When a process is exiting, there is a narrow window where p_cred may be
NULL while its threads are still executing. Specifically, the last thread
to exit a process sets the process state to PRS_ZOMBIE with the proc
spinlock held and then calls thread_exit(). thread_exit() drops the spin
lock, permitting the process to be reaped and thus causing its cred struct
to be released. However, the exiting thread may still cause DTrace probes
to fire by calling sched_throw(), resulting in a double fault if such a
probe enabling attempts to access the GID or UID DIF variables.
The thread's cred reference is not susceptible to this race since it is not
released until after the thread has exited.
MFC after: 1 week
This field is only used in a KASSERT that verifies that no locks are held
when returning to user mode. Moreover, the td_locks accounting is only
correct when LOCK_DEBUG > 0, which is implied by INVARIANTS.
Reviewed by: jhb
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D3205
Some of FDT blobs for AM335x-based devices use pinmux pullup/pulldown
flag to setup initial GPIO ouputp value, e.g. 4DCAPE-43 sets LCD DATAEN
signal this way. It works for Linux because Linux driver does not enforce
pin direction until after it's requested by consumer. So input with pullup
flag set acts as output with GPIO_HIGH value
Reviewed by: loos
I also changed ${...%*/rc.d} to ${...%/rc.d} since the shortest match always
has an empty string for the asterisk.
PR: 201641
Submitted by: Jamie Landeg-Jones (original version)
MFC after: 1 week
original parent. Otherwise the debugee will be set as an orphan of
the debugger.
Add tests for tracing forks via PT_FOLLOW_FORK.
Reviewed by: kib
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D2809
Summary:
Use the newly created `kern_shm_open()` function to create objects with
just the rights that are actually needed.
Reviewers: jhb, kib
Subscribers: imp
Differential Revision: https://reviews.freebsd.org/D3260
This allows you to specify the capabilities that the new file descriptor
should have. This allows us to create shared memory objects that only
have the rights we're interested in.
The idea behind restricting the rights is that it makes it a lot easier
for CloudABI to get consistent behaviour across different operating
systems. We only need to make sure that a shared memory implementation
consistently implements the operations that are whitelisted.
Approved by: kib
Obtained from: https://github.com/NuxiNL/freebsd
Revert r286102 and apply a cleaner fix.
Tested for overflows by FORTIFY_SOURCE GSoC (with clang).
Suggested by: bde
Reviewed by: Oliver Pinter
Tested by: Oliver Pinter
MFC after: 3 days
The first one never triggers because bpf_canfreebuf() can only be true for
zero-copy buffers and zero-copy buffers are not read with read(2).
The second also never triggers, because we check the free buffer before
calling ROTATE_BUFFERS(). If the hold buffer is in use the free buffer
will be NULL and there is nothing else to do besides drop the packet. If
the free buffer isn't NULL the hold buffer _is_ free and it is safe to
rotate the buffers.
Update the comment in ROTATE_BUFFERS macro to match the logic described
here.
While here fix a few typos in comments.
MFC after: 2 weeks
Sponsored by: Rubicon Communications (Netgate)
The buffer must be allocated (or even changed) before the interface is set
and thus, there is no need to verify if the buffer is in use.
MFC after: 2 weeks
Sponsored by: Rubicon Communications (Netgate)
the buffer is allocated we are committed to a particular buffer method
(BPF_BUFMODE_BUFFER in this case).
If we are using zero-copy buffers, the userland program must register its
buffers before set the interface.
If we are using kernel memory buffers, we can allocate the buffer at the
time that the interface is being set.
This fix allows the usage of BIOCSETBUFMODE after r235746.
Update the comments to reflect the recent changes.
MFC after: 2 weeks
Sponsored by: Rubicon Communications (Netgate)
unwind_frame function to read each stack frame until either the pc or stack
are no longer withing the kernel's address space.
Obtained from: ABT Systems Ltd
Sponsored by: The FreeBSD Foundation
This is copied from the amd64 version with minor changes. These should be
merged into a single file as from a quick look there are other copies of
the same file in other parts of the tree.
Obtained from: ABT Systems Ltd
Sponsored by: The FreeBSD Foundation
when trying to read data from outside the DMAP region. I expect this panic
to be from within uiomove_fromphys, which needs to grow support to support
such addresses.
Obtained from: ABT Systems Ltd
Sponsored by: The FreeBSD Foundation
On CloudABI, the rights bits returned by cap_rights_get() match up with
the operations that you can actually perform on the file descriptor.
Limiting the rights is good, because it makes it easier to get uniform
behaviour across different operating systems. If process descriptors on
FreeBSD would suddenly gain support for any new file operation, this
wouldn't become exposed to CloudABI processes without first extending
the rights.
Extend fork1() to gain a 'struct filecaps' argument that allows you to
construct process descriptors with custom rights. Use this in
cloudabi_sys_proc_fork() to limit the rights to just fstat() and
pdwait().
Obtained from: https://github.com/NuxiNL/freebsd
still on going, but it has passed world for mips and powerpc...
I know this has an extra semicolon, but this is the patch that is
tested...
Looks like better fix is to use _Static_assert...
has observable overhead when the buffer pages are not resident or not
mapped. The overhead comes at least from two factors, one is the
additional work needed to detect the situation, prepare and execute
the rollbacks. Another is the consequence of the i/o splitting into
the batches of the held pages, causing filesystems see series of the
smaller i/o requests instead of the single large request.
Note that expected case of the resident i/o buffer does not expose
these issues. Provide a prefaulting for the userspace i/o buffers,
disabled by default. I am careful of not enabling prefaulting by
default for now, since it would be detrimental for the applications
which speculatively pass extra-large buffers of anonymous memory to
not deal with buffer sizing (if such apps exist).
Found and tested by: bde, emaste
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
