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authorLinus Torvalds <torvalds@linux-foundation.org>2011-10-31 16:14:20 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-10-31 16:14:20 -0700
commit32087d4eeca14b82660dab288b1d659963b954bd (patch)
tree8c131ca9bf08f88d3b02e1937b795a42f8951d79 /arch/s390/mm/maccess.c
parentb1c907f3b2675ecb01e340948fc62d6535ff5ac3 (diff)
parent07ea815b22b9f70ec8de6ddf8db63a1dd1585caf (diff)
Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6
* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6: (54 commits) [S390] Remove error checking from copy_oldmem_page() [S390] qdio: prevent dsci access without adapter interrupts [S390] irqstats: split IPI interrupt accounting [S390] add missing __tlb_flush_global() for !CONFIG_SMP [S390] sparse: fix sparse symbol shadow warning [S390] sparse: fix sparse NULL pointer warnings [S390] sparse: fix sparse warnings with __user pointers [S390] sparse: fix sparse warnings in math-emu [S390] sparse: fix sparse warnings about missing prototypes [S390] sparse: fix sparse ANSI-C warnings [S390] sparse: fix sparse static warnings [S390] sparse: fix access past end of array warnings [S390] dasd: prevent path verification before resume [S390] qdio: remove multicast polling [S390] qdio: reset outbound SBAL error states [S390] qdio: EQBS retry after CCQ 96 [S390] qdio: add timestamp for last queue scan time [S390] Introduce get_clock_fast() [S390] kvm: Handle diagnose 0x10 (release pages) [S390] take mmap_sem when walking guest page table ...
Diffstat (limited to 'arch/s390/mm/maccess.c')
-rw-r--r--arch/s390/mm/maccess.c56
1 files changed, 56 insertions, 0 deletions
diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c
index 5dbbaa6e594..1cb8427bedf 100644
--- a/arch/s390/mm/maccess.c
+++ b/arch/s390/mm/maccess.c
@@ -11,6 +11,7 @@
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/errno.h>
+#include <linux/gfp.h>
#include <asm/system.h>
/*
@@ -60,6 +61,9 @@ long probe_kernel_write(void *dst, const void *src, size_t size)
return copied < 0 ? -EFAULT : 0;
}
+/*
+ * Copy memory in real mode (kernel to kernel)
+ */
int memcpy_real(void *dest, void *src, size_t count)
{
register unsigned long _dest asm("2") = (unsigned long) dest;
@@ -101,3 +105,55 @@ void copy_to_absolute_zero(void *dest, void *src, size_t count)
__ctl_load(cr0, 0, 0);
preempt_enable();
}
+
+/*
+ * Copy memory from kernel (real) to user (virtual)
+ */
+int copy_to_user_real(void __user *dest, void *src, size_t count)
+{
+ int offs = 0, size, rc;
+ char *buf;
+
+ buf = (char *) __get_free_page(GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+ rc = -EFAULT;
+ while (offs < count) {
+ size = min(PAGE_SIZE, count - offs);
+ if (memcpy_real(buf, src + offs, size))
+ goto out;
+ if (copy_to_user(dest + offs, buf, size))
+ goto out;
+ offs += size;
+ }
+ rc = 0;
+out:
+ free_page((unsigned long) buf);
+ return rc;
+}
+
+/*
+ * Copy memory from user (virtual) to kernel (real)
+ */
+int copy_from_user_real(void *dest, void __user *src, size_t count)
+{
+ int offs = 0, size, rc;
+ char *buf;
+
+ buf = (char *) __get_free_page(GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+ rc = -EFAULT;
+ while (offs < count) {
+ size = min(PAGE_SIZE, count - offs);
+ if (copy_from_user(buf, src + offs, size))
+ goto out;
+ if (memcpy_real(dest + offs, buf, size))
+ goto out;
+ offs += size;
+ }
+ rc = 0;
+out:
+ free_page((unsigned long) buf);
+ return rc;
+}