Mailing List Archive

commit 289610483fc43e4082f0fc00c0ea8bca571b7ee5
Author: Penny Zheng <penny.zheng@arm.com>
AuthorDate: Wed Sep 22 16:18:30 2021 +0200
Commit: Jan Beulich <jbeulich@suse.com>
CommitDate: Wed Sep 22 16:18:30 2021 +0200

mm: fix broken tainted value in mark_page_free

Commit 540a637c3410780b519fc055f432afe271f642f8 defines a new
helper mark_page_free to extract common codes, while it accidently
breaks the local variable "tainted".

This patch fix it by letting mark_page_free() return bool of whether the
page is offlined and rename local variable "tainted" to "pg_offlined".

Coverity ID: 1491872
Fixes: 540a637c3410 ("xen: introduce mark_page_free")
Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
---
xen/common/page_alloc.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/xen/common/page_alloc.c b/xen/common/page_alloc.c
index 6142c7bb6a..5801358b4b 100644
--- a/xen/common/page_alloc.c
+++ b/xen/common/page_alloc.c
@@ -1380,8 +1380,10 @@ bool scrub_free_pages(void)
return node_to_scrub(false) != NUMA_NO_NODE;
}

-static void mark_page_free(struct page_info *pg, mfn_t mfn)
+static bool mark_page_free(struct page_info *pg, mfn_t mfn)
{
+ bool pg_offlined = false;
+
ASSERT(mfn_x(mfn) == mfn_x(page_to_mfn(pg)));

/*
@@ -1405,7 +1407,7 @@ static void mark_page_free(struct page_info *pg, mfn_t mfn)
case PGC_state_offlining:
pg->count_info = (pg->count_info & PGC_broken) |
PGC_state_offlined;
- tainted = 1;
+ pg_offlined = true;
break;

default:
@@ -1425,6 +1427,8 @@ static void mark_page_free(struct page_info *pg, mfn_t mfn)
/* This page is not a guest frame any more. */
page_set_owner(pg, NULL); /* set_gpfn_from_mfn snoops pg owner */
set_gpfn_from_mfn(mfn_x(mfn), INVALID_M2P_ENTRY);
+
+ return pg_offlined;
}

/* Free 2^@order set of pages. */
@@ -1433,7 +1437,7 @@ static void free_heap_pages(
{
unsigned long mask;
mfn_t mfn = page_to_mfn(pg);
- unsigned int i, node = phys_to_nid(mfn_to_maddr(mfn)), tainted = 0;
+ unsigned int i, node = phys_to_nid(mfn_to_maddr(mfn)), pg_offlined = 0;
unsigned int zone = page_to_zone(pg);

ASSERT(order <= MAX_ORDER);
@@ -1443,7 +1447,8 @@ static void free_heap_pages(

for ( i = 0; i < (1 << order); i++ )
{
- mark_page_free(&pg[i], mfn_add(mfn, i));
+ if ( mark_page_free(&pg[i], mfn_add(mfn, i)) )
+ pg_offlined = 1;

if ( need_scrub )
{
@@ -1517,7 +1522,7 @@ static void free_heap_pages(

page_list_add_scrub(pg, node, zone, order, pg->u.free.first_dirty);

- if ( tainted )
+ if ( pg_offlined )
reserve_offlined_page(pg);

spin_unlock(&heap_lock);
--
generated by git-patchbot for /home/xen/git/xen.git#staging