From c6e316ac05532febb0c966fa9b55f5258ed037be Mon Sep 17 00:00:00 2001 From: Alexandre Ghiti Date: Thu, 9 Nov 2023 09:21:28 +0100 Subject: drivers: perf: Check find_first_bit() return value We must check the return value of find_first_bit() before using the return value as an index array since it happens to overflow the array and then panic: [ 107.318430] Kernel BUG [#1] [ 107.319434] CPU: 3 PID: 1238 Comm: kill Tainted: G E 6.6.0-rc6ubuntu-defconfig #2 [ 107.319465] Hardware name: riscv-virtio,qemu (DT) [ 107.319551] epc : pmu_sbi_ovf_handler+0x3a4/0x3ae [ 107.319840] ra : pmu_sbi_ovf_handler+0x52/0x3ae [ 107.319868] epc : ffffffff80a0a77c ra : ffffffff80a0a42a sp : ffffaf83fecda350 [ 107.319884] gp : ffffffff823961a8 tp : ffffaf8083db1dc0 t0 : ffffaf83fecda480 [ 107.319899] t1 : ffffffff80cafe62 t2 : 000000000000ff00 s0 : ffffaf83fecda520 [ 107.319921] s1 : ffffaf83fecda380 a0 : 00000018fca29df0 a1 : ffffffffffffffff [ 107.319936] a2 : 0000000001073734 a3 : 0000000000000004 a4 : 0000000000000000 [ 107.319951] a5 : 0000000000000040 a6 : 000000001d1c8774 a7 : 0000000000504d55 [ 107.319965] s2 : ffffffff82451f10 s3 : ffffffff82724e70 s4 : 000000000000003f [ 107.319980] s5 : 0000000000000011 s6 : ffffaf8083db27c0 s7 : 0000000000000000 [ 107.319995] s8 : 0000000000000001 s9 : 00007fffb45d6558 s10: 00007fffb45d81a0 [ 107.320009] s11: ffffaf7ffff60000 t3 : 0000000000000004 t4 : 0000000000000000 [ 107.320023] t5 : ffffaf7f80000000 t6 : ffffaf8000000000 [ 107.320037] status: 0000000200000100 badaddr: 0000000000000000 cause: 0000000000000003 [ 107.320081] [] pmu_sbi_ovf_handler+0x3a4/0x3ae [ 107.320112] [] handle_percpu_devid_irq+0x9e/0x1a0 [ 107.320131] [] generic_handle_domain_irq+0x28/0x36 [ 107.320148] [] riscv_intc_irq+0x36/0x4e [ 107.320166] [] handle_riscv_irq+0x54/0x86 [ 107.320189] [] do_irq+0x64/0x96 [ 107.320271] Code: 85a6 855e b097 ff7f 80e7 9220 b709 9002 4501 bbd9 (9002) 6097 [ 107.320585] ---[ end trace 0000000000000000 ]--- [ 107.320704] Kernel panic - not syncing: Fatal exception in interrupt [ 107.320775] SMP: stopping secondary CPUs [ 107.321219] Kernel Offset: 0x0 from 0xffffffff80000000 [ 107.333051] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]--- Fixes: 4905ec2fb7e6 ("RISC-V: Add sscofpmf extension support") Signed-off-by: Alexandre Ghiti Link: https://lore.kernel.org/r/20231109082128.40777-1-alexghiti@rivosinc.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt --- drivers/perf/riscv_pmu_sbi.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/perf') diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c index 9a51053b1f99..0b5053152ee6 100644 --- a/drivers/perf/riscv_pmu_sbi.c +++ b/drivers/perf/riscv_pmu_sbi.c @@ -685,6 +685,11 @@ static irqreturn_t pmu_sbi_ovf_handler(int irq, void *dev) /* Firmware counter don't support overflow yet */ fidx = find_first_bit(cpu_hw_evt->used_hw_ctrs, RISCV_MAX_COUNTERS); + if (fidx == RISCV_MAX_COUNTERS) { + csr_clear(CSR_SIP, BIT(riscv_pmu_irq_num)); + return IRQ_NONE; + } + event = cpu_hw_evt->events[fidx]; if (!event) { csr_clear(CSR_SIP, BIT(riscv_pmu_irq_num)); -- cgit v1.2.3