Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/kernel/signal.c b/kernel/signal.c
index edc28af..bcd46f5 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/kernel/signal.c
*
@@ -19,7 +20,9 @@
#include <linux/sched/task.h>
#include <linux/sched/task_stack.h>
#include <linux/sched/cputime.h>
+#include <linux/file.h>
#include <linux/fs.h>
+#include <linux/proc_fs.h>
#include <linux/tty.h>
#include <linux/binfmts.h>
#include <linux/coredump.h>
@@ -41,6 +44,8 @@
#include <linux/compiler.h>
#include <linux/posix-timers.h>
#include <linux/livepatch.h>
+#include <linux/cgroup.h>
+#include <linux/audit.h>
#define CREATE_TRACE_POINTS
#include <trace/events/signal.h>
@@ -50,7 +55,6 @@
#include <asm/unistd.h>
#include <asm/siginfo.h>
#include <asm/cacheflush.h>
-#include "audit.h" /* audit_signal_info() */
/*
* SLAB caches for signal bits.
@@ -78,10 +82,19 @@
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;
+ /* Only allow kernel generated signals to this kthread */
+ if (unlikely((t->flags & PF_KTHREAD) &&
+ (handler == SIG_KTHREAD_KERNEL) && !force))
+ return true;
+
return sig_handler_ignored(handler, sig);
}
@@ -140,9 +153,10 @@
static bool recalc_sigpending_tsk(struct task_struct *t)
{
- if ((t->jobctl & JOBCTL_PENDING_MASK) ||
+ if ((t->jobctl & (JOBCTL_PENDING_MASK | JOBCTL_TRAP_FREEZE)) ||
PENDING(&t->pending, &t->blocked) ||
- PENDING(&t->signal->shared_pending, &t->blocked)) {
+ PENDING(&t->signal->shared_pending, &t->blocked) ||
+ cgroup_task_frozen(t)) {
set_tsk_thread_flag(t, TIF_SIGPENDING);
return true;
}
@@ -172,6 +186,7 @@
clear_thread_flag(TIF_SIGPENDING);
}
+EXPORT_SYMBOL(recalc_sigpending);
void calculate_sigpending(void)
{
@@ -339,7 +354,7 @@
* @task has %JOBCTL_STOP_PENDING set and is participating in a group stop.
* Group stop states are cleared and the group stop count is consumed if
* %JOBCTL_STOP_CONSUME was set. If the consumption completes the group
- * stop, the appropriate %SIGNAL_* flags are set.
+ * stop, the appropriate `SIGNAL_*` flags are set.
*
* CONTEXT:
* Must be called with @task->sighand->siglock held.
@@ -462,6 +477,7 @@
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 +559,7 @@
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 +605,7 @@
}
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 +620,7 @@
*
* 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 +696,49 @@
#endif
return signr;
}
+EXPORT_SYMBOL_GPL(dequeue_signal);
+
+static int dequeue_synchronous_signal(kernel_siginfo_t *info)
+{
+ struct task_struct *tsk = current;
+ struct sigpending *pending = &tsk->pending;
+ struct sigqueue *q, *sync = NULL;
+
+ /*
+ * Might a synchronous signal be in the queue?
+ */
+ if (!((pending->signal.sig[0] & ~tsk->blocked.sig[0]) & SYNCHRONOUS_MASK))
+ return 0;
+
+ /*
+ * Return the first synchronous signal in the queue.
+ */
+ list_for_each_entry(q, &pending->list, list) {
+ /* Synchronous signals have a postive si_code */
+ if ((q->info.si_code > SI_USER) &&
+ (sigmask(q->info.si_signo) & SYNCHRONOUS_MASK)) {
+ sync = q;
+ goto next;
+ }
+ }
+ return 0;
+next:
+ /*
+ * Check if there is another siginfo for the same signal.
+ */
+ list_for_each_entry_continue(q, &pending->list, list) {
+ if (q->info.si_signo == sync->info.si_signo)
+ goto still_pending;
+ }
+
+ sigdelset(&pending->signal, sync->info.si_signo);
+ recalc_sigpending();
+still_pending:
+ list_del_init(&sync->list);
+ copy_siginfo(info, &sync->info);
+ __sigqueue_free(sync);
+ return info->si_signo;
+}
/*
* Tell a process that it has a new active signal..
@@ -730,12 +789,12 @@
}
}
-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 +819,7 @@
* 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;
@@ -787,6 +846,7 @@
*/
if (!sid || sid == task_session(current))
break;
+ /* fall through */
default:
return -EPERM;
}
@@ -885,7 +945,7 @@
/*
* The first thread which returns from do_signal_stop()
* will take ->siglock, notice SIGNAL_CLD_MASK, and
- * notify its parent. See get_signal_to_deliver().
+ * notify its parent. See get_signal().
*/
signal_set_stop_flags(signal, why | SIGNAL_STOP_CONTINUED);
signal->group_stop_count = 0;
@@ -1002,29 +1062,8 @@
return (sig < SIGRTMIN) && sigismember(&signals->signal, sig);
}
-#ifdef CONFIG_USER_NS
-static inline void userns_fixup_signal_uid(struct siginfo *info, struct task_struct *t)
-{
- if (current_user_ns() == task_cred_xxx(t, user_ns))
- return;
-
- if (SI_FROMKERNEL(info))
- return;
-
- rcu_read_lock();
- info->si_uid = from_kuid_munged(task_cred_xxx(t, user_ns),
- make_kuid(current_user_ns(), info->si_uid));
- rcu_read_unlock();
-}
-#else
-static inline void userns_fixup_signal_uid(struct siginfo *info, struct task_struct *t)
-{
- return;
-}
-#endif
-
-static int __send_signal(int sig, struct siginfo *info, struct task_struct *t,
- enum pid_type type, int from_ancestor_ns)
+static int __send_signal(int sig, struct kernel_siginfo *info, struct task_struct *t,
+ enum pid_type type, bool force)
{
struct sigpending *pending;
struct sigqueue *q;
@@ -1034,8 +1073,7 @@
assert_spin_locked(&t->sighand->siglock);
result = TRACE_SIGNAL_IGNORED;
- if (!prepare_signal(sig, t,
- from_ancestor_ns || (info == SEND_SIG_PRIV) || (info == SEND_SIG_FORCED)))
+ if (!prepare_signal(sig, t, force))
goto ret;
pending = (type != PIDTYPE_PID) ? &t->signal->shared_pending : &t->pending;
@@ -1050,10 +1088,9 @@
result = TRACE_SIGNAL_DELIVERED;
/*
- * fast-pathed signals for kernel-internal things like SIGSTOP
- * or SIGKILL.
+ * Skip useless siginfo allocation for SIGKILL and kernel threads.
*/
- if (info == SEND_SIG_FORCED)
+ if ((sig == SIGKILL) || (t->flags & PF_KTHREAD))
goto out_set;
/*
@@ -1081,7 +1118,11 @@
q->info.si_code = SI_USER;
q->info.si_pid = task_tgid_nr_ns(current,
task_active_pid_ns(t));
- q->info.si_uid = from_kuid_munged(current_user_ns(), current_uid());
+ rcu_read_lock();
+ q->info.si_uid =
+ from_kuid_munged(task_cred_xxx(t, user_ns),
+ current_uid());
+ rcu_read_unlock();
break;
case (unsigned long) SEND_SIG_PRIV:
clear_siginfo(&q->info);
@@ -1093,30 +1134,24 @@
break;
default:
copy_siginfo(&q->info, info);
- if (from_ancestor_ns)
- q->info.si_pid = 0;
break;
}
-
- userns_fixup_signal_uid(&q->info, t);
-
- } else if (!is_si_special(info)) {
- if (sig >= SIGRTMIN && info->si_code != SI_USER) {
- /*
- * Queue overflow, abort. We may abort if the
- * signal was rt and sent by user using something
- * other than kill().
- */
- result = TRACE_SIGNAL_OVERFLOW_FAIL;
- ret = -EAGAIN;
- goto ret;
- } else {
- /*
- * This is a silent loss of information. We still
- * send the signal, but the *info bits are lost.
- */
- result = TRACE_SIGNAL_LOSE_INFO;
- }
+ } else if (!is_si_special(info) &&
+ sig >= SIGRTMIN && info->si_code != SI_USER) {
+ /*
+ * Queue overflow, abort. We may abort if the
+ * signal was rt and sent by user using something
+ * other than kill().
+ */
+ result = TRACE_SIGNAL_OVERFLOW_FAIL;
+ ret = -EAGAIN;
+ goto ret;
+ } else {
+ /*
+ * This is a silent loss of information. We still
+ * send the signal, but the *info bits are lost.
+ */
+ result = TRACE_SIGNAL_LOSE_INFO;
}
out_set:
@@ -1143,17 +1178,62 @@
return ret;
}
-static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
+static inline bool has_si_pid_and_uid(struct kernel_siginfo *info)
+{
+ bool ret = false;
+ switch (siginfo_layout(info->si_signo, info->si_code)) {
+ case SIL_KILL:
+ case SIL_CHLD:
+ case SIL_RT:
+ ret = true;
+ break;
+ case SIL_TIMER:
+ case SIL_POLL:
+ case SIL_FAULT:
+ case SIL_FAULT_MCEERR:
+ case SIL_FAULT_BNDERR:
+ case SIL_FAULT_PKUERR:
+ case SIL_SYS:
+ ret = false;
+ break;
+ }
+ return ret;
+}
+
+static int send_signal(int sig, struct kernel_siginfo *info, struct task_struct *t,
enum pid_type type)
{
- int from_ancestor_ns = 0;
+ /* Should SIGKILL or SIGSTOP be received by a pid namespace init? */
+ bool force = false;
-#ifdef CONFIG_PID_NS
- from_ancestor_ns = si_fromuser(info) &&
- !task_pid_nr_ns(current, task_active_pid_ns(t));
-#endif
+ if (info == SEND_SIG_NOINFO) {
+ /* Force if sent from an ancestor pid namespace */
+ force = !task_pid_nr_ns(current, task_active_pid_ns(t));
+ } else if (info == SEND_SIG_PRIV) {
+ /* Don't ignore kernel generated signals */
+ force = true;
+ } else if (has_si_pid_and_uid(info)) {
+ /* SIGKILL and SIGSTOP is special or has ids */
+ struct user_namespace *t_user_ns;
- return __send_signal(sig, info, t, type, from_ancestor_ns);
+ rcu_read_lock();
+ t_user_ns = task_cred_xxx(t, user_ns);
+ if (current_user_ns() != t_user_ns) {
+ kuid_t uid = make_kuid(current_user_ns(), info->si_uid);
+ info->si_uid = from_kuid_munged(t_user_ns, uid);
+ }
+ rcu_read_unlock();
+
+ /* A kernel generated signal? */
+ force = (info->si_code == SI_KERNEL);
+
+ /* From an ancestor pid namespace? */
+ if (!task_pid_nr_ns(current, task_active_pid_ns(t))) {
+ info->si_pid = 0;
+ force = true;
+ }
+ }
+ return __send_signal(sig, info, t, type, force);
}
static void print_fatal_signal(int signr)
@@ -1190,18 +1270,12 @@
__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;
@@ -1226,12 +1300,13 @@
* We don't want to have recursive SIGSEGV's etc, for example,
* that is why we also clear SIGNAL_UNKILLABLE.
*/
-int
-force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
+static int
+force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t)
{
unsigned long int flags;
int ret, blocked, ignored;
struct k_sigaction *action;
+ int sig = info->si_signo;
spin_lock_irqsave(&t->sighand->siglock, flags);
action = &t->sighand->action[sig-1];
@@ -1250,12 +1325,17 @@
*/
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;
}
+int force_sig_info(struct kernel_siginfo *info)
+{
+ return force_sig_info_to_task(info, current);
+}
+
/*
* Nuke all other threads in the group.
*/
@@ -1315,8 +1395,8 @@
/*
* 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 +1415,7 @@
* 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 +1430,7 @@
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 +1452,7 @@
}
}
-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();
@@ -1392,13 +1472,44 @@
uid_eq(cred->uid, pcred->uid);
}
-/* 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,
- const struct cred *cred)
+/*
+ * The usb asyncio usage of siginfo is wrong. The glibc support
+ * for asyncio which uses SI_ASYNCIO assumes the layout is SIL_RT.
+ * AKA after the generic fields:
+ * kernel_pid_t si_pid;
+ * kernel_uid32_t si_uid;
+ * sigval_t si_value;
+ *
+ * Unfortunately when usb generates SI_ASYNCIO it assumes the layout
+ * after the generic fields is:
+ * void __user *si_addr;
+ *
+ * This is a practical problem when there is a 64bit big endian kernel
+ * and a 32bit userspace. As the 32bit address will encoded in the low
+ * 32bits of the pointer. Those low 32bits will be stored at higher
+ * address than appear in a 32 bit pointer. So userspace will not
+ * see the address it was expecting for it's completions.
+ *
+ * There is nothing in the encoding that can allow
+ * copy_siginfo_to_user32 to detect this confusion of formats, so
+ * handle this by requiring the caller of kill_pid_usb_asyncio to
+ * notice when this situration takes place and to store the 32bit
+ * pointer in sival_int, instead of sival_addr of the sigval_t addr
+ * parameter.
+ */
+int kill_pid_usb_asyncio(int sig, int errno, sigval_t addr,
+ struct pid *pid, const struct cred *cred)
{
- int ret = -EINVAL;
+ struct kernel_siginfo info;
struct task_struct *p;
unsigned long flags;
+ int ret = -EINVAL;
+
+ clear_siginfo(&info);
+ info.si_signo = sig;
+ info.si_errno = errno;
+ info.si_code = SI_ASYNCIO;
+ *((sigval_t *)&info.si_pid) = addr;
if (!valid_signal(sig))
return ret;
@@ -1409,17 +1520,17 @@
ret = -ESRCH;
goto out_unlock;
}
- if (si_fromuser(info) && !kill_as_cred_perm(cred, p)) {
+ if (!kill_as_cred_perm(cred, p)) {
ret = -EPERM;
goto out_unlock;
}
- ret = security_task_kill(p, info, sig, cred);
+ ret = security_task_kill(p, &info, sig, cred);
if (ret)
goto out_unlock;
if (sig) {
if (lock_task_sighand(p, &flags)) {
- ret = __send_signal(sig, info, p, PIDTYPE_TGID, 0);
+ ret = __send_signal(sig, &info, p, PIDTYPE_TGID, false);
unlock_task_sighand(p, &flags);
} else
ret = -ESRCH;
@@ -1428,7 +1539,7 @@
rcu_read_unlock();
return ret;
}
-EXPORT_SYMBOL_GPL(kill_pid_info_as_cred);
+EXPORT_SYMBOL_GPL(kill_pid_usb_asyncio);
/*
* kill_something_info() interprets pid in interesting ways just like kill(2).
@@ -1437,7 +1548,7 @@
* 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 +1592,7 @@
* 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 +1603,7 @@
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 +1613,21 @@
{
return send_sig_info(sig, __si_special(priv), p);
}
+EXPORT_SYMBOL(send_sig);
-void force_sig(int sig, struct task_struct *p)
+void force_sig(int sig)
{
- force_sig_info(sig, SEND_SIG_PRIV, p);
+ struct kernel_siginfo info;
+
+ clear_siginfo(&info);
+ info.si_signo = sig;
+ info.si_errno = 0;
+ info.si_code = SI_KERNEL;
+ info.si_pid = 0;
+ info.si_uid = 0;
+ force_sig_info(&info);
}
+EXPORT_SYMBOL(force_sig);
/*
* When things go south during signal handling, we
@@ -1513,23 +1635,25 @@
* the problem was already a SIGSEGV, we'll want to
* make sure we don't even try to deliver the signal..
*/
-void force_sigsegv(int sig, struct task_struct *p)
+void force_sigsegv(int sig)
{
+ struct task_struct *p = current;
+
if (sig == SIGSEGV) {
unsigned long flags;
spin_lock_irqsave(&p->sighand->siglock, flags);
p->sighand->action[sig - 1].sa.sa_handler = SIG_DFL;
spin_unlock_irqrestore(&p->sighand->siglock, flags);
}
- force_sig(SIGSEGV, p);
+ force_sig(SIGSEGV);
}
-int force_sig_fault(int sig, int code, void __user *addr
+int force_sig_fault_to_task(int sig, int code, void __user *addr
___ARCH_SI_TRAPNO(int trapno)
___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;
@@ -1544,7 +1668,16 @@
info.si_flags = flags;
info.si_isr = isr;
#endif
- return force_sig_info(info.si_signo, &info, t);
+ return force_sig_info_to_task(&info, t);
+}
+
+int force_sig_fault(int sig, int code, void __user *addr
+ ___ARCH_SI_TRAPNO(int trapno)
+ ___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr))
+{
+ return force_sig_fault_to_task(sig, code, addr
+ ___ARCH_SI_TRAPNO(trapno)
+ ___ARCH_SI_IA64(imm, flags, isr), current);
}
int send_sig_fault(int sig, int code, void __user *addr
@@ -1552,7 +1685,7 @@
___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;
@@ -1570,9 +1703,9 @@
return send_sig_info(info.si_signo, &info, t);
}
-int force_sig_mceerr(int code, void __user *addr, short lsb, struct task_struct *t)
+int force_sig_mceerr(int code, void __user *addr, short lsb)
{
- struct siginfo info;
+ struct kernel_siginfo info;
WARN_ON((code != BUS_MCEERR_AO) && (code != BUS_MCEERR_AR));
clear_siginfo(&info);
@@ -1581,12 +1714,12 @@
info.si_code = code;
info.si_addr = addr;
info.si_addr_lsb = lsb;
- return force_sig_info(info.si_signo, &info, t);
+ return force_sig_info(&info);
}
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 +1734,7 @@
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;
@@ -1610,13 +1743,13 @@
info.si_addr = addr;
info.si_lower = lower;
info.si_upper = upper;
- return force_sig_info(info.si_signo, &info, current);
+ return force_sig_info(&info);
}
#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;
@@ -1624,7 +1757,7 @@
info.si_code = SEGV_PKUERR;
info.si_addr = addr;
info.si_pkey = pkey;
- return force_sig_info(info.si_signo, &info, current);
+ return force_sig_info(&info);
}
#endif
@@ -1633,14 +1766,14 @@
*/
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;
info.si_errno = errno;
info.si_code = TRAP_HWBKPT;
info.si_addr = addr;
- return force_sig_info(info.si_signo, &info, current);
+ return force_sig_info(&info);
}
int kill_pgrp(struct pid *pid, int sig, int priv)
@@ -1753,6 +1886,15 @@
return ret;
}
+static void do_notify_pidfd(struct task_struct *task)
+{
+ struct pid *pid;
+
+ WARN_ON(task->exit_state == 0);
+ pid = task_pid(task);
+ wake_up_all(&pid->wait_pidfd);
+}
+
/*
* Let a parent know about the death of a child.
* For a stopped/continued status change, use do_notify_parent_cldstop instead.
@@ -1762,7 +1904,7 @@
*/
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;
@@ -1776,6 +1918,9 @@
BUG_ON(!tsk->ptrace &&
(tsk->group_leader != tsk || !thread_group_empty(tsk)));
+ /* Wake up all pidfd waiters */
+ do_notify_pidfd(tsk);
+
if (sig != SIGCHLD) {
/*
* This is only possible if parent == real_parent.
@@ -1867,7 +2012,7 @@
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 +2112,7 @@
* 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)
{
@@ -2060,8 +2205,10 @@
*/
preempt_disable();
read_unlock(&tasklist_lock);
+ cgroup_enter_frozen();
preempt_enable_no_resched();
freezable_schedule();
+ cgroup_leave_frozen(true);
} else {
/*
* By the time we got the lock, our tracer went away.
@@ -2104,7 +2251,7 @@
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;
@@ -2239,6 +2386,7 @@
}
/* Now we don't run again until woken by SIGCONT or SIGKILL */
+ cgroup_enter_frozen();
freezable_schedule();
return true;
} else {
@@ -2285,7 +2433,44 @@
}
}
-static int ptrace_signal(int signr, siginfo_t *info)
+/**
+ * do_freezer_trap - handle the freezer jobctl trap
+ *
+ * Puts the task into frozen state, if only the task is not about to quit.
+ * In this case it drops JOBCTL_TRAP_FREEZE.
+ *
+ * CONTEXT:
+ * Must be called with @current->sighand->siglock held,
+ * which is always released before returning.
+ */
+static void do_freezer_trap(void)
+ __releases(¤t->sighand->siglock)
+{
+ /*
+ * If there are other trap bits pending except JOBCTL_TRAP_FREEZE,
+ * let's make another loop to give it a chance to be handled.
+ * In any case, we'll return back.
+ */
+ if ((current->jobctl & (JOBCTL_PENDING_MASK | JOBCTL_TRAP_FREEZE)) !=
+ JOBCTL_TRAP_FREEZE) {
+ spin_unlock_irq(¤t->sighand->siglock);
+ return;
+ }
+
+ /*
+ * Now we're sure that there is no pending fatal signal and no
+ * pending traps. Clear TIF_SIGPENDING to not get out of schedule()
+ * immediately (if there is a non-fatal signal pending), and
+ * put the task into sleep.
+ */
+ __set_current_state(TASK_INTERRUPTIBLE);
+ clear_thread_flag(TIF_SIGPENDING);
+ spin_unlock_irq(¤t->sighand->siglock);
+ cgroup_enter_frozen();
+ freezable_schedule();
+}
+
+static int ptrace_signal(int signr, kernel_siginfo_t *info)
{
/*
* We do not check sig_kernel_stop(signr) but set this marker
@@ -2326,7 +2511,7 @@
/* 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;
}
@@ -2390,6 +2575,16 @@
goto relock;
}
+ /* Has this task already been marked for death? */
+ if (signal_group_exit(signal)) {
+ ksig->info.si_signo = signr = SIGKILL;
+ sigdelset(¤t->pending.signal, SIGKILL);
+ trace_signal_deliver(SIGKILL, SEND_SIG_NOINFO,
+ &sighand->action[SIGKILL - 1]);
+ recalc_sigpending();
+ goto fatal;
+ }
+
for (;;) {
struct k_sigaction *ka;
@@ -2397,13 +2592,36 @@
do_signal_stop(0))
goto relock;
- if (unlikely(current->jobctl & JOBCTL_TRAP_MASK)) {
- do_jobctl_trap();
- spin_unlock_irq(&sighand->siglock);
+ if (unlikely(current->jobctl &
+ (JOBCTL_TRAP_MASK | JOBCTL_TRAP_FREEZE))) {
+ if (current->jobctl & JOBCTL_TRAP_MASK) {
+ do_jobctl_trap();
+ spin_unlock_irq(&sighand->siglock);
+ } else if (current->jobctl & JOBCTL_TRAP_FREEZE)
+ do_freezer_trap();
+
goto relock;
}
- signr = dequeue_signal(current, ¤t->blocked, &ksig->info);
+ /*
+ * If the task is leaving the frozen state, let's update
+ * cgroup counters and reset the frozen bit.
+ */
+ if (unlikely(cgroup_task_frozen(current))) {
+ spin_unlock_irq(&sighand->siglock);
+ cgroup_leave_frozen(false);
+ goto relock;
+ }
+
+ /*
+ * Signals generated by the execution of an instruction
+ * need to be delivered before any other pending signals
+ * so that the instruction pointer in the signal stack
+ * frame points to the faulting instruction.
+ */
+ signr = dequeue_synchronous_signal(&ksig->info);
+ if (!signr)
+ signr = dequeue_signal(current, ¤t->blocked, &ksig->info);
if (!signr)
break; /* will return 0 */
@@ -2485,7 +2703,10 @@
continue;
}
+ fatal:
spin_unlock_irq(&sighand->siglock);
+ if (unlikely(cgroup_task_frozen(current)))
+ cgroup_leave_frozen(true);
/*
* Anything else is fatal, maybe with a core dump.
@@ -2549,7 +2770,7 @@
void signal_setup_done(int failed, struct ksignal *ksig, int stepping)
{
if (failed)
- force_sigsegv(ksig->sig, current);
+ force_sigsegv(ksig->sig);
else
signal_delivered(ksig, stepping);
}
@@ -2636,14 +2857,6 @@
}
}
-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 +2950,55 @@
__set_current_blocked(&newset);
return 0;
}
+EXPORT_SYMBOL(sigprocmask);
+
+/*
+ * The api helps set app-provided sigmasks.
+ *
+ * This is useful for syscalls such as ppoll, pselect, io_pgetevents and
+ * epoll_pwait where a new sigmask is passed from userland for the syscalls.
+ *
+ * Note that it does set_restore_sigmask() in advance, so it must be always
+ * paired with restore_saved_sigmask_unless() before return from syscall.
+ */
+int set_user_sigmask(const sigset_t __user *umask, size_t sigsetsize)
+{
+ sigset_t kmask;
+
+ if (!umask)
+ return 0;
+ if (sigsetsize != sizeof(sigset_t))
+ return -EINVAL;
+ if (copy_from_user(&kmask, umask, sizeof(sigset_t)))
+ return -EFAULT;
+
+ set_restore_sigmask();
+ current->saved_sigmask = current->blocked;
+ set_current_blocked(&kmask);
+
+ return 0;
+}
+
+#ifdef CONFIG_COMPAT
+int set_compat_user_sigmask(const compat_sigset_t __user *umask,
+ size_t sigsetsize)
+{
+ sigset_t kmask;
+
+ if (!umask)
+ return 0;
+ if (sigsetsize != sizeof(compat_sigset_t))
+ return -EINVAL;
+ if (get_compat_sigset(&kmask, umask))
+ return -EFAULT;
+
+ set_restore_sigmask();
+ current->saved_sigmask = current->blocked;
+ set_current_blocked(&kmask);
+
+ return 0;
+}
+#endif
/**
* sys_rt_sigprocmask - change the list of currently blocked signals
@@ -2847,27 +3109,48 @@
}
#endif
+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 +3175,69 @@
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)
{
- if (copy_to_user(to, from , sizeof(struct siginfo)))
+ return ((char __user *)info) + sizeof(struct kernel_siginfo);
+}
+
+int copy_siginfo_to_user(siginfo_t __user *to, const kernel_siginfo_t *from)
+{
+ 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;
@@ -2991,7 +3321,97 @@
return 0;
}
-int copy_siginfo_from_user32(struct siginfo *to,
+static int post_copy_siginfo_from_user32(kernel_siginfo_t *to,
+ const struct compat_siginfo *from)
+{
+ 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)) {
+ case SIL_KILL:
+ 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;
+ break;
+ case SIL_POLL:
+ to->si_band = from->si_band;
+ to->si_fd = from->si_fd;
+ break;
+ case SIL_FAULT:
+ to->si_addr = compat_ptr(from->si_addr);
+#ifdef __ARCH_SI_TRAPNO
+ to->si_trapno = from->si_trapno;
+#endif
+ break;
+ case SIL_FAULT_MCEERR:
+ to->si_addr = compat_ptr(from->si_addr);
+#ifdef __ARCH_SI_TRAPNO
+ to->si_trapno = from->si_trapno;
+#endif
+ to->si_addr_lsb = from->si_addr_lsb;
+ break;
+ case SIL_FAULT_BNDERR:
+ to->si_addr = compat_ptr(from->si_addr);
+#ifdef __ARCH_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);
+ break;
+ case SIL_FAULT_PKUERR:
+ to->si_addr = compat_ptr(from->si_addr);
+#ifdef __ARCH_SI_TRAPNO
+ to->si_trapno = from->si_trapno;
+#endif
+ 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;
+#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;
+ } else
+#endif
+ {
+ 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;
+ 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;
+ 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;
@@ -2999,79 +3419,7 @@
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)) {
- case SIL_KILL:
- 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;
- break;
- case SIL_POLL:
- to->si_band = from.si_band;
- to->si_fd = from.si_fd;
- break;
- case SIL_FAULT:
- to->si_addr = compat_ptr(from.si_addr);
-#ifdef __ARCH_SI_TRAPNO
- to->si_trapno = from.si_trapno;
-#endif
- break;
- case SIL_FAULT_MCEERR:
- to->si_addr = compat_ptr(from.si_addr);
-#ifdef __ARCH_SI_TRAPNO
- to->si_trapno = from.si_trapno;
-#endif
- to->si_addr_lsb = from.si_addr_lsb;
- break;
- case SIL_FAULT_BNDERR:
- to->si_addr = compat_ptr(from.si_addr);
-#ifdef __ARCH_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);
- break;
- case SIL_FAULT_PKUERR:
- to->si_addr = compat_ptr(from.si_addr);
-#ifdef __ARCH_SI_TRAPNO
- to->si_trapno = from.si_trapno;
-#endif
- 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;
-#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;
- } else
-#endif
- {
- 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;
- 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;
- break;
- }
- return 0;
+ return post_copy_siginfo_from_user32(to, &from);
}
#endif /* CONFIG_COMPAT */
@@ -3081,8 +3429,8 @@
* @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,
- const struct timespec *ts)
+static int do_sigtimedwait(const sigset_t *which, kernel_siginfo_t *info,
+ const struct timespec64 *ts)
{
ktime_t *to = NULL, timeout = KTIME_MAX;
struct task_struct *tsk = current;
@@ -3090,9 +3438,9 @@
int sig, ret = 0;
if (ts) {
- if (!timespec_valid(ts))
+ if (!timespec64_valid(ts))
return -EINVAL;
- timeout = timespec_to_ktime(*ts);
+ timeout = timespec64_to_ktime(*ts);
to = &timeout;
}
@@ -3140,12 +3488,13 @@
* @sigsetsize: size of sigset_t type
*/
SYSCALL_DEFINE4(rt_sigtimedwait, const sigset_t __user *, uthese,
- siginfo_t __user *, uinfo, const struct timespec __user *, uts,
+ siginfo_t __user *, uinfo,
+ const struct __kernel_timespec __user *, uts,
size_t, sigsetsize)
{
sigset_t these;
- struct timespec ts;
- siginfo_t info;
+ struct timespec64 ts;
+ kernel_siginfo_t info;
int ret;
/* XXX: Don't preclude handling different sized sigset_t's. */
@@ -3156,7 +3505,7 @@
return -EFAULT;
if (uts) {
- if (copy_from_user(&ts, uts, sizeof(ts)))
+ if (get_timespec64(&ts, uts))
return -EFAULT;
}
@@ -3170,14 +3519,47 @@
return ret;
}
+#ifdef CONFIG_COMPAT_32BIT_TIME
+SYSCALL_DEFINE4(rt_sigtimedwait_time32, const sigset_t __user *, uthese,
+ siginfo_t __user *, uinfo,
+ const struct old_timespec32 __user *, uts,
+ size_t, sigsetsize)
+{
+ sigset_t these;
+ struct timespec64 ts;
+ kernel_siginfo_t info;
+ int ret;
+
+ if (sigsetsize != sizeof(sigset_t))
+ return -EINVAL;
+
+ if (copy_from_user(&these, uthese, sizeof(these)))
+ return -EFAULT;
+
+ if (uts) {
+ if (get_old_timespec32(&ts, uts))
+ return -EFAULT;
+ }
+
+ ret = do_sigtimedwait(&these, &info, uts ? &ts : NULL);
+
+ if (ret > 0 && uinfo) {
+ if (copy_siginfo_to_user(uinfo, &info))
+ ret = -EFAULT;
+ }
+
+ return ret;
+}
+#endif
+
#ifdef CONFIG_COMPAT
-COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait, compat_sigset_t __user *, uthese,
+COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait_time64, compat_sigset_t __user *, uthese,
struct compat_siginfo __user *, uinfo,
- struct compat_timespec __user *, uts, compat_size_t, sigsetsize)
+ struct __kernel_timespec __user *, uts, compat_size_t, sigsetsize)
{
sigset_t s;
- struct timespec t;
- siginfo_t info;
+ struct timespec64 t;
+ kernel_siginfo_t info;
long ret;
if (sigsetsize != sizeof(sigset_t))
@@ -3187,7 +3569,38 @@
return -EFAULT;
if (uts) {
- if (compat_get_timespec(&t, uts))
+ if (get_timespec64(&t, uts))
+ return -EFAULT;
+ }
+
+ ret = do_sigtimedwait(&s, &info, uts ? &t : NULL);
+
+ if (ret > 0 && uinfo) {
+ if (copy_siginfo_to_user32(uinfo, &info))
+ ret = -EFAULT;
+ }
+
+ return ret;
+}
+
+#ifdef CONFIG_COMPAT_32BIT_TIME
+COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait_time32, compat_sigset_t __user *, uthese,
+ struct compat_siginfo __user *, uinfo,
+ struct old_timespec32 __user *, uts, compat_size_t, sigsetsize)
+{
+ sigset_t s;
+ struct timespec64 t;
+ kernel_siginfo_t info;
+ long ret;
+
+ if (sigsetsize != sizeof(sigset_t))
+ return -EINVAL;
+
+ if (get_compat_sigset(&s, uthese))
+ return -EFAULT;
+
+ if (uts) {
+ if (get_old_timespec32(&t, uts))
return -EFAULT;
}
@@ -3201,6 +3614,17 @@
return ret;
}
#endif
+#endif
+
+static inline void prepare_kill_siginfo(int sig, struct kernel_siginfo *info)
+{
+ clear_siginfo(info);
+ info->si_signo = sig;
+ info->si_errno = 0;
+ info->si_code = SI_USER;
+ info->si_pid = task_tgid_vnr(current);
+ info->si_uid = from_kuid_munged(current_user_ns(), current_uid());
+}
/**
* sys_kill - send a signal to a process
@@ -3209,20 +3633,132 @@
*/
SYSCALL_DEFINE2(kill, pid_t, pid, int, sig)
{
- struct siginfo info;
+ struct kernel_siginfo info;
- clear_siginfo(&info);
- info.si_signo = sig;
- info.si_errno = 0;
- info.si_code = SI_USER;
- info.si_pid = task_tgid_vnr(current);
- info.si_uid = from_kuid_munged(current_user_ns(), current_uid());
+ prepare_kill_siginfo(sig, &info);
return kill_something_info(sig, &info, pid);
}
+/*
+ * Verify that the signaler and signalee either are in the same pid namespace
+ * or that the signaler's pid namespace is an ancestor of the signalee's pid
+ * namespace.
+ */
+static bool access_pidfd_pidns(struct pid *pid)
+{
+ struct pid_namespace *active = task_active_pid_ns(current);
+ struct pid_namespace *p = ns_of_pid(pid);
+
+ for (;;) {
+ if (!p)
+ return false;
+ if (p == active)
+ break;
+ p = p->parent;
+ }
+
+ return true;
+}
+
+static int copy_siginfo_from_user_any(kernel_siginfo_t *kinfo, siginfo_t *info)
+{
+#ifdef CONFIG_COMPAT
+ /*
+ * Avoid hooking up compat syscalls and instead handle necessary
+ * conversions here. Note, this is a stop-gap measure and should not be
+ * considered a generic solution.
+ */
+ if (in_compat_syscall())
+ return copy_siginfo_from_user32(
+ kinfo, (struct compat_siginfo __user *)info);
+#endif
+ return copy_siginfo_from_user(kinfo, info);
+}
+
+static struct pid *pidfd_to_pid(const struct file *file)
+{
+ struct pid *pid;
+
+ pid = pidfd_pid(file);
+ if (!IS_ERR(pid))
+ return pid;
+
+ return tgid_pidfd_to_pid(file);
+}
+
+/**
+ * sys_pidfd_send_signal - Signal a process through a pidfd
+ * @pidfd: file descriptor of the process
+ * @sig: signal to send
+ * @info: signal info
+ * @flags: future flags
+ *
+ * The syscall currently only signals via PIDTYPE_PID which covers
+ * kill(<positive-pid>, <signal>. It does not signal threads or process
+ * groups.
+ * In order to extend the syscall to threads and process groups the @flags
+ * argument should be used. In essence, the @flags argument will determine
+ * what is signaled and not the file descriptor itself. Put in other words,
+ * grouping is a property of the flags argument not a property of the file
+ * descriptor.
+ *
+ * Return: 0 on success, negative errno on failure
+ */
+SYSCALL_DEFINE4(pidfd_send_signal, int, pidfd, int, sig,
+ siginfo_t __user *, info, unsigned int, flags)
+{
+ int ret;
+ struct fd f;
+ struct pid *pid;
+ kernel_siginfo_t kinfo;
+
+ /* Enforce flags be set to 0 until we add an extension. */
+ if (flags)
+ return -EINVAL;
+
+ f = fdget(pidfd);
+ if (!f.file)
+ return -EBADF;
+
+ /* Is this a pidfd? */
+ pid = pidfd_to_pid(f.file);
+ if (IS_ERR(pid)) {
+ ret = PTR_ERR(pid);
+ goto err;
+ }
+
+ ret = -EINVAL;
+ if (!access_pidfd_pidns(pid))
+ goto err;
+
+ if (info) {
+ ret = copy_siginfo_from_user_any(&kinfo, info);
+ if (unlikely(ret))
+ goto err;
+
+ ret = -EINVAL;
+ if (unlikely(sig != kinfo.si_signo))
+ goto err;
+
+ /* Only allow sending arbitrary signals to yourself. */
+ ret = -EPERM;
+ if ((task_pid(current) != pid) &&
+ (kinfo.si_code >= 0 || kinfo.si_code == SI_TKILL))
+ goto err;
+ } else {
+ prepare_kill_siginfo(sig, &kinfo);
+ }
+
+ ret = kill_pid_info(sig, &kinfo, pid);
+
+err:
+ fdput(f);
+ return ret;
+}
+
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 +3789,7 @@
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 +3836,7 @@
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 +3845,6 @@
(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 +3858,10 @@
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 +3871,15 @@
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 +3892,16 @@
(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 +3912,10 @@
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
@@ -3774,7 +4306,7 @@
if (act) {
old_sigset_t mask;
- if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
+ if (!access_ok(act, sizeof(*act)) ||
__get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
__get_user(new_ka.sa.sa_restorer, &act->sa_restorer) ||
__get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
@@ -3789,7 +4321,7 @@
ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
if (!ret && oact) {
- if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
+ if (!access_ok(oact, sizeof(*oact)) ||
__put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
__put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) ||
__put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
@@ -3811,7 +4343,7 @@
compat_uptr_t handler, restorer;
if (act) {
- if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
+ if (!access_ok(act, sizeof(*act)) ||
__get_user(handler, &act->sa_handler) ||
__get_user(restorer, &act->sa_restorer) ||
__get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
@@ -3829,7 +4361,7 @@
ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
if (!ret && oact) {
- if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
+ if (!access_ok(oact, sizeof(*oact)) ||
__put_user(ptr_to_compat(old_ka.sa.sa_handler),
&oact->sa_handler) ||
__put_user(ptr_to_compat(old_ka.sa.sa_restorer),
@@ -3966,12 +4498,78 @@
return NULL;
}
+static inline void siginfo_buildtime_checks(void)
+{
+ 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
+
+ /* usb asyncio */
+ BUILD_BUG_ON(offsetof(struct siginfo, si_pid) !=
+ offsetof(struct siginfo, si_addr));
+ if (sizeof(int) == sizeof(void __user *)) {
+ BUILD_BUG_ON(sizeof_field(struct siginfo, si_pid) !=
+ sizeof(void __user *));
+ } else {
+ BUILD_BUG_ON((sizeof_field(struct siginfo, si_pid) +
+ sizeof_field(struct siginfo, si_uid)) !=
+ sizeof(void __user *));
+ BUILD_BUG_ON(offsetofend(struct siginfo, si_pid) !=
+ offsetof(struct siginfo, si_uid));
+ }
+#ifdef CONFIG_COMPAT
+ BUILD_BUG_ON(offsetof(struct compat_siginfo, si_pid) !=
+ offsetof(struct compat_siginfo, si_addr));
+ BUILD_BUG_ON(sizeof_field(struct compat_siginfo, si_pid) !=
+ sizeof(compat_uptr_t));
+ BUILD_BUG_ON(sizeof_field(struct compat_siginfo, si_pid) !=
+ sizeof_field(struct siginfo, si_pid));
+#endif
+}
+
void __init signals_init(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);
+ siginfo_buildtime_checks();
sigqueue_cachep = KMEM_CACHE(sigqueue, SLAB_PANIC);
}