drivers: perf: Do not broadcast to other cpus when starting a counter

In the Linux kernel, the following vulnerability has been resolved: drivers: perf: Do not broadcast to other cpus when starting a counter This command: $ perf record -e cycles:k -e instructions:k -c 10000 -m 64M dd if=/dev/zero of=/dev/null count=1000 gives rise to this kernel warning: [ 444.364395] WARNING: CPU: 0 PID: 104 at kernel/smp.c:775 smp_call_function_many_cond+0x42c/0x436 [ 444.364515] Modules linked in: [ 444.364657] CPU: 0 PID: 104 Comm: perf-exec Not tainted 6.6.0-rc6-00051-g391df82e8ec3-dirty #73 [ 444.364771] Hardware name: riscv-virtio,qemu (DT) [ 444.364868] epc : smp_call_function_many_cond+0x42c/0x436 [ 444.364917] ra : on_each_cpu_cond_mask+0x20/0x32 [ 444.364948] epc : ffffffff8009f9e0 ra : ffffffff8009fa5a sp : ff20000000003800 [ 444.364966] gp : ffffffff81500aa0 tp : ff60000002b83000 t0 : ff200000000038c0 [ 444.364982] t1 : ffffffff815021f0 t2 : 000000000000001f s0 : ff200000000038b0 [ 444.364998] s1 : ff60000002c54d98 a0 : ff60000002a73940 a1 : 0000000000000000 [ 444.365013] a2 : 0000000000000000 a3 : 0000000000000003 a4 : 0000000000000100 [ 444.365029] a5 : 0000000000010100 a6 : 0000000000f00000 a7 : 0000000000000000 [ 444.365044] s2 : 0000000000000000 s3 : ffffffffffffffff s4 : ff60000002c54d98 [ 444.365060] s5 : ffffffff81539610 s6 : ffffffff80c20c48 s7 : 0000000000000000 [ 444.365075] s8 : 0000000000000000 s9 : 0000000000000001 s10: 0000000000000001 [ 444.365090] s11: ffffffff80099394 t3 : 0000000000000003 t4 : 00000000eac0c6e6 [ 444.365104] t5 : 0000000400000000 t6 : ff60000002e010d0 [ 444.365120] status: 0000000200000100 badaddr: 0000000000000000 cause: 0000000000000003 [ 444.365226] [<ffffffff8009f9e0>] smp_call_function_many_cond+0x42c/0x436 [ 444.365295] [<ffffffff8009fa5a>] on_each_cpu_cond_mask+0x20/0x32 [ 444.365311] [<ffffffff806e90dc>] pmu_sbi_ctr_start+0x7a/0xaa [ 444.365327] [<ffffffff806e880c>] riscv_pmu_start+0x48/0x66 [ 444.365339] [<ffffffff8012111a>] perf_adjust_freq_unthr_context+0x196/0x1ac [ 444.365356] [<ffffffff801237aa>] perf_event_task_tick+0x78/0x8c [ 444.365368] [<ffffffff8003faf4>] scheduler_tick+0xe6/0x25e [ 444.365383] [<ffffffff8008a042>] update_process_times+0x80/0x96 [ 444.365398] [<ffffffff800991ec>] tick_sched_handle+0x26/0x52 [ 444.365410] [<ffffffff800993e4>] tick_sched_timer+0x50/0x98 [ 444.365422] [<ffffffff8008a6aa>] __hrtimer_run_queues+0x126/0x18a [ 444.365433] [<ffffffff8008b350>] hrtimer_interrupt+0xce/0x1da [ 444.365444] [<ffffffff806cdc60>] riscv_timer_interrupt+0x30/0x3a [ 444.365457] [<ffffffff8006afa6>] handle_percpu_devid_irq+0x80/0x114 [ 444.365470] [<ffffffff80065b82>] generic_handle_domain_irq+0x1c/0x2a [ 444.365483] [<ffffffff8045faec>] riscv_intc_irq+0x2e/0x46 [ 444.365497] [<ffffffff808a9c62>] handle_riscv_irq+0x4a/0x74 [ 444.365521] [<ffffffff808aa760>] do_irq+0x7c/0x7e [ 444.365796] ---[ end trace 0000000000000000 ]--- That's because the fix in commit 3fec323339a4 ("drivers: perf: Fix panic in riscv SBI mmap support") was wrong since there is no need to broadcast to other cpus when starting a counter, that's only needed in mmap when the counters could have already been started on other cpus, so simply remove this broadcast.

Опубликовано

21 мая 2024 г.

Обновлено

17 июн. 2026 г.

EPSS

0,2 % · 10-й процентиль

CWE

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