ARCv3: fix mmap

In 64-bit regime, glibc passes the actual offset in mmap, and not
the page index (due to historical size_t limitations).

core kernel mmap deals with page indexes only so need to convert
before calling core.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

Author: vineetgarc

arch/arc/include/uapi/asm/unistd.h

@@ -30,12 +30,6 @@
 #define __ARCH_WANT_STAT64
 #endif
 
-#ifdef __LP64__
-#define sys_mmap sys_mmap_pgoff
-#else
-#define sys_mmap2 sys_mmap_pgoff
-#endif
-
 #include <asm-generic/unistd.h>
 
 #define NR_syscalls	__NR_syscalls

arch/arc/kernel/sys.c

@@ -5,10 +5,33 @@
 #include <linux/unistd.h>
 
 #include <asm/syscalls.h>
+#include <asm/syscall.h>
 
 #define sys_clone	sys_clone_wrapper
 #define sys_clone3	sys_clone3_wrapper
 
+#ifdef CONFIG_64BIT
+SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
+		unsigned long, prot, unsigned long, flags,
+		unsigned long, fd, off_t, off)
+{
+	if (offset_in_page(off) != 0)
+		return -EINVAL;
+
+	return ksys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
+}
+#else
+SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
+	unsigned long, prot, unsigned long, flags,
+	unsigned long, fd, unsigned long, off)
+{
+	if (offset_in_page(off) != 0)
+		return -EINVAL;
+
+	return ksys_mmap_pgoff(addr, len, prot, flags, fd, off);
+}
+#endif
+
 #undef __SYSCALL
 #define __SYSCALL(nr, call) [nr] = (call),
 

arch/arc/mm/mmap.c

@@ -71,6 +71,8 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
 	info.low_limit = mm->mmap_base;
 	info.high_limit = TASK_SIZE;
 	info.align_mask = do_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
+#ifndef CONFIG_64BIT
 	info.align_offset = pgoff << PAGE_SHIFT;
+#endif
 	return vm_unmapped_area(&info);
 }