powerpc/kdump: Handle crashkernel memory reservation failure

Memory reservation for crashkernel could fail if there are holes around
kdump kernel offset (128M). Fail gracefully in such cases and print an
error message.

Signed-off-by: Hari Bathini <[email protected]>
Tested-by: David Gibson <[email protected]>
Reviewed-by: Dave Young <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>

diff --git a/arch/powerpc/kernel/machine_kexec.c b/arch/powerpc/kernel/machine_kexec.c
index 936c7e2d421e7b5fa6eab58b20d4fbc7fd7d5fd7..b53401334e81b5fbfed75605922afcb1f4f8d5b6 100644 (file)
--- a/arch/powerpc/kernel/machine_kexec.c
+++ b/arch/powerpc/kernel/machine_kexec.c
@@ -188,7 +188,12 @@ void __init reserve_crashkernel(void)
                        (unsigned long)(crashk_res.start >> 20),
                        (unsigned long)(memblock_phys_mem_size() >> 20));
 
-       memblock_reserve(crashk_res.start, crash_size);
+       if (!memblock_is_region_memory(crashk_res.start, crash_size) ||
+           memblock_reserve(crashk_res.start, crash_size)) {
+               pr_err("Failed to reserve memory for crashkernel!\n");
+               crashk_res.start = crashk_res.end = 0;
+               return;
+       }
 }
 
 int overlaps_crashkernel(unsigned long start, unsigned long size)