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2023-08-21samples: ftrace: Replace bti assembly with hint for older compilerGONG, Ruiqi
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>
2023-07-10arm64: ftrace: Add direct call trampoline samples supportFlorent Revest
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>
2023-05-04Merge tag 'loongarch-6.4' of ↵Linus Torvalds
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 Tang
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 Revest
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: Let unregister_ftrace_direct_multi() call ftrace_free_filter()Florent Revest
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: Include the nospec-branch.h only for x86Song Shuai
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>
2023-01-24ftrace: Export ftrace_free_filter() to modulesMark Rutland
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 Zijlstra
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 Zijlstra
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
2022-01-05ftrace/samples: Add missing prototypes direct functionsJiri Olsa
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 Olsa
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>