66 lines
2.6 KiB
Diff
66 lines
2.6 KiB
Diff
|
From 1614959f2f0d79b5f7fdc57d6aa42da1a0298153 Mon Sep 17 00:00:00 2001
|
||
|
|
From: Pingfan Liu <piliu@redhat.com>
|
||
|
|
Date: Fri, 10 Dec 2021 10:57:33 +0800
|
||
|
|
Subject: [PATCH] arm64/crashdump: deduce paddr of _text based on kernel code
|
||
|
|
size
|
||
|
|
|
||
|
|
kexec-tools commit 61b8c79b0fb7 ("arm64/crashdump-arm64: deduce the
|
||
|
|
paddr of _text") tries to deduce the paddr of _text, but turns out
|
||
|
|
partially.
|
||
|
|
|
||
|
|
That commit is based on "The Image must be placed text_offset bytes from
|
||
|
|
a 2MB aligned base address anywhere in usable system RAM and called
|
||
|
|
there" in linux/Documentation/arm64/booting.rst, plus text_offset field
|
||
|
|
is zero.
|
||
|
|
|
||
|
|
But in practice, some boot loaders does not obey the convention, and
|
||
|
|
still boots up the kernel successfully.
|
||
|
|
|
||
|
|
Revisiting kernel commit e2a073dde921 ("arm64: omit [_text, _stext) from
|
||
|
|
permanent kernel mapping"), the kernel code size changes from (unsigned
|
||
|
|
long)__init_begin - (unsigned long)_text to (unsigned long)__init_begin
|
||
|
|
- (unsigned long)_stext
|
||
|
|
|
||
|
|
And it should be a better factor to decide which label starts the
|
||
|
|
"Kernel code" in /proc/iomem.
|
||
|
|
|
||
|
|
Signed-off-by: Pingfan Liu <piliu@redhat.com>
|
||
|
|
Signed-off-by: Simon Horman <horms@verge.net.au>
|
||
|
|
---
|
||
|
|
kexec/arch/arm64/crashdump-arm64.c | 14 +++++++++++---
|
||
|
|
1 file changed, 11 insertions(+), 3 deletions(-)
|
||
|
|
|
||
|
|
diff --git a/kexec/arch/arm64/crashdump-arm64.c b/kexec/arch/arm64/crashdump-arm64.c
|
||
|
|
index 03d6204..a02019a 100644
|
||
|
|
--- a/kexec/arch/arm64/crashdump-arm64.c
|
||
|
|
+++ b/kexec/arch/arm64/crashdump-arm64.c
|
||
|
|
@@ -91,14 +91,22 @@ static int iomem_range_callback(void *UNUSED(data), int UNUSED(nr),
|
||
|
|
return mem_regions_alloc_and_add(&system_memory_rgns,
|
||
|
|
base, length, RANGE_RAM);
|
||
|
|
else if (strncmp(str, KERNEL_CODE, strlen(KERNEL_CODE)) == 0) {
|
||
|
|
+
|
||
|
|
+ unsigned long long kva_text = get_kernel_sym("_text");
|
||
|
|
+ unsigned long long kva_stext = get_kernel_sym("_stext");
|
||
|
|
+ unsigned long long kva_text_end = get_kernel_sym("__init_begin");
|
||
|
|
+
|
||
|
|
/*
|
||
|
|
* old: kernel_code.start = __pa_symbol(_text);
|
||
|
|
* new: kernel_code.start = __pa_symbol(_stext);
|
||
|
|
*
|
||
|
|
- * By utilizing the fact that paddr(_text) should align on 2MB, plus
|
||
|
|
- * _stext - _text <= 64K.
|
||
|
|
+ * For compatibility, deduce by comparing the gap "__init_begin - _stext"
|
||
|
|
+ * and the res size of "Kernel code" in /proc/iomem
|
||
|
|
*/
|
||
|
|
- elf_info.kern_paddr_start = base & ((0xffffffffffffffffUL) << 21);
|
||
|
|
+ if (kva_text_end - kva_stext == length)
|
||
|
|
+ elf_info.kern_paddr_start = base - (kva_stext - kva_text);
|
||
|
|
+ else
|
||
|
|
+ elf_info.kern_paddr_start = base;
|
||
|
|
}
|
||
|
|
else if (strncmp(str, KERNEL_DATA, strlen(KERNEL_DATA)) == 0)
|
||
|
|
elf_info.kern_size = base + length - elf_info.kern_paddr_start;
|
||
|
|
--
|
||
|
|
1.8.3.1
|
||
|
|
|