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-rw-r--r--arch/x86/include/asm/desc.h26
-rw-r--r--arch/x86/include/asm/msr.h7
-rw-r--r--arch/x86/kernel/apic/io_apic.c4
-rw-r--r--arch/x86/kernel/apic/probe_32.c11
-rw-r--r--arch/x86/kernel/apic/summit_32.c1
-rw-r--r--arch/x86/kernel/cpu/common.c2
-rw-r--r--arch/x86/kernel/entry_32.S64
-rw-r--r--arch/x86/kernel/head_32.S1
-rw-r--r--arch/x86/kernel/head_64.S1
9 files changed, 47 insertions, 70 deletions
diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h
index c45f415..c993e9e 100644
--- a/arch/x86/include/asm/desc.h
+++ b/arch/x86/include/asm/desc.h
@@ -1,7 +1,6 @@
#ifndef _ASM_X86_DESC_H
#define _ASM_X86_DESC_H
-#ifndef __ASSEMBLY__
#include <asm/desc_defs.h>
#include <asm/ldt.h>
#include <asm/mmu.h>
@@ -380,29 +379,4 @@ static inline void set_system_intr_gate_ist(int n, void *addr, unsigned ist)
_set_gate(n, GATE_INTERRUPT, addr, 0x3, ist, __KERNEL_CS);
}
-#else
-/*
- * GET_DESC_BASE reads the descriptor base of the specified segment.
- *
- * Args:
- * idx - descriptor index
- * gdt - GDT pointer
- * base - 32bit register to which the base will be written
- * lo_w - lo word of the "base" register
- * lo_b - lo byte of the "base" register
- * hi_b - hi byte of the low word of the "base" register
- *
- * Example:
- * GET_DESC_BASE(GDT_ENTRY_ESPFIX_SS, %ebx, %eax, %ax, %al, %ah)
- * Will read the base address of GDT_ENTRY_ESPFIX_SS and put it into %eax.
- */
-#define GET_DESC_BASE(idx, gdt, base, lo_w, lo_b, hi_b) \
- movb idx * 8 + 4(gdt), lo_b; \
- movb idx * 8 + 7(gdt), hi_b; \
- shll $16, base; \
- movw idx * 8 + 2(gdt), lo_w;
-
-
-#endif /* __ASSEMBLY__ */
-
#endif /* _ASM_X86_DESC_H */
diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h
index 2260376..48ad9d2 100644
--- a/arch/x86/include/asm/msr.h
+++ b/arch/x86/include/asm/msr.h
@@ -3,13 +3,10 @@
#include <asm/msr-index.h>
-#ifndef __ASSEMBLY__
-# include <linux/types.h>
-#endif
-
#ifdef __KERNEL__
#ifndef __ASSEMBLY__
+#include <linux/types.h>
#include <asm/asm.h>
#include <asm/errno.h>
#include <asm/cpumask.h>
@@ -264,6 +261,4 @@ static inline int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
#endif /* CONFIG_SMP */
#endif /* __ASSEMBLY__ */
#endif /* __KERNEL__ */
-
-
#endif /* _ASM_X86_MSR_H */
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 29d0752..b7a7920 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -2004,7 +2004,9 @@ void disable_IO_APIC(void)
/*
* Use virtual wire A mode when interrupt remapping is enabled.
*/
- disconnect_bsp_APIC(!intr_remapping_enabled && ioapic_i8259.pin != -1);
+ if (cpu_has_apic)
+ disconnect_bsp_APIC(!intr_remapping_enabled &&
+ ioapic_i8259.pin != -1);
}
#ifdef CONFIG_X86_32
diff --git a/arch/x86/kernel/apic/probe_32.c b/arch/x86/kernel/apic/probe_32.c
index 440a8bc..0c0182c 100644
--- a/arch/x86/kernel/apic/probe_32.c
+++ b/arch/x86/kernel/apic/probe_32.c
@@ -20,23 +20,12 @@
#include <asm/apic.h>
#include <asm/setup.h>
-#include <linux/threads.h>
-#include <linux/cpumask.h>
-#include <asm/mpspec.h>
-#include <asm/fixmap.h>
-#include <asm/apicdef.h>
-#include <linux/kernel.h>
-#include <linux/string.h>
#include <linux/smp.h>
-#include <linux/init.h>
#include <asm/ipi.h>
-#include <linux/smp.h>
-#include <linux/init.h>
#include <linux/interrupt.h>
#include <asm/acpi.h>
#include <asm/e820.h>
-#include <asm/setup.h>
#ifdef CONFIG_HOTPLUG_CPU
#define DEFAULT_SEND_IPI (1)
diff --git a/arch/x86/kernel/apic/summit_32.c b/arch/x86/kernel/apic/summit_32.c
index 344eee4..eafdfbd1 100644
--- a/arch/x86/kernel/apic/summit_32.c
+++ b/arch/x86/kernel/apic/summit_32.c
@@ -44,7 +44,6 @@
#include <asm/ipi.h>
#include <linux/kernel.h>
#include <linux/string.h>
-#include <linux/init.h>
#include <linux/gfp.h>
#include <linux/smp.h>
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 5b9cb88..ba1131a 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -108,7 +108,7 @@ DEFINE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page) = { .gdt = {
/* data */
[GDT_ENTRY_APMBIOS_BASE+2] = { { { 0x0000ffff, 0x00409200 } } },
- [GDT_ENTRY_ESPFIX_SS] = { { { 0x00000000, 0x00c09200 } } },
+ [GDT_ENTRY_ESPFIX_SS] = { { { 0x0000ffff, 0x00cf9200 } } },
[GDT_ENTRY_PERCPU] = { { { 0x0000ffff, 0x00cf9200 } } },
GDT_STACK_CANARY_INIT
#endif
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index c929add..9f8ce77 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -48,7 +48,6 @@
#include <asm/segment.h>
#include <asm/smp.h>
#include <asm/page_types.h>
-#include <asm/desc.h>
#include <asm/percpu.h>
#include <asm/dwarf2.h>
#include <asm/processor-flags.h>
@@ -84,7 +83,7 @@
#define preempt_stop(clobbers) DISABLE_INTERRUPTS(clobbers); TRACE_IRQS_OFF
#else
#define preempt_stop(clobbers)
-#define resume_kernel restore_nocheck
+#define resume_kernel restore_all
#endif
.macro TRACE_IRQS_IRET
@@ -372,7 +371,7 @@ END(ret_from_exception)
ENTRY(resume_kernel)
DISABLE_INTERRUPTS(CLBR_ANY)
cmpl $0,TI_preempt_count(%ebp) # non-zero preempt_count ?
- jnz restore_nocheck
+ jnz restore_all
need_resched:
movl TI_flags(%ebp), %ecx # need_resched set ?
testb $_TIF_NEED_RESCHED, %cl
@@ -540,6 +539,8 @@ syscall_exit:
jne syscall_exit_work
restore_all:
+ TRACE_IRQS_IRET
+restore_all_notrace:
movl PT_EFLAGS(%esp), %eax # mix EFLAGS, SS and CS
# Warning: PT_OLDSS(%esp) contains the wrong/random values if we
# are returning to the kernel.
@@ -551,8 +552,6 @@ restore_all:
CFI_REMEMBER_STATE
je ldt_ss # returning to user-space with LDT SS
restore_nocheck:
- TRACE_IRQS_IRET
-restore_nocheck_notrace:
RESTORE_REGS 4 # skip orig_eax/error_code
CFI_ADJUST_CFA_OFFSET -4
irq_return:
@@ -588,22 +587,34 @@ ldt_ss:
jne restore_nocheck
#endif
- /* If returning to userspace with 16bit stack,
- * try to fix the higher word of ESP, as the CPU
- * won't restore it.
- * This is an "official" bug of all the x86-compatible
- * CPUs, which we can try to work around to make
- * dosemu and wine happy. */
- movl PT_OLDESP(%esp), %eax
- movl %esp, %edx
- call patch_espfix_desc
+/*
+ * Setup and switch to ESPFIX stack
+ *
+ * We're returning to userspace with a 16 bit stack. The CPU will not
+ * restore the high word of ESP for us on executing iret... This is an
+ * "official" bug of all the x86-compatible CPUs, which we can work
+ * around to make dosemu and wine happy. We do this by preloading the
+ * high word of ESP with the high word of the userspace ESP while
+ * compensating for the offset by changing to the ESPFIX segment with
+ * a base address that matches for the difference.
+ */
+ 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 */
pushl $__ESPFIX_SS
CFI_ADJUST_CFA_OFFSET 4
- pushl %eax
+ push %eax /* new kernel esp */
CFI_ADJUST_CFA_OFFSET 4
+ /* Disable interrupts, but do not irqtrace this section: we
+ * will soon execute iret and the tracer was already set to
+ * the irqstate after the iret */
DISABLE_INTERRUPTS(CLBR_EAX)
- TRACE_IRQS_OFF
- lss (%esp), %esp
+ lss (%esp), %esp /* switch to espfix segment */
CFI_ADJUST_CFA_OFFSET -8
jmp restore_nocheck
CFI_ENDPROC
@@ -716,15 +727,24 @@ PTREGSCALL(vm86)
PTREGSCALL(vm86old)
.macro FIXUP_ESPFIX_STACK
- /* since we are on a wrong stack, we cant make it a C code :( */
+/*
+ * Switch back for ESPFIX stack to the normal zerobased stack
+ *
+ * We can't call C functions using the ESPFIX stack. This code reads
+ * the high word of the segment base from the GDT and swiches to the
+ * normal stack and adjusts ESP with the matching offset.
+ */
+ /* fixup the stack */
PER_CPU(gdt_page, %ebx)
- GET_DESC_BASE(GDT_ENTRY_ESPFIX_SS, %ebx, %eax, %ax, %al, %ah)
- addl %esp, %eax
+ mov GDT_ENTRY_ESPFIX_SS * 8 + 4(%ebx), %al /* bits 16..23 */
+ mov GDT_ENTRY_ESPFIX_SS * 8 + 7(%ebx), %ah /* bits 24..31 */
+ shl $16, %eax
+ addl %esp, %eax /* the adjusted stack pointer */
pushl $__KERNEL_DS
CFI_ADJUST_CFA_OFFSET 4
pushl %eax
CFI_ADJUST_CFA_OFFSET 4
- lss (%esp), %esp
+ lss (%esp), %esp /* switch to the normal stack segment */
CFI_ADJUST_CFA_OFFSET -8
.endm
.macro UNWIND_ESPFIX_STACK
@@ -1329,7 +1349,7 @@ nmi_stack_correct:
xorl %edx,%edx # zero error code
movl %esp,%eax # pt_regs pointer
call do_nmi
- jmp restore_nocheck_notrace
+ jmp restore_all_notrace
CFI_ENDPROC
nmi_stack_fixup:
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index dc5ed4b..8663afb 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -13,7 +13,6 @@
#include <asm/segment.h>
#include <asm/page_types.h>
#include <asm/pgtable_types.h>
-#include <asm/desc.h>
#include <asm/cache.h>
#include <asm/thread_info.h>
#include <asm/asm-offsets.h>
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 54b29bb..fa54f78 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -12,7 +12,6 @@
#include <linux/linkage.h>
#include <linux/threads.h>
#include <linux/init.h>
-#include <asm/desc.h>
#include <asm/segment.h>
#include <asm/pgtable.h>
#include <asm/page.h>
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