From: Pavel Machek <pavel@ucw.cz>
Hi!
> > It makes swsusp behave correctly
> > w.r.t. discontingmem, and adds highmem handling
>
> Some of those ENOMEM panics in save_highmem_zone() look like they might
> need proper handling instead?
Done.
> The 256 byte automatic array in read_swapfiles() may bring you a visit from
> the stack space police, although I don't think it's really a problem. 256
> bytes for a pathname may be a bit excessive though.
Marked static, its only called once anyway.
> Please send me an update patch sometime which makes all the new code go
> away again if !CONFIG_HIGHMEM.
Done; plus I added some warnings to swsusp.S (based on discussion with
wli). Relative to previous diff, please apply.
---
25-akpm/arch/i386/power/swsusp.S | 9 +++++
25-akpm/kernel/power/swsusp.c | 59 +++++++++++++++++++++++++--------------
2 files changed, 46 insertions(+), 22 deletions(-)
diff -puN arch/i386/power/swsusp.S~swsusp-highmem-fixes arch/i386/power/swsusp.S
--- 25/arch/i386/power/swsusp.S~swsusp-highmem-fixes Tue Apr 6 15:36:23 2004
+++ 25-akpm/arch/i386/power/swsusp.S Tue Apr 6 15:36:23 2004
@@ -1,6 +1,13 @@
.text
-/* Originally gcc generated, modified by hand */
+/* Originally gcc generated, modified by hand
+ *
+ * This may not use any stack, nor any variable that is not "NoSave":
+ *
+ * Its rewriting one kernel image with another. What is stack in "old"
+ * image could very well be data page in "new" image, and overwriting
+ * your own stack under you is bad idea.
+ */
#include <linux/linkage.h>
#include <asm/segment.h>
diff -puN kernel/power/swsusp.c~swsusp-highmem-fixes kernel/power/swsusp.c
--- 25/kernel/power/swsusp.c~swsusp-highmem-fixes Tue Apr 6 15:36:23 2004
+++ 25-akpm/kernel/power/swsusp.c Tue Apr 6 15:36:23 2004
@@ -225,7 +225,7 @@ static void mark_swapfiles(swp_entry_t p
static void read_swapfiles(void) /* This is called before saving image */
{
int i, len;
- char buff[sizeof(resume_file)], *sname;
+ static char buff[sizeof(resume_file)], *sname;
len=strlen(resume_file);
root_swap = 0xFFFF;
@@ -366,6 +366,7 @@ static int write_suspend_image(void)
return 0;
}
+#ifdef CONFIG_HIGHMEM
struct highmem_page {
char *data;
struct page *page;
@@ -374,7 +375,7 @@ struct highmem_page {
struct highmem_page *highmem_copy = NULL;
-static void save_highmem_zone(struct zone *zone)
+static int save_highmem_zone(struct zone *zone)
{
unsigned long zone_pfn;
for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) {
@@ -384,7 +385,7 @@ static void save_highmem_zone(struct zon
unsigned long pfn = zone_pfn + zone->zone_start_pfn;
int chunk_size;
- if (!(pfn%200))
+ if (!(pfn%1000))
printk(".");
if (!pfn_valid(pfn))
continue;
@@ -397,7 +398,7 @@ static void save_highmem_zone(struct zon
*/
if (PageReserved(page)) {
printk("highmem reserved page?!\n");
- BUG();
+ continue;
}
if ((chunk_size = is_head_of_free_region(page))) {
pfn += chunk_size - 1;
@@ -406,26 +407,33 @@ static void save_highmem_zone(struct zon
}
save = kmalloc(sizeof(struct highmem_page), GFP_ATOMIC);
if (!save)
- panic("Not enough memory");
+ return -ENOMEM;
save->next = highmem_copy;
save->page = page;
save->data = (void *) get_zeroed_page(GFP_ATOMIC);
- if (!save->data)
- panic("Not enough memory");
+ if (!save->data) {
+ kfree(save);
+ return -ENOMEM;
+ }
kaddr = kmap_atomic(page, KM_USER0);
memcpy(save->data, kaddr, PAGE_SIZE);
kunmap_atomic(kaddr, KM_USER0);
highmem_copy = save;
}
+ return 0;
}
-static void save_highmem(void)
+static int save_highmem(void)
{
struct zone *zone;
+ int res = 0;
for_each_zone(zone) {
if (is_highmem(zone))
- save_highmem_zone(zone);
+ res = save_highmem_zone(zone);
+ if (res)
+ return res;
}
+ return 0;
}
static int restore_highmem(void)
@@ -443,6 +451,7 @@ static int restore_highmem(void)
}
return 0;
}
+#endif
static int pfn_is_nosave(unsigned long pfn)
{
@@ -460,7 +469,7 @@ static int count_and_copy_zone(struct zo
struct page *page;
unsigned long pfn = zone_pfn + zone->zone_start_pfn;
- if (!(pfn%200))
+ if (!(pfn%1000))
printk(".");
if (!pfn_valid(pfn))
continue;
@@ -548,7 +557,7 @@ static suspend_pagedir_t *create_suspend
while(nr_copy_pages--) {
p->address = get_zeroed_page(GFP_ATOMIC | __GFP_COLD);
- if(!p->address) {
+ if (!p->address) {
free_suspend_pagedir((unsigned long) pagedir);
return NULL;
}
@@ -589,10 +598,17 @@ static int suspend_prepare_image(void)
unsigned int nr_needed_pages = 0;
pagedir_nosave = NULL;
- printk( "/critical section: Handling highmem" );
- save_highmem();
+ printk( "/critical section: ");
+#ifdef CONFIG_HIGHMEM
+ printk( "handling highmem" );
+ if (save_highmem()) {
+ printk(KERN_CRIT "%sNot enough free pages for highmem\n", name_suspend);
+ return -ENOMEM;
+ }
+ printk(", ");
+#endif
- printk(", counting pages to copy" );
+ printk("counting pages to copy" );
drain_local_pages();
nr_copy_pages = count_and_copy_data_pages(NULL);
nr_needed_pages = nr_copy_pages + PAGES_FOR_IO;
@@ -602,23 +618,22 @@ static int suspend_prepare_image(void)
printk(KERN_CRIT "%sCouldn't get enough free pages, on %d pages short\n",
name_suspend, nr_needed_pages-nr_free_pages());
root_swap = 0xFFFF;
- return 1;
+ return -ENOMEM;
}
si_swapinfo(&i); /* FIXME: si_swapinfo(&i) returns all swap devices information.
We should only consider resume_device. */
if (i.freeswap < nr_needed_pages) {
printk(KERN_CRIT "%sThere's not enough swap space available, on %ld pages short\n",
name_suspend, nr_needed_pages-i.freeswap);
- return 1;
+ return -ENOSPC;
}
PRINTK( "Alloc pagedir\n" );
pagedir_save = pagedir_nosave = create_suspend_pagedir(nr_copy_pages);
- if(!pagedir_nosave) {
- /* Shouldn't happen */
- printk(KERN_CRIT "%sCouldn't allocate enough pages\n",name_suspend);
- panic("Really should not happen");
- return 1;
+ if (!pagedir_nosave) {
+ /* Pagedir is big, one-chunk allocation. It is easily possible for this allocation to fail */
+ printk(KERN_CRIT "%sCouldn't allocate continuous pagedir\n", name_suspend);
+ return -ENOMEM;
}
nr_copy_pages_check = nr_copy_pages;
pagedir_order_check = pagedir_order;
@@ -702,8 +717,10 @@ asmlinkage void do_magic_resume_2(void)
PRINTK( "Freeing prev allocated pagedir\n" );
free_suspend_pagedir((unsigned long) pagedir_save);
+#ifdef CONFIG_HIGHMEM
printk( "Restoring highmem\n" );
restore_highmem();
+#endif
printk("done, devices\n");
device_power_up();
_