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Merge pull request 'mmap' (#8) from mmap into master 

Reviewed-on: #8
This commit is contained in:
mathieu 2024-02-11 15:29:57 +01:00
parent bd25bb8478 c3f3eb435e
commit 607fcc7121
25 changed files with 801 additions and 110 deletions
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2
.gitignore vendored
View File

@ -1,6 +1,6 @@
serialOut
disk.img
kernel
kernel.sym
kernel.debug
userspace/user
docs/*.html

44
arch/x86/exception.c
View File

@ -45,9 +45,9 @@ int exceptionSetRoutine(int exception, exception_handler handler)
void print_handler(struct cpu_state *frame, ulong intr)
{
int intNbInt = intr;
VGAPrintf(RED, BLACK, 0, VGA_HEIGHT - 1, "EXCEPTION %d", intNbInt);
VGAPrintf(RED, BLACK, 0, VGA_HEIGHT - 1, "EXCEPTION %lu", intr);
printf("Exception %lu at 0x%p\n", intr, (void *)cpu_context_get_PC(frame));
asm("hlt");
}
@ -55,20 +55,43 @@ void pagefault_handler(struct cpu_state *frame, ulong intr)
{
struct thread *current = getCurrentThread();
struct uAddrSpace *as = processGetAddrSpace(current->process);
vaddr_t faultAddr = cpu_context_get_EX_faulting_vaddr(frame);
assert(frame == current->cpuState);
if (cpu_context_is_in_user_mode(current->cpuState)) {
if(!uAddrSpaceCheckNAlloc(as, faultAddr))
return;
struct uAddrSpace *as = processGetAddrSpace(current->process);
vaddr_t faultAddr = cpu_context_get_EX_faulting_vaddr(frame);
int needMMUSetup =
(uAddrSpaceGetMMUContext(as) != getCurrentThread()->squattedContext);
printf("page fault while in thread [%s] at 0x%p when trying to access 0x%p err_code 0x%x\n", current->name,
(void *)cpu_context_get_PC(frame), (void *)faultAddr, cpu_context_get_EX_err(frame));
if (cpu_context_is_in_user_mode(frame)) {
if (needMMUSetup) {
threadChangeCurrentContext(uAddrSpaceGetMMUContext(as));
}
if (!uAddrSpaceHeapCheckNAlloc(as, faultAddr))
goto release_context;
// PAGE_FAULT is a interrupt with an error code (see exception_wrapper.S)
uint32_t error_code = cpu_context_get_EX_err(frame);
int ret = uAddrSpaceSolvePageFault(as, faultAddr, error_code & 0x2);
if (!ret)
goto release_context;
printf(
"page fault while in thread [%s] at 0x%p when trying to access 0x%p err_code 0x%x ressource ret %d\n",
current->name, (void *)cpu_context_get_PC(frame), (void *)faultAddr, error_code,
ret);
printf("Killing User Thread\n");
threadExit();
release_context:
if (needMMUSetup)
threadChangeCurrentContext(NULL);
return;
}
VGAPrintf(RED, BLACK, 0, VGA_HEIGHT - 1, "PAGE FAULT %d", intr);
(void)intr;
for (;;)
continue;
}
@ -79,5 +102,6 @@ int exceptionSetup()
exceptionSetRoutine(i, print_handler);
}
exceptionSetRoutine(EXCEPTION_PAGE_FAULT, pagefault_handler);
return 0;
}

2
arch/x86/exception_wrappers.S
View File

@ -165,7 +165,7 @@
iret
.endm
/*List of exception w or w/o err codehttps://wiki.osdev.org/Exceptions*/
/* List of exception w or w/o err code https://wiki.osdev.org/Exceptions */
.irp exception_id, 8, 10, 11, 12, 13, 14, 17, 30
exception_mac_with_errcode exception_id
.endr

1
arch/x86/paging.h
View File

@ -17,6 +17,7 @@
#define PAGING_MEM_USER (1U << 0)
#define PAGING_MEM_READ (1U << 1)
#define PAGING_MEM_WRITE (1U << 2)
#define PAGING_MEM_EXEC (1U << 3)
int pagingSetup(paddr_t lowerKernelAddr, paddr_t upperKernelAddr);

6
core/alloc.h
View File

@ -3,11 +3,17 @@
#include "stddef.h"
#include "types.h"
/** Arbitrary size allocator **/
/*
* Initialize malloc system
*/
int allocSetup(size_t sizeOfArea, vaddr_t *areaAddr, vaddr_t *descAddr, vaddr_t *entryAddr);
/*
* Add Slice for some simple/commun size
*/
int allocPopulate();
/*
* Allow malloc to allocate elements of this precise size.

8
core/allocArea.c
View File

@ -7,6 +7,14 @@
#include "mem.h"
#include "stdarg.h"
struct memArea {
vaddr_t startAddr;
uint nbPages;
struct memArea *next;
struct memArea *prev;
};
static struct memArea *freeArea;
static struct memArea *usedArea;

34
core/allocArea.h
View File

@ -9,19 +9,29 @@
#define AREA_PHY_MAP (1<<0)
#define AREA_MEM_TOP PAGING_MIRROR_VADDR
struct memArea {
vaddr_t startAddr;
uint nbPages;
struct memArea *next;
struct memArea *prev;
};
/**
* Initialize the Area subsystem
**/
void areaInit(vaddr_t firstMemUsed, vaddr_t lastUsed, vaddr_t stack_bottom, vaddr_t stack_top);
/**
* Request a virtual memory area of @param nbPages
**/
vaddr_t areaAlloc(unsigned int nbPages, uint32_t flags);
// Remove an area from the free ones but do not add it into used ones.
// This area should be latter added woth areaAdd.
// Used by malloc to avoid recursivity issue
vaddr_t areaBook(unsigned int nbPages, uint32_t flags);
/**
* Free a virtual area
**/
int areaFree(vaddr_t addr);
/**
* Remove an area from the "free" ones but do not add it into used ones.
* This area should be latter added with areaAdd.
* Used by malloc to avoid recursivity issue
**/
vaddr_t areaBook(unsigned int nbPages, uint32_t flags);
/**
* Declare a virtual region to be managed by the subsytem
*/
int areaAdd(vaddr_t begin, vaddr_t end, int isFree);

11
core/elf.c
View File

@ -5,6 +5,7 @@
#include "paging.h"
#include "thread.h"
#include "types.h"
#include "zero.h"
/**
* Make sure the program is in a valid ELF format, map it into memory,
@ -13,12 +14,11 @@
* @return 0 when the program is not a valid ELF
*/
uaddr_t loadElfProg(const char *prog, struct process * proc)
uaddr_t loadElfProg(const char *prog, struct process *proc)
{
int i;
uaddr_t lastUserAddr = 0;
struct uAddrSpace *as = processGetAddrSpace(proc);
/* e_ident value */
#define ELFMAG0 0x7f
@ -138,6 +138,11 @@ uaddr_t loadElfProg(const char *prog, struct process * proc)
unrefPhyPage(ppage);
}
// Hack: Even if already allocated mark the adresse space as managed by a ressource
// So this address space is not used by another ressource.
uaddr = elf_phdrs[i].p_vaddr;
zeroMmap(as, &uaddr, elf_phdrs[i].p_memsz, PAGING_MEM_USER | PAGING_MEM_WRITE | PAGING_MEM_READ, 0);
/* Copy segment into memory */
memcpy((void *)elf_phdrs[i].p_vaddr, (void *)(prog + elf_phdrs[i].p_offset),
elf_phdrs[i].p_filesz);

38
core/main.c
View File

@ -28,6 +28,7 @@
#include "time.h"
#include "types.h"
#include "vga.h"
#include "zero.h"
#define CHECK_FLAG(flags, bit) ((flags) & (1 << (bit)))
@ -83,27 +84,28 @@ void loadUserSpace()
return;
}
struct process *proc = processCreate("UserSpace");
{
struct process *proc = processCreate("init");
struct uAddrSpace *as = processGetAddrSpace(proc);
threadChangeCurrentContext(processGetMMUContext(proc));
uaddr_t prog = loadElfProg(buf + FILE_HEADER_SIZE, proc);
if (prog == (uaddr_t)NULL) {
free(buf);
return;
threadChangeCurrentContext(processGetMMUContext(proc));
uaddr_t prog = loadElfProg(buf + FILE_HEADER_SIZE, proc);
if (prog == (uaddr_t)NULL) {
free(buf);
return;
}
// Alloc user stack
size_t stackSize = PAGE_SIZE * 2;
uaddr_t stack = PAGING_TOP_USER_ADDRESS - stackSize + 1;
zeroMmap(as, &stack, stackSize, PAGING_MEM_USER | PAGING_MEM_WRITE | PAGING_MEM_READ,
0);
threadCreateUser("init", proc, prog, 0, 0, stack + stackSize - 4);
processUnref(proc);
threadChangeCurrentContext(NULL);
}
// Alloc user stack
uaddr_t stackTop = 0xfffffffc;
uaddr_t stackBottom = ALIGN_DOWN(stackTop, PAGE_SIZE);
paddr_t stackPhy = allocPhyPage(1);
assert(pageMap(stackBottom, stackPhy,
PAGING_MEM_USER | PAGING_MEM_WRITE | PAGING_MEM_READ) == 0);
unrefPhyPage(stackPhy);
threadCreateUser("UserProg", proc, prog, 0, 0, stackTop);
processUnref(proc);
threadChangeCurrentContext(NULL);
free(buf);
}

26
core/mem.h
View File

@ -2,7 +2,8 @@
#include "stdint.h"
#include "types.h"
/** Physical Page related function
/**
* Physical Page management
*/
#define PAGE_SHIFT 12U
@ -20,10 +21,33 @@ struct phyMemDesc {
struct phyMemDesc *next, *prev;
};
/**
* Initi Physical Page management subsystem
**/
int memSetup(paddr_t upperMem, paddr_t * firstUsed, paddr_t *lastUsed);
/**
* Declare a physical region to be managed by the physica page subsystem
**/
int memAddBank(paddr_t bottomMem, paddr_t topMem, int isFree);
/**
* Request @params nbPage free physical pages
**/
paddr_t allocPhyPage(uint nbPage);
/**
* Decrement the nb of user of a given physical page
**/
int unrefPhyPage(paddr_t addr);
/**
* Increment the nb of user of a given physical page
**/
int refPhyPage(paddr_t addr);
/**
* Return the number of physical allocated pages
**/
unsigned long getNbAllocatedPage(void);
void memGetStat(uint *free, uint *used);

55
core/syscall.c
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@ -5,7 +5,10 @@
#include "stdarg.h"
#include "thread.h"
#include "types.h"
#include "uaccess.h"
#include "uaddrspace.h"
#include "zero.h"
int syscallExecute(int syscallId, const struct cpu_state *userCtx)
{
@ -55,6 +58,58 @@ int syscallExecute(int syscallId, const struct cpu_state *userCtx)
threadChangeCurrentContext(NULL);
break;
}
case SYSCALL_ID_MMAP: {
struct uAddrSpace *as;
uaddr_t uaddr;
uaddr_t uaddr_ptr;
size_t size;
uint32_t rights;
uint32_t flags;
uaddr_t userPath;
char path[256];
as = processGetAddrSpace(getCurrentThread()->process);
ret = syscallGet5args(userCtx, (unsigned int *)&uaddr_ptr, (unsigned int *)&size,
(unsigned int *)&rights, (unsigned int *)&flags,
(unsigned int *)&userPath);
if (ret)
break;
if (memcpyFromUser((vaddr_t)&uaddr, uaddr_ptr, sizeof(uaddr)) != sizeof(uaddr)) {
ret = -EFAULT;
break;
}
strzcpyFromUser((vaddr_t *)path, (uaddr_t *)userPath, sizeof(path));
printf("Trying mmap for device %s at %lu\n", path, (vaddr_t)uaddr);
if (strcmp(path, "/dev/zero") == 0) {
ret = zeroMmap(as, &uaddr, size, rights, flags);
}
if (!ret) {
if (memcpyToUser(uaddr_ptr, (vaddr_t)&uaddr, sizeof(uaddr)) != sizeof(uaddr)) {
ret = -EFAULT;
break;
}
}
break;
}
case SYSCALL_ID_MUNMAP: {
struct uAddrSpace *as;
uaddr_t uaddr;
size_t size;
ret = syscallGet2args(userCtx, (unsigned int *)&uaddr, (unsigned int *)&size);
if (ret)
break;
as = processGetAddrSpace(getCurrentThread()->process);
ret = uAddrSpaceUnmap(as, uaddr, size);
break;
}
default:
printf("Unknon syscall id %d\n", syscallId);
ret = -ENOENT;

6
core/syscall.h
View File

@ -1,6 +1,6 @@
#pragma once
#ifdef __KERNEL__
#include "cpu_context.h"
#include "cpu_context.h"
#endif
#define SYSCALL_ID_EXIT 1
@ -8,7 +8,9 @@
#define SYSCALL_ID_PUTC 3
#define SYSCALL_ID_READ 4
#define SYSCALL_ID_TEST 5
#define SYSCALL_ID_BRK 6
#define SYSCALL_ID_BRK 6
#define SYSCALL_ID_MMAP 7
#define SYSCALL_ID_MUNMAP 8
#ifdef __KERNEL__
int syscallExecute(int syscallId, const struct cpu_state *user_ctx);

49
core/uaccess.c
View File

@ -1,10 +1,12 @@
#include "uaccess.h"
#include "assert.h"
#include "errno.h"
#include "minmax.h"
#include "mmuContext.h"
#include "paging.h"
#include "process.h"
#include "thread.h"
#include "uaccess.h"
#include "types.h"
static int bindtoUserContext()
{
@ -42,6 +44,17 @@ static int memcpyUserMemNoCheck(vaddr_t dest, vaddr_t src, size_t size)
return size;
}
int memcpyToUser(uaddr_t to, vaddr_t from, size_t size)
{
if ((uint)to < PAGING_BASE_USER_ADDRESS)
return -EPERM;
if ((uint)to > PAGING_TOP_USER_ADDRESS - size)
return -EPERM;
return memcpyUserMemNoCheck(to, from, size);
}
int memcpyFromUser(vaddr_t to, uaddr_t from, size_t size)
{
@ -52,3 +65,37 @@ int memcpyFromUser(vaddr_t to, uaddr_t from, size_t size)
return memcpyUserMemNoCheck(to, from, size);
}
static int strzcpyFromUserNoCheck(char *to, char *from, size_t size)
{
int ret;
ret = bindtoUserContext();
if (ret != 0)
return ret;
for (unsigned int i = 0; i < size; i++) {
to[i] = from[i];
if (from[i] == '\0')
break;
}
if (size > 0)
to[size - 1] = '\0';
ret = unbindUserContext();
if (ret != 0)
return ret;
return size;
}
int strzcpyFromUser(vaddr_t *to, uaddr_t *from, size_t size)
{
if ((uint)from < PAGING_BASE_USER_ADDRESS)
return -EPERM;
if ((uint)from > PAGING_TOP_USER_ADDRESS - size)
return -EPERM;
return strzcpyFromUserNoCheck((char *)to, (char *)from, size);
}

3
core/uaccess.h
View File

@ -1,5 +1,8 @@
#pragma once
#include "types.h"
#include "stddef.h"
#include "stdarg.h"
int memcpyFromUser(vaddr_t to, uaddr_t from, size_t size);
int memcpyToUser(uaddr_t to, vaddr_t from, size_t size);
int strzcpyFromUser(vaddr_t *to, uaddr_t *from, size_t size);

328
core/uaddrspace.c
View File

@ -1,5 +1,6 @@
#include "uaddrspace.h"
#include "alloc.h"
#include "errno.h"
#include "kernel.h"
#include "klibc.h"
#include "list.h"
@ -14,18 +15,6 @@
#include <stddef.h>
#include <stdint.h>
struct uAddrVirtualReg {
uaddr_t addr;
size_t size;
int right; // PAGING_MEM_*
uint32_t offset; // in the mappedRessource
uint flags;
struct mappedRessource *res;
struct uAddrVirtualReg *nextInAddrSpace, *prevInAddrSpace;
struct uAddrVirtualReg *nextInMappedRes, *prevInMappedRes;
};
struct uAddrSpace {
struct process *process; // The process that is represented by this AS
struct mmu_context *ctx; // The corresponding MMU configuration
@ -33,22 +22,85 @@ struct uAddrSpace {
struct uAddrVirtualReg *listVirtualReg; // List of Virtual Region used by this process
uaddr_t heapStart; // Start of the Head
size_t heapSize; // Hep size -> modified by brk()
size_t heapSize; // Heap size -> modified by brk()
};
struct mappedRessourceOps {
int (*open)(struct uAddrVirtualReg *vreg);
int (*close)(struct uAddrVirtualReg *vreg);
int (*unmap)(struct uAddrVirtualReg *vregi, uaddr_t addr, size_t size);
int (*nopage)(struct uAddrVirtualReg *vregi, uaddr_t addr,
int right); // Called by the pageflt handler when the page is missing
};
static int hasOverlap(uaddr_t addr1, size_t size1, uaddr_t addr2, size_t size2)
{
return max(addr1, addr2) < min(addr1 + size1, addr2 + size2);
}
struct mappedRessource {
int right; // PAGING_MEM_*
struct mappedRessourceOps *ops;
struct uAddrVirtualReg *listVirtualReg;
};
static struct uAddrVirtualReg *findVirtualRegionFromAddr(struct uAddrSpace *as, uaddr_t uaddr, size_t size)
{
struct uAddrVirtualReg *reg;
int idx;
list_foreach_named(as->listVirtualReg, reg, idx, prevInAddrSpace, nextInAddrSpace)
{
if (hasOverlap(reg->addr, reg->size, uaddr, size))
return reg;
}
return NULL;
}
static struct uAddrVirtualReg *findVirtualRegionBeforeAddr(struct uAddrSpace *as,
uaddr_t uaddr)
{
struct uAddrVirtualReg *reg, *prev = NULL;
int idx;
list_foreach_named(as->listVirtualReg, reg, idx, prevInAddrSpace, nextInAddrSpace)
{
if (uaddr < reg->addr)
break;
prev = reg;
}
return prev;
}
/**
* Find a address not alreay used in the virtual region of the AS.
* This address will be equals to uaddr if possible and could take size
*/
static uaddr_t findFreeAddrInVirtualRegion(struct uAddrSpace *as, uaddr_t uaddr, size_t size)
{
struct uAddrVirtualReg *reg, *regNext, *regOver;
if (uaddr < PAGING_BASE_USER_ADDRESS)
uaddr = PAGING_BASE_USER_ADDRESS;
if(uaddr > PAGING_TOP_USER_ADDRESS - size)
uaddr = PAGING_TOP_USER_ADDRESS - size;
reg = findVirtualRegionFromAddr(as, uaddr, size);
if (!reg)
return uaddr;
int idx;
regOver = reg;
//Find last region that overlap
list_foreach_named(reg->nextInAddrSpace, regNext, idx, prevInAddrSpace, nextInAddrSpace){
if(!hasOverlap(uaddr, size, regNext->addr, regNext->size))
break;
regOver = regNext;
}
uaddr = regOver->addr + regOver->size;
list_foreach_named(regOver->nextInAddrSpace, regNext, idx, prevInAddrSpace,
nextInAddrSpace)
{
if (!hasOverlap(uaddr, size, regNext->addr, regNext->size) &&
uaddr <= (PAGING_TOP_USER_ADDRESS - size)) {
return uaddr;
}
if (reg == regNext) // Already checked region
break;
uaddr = regNext->addr + regNext->size;
}
return (uaddr_t)NULL;
}
struct uAddrSpace *uAddrSpaceCreate(struct process *proc)
{
@ -76,16 +128,119 @@ int uAddrSpaceDelete(struct uAddrSpace *addr)
struct uAddrVirtualReg *reg;
list_collapse_named(addr->listVirtualReg, reg, nextInAddrSpace, prevInAddrSpace) {
// TODO Implement me with real ressources
assertmsg(reg->res == NULL, "Unsupported mapper ressource");
// This is memory allocated for the heap just unmap it to free it
pr_devel("Freeing heap 0x%lx for process %s\n", reg->addr, processGetName(addr->process));
pageUnmap(reg->addr);
free(reg);
if (reg->res == NULL) {
// This is memory allocated for the heap just unmap it to free it
pr_devel("Freeing heap 0x%lx for process %s\n", reg->addr,
processGetName(addr->process));
pageUnmap(reg->addr);
free(reg);
} else {
if(reg->res->ops){
if(reg->res->ops->unmap)
reg->res->ops->unmap(reg, reg->addr, reg->size);
if(reg->res->ops->close)
reg->res->ops->close(reg);
}
free(reg);
}
}
return mmuContextUnref(addr->ctx);
}
/**
* Find the associated uAddrVirtualReg associated to the unmap space and free them;
*/
int uAddrSpaceUnmap(struct uAddrSpace *as, uaddr_t uaddr, size_t size)
{
if (uaddr < PAGING_BASE_USER_ADDRESS || uaddr > PAGING_TOP_USER_ADDRESS - size)
return -EINVAL;
if (!IS_ALIGNED(uaddr, PAGE_SIZE) || size <= 0)
return -EINVAL;
if(!as)
return -EINVAL;
size = ALIGN(size, PAGE_SIZE);
struct uAddrVirtualReg *reg = as->listVirtualReg;
struct uAddrVirtualReg *lastReg = reg ? reg->prevInAddrSpace : NULL;
while (reg != NULL) {
if (reg->addr > uaddr + size)
break;
struct uAddrVirtualReg *next = reg->nextInAddrSpace;
// The Virtual Region is completly inside the unmaped space
if (reg->addr >= uaddr && (reg->addr + reg->size <= uaddr + size)) {
list_delete_named(as->listVirtualReg, reg, prevInAddrSpace, nextInAddrSpace);
list_delete_named(reg->res->listVirtualReg, reg, prevInMappedRes, nextInMappedRes);
if (reg->res->ops && reg->res->ops->unmap)
reg->res->ops->unmap(reg, uaddr, size);
if (reg->res->ops && reg->res->ops->close)
reg->res->ops->close(reg);
if (reg == next)//singleton
next = NULL;
free(reg);
// Unmaped space is inside and smaller than the VR
// VR should be splitted
} else if (reg->addr > uaddr && (reg->addr + reg->size < uaddr + size)) {
struct uAddrVirtualReg *new =
(struct uAddrVirtualReg *)zalloc(sizeof(struct uAddrSpace));
if (!new)
return -ENOMEM;
new->addr = uaddr + size;
new->size = reg->addr + reg->size - (uaddr + size);
new->right = reg->right;
new->offset = uaddr + size - reg->addr;
reg->size = uaddr - reg->addr;
list_insert_after_named(as->listVirtualReg, reg, new, prevInAddrSpace,
nextInAddrSpace);
list_insert_after_named(reg->res->listVirtualReg, reg, new, prevInMappedRes,
nextInMappedRes);
if (reg->res->ops && reg->res->ops->unmap)
reg->res->ops->unmap(reg, uaddr, size);
if (new->res->ops && new->res->ops->open)
new->res->ops->open(new);
break;
// Only affect the beginning
} else if (uaddr <= reg->addr && uaddr + size > reg->addr) {
size_t offset = uaddr + size - reg->addr;
reg->size -= offset;
reg->offset += offset;
reg->addr += offset;
if (reg->res->ops && reg->res->ops->unmap)
reg->res->ops->unmap(reg, uaddr, size);
break;
// Only affect the end
} else if (uaddr > reg->addr && uaddr + size > reg->addr + reg->size) {
size_t unmapSize = reg->addr + reg->size - uaddr;
reg->size = uaddr - reg->addr;
if (reg->res->ops && reg->res->ops->unmap)
reg->res->ops->unmap(reg, uaddr, unmapSize);
}
reg = next;
if (reg == lastReg)
break;
}
int needMMUSetup = as->ctx != getCurrentThread()->squattedContext;
if (needMMUSetup)
threadChangeCurrentContext(as->ctx);
for (vaddr_t addr = uaddr; addr < uaddr + size; addr += PAGE_SIZE) {
pageUnmap(addr);
}
if (needMMUSetup)
threadChangeCurrentContext(NULL);
return 0;
}
struct mmu_context *uAddrSpaceGetMMUContext(struct uAddrSpace *addr)
{
return addr->ctx;
@ -114,7 +269,7 @@ uaddr_t sysBrk(struct uAddrSpace *as, uaddr_t newHeapTop)
incSize = ALIGN(newHeapTop - (as->heapStart + as->heapSize), PAGE_SIZE);
if (incSize < 0){
//TODO how to free allocated page by uAddrSpaceCheckNAlloc
//TODO how to free allocated page by uAddrSpaceHeapCheckNAlloc
return as->heapStart + as->heapSize;
}
@ -123,12 +278,14 @@ uaddr_t sysBrk(struct uAddrSpace *as, uaddr_t newHeapTop)
return as->heapStart + as->heapSize;
}
int uAddrSpaceCheckNAlloc(struct uAddrSpace *as, vaddr_t addr)
int uAddrSpaceHeapCheckNAlloc(struct uAddrSpace *as, vaddr_t addr)
{
struct uAddrVirtualReg *newReg;
int right = PAGING_MEM_USER | PAGING_MEM_WRITE | PAGING_MEM_READ;
pr_devel("Checking 0x%lx inside 0x%lx and 0x%lx\n", addr, as->heapStart, as->heapStart +as->heapSize);
pr_devel("Heap check: 0x%lx inside 0x%lx and 0x%lx\n", addr, as->heapStart,
as->heapStart + as->heapSize);
if (addr < as->heapStart || addr >= as->heapStart + as->heapSize) {
return -1;
}
@ -159,3 +316,106 @@ free_ppage:
unrefPhyPage(ppage);
return -1;
}
int uAddrSpaceMmap(struct uAddrSpace *as, uaddr_t *uaddr, size_t size, uint32_t rights,
uint32_t flags, struct mappedRessource *res, uint32_t offset )
{
int ret = 0;
uaddr_t hint_uaddr = *uaddr;
if (res == NULL || res->ops == NULL || res->ops->nopage == NULL)
return -ENOENT;
if (!IS_ALIGNED(hint_uaddr, PAGE_SIZE) || size <= 0)
return -EINVAL;
if (flags & UA_MAP_SHARED) {
if (((rights & PAGING_MEM_READ) && !(res->allowedRight & PAGING_MEM_READ)) ||
((rights & PAGING_MEM_WRITE) && !(res->allowedRight & PAGING_MEM_WRITE)) ||
((rights & PAGING_MEM_EXEC) && !(res->allowedRight & PAGING_MEM_EXEC)))
return -EPERM;
}
size = ALIGN(size, PAGE_SIZE);
struct uAddrVirtualReg *reg =
(struct uAddrVirtualReg *)malloc(sizeof(struct uAddrVirtualReg));
if (!reg)
return -ENOMEM;
if (flags & UA_MAP_FIXED) {
if (hint_uaddr < PAGING_BASE_USER_ADDRESS ||
hint_uaddr > PAGING_TOP_USER_ADDRESS - size) {
ret = -EINVAL;
goto free_reg;
}
ret = uAddrSpaceUnmap(as, hint_uaddr, size);
if (ret)
goto free_reg;
} else {
hint_uaddr = findFreeAddrInVirtualRegion(as, hint_uaddr, size);
if (!hint_uaddr) {
ret = -ENOMEM;
goto free_reg;
}
}
reg->addr = hint_uaddr;
reg->size = size;
reg->right = rights;
reg->res = res;
reg->offset = offset;
// TODO merge it with prev/next one
// keep the AddrSpace list sorted
struct uAddrVirtualReg *prev = findVirtualRegionBeforeAddr(as, hint_uaddr);
if (prev)
list_insert_after_named(as->listVirtualReg, prev, reg, prevInAddrSpace,
nextInAddrSpace);
else
list_add_tail_named(as->listVirtualReg, reg, prevInAddrSpace, nextInAddrSpace);
list_add_tail_named(reg->res->listVirtualReg, reg, prevInMappedRes, nextInMappedRes);
if (res->onResMapped) {
int cbret = res->onResMapped(reg);
if (cbret) {
pr_devel("Call back failed on ressource mmaped\n");
ret = uAddrSpaceUnmap(as, reg->addr, reg->size);
}
}
if (res->ops->open)
res->ops->open(reg);
*uaddr = hint_uaddr;
return ret;
free_reg:
free(reg);
return ret;
}
/**
* Check if @param faultAddr could be managed by the uAddrVirtualReg from @param as
**/
int uAddrSpaceSolvePageFault(struct uAddrSpace *as, vaddr_t faultAddr, int isWriteAccess)
{
struct uAddrVirtualReg *reg;
int rights = PAGING_MEM_READ | PAGING_MEM_USER;
reg = findVirtualRegionFromAddr(as, faultAddr, 1);
if (reg == NULL)
return -EFAULT;
pr_devel("Virtual Region for pageflt found\n");
if (isWriteAccess && !(reg->right & PAGING_MEM_WRITE))
return -EACCES;
if (isWriteAccess || (reg->right & PAGING_MEM_WRITE))
rights |= PAGING_MEM_WRITE;
if (reg->res->ops->nopage(reg, faultAddr, rights))
return -EFAULT;
return 0;
}

44
core/uaddrspace.h
View File

@ -7,9 +7,47 @@
struct uAddrSpace;
struct uAddrVirtualReg;
struct uAddrSpace * uAddrSpaceCreate(struct process *proc);
#define UA_MAP_SHARED (1 << 0)
#define UA_MAP_PRIVATE (1 << 1)
#define UA_MAP_FIXED (1 << 2)
// TODO : move this struct to .c and add accessors
struct uAddrVirtualReg {
uaddr_t addr;
size_t size;
int right; // PAGING_MEM_*
uint32_t offset; // in the mappedRessource
uint flags;
struct mappedRessource *res;
struct uAddrVirtualReg *nextInAddrSpace, *prevInAddrSpace;
struct uAddrVirtualReg *nextInMappedRes, *prevInMappedRes;
};
struct mappedRessourceOps {
int (*open)(struct uAddrVirtualReg *vreg);
int (*close)(struct uAddrVirtualReg *vreg);
int (*unmap)(struct uAddrVirtualReg *vreg, uaddr_t addr, size_t size);
int (*nopage)(struct uAddrVirtualReg *vreg, uaddr_t addr,
int right); // Called by the pageflt handler when the page is missing
};
struct mappedRessource {
int allowedRight; // PAGING_MEM_*
struct mappedRessourceOps *ops;
struct uAddrVirtualReg *listVirtualReg;
void *customData;
int (*onResMapped)(struct uAddrVirtualReg *reg); // Callabck for when the ressourced get mapped
};
struct uAddrSpace *uAddrSpaceCreate(struct process *proc);
int uAddrSpaceDelete(struct uAddrSpace *addr);
struct mmu_context * uAddrSpaceGetMMUContext(struct uAddrSpace *addr);
struct mmu_context *uAddrSpaceGetMMUContext(struct uAddrSpace *addr);
int uAddrSpaceSetHeap(struct uAddrSpace *as, uaddr_t addr, size_t size);
int uAddrSpaceCheckNAlloc(struct uAddrSpace *as, vaddr_t addr);
int uAddrSpaceHeapCheckNAlloc(struct uAddrSpace *as, vaddr_t addr);
uaddr_t sysBrk(struct uAddrSpace *as, uaddr_t newHeapTop);
int uAddrSpaceMmap(struct uAddrSpace *as, uaddr_t *uaddr, size_t size, uint32_t rights,
uint32_t flags, struct mappedRessource *res, uint32_t offset);
int uAddrSpaceUnmap(struct uAddrSpace *as, uaddr_t uaddr, size_t size);
int uAddrSpaceSolvePageFault(struct uAddrSpace *as, vaddr_t faultAddr, int isWriteAccess);

27
custom_gdb_extension.py
View File

@ -184,18 +184,19 @@ class ListDumpCmd(gdb.Command):
"list_dump", gdb.COMMAND_USER
)
def _print_list(self, val):
def _print_list(self, val, next_name):
"""Walk through the linked list.
We will simply follow the 'next' pointers until we encounter the HEAD again
"""
idx = 0
head = val
thread_ptr = val
result = ""
while thread_ptr != 0 and (idx == 0 or thread_ptr != head):
result += gdb.execute('p *({}){}'.format(str(thread_ptr.type),thread_ptr), to_string=True)
thread_ptr = thread_ptr["next"]
result += gdb.execute('p *({}){}'.format(str(thread_ptr.type),
thread_ptr), to_string=True)
thread_ptr = thread_ptr[next_name]
idx += 1
result = ("Found a Linked List with %d items:" % idx) + "\n" + result
return result
@ -209,17 +210,21 @@ class ListDumpCmd(gdb.Command):
# We can pass args here and use Python CLI utilities like argparse
# to do argument parsing
print("Args Passed: %s" % args)
if args:
ptr_val = gdb.parse_and_eval(args)
else:
ptr_val = gdb.parse_and_eval("currentThread")
thread_name = "currentThread"
next_name = "next"
if(args):
args_arr = args.split()
thread_name = args_arr[0]
if(len(args_arr) >= 2):
next_name = args_arr[1]
ptr_val = gdb.parse_and_eval(thread_name)
try:
ptr_val["next"]
ptr_val[next_name]
except:
print("Expected pointer argument with a next field")
print("Expected pointer argument with a %s field" % next_name)
return
print(self._print_list(ptr_val))
print(self._print_list(ptr_val, next_name))
register_pretty_printer(None, CustomPrettyPrinterLocator(), replace=True)

1
disk.sfdisk
View File

@ -2,7 +2,6 @@ label: dos
label-id: 0x9ec19bcc
device: disk.img
unit: sectors
sector-size: 512
disk.img1 : start= 2048, size= 32768, type=6, bootable
disk.img2 : start= 34816, size= 30720, type=83

83
drivers/zero.c Normal file
View File

@ -0,0 +1,83 @@
#include "zero.h"
#include "alloc.h"
#include "kernel.h"
#include "klibc.h"
struct zeroMappedEntry {
int refCnt;
};
static int zeroOpen(struct uAddrVirtualReg *vreg)
{
struct zeroMappedEntry *ent = (struct zeroMappedEntry *)vreg->res->customData;
ent->refCnt++;
return 0;
}
static int zeroClose(struct uAddrVirtualReg *vreg)
{
struct zeroMappedEntry *ent = (struct zeroMappedEntry *)vreg->res->customData;
ent->refCnt--;
if (ent->refCnt == 0) {
free(vreg->res->customData);
free(vreg->res);
}
return 0;
}
static int zeroNoPage(struct uAddrVirtualReg *vreg, uaddr_t addr, int right)
{
(void)vreg;
int ret = 0;
paddr_t ppage = allocPhyPage(1);
ret = pageMap(ALIGN_DOWN(addr, PAGE_SIZE), ppage, right | PAGING_MEM_USER) ;
unrefPhyPage(ppage);
if (ret) {
return ret;
}
memset((void *)ALIGN_DOWN(addr, PAGE_SIZE), 0, PAGE_SIZE);
return ret;
}
static struct mappedRessourceOps zeroOps = {
.open = zeroOpen,
.close = zeroClose,
.unmap = NULL,
.nopage = zeroNoPage,
};
int zeroOnMapped(struct uAddrVirtualReg *vreg)
{
(void)vreg;
printf("ZERO MAPPED !!\n");
return 0;
}
int zeroMmap(struct uAddrSpace *as, uaddr_t *uaddr, size_t size, uint32_t rights,
uint32_t flags)
{
int ret = 0;
struct mappedRessource *res =
(struct mappedRessource *)zalloc(sizeof(struct mappedRessource));
struct zeroMappedEntry *cust =
(struct zeroMappedEntry *)zalloc(sizeof(struct zeroMappedEntry));
res->allowedRight = PAGING_MEM_READ | PAGING_MEM_WRITE | PAGING_MEM_EXEC | PAGING_MEM_USER;
res->ops = &zeroOps;
res->customData = cust;
res->onResMapped = zeroOnMapped;
ret = uAddrSpaceMmap(as, uaddr, size, rights, flags, res, 0);
if (ret) {
free(res);
free(cust);
}
return ret;
}

11
drivers/zero.h Normal file
View File

@ -0,0 +1,11 @@
#pragma once
#include "types.h"
#include "uaddrspace.h"
#include <stddef.h>
#include <stdint.h>
int zeroSetup();
int zeroMmap(struct uAddrSpace *as, uaddr_t *uaddr, size_t size, uint32_t rights, uint32_t flags);

6
userspace/kernel/syscall.h
View File

@ -1,6 +1,6 @@
#pragma once
#ifdef __KERNEL__
#include "cpu_context.h"
#include "cpu_context.h"
#endif
#define SYSCALL_ID_EXIT 1
@ -8,7 +8,9 @@
#define SYSCALL_ID_PUTC 3
#define SYSCALL_ID_READ 4
#define SYSCALL_ID_TEST 5
#define SYSCALL_ID_BRK 6
#define SYSCALL_ID_BRK 6
#define SYSCALL_ID_MMAP 7
#define SYSCALL_ID_MUNMAP 8
#ifdef __KERNEL__
int syscallExecute(int syscallId, const struct cpu_state *user_ctx);

20
userspace/libc.c
View File

@ -1,9 +1,12 @@
#include "libc.h"
#include "errno.h"
#include "list.h"
#include "minmax.h"
#include "swintr.h"
#include "sys/mman.h"
#include "syscall.h"
int errno = 0;
int memcmp(const void *aptr, const void *bptr, size_t size)
{
const unsigned char *a = (const unsigned char *)aptr;
@ -725,3 +728,20 @@ void *realloc(void *ptr, size_t size)
return new_ptr;
}
void *mmap(void *addr, size_t len, int prot, int flags, char *path) {
int ret = syscall5(SYSCALL_ID_MMAP, (unsigned int)&addr, len, prot, flags, (unsigned int)path);
if(!ret)
return addr;
errno = ret;
return MAP_FAILED;
}
int munmap(void *addr, size_t len)
{
if (len == 0)
return -EINVAL;
return syscall2(SYSCALL_ID_MUNMAP, (unsigned int)addr, len);
}

2
userspace/libc.h
View File

@ -36,6 +36,8 @@ int putc(const int c);
int vsnprintf(char *str, size_t size, const char *format, va_list ap) __attribute__ ((__format__ (printf, 3, 0)));
int vprintf(const char *format, va_list ap) __attribute__ ((__format__ (printf, 1, 0)));
int printf(const char *format, ...) __attribute__ ((__format__ (printf, 1, 2)));
void *mmap(void *addr, size_t len, int prot, int flags, char *path);
int munmap(void *addr, size_t len);
int asprintf(char **strp, const char *fmt, ...) __attribute__ ((__format__ (printf, 2, 3)));
int vasprintf(char **strp, const char *fmt, va_list ap) __attribute__ ((__format__ (printf, 2, 0)));

91
userspace/main_user.c
View File

@ -1,5 +1,8 @@
#include "errno.h"
#include "libc.h"
#include "stdarg.h"
#include "stddef.h"
#include "sys/mman.h"
#include "tiny.h"
int func_help()
@ -10,6 +13,8 @@ int func_help()
printf(" syscall5: a syscall with parameters over the stack \n");
printf(" alloc: test allocation\n");
printf(" tiny: a tiny C-like interpreter\n");
printf(" mmap: test mmap \n");
printf(" munmap: test munmap \n");
return 0;
}
@ -25,29 +30,29 @@ char *initialHeap = 0;
int func_alloc()
{
if (initialHeap == 0) {
initialHeap = sbrk(0);
initialHeap = sbrk(0);
}
printf("Testing allocation\n");
int allocSize = 4096 * 2;
char *currentHeap = sbrk(0);
if (currentHeap - initialHeap < allocSize) {
brk(initialHeap + allocSize);
brk(initialHeap + allocSize);
}
int *allocatedData = (int *)initialHeap;
for (unsigned int i = 0; i < allocSize / sizeof(int); i++) {
allocatedData[i] = i;
allocatedData[i] = i;
}
printf("Success\nTesting malloc\n");
uintptr_t heap = (uintptr_t)sbrk(0);
for (int i = 0; i < 12; i++) {
void *ptr = malloc(1 << i);
printf("malloc size %d: 0x%p\n", (1 << i), ptr);
if (ptr == NULL) {
printf("Malloc failed\n");
}
memset(ptr, 0, 1 << i);
free(ptr);
void *ptr = malloc(1 << i);
printf("malloc size %d: 0x%p\n", (1 << i), ptr);
if (ptr == NULL) {
printf("Malloc failed\n");
}
memset(ptr, 0, 1 << i);
free(ptr);
}
uintptr_t newHeap = (uintptr_t)sbrk(0);
printf("Malloc used %dB\n", newHeap - heap);
@ -55,6 +60,64 @@ int func_alloc()
return 0;
}
struct mmapedArea {
void *addr;
size_t size;
struct mmapedArea *next;
};
static struct mmapedArea *listMmap = NULL;
int func_mmap()
{
struct mmapedArea *area = (struct mmapedArea *)malloc(sizeof(struct mmapedArea));
if (area == NULL) {
printf("Fail to allocate area\n");
return -1;
}
char *path = "/dev/zero";
void *mapAddr = mmap((void *)0, 4096, PROT_READ | PROT_WRITE, 0, path);
if (mapAddr == MAP_FAILED) {
printf("mmap failed errno %d\n", errno);
return -1;
}
printf("Zero mmaped at %p\n", mapAddr);
int data = *(int *)mapAddr;
*(int *)mapAddr = data;
area->addr = mapAddr;
area->size = 4096;
area->next = listMmap;
listMmap = area;
return 0;
}
int func_munmap()
{
if (!listMmap) {
printf("Nothing to unmap... mmap first! \n");
return -1;
}
struct mmapedArea *area = listMmap;
int ret = munmap(area->addr, area->size);
if (ret) {
printf("Fail to unmap area at 0x%p (size %d) error %d\n", area->addr, area->size, ret);
return ret;
}
printf("unmap done\n");
listMmap = listMmap->next;
free(area);
return ret;
}
int main(int argc, char *argv[])
{
(void)argc;
@ -85,6 +148,14 @@ int main(int argc, char *argv[])
func_tiny();
continue;
}
if (strcmp(buf, "mmap") == 0) {
func_mmap();
continue;
}
if (strcmp(buf, "munmap") == 0) {
func_munmap();
continue;
}
}
return 0;
}

13
userspace/sys/mman.h Normal file
View File

@ -0,0 +1,13 @@
#pragma once
/* To keep in sync with PAGING_MEM_* */
#define PROT_EXEC (1<<3)
#define PROT_READ (1<<1)
#define PROT_WRITE (1<<2)
#define MAP_SHARED (1 << 0)
#define MAP_PRIVATE (1 << 1)
#define MAP_FIXED (1 << 2)
#define MAP_FAILED (void *)-1