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

Pull big execve/kernel_thread/fork unification series from Al Viro:
 "All architectures are converted to new model.  Quite a bit of that
  stuff is actually shared with architecture trees; in such cases it's
  literally shared branch pulled by both, not a cherry-pick.

  A lot of ugliness and black magic is gone (-3KLoC total in this one):

   - kernel_thread()/kernel_execve()/sys_execve() redesign.

     We don't do syscalls from kernel anymore for either kernel_thread()
     or kernel_execve():

     kernel_thread() is essentially clone(2) with callback run before we
     return to userland, the callbacks either never return or do
     successful do_execve() before returning.

     kernel_execve() is a wrapper for do_execve() - it doesn't need to
     do transition to user mode anymore.

     As a result kernel_thread() and kernel_execve() are
     arch-independent now - they live in kernel/fork.c and fs/exec.c
     resp.  sys_execve() is also in fs/exec.c and it's completely
     architecture-independent.

   - daemonize() is gone, along with its parts in fs/*.c

   - struct pt_regs * is no longer passed to do_fork/copy_process/
     copy_thread/do_execve/search_binary_handler/->load_binary/do_coredump.

   - sys_fork()/sys_vfork()/sys_clone() unified; some architectures
     still need wrappers (ones with callee-saved registers not saved in
     pt_regs on syscall entry), but the main part of those suckers is in
     kernel/fork.c now."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (113 commits)
  do_coredump(): get rid of pt_regs argument
  print_fatal_signal(): get rid of pt_regs argument
  ptrace_signal(): get rid of unused arguments
  get rid of ptrace_signal_deliver() arguments
  new helper: signal_pt_regs()
  unify default ptrace_signal_deliver
  flagday: kill pt_regs argument of do_fork()
  death to idle_regs()
  don't pass regs to copy_process()
  flagday: don't pass regs to copy_thread()
  bfin: switch to generic vfork, get rid of pointless wrappers
  xtensa: switch to generic clone()
  openrisc: switch to use of generic fork and clone
  unicore32: switch to generic clone(2)
  score: switch to generic fork/vfork/clone
  c6x: sanitize copy_thread(), get rid of clone(2) wrapper, switch to generic clone()
  take sys_fork/sys_vfork/sys_clone prototypes to linux/syscalls.h
  mn10300: switch to generic fork/vfork/clone
  h8300: switch to generic fork/vfork/clone
  tile: switch to generic clone()
  ...

Conflicts:
	arch/microblaze/include/asm/Kbuild

7 files changed, 10 insertions, 35 deletions

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 2adf340b8589..f9ccff915918 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -33,6 +33,7 @@ config ARM64
 	select RTC_LIB
 	select SPARSE_IRQ
 	select SYSCTL_EXCEPTION_TRACE
+	select CLONE_BACKWARDS
 	help
 	  ARM 64-bit (AArch64) Linux support.
 
diff --git a/arch/arm64/include/asm/syscalls.h b/arch/arm64/include/asm/syscalls.h
index a1b00cd6f786..20d63b290665 100644
--- a/arch/arm64/include/asm/syscalls.h
+++ b/arch/arm64/include/asm/syscalls.h
@@ -27,12 +27,6 @@ asmlinkage long sys_rt_sigreturn_wrapper(void);
 asmlinkage long sys_sigaltstack_wrapper(const stack_t __user *uss,
 					stack_t __user *uoss);
 
-/*
- * AArch64 sys_clone implementation has a different prototype than the generic
- * one (additional TLS value argument).
- */
-#define sys_clone	sys_clone
-
 #include <asm-generic/syscalls.h>
 
 #endif	/* __ASM_SYSCALLS_H */
diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h
index 43064a8bd99e..d69aeea6da1e 100644
--- a/arch/arm64/include/asm/unistd.h
+++ b/arch/arm64/include/asm/unistd.h
@@ -24,6 +24,9 @@
 #define __ARCH_WANT_SYS_SIGPROCMASK
 #define __ARCH_WANT_COMPAT_SYS_RT_SIGSUSPEND
 #define __ARCH_WANT_COMPAT_SYS_SENDFILE
+#define __ARCH_WANT_SYS_FORK
+#define __ARCH_WANT_SYS_VFORK
 #endif
 #define __ARCH_WANT_SYS_EXECVE
+#define __ARCH_WANT_SYS_CLONE
 #include <uapi/asm/unistd.h>
diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h
index 50104e8ce55d..58432625fdb3 100644
--- a/arch/arm64/include/asm/unistd32.h
+++ b/arch/arm64/include/asm/unistd32.h
@@ -23,7 +23,7 @@
 
 __SYSCALL(0,   sys_restart_syscall)
 __SYSCALL(1,   sys_exit)
-__SYSCALL(2,   compat_sys_fork)
+__SYSCALL(2,   sys_fork)
 __SYSCALL(3,   sys_read)
 __SYSCALL(4,   sys_write)
 __SYSCALL(5,   compat_sys_open)
@@ -211,7 +211,7 @@ __SYSCALL(186, compat_sys_sigaltstack_wrapper)
 __SYSCALL(187, compat_sys_sendfile)
 __SYSCALL(188, sys_ni_syscall)			/* 188 reserved */
 __SYSCALL(189, sys_ni_syscall)			/* 189 reserved */
-__SYSCALL(190, compat_sys_vfork)
+__SYSCALL(190, sys_vfork)
 __SYSCALL(191, compat_sys_getrlimit)		/* SuS compliant getrlimit */
 __SYSCALL(192, sys_mmap_pgoff)
 __SYSCALL(193, compat_sys_truncate64_wrapper)
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 8a5f3341861e..cb0956bc96ed 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -234,16 +234,15 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 asmlinkage void ret_from_fork(void) asm("ret_from_fork");
 
 int copy_thread(unsigned long clone_flags, unsigned long stack_start,
-		unsigned long stk_sz, struct task_struct *p,
-		struct pt_regs *regs)
+		unsigned long stk_sz, struct task_struct *p)
 {
 	struct pt_regs *childregs = task_pt_regs(p);
 	unsigned long tls = p->thread.tp_value;
 
 	memset(&p->thread.cpu_context, 0, sizeof(struct cpu_context));
 
-	if (likely(regs)) {
-		*childregs = *regs;
+	if (likely(!(p->flags & PF_KTHREAD))) {
+		*childregs = *current_pt_regs();
 		childregs->regs[0] = 0;
 		if (is_compat_thread(task_thread_info(p))) {
 			if (stack_start)
@@ -266,7 +265,7 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start,
 		 * for the new thread.
 		 */
 		if (clone_flags & CLONE_SETTLS)
-			tls = regs->regs[3];
+			tls = childregs->regs[3];
 	} else {
 		memset(childregs, 0, sizeof(struct pt_regs));
 		childregs->pstate = PSR_MODE_EL1h;
diff --git a/arch/arm64/kernel/sys.c b/arch/arm64/kernel/sys.c
index 4364df85050e..8292a9b090f8 100644
--- a/arch/arm64/kernel/sys.c
+++ b/arch/arm64/kernel/sys.c
@@ -26,17 +26,6 @@
 #include <linux/slab.h>
 #include <linux/syscalls.h>
 
-/*
- * Clone a task - this clones the calling program thread.
- */
-asmlinkage long sys_clone(unsigned long clone_flags, unsigned long newsp,
-			  int __user *parent_tidptr, unsigned long tls_val,
-			  int __user *child_tidptr)
-{
-	return do_fork(clone_flags, newsp, current_pt_regs(), 0,
-			parent_tidptr, child_tidptr);
-}
-
 asmlinkage long sys_mmap(unsigned long addr, unsigned long len,
 			 unsigned long prot, unsigned long flags,
 			 unsigned long fd, off_t off)
diff --git a/arch/arm64/kernel/sys_compat.c b/arch/arm64/kernel/sys_compat.c
index 6fabc1912da0..f7b05edf8ce3 100644
--- a/arch/arm64/kernel/sys_compat.c
+++ b/arch/arm64/kernel/sys_compat.c
@@ -28,17 +28,6 @@
 #include <asm/cacheflush.h>
 #include <asm/unistd32.h>
 
-asmlinkage int compat_sys_fork(void)
-{
-	return do_fork(SIGCHLD, 0, current_pt_regs(), 0, NULL, NULL);
-}
-
-asmlinkage int compat_sys_vfork(void)
-{
-	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, 0,
-		       current_pt_regs(), 0, NULL, NULL);
-}
-
 asmlinkage int compat_sys_sched_rr_get_interval(compat_pid_t pid,
 						struct compat_timespec __user *interval)
 {