Commit b7a67e02 authored Jul 03, 2017 by Chen Yu Committed by Ingo Molnar Jul 05, 2017

x86/boot/e820: Avoid overwriting e820_table_firmware



The following commit in 2013:

  77ea8c94 ("x86: Reserve setup_data ranges late after parsing memmap cmdline")

has fixed the issue of losing setup_data information by deferring the
e820_reserve_setup_data() call until the early params have been parsed.

But this also introduced a new problem that, during early params parsing,
the kexec kernel might fake a mptable and saves it into the e820_table_firmware[]
table (without saving the mptable to the e820_table[]), however the subsequent
invoking of e820_reserve_setup_data() will overwrite the e820_table_firmware[]
according to the e820_table[], thus the fake mptable information is lost.

Fix this issue by updating the e820_table_firmware[] according to
the setup_data information, but without overwriting it.

Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Xunlei Pang <xlpang@redhat.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 99c13b8c

arch/x86/kernel/e820.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -669,6 +669,8 @@ void __init e820__memory_setup_extended(u64 phys_addr, u32 data_len)
		__append_e820_table(extmap, entries);
		e820__update_table(e820_table);

		memcpy(e820_table_firmware, e820_table, sizeof(*e820_table_firmware));

		early_memunmap(sdata, data_len);
		pr_info("e820: extended physical RAM map:\n");
		e820__print_table("extended");
		@@ -923,13 +925,13 @@ void __init e820__reserve_setup_data(void)
		while (pa_data) {
		data = early_memremap(pa_data, sizeof(*data));
		e820__range_update(pa_data, sizeof(*data)+data->len, E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
		e820__range_update_firmware(pa_data, sizeof(*data)+data->len, E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
		pa_data = data->next;
		early_memunmap(data, sizeof(*data));
		}

		e820__update_table(e820_table);

		memcpy(e820_table_firmware, e820_table, sizeof(*e820_table_firmware));
		e820__update_table(e820_table_firmware);

		pr_info("extended physical RAM map:\n");
		e820__print_table("reserve setup_data");

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