Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

Pull siginfo cleanups from Eric Biederman:
 "Long ago when 2.4 was just a testing release copy_siginfo_to_user was
  made to copy individual fields to userspace, possibly for efficiency
  and to ensure initialized values were not copied to userspace.

  Unfortunately the design was complex, it's assumptions unstated, and
  humans are fallible and so while it worked much of the time that
  design failed to ensure unitialized memory is not copied to userspace.

  This set of changes is part of a new design to clean up siginfo and
  simplify things, and hopefully make the siginfo handling robust enough
  that a simple inspection of the code can be made to ensure we don't
  copy any unitializied fields to userspace.

  The design is to unify struct siginfo and struct compat_siginfo into a
  single definition that is shared between all architectures so that
  anyone adding to the set of information shared with struct siginfo can
  see the whole picture. Hopefully ensuring all future si_code
  assignments are arch independent.

  The design is to unify copy_siginfo_to_user32 and
  copy_siginfo_from_user32 so that those function are complete and cope
  with all of the different cases documented in signinfo_layout. I don't
  think there was a single implementation of either of those functions
  that was complete and correct before my changes unified them.

  The design is to introduce a series of helpers including
  force_siginfo_fault that take the values that are needed in struct
  siginfo and build the siginfo structure for their callers. Ensuring
  struct siginfo is built correctly.

  The remaining work for 4.17 (unless someone thinks it is post -rc1
  material) is to push usage of those helpers down into the
  architectures so that architecture specific code will not need to deal
  with the fiddly work of intializing struct siginfo, and then when
  struct siginfo is guaranteed to be fully initialized change copy
  siginfo_to_user into a simple wrapper around copy_to_user.

  Further there is work in progress on the issues that have been
  documented requires arch specific knowledge to sort out.

  The changes below fix or at least document all of the issues that have
  been found with siginfo generation. Then proceed to unify struct
  siginfo the 32 bit helpers that copy siginfo to and from userspace,
  and generally clean up anything that is not arch specific with regards
  to siginfo generation.

  It is a lot but with the unification you can of siginfo you can
  already see the code reduction in the kernel"

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (45 commits)
  signal/memory-failure: Use force_sig_mceerr and send_sig_mceerr
  mm/memory_failure: Remove unused trapno from memory_failure
  signal/ptrace: Add force_sig_ptrace_errno_trap and use it where needed
  signal/powerpc: Remove unnecessary signal_code parameter of do_send_trap
  signal: Helpers for faults with specialized siginfo layouts
  signal: Add send_sig_fault and force_sig_fault
  signal: Replace memset(info,...) with clear_siginfo for clarity
  signal: Don't use structure initializers for struct siginfo
  signal/arm64: Better isolate the COMPAT_TASK portion of ptrace_hbptriggered
  ptrace: Use copy_siginfo in setsiginfo and getsiginfo
  signal: Unify and correct copy_siginfo_to_user32
  signal: Remove the code to clear siginfo before calling copy_siginfo_from_user32
  signal: Unify and correct copy_siginfo_from_user32
  signal/blackfin: Remove pointless UID16_SIGINFO_COMPAT_NEEDED
  signal/blackfin: Move the blackfin specific si_codes to asm-generic/siginfo.h
  signal/tile: Move the tile specific si_codes to asm-generic/siginfo.h
  signal/frv: Move the frv specific si_codes to asm-generic/siginfo.h
  signal/ia64: Move the ia64 specific si_codes to asm-generic/siginfo.h
  signal/powerpc: Remove redefinition of NSIGTRAP on powerpc
  signal: Move addr_lsb into the _sigfault union for clarity
  ...

6 files changed, 337 insertions, 34 deletions

diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index c8146d53ca67..dbb0781a0533 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -2441,7 +2441,6 @@ static int kdb_kill(int argc, const char **argv)
 	long sig, pid;
 	char *endp;
 	struct task_struct *p;
-	struct siginfo info;
 
 	if (argc != 2)
 		return KDB_ARGCOUNT;
@@ -2449,7 +2448,7 @@ static int kdb_kill(int argc, const char **argv)
 	sig = simple_strtol(argv[1], &endp, 0);
 	if (*endp)
 		return KDB_BADINT;
-	if (sig >= 0) {
+	if ((sig >= 0) || !valid_signal(-sig)) {
 		kdb_printf("Invalid signal parameter.<-signal>\n");
 		return 0;
 	}
@@ -2470,12 +2469,7 @@ static int kdb_kill(int argc, const char **argv)
 		return 0;
 	}
 	p = p->group_leader;
-	info.si_signo = sig;
-	info.si_errno = 0;
-	info.si_code = SI_USER;
-	info.si_pid = pid;  /* same capabilities as process being signalled */
-	info.si_uid = 0;    /* kdb has root authority */
-	kdb_send_sig_info(p, &info);
+	kdb_send_sig(p, sig);
 	return 0;
 }
 
diff --git a/kernel/debug/kdb/kdb_private.h b/kernel/debug/kdb/kdb_private.h
index fc224fbcf954..1e5a502ba4a7 100644
--- a/kernel/debug/kdb/kdb_private.h
+++ b/kernel/debug/kdb/kdb_private.h
@@ -208,7 +208,7 @@ extern unsigned long kdb_task_state(const struct task_struct *p,
 extern void kdb_ps_suppressed(void);
 extern void kdb_ps1(const struct task_struct *p);
 extern void kdb_print_nameval(const char *name, unsigned long val);
-extern void kdb_send_sig_info(struct task_struct *p, struct siginfo *info);
+extern void kdb_send_sig(struct task_struct *p, int sig);
 extern void kdb_meminfo_proc_show(void);
 extern char *kdb_getstr(char *, size_t, const char *);
 extern void kdb_gdb_state_pass(char *buf);
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 84b1367935e4..f3c82e26b995 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -659,7 +659,7 @@ static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info)
 	if (lock_task_sighand(child, &flags)) {
 		error = -EINVAL;
 		if (likely(child->last_siginfo != NULL)) {
-			*info = *child->last_siginfo;
+			copy_siginfo(info, child->last_siginfo);
 			error = 0;
 		}
 		unlock_task_sighand(child, &flags);
@@ -675,7 +675,7 @@ static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info)
 	if (lock_task_sighand(child, &flags)) {
 		error = -EINVAL;
 		if (likely(child->last_siginfo != NULL)) {
-			*child->last_siginfo = *info;
+			copy_siginfo(child->last_siginfo, info);
 			error = 0;
 		}
 		unlock_task_sighand(child, &flags);
@@ -1226,7 +1226,6 @@ int compat_ptrace_request(struct task_struct *child, compat_long_t request,
 		break;
 
 	case PTRACE_SETSIGINFO:
-		memset(&siginfo, 0, sizeof siginfo);
 		if (copy_siginfo_from_user32(
 			    &siginfo, (struct compat_siginfo __user *) datap))
 			ret = -EFAULT;
diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index 5f0dfb2abb8d..3153c9ea51bf 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -515,7 +515,7 @@ void put_seccomp_filter(struct task_struct *tsk)
 
 static void seccomp_init_siginfo(siginfo_t *info, int syscall, int reason)
 {
-	memset(info, 0, sizeof(*info));
+	clear_siginfo(info);
 	info->si_signo = SIGSYS;
 	info->si_code = SYS_SECCOMP;
 	info->si_call_addr = (void __user *)KSTK_EIP(current);
diff --git a/kernel/signal.c b/kernel/signal.c
index 9558664bd9ec..e549174c0831 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -549,6 +549,7 @@ still_pending:
 		 * a fast-pathed signal or we must have been
 		 * out of queue space.  So zero out the info.
 		 */
+		clear_siginfo(info);
 		info->si_signo = sig;
 		info->si_errno = 0;
 		info->si_code = SI_USER;
@@ -642,6 +643,9 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
 		spin_unlock(&tsk->sighand->siglock);
 		posixtimer_rearm(info);
 		spin_lock(&tsk->sighand->siglock);
+
+		/* Don't expose the si_sys_private value to userspace */
+		info->si_sys_private = 0;
 	}
 #endif
 	return signr;
@@ -1043,6 +1047,7 @@ static int __send_signal(int sig, struct siginfo *info, struct task_struct *t,
 		list_add_tail(&q->list, &pending->list);
 		switch ((unsigned long) info) {
 		case (unsigned long) SEND_SIG_NOINFO:
+			clear_siginfo(&q->info);
 			q->info.si_signo = sig;
 			q->info.si_errno = 0;
 			q->info.si_code = SI_USER;
@@ -1051,6 +1056,7 @@ static int __send_signal(int sig, struct siginfo *info, struct task_struct *t,
 			q->info.si_uid = from_kuid_munged(current_user_ns(), current_uid());
 			break;
 		case (unsigned long) SEND_SIG_PRIV:
+			clear_siginfo(&q->info);
 			q->info.si_signo = sig;
 			q->info.si_errno = 0;
 			q->info.si_code = SI_KERNEL;
@@ -1485,6 +1491,129 @@ force_sigsegv(int sig, struct task_struct *p)
 	return 0;
 }
 
+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)
+	, struct task_struct *t)
+{
+	struct siginfo info;
+
+	clear_siginfo(&info);
+	info.si_signo = sig;
+	info.si_errno = 0;
+	info.si_code  = code;
+	info.si_addr  = addr;
+#ifdef __ARCH_SI_TRAPNO
+	info.si_trapno = trapno;
+#endif
+#ifdef __ia64__
+	info.si_imm = imm;
+	info.si_flags = flags;
+	info.si_isr = isr;
+#endif
+	return force_sig_info(info.si_signo, &info, t);
+}
+
+int send_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)
+	, struct task_struct *t)
+{
+	struct siginfo info;
+
+	clear_siginfo(&info);
+	info.si_signo = sig;
+	info.si_errno = 0;
+	info.si_code  = code;
+	info.si_addr  = addr;
+#ifdef __ARCH_SI_TRAPNO
+	info.si_trapno = trapno;
+#endif
+#ifdef __ia64__
+	info.si_imm = imm;
+	info.si_flags = flags;
+	info.si_isr = isr;
+#endif
+	return send_sig_info(info.si_signo, &info, t);
+}
+
+#if defined(BUS_MCEERR_AO) && defined(BUS_MCEERR_AR)
+int force_sig_mceerr(int code, void __user *addr, short lsb, struct task_struct *t)
+{
+	struct siginfo info;
+
+	WARN_ON((code != BUS_MCEERR_AO) && (code != BUS_MCEERR_AR));
+	clear_siginfo(&info);
+	info.si_signo = SIGBUS;
+	info.si_errno = 0;
+	info.si_code = code;
+	info.si_addr = addr;
+	info.si_addr_lsb = lsb;
+	return force_sig_info(info.si_signo, &info, t);
+}
+
+int send_sig_mceerr(int code, void __user *addr, short lsb, struct task_struct *t)
+{
+	struct siginfo info;
+
+	WARN_ON((code != BUS_MCEERR_AO) && (code != BUS_MCEERR_AR));
+	clear_siginfo(&info);
+	info.si_signo = SIGBUS;
+	info.si_errno = 0;
+	info.si_code = code;
+	info.si_addr = addr;
+	info.si_addr_lsb = lsb;
+	return send_sig_info(info.si_signo, &info, t);
+}
+EXPORT_SYMBOL(send_sig_mceerr);
+#endif
+
+#ifdef SEGV_BNDERR
+int force_sig_bnderr(void __user *addr, void __user *lower, void __user *upper)
+{
+	struct siginfo info;
+
+	clear_siginfo(&info);
+	info.si_signo = SIGSEGV;
+	info.si_errno = 0;
+	info.si_code  = SEGV_BNDERR;
+	info.si_addr  = addr;
+	info.si_lower = lower;
+	info.si_upper = upper;
+	return force_sig_info(info.si_signo, &info, current);
+}
+#endif
+
+#ifdef SEGV_PKUERR
+int force_sig_pkuerr(void __user *addr, u32 pkey)
+{
+	struct siginfo info;
+
+	clear_siginfo(&info);
+	info.si_signo = SIGSEGV;
+	info.si_errno = 0;
+	info.si_code  = SEGV_PKUERR;
+	info.si_addr  = addr;
+	info.si_pkey  = pkey;
+	return force_sig_info(info.si_signo, &info, current);
+}
+#endif
+
+/* For the crazy architectures that include trap information in
+ * the errno field, instead of an actual errno value.
+ */
+int force_sig_ptrace_errno_trap(int errno, void __user *addr)
+{
+	struct 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);
+}
+
 int kill_pgrp(struct pid *pid, int sig, int priv)
 {
 	int ret;
@@ -1623,6 +1752,7 @@ bool do_notify_parent(struct task_struct *tsk, int sig)
 			sig = SIGCHLD;
 	}
 
+	clear_siginfo(&info);
 	info.si_signo = sig;
 	info.si_errno = 0;
 	/*
@@ -1717,6 +1847,7 @@ static void do_notify_parent_cldstop(struct task_struct *tsk,
 		parent = tsk->real_parent;
 	}
 
+	clear_siginfo(&info);
 	info.si_signo = SIGCHLD;
 	info.si_errno = 0;
 	/*
@@ -1929,7 +2060,7 @@ static void ptrace_do_notify(int signr, int exit_code, int why)
 {
 	siginfo_t info;
 
-	memset(&info, 0, sizeof info);
+	clear_siginfo(&info);
 	info.si_signo = signr;
 	info.si_code = exit_code;
 	info.si_pid = task_pid_vnr(current);
@@ -2136,6 +2267,7 @@ static int ptrace_signal(int signr, siginfo_t *info)
 	 * have updated *info via PTRACE_SETSIGINFO.
 	 */
 	if (signr != info->si_signo) {
+		clear_siginfo(info);
 		info->si_signo = signr;
 		info->si_errno = 0;
 		info->si_code = SI_USER;
@@ -2688,9 +2820,7 @@ enum siginfo_layout siginfo_layout(int sig, int si_code)
 #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;
@@ -2712,12 +2842,14 @@ enum siginfo_layout siginfo_layout(int sig, int si_code)
 		if ((sig == SIGFPE) && (si_code == FPE_FIXME))
 			layout = SIL_FAULT;
 #endif
+#ifdef BUS_FIXME
+		if ((sig == SIGBUS) && (si_code == BUS_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)
 {
 	int err;
@@ -2756,13 +2888,21 @@ int copy_siginfo_to_user(siginfo_t __user *to, const siginfo_t *from)
 #ifdef __ARCH_SI_TRAPNO
 		err |= __put_user(from->si_trapno, &to->si_trapno);
 #endif
-#ifdef BUS_MCEERR_AO
+#ifdef __ia64__
+		err |= __put_user(from->si_imm, &to->si_imm);
+		err |= __put_user(from->si_flags, &to->si_flags);
+		err |= __put_user(from->si_isr, &to->si_isr);
+#endif
 		/*
 		 * Other callers might not initialize the si_lsb field,
 		 * so check explicitly for the right codes here.
 		 */
-		if (from->si_signo == SIGBUS &&
-		    (from->si_code == BUS_MCEERR_AR || from->si_code == BUS_MCEERR_AO))
+#ifdef BUS_MCEERR_AR
+		if (from->si_signo == SIGBUS && from->si_code == BUS_MCEERR_AR)
+			err |= __put_user(from->si_addr_lsb, &to->si_addr_lsb);
+#endif
+#ifdef BUS_MCEERR_AO
+		if (from->si_signo == SIGBUS && from->si_code == BUS_MCEERR_AO)
 			err |= __put_user(from->si_addr_lsb, &to->si_addr_lsb);
 #endif
 #ifdef SEGV_BNDERR
@@ -2788,18 +2928,185 @@ int copy_siginfo_to_user(siginfo_t __user *to, const siginfo_t *from)
 		err |= __put_user(from->si_uid, &to->si_uid);
 		err |= __put_user(from->si_ptr, &to->si_ptr);
 		break;
-#ifdef __ARCH_SIGSYS
 	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
 	}
 	return err;
 }
 
+#ifdef CONFIG_COMPAT
+int copy_siginfo_to_user32(struct compat_siginfo __user *to,
+			   const struct 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)
+#endif
+{
+	struct compat_siginfo new;
+	memset(&new, 0, sizeof(new));
+
+	new.si_signo = from->si_signo;
+	new.si_errno = from->si_errno;
+	new.si_code  = from->si_code;
+	switch(siginfo_layout(from->si_signo, from->si_code)) {
+	case SIL_KILL:
+		new.si_pid = from->si_pid;
+		new.si_uid = from->si_uid;
+		break;
+	case SIL_TIMER:
+		new.si_tid     = from->si_tid;
+		new.si_overrun = from->si_overrun;
+		new.si_int     = from->si_int;
+		break;
+	case SIL_POLL:
+		new.si_band = from->si_band;
+		new.si_fd   = from->si_fd;
+		break;
+	case SIL_FAULT:
+		new.si_addr = ptr_to_compat(from->si_addr);
+#ifdef __ARCH_SI_TRAPNO
+		new.si_trapno = from->si_trapno;
+#endif
+#ifdef BUS_MCEERR_AR
+		if ((from->si_signo == SIGBUS) && (from->si_code == BUS_MCEERR_AR))
+			new.si_addr_lsb = from->si_addr_lsb;
+#endif
+#ifdef BUS_MCEERR_AO
+		if ((from->si_signo == SIGBUS) && (from->si_code == BUS_MCEERR_AO))
+			new.si_addr_lsb = from->si_addr_lsb;
+#endif
+#ifdef SEGV_BNDERR
+		if ((from->si_signo == SIGSEGV) &&
+		    (from->si_code == SEGV_BNDERR)) {
+			new.si_lower = ptr_to_compat(from->si_lower);
+			new.si_upper = ptr_to_compat(from->si_upper);
+		}
+#endif
+#ifdef SEGV_PKUERR
+		if ((from->si_signo == SIGSEGV) &&
+		    (from->si_code == SEGV_PKUERR))
+			new.si_pkey = from->si_pkey;
+#endif
+
+		break;
+	case SIL_CHLD:
+		new.si_pid    = from->si_pid;
+		new.si_uid    = from->si_uid;
+		new.si_status = from->si_status;
+#ifdef CONFIG_X86_X32_ABI
+		if (x32_ABI) {
+			new._sifields._sigchld_x32._utime = from->si_utime;
+			new._sifields._sigchld_x32._stime = from->si_stime;
+		} else
+#endif
+		{
+			new.si_utime = from->si_utime;
+			new.si_stime = from->si_stime;
+		}
+		break;
+	case SIL_RT:
+		new.si_pid = from->si_pid;
+		new.si_uid = from->si_uid;
+		new.si_int = from->si_int;
+		break;
+	case SIL_SYS:
+		new.si_call_addr = ptr_to_compat(from->si_call_addr);
+		new.si_syscall   = from->si_syscall;
+		new.si_arch      = from->si_arch;
+		break;
+	}
+
+	if (copy_to_user(to, &new, sizeof(struct compat_siginfo)))
+		return -EFAULT;
+
+	return 0;
+}
+
+int copy_siginfo_from_user32(struct siginfo *to,
+			     const struct compat_siginfo __user *ufrom)
+{
+	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)) {
+	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
+#ifdef BUS_MCEERR_AR
+		if ((from.si_signo == SIGBUS) && (from.si_code == BUS_MCEERR_AR))
+			to->si_addr_lsb = from.si_addr_lsb;
+#endif
+#ifdef BUS_MCEER_AO
+		if ((from.si_signo == SIGBUS) && (from.si_code == BUS_MCEERR_AO))
+			to->si_addr_lsb = from.si_addr_lsb;
+#endif
+#ifdef SEGV_BNDERR
+		if ((from.si_signo == SIGSEGV) && (from.si_code == SEGV_BNDERR)) {
+			to->si_lower = compat_ptr(from.si_lower);
+			to->si_upper = compat_ptr(from.si_upper);
+		}
+#endif
+#ifdef SEGV_PKUERR
+		if ((from.si_signo == SIGSEGV) && (from.si_code == SEGV_PKUERR))
+			to->si_pkey = from.si_pkey;
+#endif
+		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;
+}
+#endif /* CONFIG_COMPAT */
 
 /**
  *  do_sigtimedwait - wait for queued signals specified in @which
@@ -2937,6 +3244,7 @@ SYSCALL_DEFINE2(kill, pid_t, pid, int, sig)
 {
 	struct siginfo info;
 
+	clear_siginfo(&info);
 	info.si_signo = sig;
 	info.si_errno = 0;
 	info.si_code = SI_USER;
@@ -2978,8 +3286,9 @@ 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 siginfo info;
 
+	clear_siginfo(&info);
 	info.si_signo = sig;
 	info.si_errno = 0;
 	info.si_code = SI_TKILL;
@@ -3060,7 +3369,7 @@ COMPAT_SYSCALL_DEFINE3(rt_sigqueueinfo,
 			int, sig,
 			struct compat_siginfo __user *, uinfo)
 {
-	siginfo_t info = {};
+	siginfo_t info;
 	int ret = copy_siginfo_from_user32(&info, uinfo);
 	if (unlikely(ret))
 		return ret;
@@ -3104,7 +3413,7 @@ COMPAT_SYSCALL_DEFINE4(rt_tgsigqueueinfo,
 			int, sig,
 			struct compat_siginfo __user *, uinfo)
 {
-	siginfo_t info = {};
+	siginfo_t info;
 
 	if (copy_siginfo_from_user32(&info, uinfo))
 		return -EFAULT;
@@ -3677,6 +3986,7 @@ 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);
 
 	sigqueue_cachep = KMEM_CACHE(sigqueue, SLAB_PANIC);
 }
@@ -3684,26 +3994,25 @@ void __init signals_init(void)
 #ifdef CONFIG_KGDB_KDB
 #include <linux/kdb.h>
 /*
- * kdb_send_sig_info - Allows kdb to send signals without exposing
+ * kdb_send_sig - Allows kdb to send signals without exposing
  * signal internals.  This function checks if the required locks are
  * available before calling the main signal code, to avoid kdb
  * deadlocks.
  */
-void
-kdb_send_sig_info(struct task_struct *t, struct siginfo *info)
+void kdb_send_sig(struct task_struct *t, int sig)
 {
 	static struct task_struct *kdb_prev_t;
-	int sig, new_t;
+	int new_t, ret;
 	if (!spin_trylock(&t->sighand->siglock)) {
 		kdb_printf("Can't do kill command now.\n"
 			   "The sigmask lock is held somewhere else in "
 			   "kernel, try again later\n");
 		return;
 	}
-	spin_unlock(&t->sighand->siglock);
 	new_t = kdb_prev_t != t;
 	kdb_prev_t = t;
 	if (t->state != TASK_RUNNING && new_t) {
+		spin_unlock(&t->sighand->siglock);
 		kdb_printf("Process is not RUNNING, sending a signal from "
 			   "kdb risks deadlock\n"
 			   "on the run queue locks. "
@@ -3712,8 +4021,9 @@ kdb_send_sig_info(struct task_struct *t, struct siginfo *info)
 			   "the deadlock.\n");
 		return;
 	}
-	sig = info->si_signo;
-	if (send_sig_info(sig, info, t))
+	ret = send_signal(sig, SEND_SIG_PRIV, t, false);
+	spin_unlock(&t->sighand->siglock);
+	if (ret)
 		kdb_printf("Fail to deliver Signal %d to process %d.\n",
 			   sig, t->pid);
 	else
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index ec999f32c840..75043046914e 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -462,7 +462,7 @@ static struct k_itimer * alloc_posix_timer(void)
 		kmem_cache_free(posix_timers_cache, tmr);
 		return NULL;
 	}
-	memset(&tmr->sigq->info, 0, sizeof(siginfo_t));
+	clear_siginfo(&tmr->sigq->info);
 	return tmr;
 }