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kernel/vm: Add user address checks to mlock routines.

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Also adjust general checks at the beginning. Patterned after
_user_set_memory_protection.
This commit is contained in:
Augustin Cavalier 2022-03-24 12:56:31 -04:00
parent 760270af02
commit 69b5103b54
1 changed files with 26 additions and 29 deletions
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55
src/system/kernel/vm/vm.cpp
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@ -6969,19 +6969,18 @@ struct LockedPages : DoublyLinkedListLinkImpl<LockedPages> {
status_t
_user_mlock(const void* address, size_t size)
_user_mlock(const void* _address, size_t size)
{
if (size == 0)
return B_OK;
// check address range
addr_t address = (addr_t)_address;
size = PAGE_ALIGN(size);
// Make sure the address is multiple of B_PAGE_SIZE (POSIX allows us to
// reject the call otherwise)
if ((addr_t)address % B_PAGE_SIZE != 0)
if ((address % B_PAGE_SIZE) != 0)
return EINVAL;
if (!validate_user_memory_range(_address, size))
return EINVAL;
size = ROUNDUP(size, B_PAGE_SIZE);
addr_t endAddress = (addr_t)address + size;
addr_t endAddress = address + size;
// Pre-allocate a linked list element we may need (it's simpler to do it
// now than run out of memory in the midle of changing things)
@ -7000,13 +6999,13 @@ _user_mlock(const void* address, size_t size)
// Locate the first locked range possibly overlapping ours
LockedPages* currentRange = lockedPages->Head();
while (currentRange != NULL && currentRange->end <= (addr_t)address)
while (currentRange != NULL && currentRange->end <= address)
currentRange = lockedPages->GetNext(currentRange);
if (currentRange == NULL || currentRange->start >= endAddress) {
// No existing range is overlapping with ours. We can just lock our
// range and stop here.
newRange->start = (addr_t)address;
newRange->start = address;
newRange->end = endAddress;
error = newRange->LockMemory();
if (error != B_OK)
@ -7019,7 +7018,7 @@ _user_mlock(const void* address, size_t size)
// We get here when there is at least one existing overlapping range.
if (currentRange->start <= (addr_t)address) {
if (currentRange->start <= address) {
if (currentRange->end >= endAddress) {
// An existing range is already fully covering the pages we need to
// lock. Nothing to do then.
@ -7027,7 +7026,7 @@ _user_mlock(const void* address, size_t size)
} else {
// An existing range covers the start of the area we want to lock.
// Advance our start address to avoid it.
address = (void*)currentRange->end;
address = currentRange->end;
// Move on to the next range for the next step
currentRange = lockedPages->GetNext(currentRange);
@ -7035,7 +7034,7 @@ _user_mlock(const void* address, size_t size)
}
// First, lock the new range
newRange->start = (addr_t)address;
newRange->start = address;
newRange->end = endAddress;
error = newRange->LockMemory();
if (error != B_OK)
@ -7062,7 +7061,7 @@ _user_mlock(const void* address, size_t size)
if (currentRange != NULL) {
// One last range may cover the end of the area we're trying to lock
if (currentRange->start == (addr_t)address) {
if (currentRange->start == address) {
// In case two overlapping ranges (one at the start and the other
// at the end) already cover the area we're after, there's nothing
// more to do. So we destroy our new extra allocation
@ -7089,20 +7088,18 @@ _user_mlock(const void* address, size_t size)
status_t
_user_munlock(const void* address, size_t size)
_user_munlock(const void* _address, size_t size)
{
if (size == 0)
return B_OK;
// check address range
addr_t address = (addr_t)_address;
size = PAGE_ALIGN(size);
// Make sure the address is multiple of B_PAGE_SIZE (POSIX allows us to
// reject the call otherwise)
if ((addr_t)address % B_PAGE_SIZE != 0)
if ((address % B_PAGE_SIZE) != 0)
return EINVAL;
if (!validate_user_memory_range(_address, size))
return EINVAL;
// Round size up to the next page
size = ROUNDUP(size, B_PAGE_SIZE);
addr_t endAddress = (addr_t)address + size;
addr_t endAddress = address + size;
// Get and lock the team
Team* team = thread_get_current_thread()->team;
@ -7114,7 +7111,7 @@ _user_munlock(const void* address, size_t size)
// Locate the first locked range possibly overlapping ours
LockedPages* currentRange = lockedPages->Head();
while (currentRange != NULL && currentRange->end <= (addr_t)address)
while (currentRange != NULL && currentRange->end <= address)
currentRange = lockedPages->GetNext(currentRange);
if (currentRange == NULL || currentRange->start >= endAddress) {
@ -7122,7 +7119,7 @@ _user_munlock(const void* address, size_t size)
return B_OK;
}
if (currentRange->start < (addr_t)address) {
if (currentRange->start < address) {
if (currentRange->end > endAddress) {
// There is a range fully covering the area we want to unlock,
// and it extends on both sides. We need to split it in two
@ -7139,7 +7136,7 @@ _user_munlock(const void* address, size_t size)
return error;
}
error = currentRange->Move(currentRange->start, (addr_t)address);
error = currentRange->Move(currentRange->start, address);
if (error != B_OK) {
delete newRange;
return error;
@ -7150,7 +7147,7 @@ _user_munlock(const void* address, size_t size)
} else {
// There is a range that overlaps and extends before the one we
// want to unlock, we need to shrink it
error = currentRange->Move(currentRange->start, (addr_t)address);
error = currentRange->Move(currentRange->start, address);
if (error != B_OK)
return error;
}