diff options
Diffstat (limited to 'drivers/lguest/segments.c')
| -rw-r--r-- | drivers/lguest/segments.c | 28 |
1 files changed, 17 insertions, 11 deletions
diff --git a/drivers/lguest/segments.c b/drivers/lguest/segments.c index ede46581351..c4fb424dfdd 100644 --- a/drivers/lguest/segments.c +++ b/drivers/lguest/segments.c @@ -81,8 +81,8 @@ static void fixup_gdt_table(struct lg_cpu *cpu, unsigned start, unsigned end) * sometimes careless and leaves this as 0, even though it's * running at privilege level 1. If so, we fix it here. */ - if ((cpu->arch.gdt[i].b & 0x00006000) == 0) - cpu->arch.gdt[i].b |= (GUEST_PL << 13); + if (cpu->arch.gdt[i].dpl == 0) + cpu->arch.gdt[i].dpl |= GUEST_PL; /* * Each descriptor has an "accessed" bit. If we don't set it @@ -90,7 +90,7 @@ static void fixup_gdt_table(struct lg_cpu *cpu, unsigned start, unsigned end) * that entry into a segment register. But the GDT isn't * writable by the Guest, so bad things can happen. */ - cpu->arch.gdt[i].b |= 0x00000100; + cpu->arch.gdt[i].type |= 0x1; } } @@ -114,13 +114,19 @@ void setup_default_gdt_entries(struct lguest_ro_state *state) /* * The TSS segment refers to the TSS entry for this particular CPU. - * Forgive the magic flags: the 0x8900 means the entry is Present, it's - * privilege level 0 Available 386 TSS system segment, and the 0x67 - * means Saturn is eclipsed by Mercury in the twelfth house. */ - gdt[GDT_ENTRY_TSS].a = 0x00000067 | (tss << 16); - gdt[GDT_ENTRY_TSS].b = 0x00008900 | (tss & 0xFF000000) - | ((tss >> 16) & 0x000000FF); + gdt[GDT_ENTRY_TSS].a = 0; + gdt[GDT_ENTRY_TSS].b = 0; + + gdt[GDT_ENTRY_TSS].limit0 = 0x67; + gdt[GDT_ENTRY_TSS].base0 = tss & 0xFFFF; + gdt[GDT_ENTRY_TSS].base1 = (tss >> 16) & 0xFF; + gdt[GDT_ENTRY_TSS].base2 = tss >> 24; + gdt[GDT_ENTRY_TSS].type = 0x9; /* 32-bit TSS (available) */ + gdt[GDT_ENTRY_TSS].p = 0x1; /* Entry is present */ + gdt[GDT_ENTRY_TSS].dpl = 0x0; /* Privilege level 0 */ + gdt[GDT_ENTRY_TSS].s = 0x0; /* system segment */ + } /* @@ -135,8 +141,8 @@ void setup_guest_gdt(struct lg_cpu *cpu) */ cpu->arch.gdt[GDT_ENTRY_KERNEL_CS] = FULL_EXEC_SEGMENT; cpu->arch.gdt[GDT_ENTRY_KERNEL_DS] = FULL_SEGMENT; - cpu->arch.gdt[GDT_ENTRY_KERNEL_CS].b |= (GUEST_PL << 13); - cpu->arch.gdt[GDT_ENTRY_KERNEL_DS].b |= (GUEST_PL << 13); + cpu->arch.gdt[GDT_ENTRY_KERNEL_CS].dpl |= GUEST_PL; + cpu->arch.gdt[GDT_ENTRY_KERNEL_DS].dpl |= GUEST_PL; } /*H:650 |