This patch rebase the implementation of the breakpoints API on top of
perf events instances.
Each breakpoints are now perf events that handle the
register scheduling, thread/cpu attachment, etc..
The new layering is now made as follows:
ptrace kgdb ftrace perf syscall
\ | / /
\ | / /
/
Core breakpoint API /
/
| /
| /
Breakpoints perf events
|
|
Breakpoints PMU ---- Debug Register constraints handling
(Part of core breakpoint API)
|
|
Hardware debug registers
Reasons of this rewrite:
- Use the centralized/optimized pmu registers scheduling,
implying an easier arch integration
- More powerful register handling: perf attributes (pinned/flexible
events, exclusive/non-exclusive, tunable period, etc...)
Impact:
- New perf ABI: the hardware breakpoints counters
- Ptrace breakpoints setting remains tricky and still needs some per
thread breakpoints references.
Todo (in the order):
- Support breakpoints perf counter events for perf tools (ie: implement
perf_bpcounter_event())
- Support from perf tools
Changes in v2:
- Follow the perf "event " rename
- The ptrace regression have been fixed (ptrace breakpoint perf events
weren't released when a task ended)
- Drop the struct hw_breakpoint and store generic fields in
perf_event_attr.
- Separate core and arch specific headers, drop
asm-generic/hw_breakpoint.h and create linux/hw_breakpoint.h
- Use new generic len/type for breakpoint
- Handle off case: when breakpoints api is not supported by an arch
Changes in v3:
- Fix broken CONFIG_KVM, we need to propagate the breakpoint api
changes to kvm when we exit the guest and restore the bp registers
to the host.
Changes in v4:
- Drop the hw_breakpoint_restore() stub as it is only used by KVM
- EXPORT_SYMBOL_GPL hw_breakpoint_restore() as KVM can be built as a
module
- Restore the breakpoints unconditionally on kvm guest exit:
TIF_DEBUG_THREAD doesn't anymore cover every cases of running
breakpoints and vcpu->arch.switch_db_regs might not always be
set when the guest used debug registers.
(Waiting for a reliable optimization)
Changes in v5:
- Split-up the asm-generic/hw-breakpoint.h moving to
linux/hw_breakpoint.h into a separate patch
- Optimize the breakpoints restoring while switching from kvm guest
to host. We only want to restore the state if we have active
breakpoints to the host, otherwise we don't care about messed-up
address registers.
- Add asm/hw_breakpoint.h to Kbuild
- Fix bad breakpoint type in trace_selftest.c
Changes in v6:
- Fix wrong header inclusion in trace.h (triggered a build
error with CONFIG_FTRACE_SELFTEST
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Prasad <prasad@linux.vnet.ibm.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jan Kiszka <jan.kiszka@web.de>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Paul Mundt <lethal@linux-sh.org>
SDM Vol 3a section titled "MTRR considerations in MP systems" specifies
the need for synchronizing the logical cpu's while initializing/updating
MTRR.
Currently Linux kernel does the synchronization of all cpu's only when
a single MTRR register is programmed/updated. During an AP online
(during boot/cpu-online/resume) where we initialize all the MTRR/PAT registers,
we don't follow this synchronization algorithm.
This can lead to scenarios where during a dynamic cpu online, that logical cpu
is initializing MTRR/PAT with cache disabled (cr0.cd=1) etc while other logical
HT sibling continue to run (also with cache disabled because of cr0.cd=1
on its sibling).
Starting from Westmere, VMX transitions with cr0.cd=1 don't work properly
(because of some VMX performance optimizations) and the above scenario
(with one logical cpu doing VMX activity and another logical cpu coming online)
can result in system crash.
Fix the MTRR initialization by doing rendezvous of all the cpus. During
boot and resume, we delay the MTRR/PAT init for APs till all the
logical cpu's come online and the rendezvous process at the end of AP's bringup,
will initialize the MTRR/PAT for all AP's.
For dynamic single cpu online, we synchronize all the logical cpus and
do the MTRR/PAT init on the AP that is coming online.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Patch 08687aec71bc9134fe336e561f6did877bacf74fc0a (x86: unify
power/cpu_(32|64).c) renamed cpu_32.c to cpu.c, but did not update
the special compilation flags for the file for the new name.
This patch fixes the compilation flags, and therefore fixes resume
from suspend on my Acer Aspire One.
[rjw: The regression from 2.6.30 fixed by this patch is tracked as
http://bugzilla.kernel.org/show_bug.cgi?id=13661]
Signed-off-by: Peter Chubb <peterc@nicta.com.au>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Calling mcheck_init() on resume is required only with
CONFIG_X86_OLD_MCE=y.
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
This is the last unification step. Here we do remove one of the files
and rename the left one as cpu.c, as both are now the same.
Also update power/Makefile, telling it to build cpu.o, instead of
cpu_(32|64).o
Signed-off-by: Sergio Luis <sergio@larces.uece.br>
Signed-off-by: Lauro Salmito <laurosalmito@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
In this step, we do unify the copyright notes for both files
cpu_32.c and cpu_64.c, making such files exactly the same.
It's the last step before the actual unification, that will
rename one of them to cpu.c and remove the other one.
Signed-off-by: Sergio Luis <sergio@larces.uece.br>
Signed-off-by: Lauro Salmito <laurosalmito@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
In this step we do unify cpu_32.c and cpu_64.c functions that
work on restoring the saved processor state. Also, we do
eliminate the forward declaration of fix_processor_context()
for X86_64, as it's not needed anymore.
Signed-off-by: Sergio Luis <sergio@larces.uece.br>
Signed-off-by: Lauro Salmito <laurosalmito@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
In this step we do unify cpu_32.c and cpu_64.c functions that
work on saving the processor state.
Signed-off-by: Sergio Luis <sergio@larces.uece.br>
Signed-off-by: Lauro Salmito <laurosalmito@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Aiming total unification of cpu_32.c and cpu_64.c, in this step
we do unify the global variables and existing forward declarations
for such files.
Signed-off-by: Sergio Luis <sergio@larces.uece.br>
Signed-off-by: Lauro Salmito <laurosalmito@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
First step towards the unification of cpu_32.c and cpu_64.c.
This commit unifies the headers of such files, making both
of them use the same header files. It also remove the uneeded
<module.h>.
Signed-off-by: Sergio Luis <sergio@larces.uece.br>
Signed-off-by: Lauro Salmito <laurosalmito@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This patch enables the use of wrapper routines to access the debug/breakpoint
registers on cpu management.
The hardcoded debug registers save and restore operations for threads
breakpoints are replaced by wrappers.
And now that we handle the kernel breakpoints too, we also need to handle them
on cpu hotplug operations.
[ Impact: adapt new hardware breakpoint api to cpu hotplug ]
Original-patch-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
The generic hardware breakpoint interface provides an abstraction of
hardware breakpoints in front of specific arch implementations for both kernel
and user side breakpoints.
This includes execution breakpoints and read/write breakpoints, also known as
"watchpoints".
This patch introduces header files containing constants, structure definitions
and declaration of functions used by the hardware breakpoint core and x86
specific code.
It also introduces an array based storage for the debug-register values in
'struct thread_struct', while modifying all users of debugreg<n> member in the
structure.
[ Impact: add headers for new hardware breakpoint interface ]
Original-patch-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
The __restore_processor_state() fn restores %gs on resume from S3. As
such, it cannot be protected by the stack-protector guard since %gs will
not be correct on function entry.
There are only a few other fns in this file and it should not negatively
impact kernel security that they will also have the stack-protector
guard removed (and so it's not worth moving them to another file).
Without this change, S3 resume on a kernel built with
CONFIG_CC_STACKPROTECTOR_ALL=y will fail.
Signed-off-by: Joseph Cihula <joseph.cihula@intel.com>
Tested-by: Chris Wright <chrisw@sous-sol.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Tejun Heo <tj@kernel.org>
LKML-Reference: <49D13385.5060900@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Make the following header file changes:
- remove arch ifdefs and asm/suspend.h from linux/suspend.h
- add asm/suspend.h to disk.c (for arch_prepare_suspend())
- add linux/io.h to swsusp.c (for ioremap())
- x86 32/64 bit compile fixes
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Cc: Paul Mundt <lethal@linux-sh.org>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In general, the only definitions that assembly files can use
are in _types.S headers (where available), so convert them.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Impact: fix crash during hibernation on 32-bit NUMA
The NUMA code on x86_32 creates special memory mapping that allows
each node's pgdat to be located in this node's memory. For this
purpose it allocates a memory area at the end of each node's memory
and maps this area so that it is accessible with virtual addresses
belonging to low memory. As a result, if there is high memory,
these NUMA-allocated areas are physically located in high memory,
although they are mapped to low memory addresses.
Our hibernation code does not take that into account and for this
reason hibernation fails on all x86_32 systems with CONFIG_NUMA=y and
with high memory present. Fix this by adding a special mapping for
the NUMA-allocated memory areas to the temporary page tables created
during the last phase of resume.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add the missing XCR0(XFEATURE_ENABLED_MASK) restore during resume.
Reported-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
arch/x86/power/cpu_32.c __save_processor_state calls read_cr4()
only a i486 CPU doesn't have the CR4 register. Trying to read it
produces an invalid opcode oops during suspend to disk.
Use the safe rc4 reading op instead. If the value to be written is
zero the write is skipped.
arch/x86/power/hibernate_asm_32.S
done: swapped the use of %eax and %ecx to use jecxz for
the zero test and jump over store to %cr4.
restore_image: s/%ecx/%eax/ to be consistent with done:
In addition to __save_processor_state, acpi_save_state_mem,
efi_call_phys_prelog, and efi_call_phys_epilog had checks added
(acpi restore was in assembly and already had a check for
non-zero). There were other reads and writes of CR4, but MCE and
virtualization shouldn't be executed on a i486 anyway.
Signed-off-by: David Fries <david@fries.net>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
By including <asm/processor-flags.h> we're allowed to use
X86_CR4_PGE instead of numeric constant.
md5 sums of compiled files are differ due to this inclusion
but .text section remains the same.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
In some suspend and hibernation files in arch/x86/power there are
comments referring to arch/x86-64 and arch/i386 . Update them to
reflect the current code layout.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Move the hibernation-specific code from arch/x86/power/suspend_64.c
to a separate file (hibernate_64.c) and the CPU-handling code to
cpu_64.c (in line with the corresponding 32-bit code).
Simplify arch/x86/power/Makefile .
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Rename cpu.c, suspend.c and swsusp.S in arch/x86/power to cpu_32.c,
hibernate_32.c and hibernate_asm_32.S, respectively, and update the
purpose and copyright information in these files.
Update the Makefile in arch/x86/power to reflect the above changes.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Move arch/x86/kernel/suspend_64.c to arch/x86/power .
Move arch/x86/kernel/suspend_asm_64.S to arch/x86/power
as hibernate_asm_64.S .
Update purpose and copyright information in
arch/x86/power/suspend_64.c and
arch/x86/power/hibernate_asm_64.S .
Update the Makefiles in arch/x86, arch/x86/kernel and
arch/x86/power to reflect the above changes.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
.. allowing to remove their declarations from a global include file
(the symbols don't exist for anything but x86).
Likewise for 64-bits' fix_processor_context(), just that that one was
properly declared in an arch-specific header.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This replaces the debugreg[7] member of thread_struct with individual
members debugreg0, etc. This saves two words for the dummies 4 and 5,
and harmonizes the code between 32 and 64.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Frederic Weisbecker