kernel: Patches to run processes in Ring 3.

kernel/src/main.c

@@ -63,6 +63,8 @@ static void hcf(void) {
     }
 }
 
+
+
 int init() {
     asm("int $0x80");
     while (1)
@@ -71,6 +73,8 @@ int init() {
 
 struct limine_framebuffer *fb;
 
+char kstack[8192];
+
 // The following will be our kernel's entry point.
 // If renaming kmain() to something else, make sure to change the
 // linker script accordingly.
@@ -99,7 +103,7 @@ void kmain(void) {
     printf("\n  Soaplin 1.0-sild is booting up your computer...\n\n");
     //printf("Physical kernel EP: %p", entrypoint_request.entry);
     
-    gdt_init();
+    gdt_init(&kstack[8192]);
     idt_init();
 
     sse_init();
@@ -108,15 +112,17 @@ void kmain(void) {
     vmm_init();
 
     pit_init(1000);
-    sched_init();
+    //sched_init();
+    //user_init();
 
-    uint64_t *mem = pmm_request_page();
+    uint8_t *mem = pmm_request_page();
     mem[0] = 0xCD;
     mem[1] = 0x80;
-    mem[2] = 0xFE;
-    mem[3] = 0xEB;
-    sched_process *proc = sched_create("Init", 0x1000, SCHED_USER_PROCESS);
-    vmm_map(proc->pm, 0x1000, (uint64_t)mem, VMM_PRESENT | VMM_USER);
+    mem[2] = 0xF4;
+    //mem[3] = 0xFE;
+    pagemap_t* pm = vmm_alloc_pm();
+    vmm_map(pm, 0x1000, (uint64_t)mem, VMM_PRESENT | VMM_USER);
+    sched_process *proc = sched_create("Init", 0x1000, pm, SCHED_USER_PROCESS);
 
     log("kernel - Soaplin initialized sucessfully.\n");
     while (1)

kernel/src/mm/vmm.c

@@ -3,6 +3,7 @@
 #include "mm/pmm.h"
 #include "mm/memop.h"
 #include "sys/log.h"
+#include "vmm.h"
 #include <stddef.h>
 
 
@@ -148,12 +149,26 @@ void vmm_load_pagemap(pagemap_t *pm) {
 }
 
 static uint64_t *__vmm_get_next_lvl(uint64_t *level, uint64_t entry, uint64_t flags) {
-    if (level[entry] & 1)
-      return HIGHER_HALF(PTE_GET_ADDR(level[entry]));
-    uint64_t *pml = HIGHER_HALF(pmm_request_page());
-    memset(pml, 0, PMM_PAGE_SIZE);
-    level[entry] = (uint64_t)PHYSICAL(pml) | (flags & 0xFFF); // N'ajoute que les flags pertinents
-    return pml;
+    if (!(level[entry] & 1)){
+        uint64_t *pml = HIGHER_HALF(pmm_request_page());
+        memset(pml, 0, PMM_PAGE_SIZE);
+        level[entry] = (uint64_t)PHYSICAL(pml);
+    }
+    level[entry] |= (flags & 0xFFF); // N'ajoute que les flags pertinents
+    return HIGHER_HALF(PTE_GET_ADDR(level[entry]));
+}
+
+uint64_t vmm_get_flags(pagemap_t* pm, uint64_t vaddr) {
+    uint64_t pml4_entry = (vaddr >> 39) & 0x1ff;
+    uint64_t pml3_entry = (vaddr >> 30) & 0x1ff;
+    uint64_t pml2_entry = (vaddr >> 21) & 0x1ff;
+    uint64_t pml1_entry = (vaddr >> 12) & 0x1ff;
+
+    uint64_t *pml3 = __vmm_get_next_lvl(pm->toplevel, pml4_entry, 0);
+    uint64_t *pml2 = __vmm_get_next_lvl(pml3, pml3_entry, 0);
+    uint64_t *pml1 = __vmm_get_next_lvl(pml2, pml2_entry, 0);
+
+    return pml1[pml1_entry] & 0x7000000000000FFF;
 }
   
 void vmm_map(pagemap_t *pm, uint64_t vaddr, uint64_t paddr, uint64_t flags) {

kernel/src/mm/vmm.h

@@ -37,5 +37,6 @@ pagemap_t *vmm_alloc_pm();
 void vmm_init();
 void vmm_release_pm(pagemap_t *pm);
 void vmm_load_pagemap(pagemap_t *pm);
+uint64_t vmm_get_flags(pagemap_t* pm, uint64_t vaddr);
 void vmm_map(pagemap_t *pm, uint64_t vaddr, uint64_t paddr, uint64_t flags);
 void vmm_unmap(pagemap_t *pm, uint64_t vaddr) ;

kernel/src/sched/sched.c

@@ -29,7 +29,7 @@ void sched_init() {
         "mode.\n");
 }
 
-sched_process *sched_create(char *name, uint64_t entry_point, uint32_t flags)
+sched_process *sched_create(char *name, uint64_t entry_point, pagemap_t* pm, uint32_t flags)
 {
     // TODO: implement a separate strlen function
     // as there's like 4 strlen impls in the kernel.
@@ -43,12 +43,13 @@ sched_process *sched_create(char *name, uint64_t entry_point, uint32_t flags)
     memcpy(proc->name, name, i);
     proc->pid = current_pid;
     proc->type = SCHED_RUNNING;
+    proc->flags = flags;
 
     // We are about to setup the registers ourself.
     // If it's broken, it's a boom in the ass of your computer
     // (and a CPU exception)
 
-    proc->pm = vmm_alloc_pm();
+    proc->pm = pm;
 
     uint64_t *stack_phys = pmm_request_page();
     uint64_t *stack_virt = (uint64_t*)0x40000000;
@@ -107,5 +108,5 @@ void schedule(registers_t *regs)
     memcpy(regs, &curr_proc->regs, sizeof(registers_t));
 
     // Finally, load our pagemap
-    //vmm_load_pagemap(curr_proc->pm);
+    vmm_load_pagemap(curr_proc->pm);
 }

kernel/src/sched/sched.h

@@ -16,6 +16,7 @@ typedef struct _sched_process {
     char name[128];
     int pid;
     int type;
+    int flags;
 
     registers_t regs;
     pagemap_t *pm;
@@ -34,6 +35,6 @@ extern sched_process *proc_list;
 //extern sched_process *idle_process;
 
 void sched_init();
-sched_process *sched_create(char *name, uint64_t entry_point, uint32_t flags);
+sched_process *sched_create(char *name, uint64_t entry_point, pagemap_t *pm, uint32_t flags);
 void sched_exit(sched_process *proc);
 void schedule(registers_t *regs);

kernel/src/sys/arch/x86_64/gdt.c

@@ -2,6 +2,7 @@
 #include <stdint.h>
 #include <sys/arch/x86_64/gdt.h>
 #include <sys/log.h>
+#include <mm/memop.h>
 
 gdt_table def_table = {
   {
@@ -25,10 +26,10 @@ gdt_table def_table = {
 
 tssr tss_list[256]; // One tssr per CPU
 
-void gdt_init() {
+void gdt_init( char* kstack ) {
 
   // TODO: adapt for multiprocessor kernel
-  tss_list[0].iopb = sizeof(tssr);
+  tss_list[0].rsp[0] = (uint64_t)kstack;
   uintptr_t tss = (uintptr_t)&tss_list[0];
 
   def_table.tss_entry.length = sizeof(tss_entry);

kernel/src/sys/arch/x86_64/gdt.h

@@ -26,7 +26,7 @@ typedef struct {
 
 typedef struct {
   uint32_t resv;
-  uint64_t rsp[3];
+  uint64_t rsp[4];
   uint64_t resv1;
   uint64_t ist[7];
   uint64_t resv2;
@@ -34,4 +34,4 @@ typedef struct {
   uint16_t iopb;
 } __attribute__((packed)) tssr; // Per CPU
 
-void gdt_init();
+void gdt_init(char* kstack);

kernel/src/sys/arch/x86_64/idt.c

@@ -29,10 +29,16 @@ void idt_init() {
     idtr.limit = (uint16_t)sizeof(idt_entry_t) * 256 - 1;
 
     for (uint16_t vector = 0; vector <= 256; vector++) {
+        if (vector == 0x80)
+            continue; // We skip the syscall handler, since it should be called from user space.
         idt_set_descriptor(vector, isr_stub_table[vector], 0x8E);
         vectors[vector] = 1;
     }
 
+    uint16_t vector = 0x80;
+    idt_set_descriptor(vector, isr_stub_table[vector], 0xEE);
+    vectors[vector] = 1;
+
     pic_init();
     pic_unmask_irq(1);
     

kernel/src/sys/arch/x86_64/interrupts.c

@@ -39,6 +39,14 @@ void exception_handler(registers_t *regs) {
     if (regs->int_no < 32) {
         //panic(kmode_cpu_exception, regs);
         log("ints - %d (RIP: %p, ERR: %d)\n", regs->int_no, regs->rip, regs->err_code);
+
+        if(regs->int_no == 0xe) {
+            uint64_t cr2;
+            asm ("mov %%cr2, %0" : "=r"(cr2));
+            log("ints - PF: Faulting location: %p\n", cr2);
+            log("ints - PF: Faulting page flags: %p\n", vmm_get_flags(vmm_current_pm, cr2));
+        }
+
         dump_backtrace(regs);
         asm ("cli");
         while (1)
@@ -63,7 +71,9 @@ void exception_handler(registers_t *regs) {
     }
     else if (regs->int_no == 0x80)
     {
-        log("syscall - Hello World! Current process: %s", curr_proc->name);
+        log("syscall - Hello World! Current process: %s\n", curr_proc->name);
+        if (curr_proc->flags == SCHED_USER_PROCESS)
+        log("syscall - Btw we made it to userspace, baby!\n", curr_proc->name);
     }
     //logln(info, "arch/ints", "Received interrupt %d\n", regs->int_no);
     pic_ack(regs->int_no - 32);

kernel/zgpAU9u.patch

@@ -0,0 +1,208 @@
+diff --git a/kernel/src/main.c b/kernel/src/main.c
+index b5b6fa0..2d326ef 100755
+--- a/kernel/src/main.c
++++ b/kernel/src/main.c
+@@ -63,6 +63,8 @@ static void hcf(void) {
+     }
+ }
+ 
++
++
+ int init() {
+     asm("int $0x80");
+     while (1)
+@@ -71,6 +73,8 @@ int init() {
+ 
+ struct limine_framebuffer *fb;
+ 
++char kstack[8192];
++
+ // The following will be our kernel's entry point.
+ // If renaming kmain() to something else, make sure to change the
+ // linker script accordingly.
+@@ -99,7 +103,7 @@ void kmain(void) {
+     printf("\n  Soaplin 1.0-sild is booting up your computer...\n\n");
+     //printf("Physical kernel EP: %p", entrypoint_request.entry);
+     
+-    gdt_init();
++    gdt_init(&kstack[8192]);
+     idt_init();
+ 
+     sse_init();
+@@ -115,8 +119,9 @@ void kmain(void) {
+     mem[1] = 0x80;
+     mem[2] = 0xFE;
+     mem[3] = 0xEB;
+-    sched_process *proc = sched_create("Init", 0x1000, SCHED_USER_PROCESS);
+-    vmm_map(proc->pm, 0x1000, (uint64_t)mem, VMM_PRESENT | VMM_USER);
++    pagemap_t* pm = vmm_alloc_pm();
++    vmm_map(pm, 0x1000, (uint64_t)mem, VMM_PRESENT | VMM_USER);
++    sched_process *proc = sched_create("Init", 0x1000, pm, SCHED_USER_PROCESS);
+ 
+     log("kernel - Soaplin initialized sucessfully.\n");
+     while (1)
+diff --git a/kernel/src/mm/vmm.c b/kernel/src/mm/vmm.c
+index 6d905e2..f7df03e 100755
+--- a/kernel/src/mm/vmm.c
++++ b/kernel/src/mm/vmm.c
+@@ -3,6 +3,7 @@
+ #include "mm/pmm.h"
+ #include "mm/memop.h"
+ #include "sys/log.h"
++#include "vmm.h"
+ #include <stddef.h>
+ 
+ 
+@@ -148,12 +149,26 @@ void vmm_load_pagemap(pagemap_t *pm) {
+ }
+ 
+ static uint64_t *__vmm_get_next_lvl(uint64_t *level, uint64_t entry, uint64_t flags) {
+-    if (level[entry] & 1)
+-      return HIGHER_HALF(PTE_GET_ADDR(level[entry]));
+-    uint64_t *pml = HIGHER_HALF(pmm_request_page());
+-    memset(pml, 0, PMM_PAGE_SIZE);
+-    level[entry] = (uint64_t)PHYSICAL(pml) | (flags & 0xFFF); // N'ajoute que les flags pertinents
+-    return pml;
++    if (!(level[entry] & 1)){
++        uint64_t *pml = HIGHER_HALF(pmm_request_page());
++        memset(pml, 0, PMM_PAGE_SIZE);
++        level[entry] = (uint64_t)PHYSICAL(pml);
++    }
++    level[entry] |= (flags & 0xFFF); // N'ajoute que les flags pertinents
++    return HIGHER_HALF(PTE_GET_ADDR(level[entry]));
++}
++
++uint64_t vmm_get_flags(pagemap_t* pm, uint64_t vaddr) {
++    uint64_t pml4_entry = (vaddr >> 39) & 0x1ff;
++    uint64_t pml3_entry = (vaddr >> 30) & 0x1ff;
++    uint64_t pml2_entry = (vaddr >> 21) & 0x1ff;
++    uint64_t pml1_entry = (vaddr >> 12) & 0x1ff;
++
++    uint64_t *pml3 = __vmm_get_next_lvl(pm->toplevel, pml4_entry, 0);
++    uint64_t *pml2 = __vmm_get_next_lvl(pml3, pml3_entry, 0);
++    uint64_t *pml1 = __vmm_get_next_lvl(pml2, pml2_entry, 0);
++
++    return pml1[pml1_entry] & 0x7000000000000FFF;
+ }
+   
+ void vmm_map(pagemap_t *pm, uint64_t vaddr, uint64_t paddr, uint64_t flags) {
+diff --git a/kernel/src/mm/vmm.h b/kernel/src/mm/vmm.h
+index 97239b4..4e4c8aa 100755
+--- a/kernel/src/mm/vmm.h
++++ b/kernel/src/mm/vmm.h
+@@ -37,5 +37,6 @@ pagemap_t *vmm_alloc_pm();
+ void vmm_init();
+ void vmm_release_pm(pagemap_t *pm);
+ void vmm_load_pagemap(pagemap_t *pm);
++uint64_t vmm_get_flags(pagemap_t* pm, uint64_t vaddr);
+ void vmm_map(pagemap_t *pm, uint64_t vaddr, uint64_t paddr, uint64_t flags);
+ void vmm_unmap(pagemap_t *pm, uint64_t vaddr) ;
+\ No newline at end of file
+diff --git a/kernel/src/sched/sched.c b/kernel/src/sched/sched.c
+index b39c2fc..f09da0d 100755
+--- a/kernel/src/sched/sched.c
++++ b/kernel/src/sched/sched.c
+@@ -29,7 +29,7 @@ void sched_init() {
+         "mode.\n");
+ }
+ 
+-sched_process *sched_create(char *name, uint64_t entry_point, uint32_t flags)
++sched_process *sched_create(char *name, uint64_t entry_point, pagemap_t* pm, uint32_t flags)
+ {
+     // TODO: implement a separate strlen function
+     // as there's like 4 strlen impls in the kernel.
+@@ -48,7 +48,7 @@ sched_process *sched_create(char *name, uint64_t entry_point, uint32_t flags)
+     // If it's broken, it's a boom in the ass of your computer
+     // (and a CPU exception)
+ 
+-    proc->pm = vmm_alloc_pm();
++    proc->pm = pm;
+ 
+     uint64_t *stack_phys = pmm_request_page();
+     uint64_t *stack_virt = (uint64_t*)0x40000000;
+@@ -107,5 +107,5 @@ void schedule(registers_t *regs)
+     memcpy(regs, &curr_proc->regs, sizeof(registers_t));
+ 
+     // Finally, load our pagemap
+-    //vmm_load_pagemap(curr_proc->pm);
++    vmm_load_pagemap(curr_proc->pm);
+ }
+\ No newline at end of file
+diff --git a/kernel/src/sched/sched.h b/kernel/src/sched/sched.h
+index f5d2b04..5dcf23d 100755
+--- a/kernel/src/sched/sched.h
++++ b/kernel/src/sched/sched.h
+@@ -34,6 +34,6 @@ extern sched_process *proc_list;
+ //extern sched_process *idle_process;
+ 
+ void sched_init();
+-sched_process *sched_create(char *name, uint64_t entry_point, uint32_t flags);
++sched_process *sched_create(char *name, uint64_t entry_point, pagemap_t *pm, uint32_t flags);
+ void sched_exit(sched_process *proc);
+ void schedule(registers_t *regs);
+\ No newline at end of file
+diff --git a/kernel/src/sys/arch/x86_64/gdt.c b/kernel/src/sys/arch/x86_64/gdt.c
+index 0559625..d6d712a 100755
+--- a/kernel/src/sys/arch/x86_64/gdt.c
++++ b/kernel/src/sys/arch/x86_64/gdt.c
+@@ -2,6 +2,7 @@
+ #include <stdint.h>
+ #include <sys/arch/x86_64/gdt.h>
+ #include <sys/log.h>
++#include <mm/memop.h>
+ 
+ gdt_table def_table = {
+   {
+@@ -25,10 +26,10 @@ gdt_table def_table = {
+ 
+ tssr tss_list[256]; // One tssr per CPU
+ 
+-void gdt_init() {
++void gdt_init( char* kstack ) {
+ 
+   // TODO: adapt for multiprocessor kernel
+-  tss_list[0].iopb = sizeof(tssr);
++  tss_list[0].rsp[0] = (uint64_t)kstack;
+   uintptr_t tss = (uintptr_t)&tss_list[0];
+ 
+   def_table.tss_entry.length = sizeof(tss_entry);
+diff --git a/kernel/src/sys/arch/x86_64/gdt.h b/kernel/src/sys/arch/x86_64/gdt.h
+index 8e51e53..6004d06 100755
+--- a/kernel/src/sys/arch/x86_64/gdt.h
++++ b/kernel/src/sys/arch/x86_64/gdt.h
+@@ -26,7 +26,7 @@ typedef struct {
+ 
+ typedef struct {
+   uint32_t resv;
+-  uint64_t rsp[3];
++  uint64_t rsp[4];
+   uint64_t resv1;
+   uint64_t ist[7];
+   uint64_t resv2;
+@@ -34,4 +34,4 @@ typedef struct {
+   uint16_t iopb;
+ } __attribute__((packed)) tssr; // Per CPU
+ 
+-void gdt_init();
+\ No newline at end of file
++void gdt_init(char* kstack);
+\ No newline at end of file
+diff --git a/kernel/src/sys/arch/x86_64/interrupts.c b/kernel/src/sys/arch/x86_64/interrupts.c
+index d243629..6bab678 100755
+--- a/kernel/src/sys/arch/x86_64/interrupts.c
++++ b/kernel/src/sys/arch/x86_64/interrupts.c
+@@ -39,6 +39,14 @@ void exception_handler(registers_t *regs) {
+     if (regs->int_no < 32) {
+         //panic(kmode_cpu_exception, regs);
+         log("ints - %d (RIP: %p, ERR: %d)\n", regs->int_no, regs->rip, regs->err_code);
++
++        if(regs->int_no == 0xe) {
++            uint64_t cr2;
++            asm ("mov %%cr2, %0" : "=r"(cr2));
++            log("faulting locations: %p\n", cr2);
++            log("faulting page flags: %p\n", vmm_get_flags(vmm_current_pm, cr2));
++        }
++
+         dump_backtrace(regs);
+         asm ("cli");
+         while (1)