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

Pull siginfo updates from Eric Biederman:
 "This set of changes close the known issues with setting si_code to an
  invalid value, and with not fully initializing struct siginfo. There
  remains work to do on nds32, arc, unicore32, powerpc, arm, arm64, ia64
  and x86 to get the code that generates siginfo into a simpler and more
  maintainable state. Most of that work involves refactoring the signal
  handling code and thus careful code review.

  Also not included is the work to shrink the in kernel version of
  struct siginfo. That depends on getting the number of places that
  directly manipulate struct siginfo under control, as it requires the
  introduction of struct kernel_siginfo for the in kernel things.

  Overall this set of changes looks like it is making good progress, and
  with a little luck I will be wrapping up the siginfo work next
  development cycle"

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (46 commits)
  signal/sh: Stop gcc warning about an impossible case in do_divide_error
  signal/mips: Report FPE_FLTUNK for undiagnosed floating point exceptions
  signal/um: More carefully relay signals in relay_signal.
  signal: Extend siginfo_layout with SIL_FAULT_{MCEERR|BNDERR|PKUERR}
  signal: Remove unncessary #ifdef SEGV_PKUERR in 32bit compat code
  signal/signalfd: Add support for SIGSYS
  signal/signalfd: Remove __put_user from signalfd_copyinfo
  signal/xtensa: Use force_sig_fault where appropriate
  signal/xtensa: Consistenly use SIGBUS in do_unaligned_user
  signal/um: Use force_sig_fault where appropriate
  signal/sparc: Use force_sig_fault where appropriate
  signal/sparc: Use send_sig_fault where appropriate
  signal/sh: Use force_sig_fault where appropriate
  signal/s390: Use force_sig_fault where appropriate
  signal/riscv: Replace do_trap_siginfo with force_sig_fault
  signal/riscv: Use force_sig_fault where appropriate
  signal/parisc: Use force_sig_fault where appropriate
  signal/parisc: Use force_sig_mceerr where appropriate
  signal/openrisc: Use force_sig_fault where appropriate
  signal/nios2: Use force_sig_fault where appropriate
  ...

2 files changed, 25 insertions, 50 deletions

diff --git a/arch/um/kernel/ptrace.c b/arch/um/kernel/ptrace.c
index bc2a516c190f..1a1d88a4d940 100644
--- a/arch/um/kernel/ptrace.c
+++ b/arch/um/kernel/ptrace.c
@@ -115,17 +115,10 @@ long arch_ptrace(struct task_struct *child, long request,
 static void send_sigtrap(struct task_struct *tsk, struct uml_pt_regs *regs,
 		  int error_code)
 {
-	struct siginfo info;
-
-	memset(&info, 0, sizeof(info));
-	info.si_signo = SIGTRAP;
-	info.si_code = TRAP_BRKPT;
-
-	/* User-mode eip? */
-	info.si_addr = UPT_IS_USER(regs) ? (void __user *) UPT_IP(regs) : NULL;
-
 	/* Send us the fake SIGTRAP */
-	force_sig_info(SIGTRAP, &info, tsk);
+	force_sig_fault(SIGTRAP, TRAP_BRKPT,
+			/* User-mode eip? */
+			UPT_IS_USER(regs) ? (void __user *) UPT_IP(regs) : NULL, tsk);
 }
 
 /*
diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index b2b02df9896e..ec9a42c14c56 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -162,13 +162,9 @@ static void show_segv_info(struct uml_pt_regs *regs)
 
 static void bad_segv(struct faultinfo fi, unsigned long ip)
 {
-	struct siginfo si;
-
-	si.si_signo = SIGSEGV;
-	si.si_code = SEGV_ACCERR;
-	si.si_addr = (void __user *) FAULT_ADDRESS(fi);
 	current->thread.arch.faultinfo = fi;
-	force_sig_info(SIGSEGV, &si, current);
+	force_sig_fault(SIGSEGV, SEGV_ACCERR, (void __user *) FAULT_ADDRESS(fi),
+			current);
 }
 
 void fatal_sigsegv(void)
@@ -214,8 +210,8 @@ void segv_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
 unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
 		   struct uml_pt_regs *regs)
 {
-	struct siginfo si;
 	jmp_buf *catcher;
+	int si_code;
 	int err;
 	int is_write = FAULT_WRITE(fi);
 	unsigned long address = FAULT_ADDRESS(fi);
@@ -239,7 +235,7 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
 
 	if (SEGV_IS_FIXABLE(&fi))
 		err = handle_page_fault(address, ip, is_write, is_user,
-					&si.si_code);
+					&si_code);
 	else {
 		err = -EFAULT;
 		/*
@@ -271,18 +267,14 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
 	show_segv_info(regs);
 
 	if (err == -EACCES) {
-		si.si_signo = SIGBUS;
-		si.si_errno = 0;
-		si.si_code = BUS_ADRERR;
-		si.si_addr = (void __user *)address;
 		current->thread.arch.faultinfo = fi;
-		force_sig_info(SIGBUS, &si, current);
+		force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address,
+				current);
 	} else {
 		BUG_ON(err != -EFAULT);
-		si.si_signo = SIGSEGV;
-		si.si_addr = (void __user *) address;
 		current->thread.arch.faultinfo = fi;
-		force_sig_info(SIGSEGV, &si, current);
+		force_sig_fault(SIGSEGV, si_code, (void __user *) address,
+				current);
 	}
 
 out:
@@ -294,9 +286,7 @@ out:
 
 void relay_signal(int sig, struct siginfo *si, struct uml_pt_regs *regs)
 {
-	struct faultinfo *fi;
-	struct siginfo clean_si;
-
+	int code, err;
 	if (!UPT_IS_USER(regs)) {
 		if (sig == SIGBUS)
 			printk(KERN_ERR "Bus error - the host /dev/shm or /tmp "
@@ -306,29 +296,21 @@ void relay_signal(int sig, struct siginfo *si, struct uml_pt_regs *regs)
 
 	arch_examine_signal(sig, regs);
 
-	clear_siginfo(&clean_si);
-	clean_si.si_signo = si->si_signo;
-	clean_si.si_errno = si->si_errno;
-	clean_si.si_code = si->si_code;
-	switch (sig) {
-	case SIGILL:
-	case SIGFPE:
-	case SIGSEGV:
-	case SIGBUS:
-	case SIGTRAP:
-		fi = UPT_FAULTINFO(regs);
-		clean_si.si_addr = (void __user *) FAULT_ADDRESS(*fi);
+	/* Is the signal layout for the signal known?
+	 * Signal data must be scrubbed to prevent information leaks.
+	 */
+	code = si->si_code;
+	err = si->si_errno;
+	if ((err == 0) && (siginfo_layout(sig, code) == SIL_FAULT)) {
+		struct faultinfo *fi = UPT_FAULTINFO(regs);
 		current->thread.arch.faultinfo = *fi;
-#ifdef __ARCH_SI_TRAPNO
-		clean_si.si_trapno = si->si_trapno;
-#endif
-		break;
-	default:
-		printk(KERN_ERR "Attempted to relay unknown signal %d (si_code = %d)\n",
-			sig, si->si_code);
+		force_sig_fault(sig, code, (void __user *)FAULT_ADDRESS(*fi),
+				current);
+	} else {
+		printk(KERN_ERR "Attempted to relay unknown signal %d (si_code = %d) with errno %d\n",
+		       sig, code, err);
+		force_sig(sig, current);
 	}
-
-	force_sig_info(sig, &clean_si, current);
 }
 
 void bus_handler(int sig, struct siginfo *si, struct uml_pt_regs *regs)