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

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" Fix it by using xen_vcpu_id instead of xen_start_info to detect Xen dumps. Signed-off-by: Qi Zheng <zhengqi.arch(a)bytedance.com&gt; --- kernel.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) diff --git a/kernel.c b/kernel.c index f4598ea..b216fbe 100644 --- a/kernel.c +++ b/kernel.c @@ -10745,6 +10745,9 @@ is_pvops_xen(void) { ulong addr; char *sym; + struct syment * sp; + ulong ptr; + int i; if (!PVOPS()) return FALSE; @@ -10757,11 +10760,19 @@ 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; + sp = per_cpu_symbol_search("xen_vcpu_id"); + if (sp) { + for (i = 0; i < NR_CPUS; i++) { + if (!kt->__per_cpu_offset[i]) + continue;

+ + ptr = sp->value + kt->__per_cpu_offset[i]; + if (ptr && readmem(ptr, KVADDR, &ptr, sizeof(uint32_t), + "xen_vcpu_id", FAULT_ON_ERROR)) + return TRUE; + return FALSE; + } + } return FALSE; } -- 2.11.0