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authorLorenzo Stoakes <lstoakes@gmail.com>2016-12-14 15:06:55 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-12-14 16:04:09 -0800
commit8b7457ef9a9eb46cd1675d40d8e1fd3c47a38395 (patch)
tree485def76ab013b2609eb24762e4c39fc531c72d7
parent5b56d49fc31dbb0487e14ead790fc81ca9fb2c99 (diff)
downloadlinux-sh-8b7457ef9a9eb46cd1675d40d8e1fd3c47a38395.tar.gz
mm: unexport __get_user_pages_unlocked()
Unexport the low-level __get_user_pages_unlocked() function and replaces invocations with calls to more appropriate higher-level functions. In hva_to_pfn_slow() we are able to replace __get_user_pages_unlocked() with get_user_pages_unlocked() since we can now pass gup_flags. In async_pf_execute() and process_vm_rw_single_vec() we need to pass different tsk, mm arguments so get_user_pages_remote() is the sane replacement in these cases (having added manual acquisition and release of mmap_sem.) Additionally get_user_pages_remote() reintroduces use of the FOLL_TOUCH flag. However, this flag was originally silently dropped by commit 1e9877902dc7 ("mm/gup: Introduce get_user_pages_remote()"), so this appears to have been unintentional and reintroducing it is therefore not an issue. [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20161027095141.2569-3-lstoakes@gmail.com Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Jan Kara <jack@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krcmar <rkrcmar@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/mm.h3
-rw-r--r--mm/gup.c8
-rw-r--r--mm/nommu.c8
-rw-r--r--mm/process_vm_access.c12
-rw-r--r--virt/kvm/async_pf.c10
-rw-r--r--virt/kvm/kvm_main.c5
6 files changed, 25 insertions, 21 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h
index cc154454675a..7b2d14ed3815 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1280,9 +1280,6 @@ long get_user_pages(unsigned long start, unsigned long nr_pages,
struct vm_area_struct **vmas);
long get_user_pages_locked(unsigned long start, unsigned long nr_pages,
unsigned int gup_flags, struct page **pages, int *locked);
-long __get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm,
- unsigned long start, unsigned long nr_pages,
- struct page **pages, unsigned int gup_flags);
long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages,
struct page **pages, unsigned int gup_flags);
int get_user_pages_fast(unsigned long start, int nr_pages, int write,
diff --git a/mm/gup.c b/mm/gup.c
index b64c907aa4f0..55315555489d 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -865,9 +865,10 @@ EXPORT_SYMBOL(get_user_pages_locked);
* caller if required (just like with __get_user_pages). "FOLL_GET"
* is set implicitly if "pages" is non-NULL.
*/
-__always_inline long __get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm,
- unsigned long start, unsigned long nr_pages,
- struct page **pages, unsigned int gup_flags)
+static __always_inline long __get_user_pages_unlocked(struct task_struct *tsk,
+ struct mm_struct *mm, unsigned long start,
+ unsigned long nr_pages, struct page **pages,
+ unsigned int gup_flags)
{
long ret;
int locked = 1;
@@ -879,7 +880,6 @@ __always_inline long __get_user_pages_unlocked(struct task_struct *tsk, struct m
up_read(&mm->mmap_sem);
return ret;
}
-EXPORT_SYMBOL(__get_user_pages_unlocked);
/*
* get_user_pages_unlocked() is suitable to replace the form:
diff --git a/mm/nommu.c b/mm/nommu.c
index 9720e0bab029..c299a7fbca70 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -176,9 +176,10 @@ long get_user_pages_locked(unsigned long start, unsigned long nr_pages,
}
EXPORT_SYMBOL(get_user_pages_locked);
-long __get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm,
- unsigned long start, unsigned long nr_pages,
- struct page **pages, unsigned int gup_flags)
+static long __get_user_pages_unlocked(struct task_struct *tsk,
+ struct mm_struct *mm, unsigned long start,
+ unsigned long nr_pages, struct page **pages,
+ unsigned int gup_flags)
{
long ret;
down_read(&mm->mmap_sem);
@@ -187,7 +188,6 @@ long __get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm,
up_read(&mm->mmap_sem);
return ret;
}
-EXPORT_SYMBOL(__get_user_pages_unlocked);
long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages,
struct page **pages, unsigned int gup_flags)
diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c
index be8dc8d1edb9..84d0c7eada2b 100644
--- a/mm/process_vm_access.c
+++ b/mm/process_vm_access.c
@@ -88,7 +88,7 @@ static int process_vm_rw_single_vec(unsigned long addr,
ssize_t rc = 0;
unsigned long max_pages_per_loop = PVM_MAX_KMALLOC_PAGES
/ sizeof(struct pages *);
- unsigned int flags = FOLL_REMOTE;
+ unsigned int flags = 0;
/* Work out address and page range required */
if (len == 0)
@@ -100,15 +100,19 @@ static int process_vm_rw_single_vec(unsigned long addr,
while (!rc && nr_pages && iov_iter_count(iter)) {
int pages = min(nr_pages, max_pages_per_loop);
+ int locked = 1;
size_t bytes;
/*
* Get the pages we're interested in. We must
- * add FOLL_REMOTE because task/mm might not
+ * access remotely because task/mm might not
* current/current->mm
*/
- pages = __get_user_pages_unlocked(task, mm, pa, pages,
- process_pages, flags);
+ down_read(&mm->mmap_sem);
+ pages = get_user_pages_remote(task, mm, pa, pages, flags,
+ process_pages, NULL, &locked);
+ if (locked)
+ up_read(&mm->mmap_sem);
if (pages <= 0)
return -EFAULT;
diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c
index efeceb0a222d..3815e940fbea 100644
--- a/virt/kvm/async_pf.c
+++ b/virt/kvm/async_pf.c
@@ -76,16 +76,20 @@ static void async_pf_execute(struct work_struct *work)
struct kvm_vcpu *vcpu = apf->vcpu;
unsigned long addr = apf->addr;
gva_t gva = apf->gva;
+ int locked = 1;
might_sleep();
/*
* This work is run asynchromously to the task which owns
* mm and might be done in another context, so we must
- * use FOLL_REMOTE.
+ * access remotely.
*/
- __get_user_pages_unlocked(NULL, mm, addr, 1, NULL,
- FOLL_WRITE | FOLL_REMOTE);
+ down_read(&mm->mmap_sem);
+ get_user_pages_remote(NULL, mm, addr, 1, FOLL_WRITE, NULL, NULL,
+ &locked);
+ if (locked)
+ up_read(&mm->mmap_sem);
kvm_async_page_present_sync(vcpu, apf);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 823544c166be..de102cae7125 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1418,13 +1418,12 @@ static int hva_to_pfn_slow(unsigned long addr, bool *async, bool write_fault,
npages = get_user_page_nowait(addr, write_fault, page);
up_read(&current->mm->mmap_sem);
} else {
- unsigned int flags = FOLL_TOUCH | FOLL_HWPOISON;
+ unsigned int flags = FOLL_HWPOISON;
if (write_fault)
flags |= FOLL_WRITE;
- npages = __get_user_pages_unlocked(current, current->mm, addr, 1,
- page, flags);
+ npages = get_user_pages_unlocked(addr, 1, page, flags);
}
if (npages != 1)
return npages;