From b7a67e02cd2b0d632114dcfb4bfb9b1d85dee325 Mon Sep 17 00:00:00 2001
From: Chen Yu <yu.c.chen@intel.com>
Date: Mon, 3 Jul 2017 01:06:28 +0800
Subject: [PATCH] x86/boot/e820: Avoid overwriting e820_table_firmware
Git-commit: b7a67e02cd2b0d632114dcfb4bfb9b1d85dee325
Patch-mainline: v4.13-rc1
References: bsc#1127154

The following commit in 2013:

  77ea8c948953 ("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>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 arch/x86/kernel/e820.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index d78a586ba8dc..c87223e5b1aa 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -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");
-- 
2.16.4