kernel/git/next/linux-next.git/samples/ftrace, branch master

samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify

2026-08-26T19:50:22+00:00

ftrace_direct_multi_init() assigns kthread_run()'s return value to simple_tsk without an IS_ERR() check. When kthread_run() fails it returns ERR_PTR(-ENOMEM), but init still returns 0, so the module loads with simple_tsk holding an error pointer. On unload, ftrace_direct_multi_exit() then passes that ERR_PTR to kthread_stop(), leading to a null-pointer-dereference. Check the return value of kthread_run() with IS_ERR(); on failure, unregister the ftrace direct call and propagate the error code. Link: https://patch.msgid.link/20260826015050.10772-1-vulab@iscas.ac.cn Fixes: e1067a07cfbc ("ftrace/samples: Add module to test multi direct modify interface") Suggested-by: Steven Rostedt Signed-off-by: Haotian Zhang Signed-off-by: Steven Rostedt

samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify

2026-08-26T19:49:15+00:00

ftrace_direct_init() assigns kthread_run()'s return value to simple_tsk without an IS_ERR() check. When kthread_run() fails it returns ERR_PTR(-ENOMEM), but init still returns 0, so the module loads with simple_tsk holding an error pointer. On unload, ftrace_direct_exit() then passes that ERR_PTR to kthread_stop(), leading to a null-pointer-dereference. Check the return value of kthread_run() with IS_ERR(); on failure, unregister the ftrace direct call and propagate the error code. Link: https://patch.msgid.link/20260826015034.10755-1-vulab@iscas.ac.cn Fixes: ae0cc3b7e7f5 ("ftrace/samples: Add a sample module that implements modify_ftrace_direct()") Suggested-by: Steven Rostedt Signed-off-by: Haotian Zhang Signed-off-by: Steven Rostedt

samples/ftrace: Prevent division by zero when nr_function_calls is zero

2026-07-28T11:18:50+00:00

The ftrace-ops sample exposes nr_function_calls as a module parameter and uses it as the divisor when printing the measured time per call. Loading the module with nr_function_calls=0 skips the benchmark loop and then divides the elapsed time by zero, crashing the kernel during sample module initialization. Keep accepting the parameter value, but report -1LL as the per-call duration when the call count is zero instead of dividing by it. Link: https://patch.msgid.link/20260629152616.107080.e19bfbed249c.ftrace-ops-zero-function-calls-div0@trailofbits.com Assisted-by: Codex:gpt-5.5-cyber-preview Signed-off-by: Samuel Moelius Signed-off-by: Steven Rostedt

samples: ftrace: Fix typos in benchmark comment

2026-07-07T14:42:28+00:00

Fix two typos in the ftrace operations sample benchmark comment. Link: https://patch.msgid.link/20260621095153.93762-1-pyudistira519@gmail.com Signed-off-by: Yudistira Putra Signed-off-by: Steven Rostedt

samples/ftrace: Adjust LoongArch register restore order in direct calls

2025-12-31T07:19:25+00:00

Ensure that in the ftrace direct call logic, the CPU register state (with ra = parent return address) is restored to the correct state after the execution of the custom trampoline function and before returning to the traced function. Additionally, guarantee the correctness of the jump logic for jr t0 (traced function address). Cc: stable@vger.kernel.org Fixes: 9cdc3b6a299c ("LoongArch: ftrace: Add direct call support") Reported-by: Youling Tang Acked-by: Steven Rostedt (Google) Signed-off-by: Chenghao Duan Signed-off-by: Huacai Chen

ftrace/samples: Fix function size computation

2025-09-05T22:39:12+00:00

In my_tramp1 function .size directive was placed above ASM_RET instruction, leading to a wrong function size. Link: https://lore.kernel.org/aK3d7vxNcO52kEmg@vova-pc Fixes: 9d907f1ae80b ("samples/ftrace: Fix asm function ELF annotations") Signed-off-by: Vladimir Riabchun Signed-off-by: Steven Rostedt (Google)

tracing: samples: Initialize trace_array_printk() with the correct function

2025-05-12T17:07:22+00:00

When using trace_array_printk() on a created instance, the correct function to use to initialize it is: trace_array_init_printk() Not trace_printk_init_buffer() The former is a proper function to use, the latter is for initializing trace_printk() and causes the NOTICE banner to be displayed. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Cc: Divya Indi Link: https://lore.kernel.org/20250509152657.0f6744d9@gandalf.local.home Fixes: 89ed42495ef4a ("tracing: Sample module to demonstrate kernel access to Ftrace instances.") Fixes: 38ce2a9e33db6 ("tracing: Add trace_array_init_printk() to initialize instance trace_printk() buffers") Signed-off-by: Steven Rostedt (Google)

treewide: Switch/rename to timer_delete[_sync]()

2025-04-05T08:30:12+00:00

timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree over and remove the historical wrapper inlines. Conversion was done with coccinelle plus manual fixups where necessary. Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar

samples/ftrace: Add support for ftrace direct samples on powerpc

2024-10-31T00:00:55+00:00

Add powerpc 32-bit and 64-bit samples for ftrace direct. This serves to show the sample instruction sequence to be used by ftrace direct calls to adhere to the ftrace ABI. On 64-bit powerpc, TOC setup requires some additional work. Signed-off-by: Naveen N Rao Signed-off-by: Michael Ellerman Link: https://patch.msgid.link/20241030070850.1361304-17-hbathini@linux.ibm.com

Merge tag 'riscv-for-linus-6.8-mw4' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

2024-01-20T19:06:04+00:00

Pull more RISC-V updates from Palmer Dabbelt: - Support for tuning for systems with fast misaligned accesses. - Support for SBI-based suspend. - Support for the new SBI debug console extension. - The T-Head CMOs now use PA-based flushes. - Support for enabling the V extension in kernel code. - Optimized IP checksum routines. - Various ftrace improvements. - Support for archrandom, which depends on the Zkr extension. - The build is no longer broken under NET=n, KUNIT=y for ports that don't define their own ipv6 checksum. * tag 'riscv-for-linus-6.8-mw4' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (56 commits) lib: checksum: Fix build with CONFIG_NET=n riscv: lib: Check if output in asm goto supported riscv: Fix build error on rv32 + XIP riscv: optimize ELF relocation function in riscv RISC-V: Implement archrandom when Zkr is available riscv: Optimize hweight API with Zbb extension riscv: add dependency among Image(.gz), loader(.bin), and vmlinuz.efi samples: ftrace: Add RISC-V support for SAMPLE_FTRACE_DIRECT[_MULTI] riscv: ftrace: Add DYNAMIC_FTRACE_WITH_DIRECT_CALLS support riscv: ftrace: Make function graph use ftrace directly riscv: select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY lib/Kconfig.debug: Update AS_HAS_NON_CONST_LEB128 comment and name riscv: Restrict DWARF5 when building with LLVM to known working versions riscv: Hoist linker relaxation disabling logic into Kconfig kunit: Add tests for csum_ipv6_magic and ip_fast_csum riscv: Add checksum library riscv: Add checksum header riscv: Add static key for misaligned accesses asm-generic: Improve csum_fold RISC-V: selftests: cbo: Ensure asm operands match constraints ...