[PATCH] [26/26] i386: i386 separate hardware-defined TSS from Linux additions

From: Andi Kleen
Date: Sun Apr 29 2007 - 19:54:42 EST



From: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
On Thu, 2007-03-29 at 13:16 +0200, Andi Kleen wrote:
> Please clean it up properly with two structs.

Not sure about this, now I've done it. Running it here.

If you like it, I can do x86-64 as well.

==
lguest defines its own TSS struct because the "struct tss_struct"
contains linux-specific additions. Andi asked me to split the struct
in processor.h.

Unfortunately it makes usage a little awkward.

Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Signed-off-by: Andi Kleen <ak@xxxxxxx>

---
arch/i386/kernel/asm-offsets.c | 2 +-
arch/i386/kernel/doublefault.c | 31 +++++++++++++++++--------------
arch/i386/kernel/ioport.c | 2 +-
arch/i386/kernel/process.c | 8 ++++----
arch/i386/kernel/sysenter.c | 6 +++---
arch/i386/kernel/traps.c | 4 ++--
arch/i386/kernel/vmi.c | 8 ++++----
include/asm-i386/processor.h | 24 ++++++++++++++++--------
8 files changed, 48 insertions(+), 37 deletions(-)

Index: linux/include/asm-i386/processor.h
===================================================================
--- linux.orig/include/asm-i386/processor.h
+++ linux/include/asm-i386/processor.h
@@ -291,7 +291,8 @@ typedef struct {

struct thread_struct;

-struct tss_struct {
+/* This is the TSS defined by the hardware. */
+struct i386_hw_tss {
unsigned short back_link,__blh;
unsigned long esp0;
unsigned short ss0,__ss0h;
@@ -315,6 +316,11 @@ struct tss_struct {
unsigned short gs, __gsh;
unsigned short ldt, __ldth;
unsigned short trace, io_bitmap_base;
+} __attribute__((packed));
+
+struct tss_struct {
+ struct i386_hw_tss x86_tss;
+
/*
* The extra 1 is there because the CPU will access an
* additional byte beyond the end of the IO permission
@@ -381,10 +387,12 @@ struct thread_struct {
* be within the limit.
*/
#define INIT_TSS { \
- .esp0 = sizeof(init_stack) + (long)&init_stack, \
- .ss0 = __KERNEL_DS, \
- .ss1 = __KERNEL_CS, \
- .io_bitmap_base = INVALID_IO_BITMAP_OFFSET, \
+ .x86_tss = { \
+ .esp0 = sizeof(init_stack) + (long)&init_stack, \
+ .ss0 = __KERNEL_DS, \
+ .ss1 = __KERNEL_CS, \
+ .io_bitmap_base = INVALID_IO_BITMAP_OFFSET, \
+ }, \
.io_bitmap = { [ 0 ... IO_BITMAP_LONGS] = ~0 }, \
}

@@ -493,10 +501,10 @@ static inline void rep_nop(void)

static inline void native_load_esp0(struct tss_struct *tss, struct thread_struct *thread)
{
- tss->esp0 = thread->esp0;
+ tss->x86_tss.esp0 = thread->esp0;
/* This can only happen when SEP is enabled, no need to test "SEP"arately */
- if (unlikely(tss->ss1 != thread->sysenter_cs)) {
- tss->ss1 = thread->sysenter_cs;
+ if (unlikely(tss->x86_tss.ss1 != thread->sysenter_cs)) {
+ tss->x86_tss.ss1 = thread->sysenter_cs;
wrmsr(MSR_IA32_SYSENTER_CS, thread->sysenter_cs, 0);
}
}
Index: linux/arch/i386/kernel/asm-offsets.c
===================================================================
--- linux.orig/arch/i386/kernel/asm-offsets.c
+++ linux/arch/i386/kernel/asm-offsets.c
@@ -93,7 +93,7 @@ void foo(void)
OFFSET(pbe_next, pbe, next);

/* Offset from the sysenter stack to tss.esp0 */
- DEFINE(TSS_sysenter_esp0, offsetof(struct tss_struct, esp0) -
+ DEFINE(TSS_sysenter_esp0, offsetof(struct tss_struct, x86_tss.esp0) -
sizeof(struct tss_struct));

DEFINE(PAGE_SIZE_asm, PAGE_SIZE);
Index: linux/arch/i386/kernel/doublefault.c
===================================================================
--- linux.orig/arch/i386/kernel/doublefault.c
+++ linux/arch/i386/kernel/doublefault.c
@@ -33,7 +33,7 @@ static void doublefault_fn(void)
printk("double fault, tss at %08lx\n", tss);

if (ptr_ok(tss)) {
- struct tss_struct *t = (struct tss_struct *)tss;
+ struct i386_hw_tss *t = (struct i386_hw_tss *)tss;

printk("eip = %08lx, esp = %08lx\n", t->eip, t->esp);

@@ -49,18 +49,21 @@ static void doublefault_fn(void)
}

struct tss_struct doublefault_tss __cacheline_aligned = {
- .esp0 = STACK_START,
- .ss0 = __KERNEL_DS,
- .ldt = 0,
- .io_bitmap_base = INVALID_IO_BITMAP_OFFSET,
-
- .eip = (unsigned long) doublefault_fn,
- .eflags = X86_EFLAGS_SF | 0x2, /* 0x2 bit is always set */
- .esp = STACK_START,
- .es = __USER_DS,
- .cs = __KERNEL_CS,
- .ss = __KERNEL_DS,
- .ds = __USER_DS,
+ .x86_tss = {
+ .esp0 = STACK_START,
+ .ss0 = __KERNEL_DS,
+ .ldt = 0,
+ .io_bitmap_base = INVALID_IO_BITMAP_OFFSET,
+
+ .eip = (unsigned long) doublefault_fn,
+ /* 0x2 bit is always set */
+ .eflags = X86_EFLAGS_SF | 0x2,
+ .esp = STACK_START,
+ .es = __USER_DS,
+ .cs = __KERNEL_CS,
+ .ss = __KERNEL_DS,
+ .ds = __USER_DS,

- .__cr3 = __pa(swapper_pg_dir)
+ .__cr3 = __pa(swapper_pg_dir)
+ }
};
Index: linux/arch/i386/kernel/ioport.c
===================================================================
--- linux.orig/arch/i386/kernel/ioport.c
+++ linux/arch/i386/kernel/ioport.c
@@ -114,7 +114,7 @@ asmlinkage long sys_ioperm(unsigned long
* Reset the owner so that a process switch will not set
* tss->io_bitmap_base to IO_BITMAP_OFFSET.
*/
- tss->io_bitmap_base = INVALID_IO_BITMAP_OFFSET_LAZY;
+ tss->x86_tss.io_bitmap_base = INVALID_IO_BITMAP_OFFSET_LAZY;
tss->io_bitmap_owner = NULL;

put_cpu();
Index: linux/arch/i386/kernel/process.c
===================================================================
--- linux.orig/arch/i386/kernel/process.c
+++ linux/arch/i386/kernel/process.c
@@ -375,7 +375,7 @@ void exit_thread(void)
t->io_bitmap_max = 0;
tss->io_bitmap_owner = NULL;
tss->io_bitmap_max = 0;
- tss->io_bitmap_base = INVALID_IO_BITMAP_OFFSET;
+ tss->x86_tss.io_bitmap_base = INVALID_IO_BITMAP_OFFSET;
put_cpu();
}
}
@@ -554,7 +554,7 @@ static noinline void __switch_to_xtra(st
* Disable the bitmap via an invalid offset. We still cache
* the previous bitmap owner and the IO bitmap contents:
*/
- tss->io_bitmap_base = INVALID_IO_BITMAP_OFFSET;
+ tss->x86_tss.io_bitmap_base = INVALID_IO_BITMAP_OFFSET;
return;
}

@@ -564,7 +564,7 @@ static noinline void __switch_to_xtra(st
* matches the next task, we dont have to do anything but
* to set a valid offset in the TSS:
*/
- tss->io_bitmap_base = IO_BITMAP_OFFSET;
+ tss->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET;
return;
}
/*
@@ -576,7 +576,7 @@ static noinline void __switch_to_xtra(st
* redundant copies when the currently switched task does not
* perform any I/O during its timeslice.
*/
- tss->io_bitmap_base = INVALID_IO_BITMAP_OFFSET_LAZY;
+ tss->x86_tss.io_bitmap_base = INVALID_IO_BITMAP_OFFSET_LAZY;
}

/*
Index: linux/arch/i386/kernel/sysenter.c
===================================================================
--- linux.orig/arch/i386/kernel/sysenter.c
+++ linux/arch/i386/kernel/sysenter.c
@@ -183,10 +183,10 @@ void enable_sep_cpu(void)
return;
}

- tss->ss1 = __KERNEL_CS;
- tss->esp1 = sizeof(struct tss_struct) + (unsigned long) tss;
+ tss->x86_tss.ss1 = __KERNEL_CS;
+ tss->x86_tss.esp1 = sizeof(struct tss_struct) + (unsigned long) tss;
wrmsr(MSR_IA32_SYSENTER_CS, __KERNEL_CS, 0);
- wrmsr(MSR_IA32_SYSENTER_ESP, tss->esp1, 0);
+ wrmsr(MSR_IA32_SYSENTER_ESP, tss->x86_tss.esp1, 0);
wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long) sysenter_entry, 0);
put_cpu();
}
Index: linux/arch/i386/kernel/traps.c
===================================================================
--- linux.orig/arch/i386/kernel/traps.c
+++ linux/arch/i386/kernel/traps.c
@@ -596,7 +596,7 @@ fastcall void __kprobes do_general_prote
* and we set the offset field correctly. Then we let the CPU to
* restart the faulting instruction.
*/
- if (tss->io_bitmap_base == INVALID_IO_BITMAP_OFFSET_LAZY &&
+ if (tss->x86_tss.io_bitmap_base == INVALID_IO_BITMAP_OFFSET_LAZY &&
thread->io_bitmap_ptr) {
memcpy(tss->io_bitmap, thread->io_bitmap_ptr,
thread->io_bitmap_max);
@@ -609,7 +609,7 @@ fastcall void __kprobes do_general_prote
thread->io_bitmap_max, 0xff,
tss->io_bitmap_max - thread->io_bitmap_max);
tss->io_bitmap_max = thread->io_bitmap_max;
- tss->io_bitmap_base = IO_BITMAP_OFFSET;
+ tss->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET;
tss->io_bitmap_owner = thread;
put_cpu();
return;
Index: linux/arch/i386/kernel/vmi.c
===================================================================
--- linux.orig/arch/i386/kernel/vmi.c
+++ linux/arch/i386/kernel/vmi.c
@@ -230,14 +230,14 @@ static void vmi_set_tr(void)
static void vmi_load_esp0(struct tss_struct *tss,
struct thread_struct *thread)
{
- tss->esp0 = thread->esp0;
+ tss->x86_tss.esp0 = thread->esp0;

/* This can only happen when SEP is enabled, no need to test "SEP"arately */
- if (unlikely(tss->ss1 != thread->sysenter_cs)) {
- tss->ss1 = thread->sysenter_cs;
+ if (unlikely(tss->x86_tss.ss1 != thread->sysenter_cs)) {
+ tss->x86_tss.ss1 = thread->sysenter_cs;
wrmsr(MSR_IA32_SYSENTER_CS, thread->sysenter_cs, 0);
}
- vmi_ops.set_kernel_stack(__KERNEL_DS, tss->esp0);
+ vmi_ops.set_kernel_stack(__KERNEL_DS, tss->x86_tss.esp0);
}

static void vmi_flush_tlb_user(void)
-
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