The _XOPEN_SOURCE* defines are not really needed on Linux and
it's not like we'll port this to AIX ;-)
The define also broke the build with gcc 4.4.1:
CC util/trace-event-parse.o
In file included from util/trace-event-parse.c:32:
util/util.h:43:1: error: "_XOPEN_SOURCE" redefined
So remove them.
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This adds support for tracing callchains for powerpc, both 32-bit
and 64-bit, and both in the kernel and userspace, from PMU interrupt
context.
The first three entries stored for each callchain are the NIP (next
instruction pointer), LR (link register), and the contents of the LR
save area in the second stack frame (the first is ignored because the
ABI convention on powerpc is that functions save their return address
in their caller's stack frame). Because leaf functions don't have to
save their return address (LR value) and don't have to establish a
stack frame, it's possible for either or both of LR and the second
stack frame's LR save area to have valid return addresses in them.
This is basically impossible to disambiguate without either reading
the code or looking at auxiliary information such as CFI tables.
Since we don't want to do either of those things at interrupt time,
we store both LR and the second stack frame's LR save area.
Once we get past the second stack frame, there is no ambiguity; all
return addresses we get are reliable.
For kernel traces, we check whether they are valid kernel instruction
addresses and store zero instead if they are not (rather than
omitting them, which would make it impossible for userspace to know
which was which). We also store zero instead of the second stack
frame's LR save area value if it is the same as LR.
For kernel traces, we check for interrupt frames, and for user traces,
we check for signal frames. In each case, since we're starting a new
trace, we store a PERF_CONTEXT_KERNEL/USER marker so that userspace
knows that the next three entries are NIP, LR and the second stack frame
for the interrupted context.
We read user memory with __get_user_inatomic. On 64-bit, if this
PMU interrupt occurred while interrupts are soft-disabled, and
there is no MMU hash table entry for the page, we will get an
-EFAULT return from __get_user_inatomic even if there is a valid
Linux PTE for the page, since hash_page isn't reentrant. Thus we
have code here to read the Linux PTE and access the page via the
kernel linear mapping. Since 64-bit doesn't use (or need) highmem
there is no need to do kmap_atomic. On 32-bit, we don't do soft
interrupt disabling, so this complication doesn't occur and there
is no need to fall back to reading the Linux PTE, since hash_page
(or the TLB miss handler) will get called automatically if necessary.
Note that we cannot get PMU interrupts in the interval during
context switch between switch_mm (which switches the user address
space) and switch_to (which actually changes current to the new
process). On 64-bit this is because interrupts are hard-disabled
in switch_mm and stay hard-disabled until they are soft-enabled
later, after switch_to has returned. So there is no possibility
of trying to do a user stack trace when the user address space is
not current's address space.
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This provides a mechanism to allow the perf_counters code to access
user memory in a PMU interrupt routine. Such an access can cause
various kinds of interrupt: SLB miss, MMU hash table miss, segment
table miss, or TLB miss, depending on the processor. This commit
only deals with 64-bit classic/server processors, which use an MMU
hash table. 32-bit processors are already able to access user memory
at interrupt time. Since we don't soft-disable on 32-bit, we avoid
the possibility of reentering hash_page or the TLB miss handlers,
since they run with interrupts disabled.
On 64-bit processors, an SLB miss interrupt on a user address will
update the slb_cache and slb_cache_ptr fields in the paca. This is
OK except in the case where a PMU interrupt occurs in switch_slb,
which also accesses those fields. To prevent this, we hard-disable
interrupts in switch_slb. Interrupts are already soft-disabled at
this point, and will get hard-enabled when they get soft-enabled
later.
This also reworks slb_flush_and_rebolt: to avoid hard-disabling twice,
and to make sure that it clears the slb_cache_ptr when called from
other callers than switch_slb, the existing routine is renamed to
__slb_flush_and_rebolt, which is called by switch_slb and the new
version of slb_flush_and_rebolt.
Similarly, switch_stab (used on POWER3 and RS64 processors) gets a
hard_irq_disable() to protect the per-cpu variables used there and
in ste_allocate.
If a MMU hashtable miss interrupt occurs, normally we would call
hash_page to look up the Linux PTE for the address and create a HPTE.
However, hash_page is fairly complex and takes some locks, so to
avoid the possibility of deadlock, we check the preemption count
to see if we are in a (pseudo-)NMI handler, and if so, we don't call
hash_page but instead treat it like a bad access that will get
reported up through the exception table mechanism. An interrupt
whose handler runs even though the interrupt occurred when
soft-disabled (such as the PMU interrupt) is considered a pseudo-NMI
handler, which should use nmi_enter()/nmi_exit() rather than
irq_enter()/irq_exit().
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
On 32-bit systems with 64-bit PTEs, the PTEs have to be written in two
32-bit halves. On SMP we write the higher-order half and then the
lower-order half, with a write barrier between the two halves, but on
UP there was no particular ordering of the writes to the two halves.
This extends the ordering that we already do on SMP to the UP case as
well. The reason is that with the perf_counter subsystem potentially
accessing user memory at interrupt time to get stack traces, we have
to be careful not to create an incorrect but apparently valid PTE even
on UP.
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Librarize trace_event() helper so that perf trace can use it
too. Also clean up the debug.h includes a bit.
It's not good to have it included in perf.h because it doesn't
make it flexible against other headers it may need (headers
that can also depend on perf.h and then create a recursive
header dependency).
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <1250453149-664-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The soon coming perf trace needs to use printf with dynamically
built formats.
But we are using -Wformat=2 which is a shortcut for the
following set: -Wformat -Wformat-security -Wformat-y2k
-Wformat-nonliteral
-Wformat-nonliteral warns when it can't check formats because
they are not builtin constant strings, but we want to feature
dynamic formats. What we want instead is Wformat=2 minus
-Wformat-nonliteral, which is what this patch does.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <1250437927-25490-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Related to a shadowed variable bug fix Valdis Kletnieks noticed
that perf does not get built with -Wshadow, which could have
helped us avoid the bug.
So enable -Wshadow and also enable the following warnings on
perf builds, in addition to the already enabled -Wall -Wextra
-std=gnu99 warnings:
-Wcast-align
-Wformat=2
-Wshadow
-Winit-self
-Wpacked
-Wredundant-decls
-Wstack-protector
-Wstrict-aliasing=3
-Wswitch-default
-Wswitch-enum
-Wno-system-headers
-Wundef
-Wvolatile-register-var
-Wwrite-strings
-Wbad-function-cast
-Wmissing-declarations
-Wmissing-prototypes
-Wnested-externs
-Wold-style-definition
-Wstrict-prototypes
-Wdeclaration-after-statement
And change/fix the perf code to build cleanly under GCC 4.3.2.
The list of warnings enablement is rather arbitrary: it's based
on my (quick) reading of the GCC manpages and trying them on
perf.
I categorized the warnings based on individually enabling them
and looking whether they trigger something in the perf build.
If i liked those warnings (i.e. if they trigger for something
that arguably could be improved) i enabled the warning.
If the warnings seemed to come from language laywers spamming
the build with tons of nuisance warnings i generally kept them
off. Most of the sign conversion related warnings were in
this category. (A second patch enabling some of the sign
warnings might be welcome - sign bugs can be nasty.)
I also kept warnings that seem to make sense from their manpage
description and which produced no actual warnings on our code
base. These warnings might still be turned off if they end up
being a nuisance.
I also left out a few warnings that are not supported in older
compilers.
[ Note that these changes might break the build on older
compilers i did not test, or on non-x86 architectures that
produce different warnings, so more testing would be welcome. ]
Reported-by: Valdis.Kletnieks@vt.edu
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Conflicts:
kernel/perf_counter.c
Merge reason: update to latest upstream (-rc6) and resolve
the conflict with urgent fixes.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
We were using 'fd' locally, but there was a global 'fd' too, so
when converting from open to fopen the test made against fd
should be made against 'fp', but since we have that global
it didnt get discovered ...
Reported-by: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20090814182632.GF3490@ghostprotocols.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
free_irq() can remove an irqaction while the corresponding interrupt
is in progress, but free_irq() sets action->thread to NULL
unconditionally, which might lead to a NULL pointer dereference in
handle_IRQ_event() when the hard interrupt context tries to wake up
the handler thread.
Prevent this by moving the thread stop after synchronize_irq(). No
need to set action->thread to NULL either as action is going to be
freed anyway.
This fixes a boot crash reported against preempt-rt which uses the
mainline irq threads code to implement full irq threading.
[ tglx: removed local irqthread variable ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf_counter: Report the cloning task as parent on perf_counter_fork()
perf_counter: Fix an ipi-deadlock
perf: Rework/fix the whole read vs group stuff
perf_counter: Fix swcounter context invariance
perf report: Don't show unresolved DSOs and symbols when -S/-d is used
perf tools: Add a general option to enable raw sample records
perf tools: Add a per tracepoint counter attribute to get raw sample
perf_counter: Provide hw_perf_counter_setup_online() APIs
perf list: Fix large list output by using the pager
perf_counter, x86: Fix/improve apic fallback
perf record: Add missing -C option support for specifying profile cpu
perf tools: Fix dso__new handle() to handle deleted DSOs
perf tools: Fix fallback to cplus_demangle() when bfd_demangle() is not available
perf report: Show the tid too in -D
perf record: Fix .tid and .pid fill-in when synthesizing events
perf_counter, x86: Fix generic cache events on P6-mobile CPUs
perf_counter, x86: Fix lapic printk message
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
futex: Fix handling of bad requeue syscall pairing
futex: Fix compat_futex to be same as futex for REQUEUE_PI
locking, sched: Give waitqueue spinlocks their own lockdep classes
futex: Update futex_q lock_ptr on requeue proxy lock
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: Fix oops in identify_cpu() on CPUs without CPUID
x86: Clear incorrectly forced X86_FEATURE_LAHF_LM flag
x86, mce: therm_throt - change when we print messages
x86: Add reboot quirk for every 5 series MacBook/Pro
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2: (22 commits)
ocfs2: Fix possible deadlock when extending quota file
ocfs2: keep index within status_map[]
ocfs2: Initialize the cluster we're writing to in a non-sparse extend
ocfs2: Remove redundant BUG_ON in __dlm_queue_ast()
ocfs2/quota: Release lock for error in ocfs2_quota_write.
ocfs2: Define credit counts for quota operations
ocfs2: Remove syncjiff field from quota info
ocfs2: Fix initialization of blockcheck stats
ocfs2: Zero out padding of on disk dquot structure
ocfs2: Initialize blocks allocated to local quota file
ocfs2: Mark buffer uptodate before calling ocfs2_journal_access_dq()
ocfs2: Make global quota files blocksize aligned
ocfs2: Use ocfs2_rec_clusters in ocfs2_adjust_adjacent_records.
ocfs2: Fix deadlock on umount
ocfs2: Add extra credits and access the modified bh in update_edge_lengths.
ocfs2: Fail ocfs2_get_block() immediately when a block needs allocation
ocfs2: Fix error return in ocfs2_write_cluster()
ocfs2: Fix compilation warning for fs/ocfs2/xattr.c
ocfs2: Initialize count in aio_write before generic_write_checks
ocfs2: log the actual return value of ocfs2_file_aio_write()
...
* 'for-linus' of git://neil.brown.name/md:
md: allow upper limit for resync/reshape to be set when array is read-only
md/raid5: Properly remove excess drives after shrinking a raid5/6
md/raid5: make sure a reshape restarts at the correct address.
md/raid5: allow new reshape modes to be restarted in the middle.
md: never advance 'events' counter by more than 1.
Remove deadlock potential in md_open
* 'sh/for-2.6.31' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6:
sh: fix i2c init order on ap325rxa V2
sh: fix i2c init order on Migo-R V2
sh: convert processor device setup functions to arch_initcall()
kernel_sendpage() does the proper default case handling for when the
socket doesn't have a native sendpage implementation.
Now, arguably this might be something that we could instead solve by
just specifying that all protocols should do it themselves at the
protocol level, but we really only care about the common protocols.
Does anybody really care about sendpage on something like Appletalk? Not
likely.
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Julien TINNES <julien@cr0.org>
Acked-by: Tavis Ormandy <taviso@sdf.lonestar.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
