based on a report from Arne Georg Gleditsch about user-space apps
misbehaving after toggling /proc/sys/kernel/vsyscall64, a review
of the code revealed that the "NOP patching" done there is
fundamentally unsafe for a number of reasons:
1) the patching code runs without synchronizing other CPUs
2) it inserts NOPs even if there is no clock source which provides vread
3) when the clock source changes to one without vread we run in
exactly the same problem as in #2
4) if nobody toggles the proc entry from 1 to 0 and to 1 again, then
the syscall is not patched out
as a result it is possible to break user-space via this patching.
The only safe thing for now is to remove the patching.
This code was broken since v2.6.21.
Reported-by: Arne Georg Gleditsch <arne.gleditsch@dolphinics.no>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The KERNEL_TEXT_SIZE constant was mis-named, as we not only map the kernel
text but data, bss and init sections as well.
That name led me on the wrong path with the KERNEL_TEXT_SIZE regression,
because i knew how big of _text_ my images have and i knew about the 40 MB
"text" limit so i wrongly thought to be on the safe side of the 40 MB limit
with my 29 MB of text, while the total image size was slightly above 40 MB.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
recently the 64-bit allyesconfig bzImage kernel started spontaneously
rebooting during early bootup.
after a few fun hours spent with early init debugging, it turns out
that we've got this rather annoying limit on the size of the kernel
image:
#define KERNEL_TEXT_SIZE (40*1024*1024)
which limit my vmlinux just happened to pass:
text data bss dec hex filename
29703744 4222751 8646224 42572719 2899baf vmlinux
40 MB is 42572719 bytes, so my vmlinux was just 1.5% above this limit :-/
So it happily crashed right in head_64.S, which - as we all know - is
the most debuggable code in the whole architecture ;-)
So increase the limit to allow an up to 128MB kernel image to be mapped.
(should anyone be that crazy or lazy)
We have a full 4K of pagetable (level2_kernel_pgt) allocated for these
mappings already, so there's no RAM overhead and the limit was rather
pointless and arbitrary.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
notsc is ignored in 32-bit kernels if CONFIG_X86_TSC is on.. which is
bad, fix it.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix mtrr kernel-doc warning:
Warning(linux-2.6.24-git12//arch/x86/kernel/cpu/mtrr/main.c:677): No description found for parameter 'end_pfn'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The proper way to terminate the e820 chain is with %ebx == 0 on the
last legitimate memory block. However, several BIOSes don't do that
and instead return error (CF = 1) when trying to read off the end of
the list. For this error return, %eax doesn't necessarily return the
SMAP signature -- correctly so, since %ah should contain an error code
in this case.
To deal with some particularly broken BIOSes, we clear the entire e820
chain if the SMAP signature is missing in the middle, indicating a
plain insane e820 implementation. However, we need to make the test
for CF = 1 before the SMAP check.
This fixes at least one HP laptop (nc6400) for which none of the
memory-probing methods (e820, e801, 88) functioned fully according to
spec.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Add comments describing the various NOP sequences.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
P6_NOPs are definitely not supported on some VIA CPUs, and possibly
(unverified) on AMD K7s. It is also the only thing that prevents a
686 kernel from running on Transmeta TM3x00/5x00 (Crusoe) series.
The performance benefit over generic NOPs is very small, so when
building for generic consumption, avoid using them.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The P6 family of NOPs are only available on family >= 6 or above, so
enforce that in the boot code.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We have been promoting Transmeta TM3x00/TM5x00 chips to i686-class
based on the notion that they contain all the user-space visible
features of an i686-class chip. However, this is not actually true:
they lack the EA-taking long NOPs (0F 1F /0). Since this is a
userspace-visible incompatibility, downgrade these CPUs to the
manufacturer-defined i586 level.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Use PF_MEMALLOC to prevent recursive calls in the DBEUG_PAGEALLOC
case. This makes the code simpler and more robust against allocation
failures.
This fixes the following fallback to non-mmconfig:
http://lkml.org/lkml/2008/2/20/551http://bugzilla.kernel.org/show_bug.cgi?id=10083
Also, for DEBUG_PAGEALLOC=n reduce the pool size to one page.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Hi all,
Beginning from commits close to v2.6.25-rc2, running lguest always oopses
the host kernel. Oops is at [1].
Bisection led to the following commit:
commit 37cc8d7f96
x86/early_ioremap: don't assume we're using swapper_pg_dir
At the early stages of boot, before the kernel pagetable has been
fully initialized, a Xen kernel will still be running off the
Xen-provided pagetables rather than swapper_pg_dir[]. Therefore,
readback cr3 to determine the base of the pagetable rather than
assuming swapper_pg_dir[].
static inline pmd_t * __init early_ioremap_pmd(unsigned long addr)
{
- pgd_t *pgd = &swapper_pg_dir[pgd_index(addr)];
+ /* Don't assume we're using swapper_pg_dir at this point */
+ pgd_t *base = __va(read_cr3());
+ pgd_t *pgd = &base[pgd_index(addr)];
pud_t *pud = pud_offset(pgd, addr);
pmd_t *pmd = pmd_offset(pud, addr);
Trying to analyze the problem, it seems on the guest side of lguest,
%cr3 has a different value from &swapper_pg-dir (which
is AFAIK fine on a pravirt guest):
Putting some debugging messages in early_ioremap_pmd:
/* Appears 3 times */
[ 0.000000] ***************************
[ 0.000000] __va(%cr3) = c0000000, &swapper_pg_dir = c02cc000
[ 0.000000] ***************************
After 8 hours of debugging and staring on lguest code, I noticed something
strange in paravirt_ops->set_pmd hypercall invocation:
static void lguest_set_pmd(pmd_t *pmdp, pmd_t pmdval)
{
*pmdp = pmdval;
lazy_hcall(LHCALL_SET_PMD, __pa(pmdp)&PAGE_MASK,
(__pa(pmdp)&(PAGE_SIZE-1))/4, 0);
}
The first hcall parameter is global pgdir which looks fine. The second
parameter is the pmd index in the pgdir which is suspectful.
AFAIK, calculating the index of pmd does not need a divisoin over four.
Removing the division made lguest work fine again . Patch is at [2].
I am not sure why the division over four existed in the first place. It
seems bogus, maybe the Xen patch just made the problem appear ?
[2]: The patch:
[PATCH] lguest: fix pgdir pmd index cacluation
Remove an error in index calculation which leads to removing
a not existing shadow page table (leading to a Null dereference).
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Added a declaration to asm-x86/lguest.h and moved the extern arrays there
as well. As an alternative to including asm/lguest.h directly, an
include could be put in linux/lguest.h
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: "rusty@rustcorp.com.au" <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This header is needed on other architectures as well (namely h8300),
which currently fails to build without this in place. Rather than
duplicating the port definition completely there, just move this to a
common location instead.
This should get h8300 working again for 2.6.25, in addition to the
changes already pushed by Sato-san in -rc2.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Commit e036eaa681 broke dreamcast pci, this
patch fixes that by reverting the dreamcast specific bits.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Acked-by: Adrian McMenamin <adrian@mcmen.demon.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
The maple bus driver that went into the kernel mainline in September 2007
contained some bugs which were revealed by the update of the kobj code
for the current release series. Unfortunately those bugs also helped
ensure maple devices were properly detected. This patch (against the
current git) now ensures that devices are properly detected again.
(A previous attempt to fix this by delaying initialisation only partially
fixed this - as became apparent when the bus was fully loaded)
Signed-off-by: Adrian McMenamin <adrian@mcmen.demon.co.uk>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Fix the RTC resources setup for sh770x. Whit these proper
start values RTC driver (drivers/rtc/rtc-sh.c) works.
Signed-off-by: Rafael Ignacio Zurita <rizurita@yahoo.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
The C99 specification states in section 6.11.5:
The placement of a storage-class specifier other than at the
beginning of the declaration specifiers in a declaration is an
obsolescent feature.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Remove an unused variable from the definition of struct maple_device
Signed-off-by: Adrian McMenamin <adrian@mcmen.demon.co.uk>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Fix an off-by-one spotted by the Coverity checker.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Glenn Streiff <gstreiff@neteffect.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Adrian Bunk pointed out that a Coverity scan found some apparently
dead code in nes_verbs.c that really shouldn't have been dead.
The function nes_create_cq() was missing the assignment
err = 1;
just prior to an iteration that conditionally set err = 0 if a PBL was
found for a given virtual CQ. I also noticed we should have been
returning -EFAULT on a couple related error paths.
Signed-off-by: Chien Tung <ctung@neteffect.com>
Signed-off-by: Glenn Streiff <gstreiff@neteffect.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
A single entry (addr 0x10001000, size 0x2000) will get converted to
page address 0x10000000 with a page size of 0x4000. The code as it
stands doesn't address the single buffer case, but in fact it allows
the subsequent single-buffer special case to be eliminated entirely.
Because the mask now includes the (page adjusted) starting and ending
addresses, the general case works for the single buffer case as well.
Signed-off-by: Bryan Rosenburg <rosnbrg@us.ibm.com>
Acked-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Add each lock class to the all_lock_classes list when it is
first registered.
Previously, lock classes were added to all_lock_classes when
the lock class was first used. Since one of the uses of the
list is to find unused locks, this didn't work well.
Signed-off-by: Dale Farnsworth <dale@farnsworth.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Some code paths exceed the current max lock depth (XFS), so increase
this limit a bit. I looked at making this a dynamic allocated array,
but we should not advocate insane lock depths, so stay with this as
long as it works...
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add missing ext4_journal_stop() in error handling.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: adilger@clusterfs.com
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mingming Cao <cmm@us.ibm.com>
Change getting task_struct by get_proc_task() at read or write time,
and returns -ESRCH if get_proc_task() returns NULL.
This is same behavior as other /proc files.
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
At lstats_open(), calling get_proc_task() gets task struct, but it never put.
put_task_struct() should be called when releasing.
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reading /proc/<pid>/latency or /proc/<pid>/task/<tid>/latency could cause
NULL pointer dereference.
In lstats_open(), get_proc_task() can return NULL, in which case the kernel
will oops at lstats_show_proc() because m->private is NULL.
When get_proc_task() returns NULL, the kernel should return -ENOENT.
This can be reproduced by the following script.
while :
do
date
bash -c 'ls > ls.$$' &
pid=$!
cat /proc/$pid/latency &
cat /proc/$pid/latency &
cat /proc/$pid/latency &
cat /proc/$pid/latency
done
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Avoids sparse warnings:
kernel/sched.c:2170:17: warning: symbol 'schedule_tail' was not declared. Should it be static?
Avoids the need for an external declaration in arch/um/process.c
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Unsigned long values are always assigned to switch_count,
make it unsigned long.
kernel/sched.c:3897:15: warning: incorrect type in assignment (different signedness)
kernel/sched.c:3897:15: expected long *switch_count
kernel/sched.c:3897:15: got unsigned long *<noident>
kernel/sched.c:3921:16: warning: incorrect type in assignment (different signedness)
kernel/sched.c:3921:16: expected long *switch_count
kernel/sched.c:3921:16: got unsigned long *<noident>
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
pick_task_entity() duplicates existing code. This functionality can be
easily obtained using rb_last(). Avoid code duplication by using rb_last().
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
do not call sched_clock() too early. Not only might rq->idle
not be set up - but pure per-cpu data might not be accessible
either.
this solves an ia64 early bootup hang with CONFIG_PRINTK_TIME=y.
Tested-by: Tony Luck <tony.luck@gmail.com>
Acked-by: Tony Luck <tony.luck@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Without this, it's possible to have CONFIG_SUPERH32=y set on SH5-103
parts, which leads to much build badness.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
drivers/char/pcmcia/synclink_cs.c:284:1: warning: "CCR3" redefined
In file included from include/asm/cache.h:13,
from include/asm/processor_32.h:15,
from include/asm/processor.h:60,
from include/linux/prefetch.h:14,
from include/linux/list.h:8,
from include/linux/module.h:9,
from drivers/char/pcmcia/synclink_cs.c:38:
include/asm/cpu/cache.h:38:1: warning: this is the location of the previous definition
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Fix following warnings:
WARNING: vmlinux.o(.text+0x4f980): Section mismatch in reference from the function kernel_map_range() to the function .init.text:__alloc_bootmem()
WARNING: vmlinux.o(.text+0x4f9cc): Section mismatch in reference from the function kernel_map_range() to the function .init.text:__alloc_bootmem()
alloc_bootmem() is only used during early init and for any subsequent
call to kernel_map_range() the program logic avoid the call.
So annotate kernel_map_range() with __ref to tell modpost to
ignore the reference to a __init function.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix following warnings:
WARNING: vmlinux.o(.text+0x4b258): Section mismatch in reference from the function dr_cpu_data() to the function .devinit.text:mdesc_fill_in_cpu_data()
WARNING: vmlinux.o(.text+0x4b290): Section mismatch in reference from the function dr_cpu_data() to the function .cpuinit.text:cpu_up()
mdesc_fill_in_cpu_data() is only used during early init and for
cpu hotplug so the __cpuinit annotation is the correct choice.
We have the call chain:
dr_cpu_data() => dr_cpu_configure() => mdesc_fill_in_cpu_data()
dr_cpu_data() is used only during early init and for cpu
hotplug. So annotating them all __cpuinit solves the
section mismatch and should be correct.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
CC [M] arch/sparc/kernel/led.o
arch/sparc/kernel/led.c: In function 'led_blink':
arch/sparc/kernel/led.c:35: error: invalid use of undefined type 'struct
timer_list'
arch/sparc/kernel/led.c:35: error: 'jiffies' undeclared (first use in
this function)
arch/sparc/kernel/led.c:35: error: (Each undeclared identifier is
reported only once
arch/sparc/kernel/led.c:35: error: for each function it appears in.)
arch/sparc/kernel/led.c:36: error: 'avenrun' undeclared (first use in
this function)
arch/sparc/kernel/led.c:36: error: 'FSHIFT' undeclared (first use in
this function)
arch/sparc/kernel/led.c:36: error: 'HZ' undeclared (first use in this
function)
arch/sparc/kernel/led.c:37: error: invalid use of undefined type 'struct
timer_list'
arch/sparc/kernel/led.c:39: error: invalid use of undefined type 'struct
timer_list'
arch/sparc/kernel/led.c:40: error: invalid use of undefined type 'struct
timer_list'
arch/sparc/kernel/led.c:42: error: implicit declaration of function
'add_timer'
arch/sparc/kernel/led.c: In function 'led_write_proc':
arch/sparc/kernel/led.c:70: error: implicit declaration of function
'copy_from_user'
arch/sparc/kernel/led.c:84: error: implicit declaration of function
'del_timer_sync'
arch/sparc/kernel/led.c: In function 'led_init':
arch/sparc/kernel/led.c:109: error: implicit declaration of function
'init_timer'
arch/sparc/kernel/led.c:110: error: invalid use of undefined type
'struct timer_list'
make[1]: *** [arch/sparc/kernel/led.o] Error 1
Based upon original patch by Robert Reif.
Signed-off-by: David S. Miller <davem@davemloft.net>
Thomas Gleixner
Ingo Molnar
Yinghai Lu
Pavel Machek
Randy Dunlap
H. Peter Anvin
Ahmed S. Darwish
Tony Breeds
Harvey Harrison
Lachlan McIlroy
Paul Mundt
Hideo Saito
Magnus Damm
Adrian McMenamin
Rafael Ignacio Zurita
Roel Kluin
Tobias Klauser
Lachlan McIlroy
Adrian Bunk
Chien Tung
Bryan Rosenburg
Jeff Garzik
Dale Farnsworth
Peter Zijlstra
Akinobu Mita
Hiroshi Shimamoto
Balbir Singh
Sonic Zhang
Sam Ravnborg
David S. Miller