2010-07-31 16:48:32

by Brian Gerst

Subject: [PATCH 1/2] x86-64: Directly access per-cpu IST

Use a direct per-cpu reference for the IST instead of using a scratch
register.

Signed-off-by: Brian Gerst <[email protected]>
---
arch/x86/kernel/entry_64.S | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 4db7c4d..59af275 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -1065,6 +1065,7 @@ ENTRY(\sym)
END(\sym)
.endm

+#define INIT_TSS_IST(x) PER_CPU_VAR(init_tss) + (TSS_ist + ((x) - 1) * 8)
.macro paranoidzeroentry_ist sym do_sym ist
ENTRY(\sym)
INTR_FRAME
@@ -1076,10 +1077,9 @@ ENTRY(\sym)
TRACE_IRQS_OFF
movq %rsp,%rdi /* pt_regs pointer */
xorl %esi,%esi /* no error code */
- PER_CPU(init_tss, %r12)
- subq $EXCEPTION_STKSZ, TSS_ist + (\ist - 1) * 8(%r12)
+ subq $EXCEPTION_STKSZ, INIT_TSS_IST(\ist)
call \do_sym
- addq $EXCEPTION_STKSZ, TSS_ist + (\ist - 1) * 8(%r12)
+ addq $EXCEPTION_STKSZ, INIT_TSS_IST(\ist)
jmp paranoid_exit /* %ebx: no swapgs flag */
CFI_ENDPROC
END(\sym)
--
1.7.2

2010-07-31 16:48:39

by Brian Gerst

Subject: [PATCH 2/2] x86-32: Directly access per-cpu GDT

Use a direct per-cpu reference for the GDT instead of using a scratch
register.

Signed-off-by: Brian Gerst <[email protected]>
---
arch/x86/kernel/entry_32.S | 11 +++++------
1 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index cd49141..233c582 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -611,14 +611,14 @@ ldt_ss:
* compensating for the offset by changing to the ESPFIX segment with
* a base address that matches for the difference.
*/
+#define GDT_ESPFIX_SS PER_CPU_VAR(gdt_page) + (GDT_ENTRY_ESPFIX_SS * 8)
mov %esp, %edx /* load kernel esp */
mov PT_OLDESP(%esp), %eax /* load userspace esp */
mov %dx, %ax /* eax: new kernel esp */
sub %eax, %edx /* offset (low word is 0) */
- PER_CPU(gdt_page, %ebx)
shr $16, %edx
- mov %dl, GDT_ENTRY_ESPFIX_SS * 8 + 4(%ebx) /* bits 16..23 */
- mov %dh, GDT_ENTRY_ESPFIX_SS * 8 + 7(%ebx) /* bits 24..31 */
+ mov %dl, GDT_ESPFIX_SS + 4 /* bits 16..23 */
+ mov %dh, GDT_ESPFIX_SS + 7 /* bits 24..31 */
pushl $__ESPFIX_SS
CFI_ADJUST_CFA_OFFSET 4
push %eax /* new kernel esp */
@@ -791,9 +791,8 @@ ptregs_clone:
* normal stack and adjusts ESP with the matching offset.
*/
/* fixup the stack */
- PER_CPU(gdt_page, %ebx)
- mov GDT_ENTRY_ESPFIX_SS * 8 + 4(%ebx), %al /* bits 16..23 */
- mov GDT_ENTRY_ESPFIX_SS * 8 + 7(%ebx), %ah /* bits 24..31 */
+ mov GDT_ESPFIX_SS + 4, %al /* bits 16..23 */
+ mov GDT_ESPFIX_SS + 7, %ah /* bits 24..31 */
shl $16, %eax
addl %esp, %eax /* the adjusted stack pointer */
pushl $__KERNEL_DS
--
1.7.2

2010-08-02 15:16:13

by Brian Gerst

Subject: [tip:x86/asm] x86-64, asm: Directly access per-cpu IST

Commit-ID: c15a5958a0b6dbf06b3c05972694f04a0c50a4cf
Gitweb: http://git.kernel.org/tip/c15a5958a0b6dbf06b3c05972694f04a0c50a4cf
Author: Brian Gerst <[email protected]>
AuthorDate: Sat, 31 Jul 2010 12:48:22 -0400
Committer: H. Peter Anvin <[email protected]>
CommitDate: Sun, 1 Aug 2010 16:05:17 -0700

x86-64, asm: Directly access per-cpu IST

Use a direct per-cpu reference for the IST instead of using a scratch
register.

Signed-off-by: Brian Gerst <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: H. Peter Anvin <[email protected]>
---
arch/x86/kernel/entry_64.S | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 4db7c4d..59af275 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -1065,6 +1065,7 @@ ENTRY(\sym)
END(\sym)
.endm

+#define INIT_TSS_IST(x) PER_CPU_VAR(init_tss) + (TSS_ist + ((x) - 1) * 8)
.macro paranoidzeroentry_ist sym do_sym ist
ENTRY(\sym)
INTR_FRAME
@@ -1076,10 +1077,9 @@ ENTRY(\sym)
TRACE_IRQS_OFF
movq %rsp,%rdi /* pt_regs pointer */
xorl %esi,%esi /* no error code */
- PER_CPU(init_tss, %r12)
- subq $EXCEPTION_STKSZ, TSS_ist + (\ist - 1) * 8(%r12)
+ subq $EXCEPTION_STKSZ, INIT_TSS_IST(\ist)
call \do_sym
- addq $EXCEPTION_STKSZ, TSS_ist + (\ist - 1) * 8(%r12)
+ addq $EXCEPTION_STKSZ, INIT_TSS_IST(\ist)
jmp paranoid_exit /* %ebx: no swapgs flag */
CFI_ENDPROC
END(\sym)

2010-08-02 15:16:30

by Brian Gerst

Subject: [tip:x86/asm] x86-32, asm: Directly access per-cpu GDT

Commit-ID: 72c511dd596cff88d6523f231a0fbb8f73006d51
Gitweb: http://git.kernel.org/tip/72c511dd596cff88d6523f231a0fbb8f73006d51
Author: Brian Gerst <[email protected]>
AuthorDate: Sat, 31 Jul 2010 12:48:23 -0400
Committer: H. Peter Anvin <[email protected]>
CommitDate: Sun, 1 Aug 2010 16:05:23 -0700

x86-32, asm: Directly access per-cpu GDT

Use a direct per-cpu reference for the GDT instead of using a scratch
register.

Signed-off-by: Brian Gerst <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: H. Peter Anvin <[email protected]>
---
arch/x86/kernel/entry_32.S | 11 +++++------
1 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index cd49141..233c582 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -611,14 +611,14 @@ ldt_ss:
* compensating for the offset by changing to the ESPFIX segment with
* a base address that matches for the difference.
*/
+#define GDT_ESPFIX_SS PER_CPU_VAR(gdt_page) + (GDT_ENTRY_ESPFIX_SS * 8)
mov %esp, %edx /* load kernel esp */
mov PT_OLDESP(%esp), %eax /* load userspace esp */
mov %dx, %ax /* eax: new kernel esp */
sub %eax, %edx /* offset (low word is 0) */
- PER_CPU(gdt_page, %ebx)
shr $16, %edx
- mov %dl, GDT_ENTRY_ESPFIX_SS * 8 + 4(%ebx) /* bits 16..23 */
- mov %dh, GDT_ENTRY_ESPFIX_SS * 8 + 7(%ebx) /* bits 24..31 */
+ mov %dl, GDT_ESPFIX_SS + 4 /* bits 16..23 */
+ mov %dh, GDT_ESPFIX_SS + 7 /* bits 24..31 */
pushl $__ESPFIX_SS
CFI_ADJUST_CFA_OFFSET 4
push %eax /* new kernel esp */
@@ -791,9 +791,8 @@ ptregs_clone:
* normal stack and adjusts ESP with the matching offset.
*/
/* fixup the stack */
- PER_CPU(gdt_page, %ebx)
- mov GDT_ENTRY_ESPFIX_SS * 8 + 4(%ebx), %al /* bits 16..23 */
- mov GDT_ENTRY_ESPFIX_SS * 8 + 7(%ebx), %ah /* bits 24..31 */
+ mov GDT_ESPFIX_SS + 4, %al /* bits 16..23 */
+ mov GDT_ESPFIX_SS + 7, %ah /* bits 24..31 */
shl $16, %eax
addl %esp, %eax /* the adjusted stack pointer */
pushl $__KERNEL_DS