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2013-04-14[media] mt9p031: Use devm_* managed helpersLaurent Pinchart
Replace kzalloc and gpio_request_one by their managed equivalents. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2013-04-14[media] mt9m032: Define MT9M032_READ_MODE1 bitsLaurent Pinchart
Replace hardcoded values with #define's. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2013-04-14[media] mt9m032: Fix PLL setupLaurent Pinchart
The MT9M032 PLL was assumed to be identical to the MT9P031 PLL but differs significantly. Update the registers definitions and PLL limits according to the datasheet. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2013-04-14[media] exynos4-is: Disable debug trace by default in fimc-isp.cSylwester Nawrocki
Make sure the debug level is properly set initially so any debug information is not printed to the kernel log without explicitly enabling it. Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2013-04-14[media] exynos4-is: Remove meaningless test before bit settingSylwester Nawrocki
There is no need to check same bit before setting it, since we always end up with a bit set. Remove some of the tests and make set unconditional, in every place where all that needs to be done is just setting a bit. Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2013-04-14[media] exynos4-is: Rename the ISP chain configuration data structureSylwester Nawrocki
More appropriate names for the ISP chain data structure. Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2013-04-14[media] exynos4-is: Improve the ISP chain parameter count calculationSylwester Nawrocki
Instead of incrementing p_region_num field each time we set a bit in the parameter mask calculate the number of bits set only when this information is needed. Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2013-04-14[media] exynos4-is: Make fimc-lite independent of struct fimc_sensor_infoSylwester Nawrocki
Make the sensor subdevs host_data hold a pointer to struct fimc_source_info, which is defined in the driver's public header, rather than a pointer to struct fimc_sensor_info which is specific to exynos4-is media device driver. The purpose of this change is to allow easier reuse of the fimc-lite module in the exynos5-is driver, which should similarly store a pointer to struct fimc_source_info instance in the sensor's subdev host_data. Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2013-04-14[media] exynos4-is: Make fimc-lite independent of the pipeline->subdevs arraySylwester Nawrocki
Get the sensor subdev by walking media graph in both cases: when the device is used as a subdev only and through video node. This allows to not dereference the pipeline->subdevs[] array and makes the module more generic and easier to re-use in other media driver. Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2013-04-14[media] exynos4-is: Move the subdev group ID definitions to public headerSylwester Nawrocki
Move the sub-device group ID definitions to the driver's public header so they are available to other media drivers that need to share modules found in exynos4-is. Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2013-04-14[media] s5p-mfc: Remove potential uninitialized variable usageSylwester Nawrocki
Make sure mem_info[] array is not used uninitialized. This prevents following compiler warning: drivers/media/platform/s5p-mfc/s5p_mfc.c: In function s5p_mfc_probe: drivers/media/platform/s5p-mfc/s5p_mfc.c:1032:33: warning: mem_info[0] may be used uninitialized in this function [-Wuninitialized] drivers/media/platform/s5p-mfc/s5p_mfc.c:1021:15: note: mem_info[0] was declared here drivers/media/platform/s5p-mfc/s5p_mfc.c:1032:33: warning: mem_info[1] may be used uninitialized in this function [-Wuninitialized] drivers/media/platform/s5p-mfc/s5p_mfc.c:1021:15: note: mem_info[1] was declared here Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2013-04-14Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "Misc fixes" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm: Flush lazy MMU when DEBUG_PAGEALLOC is set x86/mm/cpa/selftest: Fix false positive in CPA self test x86/mm/cpa: Convert noop to functional fix x86, mm: Patch out arch_flush_lazy_mmu_mode() when running on bare metal x86, mm, paravirt: Fix vmalloc_fault oops during lazy MMU updates
2013-04-14Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "Misc fixlets" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/cputime: Fix accounting on multi-threaded processes sched/debug: Fix sd->*_idx limit range avoiding overflow sched_clock: Prevent 64bit inatomicity on 32bit systems sched: Convert BUG_ON()s in try_to_wake_up_local() to WARN_ON_ONCE()s
2013-04-14Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Misc fixlets" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Fix error return code ftrace: Fix strncpy() use, use strlcpy() instead of strncpy() perf: Fix strncpy() use, use strlcpy() instead of strncpy() perf: Fix strncpy() use, always make sure it's NUL terminated perf: Fix ring_buffer perf_output_space() boundary calculation perf/x86: Fix uninitialized pt_regs in intel_pmu_drain_bts_buffer()
2013-04-14Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linuxLinus Torvalds
Pull drm fixes from Dave Airlie: "One fix for a hotplug locking regressions, and one fix for an oops if you unplug the monitor at an inopportune moment on the udl device." * 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: drm/fb-helper: Fix locking in drm_fb_helper_hotplug_event udl: handle EDID failure properly.
2013-04-14Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu Pull m68knommu fix from Greg Ungerer: "This contains only a single compilation fix for ColdFire m68k targets that use local non-GPIOLIB support." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu: m68k: define a local gpio_request_one() function
2013-04-14Merge git://www.linux-watchdog.org/linux-watchdogLinus Torvalds
Pull watchdog fix from Wim Van Sebroeck: "It will fix compile errors for the at91rm9200_wdt driver" * git://www.linux-watchdog.org/linux-watchdog: watchdog: Revert the AT91RM9200_WATCHDOG dependency
2013-04-14Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull one more btrfs fix from Chris Mason: "This has a recent fix from Josef for our tree log replay code. It fixes problems where the inode counter for the number of bytes in the file wasn't getting updated properly during fsync replay. The commit did get rebased this morning, but it was only to clean up the subject line. The code hasn't changed." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Btrfs: make sure nbytes are right after log replay
2013-04-14Merge tag 'trace-fixes-v3.9-rc-v3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull ftrace fixes from Steven Rostedt: "Namhyung Kim found and fixed a bug that can crash the kernel by simply doing: echo 1234 | tee -a /sys/kernel/debug/tracing/set_ftrace_pid Luckily, this can only be done by root, but still is a nasty bug." * tag 'trace-fixes-v3.9-rc-v3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ftrace: Move ftrace_filter_lseek out of CONFIG_DYNAMIC_FTRACE section tracing: Fix possible NULL pointer dereferences
2013-04-14cgroup: make cgroup_path() not print double slashesTejun Heo
While reimplementing cgroup_path(), 65dff759d2 ("cgroup: fix cgroup_path() vs rename() race") introduced a bug where the path of a non-root cgroup would have two slahses at the beginning, which is caused by treating the root cgroup which has the name '/' like non-root cgroups. $ grep systemd /proc/self/cgroup 1:name=systemd://user/root/1 Fix it by special casing root cgroup case and not looping over it in the normal path. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Li Zefan <lizefan@huawei.com>
2013-04-14Add file_ns_capable() helper function for open-time capability checkingLinus Torvalds
Nothing is using it yet, but this will allow us to delay the open-time checks to use time, without breaking the normal UNIX permission semantics where permissions are determined by the opener (and the file descriptor can then be passed to a different process, or the process can drop capabilities). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-14NFSv4.1: Set the RPC_CLNT_CREATE_INFINITE_SLOTS flag for NFSv4.1 transportsTrond Myklebust
This ensures that the RPC layer doesn't override the NFS session negotiation. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-04-14SUNRPC: Allow rpc_create() to request that TCP slots be unlimitedTrond Myklebust
This is mainly for use by NFSv4.1, where the session negotiation ultimately wants to decide how many RPC slots we can fill. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-04-14SUNRPC: Fix a livelock problem in the xprt->backlog queueTrond Myklebust
This patch ensures that we throttle new RPC requests if there are requests already waiting in the xprt->backlog queue. The reason for doing this is to fix livelock issues that can occur when an existing (high priority) task is waiting in the backlog queue, gets woken up by xprt_free_slot(), but a new task then steals the slot. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-04-14hwmon: (tmp401) Use sysfs_create_group / sysfs_remove_groupGuenter Roeck
instead of creating and removing sysfs attribute files individually. Acked-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2013-04-14hwmon: (tmp401) Drop unused defines, use BIT for bit masksGuenter Roeck
Signed-off-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Jean Delvare <khali@linux-fr.org>
2013-04-14watchdog: Revert the AT91RM9200_WATCHDOG dependencyNicolas Ferre
Compiling the at91rm9200_wdt.c driver without at91rm9200 support was leading to several errors: drivers/built-in.o: In function `at91_wdt_close': at91_adc.c:(.text+0xc9fe4): undefined reference to `at91_st_base' drivers/built-in.o: In function `at91_wdt_write': at91_adc.c:(.text+0xca004): undefined reference to `at91_st_base' drivers/built-in.o: In function `at91wdt_shutdown': at91_adc.c:(.text+0xca01c): undefined reference to `at91_st_base' drivers/built-in.o: In function `at91wdt_suspend': at91_adc.c:(.text+0xca038): undefined reference to `at91_st_base' drivers/built-in.o: In function `at91_wdt_open': at91_adc.c:(.text+0xca0cc): undefined reference to `at91_st_base' drivers/built-in.o:at91_adc.c:(.text+0xca2c8): more undefined references to `at91_st_base' follow So, reverting the modification of the "depends" Kconfig line introduced by patch a6a1bcd37 (watchdog: at91rm9200: add DT support) seems to be the good solution. Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Acked-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2013-04-14clk: vt8500: Missing breaks in vtwm_pll_round_rate/_set_rate.Tony Prisk
The case of PLL_TYPE_WM8750 in both these functions is missing a break statement causing a fall-through to the default: case. Insert the missing break statements. Signed-off-by: Tony Prisk <linux@prisktech.co.nz> Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-04-13vfs: Revert spurious fix to spinning prevention in prune_icache_sbSuleiman Souhlal
Revert commit 62a3ddef6181 ("vfs: fix spinning prevention in prune_icache_sb"). This commit doesn't look right: since we are looking at the tail of the list (sb->s_inode_lru.prev) if we want to skip an inode, we should put it back at the head of the list instead of the tail, otherwise we will keep spinning on it. Discovered when investigating why prune_icache_sb came top in perf reports of a swapping load. Signed-off-by: Suleiman Souhlal <suleiman@google.com> Signed-off-by: Hugh Dickins <hughd@google.com> Cc: stable@vger.kernel.org # v3.2+ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-13kobject: fix kset_find_obj() race with concurrent last kobject_put()Linus Torvalds
Anatol Pomozov identified a race condition that hits module unloading and re-loading. To quote Anatol: "This is a race codition that exists between kset_find_obj() and kobject_put(). kset_find_obj() might return kobject that has refcount equal to 0 if this kobject is freeing by kobject_put() in other thread. Here is timeline for the crash in case if kset_find_obj() searches for an object tht nobody holds and other thread is doing kobject_put() on the same kobject: THREAD A (calls kset_find_obj()) THREAD B (calls kobject_put()) splin_lock() atomic_dec_return(kobj->kref), counter gets zero here ... starts kobject cleanup .... spin_lock() // WAIT thread A in kobj_kset_leave() iterate over kset->list atomic_inc(kobj->kref) (counter becomes 1) spin_unlock() spin_lock() // taken // it does not know that thread A increased counter so it remove obj from list spin_unlock() vfree(module) // frees module object with containing kobj // kobj points to freed memory area!! kobject_put(kobj) // OOPS!!!! The race above happens because module.c tries to use kset_find_obj() when somebody unloads module. The module.c code was introduced in commit 6494a93d55fa" Anatol supplied a patch specific for module.c that worked around the problem by simply not using kset_find_obj() at all, but rather than make a local band-aid, this just fixes kset_find_obj() to be thread-safe using the proper model of refusing the get a new reference if the refcount has already dropped to zero. See examples of this proper refcount handling not only in the kref documentation, but in various other equivalent uses of this pattern by grepping for atomic_inc_not_zero(). [ Side note: the module race does indicate that module loading and unloading is not properly serialized wrt sysfs information using the module mutex. That may require further thought, but this is the correct fix at the kobject layer regardless. ] Reported-analyzed-and-tested-by: Anatol Pomozov <anatol.pomozov@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-13net: mvmdio: add select PHYLIBThomas Petazzoni
The mvmdio driver uses the phylib API, so it should select the PHYLIB symbol, otherwise, a build with mvmdio (but without mvneta) fails to build with undefined symbols such as mdiobus_unregister, mdiobus_free, etc. The mvneta driver does not use the phylib API directly, so it does not need to select PHYLIB. It already selects the mvmdio driver anyway. Historically, this problem is due to the fact that the PHY handling was originally part of mvneta, and was later moved to a separate driver, without updating the Kconfig select statements accordingly. And since there was no functional reason to use mvmdio without mvneta, this case was not tested. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-13sparc: Use generic idle loopSam Ravnborg
Add generic cpu_idle support sparc32: - replace call to cpu_idle() with cpu_startup_entry() - add arch_cpu_idle() sparc64: - smp_callin() now include cpu_startup_entry() call so we can skip calling cpu_idle from assembler - add arch_cpu_idle() and arch_cpu_idle_dead() Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Reviewed-by: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com> Cc: torvalds@linux-foundation.org Cc: rusty@rustcorp.com.au Cc: paulmck@linux.vnet.ibm.com Cc: peterz@infradead.org Cc: magnus.damm@gmail.com Acked-by: David Miller <davem@davemloft.net> Link: http://lkml.kernel.org/r/20130411193850.GA2330@merkur.ravnborg.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-04-13hwmon: (nct6775) Use ARRAY_SIZE for loops where possibleGuenter Roeck
This ensures that the loop iterations are correct even if/when the number of elements in an array changes. Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2013-04-13uprobes/tracing: Don't pass addr=ip to perf_trace_buf_submit()Oleg Nesterov
uprobe_perf_print() passes addr=ip to perf_trace_buf_submit() for no reason. This sets perf_sample_data->addr for PERF_SAMPLE_ADDR, we already have perf_sample_data->ip initialized if PERF_SAMPLE_IP. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2013-04-13uprobes/tracing: Change create_trace_uprobe() to support uretprobesOleg Nesterov
Finally change create_trace_uprobe() to check if argv[0][0] == 'r' and pass the correct "is_ret" to alloc_trace_uprobe(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Anton Arapov <anton@redhat.com>
2013-04-13uprobes/tracing: Make seq_printf() code uretprobe-friendlyOleg Nesterov
Change probes_seq_show() and print_uprobe_event() to check is_ret_probe() and print the correct data. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Anton Arapov <anton@redhat.com>
2013-04-13uprobes/tracing: Make register_uprobe_event() paths uretprobe-friendlyOleg Nesterov
Change uprobe_event_define_fields(), and __set_print_fmt() to check is_ret_probe() and use the appropriate format/fields. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Anton Arapov <anton@redhat.com>
2013-04-13uprobes/tracing: Make uprobe_{trace,perf}_print() uretprobe-friendlyOleg Nesterov
Change uprobe_trace_print() and uprobe_perf_print() to check is_ret_probe() and fill ring_buffer_event accordingly. Also change uprobe_trace_func() and uprobe_perf_func() to not _print() if is_ret_probe() is true. Note that we keep ->handler() nontrivial even for uretprobe, we need this for filtering and for other potential extensions. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Anton Arapov <anton@redhat.com>
2013-04-13uprobes/tracing: Introduce is_ret_probe() and uretprobe_dispatcher()Oleg Nesterov
Create the new functions we need to support uretprobes, and change alloc_trace_uprobe() to initialize consumer.ret_handler if the new "is_ret" argument is true. Curently this argument is always false, so the new code is never called and is_ret_probe(tu) is false too. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Anton Arapov <anton@redhat.com>
2013-04-13uprobes/tracing: Introduce uprobe_{trace,perf}_print() helpersOleg Nesterov
Extract the output code from uprobe_trace_func() and uprobe_perf_func() into the new helpers, they will be used by ->ret_handler() too. We also add the unused "unsigned long func" argument in advance, to simplify the next changes. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Anton Arapov <anton@redhat.com>
2013-04-13uprobes/tracing: Generalize struct uprobe_trace_entry_headOleg Nesterov
struct uprobe_trace_entry_head has a single member for reporting, "unsigned long ip". If we want to support uretprobes we need to create another struct which has "func" and "ret_ip" and duplicate a lot of functions, like trace_kprobe.c does. To avoid this copy-and-paste horror we turn ->ip into ->vaddr[] and add couple of trivial helpers to calculate sizeof/data. This uglifies the code a bit, but this allows us to avoid a lot more complications later, when we add the support for ret-probes. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Anton Arapov <anton@redhat.com>
2013-04-13uprobes/tracing: Kill the pointless local_save_flags/preempt_count callsOleg Nesterov
uprobe_trace_func() is never called with irqs or preemption disabled, no need to ask preempt_count() or local_save_flags(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Tested-by: Anton Arapov <anton@redhat.com>
2013-04-13uprobes/tracing: Kill the pointless seq_print_ip_sym() callOleg Nesterov
seq_print_ip_sym(ip) in print_uprobe_event() is pointless, kallsyms_lookup(ip) can not resolve a user-space address. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Anton Arapov <anton@redhat.com>
2013-04-13uprobes/tracing: Kill the pointless task_pt_regs() callsOleg Nesterov
uprobe_trace_func() and uprobe_perf_func() do not need task_pt_regs(), we already have "struct pt_regs *regs". Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Anton Arapov <anton@redhat.com>
2013-04-13uretprobes: Documentation updateAnton Arapov
add the uretprobe syntax and update an example Signed-off-by: Anton Arapov <anton@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2013-04-13uretprobes: Remove -ENOSYS as return probes implementedAnton Arapov
Enclose return probes implementation. Signed-off-by: Anton Arapov <anton@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2013-04-13uretprobes: Limit the depth of return probe nestednessAnton Arapov
Unlike the kretprobes we can't trust userspace, thus must have protection from user space attacks. User-space have "unlimited" stack, and this patch limits the return probes nestedness as a simple remedy for it. Note that this implementation leaks return_instance on siglongjmp until exit()/exec(). The intention is to have KISS and bare minimum solution for the initial implementation in order to not complicate the uretprobes code. In the future we may come up with more sophisticated solution that remove this depth limitation. It is not easy task and lays beyond this patchset. Signed-off-by: Anton Arapov <anton@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2013-04-13uretprobes: Return probe exit, invoke handlersAnton Arapov
Uretprobe handlers are invoked when the trampoline is hit, on completion the trampoline is replaced with the saved return address and the uretprobe instance deleted. TODO: handle_trampoline() assumes that ->return_instances is always valid. We should teach it to handle longjmp() which can invalidate the pending return_instance's. This is nontrivial, we will try to do this in a separate series. Signed-off-by: Anton Arapov <anton@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2013-04-13uretprobes: Return probe entry, prepare_uretprobe()Anton Arapov
When a uprobe with return probe consumer is hit, prepare_uretprobe() function is invoked. It creates return_instance, hijacks return address and replaces it with the trampoline. * Return instances are kept as stack per uprobed task. * Return instance is chained, when the original return address is trampoline's page vaddr (e.g. recursive call of the probed function). Signed-off-by: Anton Arapov <anton@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2013-04-13uretprobes/powerpc: Hijack return addressAnton Arapov
Hijack the return address and replace it with a trampoline address. PowerPC implementation. Signed-off-by: Anton Arapov <anton@redhat.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com>