microblaze: switch to generic kernel_execve()

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

5 files changed, 6 insertions, 43 deletions

diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index 3b8df669eecd..198abf6d41c4 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -27,6 +27,7 @@ config MICROBLAZE
         select GENERIC_CLOCKEVENTS
         select MODULES_USE_ELF_RELA
         select GENERIC_KERNEL_THREAD
+        select GENERIC_KERNEL_EXECVE
 
 config SWAP
         def_bool n
diff --git a/arch/microblaze/kernel/entry-nommu.S b/arch/microblaze/kernel/entry-nommu.S
index c47e92cd7e78..8957c7760c47 100644
--- a/arch/microblaze/kernel/entry-nommu.S
+++ b/arch/microblaze/kernel/entry-nommu.S
@@ -479,8 +479,8 @@ ENTRY(ret_from_kernel_thread)
         addk    r5, r0, r3
         brald   r15, r20
         addk    r5, r0, r19
-        brid    sys_exit        /* won't be returning... */
-        addk    r5, r0, r0
+        brid    ret_to_user
+        addk    r3, r0, r0
 
 work_pending:
         enable_irq
diff --git a/arch/microblaze/kernel/entry.S b/arch/microblaze/kernel/entry.S
index be76d1338be0..9aa54def9985 100644
--- a/arch/microblaze/kernel/entry.S
+++ b/arch/microblaze/kernel/entry.S
@@ -293,24 +293,6 @@ C_ENTRY(_user_exception):
         swi     r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) /* save stack */
         addi    r14, r14, 4     /* return address is 4 byte after call */
 
-        mfs     r1, rmsr
-        nop
-        andi    r1, r1, MSR_UMS
-        bnei    r1, 1f
-
-/* Kernel-mode state save - kernel execve */
-        lwi     r1, r0, TOPHYS(PER_CPU(ENTRY_SP)); /* Reload kernel stack-ptr*/
-        tophys(r1,r1);
-
-        addik   r1, r1, -PT_SIZE; /* Make room on the stack. */
-        SAVE_REGS
-
-        swi     r1, r1, PT_MODE; /* pt_regs -> kernel mode */
-        brid    2f;
-        nop;                            /* Fill delay slot */
-
-/* User-mode state save.  */
-1:
         lwi     r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */
         tophys(r1,r1);
         lwi     r1, r1, TS_THREAD_INFO; /* get stack from task_struct */
@@ -490,8 +472,8 @@ C_ENTRY(ret_from_kernel_thread):
                                 /* ( in the delay slot ) */
         brald   r15, r20        /* fn was left in r20 */
         addk    r5, r0, r19     /* ... and argument - in r19 */
-        brid    sys_exit        /* won't be returning... */
-        addk    r5, r0, r0
+        brid    ret_from_trap
+        add     r3, r0, r0
 
 C_ENTRY(sys_vfork):
         brid    microblaze_vfork        /* Do real work (tail-call) */
diff --git a/arch/microblaze/kernel/process.c b/arch/microblaze/kernel/process.c
index cbf8bb92f159..29768c3dc358 100644
--- a/arch/microblaze/kernel/process.c
+++ b/arch/microblaze/kernel/process.c
@@ -215,6 +215,7 @@ void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long usp)
         regs->pt_mode = 0;
 #ifdef CONFIG_MMU
         regs->msr |= MSR_UMS;
+        regs->msr &= ~MSR_VM;
 #endif
 }
 
diff --git a/arch/microblaze/kernel/sys_microblaze.c b/arch/microblaze/kernel/sys_microblaze.c
index 404c0f24bd41..b200ee7d1da9 100644
--- a/arch/microblaze/kernel/sys_microblaze.c
+++ b/arch/microblaze/kernel/sys_microblaze.c
@@ -75,24 +75,3 @@ asmlinkage long sys_mmap(unsigned long addr, unsigned long len,
 
         return sys_mmap_pgoff(addr, len, prot, flags, fd, pgoff >> PAGE_SHIFT);
 }
-
-/*
- * Do a system call from kernel instead of calling sys_execve so we
- * end up with proper pt_regs.
- */
-int kernel_execve(const char *filename,
-                  const char *const argv[],
-                  const char *const envp[])
-{
-        register const char *__a __asm__("r5") = filename;
-        register const void *__b __asm__("r6") = argv;
-        register const void *__c __asm__("r7") = envp;
-        register unsigned long __syscall __asm__("r12") = __NR_execve;
-        register unsigned long __ret __asm__("r3");
-        __asm__ __volatile__ ("brki r14, 0x8"
-                        : "=r" (__ret), "=r" (__syscall)
-                        : "1" (__syscall), "r" (__a), "r" (__b), "r" (__c)
-                        : "r4", "r8", "r9",
-                        "r10", "r11", "r14", "cc", "memory");
-        return __ret;
-}