Re: [Crash-utility] [PATCH v3] Fix pvops Xen detection for arm machine

Date: Tue, 21 Dec 2021 15:40:31 +0800 From: Qi Zheng <zhengqi.arch(a)bytedance.com&gt; To: lijiang(a)redhat.com, k-hagio-ab(a)nec.com Cc: Qi Zheng <zhengqi.arch(a)bytedance.com&gt;, crash-utility(a)redhat.com Subject: [Crash-utility] [PATCH v3] Fix pvops Xen detection for arm machine Message-ID: <20211221074031.51379-1-zhengqi.arch(a)bytedance.com&gt; Content-Type: text/plain; charset="US-ASCII" Since the xen_start_info on the arm/arm64 platform is static defined: ./arm/xen/enlighten.c:40:static struct start_info _xen_start_info; ./arm/xen/enlighten.c:41:struct start_info *xen_start_info = &_xen_start_info; ./arm/xen/enlighten.c:42:EXPORT_SYMBOL(xen_start_info); The is_pvops_xen() in commit 4badc6229c69f5cd9da7eb7bdf400a53ec6db01a ("Fix pvops Xen detection for kernels >= v4.20") always return TRUE. Then the following error will be reported 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. And considering that xen_start_info is only defined on x86 and arm platform, use machine_type() to explicitly narrow the scope of the xen_start_info check to x86. Signed-off-by: Qi Zheng <zhengqi.arch(a)bytedance.com&gt; Acked-by: Kazuhito Hagio <k-hagio-ab(a)nec.com&gt; --- kernel.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/kernel.c b/kernel.c index f4598ea..37b7af7 100644 --- a/kernel.c +++ b/kernel.c @@ -10757,11 +10757,21 @@ 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; } -- changes since [v2]: - use machine_type() to explicitly narrow the scope of the xen_start_info check to x86. - Collect Acked-by from Kazu. [v1]: https://listman.redhat.com/archives/crash-utility/2021-December/msg00007.... [v2]: https://listman.redhat.com/archives/crash-utility/2021-December/msg00028.... 2.11.0