From: Ben Hutchings <ben@decadent.org.uk>
Date: Wed, 5 Jul 2017 12:32:43 +0000 (+0100)
Subject: mmap: Remember the MAP_FIXED flag as VM_FIXED
X-Git-Tag: archive/raspbian/4.15.17-1+rpi1^2~68
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=fa7349bab1a310c9a10bdc163f86b5884bd5106f;p=linux.git

mmap: Remember the MAP_FIXED flag as VM_FIXED

Since 4.15 there are no spare bits, but we can use VM_ARCH_1 as
VM_FIXED wil only be needed on x86.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

Gbp-Pq: Topic bugfix/x86
Gbp-Pq: Name mmap-remember-the-map_fixed-flag-as-vm_fixed.patch
---

diff --git a/include/linux/mm.h b/include/linux/mm.h
index fbd47990e71..432deb97aea 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -201,6 +201,11 @@ extern unsigned int kobjsize(const void *objp);
 #define VM_HUGETLB	0x00400000	/* Huge TLB Page VM */
 #define VM_SYNC		0x00800000	/* Synchronous page faults */
 #define VM_ARCH_1	0x01000000	/* Architecture-specific flag */
+#ifdef CONFIG_X86
+#define VM_FIXED	VM_ARCH_1	/* Allocated at fixed address */
+#else
+#define VM_FIXED	0
+#endif
 #define VM_WIPEONFORK	0x02000000	/* Wipe VMA contents in child. */
 #define VM_DONTDUMP	0x04000000	/* Do not include in the core dump */
 
diff --git a/include/linux/mman.h b/include/linux/mman.h
index 6a4d1caaff5..393970e55bb 100644
--- a/include/linux/mman.h
+++ b/include/linux/mman.h
@@ -131,7 +131,9 @@ calc_vm_flag_bits(unsigned long flags)
 	return _calc_vm_trans(flags, MAP_GROWSDOWN,  VM_GROWSDOWN ) |
 	       _calc_vm_trans(flags, MAP_DENYWRITE,  VM_DENYWRITE ) |
 	       _calc_vm_trans(flags, MAP_LOCKED,     VM_LOCKED    ) |
-	       _calc_vm_trans(flags, MAP_SYNC,	     VM_SYNC      );
+	       _calc_vm_trans(flags, MAP_SYNC,	     VM_SYNC      ) |
+	       (VM_FIXED ?
+		_calc_vm_trans(flags, MAP_FIXED,     VM_FIXED     ) : 0);
 }
 
 unsigned long vm_commit_limit(void);