we do not call get_elf_info() in case of refiltering. Therefore, we will
not have any pt_load in that case, and so we get:
get_page_offset_x86_64: Can't get any pt_load to calculate page offset.
However, we will have vmcoreinfo and vmlinux information in case of
re-filtering. So, we are able to find kaslr offset and we can get
page_offset_base address. Thus we can read the page offset as well.
However, if kaslr is not enabled then use old method to find fixed page
offset.
Signed-off-by: Pratyush Anand <panand at redhat.com>
---
arch/x86_64.c | 22 ++++++++++++++++++++--
1 file changed, 20 insertions(+), 2 deletions(-)
diff --git a/arch/x86_64.c b/arch/x86_64.c
index ab5aae8f1b26..b38ba2479d3d 100644
--- a/arch/x86_64.c
+++ b/arch/x86_64.c
@@ -62,6 +62,7 @@ get_page_offset_x86_64(void)
int i;
unsigned long long phys_start;
unsigned long long virt_start;
+ unsigned long page_offset_base;
for (i = 0; get_pt_load(i, &phys_start, NULL, &virt_start, NULL); i++) {
if (virt_start < __START_KERNEL_map
@@ -71,8 +72,25 @@ get_page_offset_x86_64(void)
}
}
- ERRMSG("Can't get any pt_load to calculate page offset.\n");
- return FALSE;
+ if (!info->flag_refiltering) {
+ ERRMSG("Can't get any pt_load to calculate page offset.\n");
+ return FALSE;
+ }
+ if (info->kaslr_offset) {
+ page_offset_base = get_symbol_addr("page_offset_base");
+ page_offset_base += info->kaslr_offset;
+ if (!readmem(VADDR, page_offset_base, &info->page_offset,
+ sizeof(info->page_offset))) {
+ ERRMSG("Can't read page_offset_base.\n");
+ return FALSE;
+ }
+ } else if (info->kernel_version < KERNEL_VERSION(2, 6, 27)) {
+ info->page_offset = __PAGE_OFFSET_ORIG;
+ } else {
+ info->page_offset = __PAGE_OFFSET_2_6_27;
+ }
+
+ return TRUE;
}
int
--
2.9.3
