From: Anders Kaseorg <[email protected]>
Previously, the address of the vsyscall page (VSYSCALL_PHYS_ADDR,
VSYSCALL_VIRT_ADDR) was computed by arithmetic on the address of the
last section. This leads to bugs when new sections are inserted, such
as the one fixed by commit d312ceda567ab91acd756cde95ac5fbc6b40ed40.
Let's compute it from the current address instead.
Signed-off-by: Anders Kaseorg <[email protected]>
Signed-off-by: Tim Abbott <[email protected]>
---
arch/x86/kernel/vmlinux.lds.S | 19 +++++++------------
1 files changed, 7 insertions(+), 12 deletions(-)
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 9fc1782..e771251 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -135,24 +135,21 @@ SECTIONS
#ifdef CONFIG_X86_64
#define VSYSCALL_ADDR (-10*1024*1024)
-#define VSYSCALL_PHYS_ADDR ((LOADADDR(.data) + SIZEOF(.data) + \
- PAGE_SIZE - 1) & ~(PAGE_SIZE - 1))
-#define VSYSCALL_VIRT_ADDR ((ADDR(.data) + SIZEOF(.data) + \
- PAGE_SIZE - 1) & ~(PAGE_SIZE - 1))
-#define VLOAD_OFFSET (VSYSCALL_ADDR - VSYSCALL_PHYS_ADDR)
+#define VLOAD_OFFSET (VSYSCALL_ADDR - __vsyscall_0 + LOAD_OFFSET)
#define VLOAD(x) (ADDR(x) - VLOAD_OFFSET)
-#define VVIRT_OFFSET (VSYSCALL_ADDR - VSYSCALL_VIRT_ADDR)
+#define VVIRT_OFFSET (VSYSCALL_ADDR - __vsyscall_0)
#define VVIRT(x) (ADDR(x) - VVIRT_OFFSET)
+ . = ALIGN(4096);
+ __vsyscall_0 = .;
+
. = VSYSCALL_ADDR;
- .vsyscall_0 : AT(VSYSCALL_PHYS_ADDR) {
+ .vsyscall_0 : AT(VLOAD(.vsyscall_0)) {
*(.vsyscall_0)
} :user
- __vsyscall_0 = VSYSCALL_VIRT_ADDR;
-
. = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
.vsyscall_fn : AT(VLOAD(.vsyscall_fn)) {
*(.vsyscall_fn)
@@ -192,11 +189,9 @@ SECTIONS
*(.vsyscall_3)
}
- . = VSYSCALL_VIRT_ADDR + PAGE_SIZE;
+ . = __vsyscall_0 + PAGE_SIZE;
#undef VSYSCALL_ADDR
-#undef VSYSCALL_PHYS_ADDR
-#undef VSYSCALL_VIRT_ADDR
#undef VLOAD_OFFSET
#undef VLOAD
#undef VVIRT_OFFSET
--
1.6.3.3
This has the consequence of changing the section name use for head
code from ".text.head" to ".head.text".
Linus suggested that we merge the ".text.head" section with ".text"
(presumably while preserving the fact that the head code starts at 0).
When I tried this it caused the kernel to not boot.
Signed-off-by: Tim Abbott <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Sam Ravnborg <[email protected]>
Cc: Linus Torvalds <[email protected]>
---
arch/x86/boot/compressed/head_32.S | 3 ++-
arch/x86/boot/compressed/head_64.S | 3 ++-
arch/x86/boot/compressed/vmlinux.lds.S | 6 ++++--
3 files changed, 8 insertions(+), 4 deletions(-)
diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S
index 75e4f00..f543b70 100644
--- a/arch/x86/boot/compressed/head_32.S
+++ b/arch/x86/boot/compressed/head_32.S
@@ -23,13 +23,14 @@
*/
.text
+#include <linux/init.h>
#include <linux/linkage.h>
#include <asm/segment.h>
#include <asm/page_types.h>
#include <asm/boot.h>
#include <asm/asm-offsets.h>
- .section ".text.head","ax",@progbits
+ __HEAD
ENTRY(startup_32)
cld
/*
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index f62c284..077e1b6 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -24,6 +24,7 @@
.code32
.text
+#include <linux/init.h>
#include <linux/linkage.h>
#include <asm/segment.h>
#include <asm/pgtable_types.h>
@@ -33,7 +34,7 @@
#include <asm/processor-flags.h>
#include <asm/asm-offsets.h>
- .section ".text.head"
+ __HEAD
.code32
ENTRY(startup_32)
cld
diff --git a/arch/x86/boot/compressed/vmlinux.lds.S b/arch/x86/boot/compressed/vmlinux.lds.S
index cc353e1..f4193bb 100644
--- a/arch/x86/boot/compressed/vmlinux.lds.S
+++ b/arch/x86/boot/compressed/vmlinux.lds.S
@@ -1,3 +1,5 @@
+#include <asm-generic/vmlinux.lds.h>
+
OUTPUT_FORMAT(CONFIG_OUTPUT_FORMAT, CONFIG_OUTPUT_FORMAT, CONFIG_OUTPUT_FORMAT)
#undef i386
@@ -18,9 +20,9 @@ SECTIONS
* address 0.
*/
. = 0;
- .text.head : {
+ .head.text : {
_head = . ;
- *(.text.head)
+ HEAD_TEXT
_ehead = . ;
}
.rodata.compressed : {
--
1.6.3.3
This has the consequence of changing the section name use for head
code from ".text.head" to ".head.text". It also eliminates the
".text.head" output section (instead placing head code at the start of
the .text output section), which should be harmless.
This patch only changes the sections in the actual kernel, not those
in the compressed boot loader.
Signed-off-by: Tim Abbott <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Sam Ravnborg <[email protected]>
---
arch/x86/kernel/head_32.S | 2 +-
arch/x86/kernel/head_64.S | 2 +-
arch/x86/kernel/vmlinux.lds.S | 12 +++---------
3 files changed, 5 insertions(+), 11 deletions(-)
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index 3eba3ab..f689c31 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -79,7 +79,7 @@ RESERVE_BRK(pagetables, INIT_MAP_SIZE)
* any particular GDT layout, because we load our own as soon as we
* can.
*/
-.section .text.head,"ax",@progbits
+__HEAD
ENTRY(startup_32)
/* test KEEP_SEGMENTS flag to see if the bootloader is asking
us to not reload segments */
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index d0bc0a1..780cd92 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -40,7 +40,7 @@ L4_START_KERNEL = pgd_index(__START_KERNEL_map)
L3_START_KERNEL = pud_index(__START_KERNEL_map)
.text
- .section .text.head
+ __HEAD
.code64
.globl startup_64
startup_64:
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index e771251..51a8478 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -65,17 +65,11 @@ SECTIONS
#endif
/* Text and read-only data */
-
- /* bootstrapping code */
- .text.head : AT(ADDR(.text.head) - LOAD_OFFSET) {
- _text = .;
- *(.text.head)
- } :text = 0x9090
-
- /* The rest of the text */
.text : AT(ADDR(.text) - LOAD_OFFSET) {
+ _text = .;
+ /* bootstrapping code */
+ HEAD_TEXT
#ifdef CONFIG_X86_32
- /* not really needed, already page aligned */
. = ALIGN(PAGE_SIZE);
*(.text.page_aligned)
#endif
--
1.6.3.3
The .data.idt section is just squashed into the .data.page_aligned
output section by the linker script anyway, so it might as well be in
the .data.page_aligned section.
This eliminates all references to .data.idt on x86.
Signed-off-by: Tim Abbott <[email protected]>
Cc: Ingo Molnar <[email protected]>
---
arch/x86/kernel/traps.c | 6 ++----
arch/x86/kernel/vmlinux.lds.S | 1 -
2 files changed, 2 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 5204332..dd04f86 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -73,11 +73,9 @@ char ignore_fpu_irq;
/*
* The IDT has to be page-aligned to simplify the Pentium
- * F0 0F bug workaround.. We have a special link segment
- * for this.
+ * F0 0F bug workaround.
*/
-gate_desc idt_table[256]
- __attribute__((__section__(".data.idt"))) = { { { { 0, 0 } } }, };
+gate_desc idt_table[256] __page_aligned_data = { { { { 0, 0 } } }, };
#endif
DECLARE_BITMAP(used_vectors, NR_VECTORS);
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 51a8478..dad5a59 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -112,7 +112,6 @@ SECTIONS
#endif
PAGE_ALIGNED_DATA(PAGE_SIZE)
- *(.data.idt)
CACHELINE_ALIGNED_DATA(CONFIG_X86_L1_CACHE_BYTES)
--
1.6.3.3
Signed-off-by: Tim Abbott <[email protected]>
---
arch/x86/kernel/vmlinux.lds.S | 47 ++--------------------------------------
1 files changed, 3 insertions(+), 44 deletions(-)
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index dad5a59..eae79d3 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -88,13 +88,7 @@ SECTIONS
NOTES :text :note
- /* Exception table */
- . = ALIGN(16);
- __ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) {
- __start___ex_table = .;
- *(__ex_table)
- __stop___ex_table = .;
- } :text = 0x9090
+ EXCEPTION_TABLE(16) :text = 0x9090
RO_DATA(PAGE_SIZE)
@@ -207,36 +201,12 @@ SECTIONS
PERCPU_VADDR(0, :percpu)
#endif
- .init.text : AT(ADDR(.init.text) - LOAD_OFFSET) {
- _sinittext = .;
- INIT_TEXT
- _einittext = .;
- }
+ INIT_TEXT_SECTION(PAGE_SIZE)
#ifdef CONFIG_X86_64
:init
#endif
- .init.data : AT(ADDR(.init.data) - LOAD_OFFSET) {
- INIT_DATA
- }
-
- . = ALIGN(16);
- .init.setup : AT(ADDR(.init.setup) - LOAD_OFFSET) {
- __setup_start = .;
- *(.init.setup)
- __setup_end = .;
- }
- .initcall.init : AT(ADDR(.initcall.init) - LOAD_OFFSET) {
- __initcall_start = .;
- INITCALLS
- __initcall_end = .;
- }
-
- .con_initcall.init : AT(ADDR(.con_initcall.init) - LOAD_OFFSET) {
- __con_initcall_start = .;
- *(.con_initcall.init)
- __con_initcall_end = .;
- }
+ INIT_DATA_SECTION(16)
.x86_cpu_dev.init : AT(ADDR(.x86_cpu_dev.init) - LOAD_OFFSET) {
__x86_cpu_dev_start = .;
@@ -244,8 +214,6 @@ SECTIONS
__x86_cpu_dev_end = .;
}
- SECURITY_INIT
-
. = ALIGN(8);
.parainstructions : AT(ADDR(.parainstructions) - LOAD_OFFSET) {
__parainstructions = .;
@@ -276,15 +244,6 @@ SECTIONS
EXIT_DATA
}
-#ifdef CONFIG_BLK_DEV_INITRD
- . = ALIGN(PAGE_SIZE);
- .init.ramfs : AT(ADDR(.init.ramfs) - LOAD_OFFSET) {
- __initramfs_start = .;
- *(.init.ramfs)
- __initramfs_end = .;
- }
-#endif
-
#if !defined(CONFIG_X86_64) || !defined(CONFIG_SMP)
PERCPU(PAGE_SIZE)
#endif
--
1.6.3.3