Commit Graph

899 Commits

Author SHA1 Message Date
Zach Hilman
51af996854 ldr_ro: Add error check for memory allocation failure 2018-11-17 21:40:26 -05:00
Lioncash
d21b2164e9 kernel/errors: Clean up error codes
Similar to PR 1706, which cleans up the error codes for the filesystem
code, but done for the kernel error codes. This removes the ErrCodes
namespace and specifies the errors directly. This also fixes up any
straggling lines of code that weren't using the named error codes where
applicable.
2018-11-16 14:32:30 -05:00
Mat M
14cede1a0c
Merge pull request #1638 from FreddyFunk/SetMemoryPermission-Stubbed
Implement SetMemoryPermission
2018-11-16 10:35:56 -05:00
bunnei
f7319b0d3c
Merge pull request #1687 from lioncash/deduplication
kernel/thread: Deduplicate scheduler switching code
2018-11-15 14:47:42 -08:00
Zach Hilman
0276761a1e process: Make MirrorMemory take state to map new memory as
Credits to Subv
2018-11-15 12:48:09 -05:00
bunnei
e1ea8cc721
Merge pull request #1679 from DarkLordZach/deterministic-rng-2
svc: Use proper random entropy generation algorithm
2018-11-14 11:52:27 -08:00
Lioncash
f9db75fe40 kernel/thread: Deduplicate scheduler switching code
The code in both places was the same verbatim, so we can extract it to a
function to deduplicate the logic.
2018-11-14 00:02:42 -05:00
Lioncash
004277477a vm_manager: Unstub GetTotalHeapUsage()
Now that we've moved all of the heap-related stuff to the VMManager
class, we can unstub this function, as the necessary members are visible
now.
2018-11-13 13:08:26 -05:00
Lioncash
b8e885c6e5 kernel/process: Migrate heap-related memory management out of the process class and into the vm manager
Avoids a breach of responsibilities in the interface and keeps the
direct code for memory management within the VMManager class.
2018-11-13 13:08:19 -05:00
Zach Hilman
ab552e4a25 svc: Use proper random entropy generation algorithm 2018-11-13 12:26:03 -05:00
Zach Hilman
cb1e63ef09 svc: Return random seed for svcGetInfo RandomEntropy 2018-11-12 21:46:21 -05:00
David
581406af18 svcBreak now dumps information from the debug buffer passed (#1646)
* svcBreak now dumps information from the debug buffer passed

info1 and info2 seem to somtimes hold an address to a buffer, this is usually 4 bytes or the size of the int and contains an error code. There's other circumstances where it can be something different so we hexdump these to examine them at a later date.

* Addressed comments
2018-11-07 20:43:54 -08:00
Frederic Laing
ba2cdcdc5a Implement SetMemoryPermission 2018-11-06 10:21:01 +01:00
Frederic Laing
ab7472345b Stubbed SetMemoryPermission 2018-11-03 16:01:34 +01:00
Lioncash
352b56367c general: Remove unused boost inclusions where applicable
Cleans up unused includes and trims off some dependencies on externals.
2018-10-30 00:09:46 -04:00
Frederic L
7a5eda5914 global: Use std::optional instead of boost::optional (#1578)
* get rid of boost::optional

* Remove optional references

* Use std::reference_wrapper for optional references

* Fix clang format

* Fix clang format part 2

* Adressed feedback

* Fix clang format and MacOS build
2018-10-30 00:03:25 -04:00
bunnei
adf26ae668
Merge pull request #1621 from lioncash/ipc
hle_ipc: Make GetDomainMessageHeader return a regular pointer
2018-10-29 23:55:59 -04:00
Lioncash
6383653a8d hle_ipc: Add member function for querying the existence of a domain header
Gets rid of the need to call the getter and then check for null.
2018-10-29 23:28:04 -04:00
Lioncash
0cc347462d hle_ipc: Make GetDomainMessageHeader return a regular pointer
Nothing requires the shared owner ship here, so we can just return a
plain pointer.
2018-10-29 23:18:25 -04:00
Lioncash
a973a049b7 core: Make System references const where applicable 2018-10-28 17:45:29 -04:00
Lioncash
7de8e36343 svc: Localize the GetInfo enum class to the function itself
Nothing from this enum is intended to be used outside of this function.
2018-10-26 12:49:14 -04:00
Lioncash
6594853eb1 svc: Implement svcGetInfo command 0xF0000002
This retrieves:

if (curr_thread == handle_thread) {
   result = total_thread_ticks + (hardware_tick_count - last_context_switch_ticks);
} else if (curr_thread == handle_thread && sub_id == current_core_index) {
   result = hardware_tick_count - last_context_switch_ticks;
}
2018-10-26 12:49:11 -04:00
bunnei
c2049aa4e5 process: LoadModule should clear JIT instruction cache. 2018-10-25 18:03:54 -04:00
bunnei
a609b6907a Kernel/Memory: Added a function to first a suitable guest address at which to allocate a region of a given size. 2018-10-25 18:03:54 -04:00
Lioncash
1fb4bebb63 kernel/errors: Remove now-unused, unnecessary, error codes
Now that we've gotten the innaccurate error codes out of the way, we can
finally toss away a bunch of these, trimming down the error codes to
ones that are actually used and knocking out two TODO comments.
2018-10-24 14:58:37 -04:00
Lioncash
239dfea34a kernel/shared_memory: Return ERR_INVALID_MEMORY_PERMISSIONS instead of ERR_INVALID_COMBINATION
This is more consistent with what the kernel does.
2018-10-24 14:54:36 -04:00
Lioncash
474bc29208 kernel/server_port: Simplify emptiness check within ShouldWait() 2018-10-24 14:24:36 -04:00
Lioncash
b703aba622 kernel/server_port: Change error case return value in Accept() to ERR_NOT_FOUND
This is what the kernel does in this instance.
2018-10-24 14:23:38 -04:00
Lioncash
afb7e5cc05 kernel/error: Remove leftover 3DS error codes
These are now entirely unused and can be removed.
2018-10-24 14:21:37 -04:00
Lioncash
fcf8f53a63 kernel/svc: Amend returned error code for invalid priorities in CreateThread
Like with the previous change, the kernel doesn't return NOT_AUTHORIZED
here. It returns INVALID_THREAD_PRIORITY.
2018-10-24 14:11:11 -04:00
Lioncash
77328b0f19 kernel/svc: Move and correct returned error code for invalid thread priorities in SetThreadPriority()
All priority checks are supposed to occur before checking the validity
of the thread handle, we're also not supposed to return
ERR_NOT_AUTHORIZED here.
2018-10-24 14:10:48 -04:00
Lioncash
c7c346a15d kernel/error: Add error code for invalid pointers
The kernel appears to return 0xE601 for this situation. Particularly in
svcWaitSynchronization, svcReplyAndReceive, and svcGetThreadContext
2018-10-24 13:41:32 -04:00
Lioncash
6df09f5b76 kernel/error: Add error code for closed sessions
The kernel appears to return 0xF601 for this case.
2018-10-24 13:38:39 -04:00
bunnei
a94e5d9e68
Merge pull request #1551 from ogniK5377/improved-svcbreak
Added break types to svcBreak
2018-10-23 19:56:42 -04:00
bunnei
e61a62066a
Merge pull request #1540 from lioncash/handle
kernel/process: Make the handle table per-process
2018-10-23 18:43:11 -04:00
David Marcec
38cdb6744d Added assertion failed, reworked logging levels 2018-10-23 15:17:13 +11:00
David Marcec
8042731da9 Added break types to svcBreak
There seems to be more such as type 1, and 2. Unsure what these currently are but when a game hits them we can investigate and add the rest
2018-10-23 15:03:59 +11:00
Lioncash
90a981a03a kernel/process: Make the handle table per-process
In the kernel, there isn't a singular handle table that everything gets
tossed into or used, rather, each process gets its own handle table that
it uses. This currently isn't an issue for us, since we only execute one
process at the moment, but we may as well get this out of the way so
it's not a headache later on.
2018-10-20 16:38:32 -04:00
Lioncash
896c0f61a0 svc: Fix vma boundary check in svcQueryMemory
This should be comparing against the queried process' vma_map, not the
current process'. The only reason this hasn't become an issue yet is we
currently only handle one process being active at any time.
2018-10-20 14:56:51 -04:00
bunnei
60317e6306
Merge pull request #1520 from lioncash/san
svc: Add missing sanitizing checks for MapSharedMemory/UnmapSharedMemory
2018-10-19 22:58:57 -04:00
Lioncash
4b5ae8dbaa svc: Check for word alignment of addresses within svcArbitrateLock/svcArbitrateUnlock
The kernel itself checks whether or not the provided addresses are word
aligned before continuing, so we should be doing the same.
2018-10-18 13:01:29 -04:00
Lioncash
d27f4a4928 common: Move Is4KBAligned() to alignment.h
Aligning on 4KB pages isn't a Switch-specific thing, so this can be
moved to common so it can be used with other things as well.
2018-10-18 12:57:02 -04:00
Lioncash
33830aa65a svc: Add missing sanitizing checks for MapSharedMemory/UnmapSharedMemory
Now that the changes clarifying the address spaces has been merged, we
can wrap the checks that the kernel performs when mapping shared memory
(and other forms of memory) into its own helper function and then use
those within MapSharedMemory and UnmapSharedMemory to complete the
sanitizing checks that are supposed to be done.
2018-10-18 02:01:21 -04:00
bunnei
6e8752881c
Merge pull request #1498 from lioncash/aslr
svc: Clarify enum values for AddressSpaceBaseAddr and AddressSpaceSize in svcGetInfo()
2018-10-17 18:31:51 -04:00
Lioncash
5484742fda core_cpu: Make Cpu scheduler instances unique_ptrs instead of shared_ptrs 2018-10-15 14:15:56 -04:00
Lioncash
90f8474fc1 svc: Clarify enum values for AddressSpaceBaseAddr and AddressSpaceSize in svcGetInfo()
So, one thing that's puzzled me is why the kernel seemed to *not* use
the direct code address ranges in some cases for some service functions.
For example, in svcMapMemory, the full address space width is compared
against for validity, but for svcMapSharedMemory, it compares against
0xFFE00000, 0xFF8000000, and 0x7FF8000000 as upper bounds, and uses
either 0x200000 or 0x8000000 as the lower-bounds as the beginning of the
compared range. Coincidentally, these exact same values are also used in
svcGetInfo, and also when initializing the user address space, so this
is actually retrieving the ASLR extents, not the extents of the address
space in general.
2018-10-14 20:11:16 -04:00
bunnei
2f8ca32020
Merge pull request #1492 from lioncash/proc
svc: Implement svcGetProcessInfo
2018-10-14 14:37:58 -04:00
David Marcec
92fae7e1ab Stop all threads on svcBreak
This should help diagnose crashes easier and prevent many users thinking that a game is still running when in fact it's just an audio thread still running(this is typically not killed when svcBreak is hit since the game expects us to do this)
2018-10-14 18:14:51 +11:00
Lioncash
1c7a7ed79b svc: Implement svcGetProcessInfo
A fairly basic service function, which only appears to currently support
retrieving the process state. This also alters the ProcessStatus enum to
contain all of the values that a kernel process seems to be able of
reporting with regards to state.
2018-10-13 17:00:43 -04:00
bunnei
c2aa4293ec
Merge pull request #1483 from lioncash/codeset
kernel/process: Make CodeSet a regular non-inherited object
2018-10-12 22:52:12 -04:00
bunnei
ffcda6c08e
Merge pull request #1481 from lioncash/typo
svc: Fix typos in sanitizing checks for MapMemory/UnmapMemory
2018-10-12 20:46:55 -04:00
bunnei
2946d4bdbe
Merge pull request #1467 from ogniK5377/svcbreak-type-fix
Fixed incorrect types for svcBreak
2018-10-12 12:08:08 -04:00
Lioncash
1abed2f4c4 kernel/process: Make CodeSet a regular non-inherited object
These only exist to ferry data into a Process instance and end up going
out of scope quite early. Because of this, we can just make it a plain
struct for holding things and just std::move it into the relevant
function. There's no need to make this inherit from the kernel's Object
type.
2018-10-12 12:07:32 -04:00
Lioncash
b492d43e63 thread: Remove unnecessary memset from ResetThreadContext()
Regular value initialization is adequate here for zeroing out data. It
also has the benefit of not invoking undefined behavior if a non-trivial
type is ever added to the struct for whatever reason.
2018-10-12 10:57:31 -04:00
Lioncash
4ccf30dfaa svc: Fix typos in sanitizing checks for MapMemory/UnmapMemory 2018-10-12 01:48:26 -04:00
Lioncash
72e9cb523e svc: Add missing address range sanitizing checks to MapMemory/UnmapMemory
This adds the missing address range checking that the service functions
do before attempting to map or unmap memory. Given that both service
functions perform the same set of checks in the same order, we can wrap
these into a function and just call it from both functions, which
deduplicates a little bit of code.
2018-10-10 20:30:49 -04:00
Lioncash
5c0408596f kernel/thread: Use a regular pointer for the owner/current process
There's no real need to use a shared pointer in these cases, and only
makes object management more fragile in terms of how easy it would be to
introduce cycles. Instead, just do the simple thing of using a regular
pointer. Much of this is just a hold-over from citra anyways.

It also doesn't make sense from a behavioral point of view for a
process' thread to prolong the lifetime of the process itself (the
process is supposed to own the thread, not the other way around).
2018-10-10 02:04:55 -04:00
David Marcec
2db37ddea9 Changed all casts in svc_wrap.h to be static_cast instead 2018-10-10 12:49:08 +11:00
David Marcec
09b6dda8f0 Use a better name than "dont_kill_application"
signal_debugger seems like a more fitting name
2018-10-10 12:27:44 +11:00
David Marcec
a4412c8e22 Fixed incorrect types for svcBreak
svcBreak reason should be a u32, not a u64.
2018-10-10 12:23:50 +11:00
David Marcec
f5631e78d1 Added bitfield instead of manually checking if the bit is set 2018-10-09 12:11:14 +11:00
David Marcec
af3ba94b2a Actual kill execution when the bit isn't set, not the other way around 2018-10-09 11:14:48 +11:00
David Marcec
c50f66a8eb svcBreak, Signalling to the debugger should not kill execution
When loading NROs, svcBreak is called to signal to the debugger that a new "module" is loaded. As no debugger is technically attached we shouldn't be killing the programs execution.
2018-10-09 11:10:30 +11:00
David Marcec
612ce89eca Added forward define for ServerPort 2018-10-06 17:47:33 +10:00
David Marcec
f84b9ed4e8 Ported #4296 from citra
This will allow us to easily remove the use of "NFC" in "System"
2018-10-06 16:49:01 +10:00
Lioncash
6ddf8f34db
kernel/mutex: Amend behavior of TransferMutexOwnership()
This was the result of a typo accidentally introduced in
e51d715700. This restores the previous
correct behavior.

The behavior with the reference was incorrect and would cause some games
to fail to boot.
2018-10-06 01:13:02 -04:00
balika011
1a5d6de0d4 thread: Make the scheduler pointer a regular pointer
Conceptually, it doesn't make sense for a thread to be able to persist
the lifetime of a scheduler. A scheduler should be taking care of the
threads; the threads should not be taking care of the scheduler.

If the threads outlive the scheduler (or we simply don't actually
terminate/shutdown the threads), then it should be considered a bug
that we need to fix.

Attributing this to balika011, as they opened #1317 to attempt to fix
this in a similar way, but my refactoring of the kernel code caused
quite a few conflicts.
2018-10-05 14:53:01 -04:00
Lioncash
baed7e1fba kernel/thread: Make all instance variables private
Many of the member variables of the thread class aren't even used
outside of the class itself, so there's no need to make those variables
public. This change follows in the steps of the previous changes that
made other kernel types' members private.

The main motivation behind this is that the Thread class will likely
change in the future as emulation becomes more accurate, and letting
random bits of the emulator access data members of the Thread class
directly makes it a pain to shuffle around and/or modify internals.
Having all data members public like this also makes it difficult to
reason about certain bits of behavior without first verifying what parts
of the core actually use them.

Everything being public also generally follows the tendency for changes
to be introduced in completely different translation units that would
otherwise be better introduced as an addition to the Thread class'
public interface.
2018-10-04 00:14:15 -04:00
Lioncash
541c550753 kernel/svc: Implement svcGetThreadContext()
Now that we have all of the rearranging and proper structure sizes in
place, it's fairly trivial to implement svcGetThreadContext(). In the
64-bit case we can more or less just write out the context as is, minus
some minor value sanitizing. In the 32-bit case we'll need to clear out
the registers that wouldn't normally be accessible from a 32-bit
AArch32 exectuable (or process).
2018-09-30 05:29:40 -04:00
Lioncash
dccfe193a9 kernel/process: Add a data member to determine if a process is 64-bit or not.
This will be necessary for the implementation of svcGetThreadContext(),
as the kernel checks whether or not the process that owns the thread
that has it context being retrieved is a 64-bit or 32-bit process.

If the process is 32-bit, then the upper 15 general-purpose registers
and upper 16 vector registers are cleared to zero (as AArch32 only has
15 GPRs and 16 128-bit vector registers. not 31 general-purpose
registers and 32 128-bit vector registers like AArch64).
2018-09-30 05:29:40 -04:00
Lioncash
cf9d6c6f52 kernel/process: Make data member variables private
Makes the public interface consistent in terms of how accesses are done
on a process object. It also makes it slightly nicer to reason about the
logic of the process class, as we don't want to expose everything to
external code.
2018-09-30 02:30:01 -04:00
bunnei
97c0ac3545
Merge pull request #1412 from lioncash/move
kernel/object: Remove unnecessary std::move from DynamicObjectCast()
2018-09-29 11:58:58 -04:00
bunnei
f7b69d61f2
Merge pull request #1395 from lioncash/vm
process/vm_manager: Initial modifications to load NPDM metadata
2018-09-29 10:54:39 -04:00
Lioncash
f4c24d0832 kernel/object: Remove unnecessary std::move from DynamicObjectCast()
boost::static_pointer_cast for boost::intrusive_ptr (what SharedPtr is),
takes its parameter by const reference. Given that, it means that this
std::move doesn't actually do anything other than obscure what the
function's actual behavior is, so we can remove this. To clarify, this
would only do something if the parameter was either taking its argument
by value, by non-const ref, or by rvalue-reference.
2018-09-28 02:17:57 -04:00
bunnei
c0445006af
Merge pull request #1399 from lioncash/sched
kernel/scheduler: Take ARM_Interface instances by reference
2018-09-26 16:17:18 -04:00
Lioncash
a58eefa7e4 kernel/scheduler: Take ARM_Interface instance by reference in the constructor
It doesn't make sense to allow a scheduler to be constructed around a
null pointer.
2018-09-25 16:00:17 -04:00
bunnei
b67c1fdf38
Merge pull request #1393 from tech4me/svc
svc: Updated svc names
2018-09-25 10:47:12 -04:00
Lioncash
83377113bf memory: Dehardcode the use of fixed memory range constants
The locations of these can actually vary depending on the address space
layout, so we shouldn't be using these when determining where to map
memory or be using them as offsets for calculations. This keeps all the
memory ranges flexible and malleable based off of the virtual memory
manager instance state.
2018-09-24 22:16:03 -04:00
Lioncash
6c6f95d071 svc: Report correct memory-related values within some of the cases in svcGetInfo()
Previously, these were reporting hardcoded values, but given the regions
can change depending on the requested address spaces, these need to
report the values that the memory manager contains.
2018-09-24 22:16:03 -04:00
Lioncash
7fd598636e memory: Dehardcode the use of a 36-bit address space
Given games can also request a 32-bit or 39-bit address space, we
shouldn't be hardcoding the address space range as 36-bit.
2018-09-24 22:15:53 -04:00
Lioncash
75603b005b process/vm_manager: Amend API to allow reading parameters from NPDM metadata
Rather than hard-code the address range to be 36-bit, we can derive the
parameters from supplied NPDM metadata if the supplied exectuable
supports it. This is the bare minimum necessary for this to be possible.

The following commits will rework the memory code further to adjust to
this.
2018-09-24 17:24:50 -04:00
tech4me
d42424ace0 svc: Updated svc names 2018-09-23 17:03:38 -07:00
Lioncash
48b2eda492 svc: Move most process termination code to its own function within Process
Reduces the use of Process class members externally and keeps most code
related to tearing down a process with the rest of the process code.
2018-09-21 06:07:41 -04:00
Lioncash
acfc801d14 thread/process: Move TLS slot marking/freeing to the process class
Allows making several members of the process class private, it also
avoids going through Core::CurrentProcess() just to retrieve the owning
process.
2018-09-21 03:50:12 -04:00
bunnei
0285ddfbd4
Merge pull request #1372 from lioncash/thread
kernel/thread: Use owner_process when setting the page table in SetupMainThread()
2018-09-20 23:35:29 -04:00
Lioncash
05aa4aa01a kernel/thread: Use owner_process when setting the page table in SetupMainThread()
The owning process of a thread is required to exist before the thread,
so we can enforce this API-wise by using a reference. We can also avoid
the reliance on the system instance by using that parameter to access
the page table that needs to be set.
2018-09-20 21:10:00 -04:00
Lioncash
9b8fc2b689 arm_interface: Replace kernel vm_manager include with a forward declaration
Avoids an unnecessary inclusion and also uncovers three places where
indirect inclusions were relied upon, which allows us to also resolve
those.
2018-09-20 19:35:36 -04:00
bunnei
c768535463
Merge pull request #1346 from lioncash/svc
svc_wrap: Convert the PARAM macro into a function
2018-09-18 22:12:47 -04:00
bunnei
733c47623b
Merge pull request #1343 from lioncash/mutex
kernel/svc: Handle invalid address cases within svcArbitrateLock() and svcArbitrateUnlock()
2018-09-18 14:25:00 -04:00
Lioncash
f85ab0a123 svc_wrap: Convert the PARAM macro into a function
This can just be a regular function, getting rid of the need to also
explicitly undef the define at the end of the file. Given FuncReturn()
was already converted into a function, it's #undef can also be removed.
2018-09-18 04:27:38 -04:00
Lioncash
b51e7e0288 arm_interface: Remove ARM11-isms from the CPU interface
This modifies the CPU interface to more accurately match an
AArch64-supporting CPU as opposed to an ARM11 one. Two of the methods
don't even make sense to keep around for this interface, as Adv Simd is
used, rather than the VFP in the primary execution state. This is
essentially a modernization change that should have occurred from the
get-go.
2018-09-18 03:20:04 -04:00
Lioncash
71b48cb00f kernel/mutex: Replace ResultCode construction for invalid addresses with the named variant
We already have a ResultCode constant for the case of an invalid
address, so we can just use it instead of re-rolling that ResultCode
type.
2018-09-17 23:27:53 -04:00
Lioncash
b6867602ca kernel/svc: Handle error cases for svcArbitrateLock() and svcArbitrateUnlock()
The kernel does the equivalent of the following check before proceeding:

if (address + 0x8000000000 < 0x7FFFE00000) {
    return ERR_INVALID_MEMORY_STATE;
}

which is essentially what our IsKernelVirtualAddress() function does. So
we should also be checking for this.

The kernel also checks if the given input addresses are 4-byte aligned,
however our Mutex::TryAcquire() and Mutex::Release() functions already
handle this, so we don't need to add code for this case.
2018-09-17 23:27:53 -04:00
bunnei
2bfb9fd0e6
Merge pull request #1313 from lioncash/error
kernel/errors: Amend error code for ERR_NOT_FOUND
2018-09-17 12:28:40 -04:00
bunnei
e6367ab955
Merge pull request #1315 from lioncash/size
kernel/svc: Handle a few error cases within memory-related functions
2018-09-17 10:11:26 -04:00
bunnei
e561afdcd5
Merge pull request #1328 from FearlessTobi/port-4192
Port #4192 from Citra: "svc: change unknown to thread in CreateThread"
2018-09-17 09:56:48 -04:00
Valentin Vanelslande
54ddb37b3c Port # #4192 from Citra: "svc: change unknown to thread in CreateThread" 2018-09-15 15:28:35 +02:00
fearlessTobi
63c2e32e20 Port #4182 from Citra: "Prefix all size_t with std::" 2018-09-15 15:21:06 +02:00
Lioncash
4f8756edd0 kernel/svc: Sanitize creation of shared memory via svcCreateSharedMemory()
The kernel caps the size limit of shared memory to 8589930496 bytes (or
(1GB - 512 bytes) * 8), so approximately 8GB, where every GB has a 512
byte sector taken off of it.

It also ensures the shared memory is created with either read or
read/write permissions for both permission types passed in, allowing the
remote permissions to also be set as "don't care".
2018-09-13 23:07:27 -04:00
Lioncash
accd1f17e4 kernel/svc: Sanitize addresses, permissions, and sizes within svcMapSharedMemory() and svcUnmapSharedMemory()
Part of the checking done by the kernel is to check if the given
address and size are 4KB aligned, as well as checking if the size isn't
zero. It also only allows mapping shared memory as readable or
read/write, but nothing else, and so we shouldn't allow mapping as
anything else either.
2018-09-13 23:07:23 -04:00