microblaze: switch to generic fork/vfork/clone

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

7 files changed, 12 insertions, 56 deletions

diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index 198abf6d41c4..4bcf89148f3c 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -28,6 +28,7 @@ config MICROBLAZE
         select MODULES_USE_ELF_RELA
         select GENERIC_KERNEL_THREAD
         select GENERIC_KERNEL_EXECVE
+        select CLONE_BACKWARDS
 
 config SWAP
         def_bool n
diff --git a/arch/microblaze/include/asm/unistd.h b/arch/microblaze/include/asm/unistd.h
index ea7442834294..94d978986b75 100644
--- a/arch/microblaze/include/asm/unistd.h
+++ b/arch/microblaze/include/asm/unistd.h
@@ -423,6 +423,11 @@
 #define __ARCH_WANT_SYS_RT_SIGACTION
 #define __ARCH_WANT_SYS_RT_SIGSUSPEND
 #define __ARCH_WANT_SYS_EXECVE
+#define __ARCH_WANT_SYS_CLONE
+#define __ARCH_WANT_SYS_VFORK
+#ifdef CONFIG_MMU
+#define __ARCH_WANT_SYS_FORK
+#endif
 
 /*
  * "Conditional" syscalls
diff --git a/arch/microblaze/kernel/entry-nommu.S b/arch/microblaze/kernel/entry-nommu.S
index 673a49c04a02..cb0327f204ab 100644
--- a/arch/microblaze/kernel/entry-nommu.S
+++ b/arch/microblaze/kernel/entry-nommu.S
@@ -559,14 +559,6 @@ no_work_pending:
         rtid    r14, 0
         nop
 
-sys_vfork:
-        brid    microblaze_vfork
-        addk    r5, r1, r0
-
-sys_clone:
-        brid    microblaze_clone
-        addk    r7, r1, r0
-
 sys_rt_sigreturn_wrapper:
         brid    sys_rt_sigreturn
         addk    r5, r1, r0
diff --git a/arch/microblaze/kernel/entry.S b/arch/microblaze/kernel/entry.S
index 10f360ed82b4..c217367dfc7b 100644
--- a/arch/microblaze/kernel/entry.S
+++ b/arch/microblaze/kernel/entry.S
@@ -442,18 +442,6 @@ TRAP_return:		/* Make global symbol for debugging */
         nop;
 
 
-/* These syscalls need access to the struct pt_regs on the stack, so we
-   implement them in assembly (they're basically all wrappers anyway).  */
-
-C_ENTRY(sys_fork_wrapper):
-        addi    r5, r0, SIGCHLD                 /* Arg 0: flags */
-        lwi     r6, r1, PT_R1   /* Arg 1: child SP (use parent's) */
-        addik   r7, r1, 0                       /* Arg 2: parent context */
-        add     r8, r0, r0                      /* Arg 3: (unused) */
-        add     r9, r0, r0;                     /* Arg 4: (unused) */
-        brid    do_fork         /* Do real work (tail-call) */
-        add     r10, r0, r0;                    /* Arg 5: (unused) */
-
 /* This the initial entry point for a new child thread, with an appropriate
    stack in place that makes it look the the child is in the middle of an
    syscall.  This function is actually `returned to' from switch_thread
@@ -475,20 +463,6 @@ C_ENTRY(ret_from_kernel_thread):
         brid    ret_from_trap
         add     r3, r0, r0
 
-C_ENTRY(sys_vfork):
-        brid    microblaze_vfork        /* Do real work (tail-call) */
-        addik   r5, r1, 0
-
-C_ENTRY(sys_clone):
-        bnei    r6, 1f;                 /* See if child SP arg (arg 1) is 0. */
-        lwi     r6, r1, PT_R1;  /* If so, use paret's stack ptr */
-1:      addik   r7, r1, 0;                      /* Arg 2: parent context */
-        lwi     r9, r1, PT_R8;          /* parent tid.  */
-        lwi     r10, r1, PT_R9;         /* child tid.  */
-        /* do_fork will pick up TLS from regs->r10.  */
-        brid    do_fork         /* Do real work (tail-call) */
-        add     r8, r0, r0;             /* Arg 3: (unused) */
-
 C_ENTRY(sys_rt_sigreturn_wrapper):
         brid    sys_rt_sigreturn        /* Do real work */
         addik   r5, r1, 0;              /* add user context as 1st arg */
diff --git a/arch/microblaze/kernel/process.c b/arch/microblaze/kernel/process.c
index 29768c3dc358..a5fed8db7263 100644
--- a/arch/microblaze/kernel/process.c
+++ b/arch/microblaze/kernel/process.c
@@ -13,6 +13,7 @@
 #include <linux/pm.h>
 #include <linux/tick.h>
 #include <linux/bitops.h>
+#include <linux/ptrace.h>
 #include <asm/pgalloc.h>
 #include <asm/uaccess.h> /* for USER_DS macros */
 #include <asm/cacheflush.h>
@@ -120,7 +121,7 @@ void flush_thread(void)
 
 int copy_thread(unsigned long clone_flags, unsigned long usp,
                 unsigned long arg,
-                struct task_struct *p, struct pt_regs *regs)
+                struct task_struct *p, struct pt_regs *unused)
 {
         struct pt_regs *childregs = task_pt_regs(p);
         struct thread_info *ti = task_thread_info(p);
@@ -141,8 +142,9 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
                 ti->cpu_context.r15 = (unsigned long)ret_from_kernel_thread - 8;
                 return 0;
         }
-        *childregs = *regs;
-        childregs->r1 = usp;
+        *childregs = *current_pt_regs();
+        if (usp)
+                childregs->r1 = usp;
 
         memset(&ti->cpu_context, 0, sizeof(struct cpu_context));
         ti->cpu_context.r1 = (unsigned long)childregs;
diff --git a/arch/microblaze/kernel/sys_microblaze.c b/arch/microblaze/kernel/sys_microblaze.c
index a6a7bae9f5c6..63647c586b43 100644
--- a/arch/microblaze/kernel/sys_microblaze.c
+++ b/arch/microblaze/kernel/sys_microblaze.c
@@ -34,20 +34,6 @@
 
 #include <asm/syscalls.h>
 
-asmlinkage long microblaze_vfork(struct pt_regs *regs)
-{
-        return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->r1,
-                                                regs, 0, NULL, NULL);
-}
-
-asmlinkage long microblaze_clone(int flags, unsigned long stack,
-                                                        struct pt_regs *regs)
-{
-        if (!stack)
-                stack = regs->r1;
-        return do_fork(flags, stack, regs, 0, NULL, NULL);
-}
-
 asmlinkage long sys_mmap(unsigned long addr, unsigned long len,
                         unsigned long prot, unsigned long flags,
                         unsigned long fd, off_t pgoff)
diff --git a/arch/microblaze/kernel/syscall_table.S b/arch/microblaze/kernel/syscall_table.S
index 6a2b294ef6dc..ff6431e54680 100644
--- a/arch/microblaze/kernel/syscall_table.S
+++ b/arch/microblaze/kernel/syscall_table.S
@@ -2,11 +2,7 @@ ENTRY(sys_call_table)
         .long sys_restart_syscall       /* 0 - old "setup()" system call,
                                          * used for restarting */
         .long sys_exit
-#ifdef CONFIG_MMU
-        .long sys_fork_wrapper
-#else
-        .long sys_ni_syscall
-#endif
+        .long sys_fork
         .long sys_read
         .long sys_write
         .long sys_open                  /* 5 */