Messages in this thread | | | Date | Tue, 27 Feb 2024 11:25:02 +0800 | Subject | Re: [PATCH] perf: RISCV: Fix panic on pmu overflow handler | From | "Wu, Fei" <> |
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On 2/27/2024 11:07 AM, Fei Wu wrote: > Sign extension of (1 << idx) from int is not desired when setting bits > in unsigned long overflowed_ctrs, kernel panics if 31 is a valid lidx. > This panic happens when 'perf record -e branches' on a sophgo machine. > Sign extension is the reason for this specific panic, in general it's wrong if lidx >= 31.
Thanks, Fei.
> [ 212.845953] epc : ffffffff80afc288 ra : ffffffff80afd310 sp : fffffff6e36928f0 > [ 212.853474] gp : ffffffff821f7f48 tp : ffffffd9033b9900 t0 : 0000002ad69e9978 > [ 212.861069] t1 : 000000000000002a t2 : ffffffff801764d2 s0 : fffffff6e3692ab0 > [ 212.868637] s1 : 0000000000000020 a0 : 0000000000000000 a1 : 0000000000000015 > [ 212.876021] a2 : 0000000000000000 a3 : 0000000000000015 a4 : 0000000000000020 > [ 212.883482] a5 : ffffffd7ff880640 a6 : 000000000005a569 a7 : ffffffffffffffd5 > [ 212.891191] s2 : 000000000000ffff s3 : 0000000000000000 s4 : ffffffd7ff880540 > [ 212.898707] s5 : 0000000000504d55 s6 : ffffffd902443000 s7 : ffffffff821fe1f8 > [ 212.906329] s8 : 000000007fffffff s9 : ffffffd7ff880540 s10: ffffffd9147a1098 > [ 212.914151] s11: 0000000080000000 t3 : 0000000000000003 t4 : ffffffff80186226 > [ 212.921773] t5 : ffffffff802455ca t6 : ffffffd9058900e8 > [ 212.927300] status: 0000000200000100 badaddr: 0000000000000098 cause: 000000000000000d > [ 212.935575] [<ffffffff80afc288>] riscv_pmu_ctr_get_width_mask+0x8/0x60 > [ 212.942391] [<ffffffff80079922>] handle_percpu_devid_irq+0x98/0x1e8 > [ 212.948855] [<ffffffff80073d06>] generic_handle_domain_irq+0x28/0x36 > [ 212.955521] [<ffffffff80481444>] riscv_intc_irq+0x36/0x4e > [ 212.961269] [<ffffffff80ca5fce>] handle_riscv_irq+0x4a/0x74 > [ 212.967270] [<ffffffff80ca6afc>] do_irq+0x60/0x90 > [ 212.972284] Code: b580 60a2 6402 5529 0141 8082 0013 0000 0013 0000 (6d5c) b783 > [ 212.980036] ---[ end trace 0000000000000000 ]--- > [ 212.984874] Kernel panic - not syncing: Fatal exception in interrupt > [ 212.991506] SMP: stopping secondary CPUs > [ 212.995964] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]--- > > Signed-off-by: Fei Wu <fei2.wu@intel.com> > --- > drivers/perf/riscv_pmu_sbi.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c > index 16acd4dcdb96..c87c459e52de 100644 > --- a/drivers/perf/riscv_pmu_sbi.c > +++ b/drivers/perf/riscv_pmu_sbi.c > @@ -731,14 +731,14 @@ static irqreturn_t pmu_sbi_ovf_handler(int irq, void *dev) > /* compute hardware counter index */ > hidx = info->csr - CSR_CYCLE; > /* check if the corresponding bit is set in sscountovf */ > - if (!(overflow & (1 << hidx))) > + if (!(overflow & (1UL << hidx))) > continue; > > /* > * Keep a track of overflowed counters so that they can be started > * with updated initial value. > */ > - overflowed_ctrs |= 1 << lidx; > + overflowed_ctrs |= 1UL << lidx; > hw_evt = &event->hw; > riscv_pmu_event_update(event); > perf_sample_data_init(&data, 0, hw_evt->last_period);
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