| Message ID | 1475157221-21828-1-git-send-email-igor.druzhinin@citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
diff --git a/xen/common/trace.c b/xen/common/trace.c index f651cf3..a9563cc 100644 --- a/xen/common/trace.c +++ b/xen/common/trace.c @@ -149,7 +149,7 @@ static int calculate_tbuf_size(unsigned int pages, uint16_t t_info_first_offset) } t_info_words = num_online_cpus() * pages * sizeof(uint32_t); - t_info_pages = PFN_UP(t_info_first_offset + t_info_words); + t_info_pages = PFN_UP(t_info_first_offset * sizeof(uint32_t) + t_info_words); printk(XENLOG_INFO "xentrace: requesting %u t_info pages " "for %u trace pages on %u cpus\n", t_info_pages, pages, num_online_cpus());
As long as t_info_first_offset is calculated in uint32_t offsets we need to multiply it by sizeof(uint32_t) in order to get the right number of pages for trace metadata. Not doing that makes it impossible to read the trace buffer correctly from userspace for some corner cases. Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com> --- xen/common/trace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)