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2023-08-22samples: ftrace: Replace bti assembly with hint for older compilerGONG, Ruiqi5-7/+7
When cross-building the arm64 kernel with allmodconfig using GCC 9.4, the following error occurs on multiple files under samples/ftrace/: /tmp/ccPC1ODs.s: Assembler messages: /tmp/ccPC1ODs.s:8: Error: selected processor does not support `bti c' Fix this issue by replacing `bti c` with `hint 34`, which is compatible for the older compiler. Link: https://lore.kernel.org/linux-trace-kernel/20230820111509.1470826-1-gongruiqi@huaweicloud.com Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Florent Revest <revest@chromium.org> Fixes: 8c3526fb86060cb5 ("arm64: ftrace: Add direct call trampoline samples support") Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: GONG, Ruiqi <gongruiqi1@huawei.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-07-11arm64: ftrace: Add direct call trampoline samples supportFlorent Revest5-0/+149
The ftrace samples need per-architecture trampoline implementations to save and restore argument registers around the calls to my_direct_func* and to restore polluted registers (eg: x30). These samples also include <asm/asm-offsets.h> which, on arm64, is not necessary and redefines previously defined macros (resulting in warnings) so these includes are guarded by !CONFIG_ARM64. Link: https://lkml.kernel.org/r/20230427140700.625241-3-revest@chromium.org Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Florent Revest <revest@chromium.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-07-11samples: ftrace: Save required argument registers in sample trampolinesFlorent Revest1-6/+8
The ftrace-direct-too sample traces the handle_mm_fault function whose signature changed since the introduction of the sample. Since: commit bce617edecad ("mm: do page fault accounting in handle_mm_fault") handle_mm_fault now has 4 arguments. Therefore, the sample trampoline should save 4 argument registers. s390 saves all argument registers already so it does not need a change but x86_64 needs an extra push and pop. This also evolves the signature of the tracing function to make it mirror the signature of the traced function. Link: https://lkml.kernel.org/r/20230427140700.625241-2-revest@chromium.org Cc: stable@vger.kernel.org Fixes: bce617edecad ("mm: do page fault accounting in handle_mm_fault") Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Florent Revest <revest@chromium.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-05-04Merge tag 'loongarch-6.4' of ↵Linus Torvalds5-0/+150
git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson Pull LoongArch updates from Huacai Chen: - Better backtraces for humanization - Relay BCE exceptions to userland as SIGSEGV - Provide kernel fpu functions - Optimize memory ops (memset/memcpy/memmove) - Optimize checksum and crc32(c) calculation - Add ARCH_HAS_FORTIFY_SOURCE selection - Add function error injection support - Add ftrace with direct call support - Add basic perf tools support * tag 'loongarch-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson: (24 commits) tools/perf: Add basic support for LoongArch LoongArch: ftrace: Add direct call trampoline samples support LoongArch: ftrace: Add direct call support LoongArch: ftrace: Implement ftrace_find_callable_addr() to simplify code LoongArch: ftrace: Fix build error if DYNAMIC_FTRACE_WITH_REGS is not set LoongArch: ftrace: Abstract DYNAMIC_FTRACE_WITH_ARGS accesses LoongArch: Add support for function error injection LoongArch: Add ARCH_HAS_FORTIFY_SOURCE selection LoongArch: crypto: Add crc32 and crc32c hw acceleration LoongArch: Add checksum optimization for 64-bit system LoongArch: Optimize memory ops (memset/memcpy/memmove) LoongArch: Provide kernel fpu functions LoongArch: Relay BCE exceptions to userland as SIGSEGV with si_code=SEGV_BNDERR LoongArch: Tweak the BADV and CPUCFG.PRID lines in show_regs() LoongArch: Humanize the ESTAT line when showing registers LoongArch: Humanize the ECFG line when showing registers LoongArch: Humanize the EUEN line when showing registers LoongArch: Humanize the PRMD line when showing registers LoongArch: Humanize the CRMD line when showing registers LoongArch: Fix format of CSR lines during show_regs() ...
2023-05-01LoongArch: ftrace: Add direct call trampoline samples supportYouling Tang5-0/+150
The ftrace samples need per-architecture trampoline implementations to save and restore argument registers around the calls to my_direct_func* and to restore polluted registers (e.g: ra). Signed-off-by: Qing Zhang <zhangqing@loongson.cn> Signed-off-by: Youling Tang <tangyouling@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-03-21ftrace: Rename _ftrace_direct_multi APIs to _ftrace_direct APIsFlorent Revest5-16/+16
Now that the original _ftrace_direct APIs are gone, the "_multi" suffixes only add confusion. Link: https://lkml.kernel.org/r/20230321140424.345218-5-revest@chromium.org Signed-off-by: Florent Revest <revest@chromium.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-21ftrace: Replace uses of _ftrace_direct APIs with _ftrace_direct_multiFlorent Revest3-14/+22
The _multi API requires that users keep their own ops but can enforce that an op is only associated to one direct call. Link: https://lkml.kernel.org/r/20230321140424.345218-3-revest@chromium.org Signed-off-by: Florent Revest <revest@chromium.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-03-21ftrace: Let unregister_ftrace_direct_multi() call ftrace_free_filter()Florent Revest2-4/+2
A common pattern when using the ftrace_direct_multi API is to unregister the ops and also immediately free its filter. We've noticed it's very easy for users to miss calling ftrace_free_filter(). This adds a "free_filters" argument to unregister_ftrace_direct_multi() to both remind the user they should free filters and also to make their life easier. Link: https://lkml.kernel.org/r/20230321140424.345218-2-revest@chromium.org Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Florent Revest <revest@chromium.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-02-07samples: ftrace: Make some global variables staticTom Rix1-12/+12
smatch reports this representative issue samples/ftrace/ftrace-ops.c:15:14: warning: symbol 'nr_function_calls' was not declared. Should it be static? The nr_functions_calls and several other global variables are only used in ftrace-ops.c, so they should be static. Remove the instances of initializing static int to 0. Link: https://lore.kernel.org/linux-trace-kernel/20230130193708.1378108-1-trix@redhat.com Signed-off-by: Tom Rix <trix@redhat.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-02-07ftrace: sample: avoid open-coded 64-bit divisionArnd Bergmann1-1/+1
Calculating the average period requires a 64-bit division that leads to a link failure on 32-bit architectures: x86_64-linux-ld: samples/ftrace/ftrace-ops.o: in function `ftrace_ops_sample_init': ftrace-ops.c:(.init.text+0x23b): undefined reference to `__udivdi3' Use the div_u64() helper to do this instead. Since this is an init function that is not called frequently, the runtime overhead is going to be acceptable. Link: https://lore.kernel.org/linux-trace-kernel/20230130130246.247537-1-arnd@kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Fixes: b56c68f705ca ("ftrace: Add sample with custom ops") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-02-07samples: ftrace: Include the nospec-branch.h only for x86Song Shuai5-5/+5
When other architectures without the nospec functionality write their direct-call functions of samples/ftrace/*.c, the including of asm/nospec-branch.h must be taken care to fix the no header file found error in building process. This commit (ee3e2469b346 "x86/ftrace: Make it call depth tracking aware") file-globally includes asm/nospec-branch.h providing CALL_DEPTH_ACCOUNT for only x86 direct-call functions. It seems better to move the including to `#ifdef CONFIG_X86_64`. Link: https://lore.kernel.org/linux-trace-kernel/20230130085954.647845-1-suagrfillet@gmail.com Signed-off-by: Song Shuai <suagrfillet@gmail.com> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-01-25ftrace: Add sample with custom opsMark Rutland2-0/+253
When reworking core ftrace code or architectural ftrace code, it's often necessary to test/analyse/benchmark a number of ftrace_ops configurations. This patch adds a module which can be used to explore some of those configurations. I'm using this to benchmark various options for changing the way trampolines and handling of ftrace_ops work on arm64, and ensuring other architectures aren't adversely affected. For example, in a QEMU+KVM VM running on a 2GHz Xeon E5-2660 workstation, loading the module in various configurations produces: | # insmod ftrace-ops.ko | ftrace_ops: registering: | relevant ops: 1 | tracee: tracee_relevant [ftrace_ops] | tracer: ops_func_nop [ftrace_ops] | irrelevant ops: 0 | tracee: tracee_irrelevant [ftrace_ops] | tracer: ops_func_nop [ftrace_ops] | saving registers: NO | assist recursion: NO | assist RCU: NO | ftrace_ops: Attempted 100000 calls to tracee_relevant [ftrace_ops] in 1681558ns (16ns / call) | # insmod ftrace-ops.ko nr_ops_irrelevant=5 | ftrace_ops: registering: | relevant ops: 1 | tracee: tracee_relevant [ftrace_ops] | tracer: ops_func_nop [ftrace_ops] | irrelevant ops: 5 | tracee: tracee_irrelevant [ftrace_ops] | tracer: ops_func_nop [ftrace_ops] | saving registers: NO | assist recursion: NO | assist RCU: NO | ftrace_ops: Attempted 100000 calls to tracee_relevant [ftrace_ops] in 1693042ns (16ns / call) | # insmod ftrace-ops.ko nr_ops_relevant=2 | ftrace_ops: registering: | relevant ops: 2 | tracee: tracee_relevant [ftrace_ops] | tracer: ops_func_nop [ftrace_ops] | irrelevant ops: 0 | tracee: tracee_irrelevant [ftrace_ops] | tracer: ops_func_nop [ftrace_ops] | saving registers: NO | assist recursion: NO | assist RCU: NO | ftrace_ops: Attempted 100000 calls to tracee_relevant [ftrace_ops] in 11965582ns (119ns / call) | # insmod ftrace-ops.ko save_regs=true | ftrace_ops: registering: | relevant ops: 1 | tracee: tracee_relevant [ftrace_ops] | tracer: ops_func_nop [ftrace_ops] | irrelevant ops: 0 | tracee: tracee_irrelevant [ftrace_ops] | tracer: ops_func_nop [ftrace_ops] | saving registers: YES | assist recursion: NO | assist RCU: NO | ftrace_ops: Attempted 100000 calls to tracee_relevant [ftrace_ops] in 4459624ns (44ns / call) Link: https://lkml.kernel.org/r/20230103124912.2948963-4-mark.rutland@arm.com Cc: Florent Revest <revest@chromium.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-01-24ftrace: Export ftrace_free_filter() to modulesMark Rutland2-0/+2
Setting filters on an ftrace ops results in some memory being allocated for the filter hashes, which must be freed before the ops can be freed. This can be done by removing every individual element of the hash by calling ftrace_set_filter_ip() or ftrace_set_filter_ips() with `remove` set, but this is somewhat error prone as it's easy to forget to remove an element. Make it easier to clean this up by exporting ftrace_free_filter(), which can be used to clean up all of the filter hashes after an ftrace_ops has been unregistered. Using this, fix the ftrace-direct* samples to free hashes prior to being unloaded. All other code either removes individual filters explicitly or is built-in and already calls ftrace_free_filter(). Link: https://lkml.kernel.org/r/20230103124912.2948963-3-mark.rutland@arm.com Cc: stable@vger.kernel.org Cc: Florent Revest <revest@chromium.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Fixes: e1067a07cfbc ("ftrace/samples: Add module to test multi direct modify interface") Fixes: 5fae941b9a6f ("ftrace/samples: Add multi direct interface test module") Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-10-17x86/ftrace: Make it call depth tracking awarePeter Zijlstra5-0/+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
2022-03-15x86/ibt,ftrace: Add ENDBR to samples/ftracePeter Zijlstra5-4/+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
2022-01-13Merge tag 'x86_core_for_v5.17_rc1' of ↵Linus Torvalds3-4/+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 ...
2022-01-06ftrace/samples: Add missing prototypes direct functionsJiri Olsa4-0/+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>
2021-12-09ftrace/samples: Add module to test multi direct modify interfaceJiri Olsa2-0/+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>
2021-12-08x86: Prepare inline-asm for straight-line-speculationPeter Zijlstra3-4/+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
2021-11-18ftrace/samples: add s390 support for ftrace direct multi sampleHeiko Carstens1-0/+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>
2021-11-18ftrace/samples: add missing Kconfig option for ftrace direct multi sampleHeiko Carstens1-1/+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>
2021-11-07Merge tag 's390-5.16-1' of ↵Linus Torvalds4-1/+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 ...
2021-11-02ftrace/samples: Add missing prototype for my_direct_funcJiri Olsa1-0/+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>
2021-10-21ftrace/samples: Add multi direct interface test moduleJiri Olsa2-0/+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>
2021-10-19samples: add s390 support for ftrace direct call samplesHeiko Carstens3-0/+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>
2020-12-01samples/ftrace: Mark my_tramp[12]? globalSami Tolvanen3-0/+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>
2020-06-17sample-trace-array: Remove trace_array 'sample-instance'Kefeng Wang1-1/+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>
2020-06-17sample-trace-array: Fix sleeping function called from invalid contextKefeng Wang1-5/+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>
2020-05-20samples/ftrace: Fix asm function ELF annotationsJosh Poimboeuf3-0/+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>
2019-11-23tracing: Sample module to demonstrate kernel access to Ftrace instances.Divya Indi3-0/+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>
2019-11-15ftrace/selftests: Fix spelling mistake "wakeing" -> "waking"Colin Ian King1-1/+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>
2019-11-15ftrace/samples: Add a sample module that implements modify_ftrace_direct()Steven Rostedt (VMware)2-0/+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>
2019-11-13ftrace: Add another example of register_ftrace_direct() use caseSteven Rostedt (VMware)2-0/+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>
2019-11-13ftrace: Add sample module that uses register_ftrace_direct()Steven Rostedt (VMware)2-0/+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>