kernel.git/arch/s390, branch linux-4.16.y

KVM: s390: vsie: fix < 8k check for the itdba

2018-05-30T06:17:18Z

commit f4a551b72358facbbe5714248dff78404272feee upstream. By missing an "L", we might detect some addresses to be <8k, although they are not. e.g. for itdba = 100001fff !(gpa & ~0x1fffU) -> 1 !(gpa & ~0x1fffUL) -> 0 So we would report a SIE validity intercept although everything is fine. Fixes: 166ecb3 ("KVM: s390: vsie: support transactional execution") Reported-by: Dan Carpenter Reviewed-by: Christian Borntraeger Reviewed-by: Janosch Frank Reviewed-by: Cornelia Huck Signed-off-by: David Hildenbrand Signed-off-by: Janosch Frank Cc: stable@vger.kernel.org # v4.8+ Signed-off-by: Christian Borntraeger Signed-off-by: Greg Kroah-Hartman

s390: use expoline thunks in the BPF JIT

2018-05-25T14:46:08Z

[ Upstream commit de5cb6eb514ebe241e3edeb290cb41deb380b81d ] The BPF JIT need safe guarding against spectre v2 in the sk_load_xxx assembler stubs and the indirect branches generated by the JIT itself need to be converted to expolines. Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman

s390: extend expoline to BC instructions

2018-05-25T14:46:08Z

[ Upstream commit 6deaa3bbca804b2a3627fd685f75de64da7be535 ] The BPF JIT uses a 'b (%r)' instruction in the definition of the sk_load_word and sk_load_half functions. Add support for branch-on-condition instructions contained in the thunk code of an expoline. Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman

s390: move spectre sysfs attribute code

2018-05-25T14:46:07Z

[ Upstream commit 4253b0e0627ee3461e64c2495c616f1c8f6b127b ] The nospec-branch.c file is compiled without the gcc options to generate expoline thunks. The return branch of the sysfs show functions cpu_show_spectre_v1 and cpu_show_spectre_v2 is an indirect branch as well. These need to be compiled with expolines. Move the sysfs functions for spectre reporting to a separate file and loose an '.' for one of the messages. Cc: stable@vger.kernel.org # 4.16 Fixes: d424986f1d ("s390: add sysfs attributes for spectre") Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman

s390/kernel: use expoline for indirect branches

2018-05-25T14:46:07Z

[ Upstream commit c50c84c3ac4d5db683904bdb3257798b6ef980ae ] The assember code in arch/s390/kernel uses a few more indirect branches which need to be done with execute trampolines for CONFIG_EXPOLINE=y. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Reviewed-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman

s390/ftrace: use expoline for indirect branches

2018-05-25T14:46:07Z

[ Upstream commit 23a4d7fd34856da8218c4cfc23dba7a6ec0a423a ] The return from the ftrace_stub, _mcount, ftrace_caller and return_to_handler functions is done with "br %r14" and "br %r1". These are indirect branches as well and need to use execute trampolines for CONFIG_EXPOLINE=y. The ftrace_caller function is a special case as it returns to the start of a function and may only use %r0 and %r1. For a pre z10 machine the standard execute trampoline uses a LARL + EX to do this, but this requires *two* registers in the range %r1..%r15. To get around this the 'br %r1' located in the lowcore is used, then the EX instruction does not need an address register. But the lowcore trick may only be used for pre z14 machines, with noexec=on the mapping for the first page may not contain instructions. The solution for that is an ALTERNATIVE in the expoline THUNK generated by 'GEN_BR_THUNK %r1' to switch to EXRL, this relies on the fact that a machine that supports noexec=on has EXRL as well. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman

s390/lib: use expoline for indirect branches

2018-05-25T14:46:07Z

[ Upstream commit 97489e0663fa700d6e7febddc43b58df98d7bcda ] The return from the memmove, memset, memcpy, __memset16, __memset32 and __memset64 functions are done with "br %r14". These are indirect branches as well and need to use execute trampolines for CONFIG_EXPOLINE=y. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Reviewed-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman

s390/crc32-vx: use expoline for indirect branches

2018-05-25T14:46:07Z

[ Upstream commit 467a3bf219cee12259182c5cb4821f88fd518a51 ] The return from the crc32_le_vgfm_16/crc32c_le_vgfm_16 and the crc32_be_vgfm_16 functions are done with "br %r14". These are indirect branches as well and need to use execute trampolines for CONFIG_EXPOLINE=y. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Reviewed-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman

s390: move expoline assembler macros to a header

2018-05-25T14:46:07Z

[ Upstream commit 6dd85fbb87d1d6b87a3b1f02ca28d7b2abd2e7ba ] To be able to use the expoline branches in different assembler files move the associated macros from entry.S to a new header nospec-insn.h. While we are at it make the macros a bit nicer to use. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman

s390: correct module section names for expoline code revert

2018-05-25T14:46:07Z

[ Upstream commit 6cf09958f32b9667bb3ebadf74367c791112771b ] The main linker script vmlinux.lds.S for the kernel image merges the expoline code patch tables into two section ".nospec_call_table" and ".nospec_return_table". This is *not* done for the modules, there the sections retain their original names as generated by gcc: ".s390_indirect_call", ".s390_return_mem" and ".s390_return_reg". The module_finalize code has to check for the compiler generated section names, otherwise no code patching is done. This slows down the module code in case of "spectre_v2=off". Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman