57 lines
2.0 KiB
Diff
57 lines
2.0 KiB
Diff
From 167d37e347fe35c6f7db826e8539e192c4375564 Mon Sep 17 00:00:00 2001
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From: Pingfan Liu <piliu@redhat.com>
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Date: Fri, 2 Jul 2021 10:14:22 +0800
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Subject: [PATCH 2/4] arm64: assign page_offset with VA_BITS kernel
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configuration value
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On RHEL9, crash hits a bug when executing "crash /proc/kcore":
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seek error: kernel virtual address: ffff6a0f3fff0000 type: "pmd page"
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The kernel virtual address does not vary with vabits_actual, instead,
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is determined by configuration value. But crash does not observe this
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fact.
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Since vabits_actual related kernel commit is introduced after arm64
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mm layout flip commit, so changes are safe under the condition if
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(ms->VA_BITS_ACTUAL), and keep the else branch untouched.
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Signed-off-by: Pingfan Liu <piliu@redhat.com>
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---
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arm64.c | 7 ++++---
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defs.h | 1 +
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2 files changed, 5 insertions(+), 3 deletions(-)
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diff --git a/arm64.c b/arm64.c
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index 9fe1a4a..149db36 100644
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--- a/arm64.c
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+++ b/arm64.c
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@@ -220,9 +220,10 @@ arm64_init(int when)
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/* vabits_actual introduced after mm flip, so it should be flipped layout */
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if (ms->VA_BITS_ACTUAL) {
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- ms->page_offset = ARM64_FLIP_PAGE_OFFSET_ACTUAL;
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- machdep->identity_map_base = ARM64_FLIP_PAGE_OFFSET_ACTUAL;
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- machdep->kvbase = ARM64_FLIP_PAGE_OFFSET_ACTUAL;
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+ ms->page_offset = ARM64_FLIP_PAGE_OFFSET;
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+ /* useless on arm64 */
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+ machdep->identity_map_base = ARM64_FLIP_PAGE_OFFSET;
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+ machdep->kvbase = ARM64_FLIP_PAGE_OFFSET;
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ms->userspace_top = ARM64_USERSPACE_TOP_ACTUAL;
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} else {
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ms->page_offset = ARM64_PAGE_OFFSET;
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diff --git a/defs.h b/defs.h
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index eb7ce6a..b7b20af 100644
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--- a/defs.h
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+++ b/defs.h
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@@ -3234,6 +3234,7 @@ typedef signed int s32;
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#define ARM64_PAGE_OFFSET ((0xffffffffffffffffUL) \
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<< (machdep->machspec->VA_BITS - 1))
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/* kernels >= v5.4 the kernel VA space is flipped */
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+#define ARM64_FLIP_PAGE_OFFSET (-(1UL) << machdep->machspec->CONFIG_ARM64_VA_BITS)
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#define ARM64_FLIP_PAGE_OFFSET_ACTUAL ((0xffffffffffffffffUL) \
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- ((1UL) << machdep->machspec->VA_BITS_ACTUAL) + 1)
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--
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2.29.2
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