Peter Feiner [Mon, 13 Oct 2014 22:55:46 +0000 (15:55 -0700)]
mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared
For VMAs that don't want write notifications, PTEs created for read faults
have their write bit set. If the read fault happens after VM_SOFTDIRTY is
cleared, then the PTE's softdirty bit will remain clear after subsequent
writes.
Here's a simple code snippet to demonstrate the bug:
With this patch, write notifications are enabled when VM_SOFTDIRTY is
cleared. Furthermore, to avoid unnecessary faults, write notifications
are disabled when VM_SOFTDIRTY is set.
As a side effect of enabling and disabling write notifications with
care, this patch fixes a bug in mprotect where vm_page_prot bits set by
drivers were zapped on mprotect. An analogous bug was fixed in mmap by
commit c9d0bf241451 ("mm: uncached vma support with writenotify").
kernel/param: consolidate __{start,stop}___param[] in <linux/moduleparam.h>
Consolidate the various external const and non-const declarations of
__start___param[] and __stop___param in <linux/moduleparam.h>. This
requires making a few struct kernel_param pointers in kernel/params.c
const.
Ulrich Obergfell [Mon, 13 Oct 2014 22:55:37 +0000 (15:55 -0700)]
kvm: ensure hard lockup detection is disabled by default
Use watchdog_enable_hardlockup_detector() to set hard lockup detection's
default value to false. It's risky to run this detection in a guest, as
false positives are easy to trigger, especially if the host is
overcommitted.
Ulrich Obergfell [Mon, 13 Oct 2014 22:55:35 +0000 (15:55 -0700)]
kernel/watchdog.c: control hard lockup detection default
In some cases we don't want hard lockup detection enabled by default.
An example is when running as a guest. Introduce
watchdog_enable_hardlockup_detector(bool)
allowing those cases to disable hard lockup detection. This must be
executed early by the boot processor from e.g. smp_prepare_boot_cpu, in
order to allow kernel command line arguments to override it, as well as
to avoid hard lockup detection being enabled before we've had a chance
to indicate that it's unwanted. In summary,
initial boot: default=enabled
smp_prepare_boot_cpu
watchdog_enable_hardlockup_detector(false): default=disabled
cmdline has 'nmi_watchdog=1': default=enabled
The running kernel still has the ability to enable/disable at any time
with /proc/sys/kernel/nmi_watchdog us usual. However even when the
default has been overridden /proc/sys/kernel/nmi_watchdog will initially
show '1'. To truly turn it on one must disable/enable it, i.e.
Andy Shevchenko [Mon, 13 Oct 2014 22:55:27 +0000 (15:55 -0700)]
lib80211: remove unused print_ssid()
In kernel we have %*pE specifier to print an escaped buffer. All users
now switched to that approach.
This fixes a bug as well. The current implementation wrongly prints
octal numbers: only two first digits are used in case when 3 are
required and the rest of the string ends up cut off.
Additionally by default the \f, \v, \a, and \e are escaped to their
alphabetic representation. It's safe to do since it is currently used
for messaging only.
Andy Shevchenko [Mon, 13 Oct 2014 22:55:18 +0000 (15:55 -0700)]
lib/vsprintf: add %*pE[achnops] format specifier
This allows user to print a given buffer as an escaped string. The
rules are applied according to an optional mix of flags provided by
additional format letters.
For example, if the given buffer is:
1b 62 20 5c 43 07 22 90 0d 5d
The result strings would be:
%*pE "\eb \C\a"\220\r]"
%*pEhp "\x1bb \C\x07"\x90\x0d]"
%*pEa "\e\142\040\\\103\a\042\220\r\135"
Please, read Documentation/printk-formats.txt and lib/string_helpers.c
kernel documentation to get further information.
Andy Shevchenko [Mon, 13 Oct 2014 22:55:11 +0000 (15:55 -0700)]
lib / string_helpers: move documentation to c-file
The introduced function string_escape_mem() is a kind of opposite to
string_unescape. We have several users of such functionality each of
them created custom implementation. The series contains clean up of
test suite, adding new call, and switching few users to use it via %*pE
specifier.
Test suite covers all of existing and most of potential use cases.
This patch (of 11):
The documentation of API belongs to c-file. This patch moves it
accordingly.
Xishi Qiu [Mon, 13 Oct 2014 22:55:07 +0000 (15:55 -0700)]
arch/x86/mm/numa.c: fix boot failure when all nodes are hotpluggable
If all the nodes are marked hotpluggable, alloc node data will fail.
Because __next_mem_range_rev() will skip the hotpluggable memory
regions. numa_clear_kernel_node_hotplug() is called after alloc node
data.
numa_init()
...
ret = init_func(); // this will mark hotpluggable flag from SRAT
...
memblock_set_bottom_up(false);
...
ret = numa_register_memblks(&numa_meminfo); // this will alloc node data(pglist_data)
...
numa_clear_kernel_node_hotplug(); // in case all the nodes are hotpluggable
...
This patch moves numa_clear_kernel_node_hotplug() into
numa_register_memblks(), clear kernel node hotpluggable flag before
alloc node data, then alloc node data won't fail even all the nodes
are hotpluggable.
Zach Brown [Mon, 13 Oct 2014 22:55:05 +0000 (15:55 -0700)]
fs: check bh blocknr earlier when searching lru
It's very common for the buffer heads in the lru to have different block
numbers. By comparing the blocknr before the bdev and size we can
reduce the cost of searching in the very common case where all the
entries have the same bdev and size.
In quick hot cache cycle counting tests on a single fs workstation this
cut the cost of a miss by about 20%.
A diff of the disassembly shows the reordering of the bdev and blocknr
comparisons. This is in such a tiny loop that skipping one comparison
is a meaningful portion of the total work being done:
Rasmus Villemoes [Mon, 13 Oct 2014 22:55:03 +0000 (15:55 -0700)]
kdb: replace strnicmp with strncasecmp
The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics and
a slightly buggy strncasecmp. The latter is the POSIX name, so strnicmp
was renamed to strncasecmp, and strnicmp made into a wrapper for the new
strncasecmp to avoid breaking existing users.
To allow the compat wrapper strnicmp to be removed at some point in the
future, and to avoid the extra indirection cost, do
s/strnicmp/strncasecmp/g.
Rasmus Villemoes [Mon, 13 Oct 2014 22:55:01 +0000 (15:55 -0700)]
thermal: replace strnicmp with strncasecmp
The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics and
a slightly buggy strncasecmp. The latter is the POSIX name, so strnicmp
was renamed to strncasecmp, and strnicmp made into a wrapper for the new
strncasecmp to avoid breaking existing users.
To allow the compat wrapper strnicmp to be removed at some point in the
future, and to avoid the extra indirection cost, do
s/strnicmp/strncasecmp/g.
Rasmus Villemoes [Mon, 13 Oct 2014 22:54:59 +0000 (15:54 -0700)]
staging: r8188eu: replace strnicmp with strncasecmp
The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics and
a slightly buggy strncasecmp. The latter is the POSIX name, so strnicmp
was renamed to strncasecmp, and strnicmp made into a wrapper for the new
strncasecmp to avoid breaking existing users.
To allow the compat wrapper strnicmp to be removed at some point in the
future, and to avoid the extra indirection cost, do
s/strnicmp/strncasecmp/g.
Rasmus Villemoes [Mon, 13 Oct 2014 22:54:57 +0000 (15:54 -0700)]
s390/cio: replace strnicmp with strncasecmp
The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics and
a slightly buggy strncasecmp. The latter is the POSIX name, so strnicmp
was renamed to strncasecmp, and strnicmp made into a wrapper for the new
strncasecmp to avoid breaking existing users.
To allow the compat wrapper strnicmp to be removed at some point in the
future, and to avoid the extra indirection cost, do
s/strnicmp/strncasecmp/g.
Rasmus Villemoes [Mon, 13 Oct 2014 22:54:54 +0000 (15:54 -0700)]
PNP: replace strnicmp with strncasecmp
The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics and
a slightly buggy strncasecmp. The latter is the POSIX name, so strnicmp
was renamed to strncasecmp, and strnicmp made into a wrapper for the new
strncasecmp to avoid breaking existing users.
To allow the compat wrapper strnicmp to be removed at some point in the
future, and to avoid the extra indirection cost, do
s/strnicmp/strncasecmp/g.
Rasmus Villemoes [Mon, 13 Oct 2014 22:54:52 +0000 (15:54 -0700)]
thinkpad_acpi: replace strnicmp with strncasecmp
The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics and
a slightly buggy strncasecmp. The latter is the POSIX name, so strnicmp
was renamed to strncasecmp, and strnicmp made into a wrapper for the new
strncasecmp to avoid breaking existing users.
To allow the compat wrapper strnicmp to be removed at some point in the
future, and to avoid the extra indirection cost, do
s/strnicmp/strncasecmp/g.
Rasmus Villemoes [Mon, 13 Oct 2014 22:54:50 +0000 (15:54 -0700)]
altera-stapl: replace strnicmp with strncasecmp
The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics and
a slightly buggy strncasecmp. The latter is the POSIX name, so strnicmp
was renamed to strncasecmp, and strnicmp made into a wrapper for the new
strncasecmp to avoid breaking existing users.
To allow the compat wrapper strnicmp to be removed at some point in the
future, and to avoid the extra indirection cost, do
s/strnicmp/strncasecmp/g.
Rasmus Villemoes [Mon, 13 Oct 2014 22:54:48 +0000 (15:54 -0700)]
input: edt-ft5x06: replace strnicmp with strncasecmp
The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics and
a slightly buggy strncasecmp. The latter is the POSIX name, so strnicmp
was renamed to strncasecmp, and strnicmp made into a wrapper for the new
strncasecmp to avoid breaking existing users.
To allow the compat wrapper strnicmp to be removed at some point in the
future, and to avoid the extra indirection cost, do
s/strnicmp/strncasecmp/g.
Rasmus Villemoes [Mon, 13 Oct 2014 22:54:46 +0000 (15:54 -0700)]
ib_srpt: replace strnicmp with strncasecmp
The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics and
a slightly buggy strncasecmp. The latter is the POSIX name, so strnicmp
was renamed to strncasecmp, and strnicmp made into a wrapper for the new
strncasecmp to avoid breaking existing users.
To allow the compat wrapper strnicmp to be removed at some point in the
future, and to avoid the extra indirection cost, do
s/strnicmp/strncasecmp/g.
Rasmus Villemoes [Mon, 13 Oct 2014 22:54:44 +0000 (15:54 -0700)]
scsi: replace strnicmp with strncasecmp
The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics and
a slightly buggy strncasecmp. The latter is the POSIX name, so strnicmp
was renamed to strncasecmp, and strnicmp made into a wrapper for the new
strncasecmp to avoid breaking existing users.
To allow the compat wrapper strnicmp to be removed at some point in the
future, and to avoid the extra indirection cost, do
s/strnicmp/strncasecmp/g.
Rasmus Villemoes [Mon, 13 Oct 2014 22:54:42 +0000 (15:54 -0700)]
batman-adv: replace strnicmp with strncasecmp
The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics and
a slightly buggy strncasecmp. The latter is the POSIX name, so strnicmp
was renamed to strncasecmp, and strnicmp made into a wrapper for the new
strncasecmp to avoid breaking existing users.
To allow the compat wrapper strnicmp to be removed at some point in the
future, and to avoid the extra indirection cost, do
s/strnicmp/strncasecmp/g.
Rasmus Villemoes [Mon, 13 Oct 2014 22:54:39 +0000 (15:54 -0700)]
isofs: replace strnicmp with strncasecmp
The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics and
a slightly buggy strncasecmp. The latter is the POSIX name, so strnicmp
was renamed to strncasecmp, and strnicmp made into a wrapper for the new
strncasecmp to avoid breaking existing users.
To allow the compat wrapper strnicmp to be removed at some point in the
future, and to avoid the extra indirection cost, do
s/strnicmp/strncasecmp/g.
Rasmus Villemoes [Mon, 13 Oct 2014 22:54:37 +0000 (15:54 -0700)]
ocfs2: replace strnicmp with strncasecmp
The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics and
a slightly buggy strncasecmp. The latter is the POSIX name, so strnicmp
was renamed to strncasecmp, and strnicmp made into a wrapper for the new
strncasecmp to avoid breaking existing users.
To allow the compat wrapper strnicmp to be removed at some point in the
future, and to avoid the extra indirection cost, do
s/strnicmp/strncasecmp/g.
Rasmus Villemoes [Mon, 13 Oct 2014 22:54:35 +0000 (15:54 -0700)]
cifs: replace strnicmp with strncasecmp
The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics and
a slightly buggy strncasecmp. The latter is the POSIX name, so strnicmp
was renamed to strncasecmp, and strnicmp made into a wrapper for the new
strncasecmp to avoid breaking existing users.
To allow the compat wrapper strnicmp to be removed at some point in the
future, and to avoid the extra indirection cost, do
s/strnicmp/strncasecmp/g.
Rasmus Villemoes [Mon, 13 Oct 2014 22:54:33 +0000 (15:54 -0700)]
video: fbdev: replace strnicmp with strncasecmp
The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics and
a slightly buggy strncasecmp. The latter is the POSIX name, so strnicmp
was renamed to strncasecmp, and strnicmp made into a wrapper for the new
strncasecmp to avoid breaking existing users.
To allow the compat wrapper strnicmp to be removed at some point in the
future, and to avoid the extra indirection cost, do
s/strnicmp/strncasecmp/g.
Rasmus Villemoes [Mon, 13 Oct 2014 22:54:31 +0000 (15:54 -0700)]
netfilter: replace strnicmp with strncasecmp
The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics and
a slightly buggy strncasecmp. The latter is the POSIX name, so strnicmp
was renamed to strncasecmp, and strnicmp made into a wrapper for the new
strncasecmp to avoid breaking existing users.
To allow the compat wrapper strnicmp to be removed at some point in the
future, and to avoid the extra indirection cost, do
s/strnicmp/strncasecmp/g.
Rasmus Villemoes [Mon, 13 Oct 2014 22:54:29 +0000 (15:54 -0700)]
ARM: replace strnicmp with strncasecmp
The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics and
a slightly buggy strncasecmp. The latter is the POSIX name, so strnicmp
was renamed to strncasecmp, and strnicmp made into a wrapper for the new
strncasecmp to avoid breaking existing users.
To allow the compat wrapper strnicmp to be removed at some point in the
future, and to avoid the extra indirection cost, do
s/strnicmp/strncasecmp/g.
Rasmus Villemoes [Mon, 13 Oct 2014 22:54:27 +0000 (15:54 -0700)]
lib: string: Make all calls to strnicmp into calls to strncasecmp
The previous patch made strnicmp into a wrapper for strncasecmp.
This patch makes all in-tree users of strnicmp call strncasecmp
directly, while still making sure that the strnicmp symbol can be used
by out-of-tree modules. It should be considered a temporary hack until
all in-tree callers have been converted.
Rasmus Villemoes [Mon, 13 Oct 2014 22:54:25 +0000 (15:54 -0700)]
lib/string.c: remove duplicated function
lib/string.c contains two functions, strnicmp and strncasecmp, which do
roughly the same thing, namely compare two strings case-insensitively up
to a given bound. They have slightly different implementations, but the
only important difference is that strncasecmp doesn't handle len==0
appropriately; it effectively becomes strcasecmp in that case. strnicmp
correctly says that two strings are always equal in their first 0
characters.
strncasecmp is the POSIX name for this functionality. So rename the
non-broken function to the standard name. To minimize the impact on the
rest of the kernel (and since both are exported to modules), make strnicmp
a wrapper for strncasecmp.
Tim Gardner [Mon, 13 Oct 2014 22:54:20 +0000 (15:54 -0700)]
scripts/sortextable: suppress warning: `relocs_size' may be used uninitialized
In file included from scripts/sortextable.c:194:0:
scripts/sortextable.c: In function `main':
scripts/sortextable.h:176:3: warning: `relocs_size' may be used uninitialized in this function [-Wmaybe-uninitialized]
memset(relocs, 0, relocs_size);
^
scripts/sortextable.h:106:6: note: `relocs_size' was declared here
int relocs_size;
^
In file included from scripts/sortextable.c:192:0:
scripts/sortextable.h:176:3: warning: `relocs_size' may be used uninitialized in this function [-Wmaybe-uninitialized]
memset(relocs, 0, relocs_size);
^
scripts/sortextable.h:106:6: note: `relocs_size' was declared here
int relocs_size;
^
Mark Rustad [Mon, 13 Oct 2014 22:54:16 +0000 (15:54 -0700)]
ipc: resolve shadow warnings
Resolve some shadow warnings produced in W=2 builds by changing the name
of some parameters and local variables. Change instances of "s64"
because that clashes with the well-known typedef. Also change a local
variable with the name "up" because that clashes with the name of of the
"up" function for semaphores. These are hazards so eliminate the
hazards by renaming them.
Oleg Nesterov [Mon, 13 Oct 2014 22:54:12 +0000 (15:54 -0700)]
ipc/shm: kill the historical/wrong mm->start_stack check
do_shmat() is the only user of ->start_stack (proc just reports its
value), and this check looks ugly and wrong.
The reason for this check is not clear at all, and it wrongly assumes that
the stack can only grow down.
But the main problem is that in general mm->start_stack has nothing to do
with stack_vma->vm_start. Not only the application can switch to another
stack and even unmap this area, setup_arg_pages() expands the stack
without updating mm->start_stack during exec(). This means that in the
likely case "addr > start_stack - size - PAGE_SIZE * 5" is simply
impossible after find_vma_intersection() == F, or the stack can't grow
anyway because of RLIMIT_STACK.
Mike Travis [Mon, 13 Oct 2014 22:54:05 +0000 (15:54 -0700)]
x86: use optimized ioresource lookup in ioremap function
Use the optimized ioresource lookup, "region_is_ram", for the ioremap
function. If the region is not found, it falls back to the
"page_is_ram" function. If it is found and it is RAM, then the usual
warning message is issued, and the ioremap operation is aborted.
Otherwise, the ioremap operation continues.
Mike Travis [Mon, 13 Oct 2014 22:54:03 +0000 (15:54 -0700)]
x86: optimize resource lookups for ioremap
We have a large university system in the UK that is experiencing very long
delays modprobing the driver for a specific I/O device. The delay is from
8-10 minutes per device and there are 31 devices in the system. This 4 to
5 hour delay in starting up those I/O devices is very much a burden on the
customer.
There are two causes for requiring a restart/reload of the drivers. First
is periodic preventive maintenance (PM) and the second is if any of the
devices experience a fatal error. Both of these trigger this excessively
long delay in bringing the system back up to full capability.
The problem was tracked down to a very slow IOREMAP operation and the
excessively long ioresource lookup to insure that the user is not
attempting to ioremap RAM. These patches provide a speed up to that
function.
The modprobe time appears to be affected quite a bit by previous activity
on the ioresource list, which I suspect is due to cache preloading. While
the overall improvement is impacted by other overhead of starting the
devices, this drastically improves the modprobe time.
Also our system is considerably smaller so the percentages gained will not
be the same. Best case improvement with the modprobe on our 20 device
smallish system was from 'real 5m51.913s' to 'real 0m18.275s'.
This patch (of 2):
Since the ioremap operation is verifying that the specified address range
is NOT RAM, it will search the entire ioresource list if the condition is
true. To make matters worse, it does this one 4k page at a time. For a
128M BAR region this is 32 passes to determine the entire region does not
contain any RAM addresses.
This patch provides another resource lookup function, region_is_ram, that
searches for the entire region specified, verifying that it is completely
contained within the resource region. If it is found, then it is checked
to be RAM or not, within a single pass.
The return result reflects if it was found or not (-1), and whether it is
RAM (1) or not (0). This allows the caller to fallback to the previous
page by page search if it was not found.
Vivek Goyal [Mon, 13 Oct 2014 22:53:46 +0000 (15:53 -0700)]
kexec-bzimage64: fix sparse warnings
David Howells brought to my attention the mails generated by kbuild test
bot and following sparse warnings were present. This patch fixes these
warnings.
arch/x86/kernel/kexec-bzimage64.c:270:5: warning: symbol 'bzImage64_probe' was not declared. Should it be static?
arch/x86/kernel/kexec-bzimage64.c:328:6: warning: symbol 'bzImage64_load' was not declared. Should it be static?
arch/x86/kernel/kexec-bzimage64.c:517:5: warning: symbol 'bzImage64_cleanup' was not declared. Should it be static?
arch/x86/kernel/kexec-bzimage64.c:531:5: warning: symbol 'bzImage64_verify_sig' was not declared. Should it be static?
arch/x86/kernel/kexec-bzimage64.c:546:23: warning: symbol 'kexec_bzImage64_ops' was not declared. Should it be static?
Baoquan He [Mon, 13 Oct 2014 22:53:42 +0000 (15:53 -0700)]
kexec: check if crashk_res_low exists when exclude it from crash mem ranges
Add a check if crashk_res_low exists just like GART region does. If
crashk_res_low doesn't exist, calling exclude_mem_range is unnecessary.
Meanwhile, since crashk_res_low has been initialized at definition, it's
safe just use "if (crashk_low_res.end)" to check if it's exist. And this
can make it consistent with other places of check.
Baoquan He [Mon, 13 Oct 2014 22:53:40 +0000 (15:53 -0700)]
kexec: take the segment adding out of locate_mem_hole functions
In locate_mem_hole functions, a memory hole is located and added as
kexec_segment. But from the name of locate_mem_hole, it should only take
responsibility of searching a available memory hole to contain data of a
specified size.
So in this patch add a new field 'mem' into kexec_buf, then take that
kexec segment adding code out of locate_mem_hole_top_down and
locate_mem_hole_bottom_up. This make clear of the functionality of
locate_mem_hole just like it declars to do. And by this
locate_mem_hole_callback chould be used later if anyone want to locate a
memory hole for other use.
Meanwhile Vivek suggested opening code function __kexec_add_segment(),
that way we have to retreive ksegment pointer once and it is easy to read.
So just do it in this patch and remove __kexec_add_segment() since no one
use it anymore.
Oleg Nesterov [Mon, 13 Oct 2014 22:53:35 +0000 (15:53 -0700)]
coredump: add %i/%I in core_pattern to report the tid of the crashed thread
format_corename() can only pass the leader's pid to the core handler,
but there is no simple way to figure out which thread originated the
coredump.
As Jan explains, this also means that there is no simple way to create
the backtrace of the crashed process:
As programs are mostly compiled with implicit gcc -fomit-frame-pointer
one needs program's .eh_frame section (equivalently PT_GNU_EH_FRAME
segment) or .debug_frame section. .debug_frame usually is present only
in separate debug info files usually not even installed on the system.
While .eh_frame is a part of the executable/library (and it is even
always mapped for C++ exceptions unwinding) it no longer has to be
present anywhere on the disk as the program could be upgraded in the
meantime and the running instance has its executable file already
unlinked from disk.
One possibility is to echo 0x3f >/proc/*/coredump_filter and dump all
the file-backed memory including the executable's .eh_frame section.
But that can create huge core files, for example even due to mmapped
data files.
Other possibility would be to read .eh_frame from /proc/PID/mem at the
core_pattern handler time of the core dump. For the backtrace one needs
to read the register state first which can be done from core_pattern
handler:
ptrace(PTRACE_SEIZE, tid, 0, PTRACE_O_TRACEEXIT)
close(0); // close pipe fd to resume the sleeping dumper
waitpid(); // should report EXIT
PTRACE_GETREGS or other requests
The remaining problem is how to get the 'tid' value of the crashed
thread. It could be read from the first NT_PRSTATUS note of the core
file but that makes the core_pattern handler complicated.
Unfortunately %t is already used so this patch uses %i/%I.
Automatic Bug Reporting Tool (https://github.com/abrt/abrt/wiki/overview)
is experimenting with this. It is using the elfutils
(https://fedorahosted.org/elfutils/) unwinder for generating the
backtraces. Apart from not needing matching executables as mentioned
above, another advantage is that we can get the backtrace without saving
the core (which might be quite large) to disk.
Oleg Nesterov [Mon, 13 Oct 2014 22:53:33 +0000 (15:53 -0700)]
signal: use BUILD_BUG() instead of _NSIG_WORDS_is_unsupported_size()
Kill _NSIG_WORDS_is_unsupported_size(), use BUILD_BUG() instead. This
simplifies the code, avoids the nested-externs warnings, and this way we
do not defer the problem to linker.
Also, fix the indentation in _SIG_SET_BINOP() and _SIG_SET_OP().
Note: this patch assumes that the code like "if (0) BUILD_BUG();" is
valid. If not (say __compiletime_error() is not defined and thus
__compiletime_error_fallback() uses a negative array) we should fix
BUILD_BUG() and/or BUILD_BUG_ON_MSG(). This code should be fine by
definition, this is the documented purpose of BUILD_BUG().
Andreas Rohner [Mon, 13 Oct 2014 22:53:22 +0000 (15:53 -0700)]
nilfs2: improve the performance of fdatasync()
Support for fdatasync() has been implemented in NILFS2 for a long time,
but whenever the corresponding inode is dirty the implementation falls
back to a full-flegded sync(). Since every write operation has to
update the modification time of the file, the inode will almost always
be dirty and fdatasync() will fall back to sync() most of the time. But
this fallback is only necessary for a change of the file size and not
for a change of the various timestamps.
This patch adds a new flag NILFS_I_INODE_SYNC to differentiate between
those two situations.
* If it is set the file size was changed and a full sync is necessary.
* If it is not set then only the timestamps were updated and
fdatasync() can go ahead.
There is already a similar flag I_DIRTY_DATASYNC on the VFS layer with
the exact same semantics. Unfortunately it cannot be used directly,
because NILFS2 doesn't implement write_inode() and doesn't clear the VFS
flags when inodes are written out. So the VFS writeback thread can
clear I_DIRTY_DATASYNC at any time without notifying NILFS2. So
I_DIRTY_DATASYNC has to be mapped onto NILFS_I_INODE_SYNC in
nilfs_update_inode().
Andreas Rohner [Mon, 13 Oct 2014 22:53:20 +0000 (15:53 -0700)]
nilfs2: add missing blkdev_issue_flush() to nilfs_sync_fs()
Under normal circumstances nilfs_sync_fs() writes out the super block,
which causes a flush of the underlying block device. But this depends
on the THE_NILFS_SB_DIRTY flag, which is only set if the pointer to the
last segment crosses a segment boundary. So if only a small amount of
data is written before the call to nilfs_sync_fs(), no flush of the
block device occurs.
In the above case an additional call to blkdev_issue_flush() is needed.
To prevent unnecessary overhead, the new flag nilfs->ns_flushed_device
is introduced, which is cleared whenever new logs are written and set
whenever the block device is flushed. For convenience the function
nilfs_flush_device() is added, which contains the above logic.
Daniel Glöckner [Mon, 13 Oct 2014 22:53:16 +0000 (15:53 -0700)]
rtc-cmos: fix wakeup from S5 without CONFIG_PM_SLEEP
Commit b5ada4600dfd ("drivers/rtc/rtc-cmos.c: fix compilation warning
when !CONFIG_PM_SLEEP") broke wakeup from S5 by making cmos_poweroff a
nop unless CONFIG_PM_SLEEP was defined.
Fix this by restricting the #ifdef to cmos_resume and restoring the old
dependency on CONFIG_PM for cmos_suspend and cmos_poweroff.
Arnd Bergmann [Mon, 13 Oct 2014 22:53:10 +0000 (15:53 -0700)]
drivers/rtc/rtc-pcf8563.c: fix pcf8563_irq() error return value
As pointed out by Sergei Shtylyov, the pcf8563_irq function contains a
bug in the error handling: an interrupt handler is not supposed to
return an errno value but an 'enum irqreturn'.
Let's fix this by returning IRQ_NONE in case of a communication error.
Arnd Bergmann [Mon, 13 Oct 2014 22:53:07 +0000 (15:53 -0700)]
drivers/rtc/rtc-pcf8563.c: fix uninitialized use warning
gcc-4.9 found a potential condition under which the 'pending' variable
may be used uninitialized:
drivers/rtc/rtc-pcf8563.c: In function 'pcf8563_irq':
drivers/rtc/rtc-pcf8563.c:173:5: warning: 'pending' may be used uninitialized in this function [-Wmaybe-uninitialized]
This is because in the pcf8563_get_alarm_mode() function, we check any
nonzero return of pcf8563_read_block_data, but in the irq function we
only check for negative values, so a possible positive value does not
get detected if the compiler chooses not to inline the entire call
chain.
Checking for any non-zero value in the interrupt handler as well is just
as correct and lets the compiler know what we are doing, without needing
a bogus initialization.
rtc: add driver for Maxim 77802 PMIC Real-Time-Clock
The MAX7802 PMIC has a Real-Time-Clock (RTC) with two alarms. This
patch adds support for the RTC and is based on a driver added by Simon
Glass to the Chrome OS kernel 3.8 tree.
max77686_rtc_calculate_wday() is used to calculate the day of the week
to be filled in struct rtc_time but that function only calculates the
number of bits shifted. So the ffs() function can be used to find the
first bit set instead of a special function.
rtc: max77686: fail to probe if no RTC regmap irqchip is set
The max77686 mfd driver adds a regmap IRQ chip which creates an IRQ
domain that is used to map the virtual RTC alarm1 interrupt.
The RTC driver assumes that this will always be true since the PMIC IRQ
is a required property according to the max77686 DT binding doc. If an
"interrupts" property is not defined for a max77686 PMIC, then the mfd
probe function will fail and the RTC platform driver will never be
probed.
But even when it is not possible to probe the rtc-max77686 driver
without a regmap IRQ chip, it's better to explicitly check if the IRQ
chip data is not NULL and gracefully fail instead of getting an OOPS.
The MAX77686 RTC chip has two features called SMPL (Sudden Momentary
Power Loss) and WTSR (Watchdog Timeout and Software Resets). Support
for these features seems to be implemented in the driver but compilation
is disabled using a C pre-processor conditional.
This code has been disabled since the driver was original merged in
commit fca1dd031a28 ("rtc: max77686: add Maxim 77686 driver").
So, since this code has never been built, let's just remove it.
Doug Anderson [Mon, 13 Oct 2014 22:52:55 +0000 (15:52 -0700)]
rtc: max77686: Allow the max77686 rtc to wakeup the system
This series add support for the Real Time clock present in the Maxim 77802
Power Managment IC. The version number is quite high because it
previously was part of a bigger series [0] that aimed to add support for
all the devices in the max77802 PMIC. But now that the max77802
dependencies were already merged for 3.17, the series were split but I
kept the version numbering.
While working on the max77802 rtc support a lot of feedback was given and
the issues pointed out also apply to a driver for a similar PMIC RTC
(max77686). So patches 01/06 to 05/06 in the series are cleanups for the
max77686 driver and patch 06/06 adds the support for the max77802 RTC.
The series were tested on an Exynos5250 Snow (max77686) and
Exynos5420 Peach Pit (max77802) machines.
This patch (of 6):
The max77686 includes an RTC that keeps power during suspend. It's
convenient to be able to use it as a wakeup source.
Matti Vaittinen [Mon, 13 Oct 2014 22:52:48 +0000 (15:52 -0700)]
rtc: ds1307: add trickle charger device tree binding
Some DS13XX devices have "trickle chargers". Introduce a device tree
binding for specifying the trickle charger configuration for ds1339.
Only ds1339 dt binding is supported because this is the only chip I have.
I _assume_ the code would have worked on other allready supported chips.
However I cannot check the resistor values for the other chips or test
them. For other chips the driver code works as earlier Eg. it does not
check the dt bindings at all
Chris Zhong [Mon, 13 Oct 2014 22:52:44 +0000 (15:52 -0700)]
clk: RK808: add clkout driver for RK808
This is the initial version of the RK808 PMIC. This is a power management
IC for multimedia products. It provides regulators that are able to
supply power to processor cores and other components. The chip provides
other modules including RTC, Clockout.
Chris Zhong [Mon, 13 Oct 2014 22:52:42 +0000 (15:52 -0700)]
RTC: RK808: add RTC driver for RK808
This is the initial version of the RK808 PMIC. This is a power management
IC for multimedia products. It provides regulators that are able to
supply power to processor cores and other components. The chip provides
other modules including RTC, Clockout.
Uwe Kleine-König [Mon, 13 Oct 2014 22:52:39 +0000 (15:52 -0700)]
rtc: make of_device_ids const
of_device_ids (i.e. compatible strings and the respective data) are not
supposed to change at runtime. All functions working with of_device_ids
provided by <linux/of.h> work with const of_device_ids. This allows to
mark all struct of_device_id below drivers/rtc const, too.
Chanwoo Choi [Mon, 13 Oct 2014 22:52:35 +0000 (15:52 -0700)]
rtc: s3c: add support for RTC of Exynos3250 SoC
Add support for RTC of Exynos3250 SoC. The Exynos3250 needs source
clock(32.768KHz) for RTC block. If source clock of RTC is registerd on
clock list of common clk framework, Exynos RTC drvier have to control
this clock.
Clock list for s3c-rtc device:
- rtc : CLK_RTC of CLK_GATE_IP_PERIR is gate clock for RTC.
- rtc_src : XrtcXTI is 32.768.kHz source clock for RTC.
(XRTCXTI: Specifies a clock from 32.768 kHz crystal pad with XRTCXTI and
XRTCXTO pins. RTC uses this clock as the source of a real-time clock.)
Chanwoo Choi [Mon, 13 Oct 2014 22:52:33 +0000 (15:52 -0700)]
rtc: s3c: add s3c_rtc_data structure to use variant data instead of s3c_cpu_type
Add s3c_rtc_data structure to variant data according to SoC type. The
s3c_rtc_data structure includes some functions to control RTC operation
and specific data dependent on SoC type.
Chanwoo Choi [Mon, 13 Oct 2014 22:52:31 +0000 (15:52 -0700)]
rtc: s3c: remove warning message when checking coding style with checkpatch script
Remove warning message when checking codeing style with checkpatch script
and reduce un-necessary i2c read operation on s3c_rtc_enable.
WARNING: line over 80 characters
#406: FILE: drivers/rtc/rtc-s3c.c:406:
+ if ((readw(info->base + S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0) {
WARNING: line over 80 characters
#414: FILE: drivers/rtc/rtc-s3c.c:414:
+ if ((readw(info->base + S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)) {
WARNING: line over 80 characters
#422: FILE: drivers/rtc/rtc-s3c.c:422:
+ if ((readw(info->base + S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)) {
WARNING: Missing a blank line after declarations
#451: FILE: drivers/rtc/rtc-s3c.c:451:
+ struct s3c_rtc_drv_data *data;
+ if (pdev->dev.of_node) {
WARNING: Missing a blank line after declarations
#453: FILE: drivers/rtc/rtc-s3c.c:453:
+ const struct of_device_id *match;
+ match = of_match_node(s3c_rtc_dt_match, pdev->dev.of_node);
Chanwoo Choi [Mon, 13 Oct 2014 22:52:28 +0000 (15:52 -0700)]
rtc: s3c: define s3c_rtc structure to remove global variables.
Define s3c_rtc structure including necessary variables for S3C RTC device
instead of global variables. This patch improves the readability by
removing global variables.
NeilBrown [Mon, 13 Oct 2014 22:52:22 +0000 (15:52 -0700)]
autofs4: d_manage() should return -EISDIR when appropriate in rcu-walk mode.
If rcu-walk mode we don't *have* to return -EISDIR for non-mount-traps
as we will simply drop into REF-walk and handling DCACHE_NEED_AUTOMOUNT
dentrys the slow way. But it is better if we do when possible.
In 'oz_mode', use the same condition as ref-walk: if not a mountpoint,
then it must be -EISDIR.
In regular mode there are most tests needed. Most of them can be
performed without taking any spinlocks. If we find a directory that
isn't obviously empty, and isn't mounted on, we need to call
'simple_empty()' which does take a spinlock. If this turned out to hurt
performance, some other approach could be found to signal when a
directory is known to be empty.
NeilBrown [Mon, 13 Oct 2014 22:52:20 +0000 (15:52 -0700)]
autofs4: avoid taking fs_lock during rcu-walk
->fs_lock protects AUTOFS_INF_EXPIRING. We need to be sure that once
the flag is set, no new references beneath the dentry are taken. So
rcu-walk currently needs to take fs_lock before checking the flag. This
hurts performance.
Change the expiry to a two-stage process. First set AUTOFS_INF_NO_RCU
which forces any path walk into ref-walk mode, then drop the lock and
call synchronize_rcu(). Once that returns we can be sure no rcu-walk is
active beneath the dentry and we can check reference counts again.
Now during an RCU-walk we can test AUTOFS_INF_EXPIRING without taking
the lock as along as we test AUTOFS_INF_NO_RCU too. If either are set,
we must abort the RCU-walk If neither are set, we know that refcounts
will be tested again after we finish the RCU-walk so we are safe to
continue.
->fs_lock is still taken in d_manage() to check for a non-trap
directory. That will be resolved in the next patch.
NeilBrown [Mon, 13 Oct 2014 22:52:14 +0000 (15:52 -0700)]
autofs4: allow RCU-walk to walk through autofs4
This series teaches autofs about RCU-walk so that we don't drop straight
into REF-walk when we hit an autofs directory, and so that we avoid
spinlocks as much as possible when performing an RCU-walk.
This is needed so that the benefits of the recent NFS support for
RCU-walk are fully available when NFS filesystems are automounted.
Patches have been carefully reviewed and tested both with test suites
and in production - thanks a lot to Ian Kent for his support there.
This patch (of 6):
Any attempt to look up a pathname that passes though an autofs4 mount is
currently forced out of RCU-walk into REF-walk.
This can significantly hurt performance of many-thread work loads on
many-core systems, especially if the automounted filesystem supports
RCU-walk but doesn't get to benefit from it.
So if autofs4_d_manage is called with rcu_walk set, only fail with -ECHILD
if it is necessary to wait longer than a spinlock.
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