800917b5a2
- Update to Xen 4.1.2_rc2 c/s 23152 - bnc#716695 - domUs using tap devices will not start updated multi-xvdp.patch - Upstream patches from Jan 23803-intel-pmu-models.patch 23800-x86_64-guest-addr-range.patch 23795-intel-ich10-quirk.patch 23804-x86-IPI-counts.patch - bnc#706106 - Inconsistent reporting of VM names during migration xend-migration-domname-fix.patch - bnc#712823 - L3:Xen guest does not start reliable when rebooted xend-vcpu-affinity-fix.patch OBS-URL: https://build.opensuse.org/package/show/Virtualization/xen?expand=0&rev=143
66 lines
2.2 KiB
Diff
66 lines
2.2 KiB
Diff
xentrace: correct overflow check for number of per-cpu trace pages
|
|
|
|
(xen-unstable changeset 23239:51d89366c859)
|
|
|
|
The calculated number of per-cpu trace pages is stored in t_info and
|
|
shared with tools like xentrace. Since its an u16 the value may overflow
|
|
because the current check is based on u32.
|
|
Using the u16 means each cpu could in theory use up to 256MB as trace
|
|
buffer. However such a large allocation will currently fail on x86 due
|
|
to the MAX_ORDER limit.
|
|
Check both max theoretical number of pages per cpu and max number of
|
|
pages reachable by struct t_buf->prod/cons variables with requested
|
|
number of pages.
|
|
|
|
Signed-off-by: Olaf Hering <olaf@aepfle.de>
|
|
|
|
---
|
|
xen/common/trace.c | 22 +++++++++++++++-------
|
|
1 file changed, 15 insertions(+), 7 deletions(-)
|
|
|
|
Index: xen-4.1.2-testing/xen/common/trace.c
|
|
===================================================================
|
|
--- xen-4.1.2-testing.orig/xen/common/trace.c
|
|
+++ xen-4.1.2-testing/xen/common/trace.c
|
|
@@ -105,25 +105,33 @@ static void calc_tinfo_first_offset(void
|
|
* calculate_tbuf_size - check to make sure that the proposed size will fit
|
|
* in the currently sized struct t_info and allows prod and cons to
|
|
* reach double the value without overflow.
|
|
+ * The t_info layout is fixed and cant be changed without breaking xentrace.
|
|
* Initialize t_info_pages based on number of trace pages.
|
|
*/
|
|
static int calculate_tbuf_size(unsigned int pages)
|
|
{
|
|
- struct t_buf dummy;
|
|
- typeof(dummy.prod) size;
|
|
+ struct t_buf dummy_size;
|
|
+ typeof(dummy_size.prod) max_size;
|
|
+ struct t_info dummy_pages;
|
|
+ typeof(dummy_pages.tbuf_size) max_pages;
|
|
unsigned int t_info_words;
|
|
|
|
/* force maximum value for an unsigned type */
|
|
- size = -1;
|
|
+ max_size = -1;
|
|
+ max_pages = -1;
|
|
|
|
/* max size holds up to n pages */
|
|
- size /= PAGE_SIZE;
|
|
- if ( pages > size )
|
|
+ max_size /= PAGE_SIZE;
|
|
+
|
|
+ if ( max_size < max_pages )
|
|
+ max_pages = max_size;
|
|
+
|
|
+ if ( pages > max_pages )
|
|
{
|
|
printk(XENLOG_INFO "xentrace: requested number of %u pages "
|
|
"reduced to %u\n",
|
|
- pages, (unsigned int)size);
|
|
- pages = size;
|
|
+ pages, max_pages);
|
|
+ pages = max_pages;
|
|
}
|
|
|
|
t_info_words = num_online_cpus() * pages * sizeof(uint32_t);
|