Re: irqchip/irq-gic: BAD_MADT_GICC_ENTRY may fail when booting with ACPI 5.1

From: Lorenzo Pieralisi
Date: Tue May 23 2017 - 13:06:21 EST

[+Al]

On Tue, May 23, 2017 at 05:40:28PM +0100, Julien Grall wrote:
> Hi all,
>
> I am currently looking at adding support of ACPI 5.1 in Xen.
> When trying to boot DOM00 I get a panic in Linux (for the full
> log see [1]):
>
> (XEN) DOM0: [ 0.000000] No valid GICC entries exist
>
> The error message is coming from gic_v2_acpi_init.
> Digging down in the code, it is failing because of
> BAD_MADT_GICC_ENTRY is returning false in
> gic_acpi_parse_madt_cpu:
>
> /* Macros for consistency checks of the GICC subtable of MADT */
> #define ACPI_MADT_GICC_LENGTH \
> (acpi_gbl_FADT.header.revision < 6 ? 76 : 80)
>
> #define BAD_MADT_GICC_ENTRY(entry, end) \
> (!(entry) || (unsigned long)(entry) + sizeof(*(entry)) > (end) || \
> (entry)->header.length != ACPI_MADT_GICC_LENGTH)
>
> The 'end' parameter corresponds to the end of the MADT table.
> In the case of ACPI 5.1, the size of GICC is smaller compare
> to 6.0+ (76 vs 80 bytes) but the parameter 'entry' is type
> of acpi_madt_generic_interrupt (sizeof(...) = 80).

#define BAD_MADT_GICC_ENTRY(entry, end) \
(!(entry) || (entry)->header.length != ACPI_MADT_GICC_LENGTH || \
((unsigned long)(entry) + ACPI_MADT_GICC_LENGTH) > (end))

Would this solve it ?

Lorenzo

> This mean that if the GICC entry is at the end of table, the
> check will return false.
>
> Indeed the way the MADT table is generated in Xen will put
> the GICC entries at the end of the table.
>
> I haven't seen this issue on ACPI 5.1 platforms (such as Juno
> and Seattle) because the GICC entries are not at the end
> of the table.
>
> I have looked at the usage of BAD_MADT_GICC_ENTRY, it spreads
> in few places over the kernel (e.g smp, gic-v2, gic-v3).
> The structure acpi_madt_generic_interrupt is even more widespread.
>
> My current workaround is to re-order the GICC entries in the
> MADT. I am not sure what would be the correct way to fix it
> in Linux, I am seeking any advice here.
>
> Cheers,
>
> [1]
> (XEN) DOM0: [ 0.000000] Booting Linux on physical CPU 0x0
> (XEN) DOM0: [ 0.000000] Linux version 4.12.0-rc2-00049-gfde8e33d1068 (julieng@e108454-lin) (gcc version 6.1.1 20160711 (Linaro GCC 6.1-
> (XEN) DOM0: 2016.08) ) #547 SMP PREEMPT Tue May 23 17:04:43 BST 2017
> (XEN) DOM0: [ 0.000000] Boot CPU: AArch64 Processor [410fd033]
> (XEN) DOM0: [ 0.000000] Machine model: (null)
> (XEN) DOM0: [ 0.000000] earlycon: pl11 at MMIO 0x000000007ff80000 (options '')
> (XEN) DOM0: [ 0.000000] bootconsole [pl11] enabled
> (XEN) DOM0: [ 0.000000] Xen 4.9 support found
> (XEN) DOM0: [ 0.000000] efi: Getting EFI parameters from FDT:
> (XEN) DOM0: [ 0.000000] efi: EFI v2.50 by Xen
> (XEN) DOM0: [ 0.000000] efi: ACPI 2.0=0x99be00280
> (XEN) DOM0: [ 0.000000] cma: Reserved 16 MiB at 0x00000000ef000000
> (XEN) DOM0: [ 0.000000] ACPI: Early table checksum verification disabled
> (XEN) DOM0: [ 0.000000] ACPI: RSDP 0x000000099BE00280 000024 (v02 ARMLTD)
> (XEN) DOM0: [ 0.000000] ACPI: XSDT 0x000000099BE00218 000064 (v01 ARMLTD ARM-JUNO 20140727 01000013)
> (XEN) DOM0: [ 0.000000] ACPI: FACP 0x000000099BE00000 00010C (v05 ARMLTD ARM-JUNO 20140727 ARM 00000099)
> (XEN) DOM0: [ 0.000000] ACPI: DSDT 0x00000000F8980000 0006C9 (v01 ARMLTD ARM-JUNO 20140727 INTL 20160527)
> (XEN) DOM0: [ 0.000000] ACPI: DBG2 0x00000000F89E0000 00005A (v00 ARMLTD ARM-JUNO 20140727 ARM 00000099)
> (XEN) DOM0: [ 0.000000] ACPI: GTDT 0x00000000F89C0000 000098 (v02 ARMLTD ARM-JUNO 20140727 ARM 00000099)
> (XEN) DOM0: [ 0.000000] ACPI: APIC 0x000000099BE00110 0000DC (v03 ARMLTD ARM-JUNO 20140727 ARM 00000099)
> (XEN) DOM0: [ 0.000000] ACPI: SPCR 0x00000000F89A0000 000050 (v02 ARMLTD ARM-JUNO 20140727 ARM 00000099)
> (XEN) DOM0: [ 0.000000] ACPI: SSDT 0x00000000F8990000 000306 (v01 ARMLTD ARM-JUNO 20140727 INTL 20160527)
> (XEN) DOM0: [ 0.000000] ACPI: MCFG 0x00000000F8970000 00003C (v01 ARMLTD ARM-JUNO 20140727 ARM 00000099)
> (XEN) DOM0: [ 0.000000] ACPI: STAO 0x000000099BE001F0 000025 (v01 ARMLTD ARM-JUNO 20140727 ARM 00000099)
> (XEN) DOM0: [ 0.000000] ACPI: SPCR: console: pl011,mmio,0x7ff80000,115200
> (XEN) DOM0: [ 0.000000] psci: probing for conduit method from ACPI.
> (XEN) DOM0: [ 0.000000] psci: PSCIv0.2 detected in firmware.
> (XEN) DOM0: [ 0.000000] psci: Using standard PSCI v0.2 function IDs
> (XEN) DOM0: [ 0.000000] psci: Trusted OS migration not required
> (XEN) DOM0: [ 0.000000] percpu: Embedded 24 pages/cpu @ffff800907fd7000 s59672 r8192 d30440 u98304
> (XEN) DOM0: [ 0.000000] Detected VIPT I-cache on CPU0
> (XEN) DOM0: [ 0.000000] CPU features: enabling workaround for ARM erratum 845719
> (XEN) DOM0: [ 0.000000] Built 1 zonelists in Zone order, mobility grouping on. Total pages: 774301
> (XEN) DOM0: [ 0.000000] Kernel command line: root=/dev/mapper/juno2--julieng--vg-root ro loglvlinfo=all earlycon=pl011,0x7ff80000 conso
> (XEN) DOM0: le=hvc0
> (XEN) DOM0: [ 0.000000] PID hash table entries: 4096 (order: 3, 32768 bytes)
> (XEN) DOM0: [ 0.000000] Dentry cache hash table entries: 524288 (order: 10, 4194304 bytes)
> (XEN) DOM0: [ 0.000000] Inode-cache hash table entries: 262144 (order: 9, 2097152 bytes)
> (XEN) DOM0: [ 0.000000] software IO TLB [mem 0xeafff000-0xeefff000] (64MB) mapped at [ffff80006afff000-ffff80006effefff]
> (XEN) DOM0: [ 0.000000] Memory: 2901652K/3146372K available (9212K kernel code, 1016K rwdata, 3844K rodata, 1088K init, 305K bss, 22833
> (XEN) DOM0: 6K reserved, 16384K cma-reserved)
> (XEN) DOM0: [ 0.000000] Virtual kernel memory layout:
> (XEN) DOM0: [ 0.000000] modules : 0xffff000000000000 - 0xffff000008000000 ( 128 MB)
> (XEN) DOM0: [ 0.000000] vmalloc : 0xffff000008000000 - 0xffff7dffbfff0000 (129022 GB)
> (XEN) DOM0: [ 0.000000] .text : 0xffff000008080000 - 0xffff000008980000 ( 9216 KB)
> (XEN) DOM0: [ 0.000000] .rodata : 0xffff000008980000 - 0xffff000008d50000 ( 3904 KB)
> (XEN) DOM0: [ 0.000000] .init : 0xffff000008d50000 - 0xffff000008e60000 ( 1088 KB)
> (XEN) DOM0: [ 0.000000] .data : 0xffff000008e60000 - 0xffff000008f5e200 ( 1017 KB)
> (XEN) DOM0: [ 0.000000] .bss : 0xffff000008f5e200 - 0xffff000008faa95c ( 306 KB)
> (XEN) DOM0: [ 0.000000] fixed : 0xffff7dfffe7fd000 - 0xffff7dfffec00000 ( 4108 KB)
> (XEN) DOM0: [ 0.000000] PCI I/O : 0xffff7dfffee00000 - 0xffff7dffffe00000 ( 16 MB)
> (XEN) DOM0: [ 0.000000] vmemmap : 0xffff7e0000000000 - 0xffff800000000000 ( 2048 GB maximum)
> (XEN) DOM0: [ 0.000000] 0xffff7e0000000000 - 0xffff7e00246f8040 ( 582 MB actual)
> (XEN) DOM0: [ 0.000000] memory : 0xffff800000000000 - 0xffff80091be01000 ( 37310 MB)
> (XEN) DOM0: [ 0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
> (XEN) DOM0: [ 0.000000] Preemptible hierarchical RCU implementation.
> (XEN) DOM0: [ 0.000000] RCU restricting CPUs from NR_CPUS=64 to nr_cpu_ids=1.
> (XEN) DOM0: [ 0.000000] RCU: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=1
> (XEN) DOM0: [ 0.000000] NR_IRQS:64 nr_irqs:64 0
> (XEN) DOM0: [ 0.000000] No valid GICC entries exist
> (XEN) DOM0: [ 0.000000] Kernel panic - not syncing: No interrupt controller found.
> (XEN) DOM0: [ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.12.0-rc2-00049-gfde8e33d1068 #547
> (XEN) DOM0: [ 0.000000] Hardware name: (null) (DT)
> (XEN) DOM0: [ 0.000000] Call trace:
> (XEN) DOM0: [ 0.000000] [<ffff000008088608>] dump_backtrace+0x0/0x228
> (XEN) DOM0: [ 0.000000] [<ffff0000080888f4>] show_stack+0x14/0x20
> (XEN) DOM0: [ 0.000000] [<ffff000008409360>] dump_stack+0x98/0xb8
> (XEN) DOM0: [ 0.000000] [<ffff0000081698a0>] panic+0x114/0x284
> (XEN) DOM0: [ 0.000000] [<ffff000008d524a8>] init_IRQ+0x24/0x2c
> (XEN) DOM0: [ 0.000000] [<ffff000008d509f8>] start_kernel+0x230/0x390
> (XEN) DOM0: [ 0.000000] [<ffff000008d501e0>] __primary_switched+0x64/0x6c
> (XEN) DOM0: [ 0.000000] ---[ end Kernel panic - not syncing: No interrupt controller found.
>
> Cheers,
>
> --
> Julien Grall