Commit-ID: e9d54cae8f03e7f963a12f44bd50d68f49b9ea36
Gitweb: http://git.kernel.org/tip/e9d54cae8f03e7f963a12f44bd50d68f49b9ea36
Author: Stuart Bennett <stuart@xxxxxxxxxxxxxxx>
AuthorDate: Fri, 30 Jan 2009 17:38:59 +0000
Commit: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Mon, 2 Mar 2009 10:20:35 +0100
x86 mmiotrace: WARN_ONCE if dis/arming a page fails
Print a full warning once, if arming or disarming a page fails.
Also, if initial arming fails, do not handle the page further. This
avoids the possibility of a page failing to arm and then later claiming
to have handled any fault on that page.
WARN_ONCE added by Pekka Paalanen.
Signed-off-by: Stuart Bennett <stuart@xxxxxxxxxxxxxxx>
Signed-off-by: Pekka Paalanen <pq@xxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
arch/x86/mm/kmmio.c | 25 +++++++++++++++++--------
1 files changed, 17 insertions(+), 8 deletions(-)
diff --git a/arch/x86/mm/kmmio.c b/arch/x86/mm/kmmio.c
index 93d8203..fb1f115 100644
--- a/arch/x86/mm/kmmio.c
+++ b/arch/x86/mm/kmmio.c
@@ -105,7 +105,7 @@ static struct kmmio_fault_page *get_kmmio_fault_page(unsigned long page)
return NULL;
}
-static void set_page_present(unsigned long addr, bool present,
+static int set_page_present(unsigned long addr, bool present,
unsigned int *pglevel)
{
pteval_t pteval;
@@ -116,7 +116,7 @@ static void set_page_present(unsigned long addr, bool present,
if (!pte) {
pr_err("kmmio: no pte for page 0x%08lx\n", addr);
- return;
+ return -1;
}
if (pglevel)
@@ -140,22 +140,27 @@ static void set_page_present(unsigned long addr, bool present,
default:
pr_err("kmmio: unexpected page level 0x%x.\n", level);
- return;
+ return -1;
}
__flush_tlb_one(addr);
+
+ return 0;
}
/** Mark the given page as not present. Access to it will trigger a fault. */
-static void arm_kmmio_fault_page(unsigned long page, unsigned int *pglevel)
+static int arm_kmmio_fault_page(unsigned long page, unsigned int *pglevel)
{
- set_page_present(page & PAGE_MASK, false, pglevel);
+ int ret = set_page_present(page & PAGE_MASK, false, pglevel);
+ WARN_ONCE(ret < 0, KERN_ERR "kmmio arming 0x%08lx failed.\n", page);
+ return ret;
}
/** Mark the given page as present. */
static void disarm_kmmio_fault_page(unsigned long page, unsigned int *pglevel)
{
- set_page_present(page & PAGE_MASK, true, pglevel);
+ int ret = set_page_present(page & PAGE_MASK, true, pglevel);
+ WARN_ONCE(ret < 0, KERN_ERR "kmmio disarming 0x%08lx failed.\n", page);
}
/*
@@ -326,9 +331,13 @@ static int add_kmmio_fault_page(unsigned long page)
f->count = 1;
f->page = page;
- list_add_rcu(&f->list, kmmio_page_list(f->page));
- arm_kmmio_fault_page(f->page, NULL);
+ if (arm_kmmio_fault_page(f->page, NULL)) {
+ kfree(f);
+ return -1;
+ }
+
+ list_add_rcu(&f->list, kmmio_page_list(f->page));
return 0;
}
--
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