The SIGTRAP signal is thrown from the kernel if EVENT_MASK (ptrace_event)
enables PTRACE_FORK. This new si_code helps debuggers to distinguish the
exact source of signal delivered for a debugger.
Another purpose of TRAP_CHLD is to retain the same behavior inside the
NetBSD kernel for process child traps and have an interface to monitor it.
Retrieving exact event and extended properties of process child trap is
available with PT_GET_PROCESS_STATE.
There is no behavior change for existing software.
This si_code value is NetBSD extension.
Sponsored by <The NetBSD Foundation>
This removes dead code introduced with the following commit:
date: 2012-07-27 22:52:49 +0200; author: christos; state: Exp; lines: +8 -2;
revert racy vfork() parent-blocking-before-child-execs-or-exits code.
ok rmind
This interface is designed to read signal information emited to tracee and
fake this signal with new value.
This functionality is required to distinguish types of events that occured
in the tracee and intercepted by a debugger.
These accessors introduce a new structure type ptrace_siginfo:
/*
* Signal Information structure
*/
typedef struct ptrace_siginfo {
siginfo_t psi_siginfo; /* signal information structure */
lwpid_t psi_lwpid; /* destination LWP of the signal
* value 0 means the whole process
* (route signal to all LWPs) */
} ptrace_siginfo_t;
Include <sys/siginfo.h> in <sys/ptrace.h> in order to not break existing
software due to unknown symbol siginfo_t.
This interface has been proposed to the tech-kern@ mailing list.
Sponsored by <The NetBSD Foundation>
On exec() events under a debugger generate the SIGTRAP signal with
TRAP_EXEC property. This allows tracer to distinguish exec() events easily.
Sponsored by <The NetBSD Foundation>
its timestamps.
As this changes storage structures for data passed between kernel and
userland, welcome to 7.99.55!
XXX Output routines still use microsecond resolution when printf()ing.
XXX Possible future feature would be addition of option to use
XXX getbintime(9) for less time-critical histories.
Increment v_holdcnt to prevent the vnode from disappearing while
vcache_vget() waits for a stable state.
Now v_usecount tracks the number of successfull references.
up using the old key until vcache_rekey_exit changes the key to the new one.
Add an assertion that the temporary key is different from the current one.
for averages. Otherwise the decisions can be heavily biased by rounding
errors.
Add sysctl kern.sched_average_weight to change the weight of
historical data, the default is 50%.
to lock this vnodes v_interlock -> vdrain_lock another vnode sharing the
v_interlock may lock this order.
While here, restore fstrans_start_nowait arg to FSTRANS_LAZY.
Fixes a deadlock seen recently on some pbulk environments.
Add new ptrace(2) calls:
- PT_COUNT_WATCHPOINTS - count the number of available hardware watchpoints
- PT_READ_WATCHPOINT - read struct ptrace_watchpoint from the kernel state
- PT_WRITE_WATCHPOINT - write new struct ptrace_watchpoint state, this
includes enabling and disabling watchpoints
The ptrace_watchpoint structure contains MI and MD parts:
typedef struct ptrace_watchpoint {
int pw_index; /* HW Watchpoint ID (count from 0) */
lwpid_t pw_lwpid; /* LWP described */
struct mdpw pw_md; /* MD fields */
} ptrace_watchpoint_t;
For example amd64 defines MD as follows:
struct mdpw {
void *md_address;
int md_condition;
int md_length;
};
These calls are protected with the __HAVE_PTRACE_WATCHPOINTS guard.
Tested on amd64, initial support added for i386 and XEN.
Sponsored by <The NetBSD Foundation>
of the lists. Speeds up namei on cached vnodes by ~3 percent.
Merge "vrele_thread" into "vdrain_thread" so we have one thread
working on the lrulists. Adapt vfs_drainvnodes() to always wait
for a complete cycle of vdrain_thread().
always equal to "desiredvnodes" and move its definition
from sys/vnode.h to sys/vnode_impl.h.
Extend vfs_drainvnodes() to also wait for deferred vrele to flush
and replace the call to vrele_flush() with a call to vfs_drainvnodes().
This allows us to return EEXIST instead of EPERM for higher secure levels.
My use case was to stop npfctl complaining that it could not load bpfjit
on ERLITE when it was compiled into the kernel.
It then went on to complain that NPF performance would be de-graded,
but this is clearly not the case.
When called from vrecycle() or vgone() there is a window where the refcount
is greater than zero and another thread could get and release a reference
that would miss VOP_INACTIVE() as the refcount doesn't drop to zero.
Adjust test fs/puffs/t_basic: test VOP_INACTIVE count being greater zero.
- Make vrecycle() more robust by checking v_usecount first and preventing
further references across vn_lock(). Fixes a deadlock where one thread
starts unmount, second thread locks a directory and allocates a vnode
and first thread tries to vrecycle() the directory.
First thread holds vfs_busy and wants vnode, second thread holds vnode
and wants vfs_busy.
- With these fixes in place change cleanvnode() to use vget()/vrecycle()
to reclaim the vnode.
xc_lowpri and xc_thread are racy and xc_wait may return during/before
executing all xcall callbacks, resulting in a kernel panic at worst.
xc_lowpri serializes multiple jobs by a mutex and a cv. If all xcall
callbacks are done, xc_wait returns and also xc_lowpri accepts a next job.
The problem is that a counter that counts the number of finished xcall
callbacks is incremented *before* actually executing a xcall callback
(see xc_tailp++ in xc_thread). So xc_lowpri accepts a next job before
all xcall callbacks complete and a next job begins to run its xcall callbacks.
Even worse the counter is global and shared between jobs, so if a xcall
callback of the next job completes, the shared counter is incremented,
which confuses wc_wait of the previous job as all xcall callbacks of the
previous job are done and wc_wait of the previous job returns during/before
executing its xcall callbacks.
How to fix: there are actually two counters that count the number of finished
xcall callbacks for low priority xcall for historical reasons (I guess):
xc_tailp and xc_low_pri.xc_donep. xc_low_pri.xc_donep is incremented correctly
while xc_tailp is incremented wrongly, i.e., before executing a xcall callback.
We can fix the issue by dropping xc_tailp and using only xc_low_pri.xc_donep.
PR kern/51632
