The PT_I386_{GET,SET}XMMREGS and PT_{GET,SET}XSTATE operate on the
stopped threads. Implementation assumes that the thread's FPU context
is spilled into the PCB due to stop. This is mostly true, except when
FPU state for the thread is not initialized. Then the requests operate
on the garbage state which is currently left in the PCB, causing
confusion.
The situation is indeed observed after a signal delivery and before
#NM fault on execution of any FPU instruction in the signal handler,
since sendsig(9) drops FPU state for current thread, clearing
PCB_FPUINITDONE. When inspecting context state for the signal handler,
debugger sees the FPU state of the main program context instead of the
clear state supposed to be provided to handler.
Fix this by forcing clean FPU state in PCB user FPU save area by
performing getfpuregs(9) before accessing user FPU save area in
ptrace_machdep.c.
Note: this change will be merged to i386 kernel as well, where it is
much more important, since e.g. gdb on i386 uses PT_I386_GETXMMREGS to
inspect FPU context on CPUs that support SSE. Amd64 version of gdb
uses PT_GETFPREGS to inspect both 64 and 32 bit processes, which does
not exhibit the bug.
Stop clearing x87 exceptions in the #MF handler on amd64. If user code
understands FPU hardware enough to catch SIGFPE and unmask exceptions
in control word, then it may as well properly handle return from
SIGFPE without causing an infinite loop of #MF exceptions due to
faulting instruction restart, when needed.
Clearing exceptions causes information loss for handlers which do
understand FPU hardware, and struct siginfo si_code member cannot be
considered adequate replacement for en_sw content due to translation.
Supposed reason for clearing the exceptions, which is IRQ13 handling
oddities, were never applicable to amd64.
Note: this change will be merged to i386 kernel as well, since we do
not support IRQ13 delivery of #MF notifications for some time.
(Incomplete) fixes for symbols visibility issues and style in fcntl.h.
Append '__' prefix to the tag of struct oflock, and put it under BSD
namespace. Structure is needed both by libc and kernel, thus cannot be
hidden under #ifdef _KERNEL.
Move a set of non-standard F_* and O_* constants into BSD namespace.
SUSv4 explicitely allows implemenation to pollute F_* and O_* names
after fcntl.h is included, but it costs us nothing to adhere
to the specification if exact POSIX compliance level is requested by
user code.
Change some spaces after #define to tabs.
Noted by and discussed with: bde
MFC after: 1 week
adrian [Fri, 20 Jul 2012 01:36:02 +0000 (01:36 +0000)]
Add a per-node rate control routine for each rate control module.
For now, the only module implement is 'sample', and that's only partially
implemented. The main issue here with reusing this structure in userland
is that it uses 'rix' everywhere, which requires the userland code to
have access to the current HAL rate table.
For now, this is a very large work in progress.
Specific details:
* The rate control information is per-node at the moment and wrapped
in a TLV, to ease parsing and backwards compatibility.
* .. but so I can be slack for now, the userland statistics are just
a copy of the kernel-land sample node state.
* However, for now use a temporary copy and change the rix entries
to dot11rate entries to make it slightly easier to eyeball.
Problems:
* The actual rate information table is unfortunately indexed by rix
and it doesn't contain a rate code. So the userland side of this
currently has no way to extract out a mapping.
TODO:
* Add a TLV payload to dump out the rate control table mapping so
'rix' can be turned into a dot11 / MCS rate.
* .. then remove the temporary copy.
Introduce curpcb magic variable, similar to curthread, which is MD
amd64. It is implemented as __pure2 inline with non-volatile asm read
from pcpu, which allows a compiler to cache its results.
Convert most PCPU_GET(pcb) and curthread->td_pcb accesses into curpcb.
Note that __curthread() uses magic value 0 as an offsetof(struct pcpu,
pc_curthread). It seems to be done this way due to machine/pcpu.h
needs to be processed before sys/pcpu.h, because machine/pcpu.h
contributes machine-depended fields to the struct pcpu definition. As
result, machine/pcpu.h cannot use struct pcpu yet.
The __curpcb() also uses a magic constant instead of offsetof(struct
pcpu, pc_curpcb) for the same reason. The constants are now defined as
symbols and CTASSERTs are added to ensure that future KBI changes do
not break the code.
marius [Thu, 19 Jul 2012 14:43:46 +0000 (14:43 +0000)]
Revert the use of BUS_DMA_ALLOCNOW when creating the DMA tag for user
data introduced in r236061. Using that flag doesn't make that much
sense on this case as the DMA maps using it are also created during
sym_pci_attach(). Moreover, due to the maxsegsz parameter used, doing
so may exhaust the bounce pages pool on architectures requiring
bounce pages. [1]
While at it, use a slightly more appropriate maxsegsz parameter.
PR: 169526
Submitted by: Mike Watters [1]
MFC after: 3 days
Fix several reads beyond the mapped first page of the binary in the
ELF parser. Specifically, do not allow note reader and interpreter
path comparision in the brandelf code to read past end of the page.
This may happen if specially crafter ELF image is activated.
adrian [Thu, 19 Jul 2012 03:51:16 +0000 (03:51 +0000)]
Convert the TX path to use the new HAL methods for accessing the
TX descriptor link pointers.
This is required for the AR93xx and later chipsets.
The RX path is slightly different - the legacy RX path directly
accesses ath_desc->ds_link for now, however this isn't at all done
for EDMA (FIFO) RX.
Now, for those performing a little software archeology here:
This is all a bit sub-optimal. "struct ath_desc" is only really relevant
for the pre-AR93xx NICs - where ds_link and ds_data is always in the
same location.
The AR93xx and later NICs have different descriptor layouts altogether.
Now, for AR93xx and later NICs, you should never directly reference
ds_link and ds_data, as:
* the RX descriptors don't have either - the data is _after_ the RX
descriptor. They're just one large buffer. There's also no need for
a per-descriptor RX buffer size as they're all fixed sizes.
* the TX descriptors have 4 buffer and 4 length fields _and_ a link
pointer. Each frame takes up one TX FIFO pointer, but it can contain
multiple subframes (either multiple frames in a buffer, and/or
multiple frames in an aggregate/RIFS burst.)
* .. so, when TX frames are queued to a hardware queue, the link
pointer is ONLY for buffers in that frame/aggregate. The next frame
starts in a new FIFO pointer.
* Finally, descriptor completion status is in a different ring.
I'll write something up about that when its time to do so.
This was inspired by Linux ath9k and the reference driver but is a
reimplementation.
On AMD64, provide siginfo.si_code for floating point errors when error
occurs using the SSE math processor. Update comments describing the
handling of the exception status bits in coprocessors control words.
Remove GET_FPU_CW and GET_FPU_SW macros which were used only once.
Prefer to use curpcb to access pcb_save over the longer path of
referencing pcb through the thread structure.
Based on the submission by: Ed Alley <wea llnl gov>
PR: amd64/169927
Reviewed by: bde
MFC after: 3 weeks
ken [Tue, 17 Jul 2012 22:16:10 +0000 (22:16 +0000)]
Add back spare fields consumed in r237545. It seems that these should only
be consumed to maintain backward compatibility in stable, but should not be
consumed in head.
Make sure that arraysz is initialized to a value larger than zero.
arraysz could get initialized to zero on ZFS because ZFS reports
directory sizes differently compared to UFS.
Move unmask IRQ function call up to nexus device level.
FDT-enabled targets were broken after r238043 that relies
on device up the hierarchy to properly setup interrupt.
nexus device for ARM platforms did job only partially:
setting handler but not unmasking interrupt. Unmasking
was performed by platform code.
Various improvements to vm_contig_grow_cache(). Most notably, even when
it can't sleep, it can still move clean pages from the inactive queue to
the cache. Also, when a page is cached, there is no need to restart the
scan. The "next" page pointer held by vm_contig_launder() is still
valid. Finally, add a comment summarizing what vm_contig_grow_cache()
does based upon the value of "tries".
If ip_output() returns EMSGSIZE to tcp_output(), then the latter calls
tcp_mtudisc(), which in its turn may call tcp_output(). Under certain
conditions (must admit they are very special) an infinite recursion can
happen.
To avoid recursion we can pass struct route to ip_output() and obtain
correct mtu. This allows us not to use tcp_mtudisc() but call tcp_mss_update()
directly.
PR: kern/155585
Submitted by: Andrey Zonov <andrey zonov.org> (original version of patch)
Fix a bug with memguard(9) on 32-bit architectures without a
VM_KMEM_MAX_SIZE.
The code was not taking into account the size of the kernel_map, which
the kmem_map is allocated from, so it could produce a sub-map size too
large to fit. The simplest solution is to ignore VM_KMEM_MAX entirely
and base the memguard map's size off the kernel_map's size, since this
is always relevant and always smaller.
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