From 5c4f786450ea61b87d4db0092288df83dd5cb454 Mon Sep 17 00:00:00 2001 From: Qi Zheng 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 Acked-by: Kazuhito Hagio Signed-off-by: Lianbo Jiang --- 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