Message ID | 20231109082128.40777-1-alexghiti@rivosinc.com (mailing list archive) |
---|---|
State | Accepted |
Commit | c6e316ac05532febb0c966fa9b55f5258ed037be |
Headers | show |
Series | drivers: perf: Check find_first_bit() return value | expand |
On Thu, Nov 9, 2023 at 12:21 AM Alexandre Ghiti <alexghiti@rivosinc.com> wrote: > > 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] [<ffffffff80a0a77c>] pmu_sbi_ovf_handler+0x3a4/0x3ae > [ 107.320112] [<ffffffff800b42d0>] handle_percpu_devid_irq+0x9e/0x1a0 > [ 107.320131] [<ffffffff800ad92c>] generic_handle_domain_irq+0x28/0x36 > [ 107.320148] [<ffffffff8065f9f8>] riscv_intc_irq+0x36/0x4e > [ 107.320166] [<ffffffff80caf4a0>] handle_riscv_irq+0x54/0x86 > [ 107.320189] [<ffffffff80cb0036>] 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 <alexghiti@rivosinc.com> > --- > drivers/perf/riscv_pmu_sbi.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c > index 439da49dd0a9..93d729213140 100644 > --- a/drivers/perf/riscv_pmu_sbi.c > +++ b/drivers/perf/riscv_pmu_sbi.c > @@ -687,6 +687,11 @@ 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)); > -- > 2.39.2 > Reviewed-by: Atish Patra <atishp@rivosinc.com>
Hello: This patch was applied to riscv/linux.git (for-next) by Palmer Dabbelt <palmer@rivosinc.com>: On Thu, 9 Nov 2023 09:21:28 +0100 you wrote: > 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] [<ffffffff80a0a77c>] pmu_sbi_ovf_handler+0x3a4/0x3ae > [ 107.320112] [<ffffffff800b42d0>] handle_percpu_devid_irq+0x9e/0x1a0 > [ 107.320131] [<ffffffff800ad92c>] generic_handle_domain_irq+0x28/0x36 > [ 107.320148] [<ffffffff8065f9f8>] riscv_intc_irq+0x36/0x4e > [ 107.320166] [<ffffffff80caf4a0>] handle_riscv_irq+0x54/0x86 > [ 107.320189] [<ffffffff80cb0036>] 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 ]--- > > [...] Here is the summary with links: - drivers: perf: Check find_first_bit() return value https://git.kernel.org/riscv/c/c6e316ac0553 You are awesome, thank you!
diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c index 439da49dd0a9..93d729213140 100644 --- a/drivers/perf/riscv_pmu_sbi.c +++ b/drivers/perf/riscv_pmu_sbi.c @@ -687,6 +687,11 @@ 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));
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] [<ffffffff80a0a77c>] pmu_sbi_ovf_handler+0x3a4/0x3ae [ 107.320112] [<ffffffff800b42d0>] handle_percpu_devid_irq+0x9e/0x1a0 [ 107.320131] [<ffffffff800ad92c>] generic_handle_domain_irq+0x28/0x36 [ 107.320148] [<ffffffff8065f9f8>] riscv_intc_irq+0x36/0x4e [ 107.320166] [<ffffffff80caf4a0>] handle_riscv_irq+0x54/0x86 [ 107.320189] [<ffffffff80cb0036>] 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 <alexghiti@rivosinc.com> --- drivers/perf/riscv_pmu_sbi.c | 5 +++++ 1 file changed, 5 insertions(+)