From 61765090769c1c95d94bdd2ddc9933df1c0a0bad Mon Sep 17 00:00:00 2001
From: Marc Hartmayer <mhartmay@linux.ibm.com>
Date: Fri, 23 Sep 2022 13:58:43 +0000
Subject: [PATCH] zdump: df_elf: refactor `check_elf_hdr`
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The function will be reused by upcoming patches.

Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
---
 zdump/df_elf.c  |  9 +++++++++
 zdump/df_elf.h  |  5 +++++
 zdump/dfi_elf.c | 11 +----------
 3 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/zdump/df_elf.c b/zdump/df_elf.c
index a1780e21..602080f7 100644
--- a/zdump/df_elf.c
+++ b/zdump/df_elf.c
@@ -52,6 +52,15 @@ bool ehdr_is_s390x(const Elf64_Ehdr *ehdr)
 	       ehdr->e_ident[EI_CLASS] == ELFCLASS64;
 }
 
+int ehdr_check_s390x(const Elf64_Ehdr *ehdr)
+{
+	if (!ehdr_is_elf_object(ehdr) || !ehdr_is_vmcore(ehdr))
+		return -ENODEV;
+	if (!ehdr_is_s390x(ehdr))
+		ERR_EXIT("Only s390x (64 bit) core dump files are supported");
+	return 0;
+}
+
 Elf64_Ehdr *read_elf_hdr(const struct zg_fh *fh)
 {
 	Elf64_Ehdr *ehdr;
diff --git a/zdump/df_elf.h b/zdump/df_elf.h
index 583217fa..11441f0b 100644
--- a/zdump/df_elf.h
+++ b/zdump/df_elf.h
@@ -147,6 +147,11 @@ bool ehdr_is_vmcore(const Elf64_Ehdr *ehdr);
  */
 bool ehdr_is_s390x(const Elf64_Ehdr *ehdr);
 
+/*
+ * Verify that given header is a s390x ELF header
+ */
+int ehdr_check_s390x(const Elf64_Ehdr *ehdr);
+
 /*
  * Read ELF header at current offset
  */
diff --git a/zdump/dfi_elf.c b/zdump/dfi_elf.c
index 102a4a4d..605904bc 100644
--- a/zdump/dfi_elf.c
+++ b/zdump/dfi_elf.c
@@ -251,15 +251,6 @@ static int pt_notes_add(const Elf64_Phdr *phdr)
 	return 0;
 }
 
-static int check_elf_hdr(const Elf64_Ehdr *ehdr)
-{
-	if (!ehdr_is_elf_object(ehdr) || !ehdr_is_vmcore(ehdr))
-		return -ENODEV;
-	if (!ehdr_is_s390x(ehdr))
-		ERR_EXIT("Only s390x (64 bit) core dump files are supported");
-	return 0;
-}
-
 /*
  * Initialize ELF input dump format
  */
@@ -276,7 +267,7 @@ static int dfi_elf_init(void)
 	if (!ehdr)
 		return -ENODEV;
 
-	if (check_elf_hdr(ehdr) < 0)
+	if (ehdr_check_s390x(ehdr) < 0)
 		goto free_ehdr;
 
 	df_elf_ensure_s390x();