kernel/linux.git/arch/powerpc, branch v6.12.108

powerpc/hv-gpci: fix preempt count leak in sysfs show paths

2026-09-02T12:30:58+00:00

[ Upstream commit dbc30a57bd8e026995e9fa8e8c31cffd18542c01 ] Four sysfs show() callbacks in hv-gpci take get_cpu_var(hv_gpci_reqb) (which calls preempt_disable()) but only call the matching put_cpu_var() on the error path under the 'out:' label. Every successful read leaks one preempt_disable(): processor_bus_topology_show() processor_config_show() affinity_domain_via_virtual_processor_show() affinity_domain_via_domain_show() (affinity_domain_via_partition_show() was already correct.) On a CONFIG_PREEMPT=y kernel, repeated reads raise preempt_count and eventually return to userspace with preemption still disabled. The next user-mode page fault then hits faulthandler_disabled() == 1, gets forced to SIGSEGV, and the resulting coredump trips 'BUG: scheduling while atomic' in call_usermodehelper_exec -> wait_for_completion_state -> schedule: BUG: scheduling while atomic: //0x00000004 ... __schedule_bug+0x6c/0x90 __schedule+0x58c/0x13a0 schedule+0x48/0x1a0 schedule_timeout+0x104/0x170 wait_for_completion_state+0x16c/0x330 call_usermodehelper_exec+0x254/0x2d0 vfs_coredump+0x1050/0x2590 get_signal+0xb9c/0xc80 do_notify_resume+0xf8/0x470 Add an out_success label that calls put_cpu_var() before returning the byte count, mirroring affinity_domain_via_partition_show(). Fixes: 71f1c39647d8 ("powerpc/hv_gpci: Add sysfs file inside hv_gpci device to show processor bus topology information") Fixes: 1a160c2a13c6 ("powerpc/hv_gpci: Add sysfs file inside hv_gpci device to show processor config information") Fixes: 71a7ccb478fc ("powerpc/hv_gpci: Add sysfs file inside hv_gpci device to show affinity domain via virtual processor information") Fixes: a69a57cac1ec ("powerpc/hv_gpci: Add sysfs file inside hv_gpci device to show affinity domain via domain information") Signed-off-by: Aboorva Devarajan Reviewed-by: Ritesh Harjani (IBM) Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260508041256.3447113-1-aboorvad@linux.ibm.com Signed-off-by: Sasha Levin

powerpc/pseries: lparcfg - fix kbuf[] underflow

2026-08-23T12:22:38+00:00

commit fb442a6673ff1046bf67754957d95880fdb394b5 upstream. In lparcfg_write(), a count of 0 results in kbuf[] being indexed at -1. Check for count == 0 in the existing check for count > sizeof(kbuf) and return -EINVAL if true. Fixes: 74422e2b1939 ("powerpc/pseries: Remove VLA from lparcfg_write()") Acked-by: Nayna Jain Tested-by: R Nageswara Sastry Cc: stable@vger.kernel.org # 4.20 Signed-off-by: George Wilson Signed-off-by: Madhavan Srinivasan Signed-off-by: Greg Kroah-Hartman

powerpc/pseries: pci - logic bug

2026-08-23T12:22:37+00:00

commit 649c10bff5cb7a514bf299094833ec8c9190aac3 upstream. The checks on num_vfs in pseries_pci_sriov_enable() are ANDed where OR was apparently intended. Change it to OR. Fixes: 9a7f6b438664 ("powerpc/pseries/pci: Associate PEs to VFs in configure SR-IOV") Acked-by: Nayna Jain Tested-by: R Nageswara Sastry Cc: stable@vger.kernel.org # 4.16 Signed-off-by: George Wilson Signed-off-by: Madhavan Srinivasan Signed-off-by: Greg Kroah-Hartman

powerpc/ps3: Fix map failure path in dma_ioc0_map_pages()

2026-08-09T18:23:15+00:00

commit 0bb024f11d120abff3e8db9144a585b9d7fb8459 upstream. If lv1_put_iopte() fails in dma_ioc0_map_pages(), the error path decrements iopage but keeps using the failed mapping's offset. As a result, it repeatedly tries to invalidate the failed IOPTE slot and leaves the already installed IOPTEs valid. Recompute offset and invalidate the installed IOPTEs instead. Fixes: 6bb5cf102541 ("[POWERPC] PS3: System-bus rework") Cc: stable@vger.kernel.org Signed-off-by: Thorsten Blum Reviewed-by: Ritesh Harjani (IBM) Reviewed-by: Geert Uytterhoeven Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260711130931.740719-3-thorsten.blum@linux.dev Signed-off-by: Greg Kroah-Hartman

powerpc/boot: Fix treeboot-akebono CPU node lookup check

2026-08-09T18:23:06+00:00

[ Upstream commit b24fc8278b70a9d27ec801a427ab4de9b769d69a ] fdt_node_offset_by_prop_value() returns a negative error code on failure - fix the check accordingly. Fixes: 2a2c74b2efcb ("IBM Akebono: Add the Akebono platform") Signed-off-by: Thorsten Blum Reviewed-by: Ritesh Harjani (IBM) Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260702211554.56923-6-thorsten.blum@linux.dev Signed-off-by: Sasha Levin

powerpc/boot: Fix treeboot-currituck CPU node lookup check

2026-08-09T18:23:06+00:00

[ Upstream commit 43863f6575d2211e8c5157fefb83ad0ad046aab4 ] fdt_node_offset_by_prop_value() returns a negative error code on failure - fix the check accordingly. Fixes: 228d55053397 ("powerpc/47x: Add support for the new IBM currituck platform") Signed-off-by: Thorsten Blum Reviewed-by: Ritesh Harjani (IBM) Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260702211554.56923-5-thorsten.blum@linux.dev Signed-off-by: Sasha Levin

powerpc/boot: Fix simpleboot CPU node lookup check

2026-08-09T18:23:06+00:00

[ Upstream commit c824ab65685bb119c6c6a3a200b3428c72862d5a ] fdt_node_offset_by_prop_value() returns a negative error code on failure - fix the check accordingly. Fixes: d2477b5cc8ca ("[POWERPC] bootwrapper: Add a firmware-independent simpleboot target.") Signed-off-by: Thorsten Blum Reviewed-by: Ritesh Harjani (IBM) Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260702211554.56923-4-thorsten.blum@linux.dev Signed-off-by: Sasha Levin

mm: prepare to move subsection_map_init() to mm/sparse-vmemmap.c

2026-08-03T09:17:34+00:00

[ Upstream commit fead6dcff83b02f8d6dc3c1ebbe4e09c05c54ee5 ] We want to move subsection_map_init() to mm/sparse-vmemmap.c. To prepare for getting rid of subsection_map_init() in mm/sparse.c completely, use a static inline function for !CONFIG_SPARSEMEM_VMEMMAP. While at it, move the declaration to internal.h and rename it to "sparse_init_subsection_map()". Link: https://lkml.kernel.org/r/20260320-sparsemem_cleanups-v2-11-096addc8800d@kernel.org Signed-off-by: David Hildenbrand (Arm) Reviewed-by: Lorenzo Stoakes (Oracle) Reviewed-by: Mike Rapoport (Microsoft) Cc: Axel Rasmussen Cc: Liam Howlett Cc: Michal Hocko Cc: Oscar Salvador Cc: Sidhartha Kumar Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Wei Xu Cc: Yuanchu Xie Signed-off-by: Andrew Morton Stable-dep-of: 721a73e30c9e ("mm/sparse-vmemmap: fix DAX vmemmap accounting with optimization") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

powerpc/vtime: Initialize starttime at boot for native accounting

2026-08-03T09:17:05+00:00

[ Upstream commit c1c1ffa490fc33591e90852ed0d38804dd20bc36 ] It was observed that /proc/stat had very large value for one ore more CPUs. It was more visible after recent code simplifications around cpustats. System has 240 CPUs. cat /proc/uptime; 194.18 46500.55 cat /proc/stat cpu 5966 39 837032887 4650070 164 185 100 0 0 0 cpu0 108 0 837030890 19109 24 4 23 0 0 0 Since uptime is 194s, system time of each CPU can't be more than 19400. Sum of system time of all CPUs can't be more than 19400*240 4656000. In fact huge value is close to mftb(). Note mftb doesn't reset on powerVM when the LPAR restart. It only resets when whole system resets. The same issue exists for kexec too. This happens since starttime is not setup at init time. Once it is set then subsequent vtime_delta will return the right delta. Fix it by initializing the starttime during CPU initialization. This fixes the large times seen. cat /proc/uptime; cat /proc/stat 15.78 3694.63 cpu 6035 35 1347 369479 23 144 49 0 0 0 cpu0 19 0 38 1508 0 1 14 0 0 0 Now, system time is reported as expected. Fixes: cf9efce0ce31 ("powerpc: Account time using timebase rather than PURR") Reviewed-by: Christophe Leroy (CS GROUP) Suggested-by: Christophe Leroy (CS GROUP) Signed-off-by: Shrikanth Hegde Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260605124329.377533-1-sshegde@linux.ibm.com Signed-off-by: Sasha Levin

powerpc/time: Prepare to stop elapsing in dynticks-idle

2026-08-03T09:17:05+00:00

[ Upstream commit c8ba971cf8567d49eb5f43ee90c4e50424331c18 ] Currently the tick subsystem stores the idle cputime accounting in private fields, allowing cohabitation with architecture idle vtime accounting. The former is fetched on online CPUs, the latter on offline CPUs. For consolidation purpose, architecture vtime accounting will continue to account the cputime but will make a break when the idle tick is stopped. The dyntick cputime accounting will then be relayed by the tick subsystem so that the idle cputime is still seen advancing coherently even when the tick isn't there to flush the idle vtime. Prepare for that and introduce three new APIs which will be used in subsequent patches: - vtime_dynticks_start() is deemed to be called when idle enters in dyntick mode. The idle cputime that elapsed so far is accumulated. - vtime_dynticks_stop() is deemed to be called when idle exits from dyntick mode. The vtime entry clocks are fast-forward to current time so that idle accounting restarts elapsing from now. - vtime_reset() is deemed to be called from dynticks idle IRQ entry to fast-forward the clock to current time so that the IRQ time is still accounted by vtime while nohz cputime is paused. Also accumulated vtime won't be flushed from dyntick-idle ticks to avoid accounting twice the idle cputime, along with nohz accounting. Signed-off-by: Frederic Weisbecker Signed-off-by: Thomas Gleixner Tested-by: Shrikanth Hegde Reviewed-by: Shrikanth Hegde Link: https://patch.msgid.link/20260508131647.43868-6-frederic@kernel.org Stable-dep-of: c1c1ffa490fc ("powerpc/vtime: Initialize starttime at boot for native accounting") Signed-off-by: Sasha Levin