From 08e08d1330f5d4dd0989bfb1558d85c82254654e Mon Sep 17 00:00:00 2001

From: Bhupesh Sharma <bhsharma@redhat.com>

Date: Fri, 17 Nov 2017 06:30:41 +0900

Subject: [PATCH 2/2] [PATCH 2/2] Fix 'kernel_version' variable being

 uninitialized & introduce minor reorganization

On executing `makedumpfile --mem-usage /proc/kcore`, it

fails currently with the following error message on newer Linux kernels

like 4.13.0 or 4.14.0:

mem-usage not supported for this kernel.

You can try with -f if your kernel's kcore has valid p_paddr

makedumpfile Failed.

This happens because 'info->kernel_version' is uninitialized in function

main(). So when we perform the following check, it fails even though the

kernel version is greater than 4.11.0:

if (info->kernel_version < KERNEL_VERSION(4, 11, 0) &&

				!info->flag_force) {

Fix this by reorganizing the code to:

- Add an API to populate the kernel version.

- Call this API rather than replicating the open code across other APIs

  across 'makedumpfile.c'

After this patch, '--mem-usage' can be used properly with makedumpfile.

Here are the logs I observe on a Fedora 26 ppc64le system:

The kernel version is not supported.

The makedumpfile operation may be incomplete.

TYPE		PAGES			EXCLUDABLE	DESCRIPTION

----------------------------------------------------------------------

ZERO		99              	yes		Pages filled with zero

NON_PRI_CACHE	7817            	yes		Cache pages without private flag

PRI_CACHE		63603           	yes		Cache pages with private flag

USER		4105            	yes		User process pages

FREE		165446          	yes		Free pages

KERN_DATA		6738            	no		Dumpable kernel data

page size:		65536

Total pages on system:	247808

Total size on system:	16240345088      Byte

Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com>

---

 makedumpfile.c | 31 ++++++++++++++++++++-----------

 1 file changed, 20 insertions(+), 11 deletions(-)

diff --git a/makedumpfile-1.6.2/makedumpfile.c b/makedumpfile-1.6.2/makedumpfile.c

index 7ce0c6d648aa..4bde542b4f0c 100644

--- a/makedumpfile-1.6.2/makedumpfile.c

+++ b/makedumpfile-1.6.2/makedumpfile.c

@@ -1089,6 +1089,21 @@ fallback_to_current_page_size(void)

 	return TRUE;

 }

+static int populate_kernel_version(void)

+{

+	struct utsname utsname;

+

+	if (uname(&utsname)) {

+		ERRMSG("Cannot get name and information about current kernel : %s\n",

+		       strerror(errno));

+		return FALSE;

+	}

+

+	info->kernel_version = get_kernel_version(utsname.release);

+

+	return TRUE;

+}

+

 int

 check_release(void)

 {

@@ -1120,11 +1135,8 @@ check_release(void)

 		}

 	}

-	info->kernel_version = get_kernel_version(info->system_utsname.release);

-	if (info->kernel_version == FALSE) {

-		ERRMSG("Can't get the kernel version.\n");

+	if (!populate_kernel_version())

 		return FALSE;

-	}

 	return TRUE;

 }

@@ -10973,20 +10985,14 @@ int is_crashkernel_mem_reserved(void)

 static int get_page_offset(void)

 {

-	struct utsname utsname;

-	if (uname(&utsname)) {

-		ERRMSG("Cannot get name and information about current kernel : %s",

-		       strerror(errno));

+	if (!populate_kernel_version())

 		return FALSE;

-	}

-	info->kernel_version = get_kernel_version(utsname.release);

 	get_versiondep_info();

 	return TRUE;

 }

-

 /* Returns the physical address of start of crash notes buffer for a kernel. */

 static int get_sys_kernel_vmcoreinfo(uint64_t *addr, uint64_t *len)

 {

@@ -11363,6 +11369,9 @@ main(int argc, char *argv[])

 			MSG("Try `makedumpfile --help' for more information.\n");

 			goto out;

 		}

+		if (!populate_kernel_version())

+			goto out;

+

 		if (info->kernel_version < KERNEL_VERSION(4, 11, 0) &&

 				!info->flag_force) {

 			MSG("mem-usage not supported for this kernel.\n");

-- 

2.7.4