Kernel analysis utility for live systems, netdump, diskdump, kdump, LKCD or mcore dumpfiles
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From 5c4f786450ea61b87d4db0092288df83dd5cb454 Mon Sep 17 00:00:00 2001
From: Qi Zheng <zhengqi.arch@bytedance.com>
Date: Tue, 21 Dec 2021 15:40:31 +0800
Subject: [PATCH 01/11] Fix pvops Xen detection for arm machine
Since the xen_start_info on the arm/arm64 platform points to a static
variable '_xen_start_info'(see its definition as below), which makes
that the address of xen_start_info will never be null.
arch/arm/xen/enlighten.c:40:static struct start_info _xen_start_info;
arch/arm/xen/enlighten.c:41:struct start_info *xen_start_info = &_xen_start_info;
arch/arm/xen/enlighten.c:42:EXPORT_SYMBOL(xen_start_info);
As a result, the is_pvops_xen() in commit 4badc6229c69 ("Fix pvops
Xen detection for kernels >= v4.20") always returns TRUE because it
can always read out the non-null address of xen_start_info, finally
the following error will be reported on arm/arm64 platform(non-Xen
environment) because p2m_mid_missing and xen_p2m_addr are not defined:
crash: cannot resolve "p2m_top"
For the arm/arm64 platform, fix it by using xen_vcpu_info instead of
xen_start_info to detect Xen dumps.
In addition, also explicitly narrow the scope of the xen_start_info
check to x86 with the machine_type(), there is no need to check it on
other architectures.
Fixes: 4badc6229c69 ("Fix pvops Xen detection for kernels >= v4.20")
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Acked-by: Kazuhito Hagio <k-hagio-ab@nec.com>
Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
---
kernel.c | 20 +++++++++++++++-----
1 file changed, 15 insertions(+), 5 deletions(-)
diff --git a/kernel.c b/kernel.c
index 8ae9e0c169ff..a637dd0eb8f8 100644
--- a/kernel.c
+++ b/kernel.c
@@ -10754,11 +10754,21 @@ is_pvops_xen(void)
STREQ(sym, "paravirt_patch_default")))
return TRUE;
- if (symbol_exists("xen_start_info") &&
- readmem(symbol_value("xen_start_info"), KVADDR, &addr,
- sizeof(void *), "xen_start_info", RETURN_ON_ERROR) &&
- addr != 0)
- return TRUE;
+ if (machine_type("X86") || machine_type("X86_64")) {
+ if (symbol_exists("xen_start_info") &&
+ readmem(symbol_value("xen_start_info"), KVADDR, &addr,
+ sizeof(void *), "xen_start_info", RETURN_ON_ERROR) &&
+ addr != 0)
+ return TRUE;
+ }
+
+ if (machine_type("ARM") || machine_type("ARM64")) {
+ if (symbol_exists("xen_vcpu_info") &&
+ readmem(symbol_value("xen_vcpu_info"), KVADDR, &addr,
+ sizeof(void *), "xen_vcpu_info", RETURN_ON_ERROR) &&
+ addr != 0)
+ return TRUE;
+ }
return FALSE;
}
--
2.20.1