From: Hauke Mehrtens Date: Mon, 9 Oct 2023 00:06:55 +0000 (+0200) Subject: lantiq: Fix an sleeping function called from invalid context X-Git-Url: http://git.openwrt.org/?p=openwrt%2Fstaging%2Fstintel.git;a=commitdiff_plain;h=66f6c20e45aa0eb2649d1e0552eab9e138e38601 lantiq: Fix an sleeping function called from invalid context The ifx_pcie_bus_enum_hack() function is called in ifx_pcie_read_config() while holding the ifx_pcie_lock spinlock. The ifx_pcie_bus_enum_hack() function calls pci_get_slot() which could sleep. Add a new function for pci_get_slot() which does not use a semaphore, the mutex should be sufficient. This fixes the sleep in atomic context which could cause a hang of the system. This fixes the following warning seen with CONFIG_KERNEL_DEBUG_ATOMIC_SLEEP=y. [ 12.264300] pci_bus 0000:00: No busn resource found for root bus, will use [bus 00-ff] [ 12.272226] BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1487 [ 12.280684] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 9, name: kworker/u4:0 [ 12.288781] CPU: 0 PID: 9 Comm: kworker/u4:0 Not tainted 5.15.134 #0 [ 12.295135] Workqueue: events_unbound deferred_probe_work_func [ 12.300964] Stack : 80e70000 8008ac80 00000000 00000004 807c776c 8145b9ec 81424c00 800520ec [ 12.309316] 808a0000 8145ba2b 8145b844 8145b838 80414178 00000001 8145b9f8 81439ea0 [ 12.317674] 00000000 00000000 807c776c 8145b838 ffffefff 00000000 00000000 ffffffea [ 12.326030] 00000081 8145b844 00000081 808a6f50 807c776c 00000000 00000000 80910000 [ 12.334391] 00111bef 00000000 00000001 00000000 00000018 00000030 00000000 80e40000 [ 12.342741] ... [ 12.345177] Call Trace: [ 12.347613] [<8000c1d0>] show_stack+0x28/0xf0 [ 12.351974] [<8038ba1c>] dump_stack_lvl+0x60/0x80 [ 12.356667] [<8005eefc>] ___might_sleep+0x124/0x138 [ 12.361547] [<806daf30>] down_read+0x24/0x88 [ 12.365807] [<803cdd20>] pci_get_slot+0x2c/0xc0 [ 12.370333] [<806d56ac>] ifx_pcie_read_config+0x164/0x330 [ 12.375735] [<803be610>] pci_bus_read_config_dword+0x6c/0xd0 [ 12.381399] [<803c20cc>] pci_bus_generic_read_dev_vendor_id+0x3c/0x1a8 [ 12.387915] [<803c27ec>] pci_scan_single_device+0x88/0x154 [ 12.393404] [<803c2928>] pci_scan_slot+0x70/0x134 [ 12.398099] [<803c3bf0>] pci_scan_child_bus_extend+0x5c/0x320 [ 12.403849] [<803c4178>] pci_scan_root_bus_bridge+0xd0/0xec [ 12.409414] [<806d45a8>] pcibios_scanbus+0xe4/0x21c [ 12.414293] [<806d4908>] register_pci_controller+0xb8/0x11c [ 12.419858] [<806d5f9c>] ifx_pcie_bios_probe+0x724/0x940 [ 12.425174] [<80417574>] platform_probe+0x38/0x90 [ 12.429868] [<80414d68>] really_probe.part.0+0xac/0x354 [ 12.435103] [<80415298>] driver_probe_device+0x4c/0x154 [ 12.440313] [<80415904>] __device_attach_driver+0xd0/0x15c [ 12.445802] [<804129d8>] bus_for_each_drv+0x70/0xb0 [ 12.450676] [<80415610>] __device_attach+0xdc/0x194 [ 12.455545] [<80413ca8>] bus_probe_device+0x9c/0xb8 [ 12.460419] [<8041420c>] deferred_probe_work_func+0x94/0xd4 [ 12.465995] [<8004fcb4>] process_one_work+0x27c/0x4c8 [ 12.471044] [<80050710>] worker_thread+0x34c/0x5f8 [ 12.475825] [<800587a8>] kthread+0x168/0x18c [ 12.480090] [<80006ef8>] ret_from_kernel_thread+0x14/0x1c Signed-off-by: Hauke Mehrtens --- diff --git a/target/linux/lantiq/patches-5.15/0001-MIPS-lantiq-add-pcie-driver.patch b/target/linux/lantiq/patches-5.15/0001-MIPS-lantiq-add-pcie-driver.patch index 9cd3b08b8e..b0995cbccf 100644 --- a/target/linux/lantiq/patches-5.15/0001-MIPS-lantiq-add-pcie-driver.patch +++ b/target/linux/lantiq/patches-5.15/0001-MIPS-lantiq-add-pcie-driver.patch @@ -1470,7 +1470,7 @@ Signed-off-by: John Crispin + --- /dev/null +++ b/arch/mips/pci/ifxmips_pcie_ar10.h -@@ -0,0 +1,290 @@ +@@ -0,0 +1,305 @@ +/**************************************************************************** + Copyright (c) 2010 + Lantiq Deutschland GmbH @@ -1722,6 +1722,21 @@ Signed-off-by: John Crispin + return tbus_number; +} + ++static struct pci_dev *ifx_pci_get_slot(struct pci_bus *bus, unsigned int devfn) ++{ ++ struct pci_dev *dev; ++ ++ list_for_each_entry(dev, &bus->devices, bus_list) { ++ if (dev->devfn == devfn) ++ goto out; ++ } ++ ++ dev = NULL; ++ out: ++ pci_dev_get(dev); ++ return dev; ++} ++ +static inline u32 +ifx_pcie_bus_enum_hack(struct pci_bus *bus, u32 devfn, int where, u32 value, int pcie_port, int read) +{ @@ -1729,7 +1744,7 @@ Signed-off-by: John Crispin + u32 tvalue = value; + + /* Sanity check */ -+ pdev = pci_get_slot(bus, devfn); ++ pdev = ifx_pci_get_slot(bus, devfn); + if (pdev == NULL) { + return tvalue; + } @@ -3860,7 +3875,7 @@ Signed-off-by: John Crispin + --- /dev/null +++ b/arch/mips/pci/ifxmips_pcie_vr9.h -@@ -0,0 +1,269 @@ +@@ -0,0 +1,284 @@ +/**************************************************************************** + Copyright (c) 2010 + Lantiq Deutschland GmbH @@ -4094,6 +4109,21 @@ Signed-off-by: John Crispin + return tbus_number; +} + ++static inline struct pci_dev *ifx_pci_get_slot(struct pci_bus *bus, unsigned int devfn) ++{ ++ struct pci_dev *dev; ++ ++ list_for_each_entry(dev, &bus->devices, bus_list) { ++ if (dev->devfn == devfn) ++ goto out; ++ } ++ ++ dev = NULL; ++ out: ++ pci_dev_get(dev); ++ return dev; ++} ++ +static inline u32 +ifx_pcie_bus_enum_hack(struct pci_bus *bus, u32 devfn, int where, u32 value, int pcie_port, int read) +{ @@ -4101,7 +4131,7 @@ Signed-off-by: John Crispin + u32 tvalue = value; + + /* Sanity check */ -+ pdev = pci_get_slot(bus, devfn); ++ pdev = ifx_pci_get_slot(bus, devfn); + if (pdev == NULL) { + return tvalue; + } @@ -4165,7 +4195,7 @@ Signed-off-by: John Crispin +EXPORT_SYMBOL(pcibios_1st_host_bus_nr); --- /dev/null +++ b/arch/mips/pci/pcie-lantiq.h -@@ -0,0 +1,1301 @@ +@@ -0,0 +1,1316 @@ +/****************************************************************************** +** +** FILE NAME : ifxmips_pcie_reg.h @@ -5431,6 +5461,21 @@ Signed-off-by: John Crispin + return tbus_number; +} + ++static struct pci_dev *ifx_pci_get_slot(struct pci_bus *bus, unsigned int devfn) ++{ ++ struct pci_dev *dev; ++ ++ list_for_each_entry(dev, &bus->devices, bus_list) { ++ if (dev->devfn == devfn) ++ goto out; ++ } ++ ++ dev = NULL; ++ out: ++ pci_dev_get(dev); ++ return dev; ++} ++ +static inline u32 +ifx_pcie_bus_enum_hack(struct pci_bus *bus, u32 devfn, int where, u32 value, int pcie_port, int read) +{ @@ -5438,7 +5483,7 @@ Signed-off-by: John Crispin + u32 tvalue = value; + + /* Sanity check */ -+ pdev = pci_get_slot(bus, devfn); ++ pdev = ifx_pci_get_slot(bus, devfn); + if (pdev == NULL) { + return tvalue; + }