kernel/linux.git/arch/s390/include, branch v6.12.80

s390/barrier: Make array_index_mask_nospec() __always_inline

2026-04-02T11:09:41+00:00

commit c5c0a268b38adffbb2e70e6957017537ff54c157 upstream. Mark array_index_mask_nospec() as __always_inline to guarantee the mitigation is emitted inline regardless of compiler inlining decisions. Fixes: e2dd833389cc ("s390: add optimized array_index_mask_nospec") Cc: stable@kernel.org Reviewed-by: Ilya Leoshkevich Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman

s390/stackleak: Fix __stackleak_poison() inline assembly constraint

2026-03-25T10:08:46+00:00

commit 674c5ff0f440a051ebf299d29a4c013133d81a65 upstream. The __stackleak_poison() inline assembly comes with a "count" operand where the "d" constraint is used. "count" is used with the exrl instruction and "d" means that the compiler may allocate any register from 0 to 15. If the compiler would allocate register 0 then the exrl instruction would not or the value of "count" into the executed instruction - resulting in a stackframe which is only partially poisoned. Use the correct "a" constraint, which excludes register 0 from register allocation. Fixes: 2a405f6bb3a5 ("s390/stackleak: provide fast __stackleak_poison() implementation") Cc: stable@vger.kernel.org Signed-off-by: Heiko Carstens Reviewed-by: Vasily Gorbik Link: https://lore.kernel.org/r/20260302133500.1560531-4-hca@linux.ibm.com Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman

s390/idle: Fix cpu idle exit cpu time accounting

2026-03-13T16:20:18+00:00

[ Upstream commit 0d785e2c324c90662baa4fe07a0d02233ff92824 ] With the conversion to generic entry [1] cpu idle exit cpu time accounting was converted from assembly to C. This introduced an reversed order of cpu time accounting. On cpu idle exit the current accounting happens with the following call chain: -> do_io_irq()/do_ext_irq() -> irq_enter_rcu() -> account_hardirq_enter() -> vtime_account_irq() -> vtime_account_kernel() vtime_account_kernel() accounts the passed cpu time since last_update_timer as system time, and updates last_update_timer to the current cpu timer value. However the subsequent call of -> account_idle_time_irq() will incorrectly subtract passed cpu time from timer_idle_enter to the updated last_update_timer value from system_timer. Then last_update_timer is updated to a sys_enter_timer, which means that last_update_timer goes back in time. Subsequently account_hardirq_exit() will account too much cpu time as hardirq time. The sum of all accounted cpu times is still correct, however some cpu time which was previously accounted as system time is now accounted as hardirq time, plus there is the oddity that last_update_timer goes back in time. Restore previous behavior by extracting cpu time accounting code from account_idle_time_irq() into a new update_timer_idle() function and call it before irq_enter_rcu(). Fixes: 56e62a737028 ("s390: convert to generic entry") [1] Reviewed-by: Sven Schnelle Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin

tracing: Add ftrace_fill_perf_regs() for perf event

2026-03-04T12:19:37+00:00

[ Upstream commit d5d01b71996ec03af51b3c0736c92d0fc89703b5 ] Add ftrace_fill_perf_regs() which should be compatible with the perf_fetch_caller_regs(). In other words, the pt_regs returned from the ftrace_fill_perf_regs() must satisfy 'user_mode(regs) == false' and can be used for stack tracing. Signed-off-by: Masami Hiramatsu (Google) Acked-by: Will Deacon Acked-by: Heiko Carstens # s390 Cc: Alexei Starovoitov Cc: Florent Revest Cc: Martin KaFai Lau Cc: bpf Cc: Alexei Starovoitov Cc: Jiri Olsa Cc: Alan Maguire Cc: Heiko Carstens Cc: Mark Rutland Cc: Catalin Marinas Cc: Will Deacon Cc: Michael Ellerman Cc: Nicholas Piggin Cc: Christophe Leroy Cc: Naveen N Rao Cc: Madhavan Srinivasan Cc: Vasily Gorbik Cc: Alexander Gordeev Cc: Christian Borntraeger Cc: Sven Schnelle Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: x86@kernel.org Cc: "H. Peter Anvin" Link: https://lore.kernel.org/173518997908.391279.15910334347345106424.stgit@devnote2 Signed-off-by: Steven Rostedt (Google) Stable-dep-of: aea251799998 ("x86/fgraph,bpf: Switch kprobe_multi program stack unwind to hw_regs path") Signed-off-by: Sasha Levin

fgraph: Replace fgraph_ret_regs with ftrace_regs

2026-03-04T12:19:36+00:00

[ Upstream commit a3ed4157b7d89800a0008de0c9e46a438a5c3745 ] Use ftrace_regs instead of fgraph_ret_regs for tracing return value on function_graph tracer because of simplifying the callback interface. The CONFIG_HAVE_FUNCTION_GRAPH_RETVAL is also replaced by CONFIG_HAVE_FUNCTION_GRAPH_FREGS. Signed-off-by: Masami Hiramatsu (Google) Acked-by: Heiko Carstens Acked-by: Will Deacon Cc: Catalin Marinas Cc: Alexei Starovoitov Cc: Florent Revest Cc: Martin KaFai Lau Cc: bpf Cc: Alexei Starovoitov Cc: Jiri Olsa Cc: Alan Maguire Cc: Mark Rutland Cc: Huacai Chen Cc: WANG Xuerui Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Vasily Gorbik Cc: Alexander Gordeev Cc: Heiko Carstens Cc: Christian Borntraeger Cc: Sven Schnelle Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: x86@kernel.org Cc: "H. Peter Anvin" Cc: Mathieu Desnoyers Link: https://lore.kernel.org/173518991508.391279.16635322774382197642.stgit@devnote2 Signed-off-by: Steven Rostedt (Google) Stable-dep-of: aea251799998 ("x86/fgraph,bpf: Switch kprobe_multi program stack unwind to hw_regs path") Signed-off-by: Sasha Levin

ftrace: Consolidate ftrace_regs accessor functions for archs using pt_regs

2026-03-04T12:19:36+00:00

[ Upstream commit e4cf33ca48128d580e25ebe779b7ba7b4b4cf733 ] Most architectures use pt_regs within ftrace_regs making a lot of the accessor functions just calls to the pt_regs internally. Instead of duplication this effort, use a HAVE_ARCH_FTRACE_REGS for architectures that have their own ftrace_regs that is not based on pt_regs and will define all the accessor functions, and for the architectures that just use pt_regs, it will leave it undefined, and the default accessor functions will be used. Note, this will also make it easier to add new accessor functions to ftrace_regs as it will mean having to touch less architectures. Cc: Cc: "x86@kernel.org" Cc: Mathieu Desnoyers Cc: Mark Rutland Cc: Will Deacon Cc: Huacai Chen Cc: WANG Xuerui Cc: Michael Ellerman Cc: Nicholas Piggin Cc: Christophe Leroy Cc: Naveen N Rao Cc: Madhavan Srinivasan Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Alexander Gordeev Cc: Christian Borntraeger Cc: Sven Schnelle Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Link: https://lore.kernel.org/20241010202114.2289f6fd@gandalf.local.home Acked-by: Masami Hiramatsu (Google) Acked-by: Heiko Carstens # s390 Acked-by: Catalin Marinas Acked-by: Michael Ellerman # powerpc Suggested-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google) Stable-dep-of: aea251799998 ("x86/fgraph,bpf: Switch kprobe_multi program stack unwind to hw_regs path") Signed-off-by: Sasha Levin

ftrace: Make ftrace_regs abstract from direct use

2026-03-04T12:19:36+00:00

[ Upstream commit 7888af4166d4ab07ba51234be6ba332b7807e901 ] ftrace_regs was created to hold registers that store information to save function parameters, return value and stack. Since it is a subset of pt_regs, it should only be used by its accessor functions. But because pt_regs can easily be taken from ftrace_regs (on most archs), it is tempting to use it directly. But when running on other architectures, it may fail to build or worse, build but crash the kernel! Instead, make struct ftrace_regs an empty structure and have the architectures define __arch_ftrace_regs and all the accessor functions will typecast to it to get to the actual fields. This will help avoid usage of ftrace_regs directly. Link: https://lore.kernel.org/all/20241007171027.629bdafd@gandalf.local.home/ Cc: "linux-arch@vger.kernel.org" Cc: "x86@kernel.org" Cc: Mathieu Desnoyers Cc: Mark Rutland Cc: Will Deacon Cc: Huacai Chen Cc: WANG Xuerui Cc: Michael Ellerman Cc: Nicholas Piggin Cc: Christophe Leroy Cc: Naveen N Rao Cc: Madhavan Srinivasan Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Alexander Gordeev Cc: Christian Borntraeger Cc: Sven Schnelle Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Link: https://lore.kernel.org/20241008230628.958778821@goodmis.org Acked-by: Catalin Marinas Signed-off-by: Steven Rostedt (Google) Acked-by: Masami Hiramatsu (Google) Acked-by: Heiko Carstens # s390 Signed-off-by: Steven Rostedt (Google) Stable-dep-of: aea251799998 ("x86/fgraph,bpf: Switch kprobe_multi program stack unwind to hw_regs path") Signed-off-by: Sasha Levin

s390/ipl: Clear SBP flag when bootprog is set

2026-01-08T09:14:25+00:00

commit b1aa01d31249bd116b18c7f512d3e46b4b4ad83b upstream. With z16 a new flag 'search boot program' was introduced for list-directed IPL (SCSI, NVMe, ECKD DASD). If this flag is set, e.g. via selecting the "Automatic" value for the "Boot program selector" control on an HMC load panel, it is copied to the reipl structure from the initial ipl structure. When a user now sets a boot prog via sysfs, the flag is not cleared and the bootloader will again automatically select the boot program, ignoring user configuration. To avoid that, clear the SBP flag when a bootprog sysfs file is written. Cc: stable@vger.kernel.org Reviewed-by: Peter Oberparleiter Reviewed-by: Heiko Carstens Signed-off-by: Sven Schnelle Signed-off-by: Heiko Carstens Signed-off-by: Greg Kroah-Hartman

s390/mm: Fix __ptep_rdp() inline assembly

2025-12-01T10:43:37+00:00

[ Upstream commit 31475b88110c4725b4f9a79c3a0d9bbf97e69e1c ] When a zero ASCE is passed to the __ptep_rdp() inline assembly, the generated instruction should have the R3 field of the instruction set to zero. However the inline assembly is written incorrectly: for such cases a zero is loaded into a register allocated by the compiler and this register is then used by the instruction. This means that selected TLB entries may not be flushed since the specified ASCE does not match the one which was used when the selected TLB entries were created. Fix this by removing the asce and opt parameters of __ptep_rdp(), since all callers always pass zero, and use a hard-coded register zero for the R3 field. Fixes: 0807b856521f ("s390/mm: add support for RDP (Reset DAT-Protection)") Cc: stable@vger.kernel.org Reviewed-by: Gerald Schaefer Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin

s390/pci: Restore IRQ unconditionally for the zPCI device

2025-11-13T20:33:56+00:00

commit b45873c3f09153d1ad9b3a7bf9e5c0b0387fd2ea upstream. Commit c1e18c17bda6 ("s390/pci: add zpci_set_irq()/zpci_clear_irq()"), introduced the zpci_set_irq() and zpci_clear_irq(), to be used while resetting a zPCI device. Commit da995d538d3a ("s390/pci: implement reset_slot for hotplug slot"), mentions zpci_clear_irq() being called in the path for zpci_hot_reset_device(). But that is not the case anymore and these functions are not called outside of this file. Instead zpci_hot_reset_device() relies on zpci_disable_device() also clearing the IRQs, but misses to reset the zdev->irqs_registered flag. However after a CLP disable/enable reset, the device's IRQ are unregistered, but the flag zdev->irq_registered does not get cleared. It creates an inconsistent state and so arch_restore_msi_irqs() doesn't correctly restore the device's IRQ. This becomes a problem when a PCI driver tries to restore the state of the device through pci_restore_state(). Restore IRQ unconditionally for the device and remove the irq_registered flag as its redundant. Fixes: c1e18c17bda6 ("s390/pci: add zpci_set_irq()/zpci_clear_irq()") Cc: stable@vger.kernnel.org Reviewed-by: Niklas Schnelle Reviewed-by: Matthew Rosato Signed-off-by: Farhan Ali Signed-off-by: Heiko Carstens Signed-off-by: Greg Kroah-Hartman