PT_DETACH ptrace(2) requests from functioning as advertised in the
manual page. As described in kern/35175, the PT_DETACH request will,
under certain circumstances, pass an unwanted signal on to the traced
process upan detaching from it. The PT_CONTINUE request will
sometimes fail if you make it pass a signal that has "properties" that
differ from the properties of the signal that origionally caused the
traced process to be stopped. Since PT_KILL is nothing than
PT_CONTINUE with SIGKILL, it is broken too. In the PT_KILL case, this
leads to an unkillable process.
PR: 44011
Submitted by: Mark Kettenis <kettenis@chello.nl>
Approved by: re(jhb)
on if_fxp cards. When flow control is enabled, if the operating system
doesn't acknowledge the packet buffer filling, the card will begin to
generate ethernet quench packets, but appears to get into a feedback
loop of some sort, hosing local switches. This is a temporary workaround
for 5.1: the ability to configure flow control should probably be
exposed by some or another management interface on ethernet link layer
devices.
Approved by: re (bmah)
Reviewed by: mux
instead of taking the (userland) eflags from the trap frame and masking
out PSL_I. There is no need to inherit any flags from the forking process;
the old method however can cause flags set in userland for the forking
process to be bogusly set in kernel mode when the newly forked process
runs for the first time (in particular PSL_T, which is set for userland
when the process is single-stepped; this would cause trace traps in
kernel mode).
Approved by: re (jhb)
VOP_SETATTR() or VOP_GETATTR(); without these locks (a) VFS_DEBUG_LOCKS
will panic, and (b) it may be possible to corrupt entries in the cached
vnode attributes in the nfsnode, since nfsnode attribute cache data is
also protected by the vnode lock.
Approved by: re (jhb)
Pointed out by: VFS_DEBUG_LOCKS
only while holding appropriate vnode locks. This patch slides the lock
release for ufs_extattr_enable() to continue to hold the active vnode lock
on a backing file until after the flag change; it also acquires a vnode
lock when disabling an attribute and hence clearing a flag on the backing
vnode. This permits VFS_DEBUG_LOCKS to run UFS1 extended attributes
without panicking, as well as preventing a potential race and vnode flag
problem.
Approved by: re (jhb)
Pointed out by: DEBUG_VFS_LOCKS
netstat(1) not display it for now because its effects are not yet
completely implemented and we're about to cut 5.2-RELEASE.
This is temporary.
Approved by: re (scottl, rwatson)
in the case where the bridge node was closed down but a timeout
still applied to it, the final reference to the node was freeing the private
data structure using the wrong malloc type.
Approved by: re@
all of the Optio series have the same problems. It might be a better
approach eventually to add wildcard support to USB quirks.
PR: kern/50271, kern/46369
Approved by: re (rwatson)
- Fix compilation without GEM_DEBUG.
- Do not #define GEM_DEBUG by default; it adds overhead (due to bzero()ing
RX space) and is not needed any more, since the driver is quite stable
now.
- Fix watchdog timeouts when failing to load TX packets.
- Do not forcibly limit the number of descriptors used for a packet to
GEM_NTXSEGS, by passing this number to bus_dma_tag_create(). There is
no requirement for a limit any lower than the total number of
available descriptors, and the present limit caused network problems
due to mbuf chains requiring more descriptors.
GEM_NTXSEGS is still used to estimate the interrupt window size, for
which we just need an estimate.
Approved by: re (rwatson)
The submitter of PR 32118 told me that this patch also fixes autoselecting
for znyx 4 port cards (10baseT, 100baseTX did work already).
PR: 32118
Reviewed by: imp
Approved by: rwatson (re)
The advantage of using register sets is that you don't focus on each
register seperately, but instead instroduce a level of abstraction.
This reduces the chance of errors, and also simplifies the code.
The register sers form the basis of everything register.
The sets in this file are:
struct _special
contains all of the control related registers, such as instruction
pointer and stack pointer. It also contains interrupt specific registers
like the faulting address. The set is roughly split in 3 groups. The
first contains the registers that define a context or thread. This is
the only group that the kernel needs to switch threads. The second group
contains registers needed in addition to the first group needed to switch
userland threads. This group contains the thread pointer and the FP control
register. The third group contains those registers we need for execption
handling and are used on top of the first two groups.
struct _callee_saved, struct _callee_saved_fp
These sets contain the preserved registers, including the NaT after
spilling. The general registers (including branch registers) are
seperated from the FP registers for ptrace(2).
struct _caller_saved, struct _caller_saved_fp
These sets contain the scratch registers based on SDM 2.1, This means that
both ar.csd and ar.ccd are included here, even though they contain ia32
segment register descriptions. We keep seperate NaT bits for scratch and
preserved registers, because they are never saved/restored at the same
time.
struct _high_fp
The upper 96 FP registers that can be enabled/disabled seperately on
the CPU from the lower 32 FP registers. Due to the size of this set,
we treat them specially, even though they are defined as scratch
registers.
CVS ----------------------------------------------------------------------
save and restore "sets" of registers in various places.
The restorectx and swapctx functions are used by cpu_switch()
and deal with the special registers, as well as the preserved
registers.
The *callee_saved* functions are used to save and restore the
preserved registers (integer and floating-point). They are
useful for signal delivery and ptrace support.
The save_high_fp and restore_high_fp functions are used to
"load" and "unload" to and from the CPU as part of lazy context
switching.
The ia32 specific context functions have been kept with the ia32
code.
Approved by: re@ (blanket)
on the epc instruction. The epc instruction, given the permissions
of the page in which the epc is located, allows the privilege level
to be increased with little or no overhead. The previous privilege
level is recorded in the current frame marker and is restored by
a regular (function) return.
Since the epc instruction has to live in a page with non-standard
properties, we hardwire a "gateway" page in the address space. The
address of the gateway page is exported to userland in ar.k7. This
allows us to rewire the page without breaking the ABI.
The syscall stubs in libc are regular function calls that slightly
differ from the normal runtime. The difference is mostly to simplify
the stubs themselves by by moving some of the logic to the kernel.
The libc stubs call into the gateway page (offset 0), from where the
kernel trampolines to the code that sets up a minimal trapframe and
arranges to execute from the kernel stack.
The way back is basicly the same. The kernel returns to the gateway
page, whereby privilege is dropped, and jumps back to the syscall
stub.
Only the special registers are saved in the trapframe. None of the
scratch registers are preserved and since the kernel follows the
same runtime model, none of the preserved registers are saved.
Future enhancements can include the implementation of lightweight
syscalls, where kernel functions are performed without setting up
a trapframe. Good candidates are the *context syscalls for example.
Now that there's a gateway page from which code can be executed in
a non-privileged context, we also have the ideal place to put the
signal trampolines. By moving the signal trampolines from the user
stack to the gateway page, we open up the doors to unexecutable
stacks. The gateway page contains signal trampolines for both the
"legacy" break-based syscall code and the new and improved epc-
based syscall code.
Approved: re@ (blanket)
available by Hewlett-Packard under the MIT license. The unwinder is
small, clean and fast and needed little adaptation for use in the
kernel.
This import has embedded in it the changes needed to make it build
in a kernel environment.
To optimize the common case, the kernel will minimize the number
of registers saved by not saving the preserved registers. In case
access to preserved registers is needed (signal handling, ptrace)
the kernel will unwind to the context of the syscall or exception.
For this we need an unwinder.
Approved by: re (blanket)
load_gs() calls into a single place that is less likely to go wrong.
Eliminate the per-process context switching of MSR_GSBASE, because it
should be constant for a single cpu. Instead, save/restore it during
the loading of the new %gs selector for the new process.
Approved by: re (amd64/* blanket)
has already been registered with ATAPI/CAM (else there is nothing
to do). atapi_cam_reinit_bus may be called before the bus is
registered if an ATAPI command times out during the boot sequence.
PR: i386/51421
Reviewed by: roberto
Approved by: re (rwatson)
MFC after: 1 week
stolen from the ia64/ia32 code (indeed there was a repocopy), but I've
redone the MD parts and added and fixed a few essential syscalls. It
is sufficient to run i386 binaries like /bin/ls, /usr/bin/id (dynamic)
and p4. The ia64 code has not implemented signal delivery, so I had
to do that.
Before you say it, yes, this does need to go in a common place. But
we're in a freeze at the moment and I didn't want to risk breaking ia64.
I will sort this out after the freeze so that the common code is in a
common place.
On the AMD64 side, this required adding segment selector context switch
support and some other support infrastructure. The %fs/%gs etc code
is hairy because loading %gs will clobber the kernel's current MSR_GSBASE
setting. The segment selectors are not used by the kernel, so they're only
changed at context switch time or when changing modes. This still needs
to be optimized.
Approved by: re (amd64/* blanket)
- Move struct sigacts out of the u-area and malloc() it using the
M_SUBPROC malloc bucket.
- Add a small sigacts_*() API for managing sigacts structures: sigacts_alloc(),
sigacts_free(), sigacts_copy(), sigacts_share(), and sigacts_shared().
- Remove the p_sigignore, p_sigacts, and p_sigcatch macros.
- Add a mutex to struct sigacts that protects all the members of the struct.
- Add sigacts locking.
- Remove Giant from nosys(), kill(), killpg(), and kern_sigaction() now
that sigacts is locked.
- Several in-kernel functions such as psignal(), tdsignal(), trapsignal(),
and thread_stopped() are now MP safe.
Reviewed by: arch@
Approved by: re (rwatson)
don't add the current time to it, but leave it as clear so that when the
timer is disabled, the it_value is always clear.
Reviewed by: bde
Approved by: re (rwatson)
desired buffer is found at one of the roots more than 60% of the time.
Thus, checking both roots before performing either splay eliminates
unnecessary splays on the first tree splayed.
Approved by: re (jhb)
we do not have to run so long with interrupts disabled. This involved
creating tf_addr in the trapframe. Reorganize the trap stubs so that
they consistently reserve the stack space and initialize any missing
bits.
Approved by: re (amd64 stuff)
by using a __packed keyword for the fxp_rfa structure. The Intel
guys who designed this structure with unaligned fields deserve
to be shot.
Tested by: kris
Approved by: re@ (jhb)
synchronization primitives from inside DDB is generally a bad idea,
and in this case it frequently results in panics due to DDB commands
being executed from the sio fast interrupt context on a serial
console. Replace the locking with a note that a lack of locking
means that DDB may get see inconsistent views of the mount and vnode
lists, which could also result in a panic. More frequently,
though, this avoids a panic than causes it.
Discussed with ages ago: bde
Approved by: re (scottl)
common code, the non-trivial part is #ifdef'ed and only executes when
loading amd64 kernels. The rest is trivial but needed for the the amd64
case. (Two variables changed from char ** to Elf_Addr).
Approved by: re (amd64 "low-risk" stuff)
