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2024-11-21Merge tag 'bpf-next-6.13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Pull bpf updates from Alexei Starovoitov: - Add BPF uprobe session support (Jiri Olsa) - Optimize uprobe performance (Andrii Nakryiko) - Add bpf_fastcall support to helpers and kfuncs (Eduard Zingerman) - Avoid calling free_htab_elem() under hash map bucket lock (Hou Tao) - Prevent tailcall infinite loop caused by freplace (Leon Hwang) - Mark raw_tracepoint arguments as nullable (Kumar Kartikeya Dwivedi) - Introduce uptr support in the task local storage map (Martin KaFai Lau) - Stringify errno log messages in libbpf (Mykyta Yatsenko) - Add kmem_cache BPF iterator for perf's lock profiling (Namhyung Kim) - Support BPF objects of either endianness in libbpf (Tony Ambardar) - Add ksym to struct_ops trampoline to fix stack trace (Xu Kuohai) - Introduce private stack for eligible BPF programs (Yonghong Song) - Migrate samples/bpf tests to selftests/bpf test_progs (Daniel T. Lee) - Migrate test_sock to selftests/bpf test_progs (Jordan Rife) * tag 'bpf-next-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (152 commits) libbpf: Change hash_combine parameters from long to unsigned long selftests/bpf: Fix build error with llvm 19 libbpf: Fix memory leak in bpf_program__attach_uprobe_multi bpf: use common instruction history across all states bpf: Add necessary migrate_disable to range_tree. bpf: Do not alloc arena on unsupported arches selftests/bpf: Set test path for token/obj_priv_implicit_token_envvar selftests/bpf: Add a test for arena range tree algorithm bpf: Introduce range_tree data structure and use it in bpf arena samples/bpf: Remove unused variable in xdp2skb_meta_kern.c samples/bpf: Remove unused variables in tc_l2_redirect_kern.c bpftool: Cast variable `var` to long long bpf, x86: Propagate tailcall info only for subprogs bpf: Add kernel symbol for struct_ops trampoline bpf: Use function pointers count as struct_ops links count bpf: Remove unused member rcu from bpf_struct_ops_map selftests/bpf: Add struct_ops prog private stack tests bpf: Support private stack for struct_ops progs selftests/bpf: Add tracing prog private stack tests bpf, x86: Support private stack in jit ...
2024-11-20Merge tag 'kgdb-6.13-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux Pull kgdb updates from Daniel Thompson: "A relatively modest collection of changes: - Adopt kstrtoint() and kstrtol() instead of the simple_strtoXX family for better error checking of user input. - Align the print behavour when breakpoints are enabled and disabled by adopting the current behaviour of breakpoint disable for both. - Remove some of the (rather odd and user hostile) hex fallbacks and require kdb users to prefix with 0x instead. - Tidy up (and fix) control code handling in kdb's keyboard code. This makes the control code handling at the keyboard behave the same way as it does via the UART. - Switch my own entry in MAINTAINERS to my @kernel.org address" * tag 'kgdb-6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux: kdb: fix ctrl+e/a/f/b/d/p/n broken in keyboard mode MAINTAINERS: Use Daniel Thompson's korg address for kgdb work kdb: Fix breakpoint enable to be silent if already enabled kdb: Remove fallback interpretation of arbitrary numbers as hex trace: kdb: Replace simple_strtoul with kstrtoul in kdb_ftdump kdb: Replace the use of simple_strto with safer kstrto in kdb_main
2024-11-20Merge tag 'ftrace-v6.13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull ftrace updates from Steven Rostedt: - Restructure the function graph shadow stack to prepare it for use with kretprobes With the goal of merging the shadow stack logic of function graph and kretprobes, some more restructuring of the function shadow stack is required. Move out function graph specific fields from the fgraph infrastructure and store it on the new stack variables that can pass data from the entry callback to the exit callback. Hopefully, with this change, the merge of kretprobes to use fgraph shadow stacks will be ready by the next merge window. - Make shadow stack 4k instead of using PAGE_SIZE. Some architectures have very large PAGE_SIZE values which make its use for shadow stacks waste a lot of memory. - Give shadow stacks its own kmem cache. When function graph is started, every task on the system gets a shadow stack. In the future, shadow stacks may not be 4K in size. Have it have its own kmem cache so that whatever size it becomes will still be efficient in allocations. - Initialize profiler graph ops as it will be needed for new updates to fgraph - Convert to use guard(mutex) for several ftrace and fgraph functions - Add more comments and documentation - Show function return address in function graph tracer Add an option to show the caller of a function at each entry of the function graph tracer, similar to what the function tracer does. - Abstract out ftrace_regs from being used directly like pt_regs ftrace_regs was created to store a partial pt_regs. It holds only the registers and stack information to get to the function arguments and return values. On several archs, it is simply a wrapper around pt_regs. But some users would access ftrace_regs directly to get the pt_regs which will not work on all archs. Make ftrace_regs an abstract structure that requires all access to its fields be through accessor functions. - Show how long it takes to do function code modifications When code modification for function hooks happen, it always had the time recorded in how long it took to do the conversion. But this value was never exported. Recently the code was touched due to new ROX modification handling that caused a large slow down in doing the modifications and had a significant impact on boot times. Expose the timings in the dyn_ftrace_total_info file. This file was created a while ago to show information about memory usage and such to implement dynamic function tracing. It's also an appropriate file to store the timings of this modification as well. This will make it easier to see the impact of changes to code modification on boot up timings. - Other clean ups and small fixes * tag 'ftrace-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (22 commits) ftrace: Show timings of how long nop patching took ftrace: Use guard to take ftrace_lock in ftrace_graph_set_hash() ftrace: Use guard to take the ftrace_lock in release_probe() ftrace: Use guard to lock ftrace_lock in cache_mod() ftrace: Use guard for match_records() fgraph: Use guard(mutex)(&ftrace_lock) for unregister_ftrace_graph() fgraph: Give ret_stack its own kmem cache fgraph: Separate size of ret_stack from PAGE_SIZE ftrace: Rename ftrace_regs_return_value to ftrace_regs_get_return_value selftests/ftrace: Fix check of return value in fgraph-retval.tc test ftrace: Use arch_ftrace_regs() for ftrace_regs_*() macros ftrace: Consolidate ftrace_regs accessor functions for archs using pt_regs ftrace: Make ftrace_regs abstract from direct use fgragh: No need to invoke the function call_filter_check_discard() fgraph: Simplify return address printing in function graph tracer function_graph: Remove unnecessary initialization in ftrace_graph_ret_addr() function_graph: Support recording and printing the function return address ftrace: Have calltime be saved in the fgraph storage ftrace: Use a running sleeptime instead of saving on shadow stack fgraph: Use fgraph data to store subtime for profiler ...
2024-11-19Merge tag 'perf-core-2024-11-18' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull performance events updates from Ingo Molnar: "Uprobes: - Add BPF session support (Jiri Olsa) - Switch to RCU Tasks Trace flavor for better performance (Andrii Nakryiko) - Massively increase uretprobe SMP scalability by SRCU-protecting the uretprobe lifetime (Andrii Nakryiko) - Kill xol_area->slot_count (Oleg Nesterov) Core facilities: - Implement targeted high-frequency profiling by adding the ability for an event to "pause" or "resume" AUX area tracing (Adrian Hunter) VM profiling/sampling: - Correct perf sampling with guest VMs (Colton Lewis) New hardware support: - x86/intel: Add PMU support for Intel ArrowLake-H CPUs (Dapeng Mi) Misc fixes and enhancements: - x86/intel/pt: Fix buffer full but size is 0 case (Adrian Hunter) - x86/amd: Warn only on new bits set (Breno Leitao) - x86/amd/uncore: Avoid a false positive warning about snprintf truncation in amd_uncore_umc_ctx_init (Jean Delvare) - uprobes: Re-order struct uprobe_task to save some space (Christophe JAILLET) - x86/rapl: Move the pmu allocation out of CPU hotplug (Kan Liang) - x86/rapl: Clean up cpumask and hotplug (Kan Liang) - uprobes: Deuglify xol_get_insn_slot/xol_free_insn_slot paths (Oleg Nesterov)" * tag 'perf-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits) perf/core: Correct perf sampling with guest VMs perf/x86: Refactor misc flag assignments perf/powerpc: Use perf_arch_instruction_pointer() perf/core: Hoist perf_instruction_pointer() and perf_misc_flags() perf/arm: Drop unused functions uprobes: Re-order struct uprobe_task to save some space perf/x86/amd/uncore: Avoid a false positive warning about snprintf truncation in amd_uncore_umc_ctx_init perf/x86/intel: Do not enable large PEBS for events with aux actions or aux sampling perf/x86/intel/pt: Add support for pause / resume perf/core: Add aux_pause, aux_resume, aux_start_paused perf/x86/intel/pt: Fix buffer full but size is 0 case uprobes: SRCU-protect uretprobe lifetime (with timeout) uprobes: allow put_uprobe() from non-sleepable softirq context perf/x86/rapl: Clean up cpumask and hotplug perf/x86/rapl: Move the pmu allocation out of CPU hotplug uprobe: Add support for session consumer uprobe: Add data pointer to consumer handlers perf/x86/amd: Warn only on new bits set uprobes: fold xol_take_insn_slot() into xol_get_insn_slot() uprobes: kill xol_area->slot_count ...
2024-11-16Merge tag 'trace-ringbuffer-v6.12-rc7-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull ring buffer fixes from Steven Rostedt: - Revert: "ring-buffer: Do not have boot mapped buffers hook to CPU hotplug" A crash that happened on cpu hotplug was actually caused by the incorrect ref counting that was fixed by commit 2cf9733891a4 ("ring-buffer: Fix refcount setting of boot mapped buffers"). The removal of calling cpu hotplug callbacks on memory mapped buffers was not an issue even though the tests at the time pointed toward it. But in fact, there's a check in that code that tests to see if the buffers are already allocated or not, and will not allocate them again if they are. Not calling the cpu hotplug callbacks ended up not initializing the non boot CPU buffers. Simply remove that change. - Clear all CPU buffers when starting tracing in a boot mapped buffer To properly process events from a previous boot, the address space needs to be accounted for due to KASLR and the events in the buffer are updated accordingly when read. This also requires that when the buffer has tracing enabled again in the current boot that the buffers are reset so that events from the previous boot do not interact with the events of the current boot and cause confusing due to not having the proper meta data. It was found that if a CPU is taken offline, that its per CPU buffer is not reset when tracing starts. This allows for events to be from both the previous boot and the current boot to be in the buffer at the same time. Clear all CPU buffers when tracing is started in a boot mapped buffer. * tag 'trace-ringbuffer-v6.12-rc7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing/ring-buffer: Clear all memory mapped CPU ring buffers on first recording Revert: "ring-buffer: Do not have boot mapped buffers hook to CPU hotplug"
2024-11-14tracing/ring-buffer: Clear all memory mapped CPU ring buffers on first recordingSteven Rostedt
The events of a memory mapped ring buffer from the previous boot should not be mixed in with events from the current boot. There's meta data that is used to handle KASLR so that function names can be shown properly. Also, since the timestamps of the previous boot have no meaning to the timestamps of the current boot, having them intermingled in a buffer can also cause confusion because there could possibly be events in the future. When a trace is activated the meta data is reset so that the pointers of are now processed for the new address space. The trace buffers are reset when tracing starts for the first time. The problem here is that the reset only happens on online CPUs. If a CPU is offline, it does not get reset. To demonstrate the issue, a previous boot had tracing enabled in the boot mapped ring buffer on reboot. On the following boot, tracing has not been started yet so the function trace from the previous boot is still visible. # trace-cmd show -B boot_mapped -c 3 | tail <idle>-0 [003] d.h2. 156.462395: __rcu_read_lock <-cpu_emergency_disable_virtualization <idle>-0 [003] d.h2. 156.462396: vmx_emergency_disable_virtualization_cpu <-cpu_emergency_disable_virtualization <idle>-0 [003] d.h2. 156.462396: __rcu_read_unlock <-__sysvec_reboot <idle>-0 [003] d.h2. 156.462397: stop_this_cpu <-__sysvec_reboot <idle>-0 [003] d.h2. 156.462397: set_cpu_online <-stop_this_cpu <idle>-0 [003] d.h2. 156.462397: disable_local_APIC <-stop_this_cpu <idle>-0 [003] d.h2. 156.462398: clear_local_APIC <-disable_local_APIC <idle>-0 [003] d.h2. 156.462574: mcheck_cpu_clear <-stop_this_cpu <idle>-0 [003] d.h2. 156.462575: mce_intel_feature_clear <-stop_this_cpu <idle>-0 [003] d.h2. 156.462575: lmce_supported <-mce_intel_feature_clear Now, if CPU 3 is taken offline, and tracing is started on the memory mapped ring buffer, the events from the previous boot in the CPU 3 ring buffer is not reset. Now those events are using the meta data from the current boot and produces just hex values. # echo 0 > /sys/devices/system/cpu/cpu3/online # trace-cmd start -B boot_mapped -p function # trace-cmd show -B boot_mapped -c 3 | tail <idle>-0 [003] d.h2. 156.462395: 0xffffffff9a1e3194 <-0xffffffff9a0f655e <idle>-0 [003] d.h2. 156.462396: 0xffffffff9a0a1d24 <-0xffffffff9a0f656f <idle>-0 [003] d.h2. 156.462396: 0xffffffff9a1e6bc4 <-0xffffffff9a0f7323 <idle>-0 [003] d.h2. 156.462397: 0xffffffff9a0d12b4 <-0xffffffff9a0f732a <idle>-0 [003] d.h2. 156.462397: 0xffffffff9a1458d4 <-0xffffffff9a0d12e2 <idle>-0 [003] d.h2. 156.462397: 0xffffffff9a0faed4 <-0xffffffff9a0d12e7 <idle>-0 [003] d.h2. 156.462398: 0xffffffff9a0faaf4 <-0xffffffff9a0faef2 <idle>-0 [003] d.h2. 156.462574: 0xffffffff9a0e3444 <-0xffffffff9a0d12ef <idle>-0 [003] d.h2. 156.462575: 0xffffffff9a0e4964 <-0xffffffff9a0d12ef <idle>-0 [003] d.h2. 156.462575: 0xffffffff9a0e3fb0 <-0xffffffff9a0e496f Reset all CPUs when starting a boot mapped ring buffer for the first time, and not just the online CPUs. Fixes: 7a1d1e4b9639f ("tracing/ring-buffer: Add last_boot_info file to boot instance") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-14Revert: "ring-buffer: Do not have boot mapped buffers hook to CPU hotplug"Steven Rostedt
A crash happened when testing cpu hotplug with respect to the memory mapped ring buffers. It was assumed that the hot plug code was adding a per CPU buffer that was already created that caused the crash. The real problem was due to ref counting and was fixed by commit 2cf9733891a4 ("ring-buffer: Fix refcount setting of boot mapped buffers"). When a per CPU buffer is created, it will not be created again even with CPU hotplug, so the fix to not use CPU hotplug was a red herring. In fact, it caused only the boot CPU buffer to be created, leaving the other CPU per CPU buffers disabled. Revert that change as it was not the culprit of the fix it was intended to be. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20241113230839.6c03640f@gandalf.local.home Fixes: 912da2c384d5 ("ring-buffer: Do not have boot mapped buffers hook to CPU hotplug") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-13Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfAlexei Starovoitov
Cross-merge bpf fixes after downstream PR. In particular to bring the fix in commit aa30eb3260b2 ("bpf: Force checkpoint when jmp history is too long"). The follow up verifier work depends on it. And the fix in commit 6801cf7890f2 ("selftests/bpf: Use -4095 as the bad address for bits iterator"). It's fixing instability of BPF CI on s390 arch. No conflicts. Adjacent changes in: Auto-merging arch/Kconfig Auto-merging kernel/bpf/helpers.c Auto-merging kernel/bpf/memalloc.c Auto-merging kernel/bpf/verifier.c Auto-merging mm/slab_common.c Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-11-11bpf: Add support for uprobe multi session contextJiri Olsa
Placing bpf_session_run_ctx layer in between bpf_run_ctx and bpf_uprobe_multi_run_ctx, so the session data can be retrieved from uprobe_multi link. Plus granting session kfuncs access to uprobe session programs. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241108134544.480660-5-jolsa@kernel.org
2024-11-11bpf: Add support for uprobe multi session attachJiri Olsa
Adding support to attach BPF program for entry and return probe of the same function. This is common use case which at the moment requires to create two uprobe multi links. Adding new BPF_TRACE_UPROBE_SESSION attach type that instructs kernel to attach single link program to both entry and exit probe. It's possible to control execution of the BPF program on return probe simply by returning zero or non zero from the entry BPF program execution to execute or not the BPF program on return probe respectively. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241108134544.480660-4-jolsa@kernel.org
2024-11-11bpf: Force uprobe bpf program to always return 0Jiri Olsa
As suggested by Andrii make uprobe multi bpf programs to always return 0, so they can't force uprobe removal. Keeping the int return type for uprobe_prog_run, because it will be used in following session changes. Fixes: 89ae89f53d20 ("bpf: Add multi uprobe link") Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241108134544.480660-3-jolsa@kernel.org
2024-11-06Merge tag 'perf-core-for-bpf-next' from tip treeAndrii Nakryiko
Stable tag for bpf-next's uprobe work. Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2024-11-02trace: kdb: Replace simple_strtoul with kstrtoul in kdb_ftdumpYuran Pereira
The function simple_strtoul performs no error checking in scenarios where the input value overflows the intended output variable. This results in this function successfully returning, even when the output does not match the input string (aka the function returns successfully even when the result is wrong). Or as it was mentioned [1], "...simple_strtol(), simple_strtoll(), simple_strtoul(), and simple_strtoull() functions explicitly ignore overflows, which may lead to unexpected results in callers." Hence, the use of those functions is discouraged. This patch replaces all uses of the simple_strtoul with the safer alternatives kstrtoint and kstrtol. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#simple-strtol-simple-strtoll-simple-strtoul-simple-strtoull Signed-off-by: Yuran Pereira <yuran.pereira@hotmail.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> [nir: style fixes] Signed-off-by: Nir Lichtman <nir@lichtman.org> Link: https://lore.kernel.org/r/20241028192100.GB918454@lichtman.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
2024-11-01tracing: Document tracefs gid mount optionKalesh Singh
Commit ee7f3666995d ("tracefs: Have new files inherit the ownership of their parent") and commit 48b27b6b5191 ("tracefs: Set all files to the same group ownership as the mount option") introduced a new gid mount option that allows specifying a group to apply to all entries in tracefs. Document this in the tracing readme. Cc: Eric Sandeen <sandeen@redhat.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Ali Zahraee <ahzahraee@gmail.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Link: https://lore.kernel.org/20241030171928.4168869-3-kaleshsingh@google.com Signed-off-by: Kalesh Singh <kaleshsingh@google.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-30ftrace: Show timings of how long nop patching tookSteven Rostedt
Since the beginning of ftrace, the code that did the patching had its timings saved on how long it took to complete. But this information was never exposed. It was used for debugging and exposing it was always something that was on the TODO list. Now it's time to expose it. There's even a file that is where it should go! Also include how long patching modules took as a separate value. # cat /sys/kernel/tracing/dyn_ftrace_total_info 57680 pages:231 groups: 9 ftrace boot update time = 14024666 (ns) ftrace module total update time = 126070 (ns) Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/20241017113105.1edfa943@gandalf.local.home Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-29ftrace: Use guard to take ftrace_lock in ftrace_graph_set_hash()Steven Rostedt
The ftrace_lock is taken for most of the ftrace_graph_set_hash() function throughout the end. Use guard to take the ftrace_lock to simplify the exit paths. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/20241028071308.406073025@goodmis.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-29ftrace: Use guard to take the ftrace_lock in release_probe()Steven Rostedt
The ftrace_lock is held throughout the entire release_probe() function. Use guard to simplify any exit paths. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/20241028071308.250787901@goodmis.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-29ftrace: Use guard to lock ftrace_lock in cache_mod()Steven Rostedt
The ftrace_lock is held throughout cache_mod(), use guard to simplify the error paths. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/20241028071308.088458856@goodmis.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-29ftrace: Use guard for match_records()Steven Rostedt
The ftrace_lock is held for most of match_records() until the end of the function. Use guard to make error paths simpler. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/20241028071307.927146604@goodmis.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-29fgraph: Use guard(mutex)(&ftrace_lock) for unregister_ftrace_graph()Steven Rostedt
The ftrace_lock is held throughout unregister_ftrace_graph(), use a guard to simplify the error paths. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/20241028071307.770550792@goodmis.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-29fgraph: Give ret_stack its own kmem cacheSteven Rostedt
The ret_stack (shadow stack used by function graph infrastructure) is created for every task on the system when function graph is enabled. Give it its own kmem_cache. This will make it easier to see how much memory is being used specifically for function graph shadow stacks. In the future, this size may change and may not be a power of two. Having its own cache can also keep it from fragmenting memory. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Link: https://lore.kernel.org/20241026063210.7d4910a7@rorschach.local.home Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-29fgraph: Separate size of ret_stack from PAGE_SIZESteven Rostedt
The ret_stack (shadow stack used by function graph infrastructure) is currently defined as PAGE_SIZE. But some architectures which have 64K PAGE_SIZE, this is way overkill. Also there's an effort to allow the PAGE_SIZE to be defined at boot up. Hard code it for now to 4096. In the future, this size may change and even be dependent on specific architectures. Link: https://lore.kernel.org/all/e5067bb8-0fcd-4739-9bca-0e872037d5a1@arm.com/ Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20241019152951.053f9646@rorschach.local.home Suggested-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-29Merge tag 'ftrace-v6.12-rc4' into trace/ftrace/coreSteven Rostedt
In order to modify the code that allocates the shadow stacks, merge the changes that fixed the CPU hotplug shadow stack allocations and build on top of that. Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-27Merge tag 'ftrace-v6.12-rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull ftrace fixes from Steven Rostedt: - Fix missing mutex unlock in error path of register_ftrace_graph() A previous fix added a return on an error path and forgot to unlock the mutex. Instead of dealing with error paths, use guard(mutex) as the mutex is just released at the exit of the function anyway. Other functions in this file should be updated with this, but that's a cleanup and not a fix. - Change cpuhp setup name to be consistent with other cpuhp states The same fix that the above patch fixes added a cpuhp_setup_state() call with the name of "fgraph_idle_init". I was informed that it should instead be something like: "fgraph:online". Update that too. * tag 'ftrace-v6.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: fgraph: Change the name of cpuhp state to "fgraph:online" fgraph: Fix missing unlock in register_ftrace_graph()
2024-10-24fgraph: Change the name of cpuhp state to "fgraph:online"Steven Rostedt
The cpuhp state name given to cpuhp_setup_state() is "fgraph_idle_init" which doesn't really conform to the names that are used for cpu hotplug setups. Instead rename it to "fgraph:online" to be in line with other states. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/20241024222944.473d88c5@rorschach.local.home Suggested-by: Masami Hiramatsu <mhiramat@kernel.org> Fixes: 2c02f7375e658 ("fgraph: Use CPU hotplug mechanism to initialize idle shadow stacks") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-24fgraph: Fix missing unlock in register_ftrace_graph()Li Huafei
Use guard(mutex)() to acquire and automatically release ftrace_lock, fixing the issue of not unlocking when calling cpuhp_setup_state() fails. Fixes smatch warning: kernel/trace/fgraph.c:1317 register_ftrace_graph() warn: inconsistent returns '&ftrace_lock'. Link: https://lore.kernel.org/20241024155917.1019580-1-lihuafei1@huawei.com Fixes: 2c02f7375e65 ("fgraph: Use CPU hotplug mechanism to initialize idle shadow stacks") Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Closes: https://lore.kernel.org/r/202410220121.wxg0olfd-lkp@intel.com/ Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Li Huafei <lihuafei1@huawei.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfAlexei Starovoitov
Cross-merge bpf fixes after downstream PR. No conflicts. Adjacent changes in: include/linux/bpf.h include/uapi/linux/bpf.h kernel/bpf/btf.c kernel/bpf/helpers.c kernel/bpf/syscall.c kernel/bpf/verifier.c kernel/trace/bpf_trace.c mm/slab_common.c tools/include/uapi/linux/bpf.h tools/testing/selftests/bpf/Makefile Link: https://lore.kernel.org/all/20241024215724.60017-1-daniel@iogearbox.net/ Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-24Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfLinus Torvalds
Pull bpf fixes from Daniel Borkmann: - Fix an out-of-bounds read in bpf_link_show_fdinfo for BPF sockmap link file descriptors (Hou Tao) - Fix BPF arm64 JIT's address emission with tag-based KASAN enabled reserving not enough size (Peter Collingbourne) - Fix BPF verifier do_misc_fixups patching for inlining of the bpf_get_branch_snapshot BPF helper (Andrii Nakryiko) - Fix a BPF verifier bug and reject BPF program write attempts into read-only marked BPF maps (Daniel Borkmann) - Fix perf_event_detach_bpf_prog error handling by removing an invalid check which would skip BPF program release (Jiri Olsa) - Fix memory leak when parsing mount options for the BPF filesystem (Hou Tao) * tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: bpf: Check validity of link->type in bpf_link_show_fdinfo() bpf: Add the missing BPF_LINK_TYPE invocation for sockmap bpf: fix do_misc_fixups() for bpf_get_branch_snapshot() bpf,perf: Fix perf_event_detach_bpf_prog error handling selftests/bpf: Add test for passing in uninit mtu_len selftests/bpf: Add test for writes to .rodata bpf: Remove MEM_UNINIT from skb/xdp MTU helpers bpf: Fix overloading of MEM_UNINIT's meaning bpf: Add MEM_WRITE attribute bpf: Preserve param->string when parsing mount options bpf, arm64: Fix address emission with tag-based KASAN enabled
2024-10-23bpf,perf: Fix perf_event_detach_bpf_prog error handlingJiri Olsa
Peter reported that perf_event_detach_bpf_prog might skip to release the bpf program for -ENOENT error from bpf_prog_array_copy. This can't happen because bpf program is stored in perf event and is detached and released only when perf event is freed. Let's drop the -ENOENT check and make sure the bpf program is released in any case. Fixes: 170a7e3ea070 ("bpf: bpf_prog_array_copy() should return -ENOENT if exclude_prog not found") Reported-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241023200352.3488610-1-jolsa@kernel.org Closes: https://lore.kernel.org/lkml/20241022111638.GC16066@noisy.programming.kicks-ass.net/
2024-10-23uprobe: Add data pointer to consumer handlersJiri Olsa
Adding data pointer to both entry and exit consumer handlers and all its users. The functionality itself is coming in following change. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20241018202252.693462-2-jolsa@kernel.org
2024-10-23tracing: Consider the NULL character when validating the event lengthLeo Yan
strlen() returns a string length excluding the null byte. If the string length equals to the maximum buffer length, the buffer will have no space for the NULL terminating character. This commit checks this condition and returns failure for it. Link: https://lore.kernel.org/all/20241007144724.920954-1-leo.yan@arm.com/ Fixes: dec65d79fd26 ("tracing/probe: Check event name length correctly") Signed-off-by: Leo Yan <leo.yan@arm.com> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-10-23tracing/probes: Fix MAX_TRACE_ARGS limit handlingMikel Rychliski
When creating a trace_probe we would set nr_args prior to truncating the arguments to MAX_TRACE_ARGS. However, we would only initialize arguments up to the limit. This caused invalid memory access when attempting to set up probes with more than 128 fetchargs. BUG: kernel NULL pointer dereference, address: 0000000000000020 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] PREEMPT SMP PTI CPU: 0 UID: 0 PID: 1769 Comm: cat Not tainted 6.11.0-rc7+ #8 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-1.fc39 04/01/2014 RIP: 0010:__set_print_fmt+0x134/0x330 Resolve the issue by applying the MAX_TRACE_ARGS limit earlier. Return an error when there are too many arguments instead of silently truncating. Link: https://lore.kernel.org/all/20240930202656.292869-1-mikel@mikelr.com/ Fixes: 035ba76014c0 ("tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_init") Signed-off-by: Mikel Rychliski <mikel@mikelr.com> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-10-22bpf: Add MEM_WRITE attributeDaniel Borkmann
Add a MEM_WRITE attribute for BPF helper functions which can be used in bpf_func_proto to annotate an argument type in order to let the verifier know that the helper writes into the memory passed as an argument. In the past MEM_UNINIT has been (ab)used for this function, but the latter merely tells the verifier that the passed memory can be uninitialized. There have been bugs with overloading the latter but aside from that there are also cases where the passed memory is read + written which currently cannot be expressed, see also 4b3786a6c539 ("bpf: Zero former ARG_PTR_TO_{LONG,INT} args in case of error"). Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20241021152809.33343-1-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-21bpf: Implement bpf_send_signal_task() kfuncPuranjay Mohan
Implement bpf_send_signal_task kfunc that is similar to bpf_send_signal_thread and bpf_send_signal helpers but can be used to send signals to other threads and processes. It also supports sending a cookie with the signal similar to sigqueue(). If the receiving process establishes a handler for the signal using the SA_SIGINFO flag to sigaction(), then it can obtain this cookie via the si_value field of the siginfo_t structure passed as the second argument to the handler. Signed-off-by: Puranjay Mohan <puranjay@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241016084136.10305-2-puranjay@kernel.org
2024-10-21uprobe: avoid out-of-bounds memory access of fetching argsQiao Ma
Uprobe needs to fetch args into a percpu buffer, and then copy to ring buffer to avoid non-atomic context problem. Sometimes user-space strings, arrays can be very large, but the size of percpu buffer is only page size. And store_trace_args() won't check whether these data exceeds a single page or not, caused out-of-bounds memory access. It could be reproduced by following steps: 1. build kernel with CONFIG_KASAN enabled 2. save follow program as test.c ``` \#include <stdio.h> \#include <stdlib.h> \#include <string.h> // If string length large than MAX_STRING_SIZE, the fetch_store_strlen() // will return 0, cause __get_data_size() return shorter size, and // store_trace_args() will not trigger out-of-bounds access. // So make string length less than 4096. \#define STRLEN 4093 void generate_string(char *str, int n) { int i; for (i = 0; i < n; ++i) { char c = i % 26 + 'a'; str[i] = c; } str[n-1] = '\0'; } void print_string(char *str) { printf("%s\n", str); } int main() { char tmp[STRLEN]; generate_string(tmp, STRLEN); print_string(tmp); return 0; } ``` 3. compile program `gcc -o test test.c` 4. get the offset of `print_string()` ``` objdump -t test | grep -w print_string 0000000000401199 g F .text 000000000000001b print_string ``` 5. configure uprobe with offset 0x1199 ``` off=0x1199 cd /sys/kernel/debug/tracing/ echo "p /root/test:${off} arg1=+0(%di):ustring arg2=\$comm arg3=+0(%di):ustring" > uprobe_events echo 1 > events/uprobes/enable echo 1 > tracing_on ``` 6. run `test`, and kasan will report error. ================================================================== BUG: KASAN: use-after-free in strncpy_from_user+0x1d6/0x1f0 Write of size 8 at addr ffff88812311c004 by task test/499CPU: 0 UID: 0 PID: 499 Comm: test Not tainted 6.12.0-rc3+ #18 Hardware name: Red Hat KVM, BIOS 1.16.0-4.al8 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x55/0x70 print_address_description.constprop.0+0x27/0x310 kasan_report+0x10f/0x120 ? strncpy_from_user+0x1d6/0x1f0 strncpy_from_user+0x1d6/0x1f0 ? rmqueue.constprop.0+0x70d/0x2ad0 process_fetch_insn+0xb26/0x1470 ? __pfx_process_fetch_insn+0x10/0x10 ? _raw_spin_lock+0x85/0xe0 ? __pfx__raw_spin_lock+0x10/0x10 ? __pte_offset_map+0x1f/0x2d0 ? unwind_next_frame+0xc5f/0x1f80 ? arch_stack_walk+0x68/0xf0 ? is_bpf_text_address+0x23/0x30 ? kernel_text_address.part.0+0xbb/0xd0 ? __kernel_text_address+0x66/0xb0 ? unwind_get_return_address+0x5e/0xa0 ? __pfx_stack_trace_consume_entry+0x10/0x10 ? arch_stack_walk+0xa2/0xf0 ? _raw_spin_lock_irqsave+0x8b/0xf0 ? __pfx__raw_spin_lock_irqsave+0x10/0x10 ? depot_alloc_stack+0x4c/0x1f0 ? _raw_spin_unlock_irqrestore+0xe/0x30 ? stack_depot_save_flags+0x35d/0x4f0 ? kasan_save_stack+0x34/0x50 ? kasan_save_stack+0x24/0x50 ? mutex_lock+0x91/0xe0 ? __pfx_mutex_lock+0x10/0x10 prepare_uprobe_buffer.part.0+0x2cd/0x500 uprobe_dispatcher+0x2c3/0x6a0 ? __pfx_uprobe_dispatcher+0x10/0x10 ? __kasan_slab_alloc+0x4d/0x90 handler_chain+0xdd/0x3e0 handle_swbp+0x26e/0x3d0 ? __pfx_handle_swbp+0x10/0x10 ? uprobe_pre_sstep_notifier+0x151/0x1b0 irqentry_exit_to_user_mode+0xe2/0x1b0 asm_exc_int3+0x39/0x40 RIP: 0033:0x401199 Code: 01 c2 0f b6 45 fb 88 02 83 45 fc 01 8b 45 fc 3b 45 e4 7c b7 8b 45 e4 48 98 48 8d 50 ff 48 8b 45 e8 48 01 d0 ce RSP: 002b:00007ffdf00576a8 EFLAGS: 00000206 RAX: 00007ffdf00576b0 RBX: 0000000000000000 RCX: 0000000000000ff2 RDX: 0000000000000ffc RSI: 0000000000000ffd RDI: 00007ffdf00576b0 RBP: 00007ffdf00586b0 R08: 00007feb2f9c0d20 R09: 00007feb2f9c0d20 R10: 0000000000000001 R11: 0000000000000202 R12: 0000000000401040 R13: 00007ffdf0058780 R14: 0000000000000000 R15: 0000000000000000 </TASK> This commit enforces the buffer's maxlen less than a page-size to avoid store_trace_args() out-of-memory access. Link: https://lore.kernel.org/all/20241015060148.1108331-1-mqaio@linux.alibaba.com/ Fixes: dcad1a204f72 ("tracing/uprobes: Fetch args before reserving a ring buffer") Signed-off-by: Qiao Ma <mqaio@linux.alibaba.com> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-10-20Merge tag 'sched_urgent_for_v6.12_rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduling fixes from Borislav Petkov: - Add PREEMPT_RT maintainers - Fix another aspect of delayed dequeued tasks wrt determining their state, i.e., whether they're runnable or blocked - Handle delayed dequeued tasks and their migration wrt PSI properly - Fix the situation where a delayed dequeue task gets enqueued into a new class, which should not happen - Fix a case where memory allocation would happen while the runqueue lock is held, which is a no-no - Do not over-schedule when tasks with shorter slices preempt the currently running task - Make sure delayed to deque entities are properly handled before unthrottling - Other smaller cleanups and improvements * tag 'sched_urgent_for_v6.12_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: MAINTAINERS: Add an entry for PREEMPT_RT. sched/fair: Fix external p->on_rq users sched/psi: Fix mistaken CPU pressure indication after corrupted task state bug sched/core: Dequeue PSI signals for blocked tasks that are delayed sched: Fix delayed_dequeue vs switched_from_fair() sched/core: Disable page allocation in task_tick_mm_cid() sched/deadline: Use hrtick_enabled_dl() before start_hrtick_dl() sched/eevdf: Fix wakeup-preempt by checking cfs_rq->nr_running sched: Fix sched_delayed vs cfs_bandwidth
2024-10-19Merge tag 'ftrace-v6.12-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull ftrace fixes from Steven Rostedt: "A couple of fixes to function graph infrastructure: - Fix allocation of idle shadow stack allocation during hotplug If function graph tracing is started when a CPU is offline, if it were come online during the trace then the idle task that represents the CPU will not get a shadow stack allocated for it. This means all function graph hooks that happen while that idle task is running (including in interrupt mode) will have all its events dropped. Switch over to the CPU hotplug mechanism that will have any newly brought on line CPU get a callback that can allocate the shadow stack for its idle task. - Fix allocation size of the ret_stack_list array When function graph tracing converted over to allowing more than one user at a time, it had to convert its shadow stack from an array of ret_stack structures to an array of unsigned longs. The shadow stacks are allocated in batches of 32 at a time and assigned to every running task. The batch is held by the ret_stack_list array. But when the conversion happened, instead of allocating an array of 32 pointers, it was allocated as a ret_stack itself (PAGE_SIZE). This ret_stack_list gets passed to a function that iterates over what it believes is its size defined by the FTRACE_RETSTACK_ALLOC_SIZE macro (which is 32). Luckily (PAGE_SIZE) is greater than 32 * sizeof(long), otherwise this would have been an array overflow. This still should be fixed and the ret_stack_list should be allocated to the size it is expected to be as someday it may end up being bigger than SHADOW_STACK_SIZE" * tag 'ftrace-v6.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: fgraph: Allocate ret_stack_list with proper size fgraph: Use CPU hotplug mechanism to initialize idle shadow stacks
2024-10-18fgraph: Allocate ret_stack_list with proper sizeSteven Rostedt
The ret_stack_list is an array of ret_stack shadow stacks for the function graph usage. When the first function graph is enabled, all tasks in the system get a shadow stack. The ret_stack_list is a 32 element array of pointers to these shadow stacks. It allocates the shadow stack in batches (32 stacks at a time), assigns them to running tasks, and continues until all tasks are covered. When the function graph shadow stack changed from an array of ftrace_ret_stack structures to an array of longs, the allocation of ret_stack_list went from allocating an array of 32 elements to just a block defined by SHADOW_STACK_SIZE. Luckily, that's defined as PAGE_SIZE and is much more than enough to hold 32 pointers. But it is way overkill for the amount needed to allocate. Change the allocation of ret_stack_list back to a kcalloc() of FTRACE_RETSTACK_ALLOC_SIZE pointers. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20241018215212.23f13f40@rorschach Fixes: 42675b723b484 ("function_graph: Convert ret_stack to a series of longs") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-18fgraph: Use CPU hotplug mechanism to initialize idle shadow stacksSteven Rostedt
The function graph infrastructure allocates a shadow stack for every task when enabled. This includes the idle tasks. The first time the function graph is invoked, the shadow stacks are created and never freed until the task exits. This includes the idle tasks. Only the idle tasks that were for online CPUs had their shadow stacks created when function graph tracing started. If function graph tracing is enabled and a CPU comes online, the idle task representing that CPU will not have its shadow stack created, and all function graph tracing for that idle task will be silently dropped. Instead, use the CPU hotplug mechanism to allocate the idle shadow stacks. This will include idle tasks for CPUs that come online during tracing. This issue can be reproduced by: # cd /sys/kernel/tracing # echo 0 > /sys/devices/system/cpu/cpu1/online # echo 0 > set_ftrace_pid # echo function_graph > current_tracer # echo 1 > options/funcgraph-proc # echo 1 > /sys/devices/system/cpu/cpu1 # grep '<idle>' per_cpu/cpu1/trace | head Before, nothing would show up. After: 1) <idle>-0 | 0.811 us | __enqueue_entity(); 1) <idle>-0 | 5.626 us | } /* enqueue_entity */ 1) <idle>-0 | | dl_server_update_idle_time() { 1) <idle>-0 | | dl_scaled_delta_exec() { 1) <idle>-0 | 0.450 us | arch_scale_cpu_capacity(); 1) <idle>-0 | 1.242 us | } 1) <idle>-0 | 1.908 us | } 1) <idle>-0 | | dl_server_start() { 1) <idle>-0 | | enqueue_dl_entity() { 1) <idle>-0 | | task_contending() { Note, if tracing stops and restarts, the old way would then initialize the onlined CPUs. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/20241018214300.6df82178@rorschach Fixes: 868baf07b1a25 ("ftrace: Fix memory leak with function graph and cpu hotplug") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-18Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfLinus Torvalds
Pull bpf fixes from Daniel Borkmann: - Fix BPF verifier to not affect subreg_def marks in its range propagation (Eduard Zingerman) - Fix a truncation bug in the BPF verifier's handling of coerce_reg_to_size_sx (Dimitar Kanaliev) - Fix the BPF verifier's delta propagation between linked registers under 32-bit addition (Daniel Borkmann) - Fix a NULL pointer dereference in BPF devmap due to missing rxq information (Florian Kauer) - Fix a memory leak in bpf_core_apply (Jiri Olsa) - Fix an UBSAN-reported array-index-out-of-bounds in BTF parsing for arrays of nested structs (Hou Tao) - Fix build ID fetching where memory areas backing the file were created with memfd_secret (Andrii Nakryiko) - Fix BPF task iterator tid filtering which was incorrectly using pid instead of tid (Jordan Rome) - Several fixes for BPF sockmap and BPF sockhash redirection in combination with vsocks (Michal Luczaj) - Fix riscv BPF JIT and make BPF_CMPXCHG fully ordered (Andrea Parri) - Fix riscv BPF JIT under CONFIG_CFI_CLANG to prevent the possibility of an infinite BPF tailcall (Pu Lehui) - Fix a build warning from resolve_btfids that bpf_lsm_key_free cannot be resolved (Thomas Weißschuh) - Fix a bug in kfunc BTF caching for modules where the wrong BTF object was returned (Toke Høiland-Jørgensen) - Fix a BPF selftest compilation error in cgroup-related tests with musl libc (Tony Ambardar) - Several fixes to BPF link info dumps to fill missing fields (Tyrone Wu) - Add BPF selftests for kfuncs from multiple modules, checking that the correct kfuncs are called (Simon Sundberg) - Ensure that internal and user-facing bpf_redirect flags don't overlap (Toke Høiland-Jørgensen) - Switch to use kvzmalloc to allocate BPF verifier environment (Rik van Riel) - Use raw_spinlock_t in BPF ringbuf to fix a sleep in atomic splat under RT (Wander Lairson Costa) * tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: (38 commits) lib/buildid: Handle memfd_secret() files in build_id_parse() selftests/bpf: Add test case for delta propagation bpf: Fix print_reg_state's constant scalar dump bpf: Fix incorrect delta propagation between linked registers bpf: Properly test iter/task tid filtering bpf: Fix iter/task tid filtering riscv, bpf: Make BPF_CMPXCHG fully ordered bpf, vsock: Drop static vsock_bpf_prot initialization vsock: Update msg_count on read_skb() vsock: Update rx_bytes on read_skb() bpf, sockmap: SK_DROP on attempted redirects of unsupported af_vsock selftests/bpf: Add asserts for netfilter link info bpf: Fix link info netfilter flags to populate defrag flag selftests/bpf: Add test for sign extension in coerce_subreg_to_size_sx() selftests/bpf: Add test for truncation after sign extension in coerce_reg_to_size_sx() bpf: Fix truncation bug in coerce_reg_to_size_sx() selftests/bpf: Assert link info uprobe_multi count & path_size if unset bpf: Fix unpopulated path_size when uprobe_multi fields unset selftests/bpf: Fix cross-compiling urandom_read selftests/bpf: Add test for kfunc module order ...
2024-10-17Merge branch 'linus' into sched/urgent, to resolve conflictIngo Molnar
Conflicts: kernel/sched/ext.c There's a context conflict between this upstream commit: 3fdb9ebcec10 sched_ext: Start schedulers with consistent p->scx.slice values ... and this fix in sched/urgent: 98442f0ccd82 sched: Fix delayed_dequeue vs switched_from_fair() Resolve it. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2024-10-15ring-buffer: Fix reader locking when changing the sub buffer orderPetr Pavlu
The function ring_buffer_subbuf_order_set() updates each ring_buffer_per_cpu and installs new sub buffers that match the requested page order. This operation may be invoked concurrently with readers that rely on some of the modified data, such as the head bit (RB_PAGE_HEAD), or the ring_buffer_per_cpu.pages and reader_page pointers. However, no exclusive access is acquired by ring_buffer_subbuf_order_set(). Modifying the mentioned data while a reader also operates on them can then result in incorrect memory access and various crashes. Fix the problem by taking the reader_lock when updating a specific ring_buffer_per_cpu in ring_buffer_subbuf_order_set(). Link: https://lore.kernel.org/linux-trace-kernel/20240715145141.5528-1-petr.pavlu@suse.com/ Link: https://lore.kernel.org/linux-trace-kernel/20241010195849.2f77cc3f@gandalf.local.home/ Link: https://lore.kernel.org/linux-trace-kernel/20241011112850.17212b25@gandalf.local.home/ Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20241015112440.26987-1-petr.pavlu@suse.com Fixes: 8e7b58c27b3c ("ring-buffer: Just update the subbuffers when changing their allocation order") Signed-off-by: Petr Pavlu <petr.pavlu@suse.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-14ring-buffer: Fix refcount setting of boot mapped buffersSteven Rostedt
A ring buffer which has its buffered mapped at boot up to fixed memory should not be freed. Other buffers can be. The ref counting setup was wrong for both. It made the not mapped buffers ref count have zero, and the boot mapped buffer a ref count of 1. But an normally allocated buffer should be 1, where it can be removed. Keep the ref count of a normal boot buffer with its setup ref count (do not decrement it), and increment the fixed memory boot mapped buffer's ref count. Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20241011165224.33dd2624@gandalf.local.home Fixes: e645535a954ad ("tracing: Add option to use memmapped memory for trace boot instance") Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-14sched/fair: Fix external p->on_rq usersPeter Zijlstra
Sean noted that ever since commit 152e11f6df29 ("sched/fair: Implement delayed dequeue") KVM's preemption notifiers have started mis-classifying preemption vs blocking. Notably p->on_rq is no longer sufficient to determine if a task is runnable or blocked -- the aforementioned commit introduces tasks that remain on the runqueue even through they will not run again, and should be considered blocked for many cases. Add the task_is_runnable() helper to classify things and audit all external users of the p->on_rq state. Also add a few comments. Fixes: 152e11f6df29 ("sched/fair: Implement delayed dequeue") Reported-by: Sean Christopherson <seanjc@google.com> Tested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lkml.kernel.org/r/20241010091843.GK33184@noisy.programming.kicks-ass.net
2024-10-10bpf: Fix unpopulated path_size when uprobe_multi fields unsetTyrone Wu
Previously when retrieving `bpf_link_info.uprobe_multi` with `path` and `path_size` fields unset, the `path_size` field is not populated (remains 0). This behavior was inconsistent with how other input/output string buffer fields work, as the field should be populated in cases when: - both buffer and length are set (currently works as expected) - both buffer and length are unset (not working as expected) This patch now fills the `path_size` field when `path` and `path_size` are unset. Fixes: e56fdbfb06e2 ("bpf: Add link_info support for uprobe multi link") Signed-off-by: Tyrone Wu <wudevelops@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241011000803.681190-1-wudevelops@gmail.com
2024-10-10ftrace: Make ftrace_regs abstract from direct useSteven Rostedt
ftrace_regs was created to hold registers that store information to save function parameters, return value and stack. Since it is a subset of pt_regs, it should only be used by its accessor functions. But because pt_regs can easily be taken from ftrace_regs (on most archs), it is tempting to use it directly. But when running on other architectures, it may fail to build or worse, build but crash the kernel! Instead, make struct ftrace_regs an empty structure and have the architectures define __arch_ftrace_regs and all the accessor functions will typecast to it to get to the actual fields. This will help avoid usage of ftrace_regs directly. Link: https://lore.kernel.org/all/20241007171027.629bdafd@gandalf.local.home/ Cc: "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org> Cc: "x86@kernel.org" <x86@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Naveen N Rao <naveen@kernel.org> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lore.kernel.org/20241008230628.958778821@goodmis.org Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390 Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-10fgragh: No need to invoke the function call_filter_check_discard()Steven Rostedt
The function call_filter_check_discard() has been removed in the commit 49e4154f4b16 ("tracing: Remove TRACE_EVENT_FL_FILTERED logic"), from another topic branch. But when merged together with commit 21e92806d39c6 ("function_graph: Support recording and printing the function return address") which added another call to call_filter_check_discard(), it caused the build to fail. Since the function call_filter_check_discard() is useless, it can simply be removed regardless of being merged with commit 49e4154f4b16 or not. Link: https://lore.kernel.org/all/20241010134649.43ed357c@canb.auug.org.au/ Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Donglin Peng <dolinux.peng@gmail.com> Link: https://lore.kernel.org/20241010194020.46192b21@gandalf.local.home Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Fixes: 21e92806d39c6 ("function_graph: Support recording and printing the function return address") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-10fgraph: Simplify return address printing in function graph tracerMasami Hiramatsu (Google)
Simplify return address printing in the function graph tracer by removing fgraph_extras. Since this feature is only used by the function graph tracer and the feature flags can directly accessible from the function graph tracer, fgraph_extras can be removed from the fgraph callback. Cc: Donglin Peng <dolinux.peng@gmail.com> Link: https://lore.kernel.org/172857234900.270774.15378354017601069781.stgit@devnote2 Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-09ring-buffer: Do not have boot mapped buffers hook to CPU hotplugSteven Rostedt
The boot mapped ring buffer has its buffer mapped at a fixed location found at boot up. It is not dynamic. It cannot grow or be expanded when new CPUs come online. Do not hook fixed memory mapped ring buffers to the CPU hotplug callback, otherwise it can cause a crash when it tries to add the buffer to the memory that is already fully occupied. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20241008143242.25e20801@gandalf.local.home Fixes: be68d63a139bd ("ring-buffer: Add ring_buffer_alloc_range()") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-05function_graph: Remove unnecessary initialization in ftrace_graph_ret_addr()Oleg Nesterov
After the commit 29c1c24a2707 ("function_graph: Fix up ftrace_graph_ret_addr()") ftrace_graph_ret_addr() doesn't need to initialize "int i" at the start. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Puranjay Mohan <puranjay@kernel.org> Link: https://lore.kernel.org/20240916175818.GA28944@redhat.com Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>