A-Team_Digital_Solutions/android_kernel_motorola_sm6375
Watch
2
0
Fork
You've already forked android_kernel_motorola_sm6375
 0
mirror of https://github.com/BobTheBlinker/android_kernel_motorola_sm6375.git synced 2026-10-31 04:01:48 -04:00
Code Issues Projects Releases Packages Wiki Activity

userfaultfd: non-cooperative: add mremap() event

Browse source 
The event denotes that an area [start:end] moves to different location.
Length change isn't reported as "new" addresses, if they appear on the
uffd reader side they will not contain any data and the latter can just
zeromap them.

Waiting for the event ACK is also done outside of mmap sem, as for fork
event.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Pavel Emelyanov <[email protected]>
Signed-off-by: Mike Rapoport <[email protected]>
Signed-off-by: Andrea Arcangeli <[email protected]>
Cc: "Dr. David Alan Gilbert" <[email protected]>
Cc: Hillf Danton <[email protected]>
Cc: Michael Rapoport <[email protected]>
Cc: Mike Kravetz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Pavel Emelyanov 2017-02-22 15:42:34 -08:00 • committed by Linus Torvalds
commit 72f87654c6
4 changed files with 76 additions and 6 deletions
Download patch file Download diff file Expand all files Collapse all files

17
mm/mremap.c
View file

@ -22,6 +22,7 @@
#include <linux/mmu_notifier.h>
#include <linux/uaccess.h>
#include <linux/mm-arch-hooks.h>
#include <linux/userfaultfd_k.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
@ -250,7 +251,8 @@ unsigned long move_page_tables(struct vm_area_struct *vma,
static unsigned long move_vma(struct vm_area_struct *vma,
unsigned long old_addr, unsigned long old_len,
unsigned long new_len, unsigned long new_addr, bool *locked)
unsigned long new_len, unsigned long new_addr,
bool *locked, struct vm_userfaultfd_ctx *uf)
{
struct mm_struct *mm = vma->vm_mm;
struct vm_area_struct *new_vma;
@ -309,6 +311,7 @@ static unsigned long move_vma(struct vm_area_struct *vma,
old_addr = new_addr;
new_addr = err;
} else {
mremap_userfaultfd_prep(new_vma, uf);
arch_remap(mm, old_addr, old_addr + old_len,
new_addr, new_addr + new_len);
}
@ -413,7 +416,8 @@ static struct vm_area_struct *vma_to_resize(unsigned long addr,
}
static unsigned long mremap_to(unsigned long addr, unsigned long old_len,
unsigned long new_addr, unsigned long new_len, bool *locked)
unsigned long new_addr, unsigned long new_len, bool *locked,
struct vm_userfaultfd_ctx *uf)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
@ -458,7 +462,7 @@ static unsigned long mremap_to(unsigned long addr, unsigned long old_len,
if (offset_in_page(ret))
goto out1;
ret = move_vma(vma, addr, old_len, new_len, new_addr, locked);
ret = move_vma(vma, addr, old_len, new_len, new_addr, locked, uf);
if (!(offset_in_page(ret)))
goto out;
out1:
@ -497,6 +501,7 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
unsigned long ret = -EINVAL;
unsigned long charged = 0;
bool locked = false;
struct vm_userfaultfd_ctx uf = NULL_VM_UFFD_CTX;
if (flags & ~(MREMAP_FIXED | MREMAP_MAYMOVE))
return ret;
@ -523,7 +528,7 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
if (flags & MREMAP_FIXED) {
ret = mremap_to(addr, old_len, new_addr, new_len,
&locked);
&locked, &uf);
goto out;
}
@ -592,7 +597,8 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
goto out;
}
ret = move_vma(vma, addr, old_len, new_len, new_addr, &locked);
ret = move_vma(vma, addr, old_len, new_len, new_addr,
&locked, &uf);
}
out:
if (offset_in_page(ret)) {
@ -602,5 +608,6 @@ out:
up_write(&current->mm->mmap_sem);
if (locked && new_len > old_len)
mm_populate(new_addr + old_len, new_len - old_len);
mremap_userfaultfd_complete(uf, addr, new_addr, old_len);
return ret;
}