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-rw-r--r--kernel/signal.c244
1 files changed, 162 insertions, 82 deletions
diff --git a/kernel/signal.c b/kernel/signal.c
index 45b4c1ffe14e..8dcd8825b2de 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -39,6 +39,7 @@
#include <linux/compat.h>
#include <linux/cn_proc.h>
#include <linux/compiler.h>
+#include <linux/posix-timers.h>
#define CREATE_TRACE_POINTS
#include <trace/events/signal.h>
@@ -637,7 +638,7 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
* about to disable them again anyway.
*/
spin_unlock(&tsk->sighand->siglock);
- do_schedule_next_timer(info);
+ posixtimer_rearm(info);
spin_lock(&tsk->sighand->siglock);
}
#endif
@@ -1193,7 +1194,11 @@ force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
recalc_sigpending_and_wake(t);
}
}
- if (action->sa.sa_handler == SIG_DFL)
+ /*
+ * Don't clear SIGNAL_UNKILLABLE for traced tasks, users won't expect
+ * debugging to leave init killable.
+ */
+ if (action->sa.sa_handler == SIG_DFL && !t->ptrace)
t->signal->flags &= ~SIGNAL_UNKILLABLE;
ret = specific_send_sig_info(sig, info, t);
spin_unlock_irqrestore(&t->sighand->siglock, flags);
@@ -1401,6 +1406,10 @@ static int kill_something_info(int sig, struct siginfo *info, pid_t pid)
return ret;
}
+ /* -INT_MIN is undefined. Exclude this case to avoid a UBSAN warning */
+ if (pid == INT_MIN)
+ return -ESRCH;
+
read_lock(&tasklist_lock);
if (pid != -1) {
ret = __kill_pgrp_info(sig, info,
@@ -2100,7 +2109,6 @@ static void do_jobctl_trap(void)
static int ptrace_signal(int signr, siginfo_t *info)
{
- ptrace_signal_deliver();
/*
* We do not check sig_kernel_stop(signr) but set this marker
* unconditionally because we do not know whether debugger will
@@ -2678,6 +2686,51 @@ COMPAT_SYSCALL_DEFINE2(rt_sigpending, compat_sigset_t __user *, uset,
}
#endif
+enum siginfo_layout siginfo_layout(int 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 },
+#ifdef __ARCH_SIGSYS
+ [SIGSYS] = { NSIGSYS, SIL_SYS },
+#endif
+ };
+ if ((sig < ARRAY_SIZE(filter)) && (si_code <= filter[sig].limit))
+ layout = filter[sig].layout;
+ else if (si_code <= NSIGPOLL)
+ layout = SIL_POLL;
+ } else {
+ if (si_code == SI_TIMER)
+ layout = SIL_TIMER;
+ else if (si_code == SI_SIGIO)
+ layout = SIL_POLL;
+ else if (si_code < 0)
+ layout = SIL_RT;
+ /* Tests to support buggy kernel ABIs */
+#ifdef TRAP_FIXME
+ if ((sig == SIGTRAP) && (si_code == TRAP_FIXME))
+ layout = SIL_FAULT;
+#endif
+#ifdef FPE_FIXME
+ if ((sig == SIGFPE) && (si_code == FPE_FIXME))
+ layout = SIL_FAULT;
+#endif
+ }
+ return layout;
+}
+
#ifndef HAVE_ARCH_COPY_SIGINFO_TO_USER
int copy_siginfo_to_user(siginfo_t __user *to, const siginfo_t *from)
@@ -2700,22 +2753,20 @@ int copy_siginfo_to_user(siginfo_t __user *to, const siginfo_t *from)
*/
err = __put_user(from->si_signo, &to->si_signo);
err |= __put_user(from->si_errno, &to->si_errno);
- err |= __put_user((short)from->si_code, &to->si_code);
- switch (from->si_code & __SI_MASK) {
- case __SI_KILL:
+ err |= __put_user(from->si_code, &to->si_code);
+ switch (siginfo_layout(from->si_signo, from->si_code)) {
+ case SIL_KILL:
err |= __put_user(from->si_pid, &to->si_pid);
err |= __put_user(from->si_uid, &to->si_uid);
break;
- case __SI_TIMER:
- err |= __put_user(from->si_tid, &to->si_tid);
- err |= __put_user(from->si_overrun, &to->si_overrun);
- err |= __put_user(from->si_ptr, &to->si_ptr);
+ case SIL_TIMER:
+ /* Unreached SI_TIMER is negative */
break;
- case __SI_POLL:
+ case SIL_POLL:
err |= __put_user(from->si_band, &to->si_band);
err |= __put_user(from->si_fd, &to->si_fd);
break;
- case __SI_FAULT:
+ case SIL_FAULT:
err |= __put_user(from->si_addr, &to->si_addr);
#ifdef __ARCH_SI_TRAPNO
err |= __put_user(from->si_trapno, &to->si_trapno);
@@ -2740,30 +2791,25 @@ int copy_siginfo_to_user(siginfo_t __user *to, const siginfo_t *from)
err |= __put_user(from->si_pkey, &to->si_pkey);
#endif
break;
- case __SI_CHLD:
+ case SIL_CHLD:
err |= __put_user(from->si_pid, &to->si_pid);
err |= __put_user(from->si_uid, &to->si_uid);
err |= __put_user(from->si_status, &to->si_status);
err |= __put_user(from->si_utime, &to->si_utime);
err |= __put_user(from->si_stime, &to->si_stime);
break;
- case __SI_RT: /* This is not generated by the kernel as of now. */
- case __SI_MESGQ: /* But this is */
+ case SIL_RT:
err |= __put_user(from->si_pid, &to->si_pid);
err |= __put_user(from->si_uid, &to->si_uid);
err |= __put_user(from->si_ptr, &to->si_ptr);
break;
#ifdef __ARCH_SIGSYS
- case __SI_SYS:
+ case SIL_SYS:
err |= __put_user(from->si_call_addr, &to->si_call_addr);
err |= __put_user(from->si_syscall, &to->si_syscall);
err |= __put_user(from->si_arch, &to->si_arch);
break;
#endif
- default: /* this is just in case for now ... */
- err |= __put_user(from->si_pid, &to->si_pid);
- err |= __put_user(from->si_uid, &to->si_uid);
- break;
}
return err;
}
@@ -2776,7 +2822,7 @@ int copy_siginfo_to_user(siginfo_t __user *to, const siginfo_t *from)
* @info: if non-null, the signal's siginfo is returned here
* @ts: upper bound on process time suspension
*/
-int do_sigtimedwait(const sigset_t *which, siginfo_t *info,
+static int do_sigtimedwait(const sigset_t *which, siginfo_t *info,
const struct timespec *ts)
{
ktime_t *to = NULL, timeout = KTIME_MAX;
@@ -2865,6 +2911,40 @@ SYSCALL_DEFINE4(rt_sigtimedwait, const sigset_t __user *, uthese,
return ret;
}
+#ifdef CONFIG_COMPAT
+COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait, compat_sigset_t __user *, uthese,
+ struct compat_siginfo __user *, uinfo,
+ struct compat_timespec __user *, uts, compat_size_t, sigsetsize)
+{
+ compat_sigset_t s32;
+ sigset_t s;
+ struct timespec t;
+ siginfo_t info;
+ long ret;
+
+ if (sigsetsize != sizeof(sigset_t))
+ return -EINVAL;
+
+ if (copy_from_user(&s32, uthese, sizeof(compat_sigset_t)))
+ return -EFAULT;
+ sigset_from_compat(&s, &s32);
+
+ if (uts) {
+ if (compat_get_timespec(&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;
+}
+#endif
+
/**
* sys_kill - send a signal to a process
* @pid: the PID of the process
@@ -3121,78 +3201,68 @@ int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact)
}
static int
-do_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, unsigned long sp)
+do_sigaltstack (const stack_t *ss, stack_t *oss, unsigned long sp)
{
- stack_t oss;
- int error;
+ struct task_struct *t = current;
- oss.ss_sp = (void __user *) current->sas_ss_sp;
- oss.ss_size = current->sas_ss_size;
- oss.ss_flags = sas_ss_flags(sp) |
- (current->sas_ss_flags & SS_FLAG_BITS);
+ if (oss) {
+ memset(oss, 0, sizeof(stack_t));
+ oss->ss_sp = (void __user *) t->sas_ss_sp;
+ oss->ss_size = t->sas_ss_size;
+ oss->ss_flags = sas_ss_flags(sp) |
+ (current->sas_ss_flags & SS_FLAG_BITS);
+ }
- if (uss) {
- void __user *ss_sp;
- size_t ss_size;
- unsigned ss_flags;
+ if (ss) {
+ void __user *ss_sp = ss->ss_sp;
+ size_t ss_size = ss->ss_size;
+ unsigned ss_flags = ss->ss_flags;
int ss_mode;
- error = -EFAULT;
- if (!access_ok(VERIFY_READ, uss, sizeof(*uss)))
- goto out;
- error = __get_user(ss_sp, &uss->ss_sp) |
- __get_user(ss_flags, &uss->ss_flags) |
- __get_user(ss_size, &uss->ss_size);
- if (error)
- goto out;
-
- error = -EPERM;
- if (on_sig_stack(sp))
- goto out;
+ if (unlikely(on_sig_stack(sp)))
+ return -EPERM;
ss_mode = ss_flags & ~SS_FLAG_BITS;
- error = -EINVAL;
- if (ss_mode != SS_DISABLE && ss_mode != SS_ONSTACK &&
- ss_mode != 0)
- goto out;
+ if (unlikely(ss_mode != SS_DISABLE && ss_mode != SS_ONSTACK &&
+ ss_mode != 0))
+ return -EINVAL;
if (ss_mode == SS_DISABLE) {
ss_size = 0;
ss_sp = NULL;
} else {
- error = -ENOMEM;
- if (ss_size < MINSIGSTKSZ)
- goto out;
+ if (unlikely(ss_size < MINSIGSTKSZ))
+ return -ENOMEM;
}
- current->sas_ss_sp = (unsigned long) ss_sp;
- current->sas_ss_size = ss_size;
- current->sas_ss_flags = ss_flags;
+ t->sas_ss_sp = (unsigned long) ss_sp;
+ t->sas_ss_size = ss_size;
+ t->sas_ss_flags = ss_flags;
}
-
- error = 0;
- if (uoss) {
- error = -EFAULT;
- if (!access_ok(VERIFY_WRITE, uoss, sizeof(*uoss)))
- goto out;
- error = __put_user(oss.ss_sp, &uoss->ss_sp) |
- __put_user(oss.ss_size, &uoss->ss_size) |
- __put_user(oss.ss_flags, &uoss->ss_flags);
- }
-
-out:
- return error;
+ return 0;
}
+
SYSCALL_DEFINE2(sigaltstack,const stack_t __user *,uss, stack_t __user *,uoss)
{
- return do_sigaltstack(uss, uoss, current_user_stack_pointer());
+ stack_t new, old;
+ int err;
+ 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());
+ if (!err && uoss && copy_to_user(uoss, &old, sizeof(stack_t)))
+ err = -EFAULT;
+ return err;
}
int restore_altstack(const stack_t __user *uss)
{
- int err = do_sigaltstack(uss, NULL, current_user_stack_pointer());
+ stack_t new;
+ if (copy_from_user(&new, uss, sizeof(stack_t)))
+ return -EFAULT;
+ (void)do_sigaltstack(&new, NULL, current_user_stack_pointer());
/* squash all but EFAULT for now */
- return err == -EFAULT ? err : 0;
+ return 0;
}
int __save_altstack(stack_t __user *uss, unsigned long sp)
@@ -3215,29 +3285,24 @@ COMPAT_SYSCALL_DEFINE2(sigaltstack,
{
stack_t uss, uoss;
int ret;
- mm_segment_t seg;
if (uss_ptr) {
compat_stack_t uss32;
-
- memset(&uss, 0, sizeof(stack_t));
if (copy_from_user(&uss32, uss_ptr, sizeof(compat_stack_t)))
return -EFAULT;
uss.ss_sp = compat_ptr(uss32.ss_sp);
uss.ss_flags = uss32.ss_flags;
uss.ss_size = uss32.ss_size;
}
- seg = get_fs();
- set_fs(KERNEL_DS);
- ret = do_sigaltstack((stack_t __force __user *) (uss_ptr ? &uss : NULL),
- (stack_t __force __user *) &uoss,
+ ret = do_sigaltstack(uss_ptr ? &uss : NULL, &uoss,
compat_user_stack_pointer());
- set_fs(seg);
if (ret >= 0 && uoss_ptr) {
- if (!access_ok(VERIFY_WRITE, uoss_ptr, sizeof(compat_stack_t)) ||
- __put_user(ptr_to_compat(uoss.ss_sp), &uoss_ptr->ss_sp) ||
- __put_user(uoss.ss_flags, &uoss_ptr->ss_flags) ||
- __put_user(uoss.ss_size, &uoss_ptr->ss_size))
+ compat_stack_t old;
+ memset(&old, 0, sizeof(old));
+ old.ss_sp = ptr_to_compat(uoss.ss_sp);
+ old.ss_flags = uoss.ss_flags;
+ old.ss_size = uoss.ss_size;
+ if (copy_to_user(uoss_ptr, &old, sizeof(compat_stack_t)))
ret = -EFAULT;
}
return ret;
@@ -3277,6 +3342,21 @@ SYSCALL_DEFINE1(sigpending, old_sigset_t __user *, set)
return sys_rt_sigpending((sigset_t __user *)set, sizeof(old_sigset_t));
}
+#ifdef CONFIG_COMPAT
+COMPAT_SYSCALL_DEFINE1(sigpending, compat_old_sigset_t __user *, set32)
+{
+#ifdef __BIG_ENDIAN
+ sigset_t set;
+ int err = do_sigpending(&set, sizeof(set.sig[0]));
+ if (!err)
+ err = put_user(set.sig[0], set32);
+ return err;
+#else
+ return sys_rt_sigpending((sigset_t __user *)set32, sizeof(*set32));
+#endif
+}
+#endif
+
#endif
#ifdef __ARCH_WANT_SYS_SIGPROCMASK
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2025-05-11 01:37:52 +0200