linux-dev/arch/s390/lib/uaccess.c, branch linus/master

s390: convert ".insn" encoding to instruction names

2022-03-10T14:58:17Z

With z10 as minimum supported machine generation many ".insn" encodings could be now converted to instruction names. There are couple of exceptions - stfle is used from the als code built for z900 and cannot be converted - few ".insn" directives encode unsupported instruction formats The generated code is identical before/after this change. Acked-by: Ilya Leoshkevich Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390: raise minimum supported machine generation to z10

2022-03-10T14:58:17Z

Machine generations up to z9 (released in May 2006) have been officially out of service for several years now (z9 end of service - January 31, 2019). No distributions build kernels supporting those old machine generations anymore, except Debian, which seems to pick the oldest supported generation. The team supporting Debian on s390 has been notified about the change. Raising minimum supported machine generation to z10 helps to reduce maintenance cost and effectively remove code, which is not getting enough testing coverage due to lack of older hardware and distributions support. Besides that this unblocks some optimization opportunities and allows to use wider instruction set in asm files for future features implementation. Due to this change spectre mitigation and usercopy implementations could be drastically simplified and many newer instructions could be converted from ".insn" encoding to instruction names. Acked-by: Ilya Leoshkevich Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/uaccess: Add copy_from/to_user_key functions

2022-03-10T14:58:17Z

Add copy_from/to_user_key functions, which perform storage key checking. These functions can be used by KVM for emulating instructions that need to be key checked. These functions differ from their non _key counterparts in include/linux/uaccess.h only in the additional key argument and must be kept in sync with those. Since the existing uaccess implementation on s390 makes use of move instructions that support having an additional access key supplied, we can implement raw_copy_from/to_user_key by enhancing the existing implementation. Signed-off-by: Janis Schoetterl-Glausch Acked-by: Heiko Carstens Reviewed-by: Christian Borntraeger Acked-by: Janosch Frank Link: https://lore.kernel.org/r/20220211182215.2730017-2-scgl@linux.ibm.com Signed-off-by: Vasily Gorbik

s390/extable: move EX_TABLE define to asm-extable.h

2022-03-07T23:33:00Z

Follow arm64 and riscv and move the EX_TABLE define to asm-extable.h which is a lot less generic than the current linkage.h. Also make sure that all files which contain EX_TABLE usages actually include the new header file. This should make sure that the files always compile and there won't be any random compile breakage due to other header file dependencies. Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/uaccess: introduce bit field for OAC specifier

2022-01-17T13:13:09Z

Previously, we've used magic values to specify the OAC (operand-access control) for mvcos. Instead we introduce a bit field for it. When using a bit field, we cannot use an immediate value with K constraint anymore, since GCC older than 10 doesn't recognize the bit field union as a compile time constant. To make things work with older compilers, load the OAC value through a register. Bloat-o-meter reports a slight increase in kernel size with this change: Total: Before=15692135, After=15693015, chg +0.01% Signed-off-by: Nico Boehr Co-developed-by: Janis Schoetterl-Glausch Signed-off-by: Janis Schoetterl-Glausch Link: https://lore.kernel.org/r/20220111100003.743116-1-scgl@linux.ibm.com Cc: Alexander Gordeev Cc: Christian Borntraeger Cc: Vasily Gorbik Cc: Sven Schnelle Signed-off-by: Heiko Carstens

arch: remove compat_alloc_user_space

2021-09-08T22:32:35Z

All users of compat_alloc_user_space() and copy_in_user() have been removed from the kernel, only a few functions in sparc remain that can be changed to calling arch_copy_in_user() instead. Link: https://lkml.kernel.org/r/20210727144859.4150043-7-arnd@kernel.org Signed-off-by: Arnd Bergmann Reviewed-by: Christoph Hellwig Cc: Al Viro Cc: Benjamin Herrenschmidt Cc: Borislav Petkov Cc: Catalin Marinas Cc: Christian Borntraeger Cc: Christoph Hellwig Cc: "David S. Miller" Cc: Eric Biederman Cc: Feng Tang Cc: Heiko Carstens Cc: Helge Deller Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: "James E.J. Bottomley" Cc: Michael Ellerman Cc: Paul Mackerras Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Cc: Vasily Gorbik Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

s390: use generic strncpy/strnlen from_user

2021-07-27T21:01:13Z

The s390 variant of strncpy_from_user() is slightly faster than the generic variant, however convert to the generic variant now to follow most if not all other architectures. Converting to the generic variant was already considered a couple of years ago. See commit f5c8b9601036 ("s390/uaccess: use sane length for __strncpy_from_user()"). Signed-off-by: Heiko Carstens Signed-off-by: Arnd Bergmann

s390/lib,uaccess: fix copy_in_user_mvcos() inline asm clobber list

2021-07-05T10:44:23Z

General register 0 is clobbered within the inline assembly and therefore must be listed in the clobber list. Fixes: d1e18efa8fa9 ("s390/lib,uaccess: get rid of register asm") Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/lib,uaccess: get rid of register asm

2021-06-28T09:18:28Z

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

s390: convert to generic entry

2021-01-19T11:29:26Z

This patch converts s390 to use the generic entry infrastructure from kernel/entry/*. There are a few special things on s390: - PIF_PER_TRAP is moved to TIF_PER_TRAP as the generic code doesn't know about our PIF flags in exit_to_user_mode_loop(). - The old code had several ways to restart syscalls: a) PIF_SYSCALL_RESTART, which was only set during execve to force a restart after upgrading a process (usually qemu-kvm) to pgste page table extensions. b) PIF_SYSCALL, which is set by do_signal() to indicate that the current syscall should be restarted. This is changed so that do_signal() now also uses PIF_SYSCALL_RESTART. Continuing to use PIF_SYSCALL doesn't work with the generic code, and changing it to PIF_SYSCALL_RESTART makes PIF_SYSCALL and PIF_SYSCALL_RESTART more unique. - On s390 calling sys_sigreturn or sys_rt_sigreturn is implemented by executing a svc instruction on the process stack which causes a fault. While handling that fault the fault code sets PIF_SYSCALL to hand over processing to the syscall code on exit to usermode. The patch introduces PIF_SYSCALL_RET_SET, which is set if ptrace sets a return value for a syscall. The s390x ptrace ABI uses r2 both for the syscall number and return value, so ptrace cannot set the syscall number + return value at the same time. The flag makes handling that a bit easier. do_syscall() will just skip executing the syscall if PIF_SYSCALL_RET_SET is set. CONFIG_DEBUG_ASCE was removd in favour of the generic CONFIG_DEBUG_ENTRY. CR1/7/13 will be checked both on kernel entry and exit to contain the correct asces. Signed-off-by: Sven Schnelle Signed-off-by: Vasily Gorbik