mips-vdso-prefer-do_mmap-to-mmap_region.patch removed from -mm tree

The quilt patch titled
Subject: mips: vdso: prefer do_mmap() to mmap_region()
has been removed from the -mm tree. Its filename was
mips-vdso-prefer-do_mmap-to-mmap_region.patch

This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Lorenzo Stoakes <[email protected]>
Subject: mips: vdso: prefer do_mmap() to mmap_region()
Date: Thu, 2 Jan 2025 12:10:51 +0000

Patch series "mm: update mips to use do_mmap(), make mmap_region() internal".

Currently the only user of mmap_region() outside of the memory management code is the MIPS VDSO implementation.

This uses mmap_region() to map a 'delay slot emulation page' at the top of the stack which is read-only and executable.

This mapping requires that an already-acquired mmap write lock is utilised and that uffd and populate logic is ignored. This rules out vm_mmap(), however do_mmap() fits the bill.

Adapt this code to use do_mmap() and then once done, make mmap_region() internal and userland testable, and avoid any other uses of mmap_region(), which is absolutely and strictly an internal mm function which bypasses a great number of checks and logic.

This patch (of 2):

mmap_region() is an internal memory management implementation detail that is not intended to be used outside of the memory management subsystem.

Map the delay slot emulation page using do_mmap() which makes use of the already-held mmap write lock and bypasses unneeded populate and userfaultfd logic.

This should have the precise same behaviour as the existing logic.

---

 arch/mips/kernel/vdso.c |   10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

@@ -11,6 +11,7 @@
 #include <linux/ioport.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
+#include <linux/mman.h>
 #include <linux/random.h>
 #include <linux/sched.h>
 #include <linux/slab.h>

@@ -97,11 +98,12 @@ int arch_setup_additional_pages(struct l
 		return -EINTR;
 
 	if (IS_ENABLED(CONFIG_MIPS_FP_SUPPORT)) {
+		unsigned long unused;
+
 		/* Map delay slot emulation page */
-		base = mmap_region(NULL, STACK_TOP, PAGE_SIZE,
-				VM_READ | VM_EXEC |
-				VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
-				0, NULL);
+		base = do_mmap(NULL, STACK_TOP, PAGE_SIZE, PROT_READ | PROT_EXEC,
+			       MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, 0, 0, &unused,
+			       NULL);
 		if (IS_ERR_VALUE(base)) {
 			ret = base;
 			goto out;

_

Patches currently in -mm which might be from [email protected] are