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2026-03-04powerpc/eeh: fix recursive pci_lock_rescan_remove locking in EEH event handlingNarayana Murty N
[ Upstream commit 815a8d2feb5615ae7f0b5befd206af0b0160614c ] The recent commit 1010b4c012b0 ("powerpc/eeh: Make EEH driver device hotplug safe") restructured the EEH driver to improve synchronization with the PCI hotplug layer. However, it inadvertently moved pci_lock_rescan_remove() outside its intended scope in eeh_handle_normal_event(), leading to broken PCI error reporting and improper EEH event triggering. Specifically, eeh_handle_normal_event() acquired pci_lock_rescan_remove() before calling eeh_pe_bus_get(), but eeh_pe_bus_get() itself attempts to acquire the same lock internally, causing nested locking and disrupting normal EEH event handling paths. This patch adds a boolean parameter do_lock to _eeh_pe_bus_get(), with two public wrappers: eeh_pe_bus_get() with locking enabled. eeh_pe_bus_get_nolock() that skips locking. Callers that already hold pci_lock_rescan_remove() now use eeh_pe_bus_get_nolock() to avoid recursive lock acquisition. Additionally, pci_lock_rescan_remove() calls are restored to the correct position—after eeh_pe_bus_get() and immediately before iterating affected PEs and devices. This ensures EEH-triggered PCI removes occur under proper bus rescan locking without recursive lock contention. The eeh_pe_loc_get() function has been split into two functions: eeh_pe_loc_get(struct eeh_pe *pe) which retrieves the loc for given PE. eeh_pe_loc_get_bus(struct pci_bus *bus) which retrieves the location code for given bus. This resolves lockdep warnings such as: <snip> [ 84.964298] [ T928] ============================================ [ 84.964304] [ T928] WARNING: possible recursive locking detected [ 84.964311] [ T928] 6.18.0-rc3 #51 Not tainted [ 84.964315] [ T928] -------------------------------------------- [ 84.964320] [ T928] eehd/928 is trying to acquire lock: [ 84.964324] [ T928] c000000003b29d58 (pci_rescan_remove_lock){+.+.}-{3:3}, at: pci_lock_rescan_remove+0x28/0x40 [ 84.964342] [ T928] but task is already holding lock: [ 84.964347] [ T928] c000000003b29d58 (pci_rescan_remove_lock){+.+.}-{3:3}, at: pci_lock_rescan_remove+0x28/0x40 [ 84.964357] [ T928] other info that might help us debug this: [ 84.964363] [ T928] Possible unsafe locking scenario: [ 84.964367] [ T928] CPU0 [ 84.964370] [ T928] ---- [ 84.964373] [ T928] lock(pci_rescan_remove_lock); [ 84.964378] [ T928] lock(pci_rescan_remove_lock); [ 84.964383] [ T928] *** DEADLOCK *** [ 84.964388] [ T928] May be due to missing lock nesting notation [ 84.964393] [ T928] 1 lock held by eehd/928: [ 84.964397] [ T928] #0: c000000003b29d58 (pci_rescan_remove_lock){+.+.}-{3:3}, at: pci_lock_rescan_remove+0x28/0x40 [ 84.964408] [ T928] stack backtrace: [ 84.964414] [ T928] CPU: 2 UID: 0 PID: 928 Comm: eehd Not tainted 6.18.0-rc3 #51 VOLUNTARY [ 84.964417] [ T928] Hardware name: IBM,9080-HEX POWER10 (architected) 0x800200 0xf000006 of:IBM,FW1060.00 (NH1060_022) hv:phyp pSeries [ 84.964419] [ T928] Call Trace: [ 84.964420] [ T928] [c0000011a7157990] [c000000001705de4] dump_stack_lvl+0xc8/0x130 (unreliable) [ 84.964424] [ T928] [c0000011a71579d0] [c0000000002f66e0] print_deadlock_bug+0x430/0x440 [ 84.964428] [ T928] [c0000011a7157a70] [c0000000002fd0c0] __lock_acquire+0x1530/0x2d80 [ 84.964431] [ T928] [c0000011a7157ba0] [c0000000002fea54] lock_acquire+0x144/0x410 [ 84.964433] [ T928] [c0000011a7157cb0] [c0000011a7157cb0] __mutex_lock+0xf4/0x1050 [ 84.964436] [ T928] [c0000011a7157e00] [c000000000de21d8] pci_lock_rescan_remove+0x28/0x40 [ 84.964439] [ T928] [c0000011a7157e20] [c00000000004ed98] eeh_pe_bus_get+0x48/0xc0 [ 84.964442] [ T928] [c0000011a7157e50] [c000000000050434] eeh_handle_normal_event+0x64/0xa60 [ 84.964446] [ T928] [c0000011a7157f30] [c000000000051de8] eeh_event_handler+0xf8/0x190 [ 84.964450] [ T928] [c0000011a7157f90] [c0000000002747ac] kthread+0x16c/0x180 [ 84.964453] [ T928] [c0000011a7157fe0] [c00000000000ded8] start_kernel_thread+0x14/0x18 </snip> Fixes: 1010b4c012b0 ("powerpc/eeh: Make EEH driver device hotplug safe") Signed-off-by: Narayana Murty N <nnmlinux@linux.ibm.com> Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com> Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com> Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> Link: https://patch.msgid.link/20251210142559.8874-1-nnmlinux@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-19powerpc/64s/slb: Fix SLB multihit issue during SLB preloadDonet Tom
[ Upstream commit 00312419f0863964625d6dcda8183f96849412c6 ] On systems using the hash MMU, there is a software SLB preload cache that mirrors the entries loaded into the hardware SLB buffer. This preload cache is subject to periodic eviction — typically after every 256 context switches — to remove old entry. To optimize performance, the kernel skips switch_mmu_context() in switch_mm_irqs_off() when the prev and next mm_struct are the same. However, on hash MMU systems, this can lead to inconsistencies between the hardware SLB and the software preload cache. If an SLB entry for a process is evicted from the software cache on one CPU, and the same process later runs on another CPU without executing switch_mmu_context(), the hardware SLB may retain stale entries. If the kernel then attempts to reload that entry, it can trigger an SLB multi-hit error. The following timeline shows how stale SLB entries are created and can cause a multi-hit error when a process moves between CPUs without a MMU context switch. CPU 0 CPU 1 ----- ----- Process P exec swapper/1 load_elf_binary begin_new_exc activate_mm switch_mm_irqs_off switch_mmu_context switch_slb /* * This invalidates all * the entries in the HW * and setup the new HW * SLB entries as per the * preload cache. */ context_switch sched_migrate_task migrates process P to cpu-1 Process swapper/0 context switch (to process P) (uses mm_struct of Process P) switch_mm_irqs_off() switch_slb load_slb++ /* * load_slb becomes 0 here * and we evict an entry from * the preload cache with * preload_age(). We still * keep HW SLB and preload * cache in sync, that is * because all HW SLB entries * anyways gets evicted in * switch_slb during SLBIA. * We then only add those * entries back in HW SLB, * which are currently * present in preload_cache * (after eviction). */ load_elf_binary continues... setup_new_exec() slb_setup_new_exec() sched_switch event sched_migrate_task migrates process P to cpu-0 context_switch from swapper/0 to Process P switch_mm_irqs_off() /* * Since both prev and next mm struct are same we don't call * switch_mmu_context(). This will cause the HW SLB and SW preload * cache to go out of sync in preload_new_slb_context. Because there * was an SLB entry which was evicted from both HW and preload cache * on cpu-1. Now later in preload_new_slb_context(), when we will try * to add the same preload entry again, we will add this to the SW * preload cache and then will add it to the HW SLB. Since on cpu-0 * this entry was never invalidated, hence adding this entry to the HW * SLB will cause a SLB multi-hit error. */ load_elf_binary continues... START_THREAD start_thread preload_new_slb_context /* * This tries to add a new EA to preload cache which was earlier * evicted from both cpu-1 HW SLB and preload cache. This caused the * HW SLB of cpu-0 to go out of sync with the SW preload cache. The * reason for this was, that when we context switched back on CPU-0, * we should have ideally called switch_mmu_context() which will * bring the HW SLB entries on CPU-0 in sync with SW preload cache * entries by setting up the mmu context properly. But we didn't do * that since the prev mm_struct running on cpu-0 was same as the * next mm_struct (which is true for swapper / kernel threads). So * now when we try to add this new entry into the HW SLB of cpu-0, * we hit a SLB multi-hit error. */ WARNING: CPU: 0 PID: 1810970 at arch/powerpc/mm/book3s64/slb.c:62 assert_slb_presence+0x2c/0x50(48 results) 02:47:29 [20157/42149] Modules linked in: CPU: 0 UID: 0 PID: 1810970 Comm: dd Not tainted 6.16.0-rc3-dirty #12 VOLUNTARY Hardware name: IBM pSeries (emulated by qemu) POWER8 (architected) 0x4d0200 0xf000004 of:SLOF,HEAD hv:linux,kvm pSeries NIP: c00000000015426c LR: c0000000001543b4 CTR: 0000000000000000 REGS: c0000000497c77e0 TRAP: 0700 Not tainted (6.16.0-rc3-dirty) MSR: 8000000002823033 <SF,VEC,VSX,FP,ME,IR,DR,RI,LE> CR: 28888482 XER: 00000000 CFAR: c0000000001543b0 IRQMASK: 3 <...> NIP [c00000000015426c] assert_slb_presence+0x2c/0x50 LR [c0000000001543b4] slb_insert_entry+0x124/0x390 Call Trace: 0x7fffceb5ffff (unreliable) preload_new_slb_context+0x100/0x1a0 start_thread+0x26c/0x420 load_elf_binary+0x1b04/0x1c40 bprm_execve+0x358/0x680 do_execveat_common+0x1f8/0x240 sys_execve+0x58/0x70 system_call_exception+0x114/0x300 system_call_common+0x160/0x2c4 >>From the above analysis, during early exec the hardware SLB is cleared, and entries from the software preload cache are reloaded into hardware by switch_slb. However, preload_new_slb_context and slb_setup_new_exec also attempt to load some of the same entries, which can trigger a multi-hit. In most cases, these additional preloads simply hit existing entries and add nothing new. Removing these functions avoids redundant preloads and eliminates the multi-hit issue. This patch removes these two functions. We tested process switching performance using the context_switch benchmark on POWER9/hash, and observed no regression. Without this patch: 129041 ops/sec With this patch: 129341 ops/sec We also measured SLB faults during boot, and the counts are essentially the same with and without this patch. SLB faults without this patch: 19727 SLB faults with this patch: 19786 Fixes: 5434ae74629a ("powerpc/64s/hash: Add a SLB preload cache") cc: stable@vger.kernel.org Suggested-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Donet Tom <donettom@linux.ibm.com> Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> Link: https://patch.msgid.link/0ac694ae683494fe8cadbd911a1a5018d5d3c541.1761834163.git.ritesh.list@gmail.com [ Adjust context ] Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-12-07powerpc/eeh: Use result of error_detected() in ueventNiklas Schnelle
[ Upstream commit 704e5dd1c02371dfc7d22e1520102b197a3b628b ] Ever since uevent support was added for AER and EEH with commit 856e1eb9bdd4 ("PCI/AER: Add uevents in AER and EEH error/resume"), it reported PCI_ERS_RESULT_NONE as uevent when recovery begins. Commit 7b42d97e99d3 ("PCI/ERR: Always report current recovery status for udev") subsequently amended AER to report the actual return value of error_detected(). Make the same change to EEH to align it with AER and s390. Suggested-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/linux-pci/aIp6LiKJor9KLVpv@wunner.de/ Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Lukas Wunner <lukas@wunner.de> Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Acked-by: Mahesh Salgaonkar <mahesh@linux.ibm.com> Link: https://patch.msgid.link/20250807-add_err_uevents-v5-3-adf85b0620b0@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-09-04powerpc/kvm: Fix ifdef to remove build warningMadhavan Srinivasan
[ Upstream commit 88688a2c8ac6c8036d983ad8b34ce191c46a10aa ] When compiling for pseries or powernv defconfig with "make C=1", these warning were reported bu sparse tool in powerpc/kernel/kvm.c arch/powerpc/kernel/kvm.c:635:9: warning: switch with no cases arch/powerpc/kernel/kvm.c:646:9: warning: switch with no cases Currently #ifdef were added after the switch case which are specific for BOOKE and PPC_BOOK3S_32. These are not enabled in pseries/powernv defconfig. Fix it by moving the #ifdef before switch(){} Fixes: cbe487fac7fc0 ("KVM: PPC: Add mtsrin PV code") Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com> Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> Link: https://patch.msgid.link/20250518044107.39928-1-maddy@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-28PCI: pnv_php: Fix surprise plug detection and recoveryTimothy Pearson
[ Upstream commit a2a2a6fc2469524caa713036297c542746d148dc ] The existing PowerNV hotplug code did not handle surprise plug events correctly, leading to a complete failure of the hotplug system after device removal and a required reboot to detect new devices. This comes down to two issues: 1) When a device is surprise removed, often the bridge upstream port will cause a PE freeze on the PHB. If this freeze is not cleared, the MSI interrupts from the bridge hotplug notification logic will not be received by the kernel, stalling all plug events on all slots associated with the PE. 2) When a device is removed from a slot, regardless of surprise or programmatic removal, the associated PHB/PE ls left frozen. If this freeze is not cleared via a fundamental reset, skiboot is unable to clear the freeze and cannot retrain / rescan the slot. This also requires a reboot to clear the freeze and redetect the device in the slot. Issue the appropriate unfreeze and rescan commands on hotplug events, and don't oops on hotplug if pci_bus_to_OF_node() returns NULL. Signed-off-by: Timothy Pearson <tpearson@raptorengineering.com> [bhelgaas: tidy comments] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> Link: https://patch.msgid.link/171044224.1359864.1752615546988.JavaMail.zimbra@raptorengineeringinc.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-28powerpc/eeh: Make EEH driver device hotplug safeTimothy Pearson
[ Upstream commit 1010b4c012b0d78dfb9d3132b49aa2ef024a07a7 ] Multiple race conditions existed between the PCIe hotplug driver and the EEH driver, leading to a variety of kernel oopses of the same general nature: <pcie device unplug> <eeh driver trigger> <hotplug removal trigger> <pcie tree reconfiguration> <eeh recovery next step> <oops in EEH driver bus iteration loop> A second class of oops is also seen when the underlying bus disappears during device recovery. Refactor the EEH module to be PCI rescan and remove safe. Also clean up a few minor formatting / readability issues. Signed-off-by: Timothy Pearson <tpearson@raptorengineering.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> Link: https://patch.msgid.link/1334208367.1359861.1752615503144.JavaMail.zimbra@raptorengineeringinc.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-28powerpc/eeh: Rely on dev->link_active_reportingMaciej W. Rozycki
[ Upstream commit 1541a21305ceb10fcf3f7cbb23f3e1a00bbf1789 ] Use dev->link_active_reporting to determine whether Data Link Layer Link Active Reporting is available rather than re-retrieving the capability. Link: https://lore.kernel.org/r/alpine.DEB.2.21.2305310124100.59226@angie.orcam.me.uk Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-28powerpc/eeh: Export eeh_unfreeze_pe()Timothy Pearson
[ Upstream commit e82b34eed04b0ddcff4548b62633467235672fd3 ] The PowerNV hotplug driver needs to be able to clear any frozen PE(s) on the PHB after suprise removal of a downstream device. Export the eeh_unfreeze_pe() symbol to allow implementation of this functionality in the php_nv module. Signed-off-by: Timothy Pearson <tpearson@raptorengineering.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> Link: https://patch.msgid.link/1778535414.1359858.1752615454618.JavaMail.zimbra@raptorengineeringinc.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-27powerpc/eeh: Fix missing PE bridge reconfiguration during VFIO EEH recoveryNarayana Murty N
[ Upstream commit 33bc69cf6655cf60829a803a45275f11a74899e5 ] VFIO EEH recovery for PCI passthrough devices fails on PowerNV and pseries platforms due to missing host-side PE bridge reconfiguration. In the current implementation, eeh_pe_configure() only performs RTAS or OPAL-based bridge reconfiguration for native host devices, but skips it entirely for PEs managed through VFIO in guest passthrough scenarios. This leads to incomplete EEH recovery when a PCI error affects a passthrough device assigned to a QEMU/KVM guest. Although VFIO triggers the EEH recovery flow through VFIO_EEH_PE_ENABLE ioctl, the platform-specific bridge reconfiguration step is silently bypassed. As a result, the PE's config space is not fully restored, causing subsequent config space access failures or EEH freeze-on-access errors inside the guest. This patch fixes the issue by ensuring that eeh_pe_configure() always invokes the platform's configure_bridge() callback (e.g., pseries_eeh_phb_configure_bridge) even for VFIO-managed PEs. This ensures that RTAS or OPAL calls to reconfigure the PE bridge are correctly issued on the host side, restoring the PE's configuration space after an EEH event. This fix is essential for reliable EEH recovery in QEMU/KVM guests using VFIO PCI passthrough on PowerNV and pseries systems. Tested with: - QEMU/KVM guest using VFIO passthrough (IBM Power9,(lpar)Power11 host) - Injected EEH errors with pseries EEH errinjct tool on host, recovery verified on qemu guest. - Verified successful config space access and CAP_EXP DevCtl restoration after recovery Fixes: 212d16cdca2d ("powerpc/eeh: EEH support for VFIO PCI device") Signed-off-by: Narayana Murty N <nnmlinux@linux.ibm.com> Reviewed-by: Vaibhav Jain <vaibhav@linux.ibm.com> Reviewed-by: Ganesh Goudar <ganeshgr@linux.ibm.com> Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> Link: https://patch.msgid.link/20250508062928.146043-1-nnmlinux@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-04powerpc/prom_init: Fixup missing #size-cells on PowerBook6,7Andreas Schwab
[ Upstream commit 7e67ef889c9ab7246547db73d524459f47403a77 ] Similar to the PowerMac3,1, the PowerBook6,7 is missing the #size-cells property on the i2s node. Depends-on: commit 045b14ca5c36 ("of: WARN on deprecated #address-cells/#size-cells handling") Signed-off-by: Andreas Schwab <schwab@linux-m68k.org> Acked-by: Rob Herring (Arm) <robh@kernel.org> [maddy: added "commit" work in depends-on to avoid checkpatch error] Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> Link: https://patch.msgid.link/875xmizl6a.fsf@igel.home Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-02powerpc/rtas: Prevent Spectre v1 gadget construction in sys_rtas()Nathan Lynch
commit 0974d03eb479384466d828d65637814bee6b26d7 upstream. Smatch warns: arch/powerpc/kernel/rtas.c:1932 __do_sys_rtas() warn: potential spectre issue 'args.args' [r] (local cap) The 'nargs' and 'nret' locals come directly from a user-supplied buffer and are used as indexes into a small stack-based array and as inputs to copy_to_user() after they are subject to bounds checks. Use array_index_nospec() after the bounds checks to clamp these values for speculative execution. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reported-by: Breno Leitao <leitao@debian.org> Reviewed-by: Breno Leitao <leitao@debian.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20240530-sys_rtas-nargs-nret-v1-1-129acddd4d89@linux.ibm.com [Minor context change fixed] Signed-off-by: Cliff Liu <donghua.liu@windriver.com> Signed-off-by: He Zhe <Zhe.He@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-14powerpc/prom_init: Fixup missing powermac #size-cellsMichael Ellerman
[ Upstream commit cf89c9434af122f28a3552e6f9cc5158c33ce50a ] On some powermacs `escc` nodes are missing `#size-cells` properties, which is deprecated and now triggers a warning at boot since commit 045b14ca5c36 ("of: WARN on deprecated #address-cells/#size-cells handling"). For example: Missing '#size-cells' in /pci@f2000000/mac-io@c/escc@13000 WARNING: CPU: 0 PID: 0 at drivers/of/base.c:133 of_bus_n_size_cells+0x98/0x108 Hardware name: PowerMac3,1 7400 0xc0209 PowerMac ... Call Trace: of_bus_n_size_cells+0x98/0x108 (unreliable) of_bus_default_count_cells+0x40/0x60 __of_get_address+0xc8/0x21c __of_address_to_resource+0x5c/0x228 pmz_init_port+0x5c/0x2ec pmz_probe.isra.0+0x144/0x1e4 pmz_console_init+0x10/0x48 console_init+0xcc/0x138 start_kernel+0x5c4/0x694 As powermacs boot via prom_init it's possible to add the missing properties to the device tree during boot, avoiding the warning. Note that `escc-legacy` nodes are also missing `#size-cells` properties, but they are skipped by the macio driver, so leave them alone. Depends-on: 045b14ca5c36 ("of: WARN on deprecated #address-cells/#size-cells handling") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> Link: https://patch.msgid.link/20241126025710.591683-1-mpe@ellerman.id.au Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-10-17powerpc/mm: Fix boot warning with hugepages and CONFIG_DEBUG_VIRTUALChristophe Leroy
[ Upstream commit e7e846dc6c73fbc94ae8b4ec20d05627646416f2 ] Booting with CONFIG_DEBUG_VIRTUAL leads to following warning when passing hugepage reservation on command line: Kernel command line: hugepagesz=1g hugepages=1 hugepagesz=64m hugepages=1 hugepagesz=256m hugepages=1 noreboot HugeTLB: allocating 1 of page size 1.00 GiB failed. Only allocated 0 hugepages. ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at arch/powerpc/include/asm/io.h:948 __alloc_bootmem_huge_page+0xd4/0x284 Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 6.10.0-rc6-00396-g6b0e82791bd0-dirty #936 Hardware name: MPC8544DS e500v2 0x80210030 MPC8544 DS NIP: c1020240 LR: c10201d0 CTR: 00000000 REGS: c13fdd30 TRAP: 0700 Not tainted (6.10.0-rc6-00396-g6b0e82791bd0-dirty) MSR: 00021000 <CE,ME> CR: 44084288 XER: 20000000 GPR00: c10201d0 c13fde20 c130b560 e8000000 e8001000 00000000 00000000 c1420000 GPR08: 00000000 00028001 00000000 00000004 44084282 01066ac0 c0eb7c9c efffe149 GPR16: c0fc4228 0000005f ffffffff c0eb7d0c c0eb7cc0 c0eb7ce0 ffffffff 00000000 GPR24: c1441cec efffe153 e8001000 c14240c0 00000000 c1441d64 00000000 e8000000 NIP [c1020240] __alloc_bootmem_huge_page+0xd4/0x284 LR [c10201d0] __alloc_bootmem_huge_page+0x64/0x284 Call Trace: [c13fde20] [c10201d0] __alloc_bootmem_huge_page+0x64/0x284 (unreliable) [c13fde50] [c10207b8] hugetlb_hstate_alloc_pages+0x8c/0x3e8 [c13fdeb0] [c1021384] hugepages_setup+0x240/0x2cc [c13fdef0] [c1000574] unknown_bootoption+0xfc/0x280 [c13fdf30] [c0078904] parse_args+0x200/0x4c4 [c13fdfa0] [c1000d9c] start_kernel+0x238/0x7d0 [c13fdff0] [c0000434] set_ivor+0x12c/0x168 Code: 554aa33e 7c042840 3ce0c142 80a7427c 5109a016 50caa016 7c9a2378 7fdcf378 4180000c 7c052040 41810160 7c095040 <0fe00000> 38c00000 40800108 3c60c0eb ---[ end trace 0000000000000000 ]--- This is due to virt_addr_valid() using high_memory before it is set. high_memory is set in mem_init() using max_low_pfn, but max_low_pfn is available long before, it is set in mem_topology_setup(). So just like commit daa9ada2093e ("powerpc/mm: Fix boot crash with FLATMEM") moved the setting of max_mapnr immediately after the call to mem_topology_setup(), the same can be done for high_memory. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/62b69c4baad067093f39e7e60df0fe27a86b8d2a.1723100702.git.christophe.leroy@csgroup.eu Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-19powerpc: Avoid nmi_enter/nmi_exit in real mode interrupt.Mahesh Salgaonkar
commit 0db880fc865ffb522141ced4bfa66c12ab1fbb70 upstream. nmi_enter()/nmi_exit() touches per cpu variables which can lead to kernel crash when invoked during real mode interrupt handling (e.g. early HMI/MCE interrupt handler) if percpu allocation comes from vmalloc area. Early HMI/MCE handlers are called through DEFINE_INTERRUPT_HANDLER_NMI() wrapper which invokes nmi_enter/nmi_exit calls. We don't see any issue when percpu allocation is from the embedded first chunk. However with CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK enabled there are chances where percpu allocation can come from the vmalloc area. With kernel command line "percpu_alloc=page" we can force percpu allocation to come from vmalloc area and can see kernel crash in machine_check_early: [ 1.215714] NIP [c000000000e49eb4] rcu_nmi_enter+0x24/0x110 [ 1.215717] LR [c0000000000461a0] machine_check_early+0xf0/0x2c0 [ 1.215719] --- interrupt: 200 [ 1.215720] [c000000fffd73180] [0000000000000000] 0x0 (unreliable) [ 1.215722] [c000000fffd731b0] [0000000000000000] 0x0 [ 1.215724] [c000000fffd73210] [c000000000008364] machine_check_early_common+0x134/0x1f8 Fix this by avoiding use of nmi_enter()/nmi_exit() in real mode if percpu first chunk is not embedded. Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Tested-by: Shirisha Ganta <shirisha@linux.ibm.com> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20240410043006.81577-1-mahesh@linux.ibm.com [ Conflicts in arch/powerpc/include/asm/interrupt.h because machine_check_early() and machine_check_exception() has been refactored. ] Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-27powerpc/eeh: avoid possible crash when edev->pdev changesGanesh Goudar
[ Upstream commit a1216e62d039bf63a539bbe718536ec789a853dd ] If a PCI device is removed during eeh_pe_report_edev(), edev->pdev will change and can cause a crash, hold the PCI rescan/remove lock while taking a copy of edev->pdev->bus. Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20240617140240.580453-1-ganeshgr@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-05syscalls: fix compat_sys_io_pgetevents_time64 usageArnd Bergmann
commit d3882564a77c21eb746ba5364f3fa89b88de3d61 upstream. Using sys_io_pgetevents() as the entry point for compat mode tasks works almost correctly, but misses the sign extension for the min_nr and nr arguments. This was addressed on parisc by switching to compat_sys_io_pgetevents_time64() in commit 6431e92fc827 ("parisc: io_pgetevents_time64() needs compat syscall in 32-bit compat mode"), as well as by using more sophisticated system call wrappers on x86 and s390. However, arm64, mips, powerpc, sparc and riscv still have the same bug. Change all of them over to use compat_sys_io_pgetevents_time64() like parisc already does. This was clearly the intention when the function was originally added, but it got hooked up incorrectly in the tables. Cc: stable@vger.kernel.org Fixes: 48166e6ea47d ("y2038: add 64-bit time_t syscalls to all 32-bit architectures") Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390 Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-03-01powerpc/watchpoints: Annotate atomic context in more placesBenjamin Gray
[ Upstream commit 27646b2e02b096a6936b3e3b6ba334ae20763eab ] It can be easy to miss that the notifier mechanism invokes the callbacks in an atomic context, so add some comments to that effect on the two handlers we register here. Signed-off-by: Benjamin Gray <bgray@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230829063457.54157-4-bgray@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-01powerpc/watchpoint: Workaround P10 DD1 issue with VSX-32 byte instructionsRavi Bangoria
[ Upstream commit 3d2ffcdd2a982e8bbe65fa0f94fb21bf304c281e ] POWER10 DD1 has an issue where it generates watchpoint exceptions when it shouldn't. The conditions where this occur are: - octword op - ending address of DAWR range is less than starting address of op - those addresses need to be in the same or in two consecutive 512B blocks - 'op address + 64B' generates an address that has a carry into bit 52 (crosses 2K boundary) Handle such spurious exception by considering them as extraneous and emulating/single-steeping instruction without generating an event. [ravi: Fixed build warning reported by lkp@intel.com] Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201106045650.278987-1-ravi.bangoria@linux.ibm.com Stable-dep-of: 27646b2e02b0 ("powerpc/watchpoints: Annotate atomic context in more places") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-23powerpc: Fix build error due to is_valid_bugaddr()Michael Ellerman
[ Upstream commit f8d3555355653848082c351fa90775214fb8a4fa ] With CONFIG_GENERIC_BUG=n the build fails with: arch/powerpc/kernel/traps.c:1442:5: error: no previous prototype for ‘is_valid_bugaddr’ [-Werror=missing-prototypes] 1442 | int is_valid_bugaddr(unsigned long addr) | ^~~~~~~~~~~~~~~~ The prototype is only defined, and the function is only needed, when CONFIG_GENERIC_BUG=y, so move the implementation under that. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20231130114433.3053544-2-mpe@ellerman.id.au Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-15powerpc: update ppc_save_regs to save current r1 in pt_regsAditya Gupta
commit b684c09f09e7a6af3794d4233ef785819e72db79 upstream. ppc_save_regs() skips one stack frame while saving the CPU register states. Instead of saving current R1, it pulls the previous stack frame pointer. When vmcores caused by direct panic call (such as `echo c > /proc/sysrq-trigger`), are debugged with gdb, gdb fails to show the backtrace correctly. On further analysis, it was found that it was because of mismatch between r1 and NIP. GDB uses NIP to get current function symbol and uses corresponding debug info of that function to unwind previous frames, but due to the mismatching r1 and NIP, the unwinding does not work, and it fails to unwind to the 2nd frame and hence does not show the backtrace. GDB backtrace with vmcore of kernel without this patch: --------- (gdb) bt #0 0xc0000000002a53e8 in crash_setup_regs (oldregs=<optimized out>, newregs=0xc000000004f8f8d8) at ./arch/powerpc/include/asm/kexec.h:69 #1 __crash_kexec (regs=<optimized out>) at kernel/kexec_core.c:974 #2 0x0000000000000063 in ?? () #3 0xc000000003579320 in ?? () --------- Further analysis revealed that the mismatch occurred because "ppc_save_regs" was saving the previous stack's SP instead of the current r1. This patch fixes this by storing current r1 in the saved pt_regs. GDB backtrace with vmcore of patched kernel: -------- (gdb) bt #0 0xc0000000002a53e8 in crash_setup_regs (oldregs=0x0, newregs=0xc00000000670b8d8) at ./arch/powerpc/include/asm/kexec.h:69 #1 __crash_kexec (regs=regs@entry=0x0) at kernel/kexec_core.c:974 #2 0xc000000000168918 in panic (fmt=fmt@entry=0xc000000001654a60 "sysrq triggered crash\n") at kernel/panic.c:358 #3 0xc000000000b735f8 in sysrq_handle_crash (key=<optimized out>) at drivers/tty/sysrq.c:155 #4 0xc000000000b742cc in __handle_sysrq (key=key@entry=99, check_mask=check_mask@entry=false) at drivers/tty/sysrq.c:602 #5 0xc000000000b7506c in write_sysrq_trigger (file=<optimized out>, buf=<optimized out>, count=2, ppos=<optimized out>) at drivers/tty/sysrq.c:1163 #6 0xc00000000069a7bc in pde_write (ppos=<optimized out>, count=<optimized out>, buf=<optimized out>, file=<optimized out>, pde=0xc00000000362cb40) at fs/proc/inode.c:340 #7 proc_reg_write (file=<optimized out>, buf=<optimized out>, count=<optimized out>, ppos=<optimized out>) at fs/proc/inode.c:352 #8 0xc0000000005b3bbc in vfs_write (file=file@entry=0xc000000006aa6b00, buf=buf@entry=0x61f498b4f60 <error: Cannot access memory at address 0x61f498b4f60>, count=count@entry=2, pos=pos@entry=0xc00000000670bda0) at fs/read_write.c:582 #9 0xc0000000005b4264 in ksys_write (fd=<optimized out>, buf=0x61f498b4f60 <error: Cannot access memory at address 0x61f498b4f60>, count=2) at fs/read_write.c:637 #10 0xc00000000002ea2c in system_call_exception (regs=0xc00000000670be80, r0=<optimized out>) at arch/powerpc/kernel/syscall.c:171 #11 0xc00000000000c270 in system_call_vectored_common () at arch/powerpc/kernel/interrupt_64.S:192 -------- Nick adds: So this now saves regs as though it was an interrupt taken in the caller, at the instruction after the call to ppc_save_regs, whereas previously the NIP was there, but R1 came from the caller's caller and that mismatch is what causes gdb's dwarf unwinder to go haywire. Signed-off-by: Aditya Gupta <adityag@linux.ibm.com> Fixes: d16a58f8854b1 ("powerpc: Improve ppc_save_regs()") Reivewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230615091047.90433-1-adityag@linux.ibm.com Cc: stable@vger.kernel.org Signed-off-by: Aditya Gupta <adityag@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-20powerpc/ftrace: Fix stack teardown in ftrace_no_traceNaveen N Rao
commit 4b3338aaa74d7d4ec5b6734dc298f0db94ec83d2 upstream. Commit 41a506ef71eb ("powerpc/ftrace: Create a dummy stackframe to fix stack unwind") added use of a new stack frame on ftrace entry to fix stack unwind. However, the commit missed updating the offset used while tearing down the ftrace stack when ftrace is disabled. Fix the same. In addition, the commit missed saving the correct stack pointer in pt_regs. Update the same. Fixes: 41a506ef71eb ("powerpc/ftrace: Create a dummy stackframe to fix stack unwind") Cc: stable@vger.kernel.org # v6.5+ Signed-off-by: Naveen N Rao <naveen@kernel.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20231130065947.2188860-1-naveen@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-20powerpc/ftrace: Create a dummy stackframe to fix stack unwindNaveen N Rao
commit 41a506ef71eb38d94fe133f565c87c3e06ccc072 upstream. With ppc64 -mprofile-kernel and ppc32 -pg, profiling instructions to call into ftrace are emitted right at function entry. The instruction sequence used is minimal to reduce overhead. Crucially, a stackframe is not created for the function being traced. This breaks stack unwinding since the function being traced does not have a stackframe for itself. As such, it never shows up in the backtrace: /sys/kernel/debug/tracing # echo 1 > /proc/sys/kernel/stack_tracer_enabled /sys/kernel/debug/tracing # cat stack_trace Depth Size Location (17 entries) ----- ---- -------- 0) 4144 32 ftrace_call+0x4/0x44 1) 4112 432 get_page_from_freelist+0x26c/0x1ad0 2) 3680 496 __alloc_pages+0x290/0x1280 3) 3184 336 __folio_alloc+0x34/0x90 4) 2848 176 vma_alloc_folio+0xd8/0x540 5) 2672 272 __handle_mm_fault+0x700/0x1cc0 6) 2400 208 handle_mm_fault+0xf0/0x3f0 7) 2192 80 ___do_page_fault+0x3e4/0xbe0 8) 2112 160 do_page_fault+0x30/0xc0 9) 1952 256 data_access_common_virt+0x210/0x220 10) 1696 400 0xc00000000f16b100 11) 1296 384 load_elf_binary+0x804/0x1b80 12) 912 208 bprm_execve+0x2d8/0x7e0 13) 704 64 do_execveat_common+0x1d0/0x2f0 14) 640 160 sys_execve+0x54/0x70 15) 480 64 system_call_exception+0x138/0x350 16) 416 416 system_call_common+0x160/0x2c4 Fix this by having ftrace create a dummy stackframe for the function being traced. With this, backtraces now capture the function being traced: /sys/kernel/debug/tracing # cat stack_trace Depth Size Location (17 entries) ----- ---- -------- 0) 3888 32 _raw_spin_trylock+0x8/0x70 1) 3856 576 get_page_from_freelist+0x26c/0x1ad0 2) 3280 64 __alloc_pages+0x290/0x1280 3) 3216 336 __folio_alloc+0x34/0x90 4) 2880 176 vma_alloc_folio+0xd8/0x540 5) 2704 416 __handle_mm_fault+0x700/0x1cc0 6) 2288 96 handle_mm_fault+0xf0/0x3f0 7) 2192 48 ___do_page_fault+0x3e4/0xbe0 8) 2144 192 do_page_fault+0x30/0xc0 9) 1952 608 data_access_common_virt+0x210/0x220 10) 1344 16 0xc0000000334bbb50 11) 1328 416 load_elf_binary+0x804/0x1b80 12) 912 64 bprm_execve+0x2d8/0x7e0 13) 848 176 do_execveat_common+0x1d0/0x2f0 14) 672 192 sys_execve+0x54/0x70 15) 480 64 system_call_exception+0x138/0x350 16) 416 416 system_call_common+0x160/0x2c4 This results in two additional stores in the ftrace entry code, but produces reliable backtraces. Fixes: 153086644fd1 ("powerpc/ftrace: Add support for -mprofile-kernel ftrace ABI") Cc: stable@vger.kernel.org Signed-off-by: Naveen N Rao <naveen@kernel.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230621051349.759567-1-naveen@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-08powerpc: Don't clobber f0/vs0 during fp|altivec register saveTimothy Pearson
commit 5e1d824f9a283cbf90f25241b66d1f69adb3835b upstream. During floating point and vector save to thread data f0/vs0 are clobbered by the FPSCR/VSCR store routine. This has been obvserved to lead to userspace register corruption and application data corruption with io-uring. Fix it by restoring f0/vs0 after FPSCR/VSCR store has completed for all the FP, altivec, VMX register save paths. Tested under QEMU in kvm mode, running on a Talos II workstation with dual POWER9 DD2.2 CPUs. Additional detail (mpe): Typically save_fpu() is called from __giveup_fpu() which saves the FP regs and also *turns off FP* in the tasks MSR, meaning the kernel will reload the FP regs from the thread struct before letting the task use FP again. So in that case save_fpu() is free to clobber f0 because the FP regs no longer hold live values for the task. There is another case though, which is the path via: sys_clone() ... copy_process() dup_task_struct() arch_dup_task_struct() flush_all_to_thread() save_all() That path saves the FP regs but leaves them live. That's meant as an optimisation for a process that's using FP/VSX and then calls fork(), leaving the regs live means the parent process doesn't have to take a fault after the fork to get its FP regs back. The optimisation was added in commit 8792468da5e1 ("powerpc: Add the ability to save FPU without giving it up"). That path does clobber f0, but f0 is volatile across function calls, and typically programs reach copy_process() from userspace via a syscall wrapper function. So in normal usage f0 being clobbered across a syscall doesn't cause visible data corruption. But there is now a new path, because io-uring can call copy_process() via create_io_thread() from the signal handling path. That's OK if the signal is handled as part of syscall return, but it's not OK if the signal is handled due to some other interrupt. That path is: interrupt_return_srr_user() interrupt_exit_user_prepare() interrupt_exit_user_prepare_main() do_notify_resume() get_signal() task_work_run() create_worker_cb() create_io_worker() copy_process() dup_task_struct() arch_dup_task_struct() flush_all_to_thread() save_all() if (tsk->thread.regs->msr & MSR_FP) save_fpu() # f0 is clobbered and potentially live in userspace Note the above discussion applies equally to save_altivec(). Fixes: 8792468da5e1 ("powerpc: Add the ability to save FPU without giving it up") Cc: stable@vger.kernel.org # v4.6+ Closes: https://lore.kernel.org/all/480932026.45576726.1699374859845.JavaMail.zimbra@raptorengineeringinc.com/ Closes: https://lore.kernel.org/linuxppc-dev/480221078.47953493.1700206777956.JavaMail.zimbra@raptorengineeringinc.com/ Tested-by: Timothy Pearson <tpearson@raptorengineering.com> Tested-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Timothy Pearson <tpearson@raptorengineering.com> [mpe: Reword change log to describe exact path of corruption & other minor tweaks] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/1921539696.48534988.1700407082933.JavaMail.zimbra@raptorengineeringinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-08powerpc/mm: Fix boot crash with FLATMEMMichael Ellerman
[ Upstream commit daa9ada2093ed23d52b4c1fe6e13cf78f55cc85f ] Erhard reported that his G5 was crashing with v6.6-rc kernels: mpic: Setting up HT PICs workarounds for U3/U4 BUG: Unable to handle kernel data access at 0xfeffbb62ffec65fe Faulting instruction address: 0xc00000000005dc40 Oops: Kernel access of bad area, sig: 11 [#1] BE PAGE_SIZE=4K MMU=Hash SMP NR_CPUS=2 PowerMac Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Tainted: G T 6.6.0-rc3-PMacGS #1 Hardware name: PowerMac11,2 PPC970MP 0x440101 PowerMac NIP: c00000000005dc40 LR: c000000000066660 CTR: c000000000007730 REGS: c0000000022bf510 TRAP: 0380 Tainted: G T (6.6.0-rc3-PMacGS) MSR: 9000000000001032 <SF,HV,ME,IR,DR,RI> CR: 44004242 XER: 00000000 IRQMASK: 3 GPR00: 0000000000000000 c0000000022bf7b0 c0000000010c0b00 00000000000001ac GPR04: 0000000003c80000 0000000000000300 c0000000f20001ae 0000000000000300 GPR08: 0000000000000006 feffbb62ffec65ff 0000000000000001 0000000000000000 GPR12: 9000000000001032 c000000002362000 c000000000f76b80 000000000349ecd8 GPR16: 0000000002367ba8 0000000002367f08 0000000000000006 0000000000000000 GPR20: 00000000000001ac c000000000f6f920 c0000000022cd985 000000000000000c GPR24: 0000000000000300 00000003b0a3691d c0003e008030000e 0000000000000000 GPR28: c00000000000000c c0000000f20001ee feffbb62ffec65fe 00000000000001ac NIP hash_page_do_lazy_icache+0x50/0x100 LR __hash_page_4K+0x420/0x590 Call Trace: hash_page_mm+0x364/0x6f0 do_hash_fault+0x114/0x2b0 data_access_common_virt+0x198/0x1f0 --- interrupt: 300 at mpic_init+0x4bc/0x10c4 NIP: c000000002020a5c LR: c000000002020a04 CTR: 0000000000000000 REGS: c0000000022bf9f0 TRAP: 0300 Tainted: G T (6.6.0-rc3-PMacGS) MSR: 9000000000001032 <SF,HV,ME,IR,DR,RI> CR: 24004248 XER: 00000000 DAR: c0003e008030000e DSISR: 40000000 IRQMASK: 1 ... NIP mpic_init+0x4bc/0x10c4 LR mpic_init+0x464/0x10c4 --- interrupt: 300 pmac_setup_one_mpic+0x258/0x2dc pmac_pic_init+0x28c/0x3d8 init_IRQ+0x90/0x140 start_kernel+0x57c/0x78c start_here_common+0x1c/0x20 A bisect pointed to the breakage beginning with commit 9fee28baa601 ("powerpc: implement the new page table range API"). Analysis of the oops pointed to a struct page with a corrupted compound_head being loaded via page_folio() -> _compound_head() in hash_page_do_lazy_icache(). The access by the mpic code is to an MMIO address, so the expectation is that the struct page for that address would be initialised by init_unavailable_range(), as pointed out by Aneesh. Instrumentation showed that was not the case, which eventually lead to the realisation that pfn_valid() was returning false for that address, causing the struct page to not be initialised. Because the system is using FLATMEM, the version of pfn_valid() in memory_model.h is used: static inline int pfn_valid(unsigned long pfn) { ... return pfn >= pfn_offset && (pfn - pfn_offset) < max_mapnr; } Which relies on max_mapnr being initialised. Early in boot max_mapnr is zero meaning no PFNs are valid. max_mapnr is initialised in mem_init() called via: start_kernel() mm_core_init() # init/main.c:928 mem_init() But that is too late for the usage in init_unavailable_range() called via: start_kernel() setup_arch() # init/main.c:893 paging_init() free_area_init() init_unavailable_range() Although max_mapnr is currently set in mem_init(), the value is actually already available much earlier, as soon as mem_topology_setup() has completed, which is also before paging_init() is called. So move the initialisation there, which causes paging_init() to correctly initialise the struct page and fixes the bug. This bug seems to have been lurking for years, but went unnoticed because the pre-folio code was inspecting the uninitialised page->flags but not dereferencing it. Thanks to Erhard and Aneesh for help debugging. Reported-by: Erhard Furtner <erhard_f@mailbox.org> Closes: https://lore.kernel.org/all/20230929132750.3cd98452@yea/ Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20231023112500.1550208-1-mpe@ellerman.id.au Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-10-10powerpc/watchpoints: Disable preemption in thread_change_pc()Benjamin Gray
[ Upstream commit cc879ab3ce39bc39f9b1d238b283f43a5f6f957d ] thread_change_pc() uses CPU local data, so must be protected from swapping CPUs while it is reading the breakpoint struct. The error is more noticeable after 1e60f3564bad ("powerpc/watchpoints: Track perf single step directly on the breakpoint"), which added an unconditional __this_cpu_read() call in thread_change_pc(). However the existing __this_cpu_read() that runs if a breakpoint does need to be re-inserted has the same issue. Signed-off-by: Benjamin Gray <bgray@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230829063457.54157-2-bgray@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-19powerpc/iommu: Fix notifiers being shared by PCI and VIO busesRussell Currey
[ Upstream commit c37b6908f7b2bd24dcaaf14a180e28c9132b9c58 ] fail_iommu_setup() registers the fail_iommu_bus_notifier struct to both PCI and VIO buses. struct notifier_block is a linked list node, so this causes any notifiers later registered to either bus type to also be registered to the other since they share the same node. This causes issues in (at least) the vgaarb code, which registers a notifier for PCI buses. pci_notify() ends up being called on a vio device, converted with to_pci_dev() even though it's not a PCI device, and finally makes a bad access in vga_arbiter_add_pci_device() as discovered with KASAN: BUG: KASAN: slab-out-of-bounds in vga_arbiter_add_pci_device+0x60/0xe00 Read of size 4 at addr c000000264c26fdc by task swapper/0/1 Call Trace: dump_stack_lvl+0x1bc/0x2b8 (unreliable) print_report+0x3f4/0xc60 kasan_report+0x244/0x698 __asan_load4+0xe8/0x250 vga_arbiter_add_pci_device+0x60/0xe00 pci_notify+0x88/0x444 notifier_call_chain+0x104/0x320 blocking_notifier_call_chain+0xa0/0x140 device_add+0xac8/0x1d30 device_register+0x58/0x80 vio_register_device_node+0x9ac/0xce0 vio_bus_scan_register_devices+0xc4/0x13c __machine_initcall_pseries_vio_device_init+0x94/0xf0 do_one_initcall+0x12c/0xaa8 kernel_init_freeable+0xa48/0xba8 kernel_init+0x64/0x400 ret_from_kernel_thread+0x5c/0x64 Fix this by creating separate notifier_block structs for each bus type. Fixes: d6b9a81b2a45 ("powerpc: IOMMU fault injection") Reported-by: Nageswara R Sastry <rnsastry@linux.ibm.com> Signed-off-by: Russell Currey <ruscur@russell.cc> Tested-by: Nageswara R Sastry <rnsastry@linux.ibm.com> Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com> [mpe: Add #ifdef to fix CONFIG_IBMVIO=n build] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230322035322.328709-1-ruscur@russell.cc Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-19powerpc/fadump: reset dump area size if fadump memory reserve failsSourabh Jain
[ Upstream commit d1eb75e0dfed80d2d85b664e28a39f65b290ab55 ] In case fadump_reserve_mem() fails to reserve memory, the reserve_dump_area_size variable will retain the reserve area size. This will lead to /sys/kernel/fadump/mem_reserved node displaying an incorrect memory reserved by fadump. To fix this problem, reserve dump area size variable is set to 0 if fadump failed to reserve memory. Fixes: 8255da95e545 ("powerpc/fadump: release all the memory above boot memory size") Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com> Acked-by: Mahesh Salgaonkar <mahesh@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230704050715.203581-1-sourabhjain@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-08-26powerpc/rtas_flash: allow user copy to flash block cache objectsNathan Lynch
commit 4f3175979e62de3b929bfa54a0db4b87d36257a7 upstream. With hardened usercopy enabled (CONFIG_HARDENED_USERCOPY=y), using the /proc/powerpc/rtas/firmware_update interface to prepare a system firmware update yields a BUG(): kernel BUG at mm/usercopy.c:102! Oops: Exception in kernel mode, sig: 5 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries Modules linked in: CPU: 0 PID: 2232 Comm: dd Not tainted 6.5.0-rc3+ #2 Hardware name: IBM,8408-E8E POWER8E (raw) 0x4b0201 0xf000004 of:IBM,FW860.50 (SV860_146) hv:phyp pSeries NIP: c0000000005991d0 LR: c0000000005991cc CTR: 0000000000000000 REGS: c0000000148c76a0 TRAP: 0700 Not tainted (6.5.0-rc3+) MSR: 8000000000029033 <SF,EE,ME,IR,DR,RI,LE> CR: 24002242 XER: 0000000c CFAR: c0000000001fbd34 IRQMASK: 0 [ ... GPRs omitted ... ] NIP usercopy_abort+0xa0/0xb0 LR usercopy_abort+0x9c/0xb0 Call Trace: usercopy_abort+0x9c/0xb0 (unreliable) __check_heap_object+0x1b4/0x1d0 __check_object_size+0x2d0/0x380 rtas_flash_write+0xe4/0x250 proc_reg_write+0xfc/0x160 vfs_write+0xfc/0x4e0 ksys_write+0x90/0x160 system_call_exception+0x178/0x320 system_call_common+0x160/0x2c4 The blocks of the firmware image are copied directly from user memory to objects allocated from flash_block_cache, so flash_block_cache must be created using kmem_cache_create_usercopy() to mark it safe for user access. Fixes: 6d07d1cd300f ("usercopy: Restrict non-usercopy caches to size 0") Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Kees Cook <keescook@chromium.org> [mpe: Trim and indent oops] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230810-rtas-flash-vs-hardened-usercopy-v2-1-dcf63793a938@linux.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-17powerpc/rtas: use memmove for potentially overlapping buffer copyNathan Lynch
[ Upstream commit 271208ee5e335cb1ad280d22784940daf7ddf820 ] Using memcpy() isn't safe when buf is identical to rtas_err_buf, which can happen during boot before slab is up. Full context which may not be obvious from the diff: if (altbuf) { buf = altbuf; } else { buf = rtas_err_buf; if (slab_is_available()) buf = kmalloc(RTAS_ERROR_LOG_MAX, GFP_ATOMIC); } if (buf) memcpy(buf, rtas_err_buf, RTAS_ERROR_LOG_MAX); This was found by inspection and I'm not aware of it causing problems in practice. It appears to have been introduced by commit 033ef338b6e0 ("powerpc: Merge rtas.c into arch/powerpc/kernel"); the old ppc64 version of this code did not have this problem. Use memmove() instead. Fixes: 033ef338b6e0 ("powerpc: Merge rtas.c into arch/powerpc/kernel") Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230220-rtas-queue-for-6-4-v1-2-010e4416f13f@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-04-20powerpc/pseries: Add support for FORM2 associativityAneesh Kumar K.V
[ Upstream commit 1c6b5a7e74052768977855f95d6b8812f6e7772c ] PAPR interface currently supports two different ways of communicating resource grouping details to the OS. These are referred to as Form 0 and Form 1 associativity grouping. Form 0 is the older format and is now considered deprecated. This patch adds another resource grouping named FORM2. Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210812132223.225214-6-aneesh.kumar@linux.ibm.com Stable-dep-of: b277fc793daf ("powerpc/papr_scm: Update the NUMA distance table for the target node") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-04-20powerpc/pseries: Rename TYPE1_AFFINITY to FORM1_AFFINITYAneesh Kumar K.V
[ Upstream commit 0eacd06bb8adea8dd9edb0a30144166d9f227e64 ] Also make related code cleanup that will allow adding FORM2_AFFINITY in later patches. No functional change in this patch. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210812132223.225214-3-aneesh.kumar@linux.ibm.com Stable-dep-of: b277fc793daf ("powerpc/papr_scm: Update the NUMA distance table for the target node") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-04-05powerpc: Don't try to copy PPR for task with NULL pt_regsJens Axboe
commit fd7276189450110ed835eb0a334e62d2f1c4e3be upstream. powerpc sets up PF_KTHREAD and PF_IO_WORKER with a NULL pt_regs, which from my (arguably very short) checking is not commonly done for other archs. This is fine, except when PF_IO_WORKER's have been created and the task does something that causes a coredump to be generated. Then we get this crash: Kernel attempted to read user page (160) - exploit attempt? (uid: 1000) BUG: Kernel NULL pointer dereference on read at 0x00000160 Faulting instruction address: 0xc0000000000c3a60 Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=32 NUMA pSeries Modules linked in: bochs drm_vram_helper drm_kms_helper xts binfmt_misc ecb ctr syscopyarea sysfillrect cbc sysimgblt drm_ttm_helper aes_generic ttm sg libaes evdev joydev virtio_balloon vmx_crypto gf128mul drm dm_mod fuse loop configfs drm_panel_orientation_quirks ip_tables x_tables autofs4 hid_generic usbhid hid xhci_pci xhci_hcd usbcore usb_common sd_mod CPU: 1 PID: 1982 Comm: ppc-crash Not tainted 6.3.0-rc2+ #88 Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,HEAD hv:linux,kvm pSeries NIP: c0000000000c3a60 LR: c000000000039944 CTR: c0000000000398e0 REGS: c0000000041833b0 TRAP: 0300 Not tainted (6.3.0-rc2+) MSR: 800000000280b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 88082828 XER: 200400f8 ... NIP memcpy_power7+0x200/0x7d0 LR ppr_get+0x64/0xb0 Call Trace: ppr_get+0x40/0xb0 (unreliable) __regset_get+0x180/0x1f0 regset_get_alloc+0x64/0x90 elf_core_dump+0xb98/0x1b60 do_coredump+0x1c34/0x24a0 get_signal+0x71c/0x1410 do_notify_resume+0x140/0x6f0 interrupt_exit_user_prepare_main+0x29c/0x320 interrupt_exit_user_prepare+0x6c/0xa0 interrupt_return_srr_user+0x8/0x138 Because ppr_get() is trying to copy from a PF_IO_WORKER with a NULL pt_regs. Check for a valid pt_regs in both ppc_get/ppr_set, and return an error if not set. The actual error value doesn't seem to be important here, so just pick -EINVAL. Fixes: fa439810cc1b ("powerpc/ptrace: Enable support for NT_PPPC_TAR, NT_PPC_PPR, NT_PPC_DSCR") Cc: stable@vger.kernel.org # v4.8+ Signed-off-by: Jens Axboe <axboe@kernel.dk> [mpe: Trim oops in change log, add Fixes & Cc stable] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/d9f63344-fe7c-56ae-b420-4a1a04a2ae4c@kernel.dk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17powerpc/vmlinux.lds: Don't discard .rela* for relocatable buildsMichael Ellerman
commit 07b050f9290ee012a407a0f64151db902a1520f5 upstream. Relocatable kernels must not discard relocations, they need to be processed at runtime. As such they are included for CONFIG_RELOCATABLE builds in the powerpc linker script (line 340). However they are also unconditionally discarded later in the script (line 414). Previously that worked because the earlier inclusion superseded the discard. However commit 99cb0d917ffa ("arch: fix broken BuildID for arm64 and riscv") introduced an earlier use of DISCARD as part of the RO_DATA macro (line 137). With binutils < 2.36 that causes the DISCARD directives later in the script to be applied earlier, causing .rela* to actually be discarded at link time, leading to build warnings and a kernel that doesn't boot: ld: warning: discarding dynamic section .rela.init.rodata Fix it by conditionally discarding .rela* only when CONFIG_RELOCATABLE is disabled. Fixes: 99cb0d917ffa ("arch: fix broken BuildID for arm64 and riscv") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20230105132349.384666-2-mpe@ellerman.id.au Signed-off-by: Tom Saeger <tom.saeger@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17powerpc/vmlinux.lds: Define RUNTIME_DISCARD_EXITMichael Ellerman
commit 4b9880dbf3bdba3a7c56445137c3d0e30aaa0a40 upstream. The powerpc linker script explicitly includes .exit.text, because otherwise the link fails due to references from __bug_table and __ex_table. The code is freed (discarded) at runtime along with .init.text and data. That has worked in the past despite powerpc not defining RUNTIME_DISCARD_EXIT because DISCARDS appears late in the powerpc linker script (line 410), and the explicit inclusion of .exit.text earlier (line 280) supersedes the discard. However commit 99cb0d917ffa ("arch: fix broken BuildID for arm64 and riscv") introduced an earlier use of DISCARD as part of the RO_DATA macro (line 136). With binutils < 2.36 that causes the DISCARD directives later in the script to be applied earlier [1], causing .exit.text to actually be discarded at link time, leading to build errors: '.exit.text' referenced in section '__bug_table' of crypto/algboss.o: defined in discarded section '.exit.text' of crypto/algboss.o '.exit.text' referenced in section '__ex_table' of drivers/nvdimm/core.o: defined in discarded section '.exit.text' of drivers/nvdimm/core.o Fix it by defining RUNTIME_DISCARD_EXIT, which causes the generic DISCARDS macro to not include .exit.text at all. 1: https://lore.kernel.org/lkml/87fscp2v7k.fsf@igel.home/ Fixes: 99cb0d917ffa ("arch: fix broken BuildID for arm64 and riscv") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20230105132349.384666-1-mpe@ellerman.id.au Signed-off-by: Tom Saeger <tom.saeger@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17powerpc/kcsan: Exclude udelay to prevent recursive instrumentationRohan McLure
[ Upstream commit 2a7ce82dc46c591c9244057d89a6591c9639b9b9 ] In order for KCSAN to increase its likelihood of observing a data race, it sets a watchpoint on memory accesses and stalls, allowing for detection of conflicting accesses by other kernel threads or interrupts. Stalls are implemented by injecting a call to udelay in instrumented code. To prevent recursive instrumentation, exclude udelay from being instrumented. Signed-off-by: Rohan McLure <rmclure@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20230206021801.105268-3-rmclure@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11powerpc/eeh: Set channel state after notifying the driversGanesh Goudar
[ Upstream commit 9efcdaac36e1643a1b7f5337e6143ce142d381b1 ] When a PCI error is encountered 6th time in an hour we set the channel state to perm_failure and notify the driver about the permanent failure. However, after upstream commit 38ddc011478e ("powerpc/eeh: Make permanently failed devices non-actionable"), EEH handler stops calling any routine once the device is marked as permanent failure. This issue can lead to fatal consequences like kernel hang with certain PCI devices. Following log is observed with lpfc driver, with and without this change, Without this change kernel hangs, If PCI error is encountered 6 times for a device in an hour. Without the change EEH: Beginning: 'error_detected(permanent failure)' PCI 0132:60:00.0#600000: EEH: not actionable (1,1,1) PCI 0132:60:00.1#600000: EEH: not actionable (1,1,1) EEH: Finished:'error_detected(permanent failure)' With the change EEH: Beginning: 'error_detected(permanent failure)' EEH: Invoking lpfc->error_detected(permanent failure) EEH: lpfc driver reports: 'disconnect' EEH: Invoking lpfc->error_detected(permanent failure) EEH: lpfc driver reports: 'disconnect' EEH: Finished:'error_detected(permanent failure)' To fix the issue, set channel state to permanent failure after notifying the drivers. Fixes: 38ddc011478e ("powerpc/eeh: Make permanently failed devices non-actionable") Suggested-by: Mahesh Salgaonkar <mahesh@linux.ibm.com> Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20230209105649.127707-1-ganeshgr@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11powerpc/eeh: Small refactor of eeh_handle_normal_event()Daniel Axtens
[ Upstream commit 10b34ece132ee46dc4e6459c765d180c422a09fa ] The control flow of eeh_handle_normal_event() is a bit tricky. Break out one of the error handling paths - rather than be in an else block, we'll make it part of the regular body of the function and put a 'goto out;' in the true limb of the if. Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211015070628.1331635-1-dja@axtens.net Stable-dep-of: 9efcdaac36e1 ("powerpc/eeh: Set channel state after notifying the drivers") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11powerpc/rtas: ensure 4KB alignment for rtas_data_bufNathan Lynch
[ Upstream commit 836b5b9fcc8e09cea7e8a59a070349a00e818308 ] Some RTAS functions that have work area parameters impose alignment requirements on the work area passed to them by the OS. Examples include: - ibm,configure-connector - ibm,update-nodes - ibm,update-properties 4KB is the greatest alignment required by PAPR for such buffers. rtas_data_buf used to have a __page_aligned attribute in the arch/ppc64 days, but that was changed to __cacheline_aligned for unknown reasons by commit 033ef338b6e0 ("powerpc: Merge rtas.c into arch/powerpc/kernel"). That works out to 128-byte alignment on ppc64, which isn't right. This was found by inspection and I'm not aware of any real problems caused by this. Either current RTAS implementations don't enforce the alignment constraints, or rtas_data_buf is always being placed at a 4KB boundary by accident (or both, perhaps). Use __aligned(SZ_4K) to ensure the rtas_data_buf has alignment appropriate for all users. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Fixes: 033ef338b6e0 ("powerpc: Merge rtas.c into arch/powerpc/kernel") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20230125-b4-powerpc-rtas-queue-v3-6-26929c8cce78@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11powerpc/rtas: make all exports GPLNathan Lynch
[ Upstream commit 9bce6243848dfd0ff7c2be6e8d82ab9b1e6c7858 ] The first symbol exports of RTAS functions and data came with the (now removed) scanlog driver in 2003: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/?id=f92e361842d5251e50562b09664082dcbd0548bb At the time this was applied, EXPORT_SYMBOL_GPL() was very new, and the exports of rtas_call() etc have remained non-GPL. As new APIs have been added to the RTAS subsystem, their symbol exports have followed the convention set by existing code. However, the historical evidence is that RTAS function exports have been added over time only to satisfy the needs of in-kernel users, and these clients must have fairly intimate knowledge of how the APIs work to use them safely. No out of tree users are known, and future ones seem unlikely. Arguably the default for RTAS symbols should have become EXPORT_SYMBOL_GPL once it was available. Let's make it so now, and exceptions can be evaluated as needed. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Laurent Dufour <laurent.dufour@fr.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20230124140448.45938-3-nathanl@linux.ibm.com Stable-dep-of: 836b5b9fcc8e ("powerpc/rtas: ensure 4KB alignment for rtas_data_buf") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-02-01exit: Add and use make_task_dead.Eric W. Biederman
commit 0e25498f8cd43c1b5aa327f373dd094e9a006da7 upstream. There are two big uses of do_exit. The first is it's design use to be the guts of the exit(2) system call. The second use is to terminate a task after something catastrophic has happened like a NULL pointer in kernel code. Add a function make_task_dead that is initialy exactly the same as do_exit to cover the cases where do_exit is called to handle catastrophic failure. In time this can probably be reduced to just a light wrapper around do_task_dead. For now keep it exactly the same so that there will be no behavioral differences introducing this new concept. Replace all of the uses of do_exit that use it for catastraphic task cleanup with make_task_dead to make it clear what the code is doing. As part of this rename rewind_stack_do_exit rewind_stack_and_make_dead. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14powerpc/rtas: avoid scheduling in rtas_os_term()Nathan Lynch
[ Upstream commit 6c606e57eecc37d6b36d732b1ff7e55b7dc32dd4 ] It's unsafe to use rtas_busy_delay() to handle a busy status from the ibm,os-term RTAS function in rtas_os_term(): Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b BUG: sleeping function called from invalid context at arch/powerpc/kernel/rtas.c:618 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 1, name: swapper/0 preempt_count: 2, expected: 0 CPU: 7 PID: 1 Comm: swapper/0 Tainted: G D 6.0.0-rc5-02182-gf8553a572277-dirty #9 Call Trace: [c000000007b8f000] [c000000001337110] dump_stack_lvl+0xb4/0x110 (unreliable) [c000000007b8f040] [c0000000002440e4] __might_resched+0x394/0x3c0 [c000000007b8f0e0] [c00000000004f680] rtas_busy_delay+0x120/0x1b0 [c000000007b8f100] [c000000000052d04] rtas_os_term+0xb8/0xf4 [c000000007b8f180] [c0000000001150fc] pseries_panic+0x50/0x68 [c000000007b8f1f0] [c000000000036354] ppc_panic_platform_handler+0x34/0x50 [c000000007b8f210] [c0000000002303c4] notifier_call_chain+0xd4/0x1c0 [c000000007b8f2b0] [c0000000002306cc] atomic_notifier_call_chain+0xac/0x1c0 [c000000007b8f2f0] [c0000000001d62b8] panic+0x228/0x4d0 [c000000007b8f390] [c0000000001e573c] do_exit+0x140c/0x1420 [c000000007b8f480] [c0000000001e586c] make_task_dead+0xdc/0x200 Use rtas_busy_delay_time() instead, which signals without side effects whether to attempt the ibm,os-term RTAS call again. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221118150751.469393-5-nathanl@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14powerpc/rtas: avoid device tree lookups in rtas_os_term()Nathan Lynch
[ Upstream commit ed2213bfb192ab51f09f12e9b49b5d482c6493f3 ] rtas_os_term() is called during panic. Its behavior depends on a couple of conditions in the /rtas node of the device tree, the traversal of which entails locking and local IRQ state changes. If the kernel panics while devtree_lock is held, rtas_os_term() as currently written could hang. Instead of discovering the relevant characteristics at panic time, cache them in file-static variables at boot. Note the lookup for "ibm,extended-os-term" is converted to of_property_read_bool() since it is a boolean property, not an RTAS function token. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com> [mpe: Incorporate suggested change from Nick] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221118150751.469393-4-nathanl@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-04arch: ensure parisc/powerpc handle PF_IO_WORKER in copy_thread()Jens Axboe
[ Upstream commit 0100e6bbdbb79404e56939313662b42737026574 ] In the arch addition of PF_IO_WORKER, I missed parisc and powerpc for some reason. Fix that up, ensuring they handle PF_IO_WORKER like they do PF_KTHREAD in copy_thread(). Reported-by: Bruno Goncalves <bgoncalv@redhat.com> Fixes: 4727dc20e042 ("arch: setup PF_IO_WORKER threads like PF_KTHREAD") Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-04powerpc: add support for TIF_NOTIFY_SIGNALJens Axboe
[ Upstream commit 900f0713fdd730fab0f0bfa4a8ca4db2a8985bbe ] Wire up TIF_NOTIFY_SIGNAL handling for powerpc. Cc: linuxppc-dev@lists.ozlabs.org Acked-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26powerpc/pci_dn: Add missing of_node_put()Liang He
[ Upstream commit 110a1fcb6c4d55144d8179983a475f17a1d6f832 ] In pci_add_device_node_info(), use of_node_put() to drop the reference to 'parent' returned by of_get_parent() to keep refcount balance. Fixes: cca87d303c85 ("powerpc/pci: Refactor pci_dn") Co-authored-by: Miaoqian Lin <linmq006@gmail.com> Signed-off-by: Liang He <windhl@126.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com> Link: https://lore.kernel.org/r/20220701131750.240170-1-windhl@126.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-08powerpc: align syscall table for ppc32Masahiro Yamada
commit c7acee3d2f128a38b68fb7af85dbbd91bfd0b4ad upstream. Christophe Leroy reported that commit 7b4537199a4a ("kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS") broke mpc85xx_defconfig + CONFIG_RELOCATABLE=y. LD vmlinux SYSMAP System.map SORTTAB vmlinux CHKREL vmlinux WARNING: 451 bad relocations c0b312a9 R_PPC_UADDR32 .head.text-0x3ff9ed54 c0b312ad R_PPC_UADDR32 .head.text-0x3ffac224 c0b312b1 R_PPC_UADDR32 .head.text-0x3ffb09f4 c0b312b5 R_PPC_UADDR32 .head.text-0x3fe184dc c0b312b9 R_PPC_UADDR32 .head.text-0x3fe183a8 ... The compiler emits a bunch of R_PPC_UADDR32, which is not supported by arch/powerpc/kernel/reloc_32.S. The reason is there exists an unaligned symbol. $ powerpc-linux-gnu-nm -n vmlinux ... c0b31258 d spe_aligninfo c0b31298 d __func__.0 c0b312a9 D sys_call_table c0b319b8 d __func__.0 Commit 7b4537199a4a is not the root cause. Even before that, I can reproduce the same issue for mpc85xx_defconfig + CONFIG_RELOCATABLE=y + CONFIG_MODVERSIONS=n. It is just that nobody noticed because when CONFIG_MODVERSIONS is enabled, a __crc_* symbol inserted before sys_call_table was hiding the unalignment issue. Adding alignment to the syscall table for ppc32 fixes the issue. Cc: stable@vger.kernel.org Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Trim change log discussion, add Cc stable] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/lkml/38605f6a-a568-f884-f06f-ea4da5b214f0@csgroup.eu/ Link: https://lore.kernel.org/r/20220820165129.1147589-1-masahiroy@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-25powerpc/64: Init jump labels before parse_early_param()Zhouyi Zhou
[ Upstream commit ca829e05d3d4f728810cc5e4b468d9ebc7745eb3 ] On 64-bit, calling jump_label_init() in setup_feature_keys() is too late because static keys may be used in subroutines of parse_early_param() which is again subroutine of early_init_devtree(). For example booting with "threadirqs": static_key_enable_cpuslocked(): static key '0xc000000002953260' used before call to jump_label_init() WARNING: CPU: 0 PID: 0 at kernel/jump_label.c:166 static_key_enable_cpuslocked+0xfc/0x120 ... NIP static_key_enable_cpuslocked+0xfc/0x120 LR static_key_enable_cpuslocked+0xf8/0x120 Call Trace: static_key_enable_cpuslocked+0xf8/0x120 (unreliable) static_key_enable+0x30/0x50 setup_forced_irqthreads+0x28/0x40 do_early_param+0xa0/0x108 parse_args+0x290/0x4e0 parse_early_options+0x48/0x5c parse_early_param+0x58/0x84 early_init_devtree+0xd4/0x518 early_setup+0xb4/0x214 So call jump_label_init() just before parse_early_param() in early_init_devtree(). Suggested-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Zhouyi Zhou <zhouzhouyi@gmail.com> [mpe: Add call trace to change log and minor wording edits.] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220726015747.11754-1-zhouzhouyi@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-25powerpc/pci: Fix get_phb_number() lockingMichael Ellerman
commit 8d48562a2729742f767b0fdd994d6b2a56a49c63 upstream. The recent change to get_phb_number() causes a DEBUG_ATOMIC_SLEEP warning on some systems: BUG: sleeping function called from invalid context at kernel/locking/mutex.c:580 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper preempt_count: 1, expected: 0 RCU nest depth: 0, expected: 0 1 lock held by swapper/1: #0: c157efb0 (hose_spinlock){+.+.}-{2:2}, at: pcibios_alloc_controller+0x64/0x220 Preemption disabled at: [<00000000>] 0x0 CPU: 0 PID: 1 Comm: swapper Not tainted 5.19.0-yocto-standard+ #1 Call Trace: [d101dc90] [c073b264] dump_stack_lvl+0x50/0x8c (unreliable) [d101dcb0] [c0093b70] __might_resched+0x258/0x2a8 [d101dcd0] [c0d3e634] __mutex_lock+0x6c/0x6ec [d101dd50] [c0a84174] of_alias_get_id+0x50/0xf4 [d101dd80] [c002ec78] pcibios_alloc_controller+0x1b8/0x220 [d101ddd0] [c140c9dc] pmac_pci_init+0x198/0x784 [d101de50] [c140852c] discover_phbs+0x30/0x4c [d101de60] [c0007fd4] do_one_initcall+0x94/0x344 [d101ded0] [c1403b40] kernel_init_freeable+0x1a8/0x22c [d101df10] [c00086e0] kernel_init+0x34/0x160 [d101df30] [c001b334] ret_from_kernel_thread+0x5c/0x64 This is because pcibios_alloc_controller() holds hose_spinlock but of_alias_get_id() takes of_mutex which can sleep. The hose_spinlock protects the phb_bitmap, and also the hose_list, but it doesn't need to be held while get_phb_number() calls the OF routines, because those are only looking up information in the device tree. So fix it by having get_phb_number() take the hose_spinlock itself, only where required, and then dropping the lock before returning. pcibios_alloc_controller() then needs to take the lock again before the list_add() but that's safe, the order of the list is not important. Fixes: 0fe1e96fef0a ("powerpc/pci: Prefer PCI domain assignment via DT 'linux,pci-domain' and alias") Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220815065550.1303620-1-mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-21powerpc/pci: Fix PHB numbering when using opal-phbidMichael Ellerman
[ Upstream commit f4b39e88b42d13366b831270306326b5c20971ca ] The recent change to the PHB numbering logic has a logic error in the handling of "ibm,opal-phbid". When an "ibm,opal-phbid" property is present, &prop is written to and ret is set to zero. The following call to of_alias_get_id() is skipped because ret == 0. But then the if (ret >= 0) is true, and the body of that if statement sets prop = ret which throws away the value that was just read from "ibm,opal-phbid". Fix the logic by only doing the ret >= 0 check in the of_alias_get_id() case. Fixes: 0fe1e96fef0a ("powerpc/pci: Prefer PCI domain assignment via DT 'linux,pci-domain' and alias") Reviewed-by: Pali Rohár <pali@kernel.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220802105723.1055178-1-mpe@ellerman.id.au Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-21powerpc/pci: Prefer PCI domain assignment via DT 'linux,pci-domain' and aliasPali Rohár
[ Upstream commit 0fe1e96fef0a5c53b4c0d1500d356f3906000f81 ] Other Linux architectures use DT property 'linux,pci-domain' for specifying fixed PCI domain of PCI controller specified in Device-Tree. And lot of Freescale powerpc boards have defined numbered pci alias in Device-Tree for every PCIe controller which number specify preferred PCI domain. So prefer usage of DT property 'linux,pci-domain' (via function of_get_pci_domain_nr()) and DT pci alias (via function of_alias_get_id()) on powerpc architecture for assigning PCI domain to PCI controller. Fixes: 63a72284b159 ("powerpc/pci: Assign fixed PHB number based on device-tree properties") Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220706102148.5060-2-pali@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>