Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal

Pull signal handling cleanups from Al Viro:
 "This is the first pile; another one will come a bit later and will
  contain SYSCALL_DEFINE-related patches.

   - a bunch of signal-related syscalls (both native and compat)
     unified.

   - a bunch of compat syscalls switched to COMPAT_SYSCALL_DEFINE
     (fixing several potential problems with missing argument
     validation, while we are at it)

   - a lot of now-pointless wrappers killed

   - a couple of architectures (cris and hexagon) forgot to save
     altstack settings into sigframe, even though they used the
     (uninitialized) values in sigreturn; fixed.

   - microblaze fixes for delivery of multiple signals arriving at once

   - saner set of helpers for signal delivery introduced, several
     architectures switched to using those."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (143 commits)
  x86: convert to ksignal
  sparc: convert to ksignal
  arm: switch to struct ksignal * passing
  alpha: pass k_sigaction and siginfo_t using ksignal pointer
  burying unused conditionals
  make do_sigaltstack() static
  arm64: switch to generic old sigaction() (compat-only)
  arm64: switch to generic compat rt_sigaction()
  arm64: switch compat to generic old sigsuspend
  arm64: switch to generic compat rt_sigqueueinfo()
  arm64: switch to generic compat rt_sigpending()
  arm64: switch to generic compat rt_sigprocmask()
  arm64: switch to generic sigaltstack
  sparc: switch to generic old sigsuspend
  sparc: COMPAT_SYSCALL_DEFINE does all sign-extension as well as SYSCALL_DEFINE
  sparc: kill sign-extending wrappers for native syscalls
  kill sparc32_open()
  sparc: switch to use of generic old sigaction
  sparc: switch sys_compat_rt_sigaction() to COMPAT_SYSCALL_DEFINE
  mips: switch to generic sys_fork() and sys_clone()
  ...

4 files changed, 54 insertions, 78 deletions

diff --git a/arch/microblaze/kernel/entry-nommu.S b/arch/microblaze/kernel/entry-nommu.S
index 70da83a4967..7e394fc2c43 100644
--- a/arch/microblaze/kernel/entry-nommu.S
+++ b/arch/microblaze/kernel/entry-nommu.S
@@ -124,6 +124,7 @@ ret_from_intr:
 	lwi	r11, r1, PT_MODE
 	bneid	r11, no_intr_resched
 
+3:
 	lwi	r6, r31, TS_THREAD_INFO	/* get thread info */
 	lwi	r19, r6, TI_FLAGS	/* get flags in thread info */
 				/* do an extra work if any bits are set */
@@ -132,11 +133,13 @@ ret_from_intr:
 	beqi	r11, 1f
 	bralid	r15, schedule
 	nop
+	bri	3b
 1:	andi	r11, r19, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME
 	beqid	r11, no_intr_resched
 	addk	r5, r1, r0
 	bralid	r15, do_notify_resume
 	addk	r6, r0, r0
+	bri	3b
 
 no_intr_resched:
 	/* Disable interrupts, we are now committed to the state restore */
@@ -280,6 +283,7 @@ ENTRY(_user_exception)
 	/* Figure out which function to use for this system call. */
 	/* Note Microblaze barrel shift is optional, so don't rely on it */
 	add	r12, r12, r12			/* convert num -> ptr */
+	addik	r30, r0, 1			/* restarts allowed */
 	add	r12, r12, r12
 	lwi	r12, r12, sys_call_table	/* Get function pointer */
 	addik	r15, r0, ret_to_user-8		/* set return address */
@@ -369,6 +373,7 @@ ENTRY(_debug_exception)
 	bralid	r15, send_sig
 	add	r7, r0, r0			/* 3rd param zero */
 
+	addik	r30, r0, 1			/* restarts allowed ??? */
 	/* Restore r3/r4 to work around how ret_to_user works */
 	lwi	r3, r1, PT_R3
 	lwi	r4, r1, PT_R4
@@ -482,18 +487,26 @@ ENTRY(ret_from_kernel_thread)
 	addk	r3, r0, r0
 
 work_pending:
+	lwi	r11, r1, PT_MODE
+	bneid	r11, 2f
+3:
 	enable_irq
-
 	andi	r11, r19, _TIF_NEED_RESCHED
 	beqi	r11, 1f
 	bralid	r15, schedule
 	nop
+	bri	4f
 1:	andi	r11, r19, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME
 	beqi	r11, no_work_pending
-	addk	r5, r1, r0
+	addk	r5, r30, r0
 	bralid	r15, do_notify_resume
 	addik	r6, r0, 1
-	bri	no_work_pending
+	addk	r30, r0, r0	/* no restarts from now on */
+4:
+	disable_irq
+	lwi	r6, r31, TS_THREAD_INFO /* get thread info */
+	lwi	r19, r6, TI_FLAGS /* get flags in thread info */
+	bri	3b
 
 ENTRY(ret_to_user)
 	disable_irq
@@ -507,6 +520,7 @@ ENTRY(ret_to_user)
 no_work_pending:
 	disable_irq
 
+2:
 	/* save r31 */
 	swi	r31, r0, PER_CPU(CURRENT_SAVE)
 	/* save mode indicator */
@@ -559,6 +573,7 @@ no_work_pending:
 	nop
 
 sys_rt_sigreturn_wrapper:
+	addk	r30, r0, r0		/* no restarts for this one */
 	brid	sys_rt_sigreturn
 	addk	r5, r1, r0
 
diff --git a/arch/microblaze/kernel/entry.S b/arch/microblaze/kernel/entry.S
index c217367dfc7..0536bc021cc 100644
--- a/arch/microblaze/kernel/entry.S
+++ b/arch/microblaze/kernel/entry.S
@@ -354,6 +354,7 @@ C_ENTRY(_user_exception):
 	/* Note Microblaze barrel shift is optional, so don't rely on it */
 	add	r12, r12, r12;			/* convert num -> ptr */
 	add	r12, r12, r12;
+	addi	r30, r0, 1			/* restarts allowed */
 
 #ifdef DEBUG
 	/* Trac syscalls and stored them to syscall_debug_table */
@@ -401,26 +402,27 @@ C_ENTRY(ret_from_trap):
 	 * trigger rescheduling. */
 	/* get thread info from current task */
 	lwi	r11, CURRENT_TASK, TS_THREAD_INFO;
-	lwi	r11, r11, TI_FLAGS;		/* get flags in thread info */
-	andi	r11, r11, _TIF_NEED_RESCHED;
+	lwi	r19, r11, TI_FLAGS;		/* get flags in thread info */
+	andi	r11, r19, _TIF_NEED_RESCHED;
 	beqi	r11, 5f;
 
 	bralid	r15, schedule;	/* Call scheduler */
 	nop;				/* delay slot */
+	bri	1b
 
 	/* Maybe handle a signal */
-5:	/* get thread info from current task*/
-	lwi	r11, CURRENT_TASK, TS_THREAD_INFO;
-	lwi	r11, r11, TI_FLAGS;	/* get flags in thread info */
-	andi	r11, r11, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME;
-	beqi	r11, 1f;		/* Signals to handle, handle them */
+5:	
+	andi	r11, r19, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME;
+	beqi	r11, 4f;		/* Signals to handle, handle them */
 
 	addik	r5, r1, 0;		/* Arg 1: struct pt_regs *regs */
 	bralid	r15, do_notify_resume;	/* Handle any signals */
-	addi	r6, r0, 1;		/* Arg 2: int in_syscall */
+	add	r6, r30, r0;		/* Arg 2: int in_syscall */
+	add	r30, r0, r0		/* no more restarts */
+	bri	1b
 
 /* Finally, return to user state.  */
-1:	set_bip;			/*  Ints masked for state restore */
+4:	set_bip;			/*  Ints masked for state restore */
 	swi	CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); /* save current */
 	VM_OFF;
 	tophys(r1,r1);
@@ -464,6 +466,7 @@ C_ENTRY(ret_from_kernel_thread):
 	add	r3, r0, r0
 
 C_ENTRY(sys_rt_sigreturn_wrapper):
+	addik	r30, r0, 0		/* no restarts */
 	brid	sys_rt_sigreturn	/* Do real work */
 	addik	r5, r1, 0;		/* add user context as 1st arg */
 
@@ -571,20 +574,20 @@ C_ENTRY(ret_from_exc):
 
 	/* We're returning to user mode, so check for various conditions that
 	   trigger rescheduling. */
+1:
 	lwi	r11, CURRENT_TASK, TS_THREAD_INFO;	/* get thread info */
-	lwi	r11, r11, TI_FLAGS;	/* get flags in thread info */
-	andi	r11, r11, _TIF_NEED_RESCHED;
+	lwi	r19, r11, TI_FLAGS;	/* get flags in thread info */
+	andi	r11, r19, _TIF_NEED_RESCHED;
 	beqi	r11, 5f;
 
 /* Call the scheduler before returning from a syscall/trap. */
 	bralid	r15, schedule;	/* Call scheduler */
 	nop;				/* delay slot */
+	bri	1b
 
 	/* Maybe handle a signal */
-5:	lwi	r11, CURRENT_TASK, TS_THREAD_INFO;	/* get thread info */
-	lwi	r11, r11, TI_FLAGS;	/* get flags in thread info */
-	andi	r11, r11, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME;
-	beqi	r11, 1f;		/* Signals to handle, handle them */
+5:	andi	r11, r19, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME;
+	beqi	r11, 4f;		/* Signals to handle, handle them */
 
 	/*
 	 * Handle a signal return; Pending signals should be in r18.
@@ -600,9 +603,10 @@ C_ENTRY(ret_from_exc):
 	addik	r5, r1, 0;		/* Arg 1: struct pt_regs *regs */
 	bralid	r15, do_notify_resume;	/* Handle any signals */
 	addi	r6, r0, 0;		/* Arg 2: int in_syscall */
+	bri	1b
 
 /* Finally, return to user state.  */
-1:	set_bip;			/* Ints masked for state restore */
+4:	set_bip;			/* Ints masked for state restore */
 	swi	CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); /* save current */
 	VM_OFF;
 	tophys(r1,r1);
@@ -682,22 +686,23 @@ ret_from_irq:
 	lwi	r11, r1, PT_MODE;
 	bnei	r11, 2f;
 
+1:
 	lwi	r11, CURRENT_TASK, TS_THREAD_INFO;
-	lwi	r11, r11, TI_FLAGS; /* MS: get flags from thread info */
-	andi	r11, r11, _TIF_NEED_RESCHED;
+	lwi	r19, r11, TI_FLAGS; /* MS: get flags from thread info */
+	andi	r11, r19, _TIF_NEED_RESCHED;
 	beqi	r11, 5f
 	bralid	r15, schedule;
 	nop; /* delay slot */
+	bri	1b
 
     /* Maybe handle a signal */
-5:	lwi	r11, CURRENT_TASK, TS_THREAD_INFO; /* MS: get thread info */
-	lwi	r11, r11, TI_FLAGS; /* get flags in thread info */
-	andi	r11, r11, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME;
+5:	andi	r11, r19, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME;
 	beqid	r11, no_intr_resched
 /* Handle a signal return; Pending signals should be in r18. */
 	addik	r5, r1, 0; /* Arg 1: struct pt_regs *regs */
 	bralid	r15, do_notify_resume;	/* Handle any signals */
 	addi	r6, r0, 0; /* Arg 2: int in_syscall */
+	bri	1b
 
 /* Finally, return to user state. */
 no_intr_resched:
@@ -815,28 +820,29 @@ dbtrap_call: /* Return point for kernel/user entry + 8 because of rtsd r15, 8 */
 	lwi	r11, r1, PT_MODE;
 	bnei	r11, 2f;
 /* MS: Return to user space - gdb */
+1:
 	/* Get current task ptr into r11 */
 	lwi	r11, CURRENT_TASK, TS_THREAD_INFO;	/* get thread info */
-	lwi	r11, r11, TI_FLAGS;	/* get flags in thread info */
-	andi	r11, r11, _TIF_NEED_RESCHED;
+	lwi	r19, r11, TI_FLAGS;	/* get flags in thread info */
+	andi	r11, r19, _TIF_NEED_RESCHED;
 	beqi	r11, 5f;
 
 	/* Call the scheduler before returning from a syscall/trap. */
 	bralid	r15, schedule;	/* Call scheduler */
 	nop;				/* delay slot */
+	bri	1b
 
 	/* Maybe handle a signal */
-5:	lwi	r11, CURRENT_TASK, TS_THREAD_INFO;	/* get thread info */
-	lwi	r11, r11, TI_FLAGS;	/* get flags in thread info */
-	andi	r11, r11, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME;
-	beqi	r11, 1f;		/* Signals to handle, handle them */
+5:	andi	r11, r19, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME;
+	beqi	r11, 4f;		/* Signals to handle, handle them */
 
 	addik	r5, r1, 0;		/* Arg 1: struct pt_regs *regs */
 	bralid	r15, do_notify_resume;	/* Handle any signals */
 	addi  r6, r0, 0;	/* Arg 2: int in_syscall */
+	bri	1b
 
 /* Finally, return to user state.  */
-1:	swi	CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); /* save current */
+4:	swi	CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); /* save current */
 	VM_OFF;
 	tophys(r1,r1);
 	/* MS: Restore all regs */
diff --git a/arch/microblaze/kernel/ptrace.c b/arch/microblaze/kernel/ptrace.c
index ab1b9db661f..b050219c42e 100644
--- a/arch/microblaze/kernel/ptrace.c
+++ b/arch/microblaze/kernel/ptrace.c
@@ -164,29 +164,6 @@ asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
 		tracehook_report_syscall_exit(regs, step);
 }
 
-#if 0
-static asmlinkage void syscall_trace(void)
-{
-	if (!test_thread_flag(TIF_SYSCALL_TRACE))
-		return;
-	if (!(current->ptrace & PT_PTRACED))
-		return;
-	/* The 0x80 provides a way for the tracing parent to distinguish
-	 between a syscall stop and SIGTRAP delivery */
-	ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
-				? 0x80 : 0));
-	/*
-	 * this isn't the same as continuing with a signal, but it will do
-	 * for normal use. strace only continues with a signal if the
-	 * stopping signal is not SIGTRAP. -brl
-	 */
-	if (current->exit_code) {
-		send_sig(current->exit_code, current, 1);
-		current->exit_code = 0;
-	}
-}
-#endif
-
 void ptrace_disable(struct task_struct *child)
 {
 	/* nothing to do */
diff --git a/arch/microblaze/kernel/signal.c b/arch/microblaze/kernel/signal.c
index ac3d0a0f481..9f7a8bde068 100644
--- a/arch/microblaze/kernel/signal.c
+++ b/arch/microblaze/kernel/signal.c
@@ -41,13 +41,6 @@
 #include <asm/cacheflush.h>
 #include <asm/syscalls.h>
 
-asmlinkage long
-sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
-		struct pt_regs *regs)
-{
-	return do_sigaltstack(uss, uoss, regs->r1);
-}
-
 /*
  * Do a signal return; undo the signal stack.
  */
@@ -109,9 +102,7 @@ asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
 	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &rval))
 		goto badframe;
 
-	/* It is more difficult to avoid calling this function than to
-	 call it and ignore errors. */
-	if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->r1) == -EFAULT)
+	if (restore_altstack(&frame->uc.uc_stack))
 		goto badframe;
 
 	return rval;
@@ -194,11 +185,7 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 	/* Create the ucontext. */
 	err |= __put_user(0, &frame->uc.uc_flags);
 	err |= __put_user(NULL, &frame->uc.uc_link);
-	err |= __put_user((void __user *)current->sas_ss_sp,
-			&frame->uc.uc_stack.ss_sp);
-	err |= __put_user(sas_ss_flags(regs->r1),
-			&frame->uc.uc_stack.ss_flags);
-	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
+	err |= __save_altstack(&frame->uc.uc_stack, regs->r1);
 	err |= setup_sigcontext(&frame->uc.uc_mcontext,
 			regs, set->sig[0]);
 	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
@@ -356,15 +343,6 @@ static void do_signal(struct pt_regs *regs, int in_syscall)
 
 asmlinkage void do_notify_resume(struct pt_regs *regs, int in_syscall)
 {
-	/*
-	 * We want the common case to go fast, which
-	 * is why we may in certain cases get here from
-	 * kernel mode. Just return without doing anything
-	 * if so.
-	 */
-	if (kernel_mode(regs))
-		return;
-
 	if (test_thread_flag(TIF_SIGPENDING))
 		do_signal(regs, in_syscall);