Commit graph

22 commits

Author SHA1 Message Date
Andrew Boie be919d3bf7 userspace: improve dynamic object allocation
We now have a low-level function z_dynamic_object_create()
which is not a system call and is used for installing
kernel objects that are not supported by k_object_alloc().

Checking for valid object type enumeration values moved
completely to the implementation function.

A few debug messages and comments were improved.

Futexes and sys_mutexes are now properly excluded from
dynamic generation.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2020-06-03 22:33:32 +02:00
Andrew Boie 2dc2ecfb60 kernel: rename struct _k_object
Private type, internal to the kernel, not directly associated
with any k_object_* APIs. Is the return value of z_object_find().
Rename to struct z_object.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2020-03-17 20:11:27 +02:00
Andrew Boie 4bad34e749 kernel: rename _k_thread_stack_element
Private data type, prefix with z_.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2020-03-17 20:11:27 +02:00
Andrew Boie cb1dd7465b kernel: remove vestigal printk references
Logging is now used for these situations.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2019-10-01 16:15:06 -05:00
Andy Ross 643701aaf8 kernel: syscalls: Whitespace fixups
The semi-automated API changes weren't checkpatch aware.  Fix up
whitespace warnings that snuck into the previous patches.  Really this
should be squashed, but that's somewhat difficult given the structure
of the series.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2019-09-12 11:31:50 +08:00
Andy Ross 6564974bae userspace: Support for split 64 bit arguments
System call arguments, at the arch layer, are single words.  So
passing wider values requires splitting them into two registers at
call time.  This gets even more complicated for values (e.g
k_timeout_t) that may have different sizes depending on configuration.
This patch adds a feature to gen_syscalls.py to detect functions with
wide arguments and automatically generates code to split/unsplit them.

Unfortunately the current scheme of Z_SYSCALL_DECLARE_* macros won't
work with functions like this, because for N arguments (our current
maximum N is 10) there are 2^N possible configurations of argument
widths.  So this generates the complete functions for each handler and
wrapper, effectively doing in python what was originally done in the
preprocessor.

Another complexity is that traditional the z_hdlr_*() function for a
system call has taken the raw list of word arguments, which does not
work when some of those arguments must be 64 bit types.  So instead of
using a single Z_SYSCALL_HANDLER macro, this splits the job of
z_hdlr_*() into two steps: An automatically-generated unmarshalling
function, z_mrsh_*(), which then calls a user-supplied verification
function z_vrfy_*().  The verification function is typesafe, and is a
simple C function with exactly the same argument and return signature
as the syscall impl function.  It is also not responsible for
validating the pointers to the extra parameter array or a wide return
value, that code gets automatically generated.

This commit includes new vrfy/msrh handling for all syscalls invoked
during CI runs.  Future commits will port the less testable code.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2019-09-12 11:31:50 +08:00
Patrik Flykt 4344e27c26 all: Update reserved function names
Update reserved function names starting with one underscore, replacing
them as follows:
   '_k_' with 'z_'
   '_K_' with 'Z_'
   '_handler_' with 'z_handl_'
   '_Cstart' with 'z_cstart'
   '_Swap' with 'z_swap'

This renaming is done on both global and those static function names
in kernel/include and include/. Other static function names in kernel/
are renamed by removing the leading underscore. Other function names
not starting with any prefix listed above are renamed starting with
a 'z_' or 'Z_' prefix.

Function names starting with two or three leading underscores are not
automatcally renamed since these names will collide with the variants
with two or three leading underscores.

Various generator scripts have also been updated as well as perf,
linker and usb files. These are
   drivers/serial/uart_handlers.c
   include/linker/kobject-text.ld
   kernel/include/syscall_handler.h
   scripts/gen_kobject_list.py
   scripts/gen_syscall_header.py

Signed-off-by: Patrik Flykt <patrik.flykt@intel.com>
2019-03-11 13:48:42 -04:00
Flavio Ceolin 76b3518ce6 kernel: Make statements evaluate boolean expressions
MISRA-C requires that the if statement has essentially Boolean type.

MISRA-C rule 14.4

Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
2019-01-07 08:52:07 -05:00
Flavio Ceolin 92ea2f9189 kernel: Calling Z_SYSCALL_VERIFY_MSG with boolean expressions
Explicitly making a boolean expression when calling
Z_SYSCALL_VERIFY_MSG macro.

MISRA-C rule: 14.4

Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
2018-09-28 06:28:41 +05:30
Andrew Boie 8345e5ebf0 syscalls: remove policy from handler checks
The various macros to do checks in system call handlers all
implictly would generate a kernel oops if a check failed.
This is undesirable for a few reasons:

* System call handlers that acquire resources in the handler
  have no good recourse for cleanup if a check fails.
* In some cases we may want to propagate a return value back
  to the caller instead of just killing the calling thread,
  even though the base API doesn't do these checks.

These macros now all return a value, if nonzero is returned
the check failed. K_OOPS() now wraps these calls to generate
a kernel oops.

At the moment, the policy for all APIs has not changed. They
still all oops upon a failed check/

The macros now use the Z_ notation for private APIs.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2018-05-17 23:34:03 +03:00
Andrew Boie 97bf001f11 userspace: get dynamic objs from thread rsrc pools
Dynamic kernel objects no longer is hard-coded to use the kernel
heap. Instead, objects will now be drawn from the calling thread's
resource pool.

Since we now have a reference counting mechanism, if an object
loses all its references and it was dynamically allocated, it will
be automatically freed.

A parallel dlist is added for efficient iteration over the set of
all dynamic objects, allowing deletion during iteration.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2018-05-16 17:32:59 -07:00
Andrew Boie e9cfc54d00 kernel: remove k_object_access_revoke() as syscall
Forthcoming patches will dual-purpose an object's permission
bitfield as also reference tracking for kernel objects, used to
handle automatic freeing of resources.

We do not want to allow user thread A to revoke thread B's access
to some object O if B is in the middle of an API call using O.

However we do want to allow threads to revoke their own access to
an object, so introduce a new API and syscall for that.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2018-05-16 17:32:59 -07:00
Andrew Boie 818a96d3af userspace: assign thread IDs at build time
Kernel object metadata had an extra data field added recently to
store bounds for stack objects. Use this data field to assign
IDs to thread objects at build time. This has numerous advantages:

* Threads can be granted permissions on kernel objects before the
  thread is initialized. Previously, it was necessary to call
  k_thread_create() with a K_FOREVER delay, assign permissions, then
  start the thread. Permissions are still completely cleared when
  a thread exits.

* No need for runtime logic to manage thread IDs

* Build error if CONFIG_MAX_THREAD_BYTES is set too low

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2017-11-03 11:29:23 -07:00
Andrew Boie a2b40ecfaf userspace handlers: finer control of init state
We also need macros to assert that an object must be in an
uninitialized state. This will be used for validating thread
and stack objects to k_thread_create(), which must not be already
in use.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2017-10-16 19:02:00 -07:00
Andrew Boie 41bab6e360 userspace: restrict k_object_access_all_grant()
This is too powerful for user mode, the other access APIs
require explicit permissions on the threads that are being
granted access.

The API is no longer exposed as a system call and hence will
only be usable by supervisor threads.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2017-10-16 16:16:28 -07:00
Andrew Boie 04caa679c9 userspace: allow thread IDs to be re-used
It's currently too easy to run out of thread IDs as they
are never re-used on thread exit.

Now the kernel maintains a bitfield of in-use thread IDs,
updated on thread creation and termination. When a thread
exits, the permission bitfield for all kernel objects is
updated to revoke access for that retired thread ID, so that
a new thread re-using that ID will not gain access to objects
that it should not have.

Because of these runtime updates, setting the permission
bitmap for an object to all ones for a "public" object doesn't
work properly any more; a flag is now set for this instead.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2017-10-16 16:16:28 -07:00
Leandro Pereira 6f99bdb02a kernel: Provide only one _SYSCALL_HANDLER() macro
Use some preprocessor trickery to automatically deduce the amount of
arguments for the various _SYSCALL_HANDLERn() macros.  Makes the grunt
work of converting a bunch of kernel APIs to system calls slightly
easier.

Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
2017-10-16 13:42:15 -04:00
Andrew Boie a89bf01192 kernel: add k_object_access_revoke() system call
Does the opposite of k_object_access_grant(); the provided thread will
lose access to that kernel object.

If invoked from userspace the caller must hace sufficient access
to that object and permission on the thread being revoked access.

Fix documentation for k_object_access_grant() API to reflect that
permission on the thread parameter is needed as well.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2017-10-13 15:08:40 -07:00
Andrew Boie 225e4c0e76 kernel: greatly simplify syscall handlers
We now have macros which should significantly reduce the amount of
boilerplate involved with defining system call handlers.

- Macros which define the proper prototype based on number of arguments
- "SIMPLE" variants which create handlers that don't need anything
  other than object verification

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2017-10-12 16:26:28 -05:00
Andrew Boie 7e3d3d782f kernel: userspace.c code cleanup
- Dumping error messages split from _k_object_validate(), to avoid spam
  in test cases that are expected to have failure result.

- _k_object_find() prototype moved to syscall_handler.h

- Clean up k_object_access() implementation to avoid double object
  lookup and use single validation function

- Added comments, minor whitespace changes

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2017-10-12 16:26:28 -05:00
Andrew Boie 37ff5a9bc5 kernel: system call handler cleanup
Use new _SYSCALL_OBJ/_SYSCALL_OBJ_INIT macros.

Use new _SYSCALL_MEMORY_READ/_SYSCALL_MEMORY_WRITE macros.

Some non-obvious checks changed to use _SYSCALL_VERIFY_MSG.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2017-10-11 17:54:47 -07:00
Andrew Boie 743e4686a0 kernel: add syscalls for k_object_access APIs
These modify kernel object metadata and are intended to be callable from
user threads, need a privilege elevation for these to work.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2017-10-05 12:53:41 -04:00