arm64: Use generic kernel_execve() implementation

This patch enables CONFIG_GENERIC_KERNEL_EXECVE on arm64 and removes the
arm64-specific implementation of kernel_execve().

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

3 files changed, 2 insertions, 44 deletions

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 4077b71b1258..75b212d5db9d 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -6,6 +6,7 @@ config ARM64
         select GENERIC_IOMAP
         select GENERIC_IRQ_PROBE
         select GENERIC_IRQ_SHOW
+        select GENERIC_KERNEL_EXECVE
         select GENERIC_KERNEL_THREAD
         select GENERIC_SMP_IDLE_THREAD
         select GENERIC_TIME_VSYSCALL
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 08db8972ebcc..00daf922733e 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -594,7 +594,7 @@ work_resched:
 /*
  * "slow" syscall return path.
  */
-ENTRY(ret_to_user)
+ret_to_user:
         disable_irq                             // disable interrupts
         ldr     x1, [tsk, #TI_FLAGS]
         and     x2, x1, #_TIF_WORK_MASK
diff --git a/arch/arm64/kernel/sys.c b/arch/arm64/kernel/sys.c
index b120df37de35..4deb0d0093cd 100644
--- a/arch/arm64/kernel/sys.c
+++ b/arch/arm64/kernel/sys.c
@@ -62,49 +62,6 @@ out:
         return error;
 }
 
-int kernel_execve(const char *filename,
-                  const char *const argv[],
-                  const char *const envp[])
-{
-        struct pt_regs regs;
-        int ret;
-
-        memset(&regs, 0, sizeof(struct pt_regs));
-        ret = do_execve(filename,
-                        (const char __user *const __user *)argv,
-                        (const char __user *const __user *)envp, &regs);
-        if (ret < 0)
-                goto out;
-
-        /*
-         * Save argc to the register structure for userspace.
-         */
-        regs.regs[0] = ret;
-
-        /*
-         * We were successful.  We won't be returning to our caller, but
-         * instead to user space by manipulating the kernel stack.
-         */
-        asm(    "add    x0, %0, %1\n\t"
-                "mov    x1, %2\n\t"
-                "mov    x2, %3\n\t"
-                "bl     memmove\n\t"    /* copy regs to top of stack */
-                "mov    x27, #0\n\t"    /* not a syscall */
-                "mov    x28, %0\n\t"    /* thread structure */
-                "mov    sp, x0\n\t"     /* reposition stack pointer */
-                "b      ret_to_user"
-                :
-                : "r" (current_thread_info()),
-                  "Ir" (THREAD_START_SP - sizeof(regs)),
-                  "r" (&regs),
-                  "Ir" (sizeof(regs))
-                : "x0", "x1", "x2", "x27", "x28", "x30", "memory");
-
- out:
-        return ret;
-}
-EXPORT_SYMBOL(kernel_execve);
-
 asmlinkage long sys_mmap(unsigned long addr, unsigned long len,
                          unsigned long prot, unsigned long flags,
                          unsigned long fd, off_t off)