Commit Graph

8 Commits

Author SHA1 Message Date
Greg Kroah-Hartman
d9f7979c92 mm: no need to check return value of debugfs_create functions
When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Link: http://lkml.kernel.org/r/20190122152151.16139-14-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Laura Abbott <labbott@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-05 21:07:17 -08:00
Dan Carpenter
4b408c74ee mm/gup_benchmark.c: prevent integer overflow in ioctl
The concern here is that "gup->size" is a u64 and "nr_pages" is unsigned
long.  On 32 bit systems we could trick the kernel into allocating fewer
pages than expected.

Link: http://lkml.kernel.org/r/20181025061546.hnhkv33diogf2uis@kili.mountain
Fixes: 64c349f4ae ("mm: add infrastructure for get_user_pages_fast() benchmarking")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-31 08:54:12 -07:00
Keith Busch
714a3a1eba mm/gup_benchmark.c: add additional pinning methods
Provide new gup benchmark ioctl commands to run different user page
pinning methods, get_user_pages_longterm() and get_user_pages(), in
addition to the existing get_user_pages_fast().

Link: http://lkml.kernel.org/r/20181010195605.10689-2-keith.busch@intel.com
Signed-off-by: Keith Busch <keith.busch@intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-26 16:38:15 -07:00
Keith Busch
26db3d09d9 mm/gup_benchmark.c: time put_page()
We'd like to measure time to unpin user pages, so this adds a second
benchmark timer on put_page, separate from get_page.

Adding the field breaks this ioctl ABI, but should be okay since this an
in-tree kernel selftest.

[akpm@linux-foundation.org: add expansion to struct gup_benchmark for future use]
Link: http://lkml.kernel.org/r/20181010195605.10689-1-keith.busch@intel.com
Signed-off-by: Keith Busch <keith.busch@intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-26 16:38:15 -07:00
YueHaibing
5189686457 mm/gup_benchmark: fix unsigned comparison to zero in __gup_benchmark_ioctl
get_user_pages_fast() will return negative value if no pages were pinned,
then be converted to a unsigned, which is compared to zero, giving the
wrong result.

Link: http://lkml.kernel.org/r/20180921095015.26088-1-yuehaibing@huawei.com
Fixes: 09e35a4a1c ("mm/gup_benchmark: handle gup failures")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-05 16:32:04 -07:00
Kees Cook
778e1cdd81 treewide: kvzalloc() -> kvcalloc()
The kvzalloc() function has a 2-factor argument form, kvcalloc(). This
patch replaces cases of:

        kvzalloc(a * b, gfp)

with:
        kvcalloc(a * b, gfp)

as well as handling cases of:

        kvzalloc(a * b * c, gfp)

with:

        kvzalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

        kvcalloc(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

        kvzalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
  kvzalloc(
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  kvzalloc(
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
  kvzalloc(
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  kvzalloc(
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  kvzalloc(
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  kvzalloc(
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  kvzalloc(
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  kvzalloc(
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  kvzalloc(
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  kvzalloc(
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kvzalloc
+ kvcalloc
  (
-	sizeof(TYPE) * (COUNT_ID)
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kvzalloc
+ kvcalloc
  (
-	sizeof(TYPE) * COUNT_ID
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kvzalloc
+ kvcalloc
  (
-	sizeof(TYPE) * (COUNT_CONST)
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kvzalloc
+ kvcalloc
  (
-	sizeof(TYPE) * COUNT_CONST
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kvzalloc
+ kvcalloc
  (
-	sizeof(THING) * (COUNT_ID)
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kvzalloc
+ kvcalloc
  (
-	sizeof(THING) * COUNT_ID
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kvzalloc
+ kvcalloc
  (
-	sizeof(THING) * (COUNT_CONST)
+	COUNT_CONST, sizeof(THING)
  , ...)
|
- kvzalloc
+ kvcalloc
  (
-	sizeof(THING) * COUNT_CONST
+	COUNT_CONST, sizeof(THING)
  , ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kvzalloc
+ kvcalloc
  (
-	SIZE * COUNT
+	COUNT, SIZE
  , ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
  kvzalloc(
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kvzalloc(
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kvzalloc(
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kvzalloc(
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kvzalloc(
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kvzalloc(
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kvzalloc(
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kvzalloc(
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
  kvzalloc(
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kvzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kvzalloc(
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kvzalloc(
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kvzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  kvzalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
  kvzalloc(
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kvzalloc(
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kvzalloc(
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kvzalloc(
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kvzalloc(
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kvzalloc(
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kvzalloc(
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kvzalloc(
-	COUNT * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  kvzalloc(C1 * C2 * C3, ...)
|
  kvzalloc(
-	(E1) * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kvzalloc(
-	(E1) * (E2) * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kvzalloc(
-	(E1) * (E2) * (E3)
+	array3_size(E1, E2, E3)
  , ...)
|
  kvzalloc(
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
  kvzalloc(sizeof(THING) * C2, ...)
|
  kvzalloc(sizeof(TYPE) * C2, ...)
|
  kvzalloc(C1 * C2 * C3, ...)
|
  kvzalloc(C1 * C2, ...)
|
- kvzalloc
+ kvcalloc
  (
-	sizeof(TYPE) * (E2)
+	E2, sizeof(TYPE)
  , ...)
|
- kvzalloc
+ kvcalloc
  (
-	sizeof(TYPE) * E2
+	E2, sizeof(TYPE)
  , ...)
|
- kvzalloc
+ kvcalloc
  (
-	sizeof(THING) * (E2)
+	E2, sizeof(THING)
  , ...)
|
- kvzalloc
+ kvcalloc
  (
-	sizeof(THING) * E2
+	E2, sizeof(THING)
  , ...)
|
- kvzalloc
+ kvcalloc
  (
-	(E1) * E2
+	E1, E2
  , ...)
|
- kvzalloc
+ kvcalloc
  (
-	(E1) * (E2)
+	E1, E2
  , ...)
|
- kvzalloc
+ kvcalloc
  (
-	E1 * E2
+	E1, E2
  , ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12 16:19:22 -07:00
Michael S. Tsirkin
09e35a4a1c mm/gup_benchmark: handle gup failures
Patch series "mm/get_user_pages_fast fixes, cleanups", v2.

Turns out get_user_pages_fast and __get_user_pages_fast return different
values on error when given a single page: __get_user_pages_fast returns
0.  get_user_pages_fast returns either 0 or an error.

Callers of get_user_pages_fast expect an error so fix it up to return an
error consistently.

Stress the difference between get_user_pages_fast and
__get_user_pages_fast to make sure callers aren't confused.

This patch (of 3):

__gup_benchmark_ioctl does not handle the case where get_user_pages_fast
fails:

 - a negative return code will cause a buffer overrun

 - returning with partial success will cause use of uninitialized
   memory.

[akpm@linux-foundation.org: simplification]
Link: http://lkml.kernel.org/r/1522962072-182137-3-git-send-email-mst@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-13 17:10:27 -07:00
Kirill A. Shutemov
64c349f4ae mm: add infrastructure for get_user_pages_fast() benchmarking
Performance of get_user_pages_fast() is critical for some workloads, but
it's tricky to test it directly.

This patch provides /sys/kernel/debug/gup_benchmark that helps with
testing performance of it.

See tools/testing/selftests/vm/gup_benchmark.c for userspace
counterpart.

Link: http://lkml.kernel.org/r/20170908215603.9189-2-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17 16:10:04 -08:00