x86-64: Directly access per-cpu IST
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(-)
arch/x86/kernel/entry_64.S +3 -3
@@ -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)
Signature · 1 line
1.7.2
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(-)
arch/x86/kernel/entry_32.S +5 -6
@@ -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
Signature · 1 line
1.7.2
[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(-)
arch/x86/kernel/entry_32.S +5 -6
@@ -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
[tip:x86/asm] x86-64, asm: Directly access per-cpu IST
In reply to Brian GerstCommit-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(-)
arch/x86/kernel/entry_64.S +3 -3
@@ -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)