diff options
Diffstat (limited to 'i386/i386/user_ldt.c')
| -rw-r--r-- | i386/i386/user_ldt.c | 72 |
1 files changed, 55 insertions, 17 deletions
diff --git a/i386/i386/user_ldt.c b/i386/i386/user_ldt.c index 9db6da5d..a59b1769 100644 --- a/i386/i386/user_ldt.c +++ b/i386/i386/user_ldt.c @@ -170,23 +170,6 @@ i386_set_ldt(thread, first_selector, desc_list, count, desc_list_inline) case ACC_P | ACC_PL_U | ACC_CODE_CR: case ACC_P | ACC_PL_U | ACC_CALL_GATE_16: case ACC_P | ACC_PL_U | ACC_CALL_GATE: - /* Silently cap the segment's limit at VM_MAX_ADDRESS. */ - { - unsigned base = ((dp->base_high << 24) - | (dp->base_med << 16) | dp->base_low); - unsigned limit - = ((dp->limit_high << 16) | dp->limit_low); - if (dp->granularity & SZ_G) - limit <<= 12; - if (base > VM_MAX_ADDRESS) - { - fill_descriptor_base(dp, 0); - fill_descriptor_limit(dp, 0); - } - else if (base + limit > VM_MAX_ADDRESS - || base + limit < base) - fill_descriptor_limit(dp, VM_MAX_ADDRESS - base); - } break; default: return KERN_INVALID_ARGUMENT; @@ -416,3 +399,58 @@ user_ldt_free(user_ldt) user_ldt->desc.limit_low + 1 + sizeof(struct x86_desc)); } + + +kern_return_t +i386_set_gdt (thread_t thread, int *selector, struct x86_desc *desc) +{ + int idx; + + if (thread == THREAD_NULL) + return KERN_INVALID_ARGUMENT; + + if (*selector == -1) + { + for (idx = sel_idx (USER_GDT); idx < sel_idx (USER_GDT) + USER_GDT_SLOTS; + ++idx) + if ((thread->pcb->ims.user_gdt[idx].access & ACC_P) == 0) + { + *selector = (idx << 3) | SEL_PL_U; + break; + } + if (idx == sel_idx (USER_GDT) + USER_GDT_SLOTS) + return KERN_NO_SPACE; /* ? */ + } + else if ((*selector & (SEL_LDT|SEL_PL)) != SEL_PL_U + || sel_idx (*selector) < USER_GDT + || sel_idx (*selector) >= USER_GDT + USER_GDT_SLOTS) + return KERN_INVALID_ARGUMENT; + else + idx = sel_idx (*selector); + + if ((desc->access & ACC_P) == 0) + memset (&thread->pcb->ims.user_gdt[idx], 0, + sizeof thread->pcb->ims.user_gdt[idx]); + else if ((desc->access & (ACC_TYPE|ACC_PL)) != (ACC_TYPE_USER|ACC_PL_U)) + return KERN_INVALID_ARGUMENT; + else + thread->pcb->ims.user_gdt[idx] = *desc; + + return KERN_SUCCESS; +} + +kern_return_t +i386_get_gdt (thread_t thread, int selector, struct x86_desc *desc) +{ + if (thread == THREAD_NULL) + return KERN_INVALID_ARGUMENT; + + if ((selector & (SEL_LDT|SEL_PL)) != SEL_PL_U + || sel_idx (selector) < USER_GDT + || sel_idx (selector) >= USER_GDT + USER_GDT_SLOTS) + return KERN_INVALID_ARGUMENT; + + *desc = thread->pcb->ims.user_gdt[sel_idx (selector)]; + + return KERN_SUCCESS; +} |