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, Yinghai Lu <yinghai@kernel.org>
Subject: [PATCH 07/42] x86, boot: Move z_extract_offset calculation to header.S
Date: Tue, 7 Jul 2015 13:19:53 -0700 [thread overview]
Message-ID: <1436300428-21163-8-git-send-email-yinghai@kernel.org> (raw)
In-Reply-To: <1436300428-21163-1-git-send-email-yinghai@kernel.org>
Old extract_offset calculation is done without knowledge of decompressor size.
so it guess one big size.
We can move it to header.S, where we have exact decompressor size.
We save 8 pages for init_size with this patch.
before patch:
kernel: [13e000000,13fa1dfff]
input: [0x13f32d3b4-0x13fa01cc7], output: [0x13e000000-0x13f9ef81f], heap: [0x13fa0b680-0x13fa1367f]
after patch:
kernel: [13e000000,13fa15fff]
input: [0x13f3253b4-0x13f9f9cc7], output: [0x13e000000-0x13f9ef81f], heap: [0x13fa03680-0x13fa0b67f]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
---
arch/x86/boot/Makefile | 2 +-
arch/x86/boot/compressed/misc.c | 5 +----
arch/x86/boot/compressed/mkpiggy.c | 16 +---------------
| 29 +++++++++++++++++++++++++++++
4 files changed, 32 insertions(+), 20 deletions(-)
diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile
index 4d27e8b..e7196cf 100644
--- a/arch/x86/boot/Makefile
+++ b/arch/x86/boot/Makefile
@@ -77,7 +77,7 @@ $(obj)/vmlinux.bin: $(obj)/compressed/vmlinux FORCE
SETUP_OBJS = $(addprefix $(obj)/,$(setup-y))
-sed-zoffset := -e 's/^\([0-9a-fA-F]*\) [ABCDGRSTVW] \(startup_32\|startup_64\|efi32_stub_entry\|efi64_stub_entry\|efi_pe_entry\|input_data\|_end\|z_.*\)$$/\#define ZO_\2 0x\1/p'
+sed-zoffset := -e 's/^\([0-9a-fA-F]*\) [ABCDGRSTVW] \(startup_32\|startup_64\|efi32_stub_entry\|efi64_stub_entry\|efi_pe_entry\|input_data\|_end\|_ehead\|_text\|z_.*\)$$/\#define ZO_\2 0x\1/p'
quiet_cmd_zoffset = ZOFFSET $@
cmd_zoffset = $(NM) $< | sed -n $(sed-zoffset) > $@
diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
index 1c03098..db97bdf 100644
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -84,13 +84,10 @@
* To avoid problems with the compressed data's meta information an extra 18
* bytes are needed. Leading to the formula:
*
- * extra_bytes = (uncompressed_size >> 12) + 32768 + 18 + decompressor_size.
+ * extra_bytes = (uncompressed_size >> 12) + 32768 + 18.
*
* Adding 8 bytes per 32K is a bit excessive but much easier to calculate.
* Adding 32768 instead of 32767 just makes for round numbers.
- * Adding the decompressor_size is necessary as it musht live after all
- * of the data as well. Last I measured the decompressor is about 14K.
- * 10K of actual data and 4K of bss.
*
*/
diff --git a/arch/x86/boot/compressed/mkpiggy.c b/arch/x86/boot/compressed/mkpiggy.c
index c03b009..c5148642 100644
--- a/arch/x86/boot/compressed/mkpiggy.c
+++ b/arch/x86/boot/compressed/mkpiggy.c
@@ -21,8 +21,7 @@
* ----------------------------------------------------------------------- */
/*
- * Compute the desired load offset from a compressed program; outputs
- * a small assembly wrapper with the appropriate symbols defined.
+ * outputs a small assembly wrapper with the appropriate symbols defined.
*/
#include <stdlib.h>
@@ -35,7 +34,6 @@ int main(int argc, char *argv[])
{
uint32_t olen;
long ilen;
- unsigned long offs;
FILE *f = NULL;
int retval = 1;
@@ -65,23 +63,11 @@ int main(int argc, char *argv[])
ilen = ftell(f);
olen = get_unaligned_le32(&olen);
- /*
- * Now we have the input (compressed) and output (uncompressed)
- * sizes, compute the necessary decompression offset...
- */
-
- offs = (olen > ilen) ? olen - ilen : 0;
- offs += olen >> 12; /* Add 8 bytes for each 32K block */
- offs += 64*1024 + 128; /* Add 64K + 128 bytes slack */
- offs = (offs+4095) & ~4095; /* Round to a 4K boundary */
-
printf(".section \".rodata..compressed\",\"a\",@progbits\n");
printf(".globl z_input_len\n");
printf("z_input_len = %lu\n", ilen);
printf(".globl z_output_len\n");
printf("z_output_len = %lu\n", (unsigned long)olen);
- printf(".globl z_min_extract_offset\n");
- printf("z_min_extract_offset = 0x%lx\n", offs);
printf(".globl input_data, input_data_end\n");
printf("input_data:\n");
--git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
index 9bfab22..99204e5 100644
--- a/arch/x86/boot/header.S
+++ b/arch/x86/boot/header.S
@@ -440,7 +440,36 @@ setup_data: .quad 0 # 64-bit physical pointer to
pref_address: .quad LOAD_PHYSICAL_ADDR # preferred load addr
+/* check arch/x86/boot/compressed/misc.c for the formula about extra_bytes. */
+#define ZO_z_extra_bytes ((ZO_z_output_len >> 12) + 32768 + 18)
+#if ZO_z_output_len > ZO_z_input_len
+#define ZO_z_extract_offset (ZO_z_output_len + ZO_z_extra_bytes - ZO_z_input_len)
+#else
+#define ZO_z_extract_offset ZO_z_extra_bytes
+#endif
+
+/*
+ * extract_offset has to be bigger than ZO head section.
+ * otherwise during head code running to move ZO to end of buffer,
+ * will overwrite head code itself.
+ */
+#if (ZO__ehead - ZO_startup_32) > ZO_z_extract_offset
+#define ZO_z_min_extract_offset ((ZO__ehead - ZO_startup_32 + 4095) & ~4095)
+#else
+#define ZO_z_min_extract_offset ((ZO_z_extract_offset + 4095) & ~4095)
+#endif
+
#define ZO_INIT_SIZE (ZO__end - ZO_startup_32 + ZO_z_min_extract_offset)
+
+/*
+ * ZO__end - ZO_startup_32 is (ZO__ehead - ZO_startup_32) + ZO_z_input_len + (ZO__end - ZO__text)
+ * ZO_z_min_extract_offset >= (ZO_z_output_len + ZO_z_extra_bytes - ZO_z_input_len)
+ * then ZO_INIT_SIZE >= (ZO__ehead - ZO_startup_32) + ZO_z_input_len + (ZO__end - ZO__text) + (ZO_z_output_len + ZO_z_extra_bytes - ZO_z_input_len)
+ * so (ZO_INIT_SIZE - ZO_z_output_len) > (ZO__end - ZO__text)
+ * That means during decompressor running, output would not
+ * overwrite the decompressor itself.
+ */
+
#define VO_INIT_SIZE (VO__end - VO__text)
#if ZO_INIT_SIZE > VO_INIT_SIZE
#define INIT_SIZE ZO_INIT_SIZE
--
1.8.4.5
next prev parent reply other threads:[~2015-07-07 20:22 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 ` Yinghai Lu [this message]
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 ` [PATCH 17/42] x86, kaslr: Add support of kernel physical address randomization above 4G Yinghai Lu
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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