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kcore: register vmemmap range 

Benjamin Herrenschmidt <benh@kernel.crashing.org> pointed out that vmemmap
range is not included in KCORE_RAM, KCORE_VMALLOC ....

This adds KCORE_VMEMMAP if SPARSEMEM_VMEMMAP is used.  By this, vmemmap
can be readable via /proc/kcore

Because it's not vmalloc area, vread/vwrite cannot be used.  But the range
is static against the memory layout, this patch handles vmemmap area by
the same scheme with physical memory.

This patch assumes SPARSEMEM_VMEMMAP range is not in VMALLOC range.  It's
correct now.

[akpm@linux-foundation.org: fix typo]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
hifive-unleashed-5.1
KAMEZAWA Hiroyuki 2009-09-22 16:45:49 -07:00 committed by Linus Torvalds
parent 3089aa1b0c
commit 26562c59fa
2 changed files with 51 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

52
fs/proc/kcore.c
View File

@ -103,7 +103,7 @@ static void free_kclist_ents(struct list_head *head)
}
}
/*
* Replace all KCORE_RAM information with passed list.
* Replace all KCORE_RAM/KCORE_VMEMMAP information with passed list.
*/
static void __kcore_update_ram(struct list_head *list)
{
@ -113,7 +113,8 @@ static void __kcore_update_ram(struct list_head *list)
write_lock(&kclist_lock);
if (kcore_need_update) {
list_for_each_entry_safe(pos, tmp, &kclist_head, list) {
if (pos->type == KCORE_RAM)
if (pos->type == KCORE_RAM
|| pos->type == KCORE_VMEMMAP)
list_move(&pos->list, &garbage);
}
list_splice_tail(list, &kclist_head);
@ -151,6 +152,47 @@ static int kcore_update_ram(void)
#else /* !CONFIG_HIGHMEM */
#ifdef CONFIG_SPARSEMEM_VMEMMAP
/* calculate vmemmap's address from given system ram pfn and register it */
int get_sparsemem_vmemmap_info(struct kcore_list *ent, struct list_head *head)
{
unsigned long pfn = __pa(ent->addr) >> PAGE_SHIFT;
unsigned long nr_pages = ent->size >> PAGE_SHIFT;
unsigned long start, end;
struct kcore_list *vmm, *tmp;
start = ((unsigned long)pfn_to_page(pfn)) & PAGE_MASK;
end = ((unsigned long)pfn_to_page(pfn + nr_pages)) - 1;
end = ALIGN(end, PAGE_SIZE);
/* overlap check (because we have to align page */
list_for_each_entry(tmp, head, list) {
if (tmp->type != KCORE_VMEMMAP)
continue;
if (start < tmp->addr + tmp->size)
if (end > tmp->addr)
end = tmp->addr;
}
if (start < end) {
vmm = kmalloc(sizeof(*vmm), GFP_KERNEL);
if (!vmm)
return 0;
vmm->addr = start;
vmm->size = end - start;
vmm->type = KCORE_VMEMMAP;
list_add_tail(&vmm->list, head);
}
return 1;
}
#else
int get_sparsemem_vmemmap_info(struct kcore_list *ent, struct list_head *head)
{
return 1;
}
#endif
static int
kclist_add_private(unsigned long pfn, unsigned long nr_pages, void *arg)
{
@ -181,6 +223,12 @@ kclist_add_private(unsigned long pfn, unsigned long nr_pages, void *arg)
ent->type = KCORE_RAM;
list_add_tail(&ent->list, head);
if (!get_sparsemem_vmemmap_info(ent, head)) {
list_del(&ent->list);
goto free_out;
}
return 0;
free_out:
kfree(ent);

1
include/linux/proc_fs.h
View File

@ -82,6 +82,7 @@ enum kcore_type {
KCORE_TEXT,
KCORE_VMALLOC,
KCORE_RAM,
KCORE_VMEMMAP,
KCORE_OTHER,
};