linux-dev/arch/s390/kernel/vdso64, branch master

s390/vdso: filter out -mstack-guard and -mstack-size

2021-11-16T11:29:19Z

When CONFIG_VMAP_STACK is disabled, the user can enable CONFIG_STACK_CHECK, which adds a stack overflow check to each C function in the kernel. This is also done for functions in the vdso page. These functions are run in user context and user stack sizes are usually different to what the kernel uses. This might trigger the stack check although the stack size is valid. Therefore filter the -mstack-guard and -mstack-size flags when compiling vdso C files. Cc: stable@kernel.org # 5.10+ Fixes: 4bff8cb54502 ("s390: convert to GENERIC_VDSO") Reported-by: Janosch Frank Signed-off-by: Sven Schnelle Reviewed-by: Heiko Carstens Signed-off-by: Heiko Carstens

s390/vdso: remove -nostdlib compiler flag

2021-11-16T11:29:19Z

The -nostdlib option requests the compiler to not use the standard system startup files or libraries when linking. It is effective only when $(CC) is used as a linker driver. Since commit 2b2a25845d53 ("s390/vdso: Use $(LD) instead of $(CC) to link vDSO"), $(LD) is directly used, hence -nostdlib is unneeded. Signed-off-by: Masahiro Yamada Link: https://lore.kernel.org/r/20211107162111.323701-1-masahiroy@kernel.org Signed-off-by: Heiko Carstens

Merge tag 's390-5.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2021-08-30T20:07:15Z

Pull s390 updates from Heiko Carstens: - Improve ftrace code patching so that stop_machine is not required anymore. This requires a small common code patch acked by Steven Rostedt: https://lore.kernel.org/linux-s390/20210730220741.4da6fdf6@oasis.local.home/ - Enable KCSAN for s390. This comes with a small common code change to fix a compile warning. Acked by Marco Elver: https://lore.kernel.org/r/20210729142811.1309391-1-hca@linux.ibm.com - Add KFENCE support for s390. This also comes with a minimal x86 patch from Marco Elver who said also this can be carried via the s390 tree: https://lore.kernel.org/linux-s390/YQJdarx6XSUQ1tFZ@elver.google.com/ - More changes to prepare the decompressor for relocation. - Enable DAT also for CPU restart path. - Final set of register asm removal patches; leaving only three locations where needed and sane. - Add NNPA, Vector-Packed-Decimal-Enhancement Facility 2, PCI MIO support to hwcaps flags. - Cleanup hwcaps implementation. - Add new instructions to in-kernel disassembler. - Various QDIO cleanups. - Add SCLP debug feature. - Various other cleanups and improvements all over the place. * tag 's390-5.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (105 commits) s390: remove SCHED_CORE from defconfigs s390/smp: do not use nodat_stack for secondary CPU start s390/smp: enable DAT before CPU restart callback is called s390: update defconfigs s390/ap: fix state machine hang after failure to enable irq KVM: s390: generate kvm hypercall functions s390/sclp: add tracing of SCLP interactions s390/debug: add early tracing support s390/debug: fix debug area life cycle s390/debug: keep debug data on resize s390/diag: make restart_part2 a local label s390/mm,pageattr: fix walk_pte_level() early exit s390: fix typo in linker script s390: remove do_signal() prototype and do_notify_resume() function s390/crypto: fix all kernel-doc warnings in vfio_ap_ops.c s390/pci: improve DMA translation init and exit s390/pci: simplify CLP List PCI handling s390/pci: handle FH state mismatch only on disable s390/pci: fix misleading rc in clp_set_pci_fn() s390/boot: factor out offset_vmlinux_info() function ...

s390: enable KCSAN

2021-07-30T15:09:23Z

s390x GCC and SystemZ Clang have ThreadSanitizer support now [1] [2], so enable KCSAN for s390. [1] https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=ea22954e7c58 [2] https://reviews.llvm.org/D105629 Signed-off-by: Ilya Leoshkevich Signed-off-by: Heiko Carstens

s390/vdso: add .got.plt in vdso linker script

2021-07-30T15:08:21Z

KCFLAGS="-mno-pic-data-is-text-relative" make leads to bfd assertion error in s390_got_pointer(): LD arch/s390/kernel/vdso64/vdso64.so.dbg ld: BFD version 2.35-18.fc33 assertion fail elf-s390-common.c:74 readelf -Wr vdso64_generic.o | grep GOT 0000000000000032 000000110000001a R_390_GOTENT 0000000000000000 _vdso_data + 2 (...) Add .got.plt in linker script to avoid this. Suggested-by: Ilya Leoshkevich Signed-off-by: Sumanth Korikkar Signed-off-by: Heiko Carstens

s390/vdso: add minimal compat vdso

2021-07-08T13:37:28Z

Add a small vdso for 31 bit compat application that provides trampolines for calls to sigreturn,rt_sigreturn,syscall_restart. This is requird for moving these syscalls away from the signal frame to the vdso. Note that this patch effectively disables CONFIG_COMPAT when using clang to compile the kernel. clang doesn't support 31 bit mode. We want to redirect sigreturn and restart_syscall to the vdso. However, the kernel cannot parse the ELF vdso file, so we need to generate header files which contain the offsets of the syscall instructions in the vdso page. Signed-off-by: Sven Schnelle Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/vdso: rename VDSO64_LBASE to VDSO_LBASE

2021-07-08T13:37:28Z

Will be used by both vdso32 and vdso64, so change the name. Signed-off-by: Sven Schnelle Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/vdso64: add sigreturn,rt_sigreturn and restart_syscall

2021-07-08T13:37:28Z

Add minimalistic trampolines to vdso64 so we can return from signal without using the stack which requires pgm check handler hacks when NX is enabled. restart_syscall will be called from vdso to work around the architectural limitation that the syscall number might be encoded in the svc instruction, and therefore can not be changed. Signed-off-by: Sven Schnelle Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/vdso: use union tod_clock

2021-02-13T16:17:54Z

Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/vdso: implement generic vdso time namespace support

2021-02-09T14:57:05Z

Implement generic vdso time namespace support which also enables time namespaces for s390. This is quite similar to what arm64 has. Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik