We found this problem in our kernel src tree:
[ 14.816231] ------------[ cut here ]------------ [ 14.816231] kernel BUG at irq.c:99! [ 14.816232] Internal error: Oops - BUG: 0 [#1] SMP [ 14.816232] Process swapper/0 (pid: 0, stack limit = 0x(____ptrval____)) [ 14.816233] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G O 4.19.95.aarch64 #14 [ 14.816233] Hardware name: evb (DT) [ 14.816234] pstate: 80400085 (Nzcv daIf +PAN -UAO) [ 14.816234] pc : asm_nmi_enter+0x94/0x98 [ 14.816235] lr : asm_nmi_enter+0x18/0x98 [ 14.816235] sp : ffff000008003c50 [ 14.816235] pmr_save: 00000070 [ 14.816237] x29: ffff000008003c50 x28: ffff0000095f56c0 [ 14.816238] x27: 0000000000000000 x26: ffff000008004000 [ 14.816239] x25: 00000000015e0000 x24: ffff8008fb916000 [ 14.816240] x23: 0000000020400005 x22: ffff0000080817cc [ 14.816241] x21: ffff000008003da0 x20: 0000000000000060 [ 14.816242] x19: 00000000000003ff x18: ffffffffffffffff [ 14.816243] x17: 0000000000000008 x16: 003d090000000000 [ 14.816244] x15: ffff0000095ea6c8 x14: ffff8008fff5ab40 [ 14.816244] x13: ffff8008fff58b9d x12: 0000000000000000 [ 14.816245] x11: ffff000008c8a200 x10: 000000008e31fca5 [ 14.816246] x9 : ffff000008c8a208 x8 : 000000000000000f [ 14.816247] x7 : 0000000000000004 x6 : ffff8008fff58b9e [ 14.816248] x5 : 0000000000000000 x4 : 0000000080000000 [ 14.816249] x3 : 0000000000000000 x2 : 0000000080000000 [ 14.816250] x1 : 0000000000120000 x0 : ffff0000095f56c0 [ 14.816251] Call trace: [ 14.816251] asm_nmi_enter+0x94/0x98 [ 14.816251] el1_irq+0x8c/0x180 (IRQ C) [ 14.816252] gic_handle_irq+0xbc/0x2e4 [ 14.816252] el1_irq+0xcc/0x180 (IRQ B) [ 14.816253] arch_timer_handler_virt+0x38/0x58 [ 14.816253] handle_percpu_devid_irq+0x90/0x240 [ 14.816253] generic_handle_irq+0x34/0x50 [ 14.816254] __handle_domain_irq+0x68/0xc0 [ 14.816254] gic_handle_irq+0xf8/0x2e4 [ 14.816255] el1_irq+0xcc/0x180 (IRQ A) [ 14.816255] arch_cpu_idle+0x34/0x1c8 [ 14.816255] default_idle_call+0x24/0x44 [ 14.816256] do_idle+0x1d0/0x2c8 [ 14.816256] cpu_startup_entry+0x28/0x30 [ 14.816256] rest_init+0xb8/0xc8 [ 14.816257] start_kernel+0x4c8/0x4f4 [ 14.816257] Code: 940587f1 d5384100 b9401001 36a7fd01 (d4210000) [ 14.816258] Modules linked in: start_dp(O) smeth(O) [ 15.103092] ---[ end trace 701753956cb14aa8 ]--- [ 15.103093] Kernel panic - not syncing: Fatal exception in interrupt [ 15.103099] SMP: stopping secondary CPUs [ 15.103100] Kernel Offset: disabled [ 15.103100] CPU features: 0x36,a2400218 [ 15.103100] Memory Limit: none
I look into this issue and find that it's caused by 'BUG_ON(in_nmi())' in nmi_enter(). From the call trace, we can find three interrupts which I mark as IRQ A, B and C. By adding some prints, I find the IRQ B also calls nmi_enter(), but its priority is not GICD_INT_NMI_PRI and its irq number is 1023. It enables irq by calling gic_arch_enable_irqs() in gic_handle_irq(). At this moment, IRQ C preempts the IRQ B and it's an NMI but current context is already in nmi. So that may be the problem.
When handling spurious interrupts, we shouldn't enable irqs. That's because for spurious interrupts we may enter nmi context in el1_irq() because current PMR may be GIC_PRIO_IRQOFF. If we enable irqs at this time, another NMI may happen and preempt this spurious interrupt but the context is already in nmi. That causes a bug on if nested NMI is not supported. Even for nested nmi, it's not a normal scenario.
Though the issue is reported on our private tree, I think it also exists on the latest tree for the reasons above. To fix this issue, check spurious interrupts right after the read of ICC_IAR1_EL1 and return directly for spurious interrupts.
Fixes: 17ce302f3117 ("arm64: Fix interrupt tracing in the presence of NMIs") Signed-off-by: He Ying heying24@huawei.com ---
v2: - Move the check right after the read of ICC_IAR1_EL1 suggested by Marc.
drivers/irqchip/irq-gic-v3.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index 94b89258d045..37a23aa6de37 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -648,6 +648,10 @@ static asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs
irqnr = gic_read_iar();
+ /* Check for special IDs first */ + if ((irqnr >= 1020 && irqnr <= 1023)) + return; + if (gic_supports_nmi() && unlikely(gic_read_rpr() == GICD_INT_NMI_PRI)) { gic_handle_nmi(irqnr, regs); @@ -659,10 +663,6 @@ static asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs gic_arch_enable_irqs(); }
- /* Check for special IDs first */ - if ((irqnr >= 1020 && irqnr <= 1023)) - return; - if (static_branch_likely(&supports_deactivate_key)) gic_write_eoir(irqnr); else
The following commit has been merged into the irq/irqchip-next branch of irqchip:
Commit-ID: dd223f479a5b2cba5ba5c0afddf726df02a4f08f Gitweb: https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms/dd223f479a... Author: He Ying heying24@huawei.com AuthorDate: Fri, 23 Apr 2021 04:35:16 -04:00 Committer: Marc Zyngier maz@kernel.org CommitterDate: Fri, 23 Apr 2021 10:55:48 +01:00
irqchip/gic-v3: Do not enable irqs when handling spurious interrups
We triggered the following error while running our 4.19 kernel with the pseudo-NMI patches backported to it:
[ 14.816231] ------------[ cut here ]------------ [ 14.816231] kernel BUG at irq.c:99! [ 14.816232] Internal error: Oops - BUG: 0 [#1] SMP [ 14.816232] Process swapper/0 (pid: 0, stack limit = 0x(____ptrval____)) [ 14.816233] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G O 4.19.95.aarch64 #14 [ 14.816233] Hardware name: evb (DT) [ 14.816234] pstate: 80400085 (Nzcv daIf +PAN -UAO) [ 14.816234] pc : asm_nmi_enter+0x94/0x98 [ 14.816235] lr : asm_nmi_enter+0x18/0x98 [ 14.816235] sp : ffff000008003c50 [ 14.816235] pmr_save: 00000070 [ 14.816237] x29: ffff000008003c50 x28: ffff0000095f56c0 [ 14.816238] x27: 0000000000000000 x26: ffff000008004000 [ 14.816239] x25: 00000000015e0000 x24: ffff8008fb916000 [ 14.816240] x23: 0000000020400005 x22: ffff0000080817cc [ 14.816241] x21: ffff000008003da0 x20: 0000000000000060 [ 14.816242] x19: 00000000000003ff x18: ffffffffffffffff [ 14.816243] x17: 0000000000000008 x16: 003d090000000000 [ 14.816244] x15: ffff0000095ea6c8 x14: ffff8008fff5ab40 [ 14.816244] x13: ffff8008fff58b9d x12: 0000000000000000 [ 14.816245] x11: ffff000008c8a200 x10: 000000008e31fca5 [ 14.816246] x9 : ffff000008c8a208 x8 : 000000000000000f [ 14.816247] x7 : 0000000000000004 x6 : ffff8008fff58b9e [ 14.816248] x5 : 0000000000000000 x4 : 0000000080000000 [ 14.816249] x3 : 0000000000000000 x2 : 0000000080000000 [ 14.816250] x1 : 0000000000120000 x0 : ffff0000095f56c0 [ 14.816251] Call trace: [ 14.816251] asm_nmi_enter+0x94/0x98 [ 14.816251] el1_irq+0x8c/0x180 (IRQ C) [ 14.816252] gic_handle_irq+0xbc/0x2e4 [ 14.816252] el1_irq+0xcc/0x180 (IRQ B) [ 14.816253] arch_timer_handler_virt+0x38/0x58 [ 14.816253] handle_percpu_devid_irq+0x90/0x240 [ 14.816253] generic_handle_irq+0x34/0x50 [ 14.816254] __handle_domain_irq+0x68/0xc0 [ 14.816254] gic_handle_irq+0xf8/0x2e4 [ 14.816255] el1_irq+0xcc/0x180 (IRQ A) [ 14.816255] arch_cpu_idle+0x34/0x1c8 [ 14.816255] default_idle_call+0x24/0x44 [ 14.816256] do_idle+0x1d0/0x2c8 [ 14.816256] cpu_startup_entry+0x28/0x30 [ 14.816256] rest_init+0xb8/0xc8 [ 14.816257] start_kernel+0x4c8/0x4f4 [ 14.816257] Code: 940587f1 d5384100 b9401001 36a7fd01 (d4210000) [ 14.816258] Modules linked in: start_dp(O) smeth(O) [ 15.103092] ---[ end trace 701753956cb14aa8 ]--- [ 15.103093] Kernel panic - not syncing: Fatal exception in interrupt [ 15.103099] SMP: stopping secondary CPUs [ 15.103100] Kernel Offset: disabled [ 15.103100] CPU features: 0x36,a2400218 [ 15.103100] Memory Limit: none
which is cause by a 'BUG_ON(in_nmi())' in nmi_enter().
From the call trace, we can find three interrupts (noted A, B, C above):
interrupt (A) is preempted by (B), which is further interrupted by (C).
Subsequent investigations show that (B) results in nmi_enter() being called, but that it actually is a spurious interrupt. Furthermore, interrupts are reenabled in the context of (B), and (C) fires with NMI priority. We end-up with a nested NMI situation, something we definitely do not want to (and cannot) handle.
The bug here is that spurious interrupts should never result in any state change, and we should just return to the interrupted context. Moving the handling of spurious interrupts as early as possible in the GICv3 handler fixes this issue.
Fixes: 3f1f3234bc2d ("irqchip/gic-v3: Switch to PMR masking before calling IRQ handler") Signed-off-by: He Ying heying24@huawei.com [maz: rewrote commit message, corrected Fixes: tag] Signed-off-by: Marc Zyngier maz@kernel.org Link: https://lore.kernel.org/r/20210423083516.170111-1-heying24@huawei.com Cc: stable@vger.kernel.org --- drivers/irqchip/irq-gic-v3.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index eb0ee35..0040402 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -648,6 +648,10 @@ static asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs
irqnr = gic_read_iar();
+ /* Check for special IDs first */ + if ((irqnr >= 1020 && irqnr <= 1023)) + return; + if (gic_supports_nmi() && unlikely(gic_read_rpr() == GICD_INT_NMI_PRI)) { gic_handle_nmi(irqnr, regs); @@ -659,10 +663,6 @@ static asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs gic_arch_enable_irqs(); }
- /* Check for special IDs first */ - if ((irqnr >= 1020 && irqnr <= 1023)) - return; - if (static_branch_likely(&supports_deactivate_key)) gic_write_eoir(irqnr); else
On Fri, Apr 23, 2021 at 04:35:16AM -0400, He Ying wrote:
We found this problem in our kernel src tree:
[ 14.816231] ------------[ cut here ]------------ [ 14.816231] kernel BUG at irq.c:99! [ 14.816232] Internal error: Oops - BUG: 0 [#1] SMP [ 14.816232] Process swapper/0 (pid: 0, stack limit = 0x(____ptrval____)) [ 14.816233] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G O 4.19.95.aarch64 #14 [ 14.816233] Hardware name: evb (DT) [ 14.816234] pstate: 80400085 (Nzcv daIf +PAN -UAO) [ 14.816234] pc : asm_nmi_enter+0x94/0x98 [ 14.816235] lr : asm_nmi_enter+0x18/0x98 [ 14.816235] sp : ffff000008003c50 [ 14.816235] pmr_save: 00000070 [ 14.816237] x29: ffff000008003c50 x28: ffff0000095f56c0 [ 14.816238] x27: 0000000000000000 x26: ffff000008004000 [ 14.816239] x25: 00000000015e0000 x24: ffff8008fb916000 [ 14.816240] x23: 0000000020400005 x22: ffff0000080817cc [ 14.816241] x21: ffff000008003da0 x20: 0000000000000060 [ 14.816242] x19: 00000000000003ff x18: ffffffffffffffff [ 14.816243] x17: 0000000000000008 x16: 003d090000000000 [ 14.816244] x15: ffff0000095ea6c8 x14: ffff8008fff5ab40 [ 14.816244] x13: ffff8008fff58b9d x12: 0000000000000000 [ 14.816245] x11: ffff000008c8a200 x10: 000000008e31fca5 [ 14.816246] x9 : ffff000008c8a208 x8 : 000000000000000f [ 14.816247] x7 : 0000000000000004 x6 : ffff8008fff58b9e [ 14.816248] x5 : 0000000000000000 x4 : 0000000080000000 [ 14.816249] x3 : 0000000000000000 x2 : 0000000080000000 [ 14.816250] x1 : 0000000000120000 x0 : ffff0000095f56c0 [ 14.816251] Call trace: [ 14.816251] asm_nmi_enter+0x94/0x98 [ 14.816251] el1_irq+0x8c/0x180 (IRQ C) [ 14.816252] gic_handle_irq+0xbc/0x2e4 [ 14.816252] el1_irq+0xcc/0x180 (IRQ B) [ 14.816253] arch_timer_handler_virt+0x38/0x58 [ 14.816253] handle_percpu_devid_irq+0x90/0x240 [ 14.816253] generic_handle_irq+0x34/0x50 [ 14.816254] __handle_domain_irq+0x68/0xc0 [ 14.816254] gic_handle_irq+0xf8/0x2e4 [ 14.816255] el1_irq+0xcc/0x180 (IRQ A) [ 14.816255] arch_cpu_idle+0x34/0x1c8 [ 14.816255] default_idle_call+0x24/0x44 [ 14.816256] do_idle+0x1d0/0x2c8 [ 14.816256] cpu_startup_entry+0x28/0x30 [ 14.816256] rest_init+0xb8/0xc8 [ 14.816257] start_kernel+0x4c8/0x4f4 [ 14.816257] Code: 940587f1 d5384100 b9401001 36a7fd01 (d4210000) [ 14.816258] Modules linked in: start_dp(O) smeth(O) [ 15.103092] ---[ end trace 701753956cb14aa8 ]--- [ 15.103093] Kernel panic - not syncing: Fatal exception in interrupt [ 15.103099] SMP: stopping secondary CPUs [ 15.103100] Kernel Offset: disabled [ 15.103100] CPU features: 0x36,a2400218 [ 15.103100] Memory Limit: none
I look into this issue and find that it's caused by 'BUG_ON(in_nmi())' in nmi_enter(). From the call trace, we can find three interrupts which I mark as IRQ A, B and C. By adding some prints, I find the IRQ B also calls nmi_enter(), but its priority is not GICD_INT_NMI_PRI and its irq number is 1023. It enables irq by calling gic_arch_enable_irqs() in gic_handle_irq(). At this moment, IRQ C preempts the IRQ B and it's an NMI but current context is already in nmi. So that may be the problem.
When handling spurious interrupts, we shouldn't enable irqs. That's because for spurious interrupts we may enter nmi context in el1_irq() because current PMR may be GIC_PRIO_IRQOFF. If we enable irqs at this time, another NMI may happen and preempt this spurious interrupt but the context is already in nmi. That causes a bug on if nested NMI is not supported. Even for nested nmi, it's not a normal scenario.
Though the issue is reported on our private tree, I think it also exists on the latest tree for the reasons above. To fix this issue, check spurious interrupts right after the read of ICC_IAR1_EL1 and return directly for spurious interrupts.
Fixes: 17ce302f3117 ("arm64: Fix interrupt tracing in the presence of NMIs") Signed-off-by: He Ying heying24@huawei.com
I'm reckon the fixes tag should probably be either:
Fixes: f32c926651dcd168 ("irqchip/gic-v3: Handle pseudo-NMIs")
... or:
Fixes: 3f1f3234bc2db1c1 (" irqchip/gic-v3: Switch to PMR masking before calling IRQ handler")
... since the underlying issue is that gic_handle_irq() unmasks DAIF.I and permits unintended nesting, even if that doesn't trigger a BUG() at that point.
Otherwise, this makes sense to me:
Acked-by: Mark Rutland mark.rutland@arm.com
Mark.
v2:
- Move the check right after the read of ICC_IAR1_EL1 suggested by Marc.
drivers/irqchip/irq-gic-v3.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index 94b89258d045..37a23aa6de37 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -648,6 +648,10 @@ static asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs irqnr = gic_read_iar();
- /* Check for special IDs first */
- if ((irqnr >= 1020 && irqnr <= 1023))
return;- if (gic_supports_nmi() && unlikely(gic_read_rpr() == GICD_INT_NMI_PRI)) { gic_handle_nmi(irqnr, regs);
@@ -659,10 +663,6 @@ static asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs gic_arch_enable_irqs(); }
- /* Check for special IDs first */
- if ((irqnr >= 1020 && irqnr <= 1023))
return;- if (static_branch_likely(&supports_deactivate_key)) gic_write_eoir(irqnr); else
-- 2.17.1
On Fri, 23 Apr 2021 11:50:51 +0100, Mark Rutland mark.rutland@arm.com wrote:
[...]
Fixes: 17ce302f3117 ("arm64: Fix interrupt tracing in the presence of NMIs") Signed-off-by: He Ying heying24@huawei.com
I'm reckon the fixes tag should probably be either:
Fixes: f32c926651dcd168 ("irqchip/gic-v3: Handle pseudo-NMIs")
... or:
Fixes: 3f1f3234bc2db1c1 (" irqchip/gic-v3: Switch to PMR masking before calling IRQ handler")
... since the underlying issue is that gic_handle_irq() unmasks DAIF.I and permits unintended nesting, even if that doesn't trigger a BUG() at that point.
I used the latter (see 161917211934.29796.1841651233234902273.tip-bot2@tip-bot2).
Otherwise, this makes sense to me:
Acked-by: Mark Rutland mark.rutland@arm.com
I'll update the commit to reflect this.
Thanks.
M.
The following commit has been merged into the irq/irqchip-next branch of irqchip:
Commit-ID: a97709f563a078e259bf0861cd259aa60332890a Gitweb: https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms/a97709f563... Author: He Ying heying24@huawei.com AuthorDate: Fri, 23 Apr 2021 04:35:16 -04:00 Committer: Marc Zyngier maz@kernel.org CommitterDate: Fri, 23 Apr 2021 13:19:08 +01:00
irqchip/gic-v3: Do not enable irqs when handling spurious interrups
We triggered the following error while running our 4.19 kernel with the pseudo-NMI patches backported to it:
[ 14.816231] ------------[ cut here ]------------ [ 14.816231] kernel BUG at irq.c:99! [ 14.816232] Internal error: Oops - BUG: 0 [#1] SMP [ 14.816232] Process swapper/0 (pid: 0, stack limit = 0x(____ptrval____)) [ 14.816233] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G O 4.19.95.aarch64 #14 [ 14.816233] Hardware name: evb (DT) [ 14.816234] pstate: 80400085 (Nzcv daIf +PAN -UAO) [ 14.816234] pc : asm_nmi_enter+0x94/0x98 [ 14.816235] lr : asm_nmi_enter+0x18/0x98 [ 14.816235] sp : ffff000008003c50 [ 14.816235] pmr_save: 00000070 [ 14.816237] x29: ffff000008003c50 x28: ffff0000095f56c0 [ 14.816238] x27: 0000000000000000 x26: ffff000008004000 [ 14.816239] x25: 00000000015e0000 x24: ffff8008fb916000 [ 14.816240] x23: 0000000020400005 x22: ffff0000080817cc [ 14.816241] x21: ffff000008003da0 x20: 0000000000000060 [ 14.816242] x19: 00000000000003ff x18: ffffffffffffffff [ 14.816243] x17: 0000000000000008 x16: 003d090000000000 [ 14.816244] x15: ffff0000095ea6c8 x14: ffff8008fff5ab40 [ 14.816244] x13: ffff8008fff58b9d x12: 0000000000000000 [ 14.816245] x11: ffff000008c8a200 x10: 000000008e31fca5 [ 14.816246] x9 : ffff000008c8a208 x8 : 000000000000000f [ 14.816247] x7 : 0000000000000004 x6 : ffff8008fff58b9e [ 14.816248] x5 : 0000000000000000 x4 : 0000000080000000 [ 14.816249] x3 : 0000000000000000 x2 : 0000000080000000 [ 14.816250] x1 : 0000000000120000 x0 : ffff0000095f56c0 [ 14.816251] Call trace: [ 14.816251] asm_nmi_enter+0x94/0x98 [ 14.816251] el1_irq+0x8c/0x180 (IRQ C) [ 14.816252] gic_handle_irq+0xbc/0x2e4 [ 14.816252] el1_irq+0xcc/0x180 (IRQ B) [ 14.816253] arch_timer_handler_virt+0x38/0x58 [ 14.816253] handle_percpu_devid_irq+0x90/0x240 [ 14.816253] generic_handle_irq+0x34/0x50 [ 14.816254] __handle_domain_irq+0x68/0xc0 [ 14.816254] gic_handle_irq+0xf8/0x2e4 [ 14.816255] el1_irq+0xcc/0x180 (IRQ A) [ 14.816255] arch_cpu_idle+0x34/0x1c8 [ 14.816255] default_idle_call+0x24/0x44 [ 14.816256] do_idle+0x1d0/0x2c8 [ 14.816256] cpu_startup_entry+0x28/0x30 [ 14.816256] rest_init+0xb8/0xc8 [ 14.816257] start_kernel+0x4c8/0x4f4 [ 14.816257] Code: 940587f1 d5384100 b9401001 36a7fd01 (d4210000) [ 14.816258] Modules linked in: start_dp(O) smeth(O) [ 15.103092] ---[ end trace 701753956cb14aa8 ]--- [ 15.103093] Kernel panic - not syncing: Fatal exception in interrupt [ 15.103099] SMP: stopping secondary CPUs [ 15.103100] Kernel Offset: disabled [ 15.103100] CPU features: 0x36,a2400218 [ 15.103100] Memory Limit: none
which is cause by a 'BUG_ON(in_nmi())' in nmi_enter().
From the call trace, we can find three interrupts (noted A, B, C above):
interrupt (A) is preempted by (B), which is further interrupted by (C).
Subsequent investigations show that (B) results in nmi_enter() being called, but that it actually is a spurious interrupt. Furthermore, interrupts are reenabled in the context of (B), and (C) fires with NMI priority. We end-up with a nested NMI situation, something we definitely do not want to (and cannot) handle.
The bug here is that spurious interrupts should never result in any state change, and we should just return to the interrupted context. Moving the handling of spurious interrupts as early as possible in the GICv3 handler fixes this issue.
Fixes: 3f1f3234bc2d ("irqchip/gic-v3: Switch to PMR masking before calling IRQ handler") Acked-by: Mark Rutland mark.rutland@arm.com Signed-off-by: He Ying heying24@huawei.com [maz: rewrote commit message, corrected Fixes: tag] Signed-off-by: Marc Zyngier maz@kernel.org Link: https://lore.kernel.org/r/20210423083516.170111-1-heying24@huawei.com Cc: stable@vger.kernel.org --- drivers/irqchip/irq-gic-v3.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index eb0ee35..0040402 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -648,6 +648,10 @@ static asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs
irqnr = gic_read_iar();
+ /* Check for special IDs first */ + if ((irqnr >= 1020 && irqnr <= 1023)) + return; + if (gic_supports_nmi() && unlikely(gic_read_rpr() == GICD_INT_NMI_PRI)) { gic_handle_nmi(irqnr, regs); @@ -659,10 +663,6 @@ static asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs gic_arch_enable_irqs(); }
- /* Check for special IDs first */ - if ((irqnr >= 1020 && irqnr <= 1023)) - return; - if (static_branch_likely(&supports_deactivate_key)) gic_write_eoir(irqnr); else
linux-stable-mirror@lists.linaro.org
-
He Ying -
irqchip-bot for He Ying -
Marc Zyngier -
Mark Rutland