Pass vmcoreinfo's address and size #2

There is a compatibility problem that the kexec command fails on
kernels which don't have /sys/kernel/vmcoreinfo:

 # ls /sys/kernel/
 debug  kexec_crash_loaded  kexec_loaded  security  uevent_helper
 uevent_seqnum
 #
 (There is not /sys/kernel/vmcoreinfo.)

 #
 # kexec -p --args-linux vmlinuz --initrd=initrd.img
 Could not open "/sys/kernel/vmcoreinfo": No such file or directory
 #

To fix the problem, could you please apply the attached patch ?
The fixed part is the same as the patch in the following mail.

Cc: "Ken'ichi Ohmichi" <oomichi@mxs.nes.nec.co.jp>
Signed-off-by: Simon Horman <horms@verge.net.au>

1 files changed, 2 insertions, 6 deletions

diff --git a/kexec/crashdump.c b/kexec/crashdump.c
index a35f7a7..42ec3ab 100644
--- a/kexec/crashdump.c
+++ b/kexec/crashdump.c
@@ -122,12 +122,8 @@ int get_kernel_vmcoreinfo(uint64_t *addr, uint64_t *len)
 	*len = 0;
 
 	sprintf(kdump_info, "/sys/kernel/vmcoreinfo");
-	fp = fopen(kdump_info, "r");
-	if (!fp) {
-		die("Could not open \"%s\": %s\n", kdump_info,
-		    strerror(errno));
-		return -1;
-	}
+	if (!(fp = fopen(kdump_info, "r")))
+		return 0;
 
 	if (!fgets(line, sizeof(line), fp))
 		die("Cannot parse %s: %s\n", kdump_info, strerror(errno));