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| author | Stuart Bennett <stuart@freedesktop.org> | 2009-01-30 18:38:59 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-03-02 10:20:35 +0100 |
| commit | e9d54cae8f03e7f963a12f44bd50d68f49b9ea36 (patch) | |
| tree | be77d162ae2179f604de9cc6fbc5ab5c9d89b3fe /arch | |
| parent | x86: add far read test to testmmiotrace (diff) | |
| download | linux-e9d54cae8f03e7f963a12f44bd50d68f49b9ea36.tar.xz linux-e9d54cae8f03e7f963a12f44bd50d68f49b9ea36.zip | |
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@freedesktop.org>
Signed-off-by: Pekka Paalanen <pq@iki.fi>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch')
| -rw-r--r-- | 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 93d82038af4b..fb1f11546fcd 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; } |