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2025-05-09kernel: globalize lookup_or_create_module_kobject()Shyam Saini
[ Upstream commit 7c76c813cfc42a7376378a0c4b7250db2eebab81 ] lookup_or_create_module_kobject() is marked as static and __init, to make it global drop static keyword. Since this function can be called from non-init code, use __modinit instead of __init, __modinit marker will make it __init if CONFIG_MODULES is not defined. Suggested-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Shyam Saini <shyamsaini@linux.microsoft.com> Link: https://lore.kernel.org/r/20250227184930.34163-4-shyamsaini@linux.microsoft.com Signed-off-by: Petr Pavlu <petr.pavlu@suse.com> Stable-dep-of: f95bbfe18512 ("drivers: base: handle module_kobject creation") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-09kernel: param: rename locate_module_kobjectShyam Saini
[ Upstream commit bbc9462f0cb0c8917a4908e856731708f0cee910 ] The locate_module_kobject() function looks up an existing module_kobject for a given module name. If it cannot find the corresponding module_kobject, it creates one for the given name. This commit renames locate_module_kobject() to lookup_or_create_module_kobject() to better describe its operations. This doesn't change anything functionality wise. Suggested-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Shyam Saini <shyamsaini@linux.microsoft.com> Link: https://lore.kernel.org/r/20250227184930.34163-2-shyamsaini@linux.microsoft.com Signed-off-by: Petr Pavlu <petr.pavlu@suse.com> Stable-dep-of: f95bbfe18512 ("drivers: base: handle module_kobject creation") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-09bpf: fix null dereference when computing changes_pkt_data of prog w/o subprogsEduard Zingerman
commit ac6542ad92759cda383ad62b4e4cbfc28136abc1 upstream. bpf_prog_aux->func field might be NULL if program does not have subprograms except for main sub-program. The fixed commit does bpf_prog_aux->func access unconditionally, which might lead to null pointer dereference. The bug could be triggered by replacing the following BPF program: SEC("tc") int main_changes(struct __sk_buff *sk) { bpf_skb_pull_data(sk, 0); return 0; } With the following BPF program: SEC("freplace") long changes_pkt_data(struct __sk_buff *sk) { return bpf_skb_pull_data(sk, 0); } bpf_prog_aux instance itself represents the main sub-program, use this property to fix the bug. Fixes: 81f6d0530ba0 ("bpf: check changes_pkt_data property for extension programs") Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Closes: https://lore.kernel.org/r/202412111822.qGw6tOyB-lkp@intel.com/ Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20241212070711.427443-1-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-09bpf: check changes_pkt_data property for extension programsEduard Zingerman
commit 81f6d0530ba031b5f038a091619bf2ff29568852 upstream. When processing calls to global sub-programs, verifier decides whether to invalidate all packet pointers in current state depending on the changes_pkt_data property of the global sub-program. Because of this, an extension program replacing a global sub-program must be compatible with changes_pkt_data property of the sub-program being replaced. This commit: - adds changes_pkt_data flag to struct bpf_prog_aux: - this flag is set in check_cfg() for main sub-program; - in jit_subprogs() for other sub-programs; - modifies bpf_check_attach_btf_id() to check changes_pkt_data flag; - moves call to check_attach_btf_id() after the call to check_cfg(), because it needs changes_pkt_data flag to be set: bpf_check: ... ... - check_attach_btf_id resolve_pseudo_ldimm64 resolve_pseudo_ldimm64 --> bpf_prog_is_offloaded bpf_prog_is_offloaded check_cfg check_cfg + check_attach_btf_id ... ... The following fields are set by check_attach_btf_id(): - env->ops - prog->aux->attach_btf_trace - prog->aux->attach_func_name - prog->aux->attach_func_proto - prog->aux->dst_trampoline - prog->aux->mod - prog->aux->saved_dst_attach_type - prog->aux->saved_dst_prog_type - prog->expected_attach_type Neither of these fields are used by resolve_pseudo_ldimm64() or bpf_prog_offload_verifier_prep() (for netronome and netdevsim drivers), so the reordering is safe. Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20241210041100.1898468-6-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> [ shung-hsi.yu: adapt to missing fields in "struct bpf_prog_aux". Context difference in jit_subprogs() because BPF Exception is not supported. Context difference in bpf_check() because commit 5b5f51bff1b6 "bpf: no_caller_saved_registers attribute for helper calls" is not present. ] Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-09bpf: track changes_pkt_data property for global functionsEduard Zingerman
commit 51081a3f25c742da5a659d7fc6fd77ebfdd555be upstream. When processing calls to certain helpers, verifier invalidates all packet pointers in a current state. For example, consider the following program: __attribute__((__noinline__)) long skb_pull_data(struct __sk_buff *sk, __u32 len) { return bpf_skb_pull_data(sk, len); } SEC("tc") int test_invalidate_checks(struct __sk_buff *sk) { int *p = (void *)(long)sk->data; if ((void *)(p + 1) > (void *)(long)sk->data_end) return TCX_DROP; skb_pull_data(sk, 0); *p = 42; return TCX_PASS; } After a call to bpf_skb_pull_data() the pointer 'p' can't be used safely. See function filter.c:bpf_helper_changes_pkt_data() for a list of such helpers. At the moment verifier invalidates packet pointers when processing helper function calls, and does not traverse global sub-programs when processing calls to global sub-programs. This means that calls to helpers done from global sub-programs do not invalidate pointers in the caller state. E.g. the program above is unsafe, but is not rejected by verifier. This commit fixes the omission by computing field bpf_subprog_info->changes_pkt_data for each sub-program before main verification pass. changes_pkt_data should be set if: - subprogram calls helper for which bpf_helper_changes_pkt_data returns true; - subprogram calls a global function, for which bpf_subprog_info->changes_pkt_data should be set. The verifier.c:check_cfg() pass is modified to compute this information. The commit relies on depth first instruction traversal done by check_cfg() and absence of recursive function calls: - check_cfg() would eventually visit every call to subprogram S in a state when S is fully explored; - when S is fully explored: - every direct helper call within S is explored (and thus changes_pkt_data is set if needed); - every call to subprogram S1 called by S was visited with S1 fully explored (and thus S inherits changes_pkt_data from S1). The downside of such approach is that dead code elimination is not taken into account: if a helper call inside global function is dead because of current configuration, verifier would conservatively assume that the call occurs for the purpose of the changes_pkt_data computation. Reported-by: Nick Zavaritsky <mejedi@gmail.com> Closes: https://lore.kernel.org/bpf/0498CA22-5779-4767-9C0C-A9515CEA711F@gmail.com/ Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20241210041100.1898468-4-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> [shung-hsi.yu: do not use bitfield in "struct bpf_subprog_info" because commit 406a6fa44bfb ("bpf: use bitfields for simple per-subprog bool flags") is not present and minor context difference in check_func_call() because commit 491dd8edecbc ("bpf: Emit global subprog name in verifier logs") is not present. ] Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-09bpf: refactor bpf_helper_changes_pkt_data to use helper numberEduard Zingerman
commit b238e187b4a2d3b54d80aec05a9cab6466b79dde upstream. Use BPF helper number instead of function pointer in bpf_helper_changes_pkt_data(). This would simplify usage of this function in verifier.c:check_cfg() (in a follow-up patch), where only helper number is easily available and there is no real need to lookup helper proto. Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20241210041100.1898468-3-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-09bpf: add find_containing_subprog() utility functionEduard Zingerman
commit 27e88bc4df1d80888fe1aaca786a7cc6e69587e2 upstream. Add a utility function, looking for a subprogram containing a given instruction index, rewrite find_subprog() to use this function. Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20241210041100.1898468-2-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-09tracing: Fix oob write in trace_seq_to_buffer()Jeongjun Park
commit f5178c41bb43444a6008150fe6094497135d07cb upstream. syzbot reported this bug: ================================================================== BUG: KASAN: slab-out-of-bounds in trace_seq_to_buffer kernel/trace/trace.c:1830 [inline] BUG: KASAN: slab-out-of-bounds in tracing_splice_read_pipe+0x6be/0xdd0 kernel/trace/trace.c:6822 Write of size 4507 at addr ffff888032b6b000 by task syz.2.320/7260 CPU: 1 UID: 0 PID: 7260 Comm: syz.2.320 Not tainted 6.15.0-rc1-syzkaller-00301-g3bde70a2c827 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xc3/0x670 mm/kasan/report.c:521 kasan_report+0xe0/0x110 mm/kasan/report.c:634 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189 __asan_memcpy+0x3c/0x60 mm/kasan/shadow.c:106 trace_seq_to_buffer kernel/trace/trace.c:1830 [inline] tracing_splice_read_pipe+0x6be/0xdd0 kernel/trace/trace.c:6822 .... ================================================================== It has been reported that trace_seq_to_buffer() tries to copy more data than PAGE_SIZE to buf. Therefore, to prevent this, we should use the smaller of trace_seq_used(&iter->seq) and PAGE_SIZE as an argument. Link: https://lore.kernel.org/20250422113026.13308-1-aha310510@gmail.com Reported-by: syzbot+c8cd2d2c412b868263fb@syzkaller.appspotmail.com Fixes: 3c56819b14b0 ("tracing: splice support for tracing_pipe") Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Jeongjun Park <aha310510@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-09tracing: Do not take trace_event_sem in print_event_fields()Steven Rostedt
commit 0a8f11f8569e7ed16cbcedeb28c4350f6378fea6 upstream. On some paths in print_event_fields() it takes the trace_event_sem for read, even though it should always be held when the function is called. Remove the taking of that mutex and add a lockdep_assert_held_read() to make sure the trace_event_sem is held when print_event_fields() is called. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20250501224128.0b1f0571@batman.local.home Fixes: 80a76994b2d88 ("tracing: Add "fields" option to show raw trace event fields") Reported-by: syzbot+441582c1592938fccf09@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/6813ff5e.050a0220.14dd7d.001b.GAE@google.com/ Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-02timekeeping: Add a lockdep override in tick_freeze()Sebastian Andrzej Siewior
[ Upstream commit 92e250c624ea37fde64bfd624fd2556f0d846f18 ] tick_freeze() acquires a raw spinlock (tick_freeze_lock). Later in the callchain (timekeeping_suspend() -> mc146818_avoid_UIP()) the RTC driver acquires a spinlock which becomes a sleeping lock on PREEMPT_RT. Lockdep complains about this lock nesting. Add a lockdep override for this special case and a comment explaining why it is okay. Reported-by: Borislav Petkov <bp@alien8.de> Reported-by: Chris Bainbridge <chris.bainbridge@gmail.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/all/20250404133429.pnAzf-eF@linutronix.de Closes: https://lore.kernel.org/all/20250330113202.GAZ-krsjAnurOlTcp-@fat_crate.local/ Closes: https://lore.kernel.org/all/CAP-bSRZ0CWyZZsMtx046YV8L28LhY0fson2g4EqcwRAVN1Jk+Q@mail.gmail.com/ Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-02perf/core: Fix WARN_ON(!ctx) in __free_event() for partial initGabriel Shahrouzi
[ Upstream commit 0ba3a4ab76fd3367b9cb680cad70182c896c795c ] Move the get_ctx(child_ctx) call and the child_event->ctx assignment to occur immediately after the child event is allocated. Ensure that child_event->ctx is non-NULL before any subsequent error path within inherit_event calls free_event(), satisfying the assumptions of the cleanup code. Details: There's no clear Fixes tag, because this bug is a side-effect of multiple interacting commits over time (up to 15 years old), not a single regression. The code initially incremented refcount then assigned context immediately after the child_event was created. Later, an early validity check for child_event was added before the refcount/assignment. Even later, a WARN_ON_ONCE() cleanup check was added, assuming event->ctx is valid if the pmu_ctx is valid. The problem is that the WARN_ON_ONCE() could trigger after the initial check passed but before child_event->ctx was assigned, violating its precondition. The solution is to assign child_event->ctx right after its initial validation. This ensures the context exists for any subsequent checks or cleanup routines, resolving the WARN_ON_ONCE(). To resolve it, defer the refcount update and child_event->ctx assignment directly after child_event->pmu_ctx is set but before checking if the parent event is orphaned. The cleanup routine depends on event->pmu_ctx being non-NULL before it verifies event->ctx is non-NULL. This also maintains the author's original intent of passing in child_ctx to find_get_pmu_context before its refcount/assignment. [ mingo: Expanded the changelog from another email by Gabriel Shahrouzi. ] Reported-by: syzbot+ff3aa851d46ab82953a3@syzkaller.appspotmail.com Signed-off-by: Gabriel Shahrouzi <gshahrouzi@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Bangoria <ravi.bangoria@amd.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Link: https://lore.kernel.org/r/20250405203036.582721-1-gshahrouzi@gmail.com Closes: https://syzkaller.appspot.com/bug?extid=ff3aa851d46ab82953a3 Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-02objtool, panic: Disable SMAP in __stack_chk_fail()Josh Poimboeuf
[ Upstream commit 72c774aa9d1e16bfd247096935e7dae194d84929 ] __stack_chk_fail() can be called from uaccess-enabled code. Make sure uaccess gets disabled before calling panic(). Fixes the following warning: kernel/trace/trace_branch.o: error: objtool: ftrace_likely_update+0x1ea: call to __stack_chk_fail() with UACCESS enabled Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/a3e97e0119e1b04c725a8aa05f7bc83d98e657eb.1742852847.git.jpoimboe@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-02bpf: Reject attaching fexit/fmod_ret to __noreturn functionsYafang Shao
[ Upstream commit cfe816d469dce9c0864062cf65dd7b3c42adc6f8 ] If we attach fexit/fmod_ret to __noreturn functions, it will cause an issue that the bpf trampoline image will be left over even if the bpf link has been destroyed. Take attaching do_exit() with fexit for example. The fexit works as follows, bpf_trampoline + __bpf_tramp_enter + percpu_ref_get(&tr->pcref); + call do_exit() + __bpf_tramp_exit + percpu_ref_put(&tr->pcref); Since do_exit() never returns, the refcnt of the trampoline image is never decremented, preventing it from being freed. That can be verified with as follows, $ bpftool link show <<<< nothing output $ grep "bpf_trampoline_[0-9]" /proc/kallsyms ffffffffc04cb000 t bpf_trampoline_6442526459 [bpf] <<<< leftover In this patch, all functions annotated with __noreturn are rejected, except for the following cases: - Functions that result in a system reboot, such as panic, machine_real_restart and rust_begin_unwind - Functions that are never executed by tasks, such as rest_init and cpu_startup_entry - Functions implemented in assembly, such as rewind_stack_and_make_dead and xen_cpu_bringup_again, lack an associated BTF ID. With this change, attaching fexit probes to functions like do_exit() will be rejected. $ ./fexit libbpf: prog 'fexit': BPF program load failed: -EINVAL libbpf: prog 'fexit': -- BEGIN PROG LOAD LOG -- Attaching fexit/fmod_ret to __noreturn functions is rejected. Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Link: https://lore.kernel.org/r/20250318114447.75484-2-laoar.shao@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-02bpf: Only fails the busy counter check in bpf_cgrp_storage_get if it creates ↵Martin KaFai Lau
storage [ Upstream commit f4edc66e48a694b3e6d164cc71f059de542dfaec ] The current cgrp storage has a percpu counter, bpf_cgrp_storage_busy, to detect potential deadlock at a spin_lock that the local storage acquires during new storage creation. There are false positives. It turns out to be too noisy in production. For example, a bpf prog may be doing a bpf_cgrp_storage_get on map_a. An IRQ comes in and triggers another bpf_cgrp_storage_get on a different map_b. It will then trigger the false positive deadlock check in the percpu counter. On top of that, both are doing lookup only and no need to create new storage, so practically it does not need to acquire the spin_lock. The bpf_task_storage_get already has a strategy to minimize this false positive by only failing if the bpf_task_storage_get needs to create a new storage and the percpu counter is busy. Creating a new storage is the only time it must acquire the spin_lock. This patch borrows the same idea. Unlike task storage that has a separate variant for tracing (_recur) and non-tracing, this patch stays with one bpf_cgrp_storage_get helper to keep it simple for now in light of the upcoming res_spin_lock. The variable could potentially use a better name noTbusy instead of nobusy. This patch follows the same naming in bpf_task_storage_get for now. I have tested it by temporarily adding noinline to the cgroup_storage_lookup(), traced it by fentry, and the fentry program succeeded in calling bpf_cgrp_storage_get(). Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20250318182759.3676094-1-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-02bpf: Fix deadlock between rcu_tasks_trace and event_mutex.Alexei Starovoitov
[ Upstream commit 4580f4e0ebdf8dc8d506ae926b88510395a0c1d1 ] Fix the following deadlock: CPU A _free_event() perf_kprobe_destroy() mutex_lock(&event_mutex) perf_trace_event_unreg() synchronize_rcu_tasks_trace() There are several paths where _free_event() grabs event_mutex and calls sync_rcu_tasks_trace. Above is one such case. CPU B bpf_prog_test_run_syscall() rcu_read_lock_trace() bpf_prog_run_pin_on_cpu() bpf_prog_load() bpf_tracing_func_proto() trace_set_clr_event() mutex_lock(&event_mutex) Delegate trace_set_clr_event() to workqueue to avoid such lock dependency. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20250224221637.4780-1-alexei.starovoitov@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-02dma/contiguous: avoid warning about unused size_bytesArnd Bergmann
[ Upstream commit d7b98ae5221007d3f202746903d4c21c7caf7ea9 ] When building with W=1, this variable is unused for configs with CONFIG_CMA_SIZE_SEL_PERCENTAGE=y: kernel/dma/contiguous.c:67:26: error: 'size_bytes' defined but not used [-Werror=unused-const-variable=] Change this to a macro to avoid the warning. Fixes: c64be2bb1c6e ("drivers: add Contiguous Memory Allocator") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Link: https://lore.kernel.org/r/20250409151557.3890443-1-arnd@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-02cpufreq/sched: Explicitly synchronize limits_changed flag handlingRafael J. Wysocki
[ Upstream commit 79443a7e9da3c9f68290a8653837e23aba0fa89f ] The handling of the limits_changed flag in struct sugov_policy needs to be explicitly synchronized to ensure that cpufreq policy limits updates will not be missed in some cases. Without that synchronization it is theoretically possible that the limits_changed update in sugov_should_update_freq() will be reordered with respect to the reads of the policy limits in cpufreq_driver_resolve_freq() and in that case, if the limits_changed update in sugov_limits() clobbers the one in sugov_should_update_freq(), the new policy limits may not take effect for a long time. Likewise, the limits_changed update in sugov_limits() may theoretically get reordered with respect to the updates of the policy limits in cpufreq_set_policy() and if sugov_should_update_freq() runs between them, the policy limits change may be missed. To ensure that the above situations will not take place, add memory barriers preventing the reordering in question from taking place and add READ_ONCE() and WRITE_ONCE() annotations around all of the limits_changed flag updates to prevent the compiler from messing up with that code. Fixes: 600f5badb78c ("cpufreq: schedutil: Don't skip freq update when limits change") Cc: 5.3+ <stable@vger.kernel.org> # 5.3+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Christian Loehle <christian.loehle@arm.com> Link: https://patch.msgid.link/3376719.44csPzL39Z@rjwysocki.net Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-02sched/cpufreq: Rework schedutil governor performance estimationVincent Guittot
[ Upstream commit 9c0b4bb7f6303c9c4e2e34984c46f5a86478f84d ] The current method to take into account uclamp hints when estimating the target frequency can end in a situation where the selected target frequency is finally higher than uclamp hints, whereas there are no real needs. Such cases mainly happen because we are currently mixing the traditional scheduler utilization signal with the uclamp performance hints. By adding these 2 metrics, we loose an important information when it comes to select the target frequency, and we have to make some assumptions which can't fit all cases. Rework the interface between the scheduler and schedutil governor in order to propagate all information down to the cpufreq governor. effective_cpu_util() interface changes and now returns the actual utilization of the CPU with 2 optional inputs: - The minimum performance for this CPU; typically the capacity to handle the deadline task and the interrupt pressure. But also uclamp_min request when available. - The maximum targeting performance for this CPU which reflects the maximum level that we would like to not exceed. By default it will be the CPU capacity but can be reduced because of some performance hints set with uclamp. The value can be lower than actual utilization and/or min performance level. A new sugov_effective_cpu_perf() interface is also available to compute the final performance level that is targeted for the CPU, after applying some cpufreq headroom and taking into account all inputs. With these 2 functions, schedutil is now able to decide when it must go above uclamp hints. It now also has a generic way to get the min performance level. The dependency between energy model and cpufreq governor and its headroom policy doesn't exist anymore. eenv_pd_max_util() asks schedutil for the targeted performance after applying the impact of the waking task. [ mingo: Refined the changelog & C comments. ] Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Rafael J. Wysocki <rafael@kernel.org> Link: https://lore.kernel.org/r/20231122133904.446032-2-vincent.guittot@linaro.org Stable-dep-of: 79443a7e9da3 ("cpufreq/sched: Explicitly synchronize limits_changed flag handling") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-02sched/topology: Consolidate and clean up access to a CPU's max compute capacityVincent Guittot
[ Upstream commit 7bc263840bc3377186cb06b003ac287bb2f18ce2 ] Remove the rq::cpu_capacity_orig field and use arch_scale_cpu_capacity() instead. The scheduler uses 3 methods to get access to a CPU's max compute capacity: - arch_scale_cpu_capacity(cpu) which is the default way to get a CPU's capacity. - cpu_capacity_orig field which is periodically updated with arch_scale_cpu_capacity(). - capacity_orig_of(cpu) which encapsulates rq->cpu_capacity_orig. There is no real need to save the value returned by arch_scale_cpu_capacity() in struct rq. arch_scale_cpu_capacity() returns: - either a per_cpu variable. - or a const value for systems which have only one capacity. Remove rq::cpu_capacity_orig and use arch_scale_cpu_capacity() everywhere. No functional changes. Some performance tests on Arm64: - small SMP device (hikey): no noticeable changes - HMP device (RB5): hackbench shows minor improvement (1-2%) - large smp (thx2): hackbench and tbench shows minor improvement (1%) Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Link: https://lore.kernel.org/r/20231009103621.374412-2-vincent.guittot@linaro.org Stable-dep-of: 79443a7e9da3 ("cpufreq/sched: Explicitly synchronize limits_changed flag handling") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-02tracing: Verify event formats that have "%*p.."Steven Rostedt
[ Upstream commit ea8d7647f9ddf1f81e2027ed305299797299aa03 ] The trace event verifier checks the formats of trace events to make sure that they do not point at memory that is not in the trace event itself or in data that will never be freed. If an event references data that was allocated when the event triggered and that same data is freed before the event is read, then the kernel can crash by reading freed memory. The verifier runs at boot up (or module load) and scans the print formats of the events and checks their arguments to make sure that dereferenced pointers are safe. If the format uses "%*p.." the verifier will ignore it, and that could be dangerous. Cover this case as well. Also add to the sample code a use case of "%*pbl". Link: https://lore.kernel.org/all/bcba4d76-2c3f-4d11-baf0-02905db953dd@oracle.com/ Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Fixes: 5013f454a352c ("tracing: Add check of trace event print fmts for dereferencing pointers") Link: https://lore.kernel.org/20250327195311.2d89ec66@gandalf.local.home Reported-by: Libo Chen <libo.chen@oracle.com> Reviewed-by: Libo Chen <libo.chen@oracle.com> Tested-by: Libo Chen <libo.chen@oracle.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-02module: sign with sha512 instead of sha1 by defaultThorsten Leemhuis
commit f3b93547b91ad849b58eb5ab2dd070950ad7beb3 upstream. Switch away from using sha1 for module signing by default and use the more modern sha512 instead, which is what among others Arch, Fedora, RHEL, and Ubuntu are currently using for their kernels. Sha1 has not been considered secure against well-funded opponents since 2005[1]; since 2011 the NIST and other organizations furthermore recommended its replacement[2]. This is why OpenSSL on RHEL9, Fedora Linux 41+[3], and likely some other current and future distributions reject the creation of sha1 signatures, which leads to a build error of allmodconfig configurations: 80A20474797F0000:error:03000098:digital envelope routines:do_sigver_init:invalid digest:crypto/evp/m_sigver.c:342: make[4]: *** [.../certs/Makefile:53: certs/signing_key.pem] Error 1 make[4]: *** Deleting file 'certs/signing_key.pem' make[4]: *** Waiting for unfinished jobs.... make[3]: *** [.../scripts/Makefile.build:478: certs] Error 2 make[2]: *** [.../Makefile:1936: .] Error 2 make[1]: *** [.../Makefile:224: __sub-make] Error 2 make[1]: Leaving directory '...' make: *** [Makefile:224: __sub-make] Error 2 This change makes allmodconfig work again and sets a default that is more appropriate for current and future users, too. Link: https://www.schneier.com/blog/archives/2005/02/cryptanalysis_o.html [1] Link: https://csrc.nist.gov/projects/hash-functions [2] Link: https://fedoraproject.org/wiki/Changes/OpenSSLDistrustsha1SigVer [3] Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Tested-by: kdevops <kdevops@lists.linux.dev> [0] Link: https://github.com/linux-kdevops/linux-modules-kpd/actions/runs/11420092929/job/31775404330 [0] Link: https://lore.kernel.org/r/52ee32c0c92afc4d3263cea1f8a1cdc809728aff.1729088288.git.linux@leemhuis.info Signed-off-by: Petr Pavlu <petr.pavlu@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-25tracing: Fix filter string testingSteven Rostedt
commit a8c5b0ed89a3f2c81c6ae0b041394e6eea0e7024 upstream. The filter string testing uses strncpy_from_kernel/user_nofault() to retrieve the string to test the filter against. The if() statement was incorrect as it considered 0 as a fault, when it is only negative that it faulted. Running the following commands: # cd /sys/kernel/tracing # echo "filename.ustring ~ \"/proc*\"" > events/syscalls/sys_enter_openat/filter # echo 1 > events/syscalls/sys_enter_openat/enable # ls /proc/$$/maps # cat trace Would produce nothing, but with the fix it will produce something like: ls-1192 [007] ..... 8169.828333: sys_openat(dfd: ffffffffffffff9c, filename: 7efc18359904, flags: 80000, mode: 0) Link: https://lore.kernel.org/all/CAEf4BzbVPQ=BjWztmEwBPRKHUwNfKBkS3kce-Rzka6zvbQeVpg@mail.gmail.com/ Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Link: https://lore.kernel.org/20250417183003.505835fb@gandalf.local.home Fixes: 77360f9bbc7e5 ("tracing: Add test for user space strings when filtering on string pointers") Reported-by: Andrii Nakryiko <andrii.nakryiko@gmail.com> Reported-by: Mykyta Yatsenko <mykyta.yatsenko5@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-25ftrace: fix incorrect hash size in register_ftrace_direct()Menglong Dong
[ Upstream commit 92f1d3b40179b15630d72e2c6e4e25a899b67ba9 ] The maximum of the ftrace hash bits is made fls(32) in register_ftrace_direct(), which seems illogical. So, we fix it by making the max hash bits FTRACE_HASH_MAX_BITS instead. Link: https://lore.kernel.org/20250413014444.36724-1-dongml2@chinatelecom.cn Fixes: d05cb470663a ("ftrace: Fix modification of direct_function hash while in use") Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-25cpufreq/sched: Fix the usage of CPUFREQ_NEED_UPDATE_LIMITSRafael J. Wysocki
[ Upstream commit cfde542df7dd51d26cf667f4af497878ddffd85a ] Commit 8e461a1cb43d ("cpufreq: schedutil: Fix superfluous updates caused by need_freq_update") modified sugov_should_update_freq() to set the need_freq_update flag only for drivers with CPUFREQ_NEED_UPDATE_LIMITS set, but that flag generally needs to be set when the policy limits change because the driver callback may need to be invoked for the new limits to take effect. However, if the return value of cpufreq_driver_resolve_freq() after applying the new limits is still equal to the previously selected frequency, the driver callback needs to be invoked only in the case when CPUFREQ_NEED_UPDATE_LIMITS is set (which means that the driver specifically wants its callback to be invoked every time the policy limits change). Update the code accordingly to avoid missing policy limits changes for drivers without CPUFREQ_NEED_UPDATE_LIMITS. Fixes: 8e461a1cb43d ("cpufreq: schedutil: Fix superfluous updates caused by need_freq_update") Closes: https://lore.kernel.org/lkml/Z_Tlc6Qs-tYpxWYb@linaro.org/ Reported-by: Stephan Gerhold <stephan.gerhold@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Christian Loehle <christian.loehle@arm.com> Link: https://patch.msgid.link/3010358.e9J7NaK4W3@rjwysocki.net Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-25ftrace: Add cond_resched() to ftrace_graph_set_hash()zhoumin
commit 42ea22e754ba4f2b86f8760ca27f6f71da2d982c upstream. When the kernel contains a large number of functions that can be traced, the loop in ftrace_graph_set_hash() may take a lot of time to execute. This may trigger the softlockup watchdog. Add cond_resched() within the loop to allow the kernel to remain responsive even when processing a large number of functions. This matches the cond_resched() that is used in other locations of the code that iterates over all functions that can be traced. Cc: stable@vger.kernel.org Fixes: b9b0c831bed26 ("ftrace: Convert graph filter to use hash tables") Link: https://lore.kernel.org/tencent_3E06CE338692017B5809534B9C5C03DA7705@qq.com Signed-off-by: zhoumin <teczm@foxmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-25tracing: Do not add length to print format in synthetic eventsSteven Rostedt
commit e1a453a57bc76be678bd746f84e3d73f378a9511 upstream. The following causes a vsnprintf fault: # echo 's:wake_lat char[] wakee; u64 delta;' >> /sys/kernel/tracing/dynamic_events # echo 'hist:keys=pid:ts=common_timestamp.usecs if !(common_flags & 0x18)' > /sys/kernel/tracing/events/sched/sched_waking/trigger # echo 'hist:keys=next_pid:delta=common_timestamp.usecs-$ts:onmatch(sched.sched_waking).trace(wake_lat,next_comm,$delta)' > /sys/kernel/tracing/events/sched/sched_switch/trigger Because the synthetic event's "wakee" field is created as a dynamic string (even though the string copied is not). The print format to print the dynamic string changed from "%*s" to "%s" because another location (__set_synth_event_print_fmt()) exported this to user space, and user space did not need that. But it is still used in print_synth_event(), and the output looks like: <idle>-0 [001] d..5. 193.428167: wake_lat: wakee=(efault)sshd-sessiondelta=155 sshd-session-879 [001] d..5. 193.811080: wake_lat: wakee=(efault)kworker/u34:5delta=58 <idle>-0 [002] d..5. 193.811198: wake_lat: wakee=(efault)bashdelta=91 bash-880 [002] d..5. 193.811371: wake_lat: wakee=(efault)kworker/u35:2delta=21 <idle>-0 [001] d..5. 193.811516: wake_lat: wakee=(efault)sshd-sessiondelta=129 sshd-session-879 [001] d..5. 193.967576: wake_lat: wakee=(efault)kworker/u34:5delta=50 The length isn't needed as the string is always nul terminated. Just print the string and not add the length (which was hard coded to the max string length anyway). Cc: stable@vger.kernel.org Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Tom Zanussi <zanussi@kernel.org> Cc: Douglas Raillard <douglas.raillard@arm.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Link: https://lore.kernel.org/20250407154139.69955768@gandalf.local.home Fixes: 4d38328eb442d ("tracing: Fix synth event printk format for str fields"); Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-25locking/lockdep: Decrease nr_unused_locks if lock unused in zap_class()Boqun Feng
commit 495f53d5cca0f939eaed9dca90b67e7e6fb0e30c upstream. Currently, when a lock class is allocated, nr_unused_locks will be increased by 1, until it gets used: nr_unused_locks will be decreased by 1 in mark_lock(). However, one scenario is missed: a lock class may be zapped without even being used once. This could result into a situation that nr_unused_locks != 0 but no unused lock class is active in the system, and when `cat /proc/lockdep_stats`, a WARN_ON() will be triggered in a CONFIG_DEBUG_LOCKDEP=y kernel: [...] DEBUG_LOCKS_WARN_ON(debug_atomic_read(nr_unused_locks) != nr_unused) [...] WARNING: CPU: 41 PID: 1121 at kernel/locking/lockdep_proc.c:283 lockdep_stats_show+0xba9/0xbd0 And as a result, lockdep will be disabled after this. Therefore, nr_unused_locks needs to be accounted correctly at zap_class() time. Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Waiman Long <longman@redhat.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20250326180831.510348-1-boqun.feng@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-25tracing: probe-events: Add comments about entry data storing codeMasami Hiramatsu (Google)
[ Upstream commit bb9c6020f4c3a07a90dc36826cb5fbe83f09efd5 ] Add comments about entry data storing code to __store_entry_arg() and traceprobe_get_entry_data_size(). These are a bit complicated because of building the entry data storing code and scanning it. This just add comments, no behavior change. Link: https://lore.kernel.org/all/174061715004.501424.333819546601401102.stgit@devnote2/ Reported-by: Steven Rostedt <rostedt@goodmis.org> Closes: https://lore.kernel.org/all/20250226102223.586d7119@gandalf.local.home/ Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-25tracing: fix return value in __ftrace_event_enable_disable for ↵Gabriele Paoloni
TRACE_REG_UNREGISTER [ Upstream commit 0c588ac0ca6c22b774d9ad4a6594681fdfa57d9d ] When __ftrace_event_enable_disable invokes the class callback to unregister the event, the return value is not reported up to the caller, hence leading to event unregister failures being silently ignored. This patch assigns the ret variable to the invocation of the event unregister callback, so that its return value is stored and reported to the caller, and it raises a warning in case of error. Link: https://lore.kernel.org/20250321170821.101403-1-gpaoloni@redhat.com Signed-off-by: Gabriele Paoloni <gpaoloni@redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10tracing: Do not use PERF enums when perf is not definedSteven Rostedt
commit 8eb1518642738c6892bd629b46043513a3bf1a6a upstream. An update was made to up the module ref count when a synthetic event is registered for both trace and perf events. But if perf is not configured in, the perf enums used will cause the kernel to fail to build. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Douglas Raillard <douglas.raillard@arm.com> Link: https://lore.kernel.org/20250323152151.528b5ced@batman.local.home Fixes: 21581dd4e7ff ("tracing: Ensure module defining synth event cannot be unloaded while tracing") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202503232230.TeREVy8R-lkp@intel.com/ Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-10tracing/osnoise: Fix possible recursive locking for cpus_read_lock()Ran Xiaokai
commit 7e6b3fcc9c5294aeafed0dbe1a09a1bc899bd0f2 upstream. Lockdep reports this deadlock log: osnoise: could not start sampling thread ============================================ WARNING: possible recursive locking detected -------------------------------------------- CPU0 ---- lock(cpu_hotplug_lock); lock(cpu_hotplug_lock); Call Trace: <TASK> print_deadlock_bug+0x282/0x3c0 __lock_acquire+0x1610/0x29a0 lock_acquire+0xcb/0x2d0 cpus_read_lock+0x49/0x120 stop_per_cpu_kthreads+0x7/0x60 start_kthread+0x103/0x120 osnoise_hotplug_workfn+0x5e/0x90 process_one_work+0x44f/0xb30 worker_thread+0x33e/0x5e0 kthread+0x206/0x3b0 ret_from_fork+0x31/0x50 ret_from_fork_asm+0x11/0x20 </TASK> This is the deadlock scenario: osnoise_hotplug_workfn() guard(cpus_read_lock)(); // first lock call start_kthread(cpu) if (IS_ERR(kthread)) { stop_per_cpu_kthreads(); { cpus_read_lock(); // second lock call. Cause the AA deadlock } } It is not necessary to call stop_per_cpu_kthreads() which stops osnoise kthread for every other CPUs in the system if a failure occurs during hotplug of a certain CPU. For start_per_cpu_kthreads(), if the start_kthread() call fails, this function calls stop_per_cpu_kthreads() to handle the error. Therefore, similarly, there is no need to call stop_per_cpu_kthreads() again within start_kthread(). So just remove stop_per_cpu_kthreads() from start_kthread to solve this issue. Cc: stable@vger.kernel.org Link: https://lore.kernel.org/20250321095249.2739397-1-ranxiaokai627@163.com Fixes: c8895e271f79 ("trace/osnoise: Support hotplug operations") Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-10tracing: Fix synth event printk format for str fieldsDouglas Raillard
commit 4d38328eb442dc06aec4350fd9594ffa6488af02 upstream. The printk format for synth event uses "%.*s" to print string fields, but then only passes the pointer part as var arg. Replace %.*s with %s as the C string is guaranteed to be null-terminated. The output in print fmt should never have been updated as __get_str() handles the string limit because it can access the length of the string in the string meta data that is saved in the ring buffer. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Fixes: 8db4d6bfbbf92 ("tracing: Change synthetic event string format to limit printed length") Link: https://lore.kernel.org/20250325165202.541088-1-douglas.raillard@arm.com Signed-off-by: Douglas Raillard <douglas.raillard@arm.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-10tracing: Ensure module defining synth event cannot be unloaded while tracingDouglas Raillard
commit 21581dd4e7ff6c07d0ab577e3c32b13a74b31522 upstream. Currently, using synth_event_delete() will fail if the event is being used (tracing in progress), but that is normally done in the module exit function. At that stage, failing is problematic as returning a non-zero status means the module will become locked (impossible to unload or reload again). Instead, ensure the module exit function does not get called in the first place by increasing the module refcnt when the event is enabled. Cc: stable@vger.kernel.org Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Fixes: 35ca5207c2d11 ("tracing: Add synthetic event command generation functions") Link: https://lore.kernel.org/20250318180906.226841-1-douglas.raillard@arm.com Signed-off-by: Douglas Raillard <douglas.raillard@arm.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-10tracing: Fix use-after-free in print_graph_function_flags during tracer ↵Tengda Wu
switching commit 7f81f27b1093e4895e87b74143c59c055c3b1906 upstream. Kairui reported a UAF issue in print_graph_function_flags() during ftrace stress testing [1]. This issue can be reproduced if puting a 'mdelay(10)' after 'mutex_unlock(&trace_types_lock)' in s_start(), and executing the following script: $ echo function_graph > current_tracer $ cat trace > /dev/null & $ sleep 5 # Ensure the 'cat' reaches the 'mdelay(10)' point $ echo timerlat > current_tracer The root cause lies in the two calls to print_graph_function_flags within print_trace_line during each s_show(): * One through 'iter->trace->print_line()'; * Another through 'event->funcs->trace()', which is hidden in print_trace_fmt() before print_trace_line returns. Tracer switching only updates the former, while the latter continues to use the print_line function of the old tracer, which in the script above is print_graph_function_flags. Moreover, when switching from the 'function_graph' tracer to the 'timerlat' tracer, s_start only calls graph_trace_close of the 'function_graph' tracer to free 'iter->private', but does not set it to NULL. This provides an opportunity for 'event->funcs->trace()' to use an invalid 'iter->private'. To fix this issue, set 'iter->private' to NULL immediately after freeing it in graph_trace_close(), ensuring that an invalid pointer is not passed to other tracers. Additionally, clean up the unnecessary 'iter->private = NULL' during each 'cat trace' when using wakeup and irqsoff tracers. [1] https://lore.kernel.org/all/20231112150030.84609-1-ryncsn@gmail.com/ Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Zheng Yejian <zhengyejian1@huawei.com> Link: https://lore.kernel.org/20250320122137.23635-1-wutengda@huaweicloud.com Fixes: eecb91b9f98d ("tracing: Fix memleak due to race between current_tracer and trace") Closes: https://lore.kernel.org/all/CAMgjq7BW79KDSCyp+tZHjShSzHsScSiJxn5ffskp-QzVM06fxw@mail.gmail.com/ Reported-by: Kairui Song <kasong@tencent.com> Signed-off-by: Tengda Wu <wutengda@huaweicloud.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-10tracing: Correct the refcount if the hist/hist_debug file fails to openTengda Wu
[ Upstream commit 0b4ffbe4888a2c71185eaf5c1a02dd3586a9bc04 ] The function event_{hist,hist_debug}_open() maintains the refcount of 'file->tr' and 'file' through tracing_open_file_tr(). However, it does not roll back these counts on subsequent failure paths, resulting in a refcount leak. A very obvious case is that if the hist/hist_debug file belongs to a specific instance, the refcount leak will prevent the deletion of that instance, as it relies on the condition 'tr->ref == 1' within __remove_instance(). Fix this by calling tracing_release_file_tr() on all failure paths in event_{hist,hist_debug}_open() to correct the refcount. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Zheng Yejian <zhengyejian1@huawei.com> Link: https://lore.kernel.org/20250314065335.1202817-1-wutengda@huaweicloud.com Fixes: 1cc111b9cddc ("tracing: Fix uaf issue when open the hist or hist_debug file") Signed-off-by: Tengda Wu <wutengda@huaweicloud.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10tracing/hist: Support POLLPRI event for poll on histogramMasami Hiramatsu (Google)
[ Upstream commit 66fc6f521a0b91051ce6968a216a30bc52267bf8 ] Since POLLIN will not be flushed until the hist file is read, the user needs to repeatedly read() and poll() on the hist file for monitoring the event continuously. But the read() is somewhat redundant when the user is only monitoring for event updates. Add POLLPRI poll event on the hist file so the event returns when a histogram is updated after open(), poll() or read(). Thus it is possible to wait for the next event without having to issue a read(). Cc: Shuah Khan <shuah@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/173527248770.464571.2536902137325258133.stgit@devnote2 Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Stable-dep-of: 0b4ffbe4888a ("tracing: Correct the refcount if the hist/hist_debug file fails to open") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10tracing/hist: Add poll(POLLIN) support on hist fileMasami Hiramatsu (Google)
[ Upstream commit 1bd13edbbed6e7e396f1aab92b224a4775218e68 ] Add poll syscall support on the `hist` file. The Waiter will be waken up when the histogram is updated with POLLIN. Currently, there is no way to wait for a specific event in userspace. So user needs to peek the `trace` periodicaly, or wait on `trace_pipe`. But it is not a good idea to peek at the `trace` for an event that randomly happens. And `trace_pipe` is not coming back until a page is filled with events. This allows a user to wait for a specific event on the `hist` file. User can set a histogram trigger on the event which they want to monitor and poll() on its `hist` file. Since this poll() returns POLLIN, the next poll() will return soon unless a read() happens on that hist file. NOTE: To read the hist file again, you must set the file offset to 0, but just for monitoring the event, you may not need to read the histogram. Cc: Shuah Khan <shuah@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/173527247756.464571.14236296701625509931.stgit@devnote2 Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Stable-dep-of: 0b4ffbe4888a ("tracing: Correct the refcount if the hist/hist_debug file fails to open") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10tracing: Switch trace_events_hist.c code over to use guard()Steven Rostedt
[ Upstream commit 2b36a97aeeb71b1e4a48bfedc7f21f44aeb1e6fb ] There are a couple functions in trace_events_hist.c that have "goto out" or equivalent on error in order to release locks that were taken. This can be error prone or just simply make the code more complex. Switch every location that ends with unlocking a mutex on error over to using the guard(mutex)() infrastructure to let the compiler worry about releasing locks. This makes the code easier to read and understand. 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: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/20241219201345.694601480@goodmis.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Stable-dep-of: 0b4ffbe4888a ("tracing: Correct the refcount if the hist/hist_debug file fails to open") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10tracing: Allow creating instances with specified system eventsSteven Rostedt (Google)
[ Upstream commit d23569979ca1cd139a42c410e0c7b9e6014c3b3a ] A trace instance may only need to enable specific events. As the eventfs directory of an instance currently creates all events which adds overhead, allow internal instances to be created with just the events in systems that they care about. This currently only deals with systems and not individual events, but this should bring down the overhead of creating instances for specific use cases quite bit. The trace_array_get_by_name() now has another parameter "systems". This parameter is a const string pointer of a comma/space separated list of event systems that should be created by the trace_array. (Note if the trace_array already exists, this parameter is ignored). The list of systems is saved and if a module is loaded, its events will not be added unless the system for those events also match the systems string. Link: https://lore.kernel.org/linux-trace-kernel/20231213093701.03fddec0@gandalf.local.home Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Sean Paul <seanpaul@chromium.org> Cc: Arun Easi <aeasi@marvell.com> Cc: Daniel Wagner <dwagner@suse.de> Tested-by: Dmytro Maluka <dmaluka@chromium.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Stable-dep-of: 0b4ffbe4888a ("tracing: Correct the refcount if the hist/hist_debug file fails to open") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10perf/core: Fix child_total_time_enabled accounting bug at task exitYeoreum Yun
[ Upstream commit a3c3c66670cee11eb13aa43905904bf29cb92d32 ] The perf events code fails to account for total_time_enabled of inactive events. Here is a failure case for accounting total_time_enabled for CPU PMU events: sudo ./perf stat -vvv -e armv8_pmuv3_0/event=0x08/ -e armv8_pmuv3_1/event=0x08/ -- stress-ng --pthread=2 -t 2s ... armv8_pmuv3_0/event=0x08/: 1138698008 2289429840 2174835740 armv8_pmuv3_1/event=0x08/: 1826791390 1950025700 847648440 ` ` ` ` ` > total_time_running with child ` > total_time_enabled with child > count with child Performance counter stats for 'stress-ng --pthread=2 -t 2s': 1,138,698,008 armv8_pmuv3_0/event=0x08/ (94.99%) 1,826,791,390 armv8_pmuv3_1/event=0x08/ (43.47%) The two events above are opened on two different CPU PMUs, for example, each event is opened for a cluster in an Arm big.LITTLE system, they will never run on the same CPU. In theory, the total enabled time should be same for both events, as two events are opened and closed together. As the result show, the two events' total enabled time including child event is different (2289429840 vs 1950025700). This is because child events are not accounted properly if a event is INACTIVE state when the task exits: perf_event_exit_event() `> perf_remove_from_context() `> __perf_remove_from_context() `> perf_child_detach() -> Accumulate child_total_time_enabled `> list_del_event() -> Update child event's time The problem is the time accumulation happens prior to child event's time updating. Thus, it misses to account the last period's time when the event exits. The perf core layer follows the rule that timekeeping is tied to state change. To address the issue, make __perf_remove_from_context() handle the task exit case by passing 'DETACH_EXIT' to it and invoke perf_event_state() for state alongside with accounting the time. Then, perf_child_detach() populates the time into the parent's time metrics. After this patch, the bug is fixed: sudo ./perf stat -vvv -e armv8_pmuv3_0/event=0x08/ -e armv8_pmuv3_1/event=0x08/ -- stress-ng --pthread=2 -t 10s ... armv8_pmuv3_0/event=0x08/: 15396770398 32157963940 21898169000 armv8_pmuv3_1/event=0x08/: 22428964974 32157963940 10259794940 Performance counter stats for 'stress-ng --pthread=2 -t 10s': 15,396,770,398 armv8_pmuv3_0/event=0x08/ (68.10%) 22,428,964,974 armv8_pmuv3_1/event=0x08/ (31.90%) [ mingo: Clarified the changelog. ] Fixes: ef54c1a476aef ("perf: Rework perf_event_exit_event()") Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Leo Yan <leo.yan@arm.com> Link: https://lore.kernel.org/r/20250326082003.1630986-1-yeoreum.yun@arm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10locking/semaphore: Use wake_q to wake up processes outside lock critical sectionWaiman Long
[ Upstream commit 85b2b9c16d053364e2004883140538e73b333cdb ] A circular lock dependency splat has been seen involving down_trylock(): ====================================================== WARNING: possible circular locking dependency detected 6.12.0-41.el10.s390x+debug ------------------------------------------------------ dd/32479 is trying to acquire lock: 0015a20accd0d4f8 ((console_sem).lock){-.-.}-{2:2}, at: down_trylock+0x26/0x90 but task is already holding lock: 000000017e461698 (&zone->lock){-.-.}-{2:2}, at: rmqueue_bulk+0xac/0x8f0 the existing dependency chain (in reverse order) is: -> #4 (&zone->lock){-.-.}-{2:2}: -> #3 (hrtimer_bases.lock){-.-.}-{2:2}: -> #2 (&rq->__lock){-.-.}-{2:2}: -> #1 (&p->pi_lock){-.-.}-{2:2}: -> #0 ((console_sem).lock){-.-.}-{2:2}: The console_sem -> pi_lock dependency is due to calling try_to_wake_up() while holding the console_sem raw_spinlock. This dependency can be broken by using wake_q to do the wakeup instead of calling try_to_wake_up() under the console_sem lock. This will also make the semaphore's raw_spinlock become a terminal lock without taking any further locks underneath it. The hrtimer_bases.lock is a raw_spinlock while zone->lock is a spinlock. The hrtimer_bases.lock -> zone->lock dependency happens via the debug_objects_fill_pool() helper function in the debugobjects code. -> #4 (&zone->lock){-.-.}-{2:2}: __lock_acquire+0xe86/0x1cc0 lock_acquire.part.0+0x258/0x630 lock_acquire+0xb8/0xe0 _raw_spin_lock_irqsave+0xb4/0x120 rmqueue_bulk+0xac/0x8f0 __rmqueue_pcplist+0x580/0x830 rmqueue_pcplist+0xfc/0x470 rmqueue.isra.0+0xdec/0x11b0 get_page_from_freelist+0x2ee/0xeb0 __alloc_pages_noprof+0x2c2/0x520 alloc_pages_mpol_noprof+0x1fc/0x4d0 alloc_pages_noprof+0x8c/0xe0 allocate_slab+0x320/0x460 ___slab_alloc+0xa58/0x12b0 __slab_alloc.isra.0+0x42/0x60 kmem_cache_alloc_noprof+0x304/0x350 fill_pool+0xf6/0x450 debug_object_activate+0xfe/0x360 enqueue_hrtimer+0x34/0x190 __run_hrtimer+0x3c8/0x4c0 __hrtimer_run_queues+0x1b2/0x260 hrtimer_interrupt+0x316/0x760 do_IRQ+0x9a/0xe0 do_irq_async+0xf6/0x160 Normally a raw_spinlock to spinlock dependency is not legitimate and will be warned if CONFIG_PROVE_RAW_LOCK_NESTING is enabled, but debug_objects_fill_pool() is an exception as it explicitly allows this dependency for non-PREEMPT_RT kernel without causing PROVE_RAW_LOCK_NESTING lockdep splat. As a result, this dependency is legitimate and not a bug. Anyway, semaphore is the only locking primitive left that is still using try_to_wake_up() to do wakeup inside critical section, all the other locking primitives had been migrated to use wake_q to do wakeup outside of the critical section. It is also possible that there are other circular locking dependencies involving printk/console_sem or other existing/new semaphores lurking somewhere which may show up in the future. Let just do the migration now to wake_q to avoid headache like this. Reported-by: yzbot+ed801a886dfdbfe7136d@syzkaller.appspotmail.com Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250307232717.1759087-3-boqun.feng@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10sched/deadline: Use online cpus for validating runtimeShrikanth Hegde
[ Upstream commit 14672f059d83f591afb2ee1fff56858efe055e5a ] The ftrace selftest reported a failure because writing -1 to sched_rt_runtime_us returns -EBUSY. This happens when the possible CPUs are different from active CPUs. Active CPUs are part of one root domain, while remaining CPUs are part of def_root_domain. Since active cpumask is being used, this results in cpus=0 when a non active CPUs is used in the loop. Fix it by looping over the online CPUs instead for validating the bandwidth calculations. Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Juri Lelli <juri.lelli@redhat.com> Link: https://lore.kernel.org/r/20250306052954.452005-2-sshegde@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10perf/core: Fix perf_pmu_register() vs. perf_init_event()Peter Zijlstra
[ Upstream commit 003659fec9f6d8c04738cb74b5384398ae8a7e88 ] There is a fairly obvious race between perf_init_event() doing idr_find() and perf_pmu_register() doing idr_alloc() with an incompletely initialized PMU pointer. Avoid by doing idr_alloc() on a NULL pointer to register the id, and swizzling the real struct pmu pointer at the end using idr_replace(). Also making sure to not set struct pmu members after publishing the struct pmu, duh. [ introduce idr_cmpxchg() in order to better handle the idr_replace() error case -- if it were to return an unexpected pointer, it will already have replaced the value and there is no going back. ] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20241104135517.858805880@infradead.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10ring-buffer: Fix bytes_dropped calculation issueFeng Yang
[ Upstream commit c73f0b69648501978e8b3e8fa7eef7f4197d0481 ] The calculation of bytes-dropped and bytes_dropped_nested is reversed. Although it does not affect the final calculation of total_dropped, it should still be modified. Link: https://lore.kernel.org/20250223070106.6781-1-yangfeng59949@163.com Fixes: 6c43e554a2a5 ("ring-buffer: Add ring buffer startup selftest") Signed-off-by: Feng Yang <yangfeng@kylinos.cn> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10kexec: initialize ELF lowest address to ULONG_MAXSourabh Jain
[ Upstream commit 9986fb5164c8b21f6439cfd45ba36d8cc80c9710 ] Patch series "powerpc/crash: use generic crashkernel reservation", v3. Commit 0ab97169aa05 ("crash_core: add generic function to do reservation") added a generic function to reserve crashkernel memory. So let's use the same function on powerpc and remove the architecture-specific code that essentially does the same thing. The generic crashkernel reservation also provides a way to split the crashkernel reservation into high and low memory reservations, which can be enabled for powerpc in the future. Additionally move powerpc to use generic APIs to locate memory hole for kexec segments while loading kdump kernel. This patch (of 7): kexec_elf_load() loads an ELF executable and sets the address of the lowest PT_LOAD section to the address held by the lowest_load_addr function argument. To determine the lowest PT_LOAD address, a local variable lowest_addr (type unsigned long) is initialized to UINT_MAX. After loading each PT_LOAD, its address is compared to lowest_addr. If a loaded PT_LOAD address is lower, lowest_addr is updated. However, setting lowest_addr to UINT_MAX won't work when the kernel image is loaded above 4G, as the returned lowest PT_LOAD address would be invalid. This is resolved by initializing lowest_addr to ULONG_MAX instead. This issue was discovered while implementing crashkernel high/low reservation on the PowerPC architecture. Link: https://lkml.kernel.org/r/20250131113830.925179-1-sourabhjain@linux.ibm.com Link: https://lkml.kernel.org/r/20250131113830.925179-2-sourabhjain@linux.ibm.com Fixes: a0458284f062 ("powerpc: Add support code for kexec_file_load()") Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com> Acked-by: Hari Bathini <hbathini@linux.ibm.com> Acked-by: Baoquan He <bhe@redhat.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mahesh Salgaonkar <mahesh@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10kernel/events/uprobes: handle device-exclusive entries correctly in ↵David Hildenbrand
__replace_page() [ Upstream commit 096cbb80ab3fd85a9035ec17a1312c2a7db8bc8c ] Ever since commit b756a3b5e7ea ("mm: device exclusive memory access") we can return with a device-exclusive entry from page_vma_mapped_walk(). __replace_page() is not prepared for that, so teach it about these PFN swap PTEs. Note that device-private entries are so far not applicable on that path, because GUP would never have returned such folios (conversion to device-private happens by page migration, not in-place conversion of the PTE). There is a race between GUP and us locking the folio to look it up using page_vma_mapped_walk(), so this is likely a fix (unless something else could prevent that race, but it doesn't look like). pte_pfn() on something that is not a present pte could give use garbage, and we'd wrongly mess up the mapcount because it was already adjusted by calling folio_remove_rmap_pte() when making the entry device-exclusive. Link: https://lkml.kernel.org/r/20250210193801.781278-9-david@redhat.com Fixes: b756a3b5e7ea ("mm: device exclusive memory access") Signed-off-by: David Hildenbrand <david@redhat.com> Tested-by: Alistair Popple <apopple@nvidia.com> Cc: Alex Shi <alexs@kernel.org> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Dave Airlie <airlied@gmail.com> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Karol Herbst <kherbst@redhat.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Lyude <lyude@redhat.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: SeongJae Park <sj@kernel.org> Cc: Simona Vetter <simona.vetter@ffwll.ch> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yanteng Si <si.yanteng@linux.dev> Cc: Barry Song <v-songbaohua@oppo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10bpf: Use preempt_count() directly in bpf_send_signal_common()Hou Tao
[ Upstream commit b4a8b5bba712a711d8ca1f7d04646db63f9c88f5 ] bpf_send_signal_common() uses preemptible() to check whether or not the current context is preemptible. If it is preemptible, it will use irq_work to send the signal asynchronously instead of trying to hold a spin-lock, because spin-lock is sleepable under PREEMPT_RT. However, preemptible() depends on CONFIG_PREEMPT_COUNT. When CONFIG_PREEMPT_COUNT is turned off (e.g., CONFIG_PREEMPT_VOLUNTARY=y), !preemptible() will be evaluated as 1 and bpf_send_signal_common() will use irq_work unconditionally. Fix it by unfolding "!preemptible()" and using "preempt_count() != 0 || irqs_disabled()" instead. Fixes: 87c544108b61 ("bpf: Send signals asynchronously if !preemptible") Signed-off-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/20250220042259.1583319-1-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10x86/mm/pat: Fix VM_PAT handling when fork() fails in copy_page_range()David Hildenbrand
[ Upstream commit dc84bc2aba85a1508f04a936f9f9a15f64ebfb31 ] If track_pfn_copy() fails, we already added the dst VMA to the maple tree. As fork() fails, we'll cleanup the maple tree, and stumble over the dst VMA for which we neither performed any reservation nor copied any page tables. Consequently untrack_pfn() will see VM_PAT and try obtaining the PAT information from the page table -- which fails because the page table was not copied. The easiest fix would be to simply clear the VM_PAT flag of the dst VMA if track_pfn_copy() fails. However, the whole thing is about "simply" clearing the VM_PAT flag is shaky as well: if we passed track_pfn_copy() and performed a reservation, but copying the page tables fails, we'll simply clear the VM_PAT flag, not properly undoing the reservation ... which is also wrong. So let's fix it properly: set the VM_PAT flag only if the reservation succeeded (leaving it clear initially), and undo the reservation if anything goes wrong while copying the page tables: clearing the VM_PAT flag after undoing the reservation. Note that any copied page table entries will get zapped when the VMA will get removed later, after copy_page_range() succeeded; as VM_PAT is not set then, we won't try cleaning VM_PAT up once more and untrack_pfn() will be happy. Note that leaving these page tables in place without a reservation is not a problem, as we are aborting fork(); this process will never run. A reproducer can trigger this usually at the first try: https://gitlab.com/davidhildenbrand/scratchspace/-/raw/main/reproducers/pat_fork.c WARNING: CPU: 26 PID: 11650 at arch/x86/mm/pat/memtype.c:983 get_pat_info+0xf6/0x110 Modules linked in: ... CPU: 26 UID: 0 PID: 11650 Comm: repro3 Not tainted 6.12.0-rc5+ #92 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40 04/01/2014 RIP: 0010:get_pat_info+0xf6/0x110 ... Call Trace: <TASK> ... untrack_pfn+0x52/0x110 unmap_single_vma+0xa6/0xe0 unmap_vmas+0x105/0x1f0 exit_mmap+0xf6/0x460 __mmput+0x4b/0x120 copy_process+0x1bf6/0x2aa0 kernel_clone+0xab/0x440 __do_sys_clone+0x66/0x90 do_syscall_64+0x95/0x180 Likely this case was missed in: d155df53f310 ("x86/mm/pat: clear VM_PAT if copy_p4d_range failed") ... and instead of undoing the reservation we simply cleared the VM_PAT flag. Keep the documentation of these functions in include/linux/pgtable.h, one place is more than sufficient -- we should clean that up for the other functions like track_pfn_remap/untrack_pfn separately. Fixes: d155df53f310 ("x86/mm/pat: clear VM_PAT if copy_p4d_range failed") Fixes: 2ab640379a0a ("x86: PAT: hooks in generic vm code to help archs to track pfnmap regions - v3") Reported-by: xingwei lee <xrivendell7@gmail.com> Reported-by: yuxin wang <wang1315768607@163.com> Reported-by: Marius Fleischer <fleischermarius@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mm@kvack.org Link: https://lore.kernel.org/r/20250321112323.153741-1-david@redhat.com Closes: https://lore.kernel.org/lkml/CABOYnLx_dnqzpCW99G81DmOr+2UzdmZMk=T3uxwNxwz+R1RAwg@mail.gmail.com/ Closes: https://lore.kernel.org/lkml/CAJg=8jwijTP5fre8woS4JVJQ8iUA6v+iNcsOgtj9Zfpc3obDOQ@mail.gmail.com/ Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10perf/ring_buffer: Allow the EPOLLRDNORM flag for pollTao Chen
[ Upstream commit c96fff391c095c11dc87dab35be72dee7d217cde ] The poll man page says POLLRDNORM is equivalent to POLLIN. For poll(), it seems that if user sets pollfd with POLLRDNORM in userspace, perf_poll will not return until timeout even if perf_output_wakeup called, whereas POLLIN returns. Fixes: 76369139ceb9 ("perf: Split up buffer handling from core code") Signed-off-by: Tao Chen <chen.dylane@linux.dev> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250314030036.2543180-1-chen.dylane@linux.dev Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10watch_queue: fix pipe accounting mismatchEric Sandeen
[ Upstream commit f13abc1e8e1a3b7455511c4e122750127f6bc9b0 ] Currently, watch_queue_set_size() modifies the pipe buffers charged to user->pipe_bufs without updating the pipe->nr_accounted on the pipe itself, due to the if (!pipe_has_watch_queue()) test in pipe_resize_ring(). This means that when the pipe is ultimately freed, we decrement user->pipe_bufs by something other than what than we had charged to it, potentially leading to an underflow. This in turn can cause subsequent too_many_pipe_buffers_soft() tests to fail with -EPERM. To remedy this, explicitly account for the pipe usage in watch_queue_set_size() to match the number set via account_pipe_buffers() (It's unclear why watch_queue_set_size() does not update nr_accounted; it may be due to intentional overprovisioning in watch_queue_set_size()?) Fixes: e95aada4cb93d ("pipe: wakeup wr_wait after setting max_usage") Signed-off-by: Eric Sandeen <sandeen@redhat.com> Link: https://lore.kernel.org/r/206682a8-0604-49e5-8224-fdbe0c12b460@redhat.com Signed-off-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
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