Currently we use per-cpu array to hold pointers to preallocated nodes.
Let's replace it with linked list. On x86_64 it saves 256 bytes in
per-cpu ELF section which may translate into freeing up 2MB of memory for
NR_CPUS==8192.
[akpm@linux-foundation.org: fix comment, coding style]
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
bitmap_print_to_pagebuf uses scnprintf to copy the cpumask/list to page
buffer. It handles the newline and trailing null character explicitly.
It's unnecessary and also partially duplicated as scnprintf already adds
trailing null character. The newline can be passed through format
string to scnprintf. This patch does that simplification.
However theoretically there's one behavior difference: when the buffer
is too small, the original code would still output '\n' at the end while
the new code(with this patch) would just continue to print the formatted
string. Since this function is dealing with only page buffers, it's
highly unlikely to hit that corner case.
This patch will help in auditing the users of bitmap_print_to_pagebuf to
verify that the buffer passed is large enough and get rid of it
completely by replacing them with direct scnprintf()
[akpm@linux-foundation.org: tweak comment]
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Suggested-by: Pawel Moll <Pawel.Moll@arm.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
bitmap_parselist("", &mask, nmaskbits) will erroneously set bit zero in
the mask. The same bug is visible in cpumask_parselist() since it is
layered on top of the bitmask code, e.g. if you boot with "isolcpus=",
you will actually end up with cpu zero isolated.
The bug was introduced in commit 4b060420a5 ("bitmap, irq: add
smp_affinity_list interface to /proc/irq") when bitmap_parselist() was
generalized to support userspace as well as kernelspace.
Fixes: 4b060420a5 ("bitmap, irq: add smp_affinity_list interface to /proc/irq")
Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This makes it easier to copy/paste names with periods to email clients.
All the other names with commas already have quotation marks.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This makes it easier to copy/paste names with periods to email clients.
All the other names with periods already have quotation marks.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Section headers can be quite long and some are very long and duplicated
for many initial characters.
The current maximum length emitted for a section header is 20 bytes (or
17 bytes then ... when the section header length is > 20).
Change that length to 50 so more of the section is shown.
Example new output:
$ ./scripts/get_maintainer.pl -f drivers/net/ethernet/broadcom/bnx2x/
Ariel Elior <ariel.elior@qlogic.com> (supporter:BROADCOM BNX2X 10 GIGABIT ETHERNET DRIVER)
netdev@vger.kernel.org (open list:BROADCOM BNX2X 10 GIGABIT ETHERNET DRIVER)
linux-kernel@vger.kernel.org (open list)
Old:
$ ./scripts/get_maintainer.pl -f drivers/net/ethernet/broadcom/bnx2x/
Ariel Elior <ariel.elior@qlogic.com> (supporter:BROADCOM BNX2X 10...)
netdev@vger.kernel.org (open list:BROADCOM BNX2X 10...)
linux-kernel@vger.kernel.org (open list)
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some people prefer not to be cc'd on patches. Add an ability to have a
file (.get_maintainer.ignore) with names and email addresses that are
excluded from being listed except when specifically listed as a maintainer
in a section.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch fixes drawbacks in heck_syslog_permissions() noticed by AKPM:
"from_file handling makes me cry.
That's not a boolean - it's an enumerated value with two values
currently defined.
But the code in check_syslog_permissions() treats it as a boolean and
also hardwires the knowledge that SYSLOG_FROM_PROC == 1 (or == `true`).
And the name is wrong: it should be called from_proc to match
SYSLOG_FROM_PROC."
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Josh Boyer <jwboyer@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The final version of commit 637241a900 ("kmsg: honor dmesg_restrict
sysctl on /dev/kmsg") lost few hooks, as result security_syslog() are
processed incorrectly:
- open of /dev/kmsg checks syslog access permissions by using
check_syslog_permissions() where security_syslog() is not called if
dmesg_restrict is set.
- syslog syscall and /proc/kmsg calls do_syslog() where security_syslog
can be executed twice (inside check_syslog_permissions() and then
directly in do_syslog())
With this patch security_syslog() is called once only in all
syslog-related operations regardless of dmesg_restrict value.
Fixes: 637241a900 ("kmsg: honor dmesg_restrict sysctl on /dev/kmsg")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Josh Boyer <jwboyer@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
printk logbuf keeps various metadata and optional key=value dictionary for
structured messages, both of which are stripped when messages are handed
to regular console drivers.
It can be useful to have this metadata and dictionary available to
netconsole consumers. This obviously makes logging via netconsole more
complete and the sequence number in particular is useful in environments
where messages may be lost or reordered in transit - e.g. when netconsole
is used to collect messages in a large cluster where packets may have to
travel congested hops to reach the aggregator. The lost and reordered
messages can easily be identified and handled accordingly using the
sequence numbers.
printk recently added extended console support which can be selected by
setting CON_EXTENDED flag. From console driver side, not much changes.
The only difference is that the text passed to the write callback is
formatted the same way as /dev/kmsg.
This patch implements extended console support for netconsole which can be
enabled by either prepending "+" to a netconsole boot param entry or
echoing 1 to "extended" file in configfs. When enabled, netconsole
transmits extended log messages with headers identical to /dev/kmsg
output.
There's one complication due to message fragments. netconsole limits the
maximum message size to 1k and messages longer than that are split into
multiple fragments. As all extended console messages should carry
matching headers and be uniquely identifiable, each extended message
fragment carries full copy of the metadata and an extra header field to
identify the specific fragment. The optional header is of the form
"ncfrag=OFF/LEN" where OFF is the byte offset into the message body and
LEN is the total length.
To avoid unnecessarily making printk format extended messages, Extended
netconsole is registered with printk when the first extended netconsole is
configured.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: David Miller <davem@davemloft.net>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Petr Mladek <pmladek@suse.cz>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, each dynamic netconsole_target uses its own separate mutex to
synchronize the configuration operations.
This patch replaces the per-netconsole_target mutexes with a single
mutex - dynamic_netconsole_mutex. The reduced granularity doesn't hurt
anything, the code is minutely simpler and this'd allow adding
operations which should be synchronized across all dynamic netconsoles.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: David Miller <davem@davemloft.net>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Petr Mladek <pmladek@suse.cz>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
write_msg() grabs target_list_lock and walks target_list invoking
netpool_send_udp() on each target. Curiously, it protects each iteration
with netconsole_target_get/put() even though it never releases
target_list_lock which protects all the members.
While this doesn't harm anything, it doesn't serve any purpose either.
The items on the list can't go away while target_list_lock is held.
Remove the unnecessary get/put pair.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: David Miller <davem@davemloft.net>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Petr Mladek <pmladek@suse.cz>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
printk log_buf keeps various metadata for each message including its
sequence number and timestamp. The metadata is currently available only
through /dev/kmsg and stripped out before passed onto console drivers. We
want this metadata to be available to console drivers too so that console
consumers can get full information including the metadata and dictionary,
which among other things can be used to detect whether messages got lost
in transit.
This patch implements support for extended console drivers. Consoles can
indicate that they want extended messages by setting the new CON_EXTENDED
flag and they'll be fed messages formatted the same way as /dev/kmsg.
"<level>,<sequnum>,<timestamp>,<contflag>;<message text>\n"
If extended consoles exist, in-kernel fragment assembly is disabled. This
ensures that all messages emitted to consoles have full metadata including
sequence number. The contflag carries enough information to reassemble
the fragments from the reader side trivially. Note that this only affects
/dev/kmsg. Regular console and /proc/kmsg outputs are not affected by
this change.
* Extended message formatting for console drivers is enabled iff there
are registered extended consoles.
* Comment describing /dev/kmsg message format updated to add missing
contflag field and help distinguishing variable from verbatim terms.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: David Miller <davem@davemloft.net>
Cc: Kay Sievers <kay@vrfy.org>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patchset updates netconsole so that it can emit messages with the
same header as used in /dev/kmsg which gives neconsole receiver full log
information which enables things like structured logging and detection
of lost messages.
This patch (of 7):
devkmsg_read() uses 8k buffer and assumes that the formatted output
message won't overrun which seems safe given LOG_LINE_MAX, the current use
of dict and the escaping method being used; however, we're planning to use
devkmsg formatting wider and accounting for the buffer size properly isn't
that complicated.
This patch defines CONSOLE_EXT_LOG_MAX as 8192 and updates devkmsg_read()
so that it limits output accordingly.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: David Miller <davem@davemloft.net>
Cc: Kay Sievers <kay@vrfy.org>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The KERN_INFO prefix is being prepended to KERN_DEBUG when using the
dprink macro, Remove it as it is extraneous since we are printing the
message out as debug via dprintk().
Fixes smatch warning:
drivers/misc/altera-stapl/altera.c:2454 altera_init()
warn: KERN_* level not at start of string
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Igor M. Liplianin <liplianin@netup.ru>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
clone has some of the quirkiest syscall handling in the kernel, with a
pile of special cases, historical curiosities, and architecture-specific
calling conventions. In particular, clone with CLONE_SETTLS accepts a
parameter "tls" that the C entry point completely ignores and some
assembly entry points overwrite; instead, the low-level arch-specific
code pulls the tls parameter out of the arch-specific register captured
as part of pt_regs on entry to the kernel. That's a massive hack, and
it makes the arch-specific code only work when called via the specific
existing syscall entry points; because of this hack, any new clone-like
system call would have to accept an identical tls argument in exactly
the same arch-specific position, rather than providing a unified system
call entry point across architectures.
The first patch allows architectures to handle the tls argument via
normal C parameter passing, if they opt in by selecting
HAVE_COPY_THREAD_TLS. The second patch makes 32-bit and 64-bit x86 opt
into this.
These two patches came out of the clone4 series, which isn't ready for
this merge window, but these first two cleanup patches were entirely
uncontroversial and have acks. I'd like to go ahead and submit these
two so that other architectures can begin building on top of this and
opting into HAVE_COPY_THREAD_TLS. However, I'm also happy to wait and
send these through the next merge window (along with v3 of clone4) if
anyone would prefer that.
This patch (of 2):
clone with CLONE_SETTLS accepts an argument to set the thread-local
storage area for the new thread. sys_clone declares an int argument
tls_val in the appropriate point in the argument list (based on the
various CLONE_BACKWARDS variants), but doesn't actually use or pass along
that argument. Instead, sys_clone calls do_fork, which calls
copy_process, which calls the arch-specific copy_thread, and copy_thread
pulls the corresponding syscall argument out of the pt_regs captured at
kernel entry (knowing what argument of clone that architecture passes tls
in).
Apart from being awful and inscrutable, that also only works because only
one code path into copy_thread can pass the CLONE_SETTLS flag, and that
code path comes from sys_clone with its architecture-specific
argument-passing order. This prevents introducing a new version of the
clone system call without propagating the same architecture-specific
position of the tls argument.
However, there's no reason to pull the argument out of pt_regs when
sys_clone could just pass it down via C function call arguments.
Introduce a new CONFIG_HAVE_COPY_THREAD_TLS for architectures to opt into,
and a new copy_thread_tls that accepts the tls parameter as an additional
unsigned long (syscall-argument-sized) argument. Change sys_clone's tls
argument to an unsigned long (which does not change the ABI), and pass
that down to copy_thread_tls.
Architectures that don't opt into copy_thread_tls will continue to ignore
the C argument to sys_clone in favor of the pt_regs captured at kernel
entry, and thus will be unable to introduce new versions of the clone
syscall.
Patch co-authored by Josh Triplett and Thiago Macieira.
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thiago Macieira <thiago.macieira@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 3876488444 ("include/stddef.h: Move offsetofend() from vfio.h
to a generic kernel header") added offsetofend outside the normal
include #ifndef/#endif guard. Move it inside.
Miscellanea:
o remove unnecessary blank line
o standardize offsetof macros whitespace style
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kirill A. Shutemov
Sudeep Holla
Daniel Wagner
Geert Uytterhoeven
Chris Metcalf
Andrew Morton
Joe Perches
Jim Davis
Vasily Averin
Tejun Heo
Colin Ian King
Josh Triplett
Kees Cook