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Diffstat (limited to 'kernel')
-rw-r--r--kernel/crash_core.c17
-rw-r--r--kernel/kexec.c8
-rw-r--r--kernel/kexec_core.c39
-rw-r--r--kernel/kexec_file.c8
4 files changed, 71 insertions, 1 deletions
diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index 315adbf9cb68..6db80fc0810b 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -15,9 +15,12 @@
/* vmcoreinfo stuff */
static unsigned char *vmcoreinfo_data;
-size_t vmcoreinfo_size;
+static size_t vmcoreinfo_size;
u32 *vmcoreinfo_note;
+/* trusted vmcoreinfo, e.g. we can make a copy in the crash memory */
+static unsigned char *vmcoreinfo_data_safecopy;
+
/*
* parsing the "crashkernel" commandline
*
@@ -323,11 +326,23 @@ static void update_vmcoreinfo_note(void)
final_note(buf);
}
+void crash_update_vmcoreinfo_safecopy(void *ptr)
+{
+ if (ptr)
+ memcpy(ptr, vmcoreinfo_data, vmcoreinfo_size);
+
+ vmcoreinfo_data_safecopy = ptr;
+}
+
void crash_save_vmcoreinfo(void)
{
if (!vmcoreinfo_note)
return;
+ /* Use the safe copy to generate vmcoreinfo note if have */
+ if (vmcoreinfo_data_safecopy)
+ vmcoreinfo_data = vmcoreinfo_data_safecopy;
+
vmcoreinfo_append_str("CRASHTIME=%ld\n", get_seconds());
update_vmcoreinfo_note();
}
diff --git a/kernel/kexec.c b/kernel/kexec.c
index 980936a90ee6..e62ec4dc6620 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -144,6 +144,14 @@ static int do_kexec_load(unsigned long entry, unsigned long nr_segments,
if (ret)
goto out;
+ /*
+ * Some architecture(like S390) may touch the crash memory before
+ * machine_kexec_prepare(), we must copy vmcoreinfo data after it.
+ */
+ ret = kimage_crash_copy_vmcoreinfo(image);
+ if (ret)
+ goto out;
+
for (i = 0; i < nr_segments; i++) {
ret = kimage_load_segment(image, &image->segment[i]);
if (ret)
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index 154ffb489b93..1ae7c41c33c1 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -482,6 +482,40 @@ struct page *kimage_alloc_control_pages(struct kimage *image,
return pages;
}
+int kimage_crash_copy_vmcoreinfo(struct kimage *image)
+{
+ struct page *vmcoreinfo_page;
+ void *safecopy;
+
+ if (image->type != KEXEC_TYPE_CRASH)
+ return 0;
+
+ /*
+ * For kdump, allocate one vmcoreinfo safe copy from the
+ * crash memory. as we have arch_kexec_protect_crashkres()
+ * after kexec syscall, we naturally protect it from write
+ * (even read) access under kernel direct mapping. But on
+ * the other hand, we still need to operate it when crash
+ * happens to generate vmcoreinfo note, hereby we rely on
+ * vmap for this purpose.
+ */
+ vmcoreinfo_page = kimage_alloc_control_pages(image, 0);
+ if (!vmcoreinfo_page) {
+ pr_warn("Could not allocate vmcoreinfo buffer\n");
+ return -ENOMEM;
+ }
+ safecopy = vmap(&vmcoreinfo_page, 1, VM_MAP, PAGE_KERNEL);
+ if (!safecopy) {
+ pr_warn("Could not vmap vmcoreinfo buffer\n");
+ return -ENOMEM;
+ }
+
+ image->vmcoreinfo_data_copy = safecopy;
+ crash_update_vmcoreinfo_safecopy(safecopy);
+
+ return 0;
+}
+
static int kimage_add_entry(struct kimage *image, kimage_entry_t entry)
{
if (*image->entry != 0)
@@ -569,6 +603,11 @@ void kimage_free(struct kimage *image)
if (!image)
return;
+ if (image->vmcoreinfo_data_copy) {
+ crash_update_vmcoreinfo_safecopy(NULL);
+ vunmap(image->vmcoreinfo_data_copy);
+ }
+
kimage_free_extra_pages(image);
for_each_kimage_entry(image, ptr, entry) {
if (entry & IND_INDIRECTION) {
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 766e7e4d3ad9..c8f7f77e9fa9 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -298,6 +298,14 @@ SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd,
if (ret)
goto out;
+ /*
+ * Some architecture(like S390) may touch the crash memory before
+ * machine_kexec_prepare(), we must copy vmcoreinfo data after it.
+ */
+ ret = kimage_crash_copy_vmcoreinfo(image);
+ if (ret)
+ goto out;
+
ret = kexec_calculate_store_digests(image);
if (ret)
goto out;