.h> +#include <linux/compat.h> #include <asm/uaccess.h> #include <asm/unistd.h> @@ -855,6 +856,10 @@ fastcall NORET_TYPE void do_exit(long code) } if (unlikely(tsk->robust_list)) exit_robust_list(tsk); +#ifdef CONFIG_COMPAT + if (unlikely(tsk->compat_robust_list)) + compat_exit_robust_list(tsk); +#endif exit_mm(tsk); exit_sem(tsk); diff --git a/kernel/futex_compat.c b/kernel/futex_compat.c new file mode 100644 index 00000000000..c153559ef28 --- /dev/null +++ b/kernel/futex_compat.c @@ -0,0 +1,142 @@ +/* + * linux/kernel/futex_compat.c + * + * Futex compatibililty routines. + * + * Copyright 2006, Red Hat, Inc., Ingo Molnar + */ + +#include <linux/linkage.h> +#include <linux/compat.h> +#include <linux/futex.h> + +#include <asm/uaccess.h> + +/* + * Walk curr->robust_list (very carefully, it's a userspace list!) + * and mark any locks found there dead, and notify any waiters. + * + * We silently return on any sign of list-walking problem. + */ +void compat_exit_robust_list(struct task_struct *curr) +{ + struct compat_robust_list_head __user *head = curr->compat_robust_list; + struct robust_list __user *entry, *pending; + compat_uptr_t uentry, upending; + unsigned int limit = ROBUST_LIST_LIMIT; + compat_long_t futex_offset; + + /* + * Fetch the list head (which was registered earlier, via + * sys_set_robust_list()): + */ + if (get_user(uentry, &head->list.next)) + return; + entry = compat_ptr(uentry); + /* + * Fetch the relative futex offset: + */ + if (get_user(futex_offset, &head->futex_offset)) + return; + /* + * Fetch any possibly pending lock-add first, and handle it + * if it exists: + */ + if (get_user(upending, &head->list_op_pending)) + return; + pending = compat_ptr(upending); + if (upending) + handle_futex_death((void *)pending + futex_offset, curr); + + while (compat_ptr(uentry) != &head->list) { + /* + * A pending lock might already be on the list, so + * dont process it twice: + */ + if (entry != pending) + if (handle_futex_death((void *)entry + futex_offset, + curr)) + return; + + /* + * Fetch the next entry in the list: + */ + if (get_user(uentry, (compat_uptr_t *)&entry->next)) + return; + entry = compat_ptr(uentry); + /* + * Avoid excessively long or circular lists: + */ + if (!--limit) + break; + + cond_resched(); + } +} + +asmlinkage long +compat_sys_set_robust_list(struct compat_robust_list_head __user *head, + compat_size_t len) +{ + if (unlikely(len != sizeof(*head))) + return -EINVAL; + + current->compat_robust_list = head; + + return 0; +} + +asmlinkage long +compat_sys_get_robust_list(int pid, compat_uptr_t *head_ptr, + compat_size_t __user *len_ptr) +{ + struct compat_robust_list_head *head; + unsigned long ret; + + if (!pid) + head = current->compat_robust_list; + else { + struct task_struct *p; + + ret = -ESRCH; + read_lock(&tasklist_lock); + p = find_task_by_pid(pid); + if (!p) + goto err_unlock; + ret = -EPERM; + if ((current->euid != p->euid) && (current->euid != p->uid) && + !capable(CAP_SYS_PTRACE)) + goto err_unlock; + head = p->compat_robust_list; + read_unlock(&tasklist_lock); + } + + if (put_user(sizeof(*head), len_ptr)) + return -EFAULT; + return put_user(ptr_to_compat(head), head_ptr); + +err_unlock: + read_unlock(&tasklist_lock); + + return ret; +} + +asmlinkage long compat_sys_futex(u32 __user *uaddr, int op, int val, + struct compat_timespec __user *utime, u32 __user *uaddr2, + int val3) +{ + struct timespec t; + unsigned long timeout = MAX_SCHEDULE_TIMEOUT; + int val2 = 0; + + if ((op == FUTEX_WAIT) && utime) { + if (get_compat_timespec(&t, utime)) + return -EFAULT; + timeout = timespec_to_jiffies(&t) + 1; + } + if (op >= FUTEX_REQUEUE) + val2 = (int) (unsigned long) utime; + + return do_futex((unsigned long)uaddr, op, val, timeout, + (unsigned long)uaddr2, val2, val3); +} |