Commit Graph

300 Commits

Author SHA1 Message Date
Linus Torvalds
b840d79631 Merge branch 'cpus4096-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'cpus4096-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (66 commits)
  x86: export vector_used_by_percpu_irq
  x86: use logical apicid in x2apic_cluster's x2apic_cpu_mask_to_apicid_and()
  sched: nominate preferred wakeup cpu, fix
  x86: fix lguest used_vectors breakage, -v2
  x86: fix warning in arch/x86/kernel/io_apic.c
  sched: fix warning in kernel/sched.c
  sched: move test_sd_parent() to an SMP section of sched.h
  sched: add SD_BALANCE_NEWIDLE at MC and CPU level for sched_mc>0
  sched: activate active load balancing in new idle cpus
  sched: bias task wakeups to preferred semi-idle packages
  sched: nominate preferred wakeup cpu
  sched: favour lower logical cpu number for sched_mc balance
  sched: framework for sched_mc/smt_power_savings=N
  sched: convert BALANCE_FOR_xx_POWER to inline functions
  x86: use possible_cpus=NUM to extend the possible cpus allowed
  x86: fix cpu_mask_to_apicid_and to include cpu_online_mask
  x86: update io_apic.c to the new cpumask code
  x86: Introduce topology_core_cpumask()/topology_thread_cpumask()
  x86: xen: use smp_call_function_many()
  x86: use work_on_cpu in x86/kernel/cpu/mcheck/mce_amd_64.c
  ...

Fixed up trivial conflict in kernel/time/tick-sched.c manually
2009-01-02 11:44:09 -08:00
Linus Torvalds
179475a3b4 Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, sparseirq: clean up Kconfig entry
  x86: turn CONFIG_SPARSE_IRQ off by default
  sparseirq: fix numa_migrate_irq_desc dependency and comments
  sparseirq: add kernel-doc notation for new member in irq_desc, -v2
  locking, irq: enclose irq_desc_lock_class in CONFIG_LOCKDEP
  sparseirq, xen: make sure irq_desc is allocated for interrupts
  sparseirq: fix !SMP building, #2
  x86, sparseirq: move irq_desc according to smp_affinity, v7
  proc: enclose desc variable of show_stat() in CONFIG_SPARSE_IRQ
  sparse irqs: add irqnr.h to the user headers list
  sparse irqs: handle !GENIRQ platforms
  sparseirq: fix !SMP && !PCI_MSI && !HT_IRQ build
  sparseirq: fix Alpha build failure
  sparseirq: fix typo in !CONFIG_IO_APIC case
  x86, MSI: pass irq_cfg and irq_desc
  x86: MSI start irq numbering from nr_irqs_gsi
  x86: use NR_IRQS_LEGACY
  sparse irq_desc[] array: core kernel and x86 changes
  genirq: record IRQ_LEVEL in irq_desc[]
  irq.h: remove padding from irq_desc on 64bits
2008-12-30 16:20:19 -08:00
Linus Torvalds
bb758e9637 Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  hrtimers: fix warning in kernel/hrtimer.c
  x86: make sure we really have an hpet mapping before using it
  x86: enable HPET on Fujitsu u9200
  linux/timex.h: cleanup for userspace
  posix-timers: simplify de_thread()->exit_itimers() path
  posix-timers: check ->it_signal instead of ->it_pid to validate the timer
  posix-timers: use "struct pid*" instead of "struct task_struct*"
  nohz: suppress needless timer reprogramming
  clocksource, acpi_pm.c: put acpi_pm_read_slow() under CONFIG_PCI
  nohz: no softirq pending warnings for offline cpus
  hrtimer: removing all ur callback modes, fix
  hrtimer: removing all ur callback modes, fix hotplug
  hrtimer: removing all ur callback modes
  x86: correct link to HPET timer specification
  rtc-cmos: export second NVRAM bank

Fixed up conflicts in sound/drivers/pcsp/pcsp.c and sound/core/hrtimer.c
manually.
2008-12-30 16:16:21 -08:00
Linus Torvalds
a39b863342 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (31 commits)
  sched: fix warning in fs/proc/base.c
  schedstat: consolidate per-task cpu runtime stats
  sched: use RCU variant of list traversal in for_each_leaf_rt_rq()
  sched, cpuacct: export percpu cpuacct cgroup stats
  sched, cpuacct: refactoring cpuusage_read / cpuusage_write
  sched: optimize update_curr()
  sched: fix wakeup preemption clock
  sched: add missing arch_update_cpu_topology() call
  sched: let arch_update_cpu_topology indicate if topology changed
  sched: idle_balance() does not call load_balance_newidle()
  sched: fix sd_parent_degenerate on non-numa smp machine
  sched: add uid information to sched_debug for CONFIG_USER_SCHED
  sched: move double_unlock_balance() higher
  sched: update comment for move_task_off_dead_cpu
  sched: fix inconsistency when redistribute per-cpu tg->cfs_rq shares
  sched/rt: removed unneeded defintion
  sched: add hierarchical accounting to cpu accounting controller
  sched: include group statistics in /proc/sched_debug
  sched: rename SCHED_NO_NO_OMIT_FRAME_POINTER => SCHED_OMIT_FRAME_POINTER
  sched: clean up SCHED_CPUMASK_ALLOC
  ...
2008-12-28 12:27:58 -08:00
Linus Torvalds
b0f4b285d7 Merge branch 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (241 commits)
  sched, trace: update trace_sched_wakeup()
  tracing/ftrace: don't trace on early stage of a secondary cpu boot, v3
  Revert "x86: disable X86_PTRACE_BTS"
  ring-buffer: prevent false positive warning
  ring-buffer: fix dangling commit race
  ftrace: enable format arguments checking
  x86, bts: memory accounting
  x86, bts: add fork and exit handling
  ftrace: introduce tracing_reset_online_cpus() helper
  tracing: fix warnings in kernel/trace/trace_sched_switch.c
  tracing: fix warning in kernel/trace/trace.c
  tracing/ring-buffer: remove unused ring_buffer size
  trace: fix task state printout
  ftrace: add not to regex on filtering functions
  trace: better use of stack_trace_enabled for boot up code
  trace: add a way to enable or disable the stack tracer
  x86: entry_64 - introduce FTRACE_ frame macro v2
  tracing/ftrace: add the printk-msg-only option
  tracing/ftrace: use preempt_enable_no_resched_notrace in ring_buffer_time_stamp()
  x86, bts: correctly report invalid bts records
  ...

Fixed up trivial conflict in scripts/recordmcount.pl due to SH bits
being already partly merged by the SH merge.
2008-12-28 12:21:10 -08:00
Ingo Molnar
973656fe1a x86, sparseirq: clean up Kconfig entry
Impact: improve help text

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-25 16:26:47 +01:00
Ingo Molnar
4e17fee24a x86: turn CONFIG_SPARSE_IRQ off by default
New feature - lets disable it by default first - can flip it around
later.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-25 12:04:17 +01:00
Ingo Molnar
3e5621edb3 Merge branch 'x86/iommu' into x86/core 2008-12-23 16:30:27 +01:00
Ingo Molnar
fa623d1b02 Merge branches 'x86/apic', 'x86/cleanups', 'x86/cpufeature', 'x86/crashdump', 'x86/debug', 'x86/defconfig', 'x86/detect-hyper', 'x86/doc', 'x86/dumpstack', 'x86/early-printk', 'x86/fpu', 'x86/idle', 'x86/io', 'x86/memory-corruption-check', 'x86/microcode', 'x86/mm', 'x86/mtrr', 'x86/nmi-watchdog', 'x86/pat2', 'x86/pci-ioapic-boot-irq-quirks', 'x86/ptrace', 'x86/quirks', 'x86/reboot', 'x86/setup-memory', 'x86/signal', 'x86/sparse-fixes', 'x86/time', 'x86/uv' and 'x86/xen' into x86/core 2008-12-23 16:27:23 +01:00
Yinghai Lu
b909895739 sparseirq: fix numa_migrate_irq_desc dependency and comments
Impact: reduce kconfig variable scope and clean up

Bartlomiej pointed out that the config dependencies and comments are not right.

update it depend to NUMA, and fix some comments

Reported-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-19 22:56:02 +01:00
Ingo Molnar
948a7b2b5e Merge branch 'irq/sparseirq' into cpus4096
Conflicts:
	arch/x86/kernel/io_apic.c

Merge irq/sparseirq here, to resolve conflicts.
2008-12-17 13:16:08 +01:00
Mike Travis
78637a97b7 x86: Set CONFIG_NR_CPUS even on UP
Impact: cleanup

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
2008-12-16 17:40:58 -08:00
Mike Travis
36f5101a60 x86: enable MAXSMP
Impact: activates new off-stack cpumask code on MAXSMP (non-default) x86 configs

Set MAXSMP to enable CONFIG_CPUMASK_OFFSTACK which moves cpumask's off
the stack (and in structs) when using cpumask_var_t.

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Ingo Molnar <mingo@elte.hy>
2008-12-16 17:40:55 -08:00
Yinghai Lu
17483a1f34 sparseirq: fix !SMP building, #2
Impact: build fix

make intr_remapping.c to include smp.h, so could use boot_cpu_id there

also remove old change that disabling sparseirq with !SMP

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-17 00:15:55 +01:00
Yinghai Lu
48a1b10aff x86, sparseirq: move irq_desc according to smp_affinity, v7
Impact: improve NUMA handling by migrating irq_desc on smp_affinity changes

if CONFIG_NUMA_MIGRATE_IRQ_DESC is set:

-  make irq_desc to go with affinity aka irq_desc moving etc
-  call move_irq_desc in irq_complete_move()
-  legacy irq_desc is not moved, because they are allocated via static array

for logical apic mode, need to add move_desc_in_progress_in_same_domain,
otherwise it will not be moved ==> also could need two phases to get
irq_desc moved.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-17 00:14:01 +01:00
Ingo Molnar
78f902ccc5 Merge commit 'v2.6.28-rc8' into x86/doc 2008-12-16 22:04:48 +01:00
Jan Beulich
b93a531e31 allow bug table entries to use relative pointers (and use it on x86-64)
Impact: reduce bug table size

This allows reducing the bug table size by half. Perhaps there are
other 64-bit architectures that could also make use of this.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-16 18:40:32 +01:00
Ingo Molnar
8299608f14 Merge branches 'irq/sparseirq', 'x86/quirks' and 'x86/reboot' into cpus4096
We merge the irq/sparseirq, x86/quirks and x86/reboot trees into the
cpus4096 tree because the io-apic changes in the sparseirq change
conflict with the cpumask changes in the cpumask tree, and we
want to resolve those.
2008-12-12 13:49:24 +01:00
Ingo Molnar
81444a7995 Merge branch 'tracing/fastboot' into cpus4096 2008-12-12 12:43:05 +01:00
Ingo Molnar
e18d7af852 Merge commit 'v2.6.28-rc8' into x86/mm 2008-12-12 11:53:43 +01:00
Yinghai Lu
8a4830f889 sparseirq: fix !SMP && !PCI_MSI && !HT_IRQ build
Ingo Molnar wrote:

>>>  drivers/pci/intr_remapping.c: In function 'irq_2_iommu_alloc':
>>>  drivers/pci/intr_remapping.c:72: error: 'boot_cpu_id' undeclared (first use in this function)
>>>  drivers/pci/intr_remapping.c:72: error: (Each undeclared identifier is reported only once
>>>  drivers/pci/intr_remapping.c:72: error: for each function it appears in.)

sparseirq should only be used with SMP for now.
2008-12-09 21:02:19 +01:00
Ingo Molnar
aa9c9b8c58 Merge branch 'linus' into x86/quirks 2008-12-08 15:07:49 +01:00
Yinghai Lu
0b8f1efad3 sparse irq_desc[] array: core kernel and x86 changes
Impact: new feature

Problem on distro kernels: irq_desc[NR_IRQS] takes megabytes of RAM with
NR_CPUS set to large values. The goal is to be able to scale up to much
larger NR_IRQS value without impacting the (important) common case.

To solve this, we generalize irq_desc[NR_IRQS] to an (optional) array of
irq_desc pointers.

When CONFIG_SPARSE_IRQ=y is used, we use kzalloc_node to get irq_desc,
this also makes the IRQ descriptors NUMA-local (to the site that calls
request_irq()).

This gets rid of the irq_cfg[] static array on x86 as well: irq_cfg now
uses desc->chip_data for x86 to store irq_cfg.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-08 14:31:51 +01:00
Ingo Molnar
c0515566f3 Merge commit 'v2.6.28-rc7' into x86/cleanups 2008-12-04 11:05:26 +01:00
Ingo Molnar
6083aa485c Merge branch 'x86/io' into x86/iommu
Merge x86/io into x86/iommu due to a small patch conflict in io.h.
2008-12-03 08:25:59 +01:00
Niels de Vos
8daa19051e x86, apm: remove CONFIG_APM_REAL_MODE_POWER_OFF in favor of a kernel parameter
Remove CONFIG_APM_REAL_MODE_POWER_OFF like CONFIG_APM_POWER_OFF which
has been done for linux-2.2.14pre8 (http://lkml.org/lkml/1999/11/23/3).

Re-introducing CONFIG_APM_POWER_OFF got nack-ed. Stephen didn't bother
to remove CONFIG_APM_REAL_MODE_POWER_OFF, let's get rid of it now.
	Reference: http://lkml.org/lkml/2008/5/7/97

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-02 11:28:49 +01:00
Frederic Weisbecker
48d68b20d0 tracing/function-graph-tracer: support for x86-64
Impact: extend and enable the function graph tracer to 64-bit x86

This patch implements the support for function graph tracer under x86-64.
Both static and dynamic tracing are supported.

This causes some small CPP conditional asm on arch/x86/kernel/ftrace.c I
wanted to use probe_kernel_read/write to make the return address
saving/patching code more generic but it causes tracing recursion.

That would be perhaps useful to implement a notrace version of these
function for other archs ports.

Note that arch/x86/process_64.c is not traced, as in X86-32. I first
thought __switch_to() was responsible of crashes during tracing because I
believed current task were changed inside but that's actually not the
case (actually yes, but not the "current" pointer).

So I will have to investigate to find the functions that harm here, to
enable tracing of the other functions inside (but there is no issue at
this time, while process_64.c stays out of -pg flags).

A little possible race condition is fixed inside this patch too. When the
tracer allocate a return stack dynamically, the current depth is not
initialized before but after. An interrupt could occur at this time and,
after seeing that the return stack is allocated, the tracer could try to
trace it with a random uninitialized depth. It's a prevention, even if I
hadn't problems with it.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tim Bird <tim.bird@am.sony.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-02 09:47:48 +01:00
Ingo Molnar
f6d2e6f57b Merge branch 'x86/urgent' into x86/iommu 2008-12-01 20:36:13 +01:00
Hitoshi Mitake
2c5643b1c5 x86: provide readq()/writeq() on 32-bit too
Impact: add new API for drivers

Add implementation of readq/writeq to x86_32, and add config value to
the x86 architecture to determine existence of readq/writeq.

Signed-off-by: Hitoshi Mitake <h.mitake@gmail.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-30 09:38:16 +01:00
Frederic Weisbecker
fb52607afc tracing/function-return-tracer: change the name into function-graph-tracer
Impact: cleanup

This patch changes the name of the "return function tracer" into
function-graph-tracer which is a more suitable name for a tracing
which makes one able to retrieve the ordered call stack during
the code flow.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-26 01:59:45 +01:00
Ingo Molnar
943f3d0300 Merge branches 'sched/core', 'core/core' and 'tracing/core' into cpus4096 2008-11-24 17:46:57 +01:00
Denis V. Lunev
e45f2c0774 x86: correct link to HPET timer specification
Impact: update documentation / help text

Original link is dead.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-24 10:05:12 +01:00
Török Edwin
8d26487fd4 tracing/stack-tracer: introduce CONFIG_USER_STACKTRACE_SUPPORT
Impact: cleanup

User stack tracing is just implemented for x86, but it is not x86 specific.

Introduce a generic config flag, that is currently enabled only for x86.
When other arches implement it, they will have to
SELECT USER_STACKTRACE_SUPPORT.

Signed-off-by: Török Edwin <edwintorok@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-23 11:53:50 +01:00
Ingo Molnar
a0a70c735e Merge branches 'tracing/profiling', 'tracing/options' and 'tracing/urgent' into tracing/core 2008-11-23 09:10:32 +01:00
Ingo Molnar
fc02e90c34 Merge commit 'v2.6.28-rc6' into sched/core 2008-11-21 08:57:04 +01:00
Linus Torvalds
3108864e2d Merge branch 'x86/numa' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86/numa' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: make NUMA on 32-bit depend on EXPERIMENTAL again
  x86, hibernate: fix breakage on x86_32 with CONFIG_NUMA set
2008-11-19 18:53:02 -08:00
Ingo Molnar
3ac3ba0b39 Merge branch 'linus' into sched/core
Conflicts:
	kernel/Makefile
2008-11-19 09:44:37 +01:00
Yinghai Lu
b5fe363b7d x86: use update_genapic to get rid of ES7000_CLUSTERED_APIC v2
Impact: clean up

We can autodetect those system that need cluster apic, and update genapic
accordingly.

We can also remove wakeup.h for e7000, because it's default one is now
the same as overall default mach_wakecpu.h

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-18 17:35:40 +01:00
Ingo Molnar
73f56c0d35 Merge branch 'iommu-fixes-2.6.28' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/linux-2.6-iommu into x86/urgent 2008-11-18 16:48:49 +01:00
Ingo Molnar
cbe9ee00ce Merge branch 'x86/urgent' into x86/cleanups 2008-11-18 15:41:36 +01:00
Joerg Roedel
a1afd01c17 x86: default to SWIOTLB=y on x86_64
Impact: fixes korg bugzilla 11980

A kernel for a 64bit x86 system should always contain the swiotlb code
in case it is booted on a machine without any hardware IOMMU supported
by the kernel and more than 4GB of RAM. This patch changes Kconfig to
always compile swiotlb into the kernel for x86_64.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Cc: stable@kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-18 14:52:46 +01:00
Ingo Molnar
9dacc71ff3 Merge commit 'v2.6.28-rc5' into x86/cleanups 2008-11-17 10:46:18 +01:00
Rafael J. Wysocki
604d205548 x86: make NUMA on 32-bit depend on EXPERIMENTAL again
My previous patch to make CONFIG_NUMA on x86_32 depend on BROKEN
turned out to be unnecessary, after all, since the source of the
hibernation vs CONFIG_NUMA problem turned out to be the fact that
we didn't take the NUMA KVA remapping into account in the
hibernation code.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-12 23:28:52 +01:00
Ingo Molnar
60a011c736 Merge branch 'tracing/function-return-tracer' into tracing/fastboot 2008-11-12 10:17:09 +01:00
Ingo Molnar
d06bbd6695 Merge branches 'tracing/ftrace' and 'tracing/urgent' into tracing/core
Conflicts:
	kernel/trace/ring_buffer.c
2008-11-12 10:11:37 +01:00
Ingo Molnar
c280ea5e4c x86: fix documentation typo in arch/x86/Kconfig
Impact: documentation update

Chris Snook pointed out that it's Core i7, not Core 7i.

Reported-by: Chris Snook <csnook@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-11 19:30:29 +01:00
James Bottomley
6cd10f8db3 x86, voyager: fix smp generic helper voyager breakage
Impact: build/boot fix for x86/Voyager

This change:

| commit 3d44223327
| Author: Jens Axboe <jens.axboe@oracle.com>
| Date:   Thu Jun 26 11:21:34 2008 +0200
|
|     Add generic helpers for arch IPI function calls

didn't wire up the voyager smp call function correctly, so do that
here.  Also make CONFIG_USE_GENERIC_SMP_HELPERS a def_bool y again,
since we now use the generic helpers for every x86 architecture.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jens Axboe <Jens.Axboe@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-11 12:08:53 +01:00
Ingo Molnar
f1c4be5eda tracing, x86: clean up FUNCTION_RET_TRACER Kconfig
Impact: cleanup

move FUNCTION_RET_TRACER to the X86 select section, where we have all the
other options.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-11 10:29:17 +01:00
Frederic Weisbecker
caf4b323b0 tracing, x86: add low level support for ftrace return tracing
Impact: add infrastructure for function-return tracing

Add low level support for ftrace return tracing.

This plug-in stores return addresses on the thread_info structure of
the current task.

The index of the current return address is initialized when the task
is the first one (init) and when a process forks (the child). It is
not needed when a task does a sys_execve because after this syscall,
it still needs to return on the kernel functions it called.

Note that the code of return_to_handler has been suggested by Steven
Rostedt as almost all of the ideas of improvements in this V3.

For purpose of security, arch/x86/kernel/process_32.c is not traced
because __switch_to() changes the current task during its execution.
That could cause inconsistency in the stored return address of this
function even if I didn't have any crash after testing with tracing on
this function enabled.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-11 10:29:11 +01:00
Ingo Molnar
e0cb4ebcd9 Merge branch 'tracing/urgent' into tracing/ftrace
Conflicts:
	kernel/trace/trace.c
2008-11-11 09:40:18 +01:00