init android origin source code

1 files changed, 406 insertions, 0 deletions

diff --git a/ANDROID_3.4.5/arch/s390/lib/uaccess_pt.c b/ANDROID_3.4.5/arch/s390/lib/uaccess_pt.c
new file mode 100644
index 00000000..342ae35a
--- /dev/null
+++ b/ANDROID_3.4.5/arch/s390/lib/uaccess_pt.c
@@ -0,0 +1,406 @@
+/*
+ *  arch/s390/lib/uaccess_pt.c
+ *
+ *  User access functions based on page table walks for enhanced
+ *  system layout without hardware support.
+ *
+ *    Copyright IBM Corp. 2006
+ *    Author(s): Gerald Schaefer (gerald.schaefer@de.ibm.com)
+ */
+
+#include <linux/errno.h>
+#include <linux/hardirq.h>
+#include <linux/mm.h>
+#include <asm/uaccess.h>
+#include <asm/futex.h>
+#include "uaccess.h"
+
+static inline pte_t *follow_table(struct mm_struct *mm, unsigned long addr)
+{
+	pgd_t *pgd;
+	pud_t *pud;
+	pmd_t *pmd;
+
+	pgd = pgd_offset(mm, addr);
+	if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
+		return (pte_t *) 0x3a;
+
+	pud = pud_offset(pgd, addr);
+	if (pud_none(*pud) || unlikely(pud_bad(*pud)))
+		return (pte_t *) 0x3b;
+
+	pmd = pmd_offset(pud, addr);
+	if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
+		return (pte_t *) 0x10;
+
+	return pte_offset_map(pmd, addr);
+}
+
+static __always_inline size_t __user_copy_pt(unsigned long uaddr, void *kptr,
+					     size_t n, int write_user)
+{
+	struct mm_struct *mm = current->mm;
+	unsigned long offset, pfn, done, size;
+	pte_t *pte;
+	void *from, *to;
+
+	done = 0;
+retry:
+	spin_lock(&mm->page_table_lock);
+	do {
+		pte = follow_table(mm, uaddr);
+		if ((unsigned long) pte < 0x1000)
+			goto fault;
+		if (!pte_present(*pte)) {
+			pte = (pte_t *) 0x11;
+			goto fault;
+		} else if (write_user && !pte_write(*pte)) {
+			pte = (pte_t *) 0x04;
+			goto fault;
+		}
+
+		pfn = pte_pfn(*pte);
+		offset = uaddr & (PAGE_SIZE - 1);
+		size = min(n - done, PAGE_SIZE - offset);
+		if (write_user) {
+			to = (void *)((pfn << PAGE_SHIFT) + offset);
+			from = kptr + done;
+		} else {
+			from = (void *)((pfn << PAGE_SHIFT) + offset);
+			to = kptr + done;
+		}
+		memcpy(to, from, size);
+		done += size;
+		uaddr += size;
+	} while (done < n);
+	spin_unlock(&mm->page_table_lock);
+	return n - done;
+fault:
+	spin_unlock(&mm->page_table_lock);
+	if (__handle_fault(uaddr, (unsigned long) pte, write_user))
+		return n - done;
+	goto retry;
+}
+
+/*
+ * Do DAT for user address by page table walk, return kernel address.
+ * This function needs to be called with current->mm->page_table_lock held.
+ */
+static __always_inline unsigned long __dat_user_addr(unsigned long uaddr)
+{
+	struct mm_struct *mm = current->mm;
+	unsigned long pfn;
+	pte_t *pte;
+	int rc;
+
+retry:
+	pte = follow_table(mm, uaddr);
+	if ((unsigned long) pte < 0x1000)
+		goto fault;
+	if (!pte_present(*pte)) {
+		pte = (pte_t *) 0x11;
+		goto fault;
+	}
+
+	pfn = pte_pfn(*pte);
+	return (pfn << PAGE_SHIFT) + (uaddr & (PAGE_SIZE - 1));
+fault:
+	spin_unlock(&mm->page_table_lock);
+	rc = __handle_fault(uaddr, (unsigned long) pte, 0);
+	spin_lock(&mm->page_table_lock);
+	if (!rc)
+		goto retry;
+	return 0;
+}
+
+size_t copy_from_user_pt(size_t n, const void __user *from, void *to)
+{
+	size_t rc;
+
+	if (segment_eq(get_fs(), KERNEL_DS)) {
+		memcpy(to, (void __kernel __force *) from, n);
+		return 0;
+	}
+	rc = __user_copy_pt((unsigned long) from, to, n, 0);
+	if (unlikely(rc))
+		memset(to + n - rc, 0, rc);
+	return rc;
+}
+
+size_t copy_to_user_pt(size_t n, void __user *to, const void *from)
+{
+	if (segment_eq(get_fs(), KERNEL_DS)) {
+		memcpy((void __kernel __force *) to, from, n);
+		return 0;
+	}
+	return __user_copy_pt((unsigned long) to, (void *) from, n, 1);
+}
+
+static size_t clear_user_pt(size_t n, void __user *to)
+{
+	long done, size, ret;
+
+	if (segment_eq(get_fs(), KERNEL_DS)) {
+		memset((void __kernel __force *) to, 0, n);
+		return 0;
+	}
+	done = 0;
+	do {
+		if (n - done > PAGE_SIZE)
+			size = PAGE_SIZE;
+		else
+			size = n - done;
+		ret = __user_copy_pt((unsigned long) to + done,
+				      &empty_zero_page, size, 1);
+		done += size;
+		if (ret)
+			return ret + n - done;
+	} while (done < n);
+	return 0;
+}
+
+static size_t strnlen_user_pt(size_t count, const char __user *src)
+{
+	char *addr;
+	unsigned long uaddr = (unsigned long) src;
+	struct mm_struct *mm = current->mm;
+	unsigned long offset, pfn, done, len;
+	pte_t *pte;
+	size_t len_str;
+
+	if (segment_eq(get_fs(), KERNEL_DS))
+		return strnlen((const char __kernel __force *) src, count) + 1;
+	done = 0;
+retry:
+	spin_lock(&mm->page_table_lock);
+	do {
+		pte = follow_table(mm, uaddr);
+		if ((unsigned long) pte < 0x1000)
+			goto fault;
+		if (!pte_present(*pte)) {
+			pte = (pte_t *) 0x11;
+			goto fault;
+		}
+
+		pfn = pte_pfn(*pte);
+		offset = uaddr & (PAGE_SIZE-1);
+		addr = (char *)(pfn << PAGE_SHIFT) + offset;
+		len = min(count - done, PAGE_SIZE - offset);
+		len_str = strnlen(addr, len);
+		done += len_str;
+		uaddr += len_str;
+	} while ((len_str == len) && (done < count));
+	spin_unlock(&mm->page_table_lock);
+	return done + 1;
+fault:
+	spin_unlock(&mm->page_table_lock);
+	if (__handle_fault(uaddr, (unsigned long) pte, 0))
+		return 0;
+	goto retry;
+}
+
+static size_t strncpy_from_user_pt(size_t count, const char __user *src,
+				   char *dst)
+{
+	size_t n = strnlen_user_pt(count, src);
+
+	if (!n)
+		return -EFAULT;
+	if (n > count)
+		n = count;
+	if (segment_eq(get_fs(), KERNEL_DS)) {
+		memcpy(dst, (const char __kernel __force *) src, n);
+		if (dst[n-1] == '\0')
+			return n-1;
+		else
+			return n;
+	}
+	if (__user_copy_pt((unsigned long) src, dst, n, 0))
+		return -EFAULT;
+	if (dst[n-1] == '\0')
+		return n-1;
+	else
+		return n;
+}
+
+static size_t copy_in_user_pt(size_t n, void __user *to,
+			      const void __user *from)
+{
+	struct mm_struct *mm = current->mm;
+	unsigned long offset_from, offset_to, offset_max, pfn_from, pfn_to,
+		      uaddr, done, size, error_code;
+	unsigned long uaddr_from = (unsigned long) from;
+	unsigned long uaddr_to = (unsigned long) to;
+	pte_t *pte_from, *pte_to;
+	int write_user;
+
+	if (segment_eq(get_fs(), KERNEL_DS)) {
+		memcpy((void __force *) to, (void __force *) from, n);
+		return 0;
+	}
+	done = 0;
+retry:
+	spin_lock(&mm->page_table_lock);
+	do {
+		write_user = 0;
+		uaddr = uaddr_from;
+		pte_from = follow_table(mm, uaddr_from);
+		error_code = (unsigned long) pte_from;
+		if (error_code < 0x1000)
+			goto fault;
+		if (!pte_present(*pte_from)) {
+			error_code = 0x11;
+			goto fault;
+		}
+
+		write_user = 1;
+		uaddr = uaddr_to;
+		pte_to = follow_table(mm, uaddr_to);
+		error_code = (unsigned long) pte_to;
+		if (error_code < 0x1000)
+			goto fault;
+		if (!pte_present(*pte_to)) {
+			error_code = 0x11;
+			goto fault;
+		} else if (!pte_write(*pte_to)) {
+			error_code = 0x04;
+			goto fault;
+		}
+
+		pfn_from = pte_pfn(*pte_from);
+		pfn_to = pte_pfn(*pte_to);
+		offset_from = uaddr_from & (PAGE_SIZE-1);
+		offset_to = uaddr_from & (PAGE_SIZE-1);
+		offset_max = max(offset_from, offset_to);
+		size = min(n - done, PAGE_SIZE - offset_max);
+
+		memcpy((void *)(pfn_to << PAGE_SHIFT) + offset_to,
+		       (void *)(pfn_from << PAGE_SHIFT) + offset_from, size);
+		done += size;
+		uaddr_from += size;
+		uaddr_to += size;
+	} while (done < n);
+	spin_unlock(&mm->page_table_lock);
+	return n - done;
+fault:
+	spin_unlock(&mm->page_table_lock);
+	if (__handle_fault(uaddr, error_code, write_user))
+		return n - done;
+	goto retry;
+}
+
+#define __futex_atomic_op(insn, ret, oldval, newval, uaddr, oparg)	\
+	asm volatile("0: l   %1,0(%6)\n"				\
+		     "1: " insn						\
+		     "2: cs  %1,%2,0(%6)\n"				\
+		     "3: jl  1b\n"					\
+		     "   lhi %0,0\n"					\
+		     "4:\n"						\
+		     EX_TABLE(0b,4b) EX_TABLE(2b,4b) EX_TABLE(3b,4b)	\
+		     : "=d" (ret), "=&d" (oldval), "=&d" (newval),	\
+		       "=m" (*uaddr)					\
+		     : "0" (-EFAULT), "d" (oparg), "a" (uaddr),		\
+		       "m" (*uaddr) : "cc" );
+
+static int __futex_atomic_op_pt(int op, u32 __user *uaddr, int oparg, int *old)
+{
+	int oldval = 0, newval, ret;
+
+	switch (op) {
+	case FUTEX_OP_SET:
+		__futex_atomic_op("lr %2,%5\n",
+				  ret, oldval, newval, uaddr, oparg);
+		break;
+	case FUTEX_OP_ADD:
+		__futex_atomic_op("lr %2,%1\nar %2,%5\n",
+				  ret, oldval, newval, uaddr, oparg);
+		break;
+	case FUTEX_OP_OR:
+		__futex_atomic_op("lr %2,%1\nor %2,%5\n",
+				  ret, oldval, newval, uaddr, oparg);
+		break;
+	case FUTEX_OP_ANDN:
+		__futex_atomic_op("lr %2,%1\nnr %2,%5\n",
+				  ret, oldval, newval, uaddr, oparg);
+		break;
+	case FUTEX_OP_XOR:
+		__futex_atomic_op("lr %2,%1\nxr %2,%5\n",
+				  ret, oldval, newval, uaddr, oparg);
+		break;
+	default:
+		ret = -ENOSYS;
+	}
+	if (ret == 0)
+		*old = oldval;
+	return ret;
+}
+
+int futex_atomic_op_pt(int op, u32 __user *uaddr, int oparg, int *old)
+{
+	int ret;
+
+	if (segment_eq(get_fs(), KERNEL_DS))
+		return __futex_atomic_op_pt(op, uaddr, oparg, old);
+	spin_lock(&current->mm->page_table_lock);
+	uaddr = (u32 __force __user *)
+		__dat_user_addr((__force unsigned long) uaddr);
+	if (!uaddr) {
+		spin_unlock(&current->mm->page_table_lock);
+		return -EFAULT;
+	}
+	get_page(virt_to_page(uaddr));
+	spin_unlock(&current->mm->page_table_lock);
+	ret = __futex_atomic_op_pt(op, uaddr, oparg, old);
+	put_page(virt_to_page(uaddr));
+	return ret;
+}
+
+static int __futex_atomic_cmpxchg_pt(u32 *uval, u32 __user *uaddr,
+				     u32 oldval, u32 newval)
+{
+	int ret;
+
+	asm volatile("0: cs   %1,%4,0(%5)\n"
+		     "1: la   %0,0\n"
+		     "2:\n"
+		     EX_TABLE(0b,2b) EX_TABLE(1b,2b)
+		     : "=d" (ret), "+d" (oldval), "=m" (*uaddr)
+		     : "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr)
+		     : "cc", "memory" );
+	*uval = oldval;
+	return ret;
+}
+
+int futex_atomic_cmpxchg_pt(u32 *uval, u32 __user *uaddr,
+			    u32 oldval, u32 newval)
+{
+	int ret;
+
+	if (segment_eq(get_fs(), KERNEL_DS))
+		return __futex_atomic_cmpxchg_pt(uval, uaddr, oldval, newval);
+	spin_lock(&current->mm->page_table_lock);
+	uaddr = (u32 __force __user *)
+		__dat_user_addr((__force unsigned long) uaddr);
+	if (!uaddr) {
+		spin_unlock(&current->mm->page_table_lock);
+		return -EFAULT;
+	}
+	get_page(virt_to_page(uaddr));
+	spin_unlock(&current->mm->page_table_lock);
+	ret = __futex_atomic_cmpxchg_pt(uval, uaddr, oldval, newval);
+	put_page(virt_to_page(uaddr));
+	return ret;
+}
+
+struct uaccess_ops uaccess_pt = {
+	.copy_from_user		= copy_from_user_pt,
+	.copy_from_user_small	= copy_from_user_pt,
+	.copy_to_user		= copy_to_user_pt,
+	.copy_to_user_small	= copy_to_user_pt,
+	.copy_in_user		= copy_in_user_pt,
+	.clear_user		= clear_user_pt,
+	.strnlen_user		= strnlen_user_pt,
+	.strncpy_from_user	= strncpy_from_user_pt,
+	.futex_atomic_op	= futex_atomic_op_pt,
+	.futex_atomic_cmpxchg	= futex_atomic_cmpxchg_pt,
+};