From 547aefc4db877e65245c3d95fcce703701bf3a0c Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Tue, 5 Jul 2016 14:26:00 +0100 Subject: [PATCH] irqchip/mips-gic: Match IPI IRQ domain by bus token only Commit fbde2d7d8290 ("MIPS: Add generic SMP IPI support") introduced code which calls irq_find_matching_host with a NULL node parameter in order to discover IPI IRQ domains which are not associated with the DT root node's interrupt parent. This suggests that implementations of IPI IRQ domains should effectively ignore the node parameter if it is NULL and search purely based upon the bus token. Commit 2af70a962070 ("irqchip/mips-gic: Add a IPI hierarchy domain") did not do this when implementing the GIC IPI IRQ domain, and on MIPS Boston boards this leads to no IPI domain being discovered and a NULL pointer dereference when attempting to send an IPI: CPU 0 Unable to handle kernel paging request at virtual address 0000000000000040, epc == ffffffff8016e70c, ra == ffffffff8010ff5c Oops[#1]: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.7.0-rc6-00223-gad0d1b6 #945 task: a8000000ff066fc0 ti: a8000000ff068000 task.ti: a8000000ff068000 $ 0 : 0000000000000000 0000000000000001 ffffffff80730000 0000000000000003 $ 4 : 0000000000000000 ffffffff8057e5b0 a800000001e3ee00 0000000000000000 $ 8 : 0000000000000000 0000000000000023 0000000000000001 0000000000000001 $12 : 0000000000000000 ffffffff803323d0 0000000000000000 0000000000000000 $16 : 0000000000000000 0000000000000000 0000000000000001 ffffffff801108fc $20 : 0000000000000000 ffffffff8057e5b0 0000000000000001 0000000000000000 $24 : 0000000000000000 ffffffff8012de28 $28 : a8000000ff068000 a8000000ff06fbc0 0000000000000000 ffffffff8010ff5c Hi : ffffffff8014c174 Lo : a800000001e1e140 epc : ffffffff8016e70c __ipi_send_mask+0x24/0x11c ra : ffffffff8010ff5c mips_smp_send_ipi_mask+0x68/0x178 Status: 140084e2 KX SX UX KERNEL EXL Cause : 00800008 (ExcCode 02) BadVA : 0000000000000040 PrId : 0001a920 (MIPS I6400) Process swapper/0 (pid: 1, threadinfo=a8000000ff068000, task=a8000000ff066fc0, tls=0000000000000000) Stack : 0000000000000000 0000000000000000 0000000000000001 ffffffff801108fc 0000000000000000 ffffffff8057e5b0 0000000000000001 ffffffff8010ff5c 0000000000000001 0000000000000020 0000000000000000 0000000000000000 0000000000000000 ffffffff801108fc 0000000000000000 0000000000000001 0000000000000001 0000000000000000 0000000000000000 ffffffff801865e8 a8000000ff0c7500 a8000000ff06fc90 0000000000000001 0000000000000002 ffffffff801108fc ffffffff801868b8 0000000000000000 ffffffff801108fc 0000000000000000 0000000000000003 ffffffff8068c700 0000000000000001 ffffffff80730000 0000000000000001 a8000000ff00a290 ffffffff80110c50 0000000000000003 a800000001e48308 0000000000000003 0000000000000008 ... Call Trace: [] __ipi_send_mask+0x24/0x11c [] mips_smp_send_ipi_mask+0x68/0x178 [] generic_exec_single+0x150/0x170 [] smp_call_function_single+0x108/0x160 [] cps_boot_secondary+0x328/0x394 [] __cpu_up+0x38/0x90 [] bringup_cpu+0x24/0xac [] cpuhp_up_callbacks+0x58/0xdc [] cpu_up+0x118/0x18c [] smp_init+0xbc/0xe8 [] kernel_init_freeable+0xa0/0x228 [] kernel_init+0x10/0xf0 [] ret_from_kernel_thread+0x14/0x1c Fix this by allowing the GIC IPI IRQ domain to match purely based upon the bus token if the node provided is NULL. Fixes: 2af70a962070 ("irqchip/mips-gic: Add a IPI hierarchy domain") Signed-off-by: Paul Burton Cc: linux-mips@linux-mips.org Cc: Jason Cooper Cc: Qais Yousef Cc: Ralf Baechle Cc: Marc Zyngier Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20160705132600.27730-2-paul.burton@imgtec.com Signed-off-by: Thomas Gleixner --- drivers/irqchip/irq-mips-gic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c index 69b1b8275e4f..70ed1d0151b8 100644 --- a/drivers/irqchip/irq-mips-gic.c +++ b/drivers/irqchip/irq-mips-gic.c @@ -959,7 +959,7 @@ int gic_ipi_domain_match(struct irq_domain *d, struct device_node *node, switch (bus_token) { case DOMAIN_BUS_IPI: is_ipi = d->bus_token == bus_token; - return to_of_node(d->fwnode) == node && is_ipi; + return (!node || to_of_node(d->fwnode) == node) && is_ipi; break; default: return 0; -- GitLab