| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <1214468067-1231-3-git-send-email-bwalle@suse.de>
Date: Thu, 26 Jun 2008 10:14:27 +0200
From: Bernhard Walle <bwalle@...e.de>
To: x86@...nel.org
Cc: linux-kernel@...r.kernel.org, kexec@...ts.infradead.org,
yhlu.kernel@...il.com, vgoyal@...hat.com,
Bernhard Walle <bwalle@...e.de>
Subject: [PATCH 2/2] Use FIRMWARE_MEMMAP on x86/E820
This patch uses the /sys/firmware/memmap interface provided in the last patch
on the x86 architecture when E820 is used. The patch copies the E820
memory map very early, and registers the E820 map afterwards via
firmware_map_add_early().
Signed-off-by: Bernhard Walle <bwalle@...e.de>
---
arch/x86/kernel/e820.c | 42 ++++++++++++++++++++++++++++++++++++------
include/asm-x86/e820.h | 2 ++
2 files changed, 38 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 3771386..c27863e 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -19,6 +19,7 @@
#include <linux/mm.h>
#include <linux/pfn.h>
#include <linux/suspend.h>
+#include <linux/firmware-map.h>
#include <asm/pgtable.h>
#include <asm/page.h>
@@ -27,7 +28,22 @@
#include <asm/setup.h>
#include <asm/trampoline.h>
+/*
+ * The e820 map is the map that gets modified e.g. with command line parameters
+ * and that is also registered with modifications in the kernel resource tree
+ * with the iomem_resource as parent.
+ *
+ * The e820_saved is directly saved after the BIOS-provided memory map is
+ * copied. It doesn't get modified afterwards. It's registered for the
+ * /sys/firmware/memmap interface.
+ *
+ * That memory map is not modified and is used as base for kexec. The kexec'd
+ * kernel should get the same memory map as the firmware provides. Then the
+ * user can e.g. boot the original kernel with mem=1G while still booting the
+ * next kernel with full memory.
+ */
struct e820map e820;
+struct e820map e820_saved;
/* For PCI or other memory-mapped resources */
unsigned long pci_mem_start = 0xaeedbabe;
@@ -1056,6 +1072,16 @@ void __init finish_e820_parsing(void)
}
}
+static inline const char *e820_type_to_string(int e820_type)
+{
+ switch (e820_type) {
+ case E820_RAM: return "System RAM";
+ case E820_ACPI: return "ACPI Tables";
+ case E820_NVS: return "ACPI Non-volatile Storage";
+ default: return "reserved";
+ }
+}
+
/*
* Mark e820 reserved areas as busy for the resource manager.
*/
@@ -1066,12 +1092,7 @@ void __init e820_reserve_resources(void)
res = alloc_bootmem_low(sizeof(struct resource) * e820.nr_map);
for (i = 0; i < e820.nr_map; i++) {
- switch (e820.map[i].type) {
- case E820_RAM: res->name = "System RAM"; break;
- case E820_ACPI: res->name = "ACPI Tables"; break;
- case E820_NVS: res->name = "ACPI Non-volatile Storage"; break;
- default: res->name = "reserved";
- }
+ res->name = e820_type_to_string(e820.map[i].type);
res->start = e820.map[i].addr;
res->end = res->start + e820.map[i].size - 1;
#ifndef CONFIG_RESOURCES_64BIT
@@ -1084,6 +1105,13 @@ void __init e820_reserve_resources(void)
insert_resource(&iomem_resource, res);
res++;
}
+
+ for (i = 0; i < e820_saved.nr_map; i++) {
+ struct e820entry *entry = &e820_saved.map[i];
+ firmware_map_add_early(entry->addr,
+ entry->addr + entry->size - 1,
+ e820_type_to_string(entry->type));
+ }
}
char *__init default_machine_specific_memory_setup(void)
@@ -1119,6 +1147,8 @@ char *__init default_machine_specific_memory_setup(void)
e820_add_region(HIGH_MEMORY, mem_size << 10, E820_RAM);
}
+ memcpy(&e820_saved, &e820, sizeof(struct e820map));
+
/* In case someone cares... */
return who;
}
diff --git a/include/asm-x86/e820.h b/include/asm-x86/e820.h
index 13a0a5f..607f940 100644
--- a/include/asm-x86/e820.h
+++ b/include/asm-x86/e820.h
@@ -56,7 +56,9 @@ struct e820map {
struct e820entry map[E820_X_MAX];
};
+/* see comment in arch/x86/kernel/e820.c */
extern struct e820map e820;
+extern struct e820map e820_saved;
extern int e820_any_mapped(u64 start, u64 end, unsigned type);
extern int e820_all_mapped(u64 start, u64 end, unsigned type);
--
1.5.6
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists