diff options
Diffstat (limited to 'kernel/signal.c')
-rw-r--r-- | kernel/signal.c | 435 |
1 files changed, 281 insertions, 154 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index 5843c541fda9..dbd2e4db24cf 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -78,6 +78,10 @@ static bool sig_task_ignored(struct task_struct *t, int sig, bool force) handler = sig_handler(t, sig); + /* SIGKILL and SIGSTOP may not be sent to the global init */ + if (unlikely(is_global_init(t) && sig_kernel_only(sig))) + return true; + if (unlikely(t->signal->flags & SIGNAL_UNKILLABLE) && handler == SIG_DFL && !(force && sig_kernel_only(sig))) return true; @@ -172,6 +176,7 @@ void recalc_sigpending(void) clear_thread_flag(TIF_SIGPENDING); } +EXPORT_SYMBOL(recalc_sigpending); void calculate_sigpending(void) { @@ -462,6 +467,7 @@ void flush_signals(struct task_struct *t) flush_sigqueue(&t->signal->shared_pending); spin_unlock_irqrestore(&t->sighand->siglock, flags); } +EXPORT_SYMBOL(flush_signals); #ifdef CONFIG_POSIX_TIMERS static void __flush_itimer_signals(struct sigpending *pending) @@ -543,7 +549,7 @@ bool unhandled_signal(struct task_struct *tsk, int sig) return !tsk->ptrace; } -static void collect_signal(int sig, struct sigpending *list, siginfo_t *info, +static void collect_signal(int sig, struct sigpending *list, kernel_siginfo_t *info, bool *resched_timer) { struct sigqueue *q, *first = NULL; @@ -589,7 +595,7 @@ still_pending: } static int __dequeue_signal(struct sigpending *pending, sigset_t *mask, - siginfo_t *info, bool *resched_timer) + kernel_siginfo_t *info, bool *resched_timer) { int sig = next_signal(pending, mask); @@ -604,7 +610,7 @@ static int __dequeue_signal(struct sigpending *pending, sigset_t *mask, * * All callers have to hold the siglock. */ -int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info) +int dequeue_signal(struct task_struct *tsk, sigset_t *mask, kernel_siginfo_t *info) { bool resched_timer = false; int signr; @@ -680,6 +686,7 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info) #endif return signr; } +EXPORT_SYMBOL_GPL(dequeue_signal); /* * Tell a process that it has a new active signal.. @@ -730,12 +737,12 @@ static void flush_sigqueue_mask(sigset_t *mask, struct sigpending *s) } } -static inline int is_si_special(const struct siginfo *info) +static inline int is_si_special(const struct kernel_siginfo *info) { - return info <= SEND_SIG_FORCED; + return info <= SEND_SIG_PRIV; } -static inline bool si_fromuser(const struct siginfo *info) +static inline bool si_fromuser(const struct kernel_siginfo *info) { return info == SEND_SIG_NOINFO || (!is_si_special(info) && SI_FROMUSER(info)); @@ -760,7 +767,7 @@ static bool kill_ok_by_cred(struct task_struct *t) * Bad permissions for sending the signal * - the caller must hold the RCU read lock */ -static int check_kill_permission(int sig, struct siginfo *info, +static int check_kill_permission(int sig, struct kernel_siginfo *info, struct task_struct *t) { struct pid *sid; @@ -1003,7 +1010,7 @@ static inline bool legacy_queue(struct sigpending *signals, int sig) } #ifdef CONFIG_USER_NS -static inline void userns_fixup_signal_uid(struct siginfo *info, struct task_struct *t) +static inline void userns_fixup_signal_uid(struct kernel_siginfo *info, struct task_struct *t) { if (current_user_ns() == task_cred_xxx(t, user_ns)) return; @@ -1017,13 +1024,13 @@ static inline void userns_fixup_signal_uid(struct siginfo *info, struct task_str rcu_read_unlock(); } #else -static inline void userns_fixup_signal_uid(struct siginfo *info, struct task_struct *t) +static inline void userns_fixup_signal_uid(struct kernel_siginfo *info, struct task_struct *t) { return; } #endif -static int __send_signal(int sig, struct siginfo *info, struct task_struct *t, +static int __send_signal(int sig, struct kernel_siginfo *info, struct task_struct *t, enum pid_type type, int from_ancestor_ns) { struct sigpending *pending; @@ -1035,7 +1042,7 @@ static int __send_signal(int sig, struct siginfo *info, struct task_struct *t, result = TRACE_SIGNAL_IGNORED; if (!prepare_signal(sig, t, - from_ancestor_ns || (info == SEND_SIG_FORCED))) + from_ancestor_ns || (info == SEND_SIG_PRIV))) goto ret; pending = (type != PIDTYPE_PID) ? &t->signal->shared_pending : &t->pending; @@ -1050,10 +1057,10 @@ static int __send_signal(int sig, struct siginfo *info, struct task_struct *t, result = TRACE_SIGNAL_DELIVERED; /* - * fast-pathed signals for kernel-internal things like SIGSTOP - * or SIGKILL. + * Skip useless siginfo allocation for SIGKILL SIGSTOP, + * and kernel threads. */ - if (info == SEND_SIG_FORCED) + if (sig_kernel_only(sig) || (t->flags & PF_KTHREAD)) goto out_set; /* @@ -1143,7 +1150,7 @@ ret: return ret; } -static int send_signal(int sig, struct siginfo *info, struct task_struct *t, +static int send_signal(int sig, struct kernel_siginfo *info, struct task_struct *t, enum pid_type type) { int from_ancestor_ns = 0; @@ -1190,18 +1197,12 @@ static int __init setup_print_fatal_signals(char *str) __setup("print-fatal-signals=", setup_print_fatal_signals); int -__group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p) +__group_send_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *p) { return send_signal(sig, info, p, PIDTYPE_TGID); } -static int -specific_send_sig_info(int sig, struct siginfo *info, struct task_struct *t) -{ - return send_signal(sig, info, t, PIDTYPE_PID); -} - -int do_send_sig_info(int sig, struct siginfo *info, struct task_struct *p, +int do_send_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *p, enum pid_type type) { unsigned long flags; @@ -1227,7 +1228,7 @@ int do_send_sig_info(int sig, struct siginfo *info, struct task_struct *p, * that is why we also clear SIGNAL_UNKILLABLE. */ int -force_sig_info(int sig, struct siginfo *info, struct task_struct *t) +force_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *t) { unsigned long int flags; int ret, blocked, ignored; @@ -1250,7 +1251,7 @@ force_sig_info(int sig, struct siginfo *info, struct task_struct *t) */ if (action->sa.sa_handler == SIG_DFL && !t->ptrace) t->signal->flags &= ~SIGNAL_UNKILLABLE; - ret = specific_send_sig_info(sig, info, t); + ret = send_signal(sig, info, t, PIDTYPE_PID); spin_unlock_irqrestore(&t->sighand->siglock, flags); return ret; @@ -1315,8 +1316,8 @@ struct sighand_struct *__lock_task_sighand(struct task_struct *tsk, /* * send signal info to all the members of a group */ -int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p, - enum pid_type type) +int group_send_sig_info(int sig, struct kernel_siginfo *info, + struct task_struct *p, enum pid_type type) { int ret; @@ -1335,7 +1336,7 @@ int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p, * control characters do (^C, ^Z etc) * - the caller must hold at least a readlock on tasklist_lock */ -int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp) +int __kill_pgrp_info(int sig, struct kernel_siginfo *info, struct pid *pgrp) { struct task_struct *p = NULL; int retval, success; @@ -1350,7 +1351,7 @@ int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp) return success ? 0 : retval; } -int kill_pid_info(int sig, struct siginfo *info, struct pid *pid) +int kill_pid_info(int sig, struct kernel_siginfo *info, struct pid *pid) { int error = -ESRCH; struct task_struct *p; @@ -1372,7 +1373,7 @@ int kill_pid_info(int sig, struct siginfo *info, struct pid *pid) } } -static int kill_proc_info(int sig, struct siginfo *info, pid_t pid) +static int kill_proc_info(int sig, struct kernel_siginfo *info, pid_t pid) { int error; rcu_read_lock(); @@ -1393,7 +1394,7 @@ static inline bool kill_as_cred_perm(const struct cred *cred, } /* like kill_pid_info(), but doesn't use uid/euid of "current" */ -int kill_pid_info_as_cred(int sig, struct siginfo *info, struct pid *pid, +int kill_pid_info_as_cred(int sig, struct kernel_siginfo *info, struct pid *pid, const struct cred *cred) { int ret = -EINVAL; @@ -1437,7 +1438,7 @@ EXPORT_SYMBOL_GPL(kill_pid_info_as_cred); * is probably wrong. Should make it like BSD or SYSV. */ -static int kill_something_info(int sig, struct siginfo *info, pid_t pid) +static int kill_something_info(int sig, struct kernel_siginfo *info, pid_t pid) { int ret; @@ -1481,7 +1482,7 @@ static int kill_something_info(int sig, struct siginfo *info, pid_t pid) * These are for backward compatibility with the rest of the kernel source. */ -int send_sig_info(int sig, struct siginfo *info, struct task_struct *p) +int send_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *p) { /* * Make sure legacy kernel users don't send in bad values @@ -1492,6 +1493,7 @@ int send_sig_info(int sig, struct siginfo *info, struct task_struct *p) return do_send_sig_info(sig, info, p, PIDTYPE_PID); } +EXPORT_SYMBOL(send_sig_info); #define __si_special(priv) \ ((priv) ? SEND_SIG_PRIV : SEND_SIG_NOINFO) @@ -1501,11 +1503,13 @@ send_sig(int sig, struct task_struct *p, int priv) { return send_sig_info(sig, __si_special(priv), p); } +EXPORT_SYMBOL(send_sig); void force_sig(int sig, struct task_struct *p) { force_sig_info(sig, SEND_SIG_PRIV, p); } +EXPORT_SYMBOL(force_sig); /* * When things go south during signal handling, we @@ -1529,7 +1533,7 @@ int force_sig_fault(int sig, int code, void __user *addr ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr) , struct task_struct *t) { - struct siginfo info; + struct kernel_siginfo info; clear_siginfo(&info); info.si_signo = sig; @@ -1552,7 +1556,7 @@ int send_sig_fault(int sig, int code, void __user *addr ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr) , struct task_struct *t) { - struct siginfo info; + struct kernel_siginfo info; clear_siginfo(&info); info.si_signo = sig; @@ -1572,7 +1576,7 @@ int send_sig_fault(int sig, int code, void __user *addr int force_sig_mceerr(int code, void __user *addr, short lsb, struct task_struct *t) { - struct siginfo info; + struct kernel_siginfo info; WARN_ON((code != BUS_MCEERR_AO) && (code != BUS_MCEERR_AR)); clear_siginfo(&info); @@ -1586,7 +1590,7 @@ int force_sig_mceerr(int code, void __user *addr, short lsb, struct task_struct int send_sig_mceerr(int code, void __user *addr, short lsb, struct task_struct *t) { - struct siginfo info; + struct kernel_siginfo info; WARN_ON((code != BUS_MCEERR_AO) && (code != BUS_MCEERR_AR)); clear_siginfo(&info); @@ -1601,7 +1605,7 @@ EXPORT_SYMBOL(send_sig_mceerr); int force_sig_bnderr(void __user *addr, void __user *lower, void __user *upper) { - struct siginfo info; + struct kernel_siginfo info; clear_siginfo(&info); info.si_signo = SIGSEGV; @@ -1616,7 +1620,7 @@ int force_sig_bnderr(void __user *addr, void __user *lower, void __user *upper) #ifdef SEGV_PKUERR int force_sig_pkuerr(void __user *addr, u32 pkey) { - struct siginfo info; + struct kernel_siginfo info; clear_siginfo(&info); info.si_signo = SIGSEGV; @@ -1633,7 +1637,7 @@ int force_sig_pkuerr(void __user *addr, u32 pkey) */ int force_sig_ptrace_errno_trap(int errno, void __user *addr) { - struct siginfo info; + struct kernel_siginfo info; clear_siginfo(&info); info.si_signo = SIGTRAP; @@ -1762,7 +1766,7 @@ ret: */ bool do_notify_parent(struct task_struct *tsk, int sig) { - struct siginfo info; + struct kernel_siginfo info; unsigned long flags; struct sighand_struct *psig; bool autoreap = false; @@ -1867,7 +1871,7 @@ bool do_notify_parent(struct task_struct *tsk, int sig) static void do_notify_parent_cldstop(struct task_struct *tsk, bool for_ptracer, int why) { - struct siginfo info; + struct kernel_siginfo info; unsigned long flags; struct task_struct *parent; struct sighand_struct *sighand; @@ -1967,7 +1971,7 @@ static bool sigkill_pending(struct task_struct *tsk) * If we actually decide not to stop at all because the tracer * is gone, we keep current->exit_code unless clear_code. */ -static void ptrace_stop(int exit_code, int why, int clear_code, siginfo_t *info) +static void ptrace_stop(int exit_code, int why, int clear_code, kernel_siginfo_t *info) __releases(¤t->sighand->siglock) __acquires(¤t->sighand->siglock) { @@ -2104,7 +2108,7 @@ static void ptrace_stop(int exit_code, int why, int clear_code, siginfo_t *info) static void ptrace_do_notify(int signr, int exit_code, int why) { - siginfo_t info; + kernel_siginfo_t info; clear_siginfo(&info); info.si_signo = signr; @@ -2285,7 +2289,7 @@ static void do_jobctl_trap(void) } } -static int ptrace_signal(int signr, siginfo_t *info) +static int ptrace_signal(int signr, kernel_siginfo_t *info) { /* * We do not check sig_kernel_stop(signr) but set this marker @@ -2326,7 +2330,7 @@ static int ptrace_signal(int signr, siginfo_t *info) /* If the (new) signal is now blocked, requeue it. */ if (sigismember(¤t->blocked, signr)) { - specific_send_sig_info(signr, info, current); + send_signal(signr, info, current, PIDTYPE_PID); signr = 0; } @@ -2636,14 +2640,6 @@ out: } } -EXPORT_SYMBOL(recalc_sigpending); -EXPORT_SYMBOL_GPL(dequeue_signal); -EXPORT_SYMBOL(flush_signals); -EXPORT_SYMBOL(force_sig); -EXPORT_SYMBOL(send_sig); -EXPORT_SYMBOL(send_sig_info); -EXPORT_SYMBOL(sigprocmask); - /* * System call entry points. */ @@ -2737,6 +2733,7 @@ int sigprocmask(int how, sigset_t *set, sigset_t *oldset) __set_current_blocked(&newset); return 0; } +EXPORT_SYMBOL(sigprocmask); /** * sys_rt_sigprocmask - change the list of currently blocked signals @@ -2847,27 +2844,48 @@ COMPAT_SYSCALL_DEFINE2(rt_sigpending, compat_sigset_t __user *, uset, } #endif -enum siginfo_layout siginfo_layout(int sig, int si_code) +static const struct { + unsigned char limit, layout; +} sig_sicodes[] = { + [SIGILL] = { NSIGILL, SIL_FAULT }, + [SIGFPE] = { NSIGFPE, SIL_FAULT }, + [SIGSEGV] = { NSIGSEGV, SIL_FAULT }, + [SIGBUS] = { NSIGBUS, SIL_FAULT }, + [SIGTRAP] = { NSIGTRAP, SIL_FAULT }, +#if defined(SIGEMT) + [SIGEMT] = { NSIGEMT, SIL_FAULT }, +#endif + [SIGCHLD] = { NSIGCHLD, SIL_CHLD }, + [SIGPOLL] = { NSIGPOLL, SIL_POLL }, + [SIGSYS] = { NSIGSYS, SIL_SYS }, +}; + +static bool known_siginfo_layout(unsigned sig, int si_code) +{ + if (si_code == SI_KERNEL) + return true; + else if ((si_code > SI_USER)) { + if (sig_specific_sicodes(sig)) { + if (si_code <= sig_sicodes[sig].limit) + return true; + } + else if (si_code <= NSIGPOLL) + return true; + } + else if (si_code >= SI_DETHREAD) + return true; + else if (si_code == SI_ASYNCNL) + return true; + return false; +} + +enum siginfo_layout siginfo_layout(unsigned sig, int si_code) { enum siginfo_layout layout = SIL_KILL; if ((si_code > SI_USER) && (si_code < SI_KERNEL)) { - static const struct { - unsigned char limit, layout; - } filter[] = { - [SIGILL] = { NSIGILL, SIL_FAULT }, - [SIGFPE] = { NSIGFPE, SIL_FAULT }, - [SIGSEGV] = { NSIGSEGV, SIL_FAULT }, - [SIGBUS] = { NSIGBUS, SIL_FAULT }, - [SIGTRAP] = { NSIGTRAP, SIL_FAULT }, -#if defined(SIGEMT) && defined(NSIGEMT) - [SIGEMT] = { NSIGEMT, SIL_FAULT }, -#endif - [SIGCHLD] = { NSIGCHLD, SIL_CHLD }, - [SIGPOLL] = { NSIGPOLL, SIL_POLL }, - [SIGSYS] = { NSIGSYS, SIL_SYS }, - }; - if ((sig < ARRAY_SIZE(filter)) && (si_code <= filter[sig].limit)) { - layout = filter[sig].layout; + if ((sig < ARRAY_SIZE(sig_sicodes)) && + (si_code <= sig_sicodes[sig].limit)) { + layout = sig_sicodes[sig].layout; /* Handle the exceptions */ if ((sig == SIGBUS) && (si_code >= BUS_MCEERR_AR) && (si_code <= BUS_MCEERR_AO)) @@ -2892,22 +2910,69 @@ enum siginfo_layout siginfo_layout(int sig, int si_code) return layout; } -int copy_siginfo_to_user(siginfo_t __user *to, const siginfo_t *from) +static inline char __user *si_expansion(const siginfo_t __user *info) +{ + return ((char __user *)info) + sizeof(struct kernel_siginfo); +} + +int copy_siginfo_to_user(siginfo_t __user *to, const kernel_siginfo_t *from) { - if (copy_to_user(to, from , sizeof(struct siginfo))) + char __user *expansion = si_expansion(to); + if (copy_to_user(to, from , sizeof(struct kernel_siginfo))) + return -EFAULT; + if (clear_user(expansion, SI_EXPANSION_SIZE)) return -EFAULT; return 0; } +static int post_copy_siginfo_from_user(kernel_siginfo_t *info, + const siginfo_t __user *from) +{ + if (unlikely(!known_siginfo_layout(info->si_signo, info->si_code))) { + char __user *expansion = si_expansion(from); + char buf[SI_EXPANSION_SIZE]; + int i; + /* + * An unknown si_code might need more than + * sizeof(struct kernel_siginfo) bytes. Verify all of the + * extra bytes are 0. This guarantees copy_siginfo_to_user + * will return this data to userspace exactly. + */ + if (copy_from_user(&buf, expansion, SI_EXPANSION_SIZE)) + return -EFAULT; + for (i = 0; i < SI_EXPANSION_SIZE; i++) { + if (buf[i] != 0) + return -E2BIG; + } + } + return 0; +} + +static int __copy_siginfo_from_user(int signo, kernel_siginfo_t *to, + const siginfo_t __user *from) +{ + if (copy_from_user(to, from, sizeof(struct kernel_siginfo))) + return -EFAULT; + to->si_signo = signo; + return post_copy_siginfo_from_user(to, from); +} + +int copy_siginfo_from_user(kernel_siginfo_t *to, const siginfo_t __user *from) +{ + if (copy_from_user(to, from, sizeof(struct kernel_siginfo))) + return -EFAULT; + return post_copy_siginfo_from_user(to, from); +} + #ifdef CONFIG_COMPAT int copy_siginfo_to_user32(struct compat_siginfo __user *to, - const struct siginfo *from) + const struct kernel_siginfo *from) #if defined(CONFIG_X86_X32_ABI) || defined(CONFIG_IA32_EMULATION) { return __copy_siginfo_to_user32(to, from, in_x32_syscall()); } int __copy_siginfo_to_user32(struct compat_siginfo __user *to, - const struct siginfo *from, bool x32_ABI) + const struct kernel_siginfo *from, bool x32_ABI) #endif { struct compat_siginfo new; @@ -2991,88 +3056,106 @@ int __copy_siginfo_to_user32(struct compat_siginfo __user *to, return 0; } -int copy_siginfo_from_user32(struct siginfo *to, - const struct compat_siginfo __user *ufrom) +static int post_copy_siginfo_from_user32(kernel_siginfo_t *to, + const struct compat_siginfo *from) { - struct compat_siginfo from; - - if (copy_from_user(&from, ufrom, sizeof(struct compat_siginfo))) - return -EFAULT; - clear_siginfo(to); - to->si_signo = from.si_signo; - to->si_errno = from.si_errno; - to->si_code = from.si_code; - switch(siginfo_layout(from.si_signo, from.si_code)) { + to->si_signo = from->si_signo; + to->si_errno = from->si_errno; + to->si_code = from->si_code; + switch(siginfo_layout(from->si_signo, from->si_code)) { case SIL_KILL: - to->si_pid = from.si_pid; - to->si_uid = from.si_uid; + to->si_pid = from->si_pid; + to->si_uid = from->si_uid; break; case SIL_TIMER: - to->si_tid = from.si_tid; - to->si_overrun = from.si_overrun; - to->si_int = from.si_int; + to->si_tid = from->si_tid; + to->si_overrun = from->si_overrun; + to->si_int = from->si_int; break; case SIL_POLL: - to->si_band = from.si_band; - to->si_fd = from.si_fd; + to->si_band = from->si_band; + to->si_fd = from->si_fd; break; case SIL_FAULT: - to->si_addr = compat_ptr(from.si_addr); + to->si_addr = compat_ptr(from->si_addr); #ifdef __ARCH_SI_TRAPNO - to->si_trapno = from.si_trapno; + to->si_trapno = from->si_trapno; #endif break; case SIL_FAULT_MCEERR: - to->si_addr = compat_ptr(from.si_addr); + to->si_addr = compat_ptr(from->si_addr); #ifdef __ARCH_SI_TRAPNO - to->si_trapno = from.si_trapno; + to->si_trapno = from->si_trapno; #endif - to->si_addr_lsb = from.si_addr_lsb; + to->si_addr_lsb = from->si_addr_lsb; break; case SIL_FAULT_BNDERR: - to->si_addr = compat_ptr(from.si_addr); + to->si_addr = compat_ptr(from->si_addr); #ifdef __ARCH_SI_TRAPNO - to->si_trapno = from.si_trapno; + to->si_trapno = from->si_trapno; #endif - to->si_lower = compat_ptr(from.si_lower); - to->si_upper = compat_ptr(from.si_upper); + to->si_lower = compat_ptr(from->si_lower); + to->si_upper = compat_ptr(from->si_upper); break; case SIL_FAULT_PKUERR: - to->si_addr = compat_ptr(from.si_addr); + to->si_addr = compat_ptr(from->si_addr); #ifdef __ARCH_SI_TRAPNO - to->si_trapno = from.si_trapno; + to->si_trapno = from->si_trapno; #endif - to->si_pkey = from.si_pkey; + to->si_pkey = from->si_pkey; break; case SIL_CHLD: - to->si_pid = from.si_pid; - to->si_uid = from.si_uid; - to->si_status = from.si_status; + to->si_pid = from->si_pid; + to->si_uid = from->si_uid; + to->si_status = from->si_status; #ifdef CONFIG_X86_X32_ABI if (in_x32_syscall()) { - to->si_utime = from._sifields._sigchld_x32._utime; - to->si_stime = from._sifields._sigchld_x32._stime; + to->si_utime = from->_sifields._sigchld_x32._utime; + to->si_stime = from->_sifields._sigchld_x32._stime; } else #endif { - to->si_utime = from.si_utime; - to->si_stime = from.si_stime; + to->si_utime = from->si_utime; + to->si_stime = from->si_stime; } break; case SIL_RT: - to->si_pid = from.si_pid; - to->si_uid = from.si_uid; - to->si_int = from.si_int; + to->si_pid = from->si_pid; + to->si_uid = from->si_uid; + to->si_int = from->si_int; break; case SIL_SYS: - to->si_call_addr = compat_ptr(from.si_call_addr); - to->si_syscall = from.si_syscall; - to->si_arch = from.si_arch; + to->si_call_addr = compat_ptr(from->si_call_addr); + to->si_syscall = from->si_syscall; + to->si_arch = from->si_arch; break; } return 0; } + +static int __copy_siginfo_from_user32(int signo, struct kernel_siginfo *to, + const struct compat_siginfo __user *ufrom) +{ + struct compat_siginfo from; + + if (copy_from_user(&from, ufrom, sizeof(struct compat_siginfo))) + return -EFAULT; + + from.si_signo = signo; + return post_copy_siginfo_from_user32(to, &from); +} + +int copy_siginfo_from_user32(struct kernel_siginfo *to, + const struct compat_siginfo __user *ufrom) +{ + struct compat_siginfo from; + + if (copy_from_user(&from, ufrom, sizeof(struct compat_siginfo))) + return -EFAULT; + + return post_copy_siginfo_from_user32(to, &from); +} #endif /* CONFIG_COMPAT */ /** @@ -3081,7 +3164,7 @@ int copy_siginfo_from_user32(struct siginfo *to, * @info: if non-null, the signal's siginfo is returned here * @ts: upper bound on process time suspension */ -static int do_sigtimedwait(const sigset_t *which, siginfo_t *info, +static int do_sigtimedwait(const sigset_t *which, kernel_siginfo_t *info, const struct timespec *ts) { ktime_t *to = NULL, timeout = KTIME_MAX; @@ -3145,7 +3228,7 @@ SYSCALL_DEFINE4(rt_sigtimedwait, const sigset_t __user *, uthese, { sigset_t these; struct timespec ts; - siginfo_t info; + kernel_siginfo_t info; int ret; /* XXX: Don't preclude handling different sized sigset_t's. */ @@ -3177,7 +3260,7 @@ COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait, compat_sigset_t __user *, uthese, { sigset_t s; struct timespec t; - siginfo_t info; + kernel_siginfo_t info; long ret; if (sigsetsize != sizeof(sigset_t)) @@ -3209,7 +3292,7 @@ COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait, compat_sigset_t __user *, uthese, */ SYSCALL_DEFINE2(kill, pid_t, pid, int, sig) { - struct siginfo info; + struct kernel_siginfo info; clear_siginfo(&info); info.si_signo = sig; @@ -3222,7 +3305,7 @@ SYSCALL_DEFINE2(kill, pid_t, pid, int, sig) } static int -do_send_specific(pid_t tgid, pid_t pid, int sig, struct siginfo *info) +do_send_specific(pid_t tgid, pid_t pid, int sig, struct kernel_siginfo *info) { struct task_struct *p; int error = -ESRCH; @@ -3253,7 +3336,7 @@ do_send_specific(pid_t tgid, pid_t pid, int sig, struct siginfo *info) static int do_tkill(pid_t tgid, pid_t pid, int sig) { - struct siginfo info; + struct kernel_siginfo info; clear_siginfo(&info); info.si_signo = sig; @@ -3300,7 +3383,7 @@ SYSCALL_DEFINE2(tkill, pid_t, pid, int, sig) return do_tkill(0, pid, sig); } -static int do_rt_sigqueueinfo(pid_t pid, int sig, siginfo_t *info) +static int do_rt_sigqueueinfo(pid_t pid, int sig, kernel_siginfo_t *info) { /* Not even root can pretend to send signals from the kernel. * Nor can they impersonate a kill()/tgkill(), which adds source info. @@ -3309,8 +3392,6 @@ static int do_rt_sigqueueinfo(pid_t pid, int sig, siginfo_t *info) (task_pid_vnr(current) != pid)) return -EPERM; - info->si_signo = sig; - /* POSIX.1b doesn't mention process groups. */ return kill_proc_info(sig, info, pid); } @@ -3324,9 +3405,10 @@ static int do_rt_sigqueueinfo(pid_t pid, int sig, siginfo_t *info) SYSCALL_DEFINE3(rt_sigqueueinfo, pid_t, pid, int, sig, siginfo_t __user *, uinfo) { - siginfo_t info; - if (copy_from_user(&info, uinfo, sizeof(siginfo_t))) - return -EFAULT; + kernel_siginfo_t info; + int ret = __copy_siginfo_from_user(sig, &info, uinfo); + if (unlikely(ret)) + return ret; return do_rt_sigqueueinfo(pid, sig, &info); } @@ -3336,15 +3418,15 @@ COMPAT_SYSCALL_DEFINE3(rt_sigqueueinfo, int, sig, struct compat_siginfo __user *, uinfo) { - siginfo_t info; - int ret = copy_siginfo_from_user32(&info, uinfo); + kernel_siginfo_t info; + int ret = __copy_siginfo_from_user32(sig, &info, uinfo); if (unlikely(ret)) return ret; return do_rt_sigqueueinfo(pid, sig, &info); } #endif -static int do_rt_tgsigqueueinfo(pid_t tgid, pid_t pid, int sig, siginfo_t *info) +static int do_rt_tgsigqueueinfo(pid_t tgid, pid_t pid, int sig, kernel_siginfo_t *info) { /* This is only valid for single tasks */ if (pid <= 0 || tgid <= 0) @@ -3357,19 +3439,16 @@ static int do_rt_tgsigqueueinfo(pid_t tgid, pid_t pid, int sig, siginfo_t *info) (task_pid_vnr(current) != pid)) return -EPERM; - info->si_signo = sig; - return do_send_specific(tgid, pid, sig, info); } SYSCALL_DEFINE4(rt_tgsigqueueinfo, pid_t, tgid, pid_t, pid, int, sig, siginfo_t __user *, uinfo) { - siginfo_t info; - - if (copy_from_user(&info, uinfo, sizeof(siginfo_t))) - return -EFAULT; - + kernel_siginfo_t info; + int ret = __copy_siginfo_from_user(sig, &info, uinfo); + if (unlikely(ret)) + return ret; return do_rt_tgsigqueueinfo(tgid, pid, sig, &info); } @@ -3380,10 +3459,10 @@ COMPAT_SYSCALL_DEFINE4(rt_tgsigqueueinfo, int, sig, struct compat_siginfo __user *, uinfo) { - siginfo_t info; - - if (copy_siginfo_from_user32(&info, uinfo)) - return -EFAULT; + kernel_siginfo_t info; + int ret = __copy_siginfo_from_user32(sig, &info, uinfo); + if (unlikely(ret)) + return ret; return do_rt_tgsigqueueinfo(tgid, pid, sig, &info); } #endif @@ -3460,7 +3539,8 @@ int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact) } static int -do_sigaltstack (const stack_t *ss, stack_t *oss, unsigned long sp) +do_sigaltstack (const stack_t *ss, stack_t *oss, unsigned long sp, + size_t min_ss_size) { struct task_struct *t = current; @@ -3490,7 +3570,7 @@ do_sigaltstack (const stack_t *ss, stack_t *oss, unsigned long sp) ss_size = 0; ss_sp = NULL; } else { - if (unlikely(ss_size < MINSIGSTKSZ)) + if (unlikely(ss_size < min_ss_size)) return -ENOMEM; } @@ -3508,7 +3588,8 @@ SYSCALL_DEFINE2(sigaltstack,const stack_t __user *,uss, stack_t __user *,uoss) if (uss && copy_from_user(&new, uss, sizeof(stack_t))) return -EFAULT; err = do_sigaltstack(uss ? &new : NULL, uoss ? &old : NULL, - current_user_stack_pointer()); + current_user_stack_pointer(), + MINSIGSTKSZ); if (!err && uoss && copy_to_user(uoss, &old, sizeof(stack_t))) err = -EFAULT; return err; @@ -3519,7 +3600,8 @@ int restore_altstack(const stack_t __user *uss) stack_t new; if (copy_from_user(&new, uss, sizeof(stack_t))) return -EFAULT; - (void)do_sigaltstack(&new, NULL, current_user_stack_pointer()); + (void)do_sigaltstack(&new, NULL, current_user_stack_pointer(), + MINSIGSTKSZ); /* squash all but EFAULT for now */ return 0; } @@ -3553,7 +3635,8 @@ static int do_compat_sigaltstack(const compat_stack_t __user *uss_ptr, uss.ss_size = uss32.ss_size; } ret = do_sigaltstack(uss_ptr ? &uss : NULL, &uoss, - compat_user_stack_pointer()); + compat_user_stack_pointer(), + COMPAT_MINSIGSTKSZ); if (ret >= 0 && uoss_ptr) { compat_stack_t old; memset(&old, 0, sizeof(old)); @@ -3962,13 +4045,57 @@ __weak const char *arch_vma_name(struct vm_area_struct *vma) return NULL; } -void __init signals_init(void) +static inline void siginfo_buildtime_checks(void) { - /* If this check fails, the __ARCH_SI_PREAMBLE_SIZE value is wrong! */ - BUILD_BUG_ON(__ARCH_SI_PREAMBLE_SIZE - != offsetof(struct siginfo, _sifields._pad)); BUILD_BUG_ON(sizeof(struct siginfo) != SI_MAX_SIZE); + /* Verify the offsets in the two siginfos match */ +#define CHECK_OFFSET(field) \ + BUILD_BUG_ON(offsetof(siginfo_t, field) != offsetof(kernel_siginfo_t, field)) + + /* kill */ + CHECK_OFFSET(si_pid); + CHECK_OFFSET(si_uid); + + /* timer */ + CHECK_OFFSET(si_tid); + CHECK_OFFSET(si_overrun); + CHECK_OFFSET(si_value); + + /* rt */ + CHECK_OFFSET(si_pid); + CHECK_OFFSET(si_uid); + CHECK_OFFSET(si_value); + + /* sigchld */ + CHECK_OFFSET(si_pid); + CHECK_OFFSET(si_uid); + CHECK_OFFSET(si_status); + CHECK_OFFSET(si_utime); + CHECK_OFFSET(si_stime); + + /* sigfault */ + CHECK_OFFSET(si_addr); + CHECK_OFFSET(si_addr_lsb); + CHECK_OFFSET(si_lower); + CHECK_OFFSET(si_upper); + CHECK_OFFSET(si_pkey); + + /* sigpoll */ + CHECK_OFFSET(si_band); + CHECK_OFFSET(si_fd); + + /* sigsys */ + CHECK_OFFSET(si_call_addr); + CHECK_OFFSET(si_syscall); + CHECK_OFFSET(si_arch); +#undef CHECK_OFFSET +} + +void __init signals_init(void) +{ + siginfo_buildtime_checks(); + sigqueue_cachep = KMEM_CACHE(sigqueue, SLAB_PANIC); } |