File 0009-arm64-use-dedicated-bits-to-record-the-VA-space-layo.patch of Package crash
From bf1379a8b6ff8d6a8fa12978f7194f15f85c4380 Mon Sep 17 00:00:00 2001
From: Pingfan Liu <piliu@redhat.com>
Date: Fri, 2 Jul 2021 10:14:23 +0800
Subject: [PATCH] arm64: use dedicated bits to record the VA space layout
changes
arm64 memory layout experiences big changes due to the following kernel
commits in date descending order:
5. 7bc1a0f9e176 arm64: mm: use single quantity to represent the PA to VA translation
4. b6d00d47e81a arm64: mm: Introduce 52-bit Kernel VAs
3. 5383cc6efed1 arm64: mm: Introduce vabits_actual
2. 14c127c957c1 arm64: mm: Flip kernel VA space
1. f80fb3a3d508 arm64: add support for kernel ASLR
For 1, crash has already used NEW_VMEMMAP to trace it.
For 2, crash lacks a flag to tag it and handle it differently.
For 3, two important kernel variables vabits_actual and physvirt_offset
are introduced.
For 4, since it comes immediately after 3, crash-utility does not need
to distinguish it.
For 5, kernel variable phyvirt_offset is removed
These changes have effects on PTOV()/VTOP() formula. So introducing
two bits HAS_PHYSVIRT_OFFSET and FLIPPED_VM as hint to apply different
formula.
Signed-off-by: Pingfan Liu <piliu@redhat.com>
---
arm64.c | 10 ++++++++++
defs.h | 2 ++
2 files changed, 12 insertions(+)
diff --git a/arm64.c b/arm64.c
index 149db36..b04369f 100644
--- a/arm64.c
+++ b/arm64.c
@@ -563,6 +563,10 @@ arm64_dump_machdep_table(ulong arg)
fprintf(fp, "%sMACHDEP_BT_TEXT", others++ ? "|" : "");
if (machdep->flags & NEW_VMEMMAP)
fprintf(fp, "%sNEW_VMEMMAP", others++ ? "|" : "");
+ if (machdep->flags & FLIPPED_VM)
+ fprintf(fp, "%sFLIPPED_VM", others++ ? "|" : "");
+ if (machdep->flags & HAS_PHYSVIRT_OFFSET)
+ fprintf(fp, "%sHAS_PHYSVIRT_OFFSET", others++ ? "|" : "");
fprintf(fp, ")\n");
fprintf(fp, " kvbase: %lx\n", machdep->kvbase);
@@ -997,6 +1001,7 @@ arm64_calc_physvirt_offset(void)
if (READMEM(pc->mfd, &physvirt_offset, sizeof(physvirt_offset),
sp->value, sp->value -
machdep->machspec->kimage_voffset) > 0) {
+ machdep->flags |= HAS_PHYSVIRT_OFFSET;
ms->physvirt_offset = physvirt_offset;
}
}
@@ -3963,6 +3968,11 @@ arm64_calc_VA_BITS(void)
error(FATAL, "cannot determine VA_BITS_ACTUAL\n");
}
+ /*
+ * The mm flip commit is introduced before 52-bits VA, which is before the
+ * commit to export NUMBER(TCR_EL1_T1SZ)
+ */
+ machdep->flags |= FLIPPED_VM;
return;
}
diff --git a/defs.h b/defs.h
index b7b20af..eca145c 100644
--- a/defs.h
+++ b/defs.h
@@ -3214,6 +3214,8 @@ typedef signed int s32;
#define NEW_VMEMMAP (0x80)
#define VM_L4_4K (0x100)
#define UNW_4_14 (0x200)
+#define FLIPPED_VM (0x400)
+#define HAS_PHYSVIRT_OFFSET (0x800)
/*
* Get kimage_voffset from /dev/crash
--
2.33.1