@@ -23,6 +23,7 @@
typedef u32 note_buf_t[CRASH_CORE_NOTE_BYTES/4];
+void crash_update_vmcoreinfo_safecopy(void *ptr);
void crash_save_vmcoreinfo(void);
void arch_crash_save_vmcoreinfo(void);
__printf(1, 2)
@@ -54,7 +55,6 @@
vmcoreinfo_append_str("PHYS_BASE=%lx\n", (unsigned long)value)
extern u32 *vmcoreinfo_note;
-extern size_t vmcoreinfo_size;
Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type,
void *data, size_t data_len);
@@ -181,6 +181,7 @@ struct kimage {
unsigned long start;
struct page *control_code_page;
struct page *swap_page;
+ void *vmcoreinfo_data_copy; /* locates in the crash memory */
unsigned long nr_segments;
struct kexec_segment segment[KEXEC_SEGMENT_MAX];
@@ -250,6 +251,7 @@ extern void *kexec_purgatory_get_symbol_addr(struct kimage *image,
int kexec_should_crash(struct task_struct *);
int kexec_crash_loaded(void);
void crash_save_cpu(struct pt_regs *regs, int cpu);
+extern int kimage_crash_copy_vmcoreinfo(struct kimage *image);
extern struct kimage *kexec_image;
extern struct kimage *kexec_crash_image;
@@ -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();
}
@@ -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)
@@ -481,6 +481,40 @@ 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)
@@ -568,6 +602,11 @@ 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) {
@@ -304,6 +304,14 @@ void kimage_file_post_load_cleanup(struct kimage *image)
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;