[Crash-utility] [PATCH 2/2] crash-utility/arm64: assign page_offset with kernel configure value
On RHEL9, crash hits a bug when executing "crash /proc/kcore" :
seek error: kernel virtual address: ffff6a0f3fff0000 type: "pmd page"
The kernel virtual address does not vary with va_actual bits, instead,
is determined by configuration value. But crash does not observe this
fact.
Since this disagreement only happens if 52-bits kernel on 48 bits platform,
it can be handled only if "memstart_addr < 0".
Signed-off-by: Pingfan Liu <piliu(a)redhat.com>
Cc: HAGIO KAZUHITO <k-hagio-ab(a)nec.com>
Cc: Lianbo Jiang <lijiang(a)redhat.com>
Cc: Mark Salter <msalter(a)redhat.com>
Cc: Mark Langsdorf <mlangsdo(a)redhat.com>
Cc: Jeremy Linton <jlinton(a)redhat.com>
To: crash-utility(a)redhat.com
---
arm64.c | 10 +++++++++-
defs.h | 1 +
2 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/arm64.c b/arm64.c
index 132a39d..c2cd419 100644
--- a/arm64.c
+++ b/arm64.c
@@ -220,7 +220,15 @@ arm64_init(int when)
arm64_calc_VA_BITS();
arm64_calc_KERNELPACMASK();
ms = machdep->machspec;
- if (ms->VA_BITS_ACTUAL) {
+ /* For 52-bits kernel running on 48 bits platform */
+ if (ms->memstart_addr < 0) {
+ ms->page_offset = ARM64_FLIP_PAGE_OFFSET;
+ /* useless on arm64 */
+ machdep->identity_map_base = ARM64_FLIP_PAGE_OFFSET;
+ machdep->kvbase = ARM64_FLIP_PAGE_OFFSET;
+ ms->userspace_top = ARM64_USERSPACE_TOP_ACTUAL;
+ /* For 52-bits on 52-bits platform, or 48-bits on 48 */
+ } else if (ms->VA_BITS_ACTUAL) {
ms->page_offset = ARM64_FLIP_PAGE_OFFSET_ACTUAL;
machdep->identity_map_base = ARM64_FLIP_PAGE_OFFSET_ACTUAL;
machdep->kvbase = ARM64_FLIP_PAGE_OFFSET_ACTUAL;
diff --git a/defs.h b/defs.h
index d8e0f30..291db5d 100644
--- a/defs.h
+++ b/defs.h
@@ -3220,6 +3220,7 @@ typedef signed int s32;
#define ARM64_PAGE_OFFSET ((0xffffffffffffffffUL) \
<< (machdep->machspec->VA_BITS - 1))
/* after kernel commit 14c127c957c1 ("arm64: mm: Flip kernel VA space") */
+#define ARM64_FLIP_PAGE_OFFSET (-(1UL) <<
machdep->machspec->CONFIG_ARM64_VA_BITS)
#define ARM64_FLIP_PAGE_OFFSET_ACTUAL ((0xffffffffffffffffUL) \
- ((1UL) << machdep->machspec->VA_BITS_ACTUAL) + 1)
--
2.29.2