linux/net/rds/info.c
Kees Cook 6da2ec5605 treewide: kmalloc() -> kmalloc_array()
The kmalloc() function has a 2-factor argument form, kmalloc_array(). This
patch replaces cases of:

        kmalloc(a * b, gfp)

with:
        kmalloc_array(a * b, gfp)

as well as handling cases of:

        kmalloc(a * b * c, gfp)

with:

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

as it's slightly less ugly than:

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

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

        kmalloc(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 tools/ directory was manually excluded, since it has its own
implementation of kmalloc().

The Coccinelle script used for this was:

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

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

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

(
  kmalloc(
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  kmalloc(
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  kmalloc(
-	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;
@@

(
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * (COUNT_ID)
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * COUNT_ID
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * (COUNT_CONST)
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(TYPE) * COUNT_CONST
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * (COUNT_ID)
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * COUNT_ID
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * (COUNT_CONST)
+	COUNT_CONST, sizeof(THING)
  , ...)
|
- kmalloc
+ kmalloc_array
  (
-	sizeof(THING) * COUNT_CONST
+	COUNT_CONST, sizeof(THING)
  , ...)
)

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

- kmalloc
+ kmalloc_array
  (
-	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;
@@

(
  kmalloc(
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kmalloc(
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kmalloc(
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kmalloc(
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kmalloc(
-	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;
@@

(
  kmalloc(
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kmalloc(
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kmalloc(
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  kmalloc(
-	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;
@@

(
  kmalloc(
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kmalloc(
-	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;
@@

(
  kmalloc(C1 * C2 * C3, ...)
|
  kmalloc(
-	(E1) * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kmalloc(
-	(E1) * (E2) * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kmalloc(
-	(E1) * (E2) * (E3)
+	array3_size(E1, E2, E3)
  , ...)
|
  kmalloc(
-	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;
@@

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

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12 16:19:22 -07:00

244 lines
6.4 KiB
C

/*
* Copyright (c) 2006 Oracle. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
*/
#include <linux/percpu.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/proc_fs.h>
#include <linux/export.h>
#include "rds.h"
/*
* This file implements a getsockopt() call which copies a set of fixed
* sized structs into a user-specified buffer as a means of providing
* read-only information about RDS.
*
* For a given information source there are a given number of fixed sized
* structs at a given time. The structs are only copied if the user-specified
* buffer is big enough. The destination pages that make up the buffer
* are pinned for the duration of the copy.
*
* This gives us the following benefits:
*
* - simple implementation, no copy "position" across multiple calls
* - consistent snapshot of an info source
* - atomic copy works well with whatever locking info source has
* - one portable tool to get rds info across implementations
* - long-lived tool can get info without allocating
*
* at the following costs:
*
* - info source copy must be pinned, may be "large"
*/
struct rds_info_iterator {
struct page **pages;
void *addr;
unsigned long offset;
};
static DEFINE_SPINLOCK(rds_info_lock);
static rds_info_func rds_info_funcs[RDS_INFO_LAST - RDS_INFO_FIRST + 1];
void rds_info_register_func(int optname, rds_info_func func)
{
int offset = optname - RDS_INFO_FIRST;
BUG_ON(optname < RDS_INFO_FIRST || optname > RDS_INFO_LAST);
spin_lock(&rds_info_lock);
BUG_ON(rds_info_funcs[offset]);
rds_info_funcs[offset] = func;
spin_unlock(&rds_info_lock);
}
EXPORT_SYMBOL_GPL(rds_info_register_func);
void rds_info_deregister_func(int optname, rds_info_func func)
{
int offset = optname - RDS_INFO_FIRST;
BUG_ON(optname < RDS_INFO_FIRST || optname > RDS_INFO_LAST);
spin_lock(&rds_info_lock);
BUG_ON(rds_info_funcs[offset] != func);
rds_info_funcs[offset] = NULL;
spin_unlock(&rds_info_lock);
}
EXPORT_SYMBOL_GPL(rds_info_deregister_func);
/*
* Typically we hold an atomic kmap across multiple rds_info_copy() calls
* because the kmap is so expensive. This must be called before using blocking
* operations while holding the mapping and as the iterator is torn down.
*/
void rds_info_iter_unmap(struct rds_info_iterator *iter)
{
if (iter->addr) {
kunmap_atomic(iter->addr);
iter->addr = NULL;
}
}
/*
* get_user_pages() called flush_dcache_page() on the pages for us.
*/
void rds_info_copy(struct rds_info_iterator *iter, void *data,
unsigned long bytes)
{
unsigned long this;
while (bytes) {
if (!iter->addr)
iter->addr = kmap_atomic(*iter->pages);
this = min(bytes, PAGE_SIZE - iter->offset);
rdsdebug("page %p addr %p offset %lu this %lu data %p "
"bytes %lu\n", *iter->pages, iter->addr,
iter->offset, this, data, bytes);
memcpy(iter->addr + iter->offset, data, this);
data += this;
bytes -= this;
iter->offset += this;
if (iter->offset == PAGE_SIZE) {
kunmap_atomic(iter->addr);
iter->addr = NULL;
iter->offset = 0;
iter->pages++;
}
}
}
EXPORT_SYMBOL_GPL(rds_info_copy);
/*
* @optval points to the userspace buffer that the information snapshot
* will be copied into.
*
* @optlen on input is the size of the buffer in userspace. @optlen
* on output is the size of the requested snapshot in bytes.
*
* This function returns -errno if there is a failure, particularly -ENOSPC
* if the given userspace buffer was not large enough to fit the snapshot.
* On success it returns the positive number of bytes of each array element
* in the snapshot.
*/
int rds_info_getsockopt(struct socket *sock, int optname, char __user *optval,
int __user *optlen)
{
struct rds_info_iterator iter;
struct rds_info_lengths lens;
unsigned long nr_pages = 0;
unsigned long start;
unsigned long i;
rds_info_func func;
struct page **pages = NULL;
int ret;
int len;
int total;
if (get_user(len, optlen)) {
ret = -EFAULT;
goto out;
}
/* check for all kinds of wrapping and the like */
start = (unsigned long)optval;
if (len < 0 || len > INT_MAX - PAGE_SIZE + 1 || start + len < start) {
ret = -EINVAL;
goto out;
}
/* a 0 len call is just trying to probe its length */
if (len == 0)
goto call_func;
nr_pages = (PAGE_ALIGN(start + len) - (start & PAGE_MASK))
>> PAGE_SHIFT;
pages = kmalloc_array(nr_pages, sizeof(struct page *), GFP_KERNEL);
if (!pages) {
ret = -ENOMEM;
goto out;
}
ret = get_user_pages_fast(start, nr_pages, 1, pages);
if (ret != nr_pages) {
if (ret > 0)
nr_pages = ret;
else
nr_pages = 0;
ret = -EAGAIN; /* XXX ? */
goto out;
}
rdsdebug("len %d nr_pages %lu\n", len, nr_pages);
call_func:
func = rds_info_funcs[optname - RDS_INFO_FIRST];
if (!func) {
ret = -ENOPROTOOPT;
goto out;
}
iter.pages = pages;
iter.addr = NULL;
iter.offset = start & (PAGE_SIZE - 1);
func(sock, len, &iter, &lens);
BUG_ON(lens.each == 0);
total = lens.nr * lens.each;
rds_info_iter_unmap(&iter);
if (total > len) {
len = total;
ret = -ENOSPC;
} else {
len = total;
ret = lens.each;
}
if (put_user(len, optlen))
ret = -EFAULT;
out:
for (i = 0; pages && i < nr_pages; i++)
put_page(pages[i]);
kfree(pages);
return ret;
}