kernel.git/arch/s390, branch linux-6.0.y

KVM: s390: vsie: Fix the initialization of the epoch extension (epdx) field

2022-12-14T10:40:53Z

commit 0dd4cdccdab3d74bd86b868768a7dca216bcce7e upstream. We recently experienced some weird huge time jumps in nested guests when rebooting them in certain cases. After adding some debug code to the epoch handling in vsie.c (thanks to David Hildenbrand for the idea!), it was obvious that the "epdx" field (the multi-epoch extension) did not get set to 0xff in case the "epoch" field was negative. Seems like the code misses to copy the value from the epdx field from the guest to the shadow control block. By doing so, the weird time jumps are gone in our scenarios. Link: https://bugzilla.redhat.com/show_bug.cgi?id=2140899 Fixes: 8fa1696ea781 ("KVM: s390: Multiple Epoch Facility support") Signed-off-by: Thomas Huth Reviewed-by: Christian Borntraeger Acked-by: David Hildenbrand Reviewed-by: Claudio Imbrenda Reviewed-by: Janosch Frank Cc: stable@vger.kernel.org # 4.19+ Link: https://lore.kernel.org/r/20221123090833.292938-1-thuth@redhat.com Message-Id: <20221123090833.292938-1-thuth@redhat.com> Signed-off-by: Janosch Frank Signed-off-by: Greg Kroah-Hartman

s390/crashdump: fix TOD programmable field size

2022-12-02T16:43:09Z

[ Upstream commit f44e07a8afdd713ddc1a8832c39372fe5dd86895 ] The size of the TOD programmable field was incorrectly increased from four to eight bytes with commit 1a2c5840acf9 ("s390/dump: cleanup CPU save area handling"). This leads to an elf notes section NT_S390_TODPREG which has a size of eight instead of four bytes in case of kdump, however even worse is that the contents is incorrect: it is supposed to contain only the contents of the TOD programmable field, but in fact contains a mix of the TOD programmable field (32 bit upper bits) and parts of the CPU timer register (lower 32 bits). Fix this by simply changing the size of the todpreg field within the save area structure. This will implicitly also fix the size of the corresponding elf notes sections. This also gets rid of this compile time warning: in function ‘fortify_memcpy_chk’, inlined from ‘save_area_add_regs’ at arch/s390/kernel/crash_dump.c:99:2: ./include/linux/fortify-string.h:413:25: error: call to ‘__read_overflow2_field’ declared with attribute warning: detected read beyond size of field (2nd parameter); maybe use struct_group()? [-Werror=attribute-warning] 413 | __read_overflow2_field(q_size_field, size); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Fixes: 1a2c5840acf9 ("s390/dump: cleanup CPU save area handling") Reviewed-by: Christian Borntraeger Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev Signed-off-by: Sasha Levin

s390: always build relocatable kernel

2022-12-02T16:43:01Z

[ Upstream commit 80ddf5ce1c9291cb175d52ed1227134ad48c47ee ] Nathan Chancellor reported several link errors on s390 with CONFIG_RELOCATABLE disabled, after binutils commit 906f69cf65da ("IBM zSystems: Issue error for *DBL relocs on misaligned symbols"). The binutils commit reveals potential miscompiles that might have happened already before with linker script defined symbols at odd addresses. A similar bug was recently fixed in the kernel with commit c9305b6c1f52 ("s390: fix nospec table alignments"). See https://github.com/ClangBuiltLinux/linux/issues/1747 for an analysis from Ulich Weigand. Therefore always build a relocatable kernel to avoid this problem. There is hardly any use-case for non-relocatable kernels, so this shouldn't be controversial. Link: https://github.com/ClangBuiltLinux/linux/issues/1747 Signed-off-by: Heiko Carstens Reported-by: Nathan Chancellor Tested-by: Nathan Chancellor Link: https://lore.kernel.org/r/20221030182202.2062705-1-hca@linux.ibm.com Signed-off-by: Alexander Gordeev Signed-off-by: Sasha Levin

s390: avoid using global register for current_stack_pointer

2022-11-26T08:27:39Z

[ Upstream commit e3c11025bcd2142a61abe5806b2f86a0e78118df ] Commit 30de14b1884b ("s390: current_stack_pointer shouldn't be a function") made current_stack_pointer a global register variable like on many other architectures. Unfortunately on s390 it uncovers old gcc bug which is fixed only since gcc-9.1 [gcc commit 3ad7fed1cc87 ("S/390: Fix PR89775. Stackpointer save/restore instructions removed")] and backported to gcc-8.4 and later. Due to this bug gcc versions prior to 8.4 generate broken code which leads to stack corruptions. Current minimal gcc version required to build the kernel is declared as 5.1. It is not possible to fix all old gcc versions, so work around this problem by avoiding using global register variable for current_stack_pointer. Fixes: 30de14b1884b ("s390: current_stack_pointer shouldn't be a function") Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Alexander Gordeev Signed-off-by: Sasha Levin

KVM: s390: pci: Fix allocation size of aift kzdev elements

2022-11-16T09:03:54Z

[ Upstream commit b6662e37772715447aeff2538444ff291e02ea31 ] The 'kzdev' field of struct 'zpci_aift' is an array of pointers to 'kvm_zdev' structs. Allocate the proper size accordingly. Reported by Coccinelle: WARNING: Use correct pointer type argument for sizeof Fixes: 98b1d33dac5f ("KVM: s390: pci: do initial setup for AEN interpretation") Signed-off-by: Rafael Mendonca Reviewed-by: Christian Borntraeger Reviewed-by: Matthew Rosato Link: https://lore.kernel.org/r/20221026013234.960859-1-rafaelmendsr@gmail.com Message-Id: <20221026013234.960859-1-rafaelmendsr@gmail.com> Signed-off-by: Janosch Frank Signed-off-by: Sasha Levin

KVM: s390: pv: don't allow userspace to set the clock under PV

2022-11-16T09:03:54Z

[ Upstream commit 6973091d1b50ab4042f6a2d495f59e9db3662ab8 ] When running under PV, the guest's TOD clock is under control of the ultravisor and the hypervisor isn't allowed to change it. Hence, don't allow userspace to change the guest's TOD clock by returning -EOPNOTSUPP. When userspace changes the guest's TOD clock, KVM updates its kvm.arch.epoch field and, in addition, the epoch field in all state descriptions of all VCPUs. But, under PV, the ultravisor will ignore the epoch field in the state description and simply overwrite it on next SIE exit with the actual guest epoch. This leads to KVM having an incorrect view of the guest's TOD clock: it has updated its internal kvm.arch.epoch field, but the ultravisor ignores the field in the state description. Whenever a guest is now waiting for a clock comparator, KVM will incorrectly calculate the time when the guest should wake up, possibly causing the guest to sleep for much longer than expected. With this change, kvm_s390_set_tod() will now take the kvm->lock to be able to call kvm_s390_pv_is_protected(). Since kvm_s390_set_tod_clock() also takes kvm->lock, use __kvm_s390_set_tod_clock() instead. The function kvm_s390_set_tod_clock is now unused, hence remove it. Update the documentation to indicate the TOD clock attr calls can now return -EOPNOTSUPP. Fixes: 0f3035047140 ("KVM: s390: protvirt: Do only reset registers that are accessible") Reported-by: Marc Hartmayer Signed-off-by: Nico Boehr Reviewed-by: Claudio Imbrenda Reviewed-by: Janosch Frank Link: https://lore.kernel.org/r/20221011160712.928239-2-nrb@linux.ibm.com Message-Id: <20221011160712.928239-2-nrb@linux.ibm.com> Signed-off-by: Janosch Frank Signed-off-by: Sasha Levin

s390/pci: add missing EX_TABLE entries to __pcistg_mio_inuser()/__pcilg_mio_inuser()

2022-11-03T15:00:24Z

commit 6ec803025cf3173a57222e4411097166bd06fa98 upstream. For some exception types the instruction address points behind the instruction that caused the exception. Take that into account and add the missing exception table entry. Cc: Fixes: f058599e22d5 ("s390/pci: Fix s390_mmio_read/write with MIO") Reviewed-by: Niklas Schnelle Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman

s390/futex: add missing EX_TABLE entry to __futex_atomic_op()

2022-11-03T15:00:24Z

commit a262d3ad6a433e4080cecd0a8841104a5906355e upstream. For some exception types the instruction address points behind the instruction that caused the exception. Take that into account and add the missing exception table entry. Cc: Reviewed-by: Vasily Gorbik Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman

s390/uaccess: add missing EX_TABLE entries to __clear_user()

2022-11-03T15:00:24Z

commit 4e1b5a86a5edfbefc9396d41b0fc1a2ebd0101b6 upstream. For some exception types the instruction address points behind the instruction that caused the exception. Take that into account and add the missing exception table entries. Cc: Reviewed-by: Vasily Gorbik Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman

s390/boot: add secure boot trailer

2022-11-03T15:00:24Z

commit aa127a069ef312aca02b730d5137e1778d0c3ba7 upstream. This patch enhances the kernel image adding a trailer as required for secure boot by future firmware versions. Cc: # 5.2+ Signed-off-by: Peter Oberparleiter Reviewed-by: Sven Schnelle Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman