From 4580a3d11db199683aaa7e2d7f03cd8d943f5af8 Mon Sep 17 00:00:00 2001
From: Tao Zeng <tao.zeng@amlogic.com>
Date: Thu, 7 Mar 2019 10:17:29 +0800
Subject: [PATCH] vmap: print pfn for register in vmalloc range [1/1]

PD#SWPL-5564

Problem:
When open VMAP for kernel stack, if we meet kernel panic log, we
can't know physical address of stack and hard to debug.

Solution:
Print pfn for register in vmalloc range

Verify:
p212

Change-Id: Iee120df1feab88e412ef63e87c2e2bb4ad0645fb
Signed-off-by: Tao Zeng <tao.zeng@amlogic.com>
---
 arch/arm/kernel/process.c   | 21 +++++++++++++++++++++
 arch/arm64/kernel/process.c | 18 ++++++++++++++++++
 2 files changed, 39 insertions(+)

diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 324b32b..c0c1730 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -350,6 +350,23 @@ done:
 		pr_cont("%s", name);
 	pr_cont("\n");
 }
+
+static void show_vmalloc_pfn(struct pt_regs *regs)
+{
+	int i;
+	struct page *page;
+
+	for (i = 0; i < 16; i++) {
+		if (is_vmalloc_or_module_addr((void *)regs->uregs[i])) {
+			page = vmalloc_to_page((void *)regs->uregs[i]);
+			if (!page)
+				continue;
+			pr_info("R%-2d : %08lx, PFN:%5lx\n",
+				i, regs->uregs[i], page_to_pfn(page));
+		}
+	}
+
+}
 #endif /* CONFIG_AMLOGIC_USER_FAULT */
 
 void __show_regs(struct pt_regs *regs)
@@ -408,6 +425,10 @@ void __show_regs(struct pt_regs *regs)
 	buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
 	buf[4] = '\0';
 
+#ifdef CONFIG_AMLOGIC_USER_FAULT
+	show_vmalloc_pfn(regs);
+#endif
+
 #ifndef CONFIG_CPU_V7M
 	{
 		const char *segment;
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 6084d01..7f377c1 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -268,6 +268,23 @@ static void show_user_data(unsigned long addr, int nbytes, const char *name)
 		pr_cont("\n");
 	}
 }
+
+static void show_vmalloc_pfn(struct pt_regs *regs)
+{
+	int i;
+	struct page *page;
+
+	for (i = 0; i < 16; i++) {
+		if (is_vmalloc_or_module_addr((void *)regs->regs[i])) {
+			page = vmalloc_to_page((void *)regs->regs[i]);
+			if (!page)
+				continue;
+			pr_info("R%-2d : %016llx, PFN:%5lx\n",
+				i, regs->regs[i], page_to_pfn(page));
+		}
+	}
+
+}
 #endif /* CONFIG_AMLOGIC_USER_FAULT */
 
 static void show_extra_register_data(struct pt_regs *regs, int nbytes)
@@ -443,6 +460,7 @@ void __show_regs(struct pt_regs *regs)
 		show_vma(current->mm, instruction_pointer(regs));
 		show_vma(current->mm, lr);
 	}
+	show_vmalloc_pfn(regs);
 #endif /* CONFIG_AMLOGIC_USER_FAULT */
 	printk("pc : [<%016llx>] lr : [<%016llx>] pstate: %08llx\n",
 	       regs->pc, lr, regs->pstate);
-- 
2.7.4