From: Yinghai Lu <yinghai@kernel.org>
To: Kees Cook <keescook@chromium.org>,
"H. Peter Anvin" <hpa@zytor.com>, Baoquan He <bhe@redhat.com>
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH 17/42] x86, kaslr: Add support of kernel physical address randomization above 4G
Date: Tue, 7 Jul 2015 13:20:03 -0700 [thread overview]
Message-ID: <1436300428-21163-18-git-send-email-yinghai@kernel.org> (raw)
In-Reply-To: <1436300428-21163-1-git-send-email-yinghai@kernel.org>
From: Baoquan He <bhe@redhat.com>
In kaslr implementation mechanism, mainly process_e820_entry and
slots_fetch_random do the job. process_e820_entry is responsible
for storing the slot information. slots_fetch_random takes care
of fetching slot information. In this patch, for adding support
of kernel physical address randomization above 4G, both of these
two functions are changed based on the new slot_area data structure.
Now kernel can be reloaded and decompressed anywhere of the whole
physical memory, even near 64T at most.
Signed-off-by: Baoquan He <bhe@redhat.com>
---
arch/x86/boot/compressed/aslr.c | 68 ++++++++++++++++++++++++++++++-----------
1 file changed, 51 insertions(+), 17 deletions(-)
diff --git a/arch/x86/boot/compressed/aslr.c b/arch/x86/boot/compressed/aslr.c
index 554b637..9158882 100644
--- a/arch/x86/boot/compressed/aslr.c
+++ b/arch/x86/boot/compressed/aslr.c
@@ -293,27 +293,40 @@ static void slots_append(unsigned long addr)
static unsigned long slots_fetch_random(void)
{
+ unsigned long random;
+ int i;
+
/* Handle case of no slots stored. */
if (slot_max == 0)
return 0;
- return slots[get_random_long() % slot_max];
+ random = get_random_long() % slot_max;
+
+ for (i = 0; i < slot_area_index; i++) {
+ if (random >= slot_areas[i].num) {
+ random -= slot_areas[i].num;
+ continue;
+ }
+ return slot_areas[i].addr + random * CONFIG_PHYSICAL_ALIGN;
+ }
+
+ if (i == slot_area_index)
+ debug_putstr("Something wrong happened in slots_fetch_random()...\n");
+ return 0;
}
static void process_e820_entry(struct e820entry *entry,
unsigned long minimum,
unsigned long image_size)
{
- struct mem_vector region, img;
+ struct mem_vector region, out;
+ struct slot_area slot_area;
+ unsigned long min, start_orig;
/* Skip non-RAM entries. */
if (entry->type != E820_RAM)
return;
- /* Ignore entries entirely above our maximum. */
- if (entry->addr >= CONFIG_RANDOMIZE_BASE_MAX_OFFSET)
- return;
-
/* Ignore entries entirely below our minimum. */
if (entry->addr + entry->size < minimum)
return;
@@ -321,10 +334,17 @@ static void process_e820_entry(struct e820entry *entry,
region.start = entry->addr;
region.size = entry->size;
+repeat:
+ start_orig = region.start;
+
/* Potentially raise address to minimum location. */
if (region.start < minimum)
region.start = minimum;
+ /* Return if slot area array is full */
+ if (slot_area_index == MAX_SLOT_AREA)
+ return;
+
/* Potentially raise address to meet alignment requirements. */
region.start = ALIGN(region.start, CONFIG_PHYSICAL_ALIGN);
@@ -333,20 +353,30 @@ static void process_e820_entry(struct e820entry *entry,
return;
/* Reduce size by any delta from the original address. */
- region.size -= region.start - entry->addr;
+ region.size -= region.start - start_orig;
- /* Reduce maximum size to fit end of image within maximum limit. */
- if (region.start + region.size > CONFIG_RANDOMIZE_BASE_MAX_OFFSET)
- region.size = CONFIG_RANDOMIZE_BASE_MAX_OFFSET - region.start;
+ /* Return if region can't contain decompressed kernel */
+ if (region.size < image_size)
+ return;
- /* Walk each aligned slot and check for avoided areas. */
- for (img.start = region.start, img.size = image_size ;
- mem_contains(®ion, &img) ;
- img.start += CONFIG_PHYSICAL_ALIGN) {
- if (mem_avoid_overlap(&img))
- continue;
- slots_append(img.start);
+ if (!mem_avoid_overlap(®ion)) {
+ store_slot_info(®ion, image_size);
+ return;
}
+
+ min = mem_min_overlap(®ion, &out);
+
+ if (min > region.start + image_size) {
+ struct mem_vector tmp;
+
+ tmp.start = region.start;
+ tmp.size = min - region.start;
+ store_slot_info(&tmp, image_size);
+ }
+
+ region.size -= out.start - region.start + out.size;
+ region.start = out.start + out.size;
+ goto repeat;
}
static unsigned long find_random_phy_addr(unsigned long minimum,
@@ -361,6 +391,10 @@ static unsigned long find_random_phy_addr(unsigned long minimum,
/* Verify potential e820 positions, appending to slots list. */
for (i = 0; i < real_mode->e820_entries; i++) {
process_e820_entry(&real_mode->e820_map[i], minimum, size);
+ if (slot_area_index == MAX_SLOT_AREA) {
+ debug_putstr("Stop processing e820 since slot_areas is full...\n");
+ break;
+ }
}
return slots_fetch_random();
--
1.8.4.5
next prev parent reply other threads:[~2015-07-07 20:26 UTC|newest]
Thread overview: 79+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-07 20:19 [PATCH 00/42] x86: updated patches for kaslr and setup_data etc for v4.3 Yinghai Lu
2015-07-07 20:19 ` [PATCH 01/42] x86, kasl: Remove not needed parameter for choose_kernel_location Yinghai Lu
2015-07-07 20:57 ` Kees Cook
2015-07-07 20:19 ` [PATCH 02/42] x86, boot: Move compressed kernel to end of buffer before decompressing Yinghai Lu
2015-07-07 21:22 ` Kees Cook
2015-07-07 20:19 ` [PATCH 03/42] x86, boot: Fix run_size calculation Yinghai Lu
2015-07-07 22:15 ` Kees Cook
2015-07-07 20:19 ` [PATCH 04/42] x86, kaslr: Kill not needed and wrong run_size calculation code Yinghai Lu
2015-07-07 22:18 ` Kees Cook
2015-07-07 20:19 ` [PATCH 05/42] x86, kaslr: rename output_size to output_run_size Yinghai Lu
2015-07-07 20:19 ` [PATCH 06/42] x86, kaslr: Consolidate mem_avoid array filling Yinghai Lu
2015-07-07 22:36 ` Kees Cook
2015-07-07 20:19 ` [PATCH 07/42] x86, boot: Move z_extract_offset calculation to header.S Yinghai Lu
2015-07-07 20:19 ` [PATCH 08/42] x86, kaslr: Get correct max_addr for relocs pointer Yinghai Lu
2015-07-07 22:40 ` Kees Cook
2015-07-07 20:19 ` [PATCH 09/42] x86, boot: Split kernel_ident_mapping_init to another file Yinghai Lu
2015-07-07 20:19 ` [PATCH 10/42] x86, 64bit: Set ident_mapping for kaslr Yinghai Lu
2015-07-07 20:19 ` [PATCH 11/42] x86, boot: Add checking for memcpy Yinghai Lu
2015-07-07 20:19 ` [PATCH 12/42] x86, kaslr: Fix a bug that relocation can not be handled when kernel is loaded above 2G Yinghai Lu
2015-07-07 22:42 ` Kees Cook
2015-07-07 20:19 ` [PATCH 13/42] x86, kaslr: Introduce struct slot_area to manage randomization slot info Yinghai Lu
2015-07-07 20:20 ` [PATCH 14/42] x86, kaslr: Add two functions which will be used later Yinghai Lu
2015-07-07 20:20 ` [PATCH 15/42] x86, kaslr: Introduce fetch_random_virt_offset to randomize the kernel text mapping address Yinghai Lu
2015-07-07 20:20 ` [PATCH 16/42] x86, kaslr: Randomize physical and virtual address of kernel separately Yinghai Lu
2015-07-07 20:20 ` Yinghai Lu [this message]
2015-07-07 20:20 ` [PATCH 18/42] x86, kaslr: Remove useless codes Yinghai Lu
2015-07-07 20:20 ` [PATCH 19/42] x86, kaslr: Allow random address could be below loaded address Yinghai Lu
2015-07-07 20:20 ` [PATCH 20/42] x86, boot: Add printf support for early console in compressed/misc.c Yinghai Lu
2015-07-07 20:20 ` [PATCH 21/42] x86, boot: Add more debug printout " Yinghai Lu
2015-07-07 20:20 ` [PATCH 22/42] x86, setup: Check early serial console per string instead of one char Yinghai Lu
2015-07-07 22:59 ` Kees Cook
2015-07-07 20:20 ` [PATCH 23/42] x86, setup: Use puts() instead of printf() in edd code Yinghai Lu
2015-07-07 20:20 ` [PATCH 24/42] x86: Setup early console as early as possible in x86_start_kernel() Yinghai Lu
2015-07-07 20:20 ` [PATCH 25/42] x86, boot: print compression suffix in decompress stage Yinghai Lu
2015-07-07 23:13 ` Kees Cook
2015-07-07 20:20 ` [PATCH 26/42] x86: remove not needed clear_page calling Yinghai Lu
2015-07-07 23:14 ` Kees Cook
2015-07-07 20:20 ` [PATCH 27/42] x86: restore end_of_ram to E820_RAM Yinghai Lu
2015-07-08 17:44 ` Matt Fleming
2015-07-09 1:41 ` Dan Williams
2015-07-09 7:45 ` Christoph Hellwig
2015-07-09 11:17 ` Matt Fleming
2015-07-07 20:20 ` [PATCH 28/42] x86, boot: Allow 64bit EFI kernel to be loaded above 4G Yinghai Lu
2015-07-07 23:12 ` Kees Cook
2015-07-08 18:00 ` Matt Fleming
2015-07-07 20:20 ` [PATCH 29/42] x86: Find correct 64 bit ramdisk address for microcode early update Yinghai Lu
2015-07-07 23:08 ` Kees Cook
2015-07-07 20:20 ` [PATCH 30/42] x86: Kill E820_RESERVED_KERN Yinghai Lu
2015-07-07 20:20 ` [PATCH 31/42] x86, efi: Copy SETUP_EFI data and access directly Yinghai Lu
2015-07-22 10:58 ` Matt Fleming
2015-07-22 10:58 ` Matt Fleming
2015-07-24 2:07 ` Dave Young
2015-07-24 2:07 ` Dave Young
2015-07-07 20:20 ` [PATCH 32/42] x86, of: Let add_dtb reserve setup_data locally Yinghai Lu
2015-07-07 20:20 ` [PATCH 33/42] x86, boot: Add add_pci handler for SETUP_PCI Yinghai Lu
2015-07-14 22:30 ` Bjorn Helgaas
2015-07-07 20:20 ` [PATCH 34/42] x86: Kill not used setup_data handling code Yinghai Lu
2015-07-07 20:20 ` [PATCH 35/42] x86, boot, PCI: Convert SETUP_PCI data to list Yinghai Lu
2015-07-14 22:35 ` Bjorn Helgaas
2015-07-15 1:57 ` Yinghai Lu
2015-07-07 20:20 ` [PATCH 36/42] x86, boot, PCI: Copy SETUP_PCI rom to kernel space Yinghai Lu
2015-07-07 20:20 ` [PATCH 37/42] x86, boot, PCI: Export SETUP_PCI data via sysfs Yinghai Lu
2015-07-07 20:20 ` [PATCH 38/42] x86: Fix typo in mark_rodata_ro Yinghai Lu
2015-07-07 23:05 ` Kees Cook
2015-07-07 20:20 ` [PATCH 39/42] x86, 64bit: add pfn_range_is_highmapped() Yinghai Lu
2015-07-07 20:20 ` [PATCH 40/42] x86, 64bit: remove highmap for not needed ranges Yinghai Lu
2015-07-07 23:17 ` Kees Cook
2015-07-07 20:20 ` [PATCH 41/42] x86, 64bit: Add __pa_high/__va_high Yinghai Lu
2015-07-07 20:20 ` [PATCH 42/42] x86: fix msr print again Yinghai Lu
2015-07-07 23:21 ` [PATCH 00/42] x86: updated patches for kaslr and setup_data etc for v4.3 Kees Cook
2015-10-02 20:16 ` Kees Cook
2016-02-06 11:50 ` Baoquan He
2016-02-09 4:31 ` Kees Cook
2016-02-09 4:31 ` [kernel-hardening] " Kees Cook
2016-02-15 7:29 ` Baoquan He
2016-02-15 7:29 ` [kernel-hardening] " Baoquan He
2016-02-16 23:50 ` Kees Cook
2016-02-16 23:50 ` [kernel-hardening] " Kees Cook
2015-07-08 10:51 ` Ingo Molnar
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