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Add the ability to map/unmap a ressource

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This commit is contained in:
Mathieu Maret 2024-01-31 23:49:07 +01:00 committed by Mathieu Maret
parent 26881d2728
commit 78cf247cd4
5 changed files with 264 additions and 22 deletions
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3
core/syscall.c
View File

@ -74,8 +74,9 @@ int syscallExecute(int syscallId, const struct cpu_state *userCtx)
strzcpyFromUser((vaddr_t *)path, (uaddr_t *)userPath, sizeof(path));
printf("Trying mmap for device %s\n", path);
if(strcmp(path, "/dev/zero") == 0){
zeroMmap(as, &uaddr, size, rights,flags);
ret = zeroMmap(as, &uaddr, size, rights,flags);
}
printf("ret %d\n", ret);
(void)as;
break;
}

242
core/uaddrspace.c
View File

@ -24,6 +24,82 @@ struct uAddrSpace {
size_t heapSize; // Heap size -> modified by brk()
};
static int hasOverlap(uaddr_t addr1, size_t size1, uaddr_t addr2, size_t size2)
{
return max(addr1, addr2) < min(addr1 + size1, addr2 + size2);
}
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)
{
@ -61,6 +137,91 @@ int uAddrSpaceDelete(struct uAddrSpace *addr)
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 (!ALIGN(uaddr, PAGE_SIZE) || size <= 0)
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->close)
reg->res->ops->close(reg);
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;
@ -137,14 +298,77 @@ free_ppage:
return -1;
}
int uAddrSpaceMmap(struct uAddrSpace *as, uaddr_t *uaddr, size_t size, uint32_t rights, uint32_t flags,
struct mappedRessource *res)
int uAddrSpaceMmap(struct uAddrSpace *as, uaddr_t *uaddr, size_t size, uint32_t rights,
uint32_t flags, struct mappedRessource *res, uint32_t offset )
{
(void)as;
(void)uaddr;
(void)rights;
(void)size;
(void)flags;
(void)res;
return 0;
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;
}
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;
}

8
core/uaddrspace.h
View File

@ -7,6 +7,8 @@
struct uAddrSpace;
struct uAddrVirtualReg;
#define UA_MAP_SHARED (1 << 0)
#define UA_MAP_FIXED (1 << 1)
// TODO : move this struct to .c and add accessors
struct uAddrVirtualReg {
uaddr_t addr;
@ -33,6 +35,7 @@ struct mappedRessource {
struct mappedRessourceOps *ops;
struct uAddrVirtualReg *listVirtualReg;
void *customData;
int (*onResMapped)(struct uAddrVirtualReg *reg); // Callabck for when the ressourced get mapped
};
@ -43,5 +46,6 @@ int uAddrSpaceSetHeap(struct uAddrSpace *as, uaddr_t addr, size_t size);
int uAddrSpaceCheckNAlloc(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);
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);

32
drivers/zero.c
View File

@ -1,5 +1,6 @@
#include "zero.h"
#include "alloc.h"
#include "klibc.h"
#include "zero.h"
struct zeroMappedEntry {
int refCnt;
@ -30,16 +31,27 @@ static struct mappedRessourceOps zeroOps = {
.nopage = zeroNoPage,
};
int zeroMmap(struct uAddrSpace *as, uaddr_t *uaddr, size_t size, uint32_t rights, uint32_t flags)
int zeroOnMapped(struct uAddrVirtualReg *vreg)
{
struct mappedRessource *res = (struct mappedRessource *)zalloc(sizeof(struct mappedRessource));
struct zeroMappedEntry *cust = (struct zeroMappedEntry *)zalloc(sizeof(struct zeroMappedEntry));
(void)vreg;
res->allowedRight = PAGING_MEM_READ | PAGING_MEM_WRITE | PAGING_MEM_EXEC | PAGING_MEM_USER;
res->ops = &zeroOps;
res->customData = cust;
printf("ZERO MAPPED !!\n");
uAddrSpaceMmap(as, uaddr, size, rights, flags, res);
return 0;
return 0;
}
int zeroMmap(struct uAddrSpace *as, uaddr_t *uaddr, size_t size, uint32_t rights,
uint32_t flags)
{
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;
return uAddrSpaceMmap(as, uaddr, size, rights, flags, res, 0);
}

1
userspace/main_user.c
View File

@ -10,6 +10,7 @@ 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");
return 0;
}