openwrtv3/target/linux/brcm2708/patches-3.10/0108-vchiq-create_pagelist-copes-with-vmalloc-memory.patch

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From f3978e548747dfe988016ef7c99fe50975da90df Mon Sep 17 00:00:00 2001
From: Vincent Sanders <vincent.sanders@collabora.co.uk>
Date: Mon, 2 Sep 2013 16:44:57 +0100
Subject: [PATCH 108/196] vchiq: create_pagelist copes with vmalloc memory
Signed-off-by: Daniel Stone <daniels@collabora.com>
---
.../interface/vchiq_arm/vchiq_2835_arm.c | 83 ++++++++++++++--------
1 file changed, 53 insertions(+), 30 deletions(-)
diff --git a/drivers/misc/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c b/drivers/misc/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
index 2b5fa56..b3bdaa2 100644
--- a/drivers/misc/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
+++ b/drivers/misc/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
@@ -374,6 +374,7 @@ create_pagelist(char __user *buf, size_t count, unsigned short type,
unsigned int num_pages, offset, i;
char *addr, *base_addr, *next_addr;
int run, addridx, actual_pages;
+ unsigned long *need_release;
offset = (unsigned int)buf & (PAGE_SIZE - 1);
num_pages = (count + offset + PAGE_SIZE - 1) / PAGE_SIZE;
@@ -384,9 +385,10 @@ create_pagelist(char __user *buf, size_t count, unsigned short type,
** list
*/
pagelist = kmalloc(sizeof(PAGELIST_T) +
- (num_pages * sizeof(unsigned long)) +
- (num_pages * sizeof(pages[0])),
- GFP_KERNEL);
+ (num_pages * sizeof(unsigned long)) +
+ sizeof(unsigned long) +
+ (num_pages * sizeof(pages[0])),
+ GFP_KERNEL);
vchiq_log_trace(vchiq_arm_log_level,
"create_pagelist - %x", (unsigned int)pagelist);
@@ -394,28 +396,44 @@ create_pagelist(char __user *buf, size_t count, unsigned short type,
return -ENOMEM;
addrs = pagelist->addrs;
- pages = (struct page **)(addrs + num_pages);
+ need_release = (unsigned long *)(addrs + num_pages);
+ pages = (struct page **)(addrs + num_pages + 1);
- down_read(&task->mm->mmap_sem);
- actual_pages = get_user_pages(task, task->mm,
- (unsigned long)buf & ~(PAGE_SIZE - 1), num_pages,
- (type == PAGELIST_READ) /*Write */ , 0 /*Force */ ,
- pages, NULL /*vmas */);
- up_read(&task->mm->mmap_sem);
-
- if (actual_pages != num_pages)
- {
- /* This is probably due to the process being killed */
- while (actual_pages > 0)
- {
- actual_pages--;
- page_cache_release(pages[actual_pages]);
- }
- kfree(pagelist);
- if (actual_pages == 0)
- actual_pages = -ENOMEM;
- return actual_pages;
- }
+ if (is_vmalloc_addr(buf)) {
+ for (actual_pages = 0; actual_pages < num_pages; actual_pages++) {
+ pages[actual_pages] = vmalloc_to_page(buf + (actual_pages * PAGE_SIZE));
+ }
+ *need_release = 0; /* do not try and release vmalloc pages */
+ } else {
+ down_read(&task->mm->mmap_sem);
+ actual_pages = get_user_pages(task, task->mm,
+ (unsigned long)buf & ~(PAGE_SIZE - 1),
+ num_pages,
+ (type == PAGELIST_READ) /*Write */ ,
+ 0 /*Force */ ,
+ pages,
+ NULL /*vmas */);
+ up_read(&task->mm->mmap_sem);
+
+ if (actual_pages != num_pages) {
+ vchiq_log_info(vchiq_arm_log_level,
+ "create_pagelist - only %d/%d pages locked",
+ actual_pages,
+ num_pages);
+
+ /* This is probably due to the process being killed */
+ while (actual_pages > 0)
+ {
+ actual_pages--;
+ page_cache_release(pages[actual_pages]);
+ }
+ kfree(pagelist);
+ if (actual_pages == 0)
+ actual_pages = -ENOMEM;
+ return actual_pages;
+ }
+ *need_release = 1; /* release user pages */
+ }
pagelist->length = count;
pagelist->type = type;
@@ -482,6 +500,7 @@ create_pagelist(char __user *buf, size_t count, unsigned short type,
static void
free_pagelist(PAGELIST_T *pagelist, int actual)
{
+ unsigned long *need_release;
struct page **pages;
unsigned int num_pages, i;
@@ -492,7 +511,8 @@ free_pagelist(PAGELIST_T *pagelist, int actual)
(pagelist->length + pagelist->offset + PAGE_SIZE - 1) /
PAGE_SIZE;
- pages = (struct page **)(pagelist->addrs + num_pages);
+ need_release = (unsigned long *)(pagelist->addrs + num_pages);
+ pages = (struct page **)(pagelist->addrs + num_pages + 1);
/* Deal with any partial cache lines (fragments) */
if (pagelist->type >= PAGELIST_READ_WITH_FRAGMENTS) {
@@ -528,11 +548,14 @@ free_pagelist(PAGELIST_T *pagelist, int actual)
up(&g_free_fragments_sema);
}
- for (i = 0; i < num_pages; i++) {
- if (pagelist->type != PAGELIST_WRITE)
- set_page_dirty(pages[i]);
- page_cache_release(pages[i]);
- }
+ if (*need_release) {
+ for (i = 0; i < num_pages; i++) {
+ if (pagelist->type != PAGELIST_WRITE)
+ set_page_dirty(pages[i]);
+
+ page_cache_release(pages[i]);
+ }
+ }
kfree(pagelist);
}
--
1.9.1