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authorPetr Tesarik <ptesarik@suse.com>2016-08-02 14:06:16 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-08-02 19:35:30 -0400
commit21db79e8bb054d0351a6b1b464f1c9c47a2e6e8d (patch)
treea34bbff53fad1569f11eac002eeef688ed5dd170 /kernel
parentb26e27ddfd2a986dc53e259aba572f3aac182eb8 (diff)
kexec: add a kexec_crash_loaded() function
Provide a wrapper function to be used by kernel code to check whether a crash kernel is loaded. It returns the same value that can be seen in /sys/kernel/kexec_crash_loaded by userspace programs. I'm exporting the function, because it will be used by Xen, and it is possible to compile Xen modules separately to enable the use of PV drivers with unmodified bare-metal kernels. Link: http://lkml.kernel.org/r/20160713121955.14969.69080.stgit@hananiah.suse.cz Signed-off-by: Petr Tesarik <ptesarik@suse.com> Cc: Juergen Gross <jgross@suse.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Eric Biederman <ebiederm@xmission.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/kexec_core.c6
-rw-r--r--kernel/ksysfs.c2
2 files changed, 7 insertions, 1 deletions
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index 73d4c5f57dd8..704534029a00 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -95,6 +95,12 @@ int kexec_should_crash(struct task_struct *p)
return 0;
}
+int kexec_crash_loaded(void)
+{
+ return !!kexec_crash_image;
+}
+EXPORT_SYMBOL_GPL(kexec_crash_loaded);
+
/*
* When kexec transitions to the new kernel there is a one-to-one
* mapping between physical and virtual addresses. On processors
diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c
index 9f1920d2d0c6..ee1bc1bb8feb 100644
--- a/kernel/ksysfs.c
+++ b/kernel/ksysfs.c
@@ -101,7 +101,7 @@ KERNEL_ATTR_RO(kexec_loaded);
static ssize_t kexec_crash_loaded_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
- return sprintf(buf, "%d\n", !!kexec_crash_image);
+ return sprintf(buf, "%d\n", kexec_crash_loaded());
}
KERNEL_ATTR_RO(kexec_crash_loaded);