I've traced down an off-by-one TCP checksum calculation error under
the following conditions:
1) The TCP code needs to split a full-sized packet due to a reduced
MSS (typically due to the addition of TCP options mid-stream like
SACK).
_AND_
2) The checksum of the 2nd fragment is larger than the checksum of the
original packet. After subtraction this results in a checksum for
the 1st fragment with bits 16..31 set to 1. (this is ok)
_AND_
3) The checksum of the 1st fragment's TCP header plus the previously
32bit checksum of the 1st fragment DOES NOT cause a 32bit overflow
when added together. This results in a checksum of the TCP header
plus TCP data that still has the upper 16 bits as 1's.
_THEN_
4) The TCP+data checksum is added to the checksum of the pseudo IP
header with csum_tcpudp_nofold() incorrectly (the bug).
The problem is the checksum of the TCP+data is passed to
csum_tcpudp_nofold() as an 32bit unsigned value, however the assembly
code acts on it as if it is a 64bit unsigned value.
This causes an incorrect 32->64bit extension if the sum has bit 31
set. The resulting checksum is off by one.
This problems is data and TCP header dependent due to #2 and #3
above so it doesn't occur on every TCP packet split.
Signed-off-by: Dave Johnson <djohnson+linux-mips@sw.starentnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
With commit 63dc68a8cf, kernel can not
handle BUG() and BUG_ON() properly since get_user() returns false for
kernel code. Use __get_user() to skip unnecessary access_ok(). This
patch also make BRK_BUG code encoded in the TNE instruction.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The save_fp_context()/restore_fp_context() might sleep on accessing
user stack and therefore might lose FPU ownership in middle of them.
If these function failed due to "in_atomic" test in do_page_fault,
touch the sigcontext area in non-atomic context and retry these
save/restore operation.
This is a replacement of a (broken) fix which was titled "Allow CpU
exception in kernel partially".
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The commit 4d40bff7110e9e1a97ff8c01bdd6350e9867cc10 ("Allow CpU
exception in kernel partially") was broken. The commit was to fix
theoretical problem but broke usual case. Revert it for now.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Recent versions of the BCM112X processors aren't recognized by Linux
(preventing Linux from booting on those processors). This patch adds
support for those that are missing.
Signed-off-by: Mark Mason <mason@broadcom.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
local_irq_restore -> raw_local_irq_restore -> irq_restore_epilog ->
smtc_ipi_replay -> smtc_ipi_dq -> spin_unlock_irqrestore ->
_spin_unlock_irqrestore -> local_irq_restore
The recursion does abort when there is no more IPI queued for a CPU, so
this isn't usually fatal which is why we got away with this for so long
until this was discovered by code inspection.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The missing cast did result a warning when calling an 32-bit ARC firmware
function that takes 5 arguments where the 5th argument is a pointer from a
64-bit kernel.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
In the the sequence:
ei
..
mfc0 $x, $status
the mfc0 may not see the SR_IE bit set. This was a deliberate bug in the
kernel code because we knew this was a safe thing to do on all R2 silicon
so far but new silicon is changing this.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This patch fixes two places where we used plain 'x - PAGE_OFFSET' to
achieve virtual to physical address convertions. This type of convertion
is no more allowed since commit 6f284a2ce7.
Reported-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
[Build fixes for machines that don't use the generic dma-coherence.h]
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This patch removes the static prototypes from the au1xxx_ide.h, some of
them were not even implemented. Also, they caused build breakage since
they differed from the functions actually implemented in
drivers/ide/mips/au1xxx-ide.c.
Signed-off-by: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
include/asm-mips/mach-ip27/dma-coherence.h:22: warning: 'plat_map_dma_mem' defined but not used
include/asm-mips/mach-ip27/dma-coherence.h:41: warning: 'plat_unmap_dma_mem' defined but not used
include/asm-mips/mach-ip32/dma-coherence.h:30: warning: 'plat_map_dma_mem' defined but not used
include/asm-mips/mach-ip32/dma-coherence.h:63: warning: 'plat_unmap_dma_mem' defined but not used
These functions are meant to be inlined anyway.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
o Fix build error.
o Handle error returns.
o Deal with signals received while sleeping.
o Don't allow to be selected when we're not building the directory with
the driver anyway.
o Coding style cleanups.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
A deadlock can occur for mixed irq and non-irq rwlock readers if a 2nd
reader attempts to take lock by looping around __raw_read_trylock().
Signed-off-by: Dave Johnson <djohnson+linux-mips@sw.starentnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Remove the SMT-nice feature which idles sibling cpus on SMT cpus to
facilitiate nice working properly where cpu power is shared. The idling of
cpus in the presence of runnable tasks is considered too fragile, easy to
break with outside code, and the complexity of managing this system if an
architecture comes along with many logical cores sharing cpu power will be
unworkable.
Remove the associated per_cpu_gain variable in sched_domains used only by
this code.
Also:
The reason is that with dynticks enabled, this code breaks without yet
further tweaks so dynticks brought on the rapid demise of this code. So
either we tweak this code or kill it off entirely. It was Ingo's preference
to kill it off. Either way this needs to happen for 2.6.21 since dynticks
has gone in.
Signed-off-by: Con Kolivas <kernel@kolivas.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The generic rtc-ds1742 driver can be used for RBTX4927 and JMR3927
(with __swizzle_addr trick). This patch also removes MIPS local
DS1742 stuff.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Big endian RMs uses a different mc146818_decode_year than little endian RMs
Correct mc146818_decode_year for years before 2000
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Delete the definition of the apparently unreferenced macro _IOC_SLMASK.
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Use MIPS_CPU_IRQ_BASE instead of own define.
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This patch adds trivial support for SMARTMIPS extension. This extension
is currently implemented by 4KS[CD] CPUs.
Basically it saves/restores ACX register, which is part of the SMARTMIPS
ASE, when needed. This patch does *not* add any support for Smartmips MMU
features.
Futhermore this patch does not add explicit support for 4KS[CD] CPUs since
they are respectively mips32 and mips32r2 compliant. So with the current
processor configuration, a platform that has such CPUs needs to select
both configs:
CPU_HAS_SMARTMIPS
SYS_HAS_CPU_MIPS32_R[12]
This is due to the processor configuration which is mixing up all the
architecture variants and the processor types.
The drawback of this, is that we currently pass '-march=mips32' option to
gcc when building a kernel instead of '-march=4ksc' for 4KSC case. This
can lead to a kernel image a little bit bigger than required.
Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
From the 01408c4939 log message:
The problem is that when we write to a file, the copy from userspace to
pagecache is first done with preemption disabled, so if the source
address is not immediately available the copy fails *and* *zeros* *the*
*destination*.
This is a problem because a concurrent read (which admittedly is an odd
thing to do) might see zeros rather that was there before the write, or
what was there after, or some mixture of the two (any of these being a
reasonable thing to see).
If the copy did fail, it will immediately be retried with preemption
re-enabled so any transient problem with accessing the source won't
cause an error.
The first copying does not need to zero any uncopied bytes, and doing
so causes the problem. It uses copy_from_user_atomic rather than
copy_from_user so the simple expedient is to change copy_from_user_atomic
to *not* zero out bytes on failure.
< --- end cite --- >
This patch finally implements at least a not so pretty solution by
duplicating the relevant part of __copy_user.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The kernel use 64-bit for sc_regs[0], and both N32/N64 userland
expects it was 64-bit. But size of 'long' on N32 is actually 32-bit.
So this definition make some confusion. Use __u32 and __u64 for
N32/N64 sigcontext to get rid of this confusion.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This fixes some sparse warnings.
pgtable-32.c:15:6: warning: symbol 'pgd_init' was not declared. Should it be static?
pgtable-32.c:32:13: warning: symbol 'pagetable_init' was not declared. Should it be static?
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Add R2 optimized variants of clear_bit, set_bit and test_and_clear_bit.
With gcc 4.1.1 this saves 1592 bytes on a defconfig (minus IPv6) kernel.
Turns out that R2 bitop instructions are no gain for the other bitop
functions.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This implementation has support for the concept of one separate ioport
address space by PCI domain. A pointer to the virtual address where
the port space of a domain has been mapped has been added to struct
pci_controller and systems should be fixed to fill in this value. For
single domain systems this will be the same value as passed to
set_io_port_base().
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
access_ok in compat-signal.h is wrong (checking destination instead of
source) and redundant (already checked before calling this function).
Also sf_mask in struct sigframe32 should be compat_sigset_t type.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This did result in double clearing of the error return value on success
only but should make a meassurable overhead for sigreturn.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Dave Johnson
Atsushi Nemoto
Mark Mason
Ralf Baechle
Deepak Saxena
Franck Bui-Huu
Daniel Mack
Con Kolivas
Thomas Bogendoerfer
Robert P. J. Day