From: Hongyan Xia <hongyxia@amazon.com>
To: <xen-devel@lists.xenproject.org>
Cc: "Andrew Cooper" <andrew.cooper3@citrix.com>,
"Wei Liu" <wl@xen.org>, "Jan Beulich" <jbeulich@suse.com>,
"Roger Pau Monné" <roger.pau@citrix.com>
Subject: [Xen-devel] [PATCH v4 7/9] x86/mm: make sure there is one exit path for modify_xen_mappings
Date: Wed, 4 Dec 2019 17:10:59 +0000 [thread overview]
Message-ID: <8d396401c9cf40b8b593d2cf49b07f7bd5d422cf.1575477921.git.hongyxia@amazon.com> (raw)
In-Reply-To: <cover.1575477921.git.hongyxia@amazon.com>
From: Wei Liu <wei.liu2@citrix.com>
We will soon need to handle dynamically mapping / unmapping page
tables in the said function.
No functional change.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Hongyan Xia <hongyxia@amazon.com>
---
Changed since v3:
- remove asserts on rc since it never gets changed to anything else.
---
xen/arch/x86/mm.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index f530dd391c..4c659c28d8 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -5584,6 +5584,7 @@ int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int nf)
l1_pgentry_t *pl1e;
unsigned int i;
unsigned long v = s;
+ int rc = -ENOMEM;
/* Set of valid PTE bits which may be altered. */
#define FLAGS_MASK (_PAGE_NX|_PAGE_RW|_PAGE_PRESENT)
@@ -5627,7 +5628,8 @@ int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int nf)
/* PAGE1GB: shatter the superpage and fall through. */
l2t = alloc_xen_pagetable();
if ( !l2t )
- return -ENOMEM;
+ goto out;
+
for ( i = 0; i < L2_PAGETABLE_ENTRIES; i++ )
l2e_write(l2t + i,
l2e_from_pfn(l3e_get_pfn(*pl3e) +
@@ -5684,7 +5686,8 @@ int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int nf)
/* PSE: shatter the superpage and try again. */
l1t = alloc_xen_pagetable();
if ( !l1t )
- return -ENOMEM;
+ goto out;
+
for ( i = 0; i < L1_PAGETABLE_ENTRIES; i++ )
l1e_write(&l1t[i],
l1e_from_pfn(l2e_get_pfn(*pl2e) + i,
@@ -5817,7 +5820,10 @@ int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int nf)
flush_area(NULL, FLUSH_TLB_GLOBAL);
#undef FLAGS_MASK
- return 0;
+ rc = 0;
+
+ out:
+ return rc;
}
#undef flush_area
--
2.17.1
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next prev parent reply other threads:[~2019-12-04 17:11 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-04 17:10 [Xen-devel] [PATCH v4 0/9] Add alternative API for Xen PTEs Hongyan Xia
2019-12-04 17:10 ` [Xen-devel] [PATCH v4 1/9] x86: move some xen mm function declarations Hongyan Xia
2019-12-04 17:10 ` [Xen-devel] [PATCH v4 2/9] x86: introduce a new set of APIs to manage Xen page tables Hongyan Xia
2019-12-04 17:54 ` Xia, Hongyan
2019-12-05 7:20 ` Jan Beulich
2019-12-11 16:33 ` Julien Grall
2019-12-04 17:10 ` [Xen-devel] [PATCH v4 3/9] x86/mm: introduce l{1, 2}t local variables to map_pages_to_xen Hongyan Xia
2019-12-04 18:01 ` Xia, Hongyan
2019-12-05 8:38 ` Jan Beulich
2019-12-04 17:10 ` [Xen-devel] [PATCH v4 4/9] x86/mm: introduce l{1, 2}t local variables to modify_xen_mappings Hongyan Xia
2019-12-12 14:34 ` Julien Grall
2019-12-04 17:10 ` [Xen-devel] [PATCH v4 5/9] x86/mm: map_pages_to_xen would better have one exit path Hongyan Xia
2019-12-04 17:10 ` [Xen-devel] [PATCH v4 6/9] x86/mm: add an end_of_loop label in map_pages_to_xen Hongyan Xia
2019-12-05 10:21 ` Xia, Hongyan
2019-12-05 10:25 ` Jan Beulich
2019-12-05 11:02 ` Durrant, Paul
2019-12-05 11:12 ` Jan Beulich
2019-12-05 13:22 ` Xia, Hongyan
2019-12-06 15:58 ` Xia, Hongyan
2019-12-04 17:10 ` Hongyan Xia [this message]
2019-12-04 17:11 ` [Xen-devel] [PATCH v4 8/9] x86/mm: add an end_of_loop label in modify_xen_mappings Hongyan Xia
2019-12-04 17:11 ` [Xen-devel] [PATCH v4 9/9] x86/mm: change pl*e to l*t in virt_to_xen_l*e Hongyan Xia
2019-12-05 9:14 ` [Xen-devel] [PATCH v4 0/9] Add alternative API for Xen PTEs Jan Beulich
2019-12-05 9:41 ` Xia, Hongyan
2019-12-05 9:51 ` Jan Beulich
2019-12-05 10:45 ` Xia, Hongyan
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