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* x86/ftrace: Make it call depth tracking awarePeter Zijlstra2022-10-175-0/+12
| | | | | | | | | | | | | | | | | | | | | | Since ftrace has trampolines, don't use thunks for the __fentry__ site but instead require that every function called from there includes accounting. This very much includes all the direct-call functions. Additionally, ftrace uses ROP tricks in two places: - return_to_handler(), and - ftrace_regs_caller() when pt_regs->orig_ax is set by a direct-call. return_to_handler() already uses a retpoline to replace an indirect-jump to defeat IBT, since this is a jump-type retpoline, make sure there is no accounting done and ALTERNATIVE the RET into a ret. ftrace_regs_caller() does much the same and gets the same treatment. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220915111148.927545073@infradead.org
* x86/ibt,ftrace: Add ENDBR to samples/ftracePeter Zijlstra2022-03-155-4/+22
| | | | | | Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154318.523421433@infradead.org
* Merge tag 'x86_core_for_v5.17_rc1' of ↵Linus Torvalds2022-01-133-4/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 core updates from Borislav Petkov: - Get rid of all the .fixup sections because this generates misleading/wrong stacktraces and confuse RELIABLE_STACKTRACE and LIVEPATCH as the backtrace misses the function which is being fixed up. - Add Straight Line Speculation mitigation support which uses a new compiler switch -mharden-sls= which sticks an INT3 after a RET or an indirect branch in order to block speculation after them. Reportedly, CPUs do speculate behind such insns. - The usual set of cleanups and improvements * tag 'x86_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits) x86/entry_32: Fix segment exceptions objtool: Remove .fixup handling x86: Remove .fixup section x86/word-at-a-time: Remove .fixup usage x86/usercopy: Remove .fixup usage x86/usercopy_32: Simplify __copy_user_intel_nocache() x86/sgx: Remove .fixup usage x86/checksum_32: Remove .fixup usage x86/vmx: Remove .fixup usage x86/kvm: Remove .fixup usage x86/segment: Remove .fixup usage x86/fpu: Remove .fixup usage x86/xen: Remove .fixup usage x86/uaccess: Remove .fixup usage x86/futex: Remove .fixup usage x86/msr: Remove .fixup usage x86/extable: Extend extable functionality x86/entry_32: Remove .fixup usage x86/entry_64: Remove .fixup usage x86/copy_mc_64: Remove .fixup usage ...
| * x86: Prepare inline-asm for straight-line-speculationPeter Zijlstra2021-12-083-4/+4
| | | | | | | | | | | | | | | | | | Replace all ret/retq instructions with ASM_RET in preparation of making it more than a single instruction. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20211204134907.964635458@infradead.org
* | ftrace/samples: Add missing prototypes direct functionsJiri Olsa2022-01-064-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's another compilation fail (first here [1]) reported by kernel test robot for W=1 clang build: >> samples/ftrace/ftrace-direct-multi-modify.c:7:6: warning: no previous prototype for function 'my_direct_func1' [-Wmissing-prototypes] void my_direct_func1(unsigned long ip) Direct functions in ftrace direct sample modules need to have prototypes defined. They are already global in order to be visible for the inline assembly, so there's no problem. The kernel test robot reported just error for ftrace-direct-multi-modify, but I got same errors also for the rest of the modules touched by this patch. [1] 67d4f6e3bf5d ftrace/samples: Add missing prototype for my_direct_func Link: https://lkml.kernel.org/r/20211219135317.212430-1-jolsa@kernel.org Reported-by: kernel test robot <lkp@intel.com> Fixes: e1067a07cfbc ("ftrace/samples: Add module to test multi direct modify interface") Fixes: ae0cc3b7e7f5 ("ftrace/samples: Add a sample module that implements modify_ftrace_direct()") Fixes: 156473a0ff4f ("ftrace: Add another example of register_ftrace_direct() use case") Fixes: b06457c83af6 ("ftrace: Add sample module that uses register_ftrace_direct()") Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | ftrace/samples: Add module to test multi direct modify interfaceJiri Olsa2021-12-092-0/+153
|/ | | | | | | | | | | | | | | | | | | | Adding ftrace-direct-multi-modify.ko kernel module that uses modify_ftrace_direct_multi API. The core functionality is taken from ftrace-direct-modify.ko kernel module and changed to fit multi direct interface. The init function creates kthread that periodically calls modify_ftrace_direct_multi to change the trampoline address for the direct ftrace_ops. The ftrace trace_pipe then shows trace from both trampolines. Link: https://lkml.kernel.org/r/20211206182032.87248-4-jolsa@kernel.org Cc: Ingo Molnar <mingo@redhat.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Tested-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* ftrace/samples: add s390 support for ftrace direct multi sampleHeiko Carstens2021-11-181-0/+30
| | | | | | | | | Add s390 architecture support for the ftrace direct multi sample. See commit 5fae941b9a6f ("ftrace/samples: Add multi direct interface test module") for further details. Link: https://lore.kernel.org/r/20211115195614.3173346-3-hca@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
* ftrace/samples: add missing Kconfig option for ftrace direct multi sampleHeiko Carstens2021-11-181-1/+1
| | | | | | | | | | | | | | | | | Currently it is not possible to build the ftrace direct multi example anymore due to broken config dependencies. Fix this by adding SAMPLE_FTRACE_DIRECT_MULTI config option. This broke when merging s390-5.16-1 due to an incorrect merge conflict resolution proposed by me. Also rename SAMPLE_FTRACE_MULTI_DIRECT to SAMPLE_FTRACE_DIRECT_MULTI so it matches the module name. Fixes: 0b707e572a19 ("Merge tag 's390-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux") Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Link: https://lore.kernel.org/r/20211115195614.3173346-2-hca@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
* Merge tag 's390-5.16-1' of ↵Linus Torvalds2021-11-064-1/+101
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Vasily Gorbik: - Add support for ftrace with direct call and ftrace direct call samples. - Add support for kernel command lines longer than current 896 bytes and make its length configurable. - Add support for BEAR enhancement facility to improve last breaking event instruction tracking. - Add kprobes sanity checks and testcases to prevent kprobe in the mid of an instruction. - Allow concurrent access to /dev/hwc for the CPUMF users. - Various ftrace / jump label improvements. - Convert unwinder tests to KUnit. - Add s390_iommu_aperture kernel parameter to tweak the limits on concurrently usable DMA mappings. - Add ap.useirq AP module option which can be used to disable interrupt use. - Add add_disk() error handling support to block device drivers. - Drop arch specific and use generic implementation of strlcpy and strrchr. - Several __pa/__va usages fixes. - Various cio, crypto, pci, kernel doc and other small fixes and improvements all over the code. [ Merge fixup as per https://lore.kernel.org/all/YXAqZ%2FEszRisunQw@osiris/ ] * tag 's390-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (63 commits) s390: make command line configurable s390: support command lines longer than 896 bytes s390/kexec_file: move kernel image size check s390/pci: add s390_iommu_aperture kernel parameter s390/spinlock: remove incorrect kernel doc indicator s390/string: use generic strlcpy s390/string: use generic strrchr s390/ap: function rework based on compiler warning s390/cio: make ccw_device_dma_* more robust s390/vfio-ap: s390/crypto: fix all kernel-doc warnings s390/hmcdrv: fix kernel doc comments s390/ap: new module option ap.useirq s390/cpumf: Allow multiple processes to access /dev/hwc s390/bitops: return true/false (not 1/0) from bool functions s390: add support for BEAR enhancement facility s390: introduce nospec_uses_trampoline() s390: rename last_break to pgm_last_break s390/ptrace: add last_break member to pt_regs s390/sclp: sort out physical vs virtual pointers usage s390/setup: convert start and end initrd pointers to virtual ...
| * samples: add s390 support for ftrace direct call samplesHeiko Carstens2021-10-193-0/+100
| | | | | | | | | | | | | | | | | | | | | | | | Add s390 support for ftrace direct call samples, which also enables ftrace direct call selftests within ftrace selftests. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Link: https://lore.kernel.org/r/20211012133802.2460757-5-hca@linux.ibm.com Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
* | ftrace/samples: Add missing prototype for my_direct_funcJiri Olsa2021-11-021-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's compilation fail reported kernel test robot for W=1 build: >> samples/ftrace/ftrace-direct-multi.c:8:6: warning: no previous prototype for function 'my_direct_func' [-Wmissing-prototypes] void my_direct_func(unsigned long ip) The inlined assembly is used outside function, so we can't make my_direct_func static and pass it as asm input argument. However my_tramp is already extern so I think there's no problem keeping my_direct_func extern as well and just add its prototype. Link: https://lkml.kernel.org/r/20211101153907.377668-1-jolsa@kernel.org Reported-by: kernel test robot <lkp@intel.com> Fixes: 5fae941b9a6f ("ftrace/samples: Add multi direct interface test module") Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* | ftrace/samples: Add multi direct interface test moduleJiri Olsa2021-10-212-0/+53
|/ | | | | | | | | | | | | | | Adding simple module that uses multi direct interface: register_ftrace_direct_multi unregister_ftrace_direct_multi The init function registers trampoline for 2 functions, and exit function unregisters them. Link: https://lkml.kernel.org/r/20211008091336.33616-9-jolsa@kernel.org Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* samples/ftrace: Mark my_tramp[12]? globalSami Tolvanen2020-12-013-0/+4
| | | | | | | | | | | | | | my_tramp[12]? are declared as global functions in C, but they are not marked global in the inline assembly definition. This mismatch confuses Clang's Control-Flow Integrity checking. Fix the definitions by adding .globl. Link: https://lkml.kernel.org/r/20201113183414.1446671-1-samitolvanen@google.com Fixes: 9d907f1ae80b8 ("ftrace/samples: Add a sample module that implements modify_ftrace_direct()") Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* sample-trace-array: Remove trace_array 'sample-instance'Kefeng Wang2020-06-171-1/+5
| | | | | | | | | | | | | Remove trace_array 'sample-instance' if kthread_run fails in sample_trace_array_init(). Link: https://lkml.kernel.org/r/20200609135200.2206726-1-wangkefeng.wang@huawei.com Cc: stable@vger.kernel.org Fixes: 89ed42495ef4a ("tracing: Sample module to demonstrate kernel access to Ftrace instances.") Reviewed-by: Divya Indi <divya.indi@oracle.com> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* sample-trace-array: Fix sleeping function called from invalid contextKefeng Wang2020-06-171-5/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BUG: sleeping function called from invalid context at kernel/locking/mutex.c:935 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 0, name: swapper/5 1 lock held by swapper/5/0: #0: ffff80001002bd90 (samples/ftrace/sample-trace-array.c:38){+.-.}-{0:0}, at: call_timer_fn+0x8/0x3e0 CPU: 5 PID: 0 Comm: swapper/5 Not tainted 5.7.0+ #8 Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 Call trace: dump_backtrace+0x0/0x1a0 show_stack+0x20/0x30 dump_stack+0xe4/0x150 ___might_sleep+0x160/0x200 __might_sleep+0x58/0x90 __mutex_lock+0x64/0x948 mutex_lock_nested+0x3c/0x58 __ftrace_set_clr_event+0x44/0x88 trace_array_set_clr_event+0x24/0x38 mytimer_handler+0x34/0x40 [sample_trace_array] mutex_lock() will be called in interrupt context, using workqueue to fix it. Link: https://lkml.kernel.org/r/20200610011244.2209486-1-wangkefeng.wang@huawei.com Cc: stable@vger.kernel.org Fixes: 89ed42495ef4 ("tracing: Sample module to demonstrate kernel access to Ftrace instances.") Reviewed-by: Divya Indi <divya.indi@oracle.com> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* samples/ftrace: Fix asm function ELF annotationsJosh Poimboeuf2020-05-203-0/+8
| | | | | | | | | | | | Enable objtool coverage for the sample ftrace modules by adding ELF annotations to the asm trampoline functions. samples/ftrace/ftrace-direct.o: warning: objtool: .text+0x0: unreachable instruction samples/ftrace/ftrace-direct-modify.o: warning: objtool: .text+0x0: unreachable instruction samples/ftrace/ftrace-direct-too.o: warning: objtool: .text+0x0: unreachable instruction Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
* tracing: Sample module to demonstrate kernel access to Ftrace instances.Divya Indi2019-11-233-0/+218
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a sample module to demonstrate the use of the newly introduced and exported APIs to access Ftrace instances from within the kernel. Newly introduced APIs used here - 1. Create/Lookup a trace array with the given name. struct trace_array *trace_array_get_by_name(const char *name) 2. Destroy/Remove a trace array. int trace_array_destroy(struct trace_array *tr) 4. Enable/Disable trace events: int trace_array_set_clr_event(struct trace_array *tr, const char *system, const char *event, bool enable); Exported APIs - 1. trace_printk equivalent for instances. int trace_array_printk(struct trace_array *tr, unsigned long ip, const char *fmt, ...); 2. Helper function. void trace_printk_init_buffers(void); 3. To decrement the reference counter. void trace_array_put(struct trace_array *tr) Sample output(contents of /sys/kernel/tracing/instances/sample-instance) NOTE: Tracing disabled after ~5 sec) _-----=> irqs-off / _----=> need-resched | / _---=> hardirq/softirq || / _--=> preempt-depth ||| / delay TASK-PID CPU# |||| TIMESTAMP FUNCTION | | | |||| | | sample-instance-1452 [002] .... 49.430948: simple_thread: trace_array_printk: count=0 sample-instance-1452 [002] .... 49.430951: sample_event: count value=0 at jiffies=4294716608 sample-instance-1452 [002] .... 50.454847: simple_thread: trace_array_printk: count=1 sample-instance-1452 [002] .... 50.454849: sample_event: count value=1 at jiffies=4294717632 sample-instance-1452 [002] .... 51.478748: simple_thread: trace_array_printk: count=2 sample-instance-1452 [002] .... 51.478750: sample_event: count value=2 at jiffies=4294718656 sample-instance-1452 [002] .... 52.502652: simple_thread: trace_array_printk: count=3 sample-instance-1452 [002] .... 52.502655: sample_event: count value=3 at jiffies=4294719680 sample-instance-1452 [002] .... 53.526533: simple_thread: trace_array_printk: count=4 sample-instance-1452 [002] .... 53.526535: sample_event: count value=4 at jiffies=4294720704 sample-instance-1452 [002] .... 54.550438: simple_thread: trace_array_printk: count=5 sample-instance-1452 [002] .... 55.574336: simple_thread: trace_array_printk: count=6 Link: http://lkml.kernel.org/r/1574276919-11119-3-git-send-email-divya.indi@oracle.com Reviewed-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com> Signed-off-by: Divya Indi <divya.indi@oracle.com> [ Moved to samples/ftrace ] Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* ftrace/selftests: Fix spelling mistake "wakeing" -> "waking"Colin Ian King2019-11-151-1/+1
| | | | | | | | | | | There is a spelling mistake in a trace_printk message. As well as in the selftests that search for this string. Link: http://lkml.kernel.org/r/20191115085938.38947-1-colin.king@canonical.com Link: http://lkml.kernel.org/r/20191115090356.39572-1-colin.king@canonical.com Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* ftrace/samples: Add a sample module that implements modify_ftrace_direct()Steven Rostedt (VMware)2019-11-152-0/+89
| | | | | | | Add a sample module that tests modify_ftrace_direct(), and this can be used by the selftests as well. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* ftrace: Add another example of register_ftrace_direct() use caseSteven Rostedt (VMware)2019-11-132-0/+52
| | | | | | | | | | Add another module sample that registers a direct trampoline to a function via register_ftrace_direct(). Having another module that does this allows to test the use case of multiple direct callers registered, as more than one direct caller goes into another path, and is needed to perform proper testing of the register_ftrace_direct() call. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* ftrace: Add sample module that uses register_ftrace_direct()Steven Rostedt (VMware)2019-11-132-0/+48
Add a sample module that shows a simple use case for regsiter_ftrace_direct(), and how to use it. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>