fix usermode interrupts. add ability to define custom interrupt handlersmain

12 files changed, 93 insertions, 39 deletions

diff --git a/arch/x86_64/device/processor.c b/arch/x86_64/device/processor.c
index ff920c8..1b3daa2 100644
--- a/arch/x86_64/device/processor.c
+++ b/arch/x86_64/device/processor.c
@@ -44,7 +44,7 @@ typedef union msr_star
         uint32_t eip;
         uint16_t kcs;
         uint16_t ucs;
-    };
+    }__attribute__((packed));
     uint32_t v[2];
 } msr_star_t;
 
@@ -65,7 +65,7 @@ s_enable_sce(void)
 
     msr_star_t star;
     star.kcs = GDT_OFFSET_KERNEL_CODE;
-    star.ucs = GDT_OFFSET_USER_CODE;
+    star.ucs = GDT_OFFSET_USER_NULL;
     wrmsr(MSR_STAR, star.v[0], star.v[1]);
 
     extern void _syscall_entry(void);
diff --git a/arch/x86_64/gdt.c b/arch/x86_64/gdt.c
index 3756d21..9c172d2 100644
--- a/arch/x86_64/gdt.c
+++ b/arch/x86_64/gdt.c
@@ -57,9 +57,7 @@ static segment_descriptor_t s_gdt[] = {
         .limit_0_15 = 0,
         .base_0_15 = 0,
         .base_16_23 = 0,
-        .type_flags = GDT_SEGMENT_TYPE_TSS_AVAIL |
-                      GDT_SEGMENT_FLAG_DPL(0) |
-                      GDT_SEGMENT_FLAG_P,
+        .type_flags = 0x89,
         .limit_16_19_avlx = 0,
         .base_24_31 = 0
     },
@@ -71,29 +69,25 @@ void
 gdt_setup(processor_t *processor)
 {
     size_t gdtw = GDT_ENTRY_COUNT * sizeof(segment_descriptor_t);
-    klogf("%X\n", gdtw);
     memcpy(processor->gdt, &s_gdt, gdtw);
 
-    processor->gdtr.base = (uintptr_t)&s_gdt;
+    processor->gdtr.base = (uintptr_t)&processor->gdt;
     processor->gdtr.length = gdtw - 1;
 
     segment_descriptor_t *tss_lo = &processor->gdt[GDT_ENTRY_TSS_LOW];
     segment_descriptor_t *tss_hi = &processor->gdt[GDT_ENTRY_TSS_HIGH];
 
     uintptr_t tssb = (uintptr_t)&processor->tss;
-    size_t tssl = sizeof(tss_t);
+    size_t tssl = sizeof(tss_t) - 1;
 
     tss_lo->limit_0_15 = tssl & 0xFF;
     tss_lo->base_0_15 = tssb & 0xFFFF;
     tss_lo->base_16_23 = (tssb >> 16) & 0xFF;
     tss_lo->base_24_31 = (tssb >> 24) & 0xFF;
-    tss_hi->limit_0_15 = (tssb >> 32) & 0xFFFF;
-    tss_hi->base_0_15 = (tssb >> 48) & 0xFFFF;
-
-    tss_lo->limit_16_19_avlx = (tssl >> 16) & 0xF;
+    *(uint32_t*)tss_hi = (tssb >> 32) & 0xFFFFFFFF;
 
     processor->tss.iopb = tssl;
-    
+
     extern void gdt_load(void*);
     gdt_load(&processor->gdtr);
 
diff --git a/arch/x86_64/idt.c b/arch/x86_64/idt.c
index 1080f92..2eebf41 100644
--- a/arch/x86_64/idt.c
+++ b/arch/x86_64/idt.c
@@ -1,12 +1,20 @@
 #include "arch/x86_64/tables.h"
 #include "arch/x86_64/idt.h"
+#include "print.h"
 
 __attribute__((aligned(0x10)))
-interrupt_gate_t s_idtd[256];
+static interrupt_gate_t s_idtd[256];
+
+kernel_isr_handler_t kernel_isr_handles[256];
 
 void
 isr_handle(ivt_state_t* state)
 {
+    kernel_isr_handler_t kernel_handle = kernel_isr_handles[state->num];
+    if(kernel_handle) {
+        kernel_handle(state);
+        return;
+    }
     kpanic_state(state, "Unhandled interrupt %i", state->num);
 }
 
@@ -34,6 +42,8 @@ idt_setup(processor_t *processor)
     processor->idtr.base = (uintptr_t)&s_idtd;
     processor->idtr.length = sizeof(s_idtd) - 1;
     
-    extern void idt_load(void* idtr);
-    idt_load(&processor->idtr);
+    klogf("%X\n", s_idtd[0].type_flags);
+
+    __asm__ volatile("lidt %0":: "m"(processor->idtr));
+    __asm__ volatile("cli");
 }
diff --git a/arch/x86_64/init.c b/arch/x86_64/init.c
index 7a2f67d..9e32898 100644
--- a/arch/x86_64/init.c
+++ b/arch/x86_64/init.c
@@ -1,6 +1,7 @@
 #include "init.h"
 #include "bootargs.h"
 #include "device/initrd.h"
+#include "api/init.h"
 #include "arch/x86_64/page.h"
 #include "arch/x86_64/processor.h"
 #include "device/processor.h"
@@ -180,5 +181,6 @@ init_load(void)
     extern tcb_t *_init_tcb;
     _init_tcb->sp = (uintptr_t)usermode_sp;
 
+    extern void usermode(void*, void*);
     usermode((void*)init_ehdr->e_entry, usermode_sp);
 }
diff --git a/arch/x86_64/ivt.s b/arch/x86_64/ivt.s
index a64f6b7..a1592be 100644
--- a/arch/x86_64/ivt.s
+++ b/arch/x86_64/ivt.s
@@ -1,14 +1,13 @@
 .section .text
-.global idt_load
-.type idt_load @function
-idt_load:
-    lidt (%rdi)
-    sti
-    retq
-.size idt_load, . - idt_load
-
 .include "arch/x86_64/savestate.s"
 
+.macro swapgs_if_necessary
+    cmp $0x08, 0x8(%rsp)
+    je 1f
+    swapgs
+1:
+.endm
+
 .extern isr_handle
 .type __isr_head @function
 __isr_head:
@@ -20,14 +19,13 @@ __isr_head:
     popall
 
     addq $16, %rsp
+    swapgs_if_necessary
     iretq
 
-.extern __isr_err
-.extern __isr_num
-
 .macro defn_isr_err num:req
 .type __isr\num @function
 __isr\num:
+    swapgs_if_necessary
     pushq $\num
     jmp __isr_head
 .size __isr\num, . - __isr\num
@@ -36,6 +34,7 @@ __isr\num:
 .macro defn_isr num:req
 .type __isr\num @function
 __isr\num:
+    swapgs_if_necessary
     pushq $0
     pushq $\num
     jmp __isr_head
diff --git a/arch/x86_64/lgdt.s b/arch/x86_64/lgdt.s
index 55e37b5..ccafe42 100644
--- a/arch/x86_64/lgdt.s
+++ b/arch/x86_64/lgdt.s
@@ -4,9 +4,9 @@ gdt_load:
     lgdt (%rdi)
 .reload_segments:
     pushq $0x8
-    leaq .reload_cs, %rax
+    leaq .reload_cs(%rip), %rax
     pushq %rax
-    lretq
+    retfq
 .reload_cs:
     movw $0x10, %ax
     movw %ax, %ds
diff --git a/arch/x86_64/memory/pml4.c b/arch/x86_64/memory/pml4.c
index d5fb56b..b42ce06 100644
--- a/arch/x86_64/memory/pml4.c
+++ b/arch/x86_64/memory/pml4.c
@@ -1,5 +1,6 @@
 #include "arch/x86_64/page.h"
 #include "arch/x86_64/processor.h"
+#include "arch/x86_64/idt.h"
 #include "device/processor.h"
 #include "memory.h"
 #include "boot.h"
@@ -7,6 +8,7 @@
 #include "init.h"
 #include "string.h"
 #include "jove.h"
+#include "print.h"
 #include "api/error.h"
 #include <stdint.h>
 
@@ -81,6 +83,27 @@ pml4_try_map(pmle_t *pml4, uintptr_t pptr, uintptr_t vptr)
     return KE_OK;
 }
 
+static void
+s_handle_pagefault(ivt_state_t *state)
+{
+    int eflags = state->err;
+    bool e_present = eflags & 1;
+    bool e_write = (eflags & 2) > 0;
+    bool e_user = (eflags & 4) > 0;
+    bool e_insf = (eflags & 16) > 0;
+
+    uintptr_t faultaddr;
+    __asm__ volatile("movq %%cr2, %0": "=r"(faultaddr));
+
+    kprintf("\n%s %s %s page for %s\n",
+            e_user ? "User" : "Kernel",
+            e_write ? "wrote to" : "read from",
+            e_present ? "present" : "non-present",
+            e_insf ? "instruction" : "memory");
+    kprintf("Faulting address: %p\n", faultaddr);
+    kpanic_state(state, "Unhandled page fault");
+}
+
 __attribute__((aligned(0x1000))) pmle_t s_kernel_pml4[512]; // Page L4
 __attribute__((aligned(0x1000))) pmle_t s_kernel_pml3[512]; // Page L3
 __attribute__((aligned(0x1000))) pmle_t s_kernel_pml2[512]; // Page directory
@@ -139,6 +162,7 @@ pml4_setup_init(void)
     }
 
     __asm__ volatile("mov %0, %%cr3":: "r"(kernel_pml4_base));
+    kernel_isr_handles[EXCEPTION_PF] = s_handle_pagefault;
 
     //Add page mapping object to init directory.
     _initDirectory.entries[INIT_OBJECT_PAGEMAP] = (objdir_entry_t) {
diff --git a/arch/x86_64/panic.c b/arch/x86_64/panic.c
index 2e34500..522550f 100644
--- a/arch/x86_64/panic.c
+++ b/arch/x86_64/panic.c
@@ -25,12 +25,13 @@ kpanic_state(ivt_state_t *state, const char *fmt, ...)
     kprintf("R12 %p | R13 %p | R14 %p | R15 %p\n", state->r12, state->r13, state->r14, state->r15);
     kprintf("RIP %p\n", state->rip);
 
+    /*
     kprintf("\nStack trace:\n");
     struct stackFrame *frame = (struct stackFrame*)state->rbp;
     for(size_t framei = 0; frame && framei < 64; ++framei) {
         kprintf("%i %p : %p\n", framei, frame, frame->eip);
         frame = frame->ebp;
-    }
+    }*/
 
     hcf();
 }
diff --git a/arch/x86_64/syscall/invoke-mapping.c b/arch/x86_64/syscall/invoke-mapping.c
index 186b420..e470034 100644
--- a/arch/x86_64/syscall/invoke-mapping.c
+++ b/arch/x86_64/syscall/invoke-mapping.c
@@ -1,5 +1,5 @@
 #include "arch/x86_64/syscall/wrappers.h"
-#include "arch/x86_64/syscall.h"
+#include "arch/x86_64/api/syscall.h"
 #include "arch/x86_64/page.h"
 #include <stddef.h>
 #include "api/error.h"
@@ -20,7 +20,9 @@ s_handle_invoke_mapping_exists(
     pmle_t *target_pml;
     uint8_t target_depth;
     SYSCALL_PAYLOAD_TAKEPML(payload, payload_at, pml4, target_depth, target_pml);
-    if(target_pml == NULL || !target_pml->p) return KE_DNE;
+    if(target_pml == NULL || !target_pml->p) {
+        return KE_DNE;
+    }
 
 #ifdef DBG_SYSCALL
     klogf("pml d%i %p from %p exists\n", target_depth, target_pml, pml4);
@@ -46,7 +48,9 @@ s_handle_invoke_mapping_map(
     objdir_entry_t *untyped_entry;
     SYSCALL_PAYLOAD_TAKEOBJ(payload, payload_at, untyped_pathw, untyped_entry);
     
-    if(untyped_entry->type != KO_MEMORY_UNTYPED) return KE_BADOBJ;
+    if(untyped_entry->type != KO_MEMORY_UNTYPED) {
+        return KE_BADOBJ;
+    }
     mtx_acquire(&untyped_entry->lock);
 
     if((untyped_entry->data & 0xFFF) != 0) {
@@ -69,6 +73,7 @@ s_handle_invoke_mapping_map(
         memset(untyped, 0, 0x1000);
     }
     untyped_entry->type = KO_NONE;
+    untyped_entry->data = 0;
 #ifdef DBG_SYSCALL
     klogf("map %p[%i] to %p[%i]\n", untyped_phys, target_depth, target_pml, ((uintptr_t)target_pml & 0xFFF) / 8);
 #endif
diff --git a/arch/x86_64/syscall/syscall.c b/arch/x86_64/syscall/syscall.c
index 7ddd179..1ed991d 100644
--- a/arch/x86_64/syscall/syscall.c
+++ b/arch/x86_64/syscall/syscall.c
@@ -35,18 +35,36 @@ __attribute__((naked))
 void _syscall_entry(void)
 {
     __asm__ volatile(" \
-            pushq %%r11; \
-            pushq %%rcx; \
             swapgs; \
             movq %%gs:%c[tcb], %%rax; \
             movq %%rsp, %c[sp](%%rax); \
             movq %c[ksp](%%rax), %%rsp; \
             pushq %c[sp](%%rax); \
+            pushq %%r11; \
+            pushq %%rcx; \
+            pushq %%rbx; \
+            pushq %%rbp; \
+            pushq %%r12; \
+            pushq %%r13; \
+            pushq %%r14; \
+            pushq %%r15; \
             callq _syscall_handler; \
             swapgs; \
-            popq %%rsp; \
+            popq %%r15; \
+            popq %%r14; \
+            popq %%r13; \
+            popq %%r12; \
+            popq %%rbp; \
+            popq %%rbx; \
+            xorq %%rdx, %%rdx; \
+            xorq %%rsi, %%rsi; \
+            xorq %%rdi, %%rdi; \
+            xorq %%r8, %%r8; \
+            xorq %%r9, %%r9; \
+            xorq %%r10, %%r10; \
             popq %%rcx; \
             popq %%r11; \
+            popq %%rsp; \
             sysretq;"
             ::
             [tcb] "i"(offsetof(processor_t, tcb)),
diff --git a/arch/x86_64/tasking/tcb.c b/arch/x86_64/tasking/tcb.c
index 9877455..3cae29f 100644
--- a/arch/x86_64/tasking/tcb.c
+++ b/arch/x86_64/tasking/tcb.c
@@ -24,8 +24,10 @@ tcb_init(void *task_main)
         .type = KO_TCB,
         .data = vptr_tophys_koff((uintptr_t)_init_tcb)
     };
-    
-    ((processor_t*)processor_current())->tcb = _init_tcb;
+
+    processor_t* proc = processor_current();
+    proc->tcb = _init_tcb;
+    proc->tss.rsp0 = _init_tcb->ksp;
     
     __asm__ volatile("\
             movq %0, %%rsp; \
diff --git a/arch/x86_64/usermode.c b/arch/x86_64/usermode.c
index 24a31a1..0285e7d 100644
--- a/arch/x86_64/usermode.c
+++ b/arch/x86_64/usermode.c
@@ -6,7 +6,6 @@ void usermode(void *ip, void *sp)
     __asm__ volatile("mov %0, %%rsp; \
                       movq %1, %%rcx; \
                       movq $0x202, %%r11; \
-                      cli; \
                       swapgs; \
                       sysretq"::
                       "r"(sp), "r"(ip): "memory");