4.4-stable review patch. If anyone has any objections, please let me know.
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From: Mahesh Salgaonkar mahesh@linux.vnet.ibm.com
commit 722cde76d68e8cc4f3de42e71c82fd40dea4f7b9 upstream.
Unregister fadump on kexec down path otherwise the fadump registration in new kexec-ed kernel complains that fadump is already registered. This makes new kernel to continue using fadump registered by previous kernel which may lead to invalid vmcore generation. Hence this patch fixes this issue by un-registering fadump in fadump_cleanup() which is called during kexec path so that new kernel can register fadump with new valid values.
Fixes: b500afff11f6 ("fadump: Invalidate registration and release reserved memory for general use.") Cc: stable@vger.kernel.org # v3.4+ Signed-off-by: Mahesh Salgaonkar mahesh@linux.vnet.ibm.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/powerpc/kernel/fadump.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/arch/powerpc/kernel/fadump.c +++ b/arch/powerpc/kernel/fadump.c @@ -1025,6 +1025,9 @@ void fadump_cleanup(void) init_fadump_mem_struct(&fdm, be64_to_cpu(fdm_active->cpu_state_data.destination_address)); fadump_invalidate_dump(&fdm); + } else if (fw_dump.dump_registered) { + /* Un-register Firmware-assisted dump if it was registered. */ + fadump_unregister_dump(&fdm); } }