kernel/linux.git/tools/tracing, branch v7.0-rc7

rtla: Fix build without libbpf header

2026-03-30T16:44:48+00:00

rtla supports building without libbpf. However, BPF actions patchset [1] adds an include of bpf/libbpf.h into timerlat_bpf.h, which breaks build on systems that don't have libbpf headers installed. This is a leftover from a draft version of the patchset where timerlat_bpf_set_action() (which takes a struct bpf_program * argument) was defined in the header. timerlat_bpf.c already includes bpf/libbpf.h via timerlat.skel.h when libbpf is present. Remove the redundant include to fix build on systems without libbpf headers. [1] https://lore.kernel.org/linux-trace-kernel/20251126144205.331954-1-tglozar@redhat.com/T/ Cc: John Kacur Cc: Luis Goncalves Cc: Crystal Wood Cc: Costa Shulyupin Link: https://patch.msgid.link/20260330091207.16184-1-tglozar@redhat.com Reported-by: Steven Rostedt (Google) Closes: https://lore.kernel.org/linux-trace-kernel/20260329122202.65a8b575@robin/ Fixes: 8cd0f08ac72e ("rtla/timerlat: Support tail call from BPF program") Signed-off-by: Tomas Glozar Reviewed-by: Wander Lairson Costa Signed-off-by: Steven Rostedt (Google)

rtla: Fix parse_cpu_set() bug introduced by strtoi()

2026-01-13T07:32:52+00:00

The patch 'Replace atoi() with a robust strtoi()' introduced a bug in parse_cpu_set(), which relies on partial parsing of the input string. The function parses CPU specifications like '0-3,5' by incrementing a pointer through the string. strtoi() rejects strings with trailing characters, causing parse_cpu_set() to fail on any CPU list with multiple entries. Restore the original use of atoi() in parse_cpu_set(). Fixes: 7e9dfccf8f11 ("rtla: Replace atoi() with a robust strtoi()") Signed-off-by: Costa Shulyupin Reviewed-by: Masami Hiramatsu (Google) Link: https://lore.kernel.org/r/20260112192642.212848-2-costa.shul@redhat.com Signed-off-by: Tomas Glozar

rtla: Fix parse_cpu_set() return value documentation

2026-01-07T14:57:56+00:00

Correct the return value documentation for parse_cpu_set() function in utils.c. The comment incorrectly stated that the function returns 1 on success and 0 on failure, but the actual implementation returns 0 on success and 1 on failure, following the common error-on-nonzero convention used throughout the codebase. This documentation fix ensures that developers reading the code understand the correct return value semantics and prevents potential misuse of the function's return value in conditional checks. Signed-off-by: Wander Lairson Costa Link: https://lore.kernel.org/r/20260106133655.249887-18-wander@redhat.com Signed-off-by: Tomas Glozar

rtla: Ensure null termination after read operations in utils.c

2026-01-07T14:57:56+00:00

Add explicit null termination and buffer initialization for read() operations in procfs_is_workload_pid() and get_self_cgroup() functions. The read() system call does not null-terminate the data it reads, and when the buffer is filled to capacity, subsequent string operations will read past the buffer boundary searching for a null terminator. In procfs_is_workload_pid(), explicitly set buffer[MAX_PATH-1] to '\0' to ensure the buffer is always null-terminated before passing it to strncmp(). In get_self_cgroup(), use memset() to zero the path buffer before reading, which ensures null termination when retval is less than MAX_PATH. Additionally, set path[MAX_PATH-1] to '\0' after the read to handle the case where the buffer is filled completely. These defensive buffer handling practices prevent potential buffer overruns and align with the ongoing buffer safety improvements across the rtla codebase. Signed-off-by: Wander Lairson Costa Link: https://lore.kernel.org/r/20260106133655.249887-17-wander@redhat.com Signed-off-by: Tomas Glozar

rtla: Make stop_tracing variable volatile

2026-01-07T14:57:55+00:00

The stop_tracing global variable is accessed from both the signal handler context and the main program flow without synchronization. This creates a potential race condition where compiler optimizations could cache the variable value in registers, preventing the signal handler's updates from being visible to other parts of the program. Add the volatile qualifier to stop_tracing in both common.c and common.h to ensure all accesses to this variable bypass compiler optimizations and read directly from memory. This guarantees that when the signal handler sets stop_tracing, the change is immediately visible to the main program loop, preventing potential hangs or delayed shutdown when termination signals are received. Signed-off-by: Wander Lairson Costa Link: https://lore.kernel.org/r/20260106133655.249887-16-wander@redhat.com Signed-off-by: Tomas Glozar

rtla: Add generated output files to gitignore

2026-01-07T14:57:55+00:00

The rtla tool generates various output files during testing and execution, including custom trace outputs and histogram data. These files are artifacts of running the tool with different options and should not be tracked in version control. Add gitignore entries for custom_filename.txt, osnoise_irq_noise_hist.txt, osnoise_trace.txt, and timerlat_trace.txt to prevent accidentally committing these generated files. This aligns with the existing pattern of ignoring build artifacts and generated headers like *.skel.h. Signed-off-by: Wander Lairson Costa Link: https://lore.kernel.org/r/20260106133655.249887-15-wander@redhat.com Signed-off-by: Tomas Glozar

rtla: Fix NULL pointer dereference in actions_parse

2026-01-07T14:57:55+00:00

The actions_parse() function uses strtok() to tokenize the trigger string, but does not check if the returned token is NULL before passing it to strcmp(). If the trigger parameter is an empty string or contains only delimiter characters, strtok() returns NULL, causing strcmp() to dereference a NULL pointer and crash the program. This issue can be triggered by malformed user input or edge cases in trigger string parsing. Add a NULL check immediately after the strtok() call to validate that a token was successfully extracted before using it. If no token is found, the function now returns -1 to indicate a parsing error. Signed-off-by: Wander Lairson Costa Link: https://lore.kernel.org/r/20260106133655.249887-13-wander@redhat.com Signed-off-by: Tomas Glozar

rtla: Remove unused headers

2026-01-07T14:57:55+00:00

Remove unused includes for and to clean up the code and reduce unnecessary dependencies. Signed-off-by: Wander Lairson Costa Link: https://lore.kernel.org/r/20260106133655.249887-12-wander@redhat.com Signed-off-by: Tomas Glozar

rtla: Remove redundant memset after calloc

2026-01-07T14:57:55+00:00

The actions struct is allocated using calloc, which already returns zeroed memory. The subsequent memset call to zero the 'present' member is therefore redundant. Signed-off-by: Wander Lairson Costa Link: https://lore.kernel.org/r/20260106133655.249887-10-wander@redhat.com Signed-off-by: Tomas Glozar

rtla: Use standard exit codes for result enum

2026-01-07T14:57:55+00:00

The result enum defines custom values for PASSED, ERROR, and FAILED. These values correspond to standard exit codes EXIT_SUCCESS and EXIT_FAILURE. Update the enum to use the standard macros EXIT_SUCCESS and EXIT_FAILURE to improve readability and adherence to standard C practices. The FAILED value is implicitly assigned EXIT_FAILURE + 1, so there is no need to assign an explicit value. Signed-off-by: Wander Lairson Costa Link: https://lore.kernel.org/r/20260106133655.249887-9-wander@redhat.com Signed-off-by: Tomas Glozar