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16 years agoftrace: fix some mistakes in error messages
Frédéric Weisbecker [Fri, 15 Aug 2008 19:08:22 +0000 (21:08 +0200)]
ftrace: fix some mistakes in error messages

This patch fixes some mistakes on the tracer in warning messages when
debugfs fails to create tracing files.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: srostedt@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agoftrace: scripts/recordmcount.pl cross-build hack
Ingo Molnar [Mon, 9 Jun 2008 18:54:22 +0000 (20:54 +0200)]
ftrace: scripts/recordmcount.pl cross-build hack

hack around:

 ld: Relocatable linking with relocations from format elf32-i386 (init/.tmp_gl_calibrate.o) to format elf64-x86-64 (init/.tmp_mx_calibrate.o) i  CC      arch/x86/mm/extable.o
 objcopy: 'init/.tmp_mx_calibrate.o': No such file
 rm: cannot remove `init/.tmp_mx_calibrate.o': No such file or directory
 ld: Relocatable linking with relocations from format elf32-i386 (arch/x86/mm/extable.o) to format elf64-x86-64 (arch/x86/mm/.tmp_mx_extable.o) is not supported
 mv: cannot stat `arch/x86/mm/.tmp_mx_extable.o': No such file or directory
 ld: Relocatable linking with relocations from format elf32-i386 (arch/x86/mm/fault.o) to format elf64-x86-64 (arch/x86/mm/.tmp_mx_fault.o) is not supported

Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agoftrace: ftrace_kill_atomic() build fix
Ingo Molnar [Fri, 15 Aug 2008 16:22:09 +0000 (18:22 +0200)]
ftrace: ftrace_kill_atomic() build fix

fix:

 kernel/built-in.o: In function `ftrace_dump':
 (.text+0x2e2ea): undefined reference to `ftrace_kill_atomic'

Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agoftrace: build fix
Ingo Molnar [Fri, 15 Aug 2008 15:48:02 +0000 (17:48 +0200)]
ftrace: build fix

fix:

 In file included from init/main.c:65:
 include/linux/ftrace.h:166: error: expected ‘,' or ‘;' before ‘{' token
 make[1]: *** [init/main.o] Error 1
 make: *** [init/main.o] Error 2

Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agoftrace: dump out ftrace buffers to console on panic
Steven Rostedt [Thu, 31 Jul 2008 02:36:46 +0000 (22:36 -0400)]
ftrace: dump out ftrace buffers to console on panic

At OLS I had a lot of interest to be able to have the ftrace buffers
dumped on panic.  Usually one would expect to uses kexec and examine
the buffers after a new kernel is loaded. But sometimes the resources
do not permit kdump and kexec, so having an option to still see the
sequence of events up to the crash is very advantageous.

This patch adds the option to have the ftrace buffers dumped to the
console in the latency_trace format on a panic. When the option is set,
the default entries per CPU buffer are lowered to 16384, since the writing
to the serial (if that is the console) may take an awful long time
otherwise.

[
 Changes since -v1:
  Got alpine to send correctly (as well as spell check working).
  Removed config option.
  Moved the static variables into ftrace_dump itself.
  Gave printk a log level.
]

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agoftrace: ftrace_printk doc moved
Steven Rostedt [Fri, 1 Aug 2008 20:45:49 +0000 (16:45 -0400)]
ftrace: ftrace_printk doc moved

Based on Randy Dunlap's suggestion, the ftrace_printk kernel-doc belongs
with the ftrace_printk macro that should be used. Not with the
__ftrace_printk internal function.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agoftrace: printk formatting infrastructure
Steven Rostedt [Fri, 1 Aug 2008 16:26:41 +0000 (12:26 -0400)]
ftrace: printk formatting infrastructure

This patch adds a feature that can help kernel developers debug their
code using ftrace.

  int ftrace_printk(const char *fmt, ...);

This records into the ftrace buffer using printf formatting. The entry
size in the buffers are still a fixed length. A new type has been added
that allows for more entries to be used for a single recording.

The start of the print is still the same as the other entries.

It returns the number of characters written to the ftrace buffer.

For example:

Having a module with the following code:

static int __init ftrace_print_test(void)
{
        ftrace_printk("jiffies are %ld\n", jiffies);
        return 0;
}

Gives me:

  insmod-5441  3...1 7569us : ftrace_print_test: jiffies are 4296626666

for the latency_trace file and:

          insmod-5441  [03]  1959.370498: ftrace_print_test jiffies are 4296626666

for the trace file.

Note: Only the infrastructure should go into the kernel. It is to help
facilitate debugging for other kernel developers. Calls to ftrace_printk
is not intended to be left in the kernel, and should be frowned upon just
like scattering printks around in the code.

But having this easily at your fingertips helps the debugging go faster
and bugs be solved quicker.

Maybe later on, we can hook this with markers and have their printf format
be sucked into ftrace output.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agoftrace: new continue entry - separate out from trace_entry
Steven Rostedt [Fri, 1 Aug 2008 16:26:40 +0000 (12:26 -0400)]
ftrace: new continue entry - separate out from trace_entry

Some tracers will need to work with more than one entry. In order to do this
the trace_entry structure was split into two fields. One for the start of
all entries, and one to continue an existing entry.

The trace_entry structure now has a "field" entry that consists of the previous
content of the trace_entry, and a "cont" entry that is just a string buffer
the size of the "field" entry.

Thanks to Andrew Morton for suggesting this idea.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agoftrace: remove old pointers to mcount
Steven Rostedt [Fri, 15 Aug 2008 02:47:19 +0000 (22:47 -0400)]
ftrace: remove old pointers to mcount

When a mcount pointer is recorded into a table, it is used to add or
remove calls to mcount (replacing them with nops). If the code is removed
via removing a module, the pointers still exist.  At modifying the code
a check is always made to make sure the code being replaced is the code
expected. In-other-words, the code being replaced is compared to what
it is expected to be before being replaced.

There is a very small chance that the code being replaced just happens
to look like code that calls mcount (very small since the call to mcount
is relative). To remove this chance, this patch adds ftrace_release to
allow module unloading to remove the pointers to mcount within the module.

Another change for init calls is made to not trace calls marked with
__init. The tracing can not be started until after init is done anyway.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agoftrace: move notrace to compiler.h
Steven Rostedt [Fri, 15 Aug 2008 02:47:18 +0000 (22:47 -0400)]
ftrace: move notrace to compiler.h

The notrace define belongs in compiler.h so that it can be used in
init.h

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agoftrace: do not show freed records in available_filter_functions
Steven Rostedt [Fri, 15 Aug 2008 02:47:17 +0000 (22:47 -0400)]
ftrace: do not show freed records in available_filter_functions

Seems that freed records can appear in the available_filter_functions list.
This patch fixes that.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agoftrace: use only 5 byte nops for x86
Steven Rostedt [Thu, 14 Aug 2008 22:05:05 +0000 (18:05 -0400)]
ftrace: use only 5 byte nops for x86

Mathieu Desnoyers revealed a bug in the original code. The nop that is
used to relpace the mcount caller can be a two part nop. This runs the
risk where a process can be preempted after executing the first nop, but
before the second part of the nop.

The ftrace code calls kstop_machine to keep multiple CPUs from executing
code that is being modified, but it does not protect against a task preempting
in the middle of a two part nop.

If the above preemption happens and the tracer is enabled, after the
kstop_machine runs, all those nops will be calls to the trace function.
If the preempted process that was preempted between the two nops is executed
again, it will execute half of the call to the trace function, and this
might crash the system.

This patch instead uses what both the latest Intel and AMD spec suggests.
That is the P6_NOP5 sequence of "0x0f 0x1f 0x44 0x00 0x00".

Note, some older CPUs and QEMU might fault on this nop, so this nop
is executed with fault handling first. If it detects a fault, it will then
use the code "0x66 0x66 0x66 0x66 0x90". If that faults, it will then
default to a simple "jmp 1f; .byte 0x00 0x00 0x00; 1:". The jmp is
not optimal but will do if the first two can not be executed.

TODO: Examine the cpuid to determine the nop to use.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agoftrace: x86 mcount stub
Steven Rostedt [Thu, 14 Aug 2008 19:45:12 +0000 (15:45 -0400)]
ftrace: x86 mcount stub

x86 now sets up the mcount locations through the build and no longer
needs to record the ip when the function is executed. This patch changes
the initial mcount to simply return. There's no need to do any other work.
If the ftrace start up test fails, the original mcount will be what everything
will use, so having this as fast as possible is a good thing.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agoftrace: enable using mcount recording on x86
Steven Rostedt [Thu, 14 Aug 2008 19:45:11 +0000 (15:45 -0400)]
ftrace: enable using mcount recording on x86

Enable the use of the __mcount_loc infrastructure on x86_64 and i386.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agoftrace: rebuild everything on change to FTRACE_MCOUNT_RECORD
Steven Rostedt [Thu, 14 Aug 2008 19:45:10 +0000 (15:45 -0400)]
ftrace: rebuild everything on change to FTRACE_MCOUNT_RECORD

When enabling or disabling CONFIG_FTRACE_MCOUNT_RECORD, we want a full
kernel compile to handle the adding of the __mcount_loc sections.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agoftrace: enable mcount recording for modules
Steven Rostedt [Thu, 14 Aug 2008 19:45:09 +0000 (15:45 -0400)]
ftrace: enable mcount recording for modules

This patch enables the loading of the __mcount_section of modules and
changing all the callers of mcount into nops.

The modification is done before the init_module function is called, so
again, we do not need to use kstop_machine to make these changes.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agoftrace: mcount call site on boot nops core
Steven Rostedt [Thu, 14 Aug 2008 19:45:08 +0000 (15:45 -0400)]
ftrace: mcount call site on boot nops core

This is the infrastructure to the converting the mcount call sites
recorded by the __mcount_loc section into nops on boot. It also allows
for using these sites to enable tracing as normal. When the __mcount_loc
section is used, the "ftraced" kernel thread is disabled.

This uses the current infrastructure to record the mcount call sites
as well as convert them to nops. The mcount function is kept as a stub
on boot up and not converted to the ftrace_record_ip function. We use the
ftrace_record_ip to only record from the table.

This patch does not handle modules. That comes with a later patch.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agoftrace: create __mcount_loc section
Steven Rostedt [Thu, 14 Aug 2008 19:45:07 +0000 (15:45 -0400)]
ftrace: create __mcount_loc section

This patch creates a section in the kernel called "__mcount_loc".
This will hold a list of pointers to the mcount relocation for
each call site of mcount.

For example:

objdump -dr init/main.o
[...]
Disassembly of section .text:

0000000000000000 <do_one_initcall>:
   0:   55                      push   %rbp
[...]
000000000000017b <init_post>:
 17b:   55                      push   %rbp
 17c:   48 89 e5                mov    %rsp,%rbp
 17f:   53                      push   %rbx
 180:   48 83 ec 08             sub    $0x8,%rsp
 184:   e8 00 00 00 00          callq  189 <init_post+0xe>
                        185: R_X86_64_PC32      mcount+0xfffffffffffffffc
[...]

We will add a section to point to each function call.

   .section __mcount_loc,"a",@progbits
[...]
   .quad .text + 0x185
[...]

The offset to of the mcount call site in init_post is an offset from
the start of the section, and not the start of the function init_post.
The mcount relocation is at the call site 0x185 from the start of the
.text section.

  .text + 0x185  == init_post + 0xa

We need a way to add this __mcount_loc section in a way that we do not
lose the relocations after final link.  The .text section here will
be attached to all other .text sections after final link and the
offsets will be meaningless.  We need to keep track of where these
.text sections are.

To do this, we use the start of the first function in the section.
do_one_initcall.  We can make a tmp.s file with this function as a reference
to the start of the .text section.

   .section __mcount_loc,"a",@progbits
[...]
   .quad do_one_initcall + 0x185
[...]

Then we can compile the tmp.s into a tmp.o

  gcc -c tmp.s -o tmp.o

And link it into back into main.o.

  ld -r main.o tmp.o -o tmp_main.o
  mv tmp_main.o main.o

But we have a problem.  What happens if the first function in a section
is not exported, and is a static function. The linker will not let
the tmp.o use it.  This case exists in main.o as well.

Disassembly of section .init.text:

0000000000000000 <set_reset_devices>:
   0:   55                      push   %rbp
   1:   48 89 e5                mov    %rsp,%rbp
   4:   e8 00 00 00 00          callq  9 <set_reset_devices+0x9>
                        5: R_X86_64_PC32        mcount+0xfffffffffffffffc

The first function in .init.text is a static function.

00000000000000a8 t __setup_set_reset_devices
000000000000105f t __setup_str_set_reset_devices
0000000000000000 t set_reset_devices

The lowercase 't' means that set_reset_devices is local and is not exported.
If we simply try to link the tmp.o with the set_reset_devices we end
up with two symbols: one local and one global.

 .section __mcount_loc,"a",@progbits
 .quad set_reset_devices + 0x10

00000000000000a8 t __setup_set_reset_devices
000000000000105f t __setup_str_set_reset_devices
0000000000000000 t set_reset_devices
                 U set_reset_devices

We still have an undefined reference to set_reset_devices, and if we try
to compile the kernel, we will end up with an undefined reference to
set_reset_devices, or even worst, it could be exported someplace else,
and then we will have a reference to the wrong location.

To handle this case, we make an intermediate step using objcopy.
We convert set_reset_devices into a global exported symbol before linking
it with tmp.o and set it back afterwards.

00000000000000a8 t __setup_set_reset_devices
000000000000105f t __setup_str_set_reset_devices
0000000000000000 T set_reset_devices

00000000000000a8 t __setup_set_reset_devices
000000000000105f t __setup_str_set_reset_devices
0000000000000000 T set_reset_devices

00000000000000a8 t __setup_set_reset_devices
000000000000105f t __setup_str_set_reset_devices
0000000000000000 t set_reset_devices

Now we have a section in main.o called __mcount_loc that we can place
somewhere in the kernel using vmlinux.ld.S and access it to convert
all these locations that call mcount into nops before starting SMP
and thus, eliminating the need to do this with kstop_machine.

Note, A well documented perl script (scripts/recordmcount.pl) is used
to do all this in one location.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agoftrace: mark lapic_wd_event() notrace
Ingo Molnar [Tue, 29 Jul 2008 10:36:02 +0000 (12:36 +0200)]
ftrace: mark lapic_wd_event() notrace

it can be called in the NMI path:

[    0.645999] calling  ftrace_dynamic_init+0x0/0xd6
[    0.647521] ------------[ cut here ]------------
[    0.647521] WARNING: at kernel/trace/ftrace.c:348 ftrace_record_ip+0x4e/0x252()
[    0.647521] Modules linked in:
[    0.647521] Pid: 15, comm: kstop1 Not tainted 2.6.27-rc1-tip #22686
[    0.647521]
[    0.647521] Call Trace:
[    0.647521]  <NMI>  [<ffffffff8024593f>] warn_on_slowpath+0x5d/0x84
[    0.647521]  [<ffffffff80220b99>] ? lapic_wd_event+0xb/0x5c
[    0.647521]  [<ffffffff80287b3b>] ftrace_record_ip+0x4e/0x252
[    0.647521]  [<ffffffff80211274>] mcount_call+0x5/0x31
[    0.647521]  [<ffffffff80220b9e>] ? lapic_wd_event+0x10/0x5c
[    0.647521]  [<ffffffff8083f3ec>] nmi_watchdog_tick+0x19d/0x1ad
[    0.647521]  [<ffffffff8083e875>] default_do_nmi+0x75/0x1e3
[    0.647521]  [<ffffffff8083f0b3>] do_nmi+0x5d/0x94
[    0.647521]  [<ffffffff8083e2d2>] nmi+0xa2/0xc2
[    0.647521]  [<ffffffff802b48c3>] ? check_bytes_and_report+0x11/0xcc
[    0.647521]  <<EOE>>  [<ffffffff80211274>] ? mcount_call+0x5/0x31
[    0.647521]  [<ffffffff802b49df>] check_object+0x61/0x1b0
[    0.647521]  [<ffffffff802b502a>] __slab_free+0x169/0x2ae
[    0.647521]  [<ffffffff80242dbf>] ? __cleanup_sighand+0x25/0x27
[    0.647521]  [<ffffffff80242dbf>] ? __cleanup_sighand+0x25/0x27
[    0.647521]  [<ffffffff802b60cd>] kmem_cache_free+0x85/0xb9
[    0.647521]  [<ffffffff80242dbf>] __cleanup_sighand+0x25/0x27
[    0.647521]  [<ffffffff80247b3d>] release_task+0x256/0x339
[    0.647521]  [<ffffffff802490b4>] do_exit+0x764/0x7ef
[    0.647521]  [<ffffffff8027624c>] __xchg+0x0/0x38
[    0.647521]  [<ffffffff8027619a>] ? stop_cpu+0x0/0xb2
[    0.647521]  [<ffffffff8027619a>] ? stop_cpu+0x0/0xb2
[    0.647521]  [<ffffffff8025922f>] kthread+0x4e/0x7b
[    0.647521]  [<ffffffff80212979>] child_rip+0xa/0x11
[    0.647521]  [<ffffffff80211c17>] ? restore_args+0x0/0x30
[    0.647521]  [<ffffffff802283a5>] ? native_load_tls+0x14/0x2e
[    0.647521]  [<ffffffff802591e1>] ? kthread+0x0/0x7b
[    0.647521]  [<ffffffff8021296f>] ? child_rip+0x0/0x11
[    0.647521]
[    0.647521] ---[ end trace 4eaa2a86a8e2da22 ]---
[    0.672032] initcall ftrace_dynamic_init+0x0/0xd6 returned 0 after 19 msecs

also mark it no-kprobes while at it.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agoftrace: ignore functions that cannot be kprobe-ed
Ingo Molnar [Tue, 29 Jul 2008 10:00:59 +0000 (12:00 +0200)]
ftrace: ignore functions that cannot be kprobe-ed

kprobes already has an extensive list of annotations for functions
that should not be instrumented. Add notrace annotations to these
functions as well.

This is particularly useful for functions called by the NMI path.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agotracepoints: use TABLE_SIZE macro
Mathieu Desnoyers [Thu, 24 Jul 2008 20:37:23 +0000 (16:37 -0400)]
tracepoints: use TABLE_SIZE macro

Steven Rostedt suggested:

| Wouldn't it look nicer to have: (TRACEPOINT_TABLE_SIZE - 1) ?

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agox86: fix mmiotrace 8-bit register decoding
Pekka Paalanen [Mon, 21 Jul 2008 15:49:56 +0000 (18:49 +0300)]
x86: fix mmiotrace 8-bit register decoding

When SIL, DIL, BPL or SPL registers were used in MMIO, the datum
was extracted from AH, BH, CH, or DH, which are incorrect.

Signed-off-by: Pekka Paalanen <pq@iki.fi>
Cc: "Vegard Nossum" <vegard.nossum@gmail.com>
Cc: "Steven Rostedt" <srostedt@redhat.com>
Cc: proski@gnu.org
Cc: "Pekka Enberg"
<penberg@cs.helsinki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agotracing: clean up tracepoints kconfig structure
Ingo Molnar [Wed, 23 Jul 2008 12:15:22 +0000 (14:15 +0200)]
tracing: clean up tracepoints kconfig structure

do not expose users to CONFIG_TRACEPOINTS - tracers can select it
just fine.

update ftrace to select CONFIG_TRACEPOINTS.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agosched: clean up tracepoints
Ingo Molnar [Wed, 23 Jul 2008 11:48:22 +0000 (13:48 +0200)]
sched: clean up tracepoints

make it a bit more structured hence more readable.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agotracing: disable tracepoints by default
Ingo Molnar [Wed, 23 Jul 2008 11:38:00 +0000 (13:38 +0200)]
tracing: disable tracepoints by default

while it's arguably low overhead, we dont enable new features by default.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agoftrace: port to tracepoints
Mathieu Desnoyers [Fri, 18 Jul 2008 16:16:17 +0000 (12:16 -0400)]
ftrace: port to tracepoints

Porting the trace_mark() used by ftrace to tracepoints. (cleanup)

Changelog :
- Change error messages : marker -> tracepoint

[ mingo@elte.hu: conflict resolutions ]
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Acked-by: 'Peter Zijlstra' <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agotracing, sched: LTTng instrumentation - scheduler
Mathieu Desnoyers [Fri, 18 Jul 2008 16:16:17 +0000 (12:16 -0400)]
tracing, sched: LTTng instrumentation - scheduler

Instrument the scheduler activity (sched_switch, migration, wakeups,
wait for a task, signal delivery) and process/thread
creation/destruction (fork, exit, kthread stop). Actually, kthread
creation is not instrumented in this patch because it is architecture
dependent. It allows to connect tracers such as ftrace which detects
scheduling latencies, good/bad scheduler decisions. Tools like LTTng can
export this scheduler information along with instrumentation of the rest
of the kernel activity to perform post-mortem analysis on the scheduler
activity.

About the performance impact of tracepoints (which is comparable to
markers), even without immediate values optimizations, tests done by
Hideo Aoki on ia64 show no regression. His test case was using hackbench
on a kernel where scheduler instrumentation (about 5 events in code
scheduler code) was added. See the "Tracepoints" patch header for
performance result detail.

Changelog :

- Change instrumentation location and parameter to match ftrace
  instrumentation, previously done with kernel markers.

[ mingo@elte.hu: conflict resolutions ]
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Acked-by: 'Peter Zijlstra' <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agotracing: tracepoints, samples
Mathieu Desnoyers [Fri, 18 Jul 2008 16:16:16 +0000 (12:16 -0400)]
tracing: tracepoints, samples

Tracepoint example code under samples/.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Acked-by: 'Peter Zijlstra' <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agotracing: tracepoints, documentation
Mathieu Desnoyers [Fri, 18 Jul 2008 16:16:16 +0000 (12:16 -0400)]
tracing: tracepoints, documentation

Documentation of tracepoint usage.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Acked-by: 'Peter Zijlstra' <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agotracing: Kernel Tracepoints
Mathieu Desnoyers [Fri, 18 Jul 2008 16:16:16 +0000 (12:16 -0400)]
tracing: Kernel Tracepoints

Implementation of kernel tracepoints. Inspired from the Linux Kernel
Markers. Allows complete typing verification by declaring both tracing
statement inline functions and probe registration/unregistration static
inline functions within the same macro "DEFINE_TRACE". No format string
is required. See the tracepoint Documentation and Samples patches for
usage examples.

Taken from the documentation patch :

"A tracepoint placed in code provides a hook to call a function (probe)
that you can provide at runtime. A tracepoint can be "on" (a probe is
connected to it) or "off" (no probe is attached). When a tracepoint is
"off" it has no effect, except for adding a tiny time penalty (checking
a condition for a branch) and space penalty (adding a few bytes for the
function call at the end of the instrumented function and adds a data
structure in a separate section).  When a tracepoint is "on", the
function you provide is called each time the tracepoint is executed, in
the execution context of the caller. When the function provided ends its
execution, it returns to the caller (continuing from the tracepoint
site).

You can put tracepoints at important locations in the code. They are
lightweight hooks that can pass an arbitrary number of parameters, which
prototypes are described in a tracepoint declaration placed in a header
file."

Addition and removal of tracepoints is synchronized by RCU using the
scheduler (and preempt_disable) as guarantees to find a quiescent state
(this is really RCU "classic"). The update side uses rcu_barrier_sched()
with call_rcu_sched() and the read/execute side uses
"preempt_disable()/preempt_enable()".

We make sure the previous array containing probes, which has been
scheduled for deletion by the rcu callback, is indeed freed before we
proceed to the next update. It therefore limits the rate of modification
of a single tracepoint to one update per RCU period. The objective here
is to permit fast batch add/removal of probes on _different_
tracepoints.

Changelog :
- Use #name ":" #proto as string to identify the tracepoint in the
  tracepoint table. This will make sure not type mismatch happens due to
  connexion of a probe with the wrong type to a tracepoint declared with
  the same name in a different header.
- Add tracepoint_entry_free_old.
- Change __TO_TRACE to get rid of the 'i' iterator.

Masami Hiramatsu <mhiramat@redhat.com> :
Tested on x86-64.

Performance impact of a tracepoint : same as markers, except that it
adds about 70 bytes of instructions in an unlikely branch of each
instrumented function (the for loop, the stack setup and the function
call). It currently adds a memory read, a test and a conditional branch
at the instrumentation site (in the hot path). Immediate values will
eventually change this into a load immediate, test and branch, which
removes the memory read which will make the i-cache impact smaller
(changing the memory read for a load immediate removes 3-4 bytes per
site on x86_32 (depending on mov prefixes), or 7-8 bytes on x86_64, it
also saves the d-cache hit).

About the performance impact of tracepoints (which is comparable to
markers), even without immediate values optimizations, tests done by
Hideo Aoki on ia64 show no regression. His test case was using hackbench
on a kernel where scheduler instrumentation (about 5 events in code
scheduler code) was added.

Quoting Hideo Aoki about Markers :

I evaluated overhead of kernel marker using linux-2.6-sched-fixes git
tree, which includes several markers for LTTng, using an ia64 server.

While the immediate trace mark feature isn't implemented on ia64, there
is no major performance regression. So, I think that we don't have any
issues to propose merging marker point patches into Linus's tree from
the viewpoint of performance impact.

I prepared two kernels to evaluate. The first one was compiled without
CONFIG_MARKERS. The second one was enabled CONFIG_MARKERS.

I downloaded the original hackbench from the following URL:
http://devresources.linux-foundation.org/craiger/hackbench/src/hackbench.c

I ran hackbench 5 times in each condition and calculated the average and
difference between the kernels.

    The parameter of hackbench: every 50 from 50 to 800
    The number of CPUs of the server: 2, 4, and 8

Below is the results. As you can see, major performance regression
wasn't found in any case. Even if number of processes increases,
differences between marker-enabled kernel and marker- disabled kernel
doesn't increase. Moreover, if number of CPUs increases, the differences
doesn't increase either.

Curiously, marker-enabled kernel is better than marker-disabled kernel
in more than half cases, although I guess it comes from the difference
of memory access pattern.

* 2 CPUs

Number of | without      | with         | diff     | diff    |
processes | Marker [Sec] | Marker [Sec] |   [Sec]  |   [%]   |
--------------------------------------------------------------
       50 |      4.811   |       4.872  |  +0.061  |  +1.27  |
      100 |      9.854   |      10.309  |  +0.454  |  +4.61  |
      150 |     15.602   |      15.040  |  -0.562  |  -3.6   |
      200 |     20.489   |      20.380  |  -0.109  |  -0.53  |
      250 |     25.798   |      25.652  |  -0.146  |  -0.56  |
      300 |     31.260   |      30.797  |  -0.463  |  -1.48  |
      350 |     36.121   |      35.770  |  -0.351  |  -0.97  |
      400 |     42.288   |      42.102  |  -0.186  |  -0.44  |
      450 |     47.778   |      47.253  |  -0.526  |  -1.1   |
      500 |     51.953   |      52.278  |  +0.325  |  +0.63  |
      550 |     58.401   |      57.700  |  -0.701  |  -1.2   |
      600 |     63.334   |      63.222  |  -0.112  |  -0.18  |
      650 |     68.816   |      68.511  |  -0.306  |  -0.44  |
      700 |     74.667   |      74.088  |  -0.579  |  -0.78  |
      750 |     78.612   |      79.582  |  +0.970  |  +1.23  |
      800 |     85.431   |      85.263  |  -0.168  |  -0.2   |
--------------------------------------------------------------

* 4 CPUs

Number of | without      | with         | diff     | diff    |
processes | Marker [Sec] | Marker [Sec] |   [Sec]  |   [%]   |
--------------------------------------------------------------
       50 |      2.586   |       2.584  |  -0.003  |  -0.1   |
      100 |      5.254   |       5.283  |  +0.030  |  +0.56  |
      150 |      8.012   |       8.074  |  +0.061  |  +0.76  |
      200 |     11.172   |      11.000  |  -0.172  |  -1.54  |
      250 |     13.917   |      14.036  |  +0.119  |  +0.86  |
      300 |     16.905   |      16.543  |  -0.362  |  -2.14  |
      350 |     19.901   |      20.036  |  +0.135  |  +0.68  |
      400 |     22.908   |      23.094  |  +0.186  |  +0.81  |
      450 |     26.273   |      26.101  |  -0.172  |  -0.66  |
      500 |     29.554   |      29.092  |  -0.461  |  -1.56  |
      550 |     32.377   |      32.274  |  -0.103  |  -0.32  |
      600 |     35.855   |      35.322  |  -0.533  |  -1.49  |
      650 |     39.192   |      38.388  |  -0.804  |  -2.05  |
      700 |     41.744   |      41.719  |  -0.025  |  -0.06  |
      750 |     45.016   |      44.496  |  -0.520  |  -1.16  |
      800 |     48.212   |      47.603  |  -0.609  |  -1.26  |
--------------------------------------------------------------

* 8 CPUs

Number of | without      | with         | diff     | diff    |
processes | Marker [Sec] | Marker [Sec] |   [Sec]  |   [%]   |
--------------------------------------------------------------
       50 |      2.094   |       2.072  |  -0.022  |  -1.07  |
      100 |      4.162   |       4.273  |  +0.111  |  +2.66  |
      150 |      6.485   |       6.540  |  +0.055  |  +0.84  |
      200 |      8.556   |       8.478  |  -0.078  |  -0.91  |
      250 |     10.458   |      10.258  |  -0.200  |  -1.91  |
      300 |     12.425   |      12.750  |  +0.325  |  +2.62  |
      350 |     14.807   |      14.839  |  +0.032  |  +0.22  |
      400 |     16.801   |      16.959  |  +0.158  |  +0.94  |
      450 |     19.478   |      19.009  |  -0.470  |  -2.41  |
      500 |     21.296   |      21.504  |  +0.208  |  +0.98  |
      550 |     23.842   |      23.979  |  +0.137  |  +0.57  |
      600 |     26.309   |      26.111  |  -0.198  |  -0.75  |
      650 |     28.705   |      28.446  |  -0.259  |  -0.9   |
      700 |     31.233   |      31.394  |  +0.161  |  +0.52  |
      750 |     34.064   |      33.720  |  -0.344  |  -1.01  |
      800 |     36.320   |      36.114  |  -0.206  |  -0.57  |
--------------------------------------------------------------

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: 'Peter Zijlstra' <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
16 years agoMerge phase #5 (misc) of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux...
Linus Torvalds [Mon, 13 Oct 2008 16:54:35 +0000 (09:54 -0700)]
Merge phase #5 (misc) of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

Merges oprofile, timers/hpet, x86/traps, x86/time, and x86/core misc items.

* 'x86-core-v4-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (132 commits)
  x86: change early_ioremap to use slots instead of nesting
  x86: adjust dependencies for CONFIG_X86_CMOV
  dumpstack: x86: various small unification steps, fix
  x86: remove additional_cpus
  x86: remove additional_cpus configurability
  x86: improve UP kernel when CPU-hotplug and SMP is enabled
  dumpstack: x86: various small unification steps
  dumpstack: i386: make kstack= an early boot-param and add oops=panic
  dumpstack: x86: use log_lvl and unify trace formatting
  dumptrace: x86: consistently include loglevel, print stack switch
  dumpstack: x86: add "end" parameter to valid_stack_ptr and print_context_stack
  dumpstack: x86: make printk_address equal
  dumpstack: x86: move die_nmi to dumpstack_32.c
  traps: x86: finalize unification of traps.c
  traps: x86: make traps_32.c and traps_64.c equal
  traps: x86: various noop-changes preparing for unification of traps_xx.c
  traps: x86_64: use task_pid_nr(tsk) instead of tsk->pid in do_general_protection
  traps: i386: expand clear_mem_error and remove from mach_traps.h
  traps: x86_64: make io_check_error equal to the one on i386
  traps: i386: use preempt_conditional_sti/cli in do_int3
  ...

16 years agotty: rename the remaining oddly named n_tty functions
Alan Cox [Mon, 13 Oct 2008 09:46:24 +0000 (10:46 +0100)]
tty: rename the remaining oddly named n_tty functions

Original idea for this from a patch by Rodolfo Giometti which merges various
bits of PPS support

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agofs3270: Correct error returns
Alan Cox [Mon, 13 Oct 2008 09:46:09 +0000 (10:46 +0100)]
fs3270: Correct error returns

Drop the kernel lock further and also correct cases where we set rc to an
error code, and then return 0

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agofs3270: remove extra locks
Alan Cox [Mon, 13 Oct 2008 09:45:52 +0000 (10:45 +0100)]
fs3270: remove extra locks

get_current_tty now does internal locking and returns a referenced object,
thus our use of tty_mutex here can go away.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: tty_io.c shadows sparse fix
Jason Wessel [Mon, 13 Oct 2008 09:45:36 +0000 (10:45 +0100)]
tty: tty_io.c shadows sparse fix

drivers/char/tty_io.c:1413:17: warning: symbol 'buf' shadows an earlier one
drivers/char/tty_io.c:1379:20: originally declared here

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agoserial: fix device name reporting when minor space is shared between drivers
David S. Miller [Mon, 13 Oct 2008 09:45:26 +0000 (10:45 +0100)]
serial: fix device name reporting when minor space is shared between drivers

The multiple drivers share the minor space occupied by a particular major
number, the actual index within the device name's space is indicated by
the tty_driver->name_base + uart_port->line

Another usable formula is (uart_driver->minor - MINOR_BASE) + port->line

Use those to print the device names properly in such situations in
serial_core.c and 8250.c

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agoapplicom: Fix an unchecked user ioctl range and an error return
Alan Cox [Mon, 13 Oct 2008 09:45:17 +0000 (10:45 +0100)]
applicom: Fix an unchecked user ioctl range and an error return

Closes bug #11408 by checking the card index range for command 0
Fixes the ioctl to return ENOTTY which is correct for unknown ioctls

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: Minor tidyups and document fixes for n_tty
Alan Cox [Mon, 13 Oct 2008 09:45:06 +0000 (10:45 +0100)]
tty: Minor tidyups and document fixes for n_tty

Remove/fix some bogus NULL checks, comment some locking etc

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: Remove lots of NULL checks
Alan Cox [Mon, 13 Oct 2008 09:44:57 +0000 (10:44 +0100)]
tty: Remove lots of NULL checks

Many tty drivers contain 'can't happen' checks against NULL pointers passed
in by the tty layer. These have never been possible to occur. Even more
importantly if they ever do occur we want to know as it would be a serious
bug.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: fix up gigaset a bit
Alan Cox [Mon, 13 Oct 2008 09:44:43 +0000 (10:44 +0100)]
tty: fix up gigaset a bit

Stephen's fixes reminded me that gigaset is still rather broken so fix it up
a bit

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: Fallout from tty-move-canon-specials
Stephen Rothwell [Mon, 13 Oct 2008 09:44:33 +0000 (10:44 +0100)]
tty: Fallout from tty-move-canon-specials

Today's linux-next build (x86_64 allmodconfig) failed like this:

/drivers/char/tty_ioctl.c: In function 'change_termios':
drivers/isdn/capi/capi.c:1234: error: implicit declaration of function 'n_tty_ioctl'
drivers/isdn/gigaset/ser-gigaset.c: In function 'gigaset_tty_ioctl':
drivers/isdn/gigaset/ser-gigaset.c:648: error: implicit declaration of function 'n_tty_ioctl'

Introduced by commit 686b5e4aea05a80e370dc931b7f4a8d03c80da54
("tty-move-canon-specials").  I added the following patch (which may not
be correct).

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: some ICANON magic is in the wrong places
Alan Cox [Mon, 13 Oct 2008 09:44:17 +0000 (10:44 +0100)]
tty: some ICANON magic is in the wrong places

Move the set up on ldisc change into the ldisc
Move the INQ/OUTQ cases into the driver not in shared ioctl code where it
gives bogus answers for other ldisc values

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: simplify ktermios allocation
Alan Cox [Mon, 13 Oct 2008 09:44:08 +0000 (10:44 +0100)]
tty: simplify ktermios allocation

Copy the simplification from the pty unix98 special case to the generic one.
This allows us to kill off driver->termios_locked entirely which is nice. We
have to whack bits of the cris driver as it meddles in places it shouldn't
providing its own arrays that were never used anyway.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agopty: simplify unix98 allocation
Alan Cox [Mon, 13 Oct 2008 09:43:58 +0000 (10:43 +0100)]
pty: simplify unix98 allocation

We need both termios and termios_locked so allocate them as one

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agopty: Fix allocation failure double free
Alan Cox [Mon, 13 Oct 2008 09:43:48 +0000 (10:43 +0100)]
pty: Fix allocation failure double free

The updating and moving around of the pty code added a bug where both the
helper and caller free the main tty struct (the pty driver must free the
o_tty pair itself however).

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agopty: Coding style and polish
Alan Cox [Mon, 13 Oct 2008 09:43:38 +0000 (10:43 +0100)]
pty: Coding style and polish

We've done the heavy lifting now its time to mop up a bit

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agoSimplify devpts_pty_kill
Sukadev Bhattiprolu [Mon, 13 Oct 2008 09:43:27 +0000 (10:43 +0100)]
Simplify devpts_pty_kill

When creating a new pty, save the pty's inode in the tty->driver_data.
Use this inode in pty_kill() to identify the devpts instance. Since
we now have the inode for the pty, we can skip get_node() lookup and
remove the unused get_node().

TODO:
- check if the mutex_lock is needed in pty_kill().

Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agoSimplify devpts_pty_new()
Sukadev Bhattiprolu [Mon, 13 Oct 2008 09:43:18 +0000 (10:43 +0100)]
Simplify devpts_pty_new()

devpts_pty_new() is called when setting up a new pty and would not
will not have an existing dentry or inode for the pty. So don't bother
looking for an existing dentry - just create a new one.

Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agoSimplify devpts_get_tty()
Sukadev Bhattiprolu [Mon, 13 Oct 2008 09:43:08 +0000 (10:43 +0100)]
Simplify devpts_get_tty()

As pointed out by H. Peter Anvin, since the inode for the pty is known,
we don't need to look it up.

Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agoAdd an instance parameter devpts interfaces
Sukadev Bhattiprolu [Mon, 13 Oct 2008 09:42:59 +0000 (10:42 +0100)]
Add an instance parameter devpts interfaces

Pass-in 'inode' or 'tty' parameter to devpts interfaces.  With multiple
devpts instances, these parameters will be used in subsequent patches
to identify the instance of devpts mounted. The parameters also help
simplify devpts implementation.

Changelog[v3]:
- minor changes due to merge with ttydev updates
- rename parameters to emphasize they are ptmx or pts inodes
- pass-in tty_struct * to devpts_pty_kill() (this will help
  cleanup the get_node() call in a subsequent patch)

Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agoMove tty lookup/reopen to caller
Sukadev Bhattiprolu [Mon, 13 Oct 2008 09:42:49 +0000 (10:42 +0100)]
Move tty lookup/reopen to caller

Move tty_driver_lookup_tty() and tty_reopen() from tty_init_dev()
into tty_open() (one of the two callers of tty_init_dev()).  These
calls are not really required in ptmx_open(), the other caller,
since ptmx_open() would be setting up a new tty.

Changelog[v2]:
- remove the lookup and reopen calls from ptmx_open
- merge with recent changes to ttydev tree

Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: extract the pty init time special cases
Alan Cox [Mon, 13 Oct 2008 09:42:39 +0000 (10:42 +0100)]
tty: extract the pty init time special cases

The majority of the remaining init_dev code is pty special cases. We
refactor this code into the driver->install method.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: Finish fixing up the init_dev interface to use ERR_PTR
Alan Cox [Mon, 13 Oct 2008 09:42:29 +0000 (10:42 +0100)]
tty: Finish fixing up the init_dev interface to use ERR_PTR

Original suggestion and proposal from Sukadev Bhattiprolu.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: More driver operations
Alan Cox [Mon, 13 Oct 2008 09:42:19 +0000 (10:42 +0100)]
tty: More driver operations

We have the lookup operation abstracted which is nice for pty cleanup but
we really want to abstract the add/remove entries as well so that we can
pull the pty code out of the tty core and create a clear defined interface
for the tty driver table.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: kref the tty driver object
Alan Cox [Mon, 13 Oct 2008 09:42:09 +0000 (10:42 +0100)]
tty: kref the tty driver object

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: Clean up the tty_init_dev changes further
Alan Cox [Mon, 13 Oct 2008 09:42:00 +0000 (10:42 +0100)]
tty: Clean up the tty_init_dev changes further

Fix up the naming, style and extract some bits of code into the driver
specific code

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: Move parts of tty_init_dev into new functions
Sukadev Bhattiprolu [Mon, 13 Oct 2008 09:41:51 +0000 (10:41 +0100)]
tty: Move parts of tty_init_dev into new functions

Move the 'find-tty' and 'fast-track-open' parts of init_dev() to
separate functions.

Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: Remove more special casing and out of place code
Alan Cox [Mon, 13 Oct 2008 09:41:42 +0000 (10:41 +0100)]
tty: Remove more special casing and out of place code

Carry on pushing code out of tty_io when it belongs to other drivers. I'm
not 100% happy with some of this and it will be worth revisiting some of the
exports later when the restructuring work is done.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: shutdown method
Alan Cox [Mon, 13 Oct 2008 09:41:30 +0000 (10:41 +0100)]
tty: shutdown method

Right now there are various drivers that try to use tty->count to know when
they get the final close. Aristeau Rozanski showed while debugging the vt
sysfs race that this isn't entirely safe.

Instead of driver side tricks to work around this introduce a shutdown which
is called when the tty is being destructed. This also means that the shutdown
method is tied into the refcounting.

Use this to rework the console close/sysfs logic.

Remove lots of special case code from the tty core code. The pty code can now
have a shutdown() method that replaces the special case hackery in the tree
free up paths.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agovt: remove bogus lock dropping
Alan Cox [Mon, 13 Oct 2008 09:41:16 +0000 (10:41 +0100)]
vt: remove bogus lock dropping

For hysterical raisins the vt layer drops and retakes locks in the write
method. This is a left over from the days when user/kernel data was passed
directly to the tty not pre-buffered.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agopty: If the administrator creates a device for a ptmx slave we should not error
Alan Cox [Mon, 13 Oct 2008 09:41:03 +0000 (10:41 +0100)]
pty: If the administrator creates a device for a ptmx slave we should not error

The open path for ptmx slaves is via the ptmx device. Opening them any
other way is not allowed. Vegard Nossum found that previously this was not
the case and mknod foo c 128 42; cat foo would produce nasty diagnostics

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: Fix abusers of current->sighand->tty
Alan Cox [Mon, 13 Oct 2008 09:40:53 +0000 (10:40 +0100)]
tty: Fix abusers of current->sighand->tty

Various people outside the tty layer still stick their noses in behind the
scenes. We need to make sure they also obey the locking and referencing rules.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: Redo current tty locking
Alan Cox [Mon, 13 Oct 2008 09:40:43 +0000 (10:40 +0100)]
tty: Redo current tty locking

Currently it is sometimes locked by the tty mutex and sometimes by the
sighand lock. The latter is in fact correct and now we can hand back referenced
objects we can fix this up without problems around sleeping functions.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: the vhangup syscall is racy
Alan Cox [Mon, 13 Oct 2008 09:40:30 +0000 (10:40 +0100)]
tty: the vhangup syscall is racy

We now have the infrastructure to sort this out but rather than teaching
the syscall tty lock rules we move the hard work into a tty helper

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agomxser: Switch to kref tty
Alan Cox [Mon, 13 Oct 2008 09:40:19 +0000 (10:40 +0100)]
mxser: Switch to kref tty

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agostallion: Use krefs
Alan Cox [Mon, 13 Oct 2008 09:40:07 +0000 (10:40 +0100)]
stallion: Use krefs

Use tty_port_init and krefs in the stallion drivers to protect us from devices
going away underneath us. As with the other drives some rearranging is done to
pass the tty structure down properly on the user side.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: kref usage for isicom and moxa
Alan Cox [Mon, 13 Oct 2008 09:39:58 +0000 (10:39 +0100)]
tty: kref usage for isicom and moxa

Rather than blindly keep taking krefs we reorder the code in a few places
to pass the tty down to the right place (which is important as from the user
side it is not the case that tty == port->tty in all situations). For the irq
and related paths use the krefs to stop the tty being freed under us.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: usb-serial krefs
Alan Cox [Mon, 13 Oct 2008 09:39:46 +0000 (10:39 +0100)]
tty: usb-serial krefs

Use kref in the USB serial drivers so that we don't free tty structures
from under the URB receive handlers as has historically been the case if
you were unlucky. This also gives us a framework for general tty drivers to
use tty_port objects and refcount.

Contains two err->dev_err changes merged together to fix clashes in the
-next tree.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: Move tty_write_message out of kernel/printk
Alan Cox [Mon, 13 Oct 2008 09:39:23 +0000 (10:39 +0100)]
tty: Move tty_write_message out of kernel/printk

This is pure tty code so put it in the tty layer where it can be with the
locking relevant material it uses

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: Make get_current_tty use a kref
Alan Cox [Mon, 13 Oct 2008 09:39:13 +0000 (10:39 +0100)]
tty: Make get_current_tty use a kref

We now return a kref covered tty reference. That ensures the tty structure
doesn't go away when you have a return from get_current_tty. This is not
enough to protect you from most of the resources being freed behind your
back - yet.

[Updated to include fixes for SELinux problems found by Andrew Morton and
 an s390 leak found while debugging the former]

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: compare the tty winsize
Alan Cox [Mon, 13 Oct 2008 09:39:01 +0000 (10:39 +0100)]
tty: compare the tty winsize

We always use the real tty one for stuff so the pty one should not be
compared. As we propagate window changes to both it doesn't currently
matter but will when we tidy up the pty termios logic a bit more

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: Termios locking - sort out real_tty confusions and lock reads
Alan Cox [Mon, 13 Oct 2008 09:38:46 +0000 (10:38 +0100)]
tty: Termios locking - sort out real_tty confusions and lock reads

This moves us towards sanity and should mean our termios locking is now
complete and comprehensive.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: Add termiox
Alan Cox [Mon, 13 Oct 2008 09:38:18 +0000 (10:38 +0100)]
tty: Add termiox

We need a way to describe the various additional modes and flow control
features that random weird hardware shows up and software such as wine
wants to emulate as Windows supports them.

TCGETX/TCSETX and the termiox ioctl are a SYS5 extension that we might as
well adopt. This patches adds the structures and the basic ioctl interfaces
when the TCGETX etc defines are added for an architecture. Drivers wishing
to use this stuff need to add new methods.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: ipw need reworking
Alan Cox [Mon, 13 Oct 2008 09:38:07 +0000 (10:38 +0100)]
tty: ipw need reworking

This came in via another tree and unfortunately is rather broken on
the tty side. Comment the apparent locking problems for someone who knows
the driver to look at.

Fix the termios and other ioctl handling. The driver was calling the wrong
methods for what it wanted to do but the right ones existed so its a simple
fix up.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: Cris has a nice RS485 ioctl so we should steal it
Alan Cox [Mon, 13 Oct 2008 09:37:48 +0000 (10:37 +0100)]
tty: Cris has a nice RS485 ioctl so we should steal it

JP Tosoni observed:

"About a RS485 ioctl: could you consider the attached files which are
 already in the Linux kernel (in include/asm-cris).  They define a
 TIOCSERSETRS485 (ioctl.h), and the data structure (rs485.h)
 with allows to specify timings. Sounds just like what we want ?"

and he's right: sort of. Rework the structure to use flag bits and make the
time delay a fixed sized field so we don't get 32/64bit problems. Add the ioctls
to x86 so that people know what to add to their platform of choice.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: use krefs to protect driver module counts
Alan Cox [Mon, 13 Oct 2008 09:37:36 +0000 (10:37 +0100)]
tty: use krefs to protect driver module counts

The tty layer keeps driver module counts that are used so the driver knows
when it can be unloaded. For obvious reasons we want to tie that to the
refcounting properly.

At this point the driver side itself isn't refcounted nicely but we can do
that later and kref the drivers.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: Add a kref count
Alan Cox [Mon, 13 Oct 2008 09:37:26 +0000 (10:37 +0100)]
tty: Add a kref count

Introduce a kref to the tty structure and use it to protect the tty->signal
tty references. For now we don't introduce it for anything else.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agopps: Reserve a line discipline number for PPS
Alan Cox [Mon, 13 Oct 2008 09:37:17 +0000 (10:37 +0100)]
pps: Reserve a line discipline number for PPS

Add a new line discipline for "pulse per second" devices connected to
a serial port.

Signed-off-by: Rodolfo Giometti <giometti@linux.it>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: Split tty_port into its own file
Alan Cox [Mon, 13 Oct 2008 09:37:07 +0000 (10:37 +0100)]
tty: Split tty_port into its own file

Not much in it yet but this will grow a lot

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: split the buffering from tty_io
Alan Cox [Mon, 13 Oct 2008 09:36:58 +0000 (10:36 +0100)]
tty: split the buffering from tty_io

The two are basically independent chunks of code so lets split them up for
readability and sanity. It also makes the API boundaries much clearer.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agouml: small cleanups and note bugs to be dealt with by uml authors...
Alan Cox [Mon, 13 Oct 2008 09:36:49 +0000 (10:36 +0100)]
uml: small cleanups and note bugs to be dealt with by uml authors...

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agotty: move tioclinux from a special case
Alan Cox [Mon, 13 Oct 2008 09:36:40 +0000 (10:36 +0100)]
tty: move tioclinux from a special case

Right now we have ifdefs and hooks in the core ioctl handler for TIOCLINUX
and then test if its a console. This is brain dead. Instead call the
tioclinux helper from the relevant driver ioctl methods.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agoserial: allow 8250 to be used on sparc
David Miller [Mon, 13 Oct 2008 09:36:31 +0000 (10:36 +0100)]
serial: allow 8250 to be used on sparc

This requires three changes:

1) Remove !SPARC restriction in Kconfig.

2) Move Sparc specific serial drivers before 8250, so that serial
   console devices don't change names on us, even if 8250 finds
   devices.

3) Since the Sparc specific serial drivers try to use the
   same major/minor device namespace as 8250, some coordination
   is necessary.  Use the sunserial_*() layer routines to allocate
   minor number space within TTY_MAJOR when CONFIG_SPARC.

   This has no effect on other platforms.

Thanks to Josip Rodin for bringing up this issue and testing
plus debugging various revisions of this patch.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years ago8250: remove a few inlines of dubious value
Will Newton [Mon, 13 Oct 2008 09:36:21 +0000 (10:36 +0100)]
8250: remove a few inlines of dubious value

Remove some inlines from various functions that are called once, are too
big to inline, or are called only from slow path code.  This saves around
300 bytes of code for me.

Signed-off-by: Will Newton <will.newton@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agoserial_8250: pci_enable_device fail is not fully handled
Alan Cox [Mon, 13 Oct 2008 09:36:11 +0000 (10:36 +0100)]
serial_8250: pci_enable_device fail is not fully handled

<rmk> talking about leaks - I noticed that the 'check return of
pci_enable_dev()' in the 8250 pci resume function finally made it in
despite my objections against it (causing stuff in higher levels to
leak).

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agoftdi: A few errors are err() that should be debug which causes much spewage
Alan Cox [Mon, 13 Oct 2008 09:36:00 +0000 (10:36 +0100)]
ftdi: A few errors are err() that should be debug which causes much spewage

Fixes #10783

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agousb: fix pl2303 initialization
Jason Wessel [Mon, 13 Oct 2008 09:35:51 +0000 (10:35 +0100)]
usb: fix pl2303 initialization

This patch removes the private check for the termios_initialized for
the pl2303 usb driver.  It forced the baud to 9600 on the first call
to pl2303_set_termios()

Based on the tty changes in the 2.6.27 kernel, the termios passed to
the *_set_termios functions is always populated the first time.

This means there is no need to privately initialize the settings the
first time, and doing so will not allow the use of the kernel
parameter "console=ttyUSB0,115200" as an example.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agoserial-make-uart_ports-ioport-unsigned-long-fix
Andrew Morton [Mon, 13 Oct 2008 09:35:42 +0000 (10:35 +0100)]
serial-make-uart_ports-ioport-unsigned-long-fix

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agonozomi: Fix close on error
Alan Cox [Mon, 13 Oct 2008 09:35:33 +0000 (10:35 +0100)]
nozomi: Fix close on error

Nozomi assumes the close method isn't called if open errors. The tty layer
is different to other drives in this respect however. Pointed out by Denis J
Barrow.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agoserial: Make uart_port's ioport "unsigned long".
David Miller [Mon, 13 Oct 2008 09:35:23 +0000 (10:35 +0100)]
serial: Make uart_port's ioport "unsigned long".

Otherwise the top 32-bits of the resource value get chopped
off on 64-bit systems, and the resulting I/O accesses go to
random places.

Thanks to testing and debugging by Josip Rodin, which helped
track this down.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agoaudit: Handle embedded NUL in TTY input auditing
Miloslav Trmac [Mon, 13 Oct 2008 09:35:15 +0000 (10:35 +0100)]
audit: Handle embedded NUL in TTY input auditing

Data read from a TTY can contain an embedded NUL byte (e.g. after
pressing Ctrl-2, or sent to a PTY).  After the previous patch, the data
would be logged only up to the first NUL.

This patch modifies the AUDIT_TTY record to always use the hexadecimal
format, which does not terminate at the first NUL byte.  The vast
majority of recorded TTY input data will contain either ' ' or '\n', so
the hexadecimal format would have been used anyway.

Signed-off-by: Miloslav Trmac <mitr@redhat.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agoip2: avoid add_timer with pending timer
Akinobu Mita [Mon, 13 Oct 2008 09:35:05 +0000 (10:35 +0100)]
ip2: avoid add_timer with pending timer

add_timer() is not supposed to be called when the timer is pending.
ip2 driver attempts to avoid that condition by setting and resetting
a flag (TimerOn) in timer function. But there is some gap between
add_timer() and setting TimerOn.

This patch fix this problem by using mod_timer() and remove TimerOn
which has been unnecessary by this change.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agoip2: init/deinit cleanup
Jiri Slaby [Mon, 13 Oct 2008 09:34:56 +0000 (10:34 +0100)]
ip2: init/deinit cleanup

Cleanup of module_init/exit:
- mostly whitespace
- remove empty functions
- replace c++ comments
- remove useless prints (module loaded, unloaded)
- mark the calls as __exit and __init
- use break; and return; to save some indent levels after it
- note resource leakage

It's still mess, but now it's readable.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agoip2: fix sparse warnings
Jiri Slaby [Mon, 13 Oct 2008 09:34:45 +0000 (10:34 +0100)]
ip2: fix sparse warnings

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agoip2: cleanup globals
Jiri Slaby [Mon, 13 Oct 2008 09:34:36 +0000 (10:34 +0100)]
ip2: cleanup globals

- do not init .bss zeroed data to zero again (by memset or
  explicit assignment)
- use char [] instead of char * for string constants

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agoChar: merge ip2main and ip2base
Jiri Slaby [Mon, 13 Oct 2008 09:34:27 +0000 (10:34 +0100)]
Char: merge ip2main and ip2base

It's pretty useless to have one setup() function separated along with
module_init() which only calls a function from ip2main anyway. Get rid
of ip2base.

Remove also checks of always-true now.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agoChar: sx, fix io unmapping
Jiri Slaby [Mon, 13 Oct 2008 09:34:18 +0000 (10:34 +0100)]
Char: sx, fix io unmapping

board->base is increased for CF cards after mapping. Use board->base2
for unmapping the region, since it holds the original/correct address.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agoChar: cyclades. remove bogus iomap
Jiri Slaby [Mon, 13 Oct 2008 09:34:09 +0000 (10:34 +0100)]
Char: cyclades. remove bogus iomap

readl/writel are not expected to accept iomap return value. Replace
bogus mapping by standard ioremap.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agoFix oti6858 debug level
Scott Ashcroft [Mon, 13 Oct 2008 09:34:00 +0000 (10:34 +0100)]
Fix oti6858 debug level

For some reason the oti6858 driver undefines and redefines the dbg
macro. This makes it spew debugging messages at KERN_INFO instead of
KERN_DEBUG.

This patch removes the undef and define making the driver log like every
other USB serial driver.

Signed-off-by: Scott Ashcroft <scott.ashcroft@talk21.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
16 years agoBlackfin Serial Driver: Fix bug - request UART2/3 peripheral mapped interrupts in...
Sonic Zhang [Mon, 13 Oct 2008 09:33:51 +0000 (10:33 +0100)]
Blackfin Serial Driver: Fix bug - request UART2/3 peripheral mapped interrupts in PIO mode

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>