[Crash-utility] [PATCH 3/4] kaslr: cleanup how to set values to the arguments of calc_kaslr_offset()
From: HATAYAMA Daisuke <d.hatayama(a)jp.fujitsu.com>
Setting values of the arguments of calc_kaslr_offset() should be done
at the end of the function. Currently, they are set in the middle
where their values could still be changed according to
get_kaslr_offset_from_vmcoreinfo(). This behavior will be problematic
in the later commits when we implement a trial-and-error approach
because the value of kaslr_offset could be passed to the outside of
calc_kaslr_offset() unexpectedly. Thus, fix this first.
---
kaslr_helper.c | 22 +++++++++++++---------
1 file changed, 13 insertions(+), 9 deletions(-)
diff --git a/kaslr_helper.c b/kaslr_helper.c
index fe5909c..acbb5c2 100644
--- a/kaslr_helper.c
+++ b/kaslr_helper.c
@@ -394,10 +394,11 @@ quit:
#define PTI_USER_PGTABLE_MASK (1 << PTI_USER_PGTABLE_BIT)
#define CR3_PCID_MASK 0xFFFull
int
-calc_kaslr_offset(ulong *kaslr_offset, ulong *phys_base)
+calc_kaslr_offset(ulong *ko, ulong *pb)
{
uint64_t cr3 = 0, idtr = 0, pgd = 0, idtr_paddr;
ulong divide_error_vmcore;
+ ulong kaslr_offset, phys_base;
ulong kaslr_offset_kdump, phys_base_kdump;
int ret = FALSE;
int verbose = CRASHDEBUG(1)? 1: 0;
@@ -445,9 +446,9 @@ calc_kaslr_offset(ulong *kaslr_offset, ulong *phys_base)
/* Now we can calculate kaslr_offset and phys_base */
divide_error_vmcore = get_vec0_addr(idtr_paddr);
- *kaslr_offset = divide_error_vmcore - st->divide_error_vmlinux;
- *phys_base = idtr_paddr -
- (st->idt_table_vmlinux + *kaslr_offset - __START_KERNEL_map);
+ kaslr_offset = divide_error_vmcore - st->divide_error_vmlinux;
+ phys_base = idtr_paddr -
+ (st->idt_table_vmlinux + kaslr_offset - __START_KERNEL_map);
if (CRASHDEBUG(1)) {
fprintf(fp, "calc_kaslr_offset: idtr=%lx\n", idtr);
@@ -465,9 +466,9 @@ calc_kaslr_offset(ulong *kaslr_offset, ulong *phys_base)
* from vmcoreinfo
*/
if (get_kaslr_offset_from_vmcoreinfo(
- *kaslr_offset, &kaslr_offset_kdump, &phys_base_kdump)) {
- *kaslr_offset = kaslr_offset_kdump;
- *phys_base = phys_base_kdump;
+ kaslr_offset, &kaslr_offset_kdump, &phys_base_kdump)) {
+ kaslr_offset = kaslr_offset_kdump;
+ phys_base = phys_base_kdump;
} else if (CRASHDEBUG(1)) {
fprintf(fp, "kaslr_helper: failed to determine which kernel was running at
crash,\n");
fprintf(fp, "kaslr_helper: asssuming the kdump 1st kernel.\n");
@@ -475,10 +476,13 @@ calc_kaslr_offset(ulong *kaslr_offset, ulong *phys_base)
if (CRASHDEBUG(1)) {
fprintf(fp, "calc_kaslr_offset: kaslr_offset=%lx\n",
- *kaslr_offset);
- fprintf(fp, "calc_kaslr_offset: phys_base=%lx\n", *phys_base);
+ kaslr_offset);
+ fprintf(fp, "calc_kaslr_offset: phys_base=%lx\n", phys_base);
}
+ *ko = kaslr_offset;
+ *pb = phys_base;
+
ret = TRUE;
quit:
vt->kernel_pgd[0] = 0;
--
1.8.3.1