3 files changed, 50 insertions, 2 deletions

diff --git a/arch/s390/kernel/compat_linux.c b/arch/s390/kernel/compat_linux.c
index 614056222875..18610cea03a2 100644
--- a/arch/s390/kernel/compat_linux.c
+++ b/arch/s390/kernel/compat_linux.c
@@ -58,6 +58,7 @@
 #include <linux/compat.h>
 #include <linux/vfs.h>
 #include <linux/ptrace.h>
+#include <linux/fadvise.h>
 
 #include <asm/types.h>
 #include <asm/ipc.h>
@@ -1043,3 +1044,40 @@ sys32_timer_create(clockid_t which_clock, struct compat_sigevent *se32,
 
         return ret;
 }
+
+/*
+ * 31 bit emulation wrapper functions for sys_fadvise64/fadvise64_64.
+ * These need to rewrite the advise values for POSIX_FADV_{DONTNEED,NOREUSE}
+ * because the 31 bit values differ from the 64 bit values.
+ */
+
+asmlinkage long
+sys32_fadvise64(int fd, loff_t offset, size_t len, int advise)
+{
+        if (advise == 4)
+                advise = POSIX_FADV_DONTNEED;
+        else if (advise == 5)
+                advise = POSIX_FADV_NOREUSE;
+        return sys_fadvise64(fd, offset, len, advise);
+}
+
+struct fadvise64_64_args {
+        int fd;
+        long long offset;
+        long long len;
+        int advice;
+};
+
+asmlinkage long
+sys32_fadvise64_64(struct fadvise64_64_args __user *args)
+{
+        struct fadvise64_64_args a;
+
+        if ( copy_from_user(&a, args, sizeof(a)) )
+                return -EFAULT;
+        if (a.advice == 4)
+                a.advice = POSIX_FADV_DONTNEED;
+        else if (a.advice == 5)
+                a.advice = POSIX_FADV_NOREUSE;
+        return sys_fadvise64_64(a.fd, a.offset, a.len, a.advice);
+}
diff --git a/arch/s390/kernel/compat_wrapper.S b/arch/s390/kernel/compat_wrapper.S
index bf529739c8ab..799a98eac92d 100644
--- a/arch/s390/kernel/compat_wrapper.S
+++ b/arch/s390/kernel/compat_wrapper.S
@@ -1251,12 +1251,12 @@ sys32_fadvise64_wrapper:
         or      %r3,%r4                 # get low word of 64bit loff_t
         llgfr   %r4,%r5                 # size_t (unsigned long)
         lgfr    %r5,%r6                 # int
-        jg      sys_fadvise64
+        jg      sys32_fadvise64
 
         .globl  sys32_fadvise64_64_wrapper
 sys32_fadvise64_64_wrapper:
         llgtr   %r2,%r2                 # struct fadvise64_64_args *
-        jg      s390_fadvise64_64
+        jg      sys32_fadvise64_64
 
         .globl  sys32_clock_settime_wrapper
 sys32_clock_settime_wrapper:
diff --git a/include/linux/fadvise.h b/include/linux/fadvise.h
index 6fc656dfb93d..e8e747139b9a 100644
--- a/include/linux/fadvise.h
+++ b/include/linux/fadvise.h
@@ -5,7 +5,17 @@
 #define POSIX_FADV_RANDOM       1 /* Expect random page references.  */
 #define POSIX_FADV_SEQUENTIAL   2 /* Expect sequential page references.  */
 #define POSIX_FADV_WILLNEED     3 /* Will need these pages.  */
+
+/*
+ * The advise values for POSIX_FADV_DONTNEED and POSIX_ADV_NOREUSE
+ * for s390-64 differ from the values for the rest of the world.
+ */
+#if defined(__s390x__)
+#define POSIX_FADV_DONTNEED     6 /* Don't need these pages.  */
+#define POSIX_FADV_NOREUSE      7 /* Data will be accessed once.  */
+#else
 #define POSIX_FADV_DONTNEED     4 /* Don't need these pages.  */
 #define POSIX_FADV_NOREUSE      5 /* Data will be accessed once.  */
+#endif
 
 #endif  /* FADVISE_H_INCLUDED */