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-rw-r--r--include/linux/kexec.h6
-rw-r--r--kernel/kexec.c21
2 files changed, 25 insertions, 2 deletions
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 07d9aba75562..fe45136b32cc 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -37,6 +37,10 @@
#define KEXEC_CRASH_CONTROL_MEMORY_LIMIT KEXEC_CONTROL_MEMORY_LIMIT
#endif
+#ifndef KEXEC_CRASH_MEM_ALIGN
+#define KEXEC_CRASH_MEM_ALIGN PAGE_SIZE
+#endif
+
#define KEXEC_NOTE_HEAD_BYTES ALIGN(sizeof(struct elf_note), 4)
#define KEXEC_CORE_NOTE_NAME "CORE"
#define KEXEC_CORE_NOTE_NAME_BYTES ALIGN(sizeof(KEXEC_CORE_NOTE_NAME), 4)
@@ -133,6 +137,8 @@ extern void crash_kexec(struct pt_regs *);
int kexec_should_crash(struct task_struct *);
void crash_save_cpu(struct pt_regs *regs, int cpu);
void crash_save_vmcoreinfo(void);
+void crash_map_reserved_pages(void);
+void crash_unmap_reserved_pages(void);
void arch_crash_save_vmcoreinfo(void);
void vmcoreinfo_append_str(const char *fmt, ...)
__attribute__ ((format (printf, 1, 2)));
diff --git a/kernel/kexec.c b/kernel/kexec.c
index d3b8a4ceb90b..dc7bc0829286 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -999,6 +999,7 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
kimage_free(xchg(&kexec_crash_image, NULL));
result = kimage_crash_alloc(&image, entry,
nr_segments, segments);
+ crash_map_reserved_pages();
}
if (result)
goto out;
@@ -1015,6 +1016,8 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
goto out;
}
kimage_terminate(image);
+ if (flags & KEXEC_ON_CRASH)
+ crash_unmap_reserved_pages();
}
/* Install the new kernel, and Uninstall the old */
image = xchg(dest_image, image);
@@ -1026,6 +1029,18 @@ out:
return result;
}
+/*
+ * Add and remove page tables for crashkernel memory
+ *
+ * Provide an empty default implementation here -- architecture
+ * code may override this
+ */
+void __weak crash_map_reserved_pages(void)
+{}
+
+void __weak crash_unmap_reserved_pages(void)
+{}
+
#ifdef CONFIG_COMPAT
asmlinkage long compat_sys_kexec_load(unsigned long entry,
unsigned long nr_segments,
@@ -1134,14 +1149,16 @@ int crash_shrink_memory(unsigned long new_size)
goto unlock;
}
- start = roundup(start, PAGE_SIZE);
- end = roundup(start + new_size, PAGE_SIZE);
+ start = roundup(start, KEXEC_CRASH_MEM_ALIGN);
+ end = roundup(start + new_size, KEXEC_CRASH_MEM_ALIGN);
+ crash_map_reserved_pages();
crash_free_reserved_phys_range(end, crashk_res.end);
if ((start == end) && (crashk_res.parent != NULL))
release_resource(&crashk_res);
crashk_res.end = end - 1;
+ crash_unmap_reserved_pages();
unlock:
mutex_unlock(&kexec_mutex);