arm64: deduce the start address of kernel code, based on kernel version

Resolves: bz2031738
Upstream: crash-utils
Conflict: None

Signed-off-by: Pingfan Liu <piliu@redhat.com>
This commit is contained in:
Pingfan Liu 2022-02-28 10:49:16 +08:00
parent b51cebe3ee
commit e7c201f56a
3 changed files with 107 additions and 0 deletions

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@ -0,0 +1,34 @@
From 6ecb8a23ca294de5ef92726c782f4c92fcb39d92 Mon Sep 17 00:00:00 2001
From: Huang Shijie <shijie@os.amperecomputing.com>
Date: Fri, 11 Feb 2022 09:46:42 +0000
Subject: [PATCH] arm64: Use CONFIG_ARM64_VA_BITS to initialize VA_BITS_ACTUAL
We can get VA_BITS_ACTUAL from CONFIG_ARM64_VA_BITS by guess.
Without this patch, we may need to use "--machdep vabits_actual=48" to
set the VA_BITS_ACTUAL.
Signed-off-by: Huang Shijie <shijie@os.amperecomputing.com>
---
arm64.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/arm64.c b/arm64.c
index 4f2c2b5..de1038a 100644
--- a/arm64.c
+++ b/arm64.c
@@ -4170,6 +4170,11 @@ arm64_calc_VA_BITS(void)
} else if (machdep->machspec->VA_BITS_ACTUAL) {
machdep->machspec->VA_BITS = machdep->machspec->VA_BITS_ACTUAL;
machdep->machspec->VA_START = _VA_START(machdep->machspec->VA_BITS_ACTUAL);
+ } else if (machdep->machspec->CONFIG_ARM64_VA_BITS) {
+ /* guess */
+ machdep->machspec->VA_BITS_ACTUAL = machdep->machspec->CONFIG_ARM64_VA_BITS;
+ machdep->machspec->VA_BITS = machdep->machspec->CONFIG_ARM64_VA_BITS;
+ machdep->machspec->VA_START = _VA_START(machdep->machspec->VA_BITS_ACTUAL);
} else
error(FATAL, "cannot determine VA_BITS_ACTUAL\n");
}
--
2.31.1

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@ -0,0 +1,69 @@
From e3bdc32aab5d8fe09b679cf394da8ba8826e207f Mon Sep 17 00:00:00 2001
From: Pingfan Liu <piliu@redhat.com>
Date: Thu, 24 Feb 2022 11:52:12 +0800
Subject: [PATCH] arm64: deduce the start address of kernel code, based on
kernel version
After kernel commit e2a073dde921 ("arm64: omit [_text, _stext) from
permanent kernel mapping"), the range [_text, _stext] is reclaimed. But
the current crash code still assumes kernel starting from "_text".
This change only affects the vmalloced area on arm64 and may result a
false in arm64_IS_VMALLOC_ADDR().
Since vmcore has no extra information about this trival change, it can
only be deduced from kernel version, which means ms->kimage_text can not
be correctly initialized until kernel_init() finishes. Here on arm64, it
can be done at the point machdep_init(POST_GDB). This is fine
since there is no access to vmalloced area at this stage.
Signed-off-by: Pingfan Liu <piliu@redhat.com>
---
arm64.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/arm64.c b/arm64.c
index de1038a..3ab8489 100644
--- a/arm64.c
+++ b/arm64.c
@@ -92,6 +92,20 @@ static void arm64_calc_VA_BITS(void);
static int arm64_is_uvaddr(ulong, struct task_context *);
static void arm64_calc_KERNELPACMASK(void);
+static void arm64_calc_kernel_start(void)
+{
+ struct machine_specific *ms = machdep->machspec;
+ struct syment *sp;
+
+ if (THIS_KERNEL_VERSION >= LINUX(5,11,0))
+ sp = kernel_symbol_search("_stext");
+ else
+ sp = kernel_symbol_search("_text");
+
+ ms->kimage_text = (sp ? sp->value : 0);
+ sp = kernel_symbol_search("_end");
+ ms->kimage_end = (sp ? sp->value : 0);
+}
/*
* Do all necessary machine-specific setup here. This is called several times
@@ -241,6 +255,7 @@ arm64_init(int when)
if (machdep->flags & NEW_VMEMMAP) {
struct syment *sp;
+ /* It is finally decided in arm64_calc_kernel_start() */
sp = kernel_symbol_search("_text");
ms->kimage_text = (sp ? sp->value : 0);
sp = kernel_symbol_search("_end");
@@ -387,6 +402,8 @@ arm64_init(int when)
break;
case POST_GDB:
+ /* Rely on kernel version to decide the kernel start address */
+ arm64_calc_kernel_start();
arm64_calc_virtual_memory_ranges();
arm64_get_section_size_bits();
--
2.31.1

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@ -34,6 +34,8 @@ Patch13: 0007-GDB-fix-completion-related-libstdc-assert.patch
Patch14: 0008-Improve-the-ps-performance-for-vmcores-with-large-nu.patch Patch14: 0008-Improve-the-ps-performance-for-vmcores-with-large-nu.patch
Patch15: 0009-arm64-Fix-segfault-by-bt-command-with-offline-cpus.patch Patch15: 0009-arm64-Fix-segfault-by-bt-command-with-offline-cpus.patch
Patch16: 0010-Fix-for-kmem-s-S-and-bt-F-F-on-Linux-5.17-rc1.patch Patch16: 0010-Fix-for-kmem-s-S-and-bt-F-F-on-Linux-5.17-rc1.patch
Patch17: 0001-arm64-Use-CONFIG_ARM64_VA_BITS-to-initialize-VA_BITS.patch
Patch18: 0001-arm64-deduce-the-start-address-of-kernel-code-based-.patch
%description %description
The core analysis suite is a self-contained tool that can be used to The core analysis suite is a self-contained tool that can be used to
@ -70,6 +72,8 @@ offered by Mission Critical Linux, or the LKCD kernel patch.
%patch14 -p1 %patch14 -p1
%patch15 -p1 %patch15 -p1
%patch16 -p1 %patch16 -p1
%patch17 -p1
%patch18 -p1
%build %build