kernel/linux.git/arch/s390/include, branch v5.15.208

s390/barrier: Make array_index_mask_nospec() __always_inline

2026-04-18T08:33:27+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/time: Use monotonic clock in get_cycles()

2025-08-28T14:24:20+00:00

[ Upstream commit 09e7e29d2b49ba84bcefb3dc1657726d2de5bb24 ] Otherwise the code might not work correctly when the clock is changed. Signed-off-by: Sven Schnelle Reviewed-by: Heiko Carstens Signed-off-by: Alexander Gordeev Signed-off-by: Sasha Levin

sched: Add wrapper for get_wchan() to keep task blocked

2025-08-28T14:24:03+00:00

commit 42a20f86dc19f9282d974df0ba4d226c865ab9dd upstream. Having a stable wchan means the process must be blocked and for it to stay that way while performing stack unwinding. Suggested-by: Peter Zijlstra Signed-off-by: Kees Cook Signed-off-by: Peter Zijlstra (Intel) Acked-by: Geert Uytterhoeven Acked-by: Russell King (Oracle) [arm] Tested-by: Mark Rutland [arm64] Link: https://lkml.kernel.org/r/20211008111626.332092234@infradead.org Signed-off-by: Siddhi Katage Signed-off-by: Greg Kroah-Hartman

s390/futex: Fix FUTEX_OP_ANDN implementation

2025-03-13T11:50:23+00:00

commit 26701574cee6777f867f89b4a5c667817e1ee0dd upstream. The futex operation FUTEX_OP_ANDN is supposed to implement *(int *)UADDR2 &= ~OPARG; The s390 implementation just implements an AND instead of ANDN. Add the missing bitwise not operation to oparg to fix this. This is broken since nearly 19 years, so it looks like user space is not making use of this operation. Fixes: 3363fbdd6fb4 ("[PATCH] s390: futex atomic operations") Cc: stable@vger.kernel.org Signed-off-by: Heiko Carstens Acked-by: Alexander Gordeev Signed-off-by: Alexander Gordeev Signed-off-by: Greg Kroah-Hartman

s390: Initialize psw mask in perf_arch_fetch_caller_regs()

2024-11-01T00:52:34+00:00

[ Upstream commit 223e7fb979fa06934f1595b6ad0ae1d4ead1147f ] Also initialize regs->psw.mask in perf_arch_fetch_caller_regs(). This way user_mode(regs) will return false, like it should. It looks like all current users initialize regs to zero, so that this doesn't fix a bug currently. However it is better to not rely on callers to do this. Fixes: 914d52e46490 ("s390: implement perf_arch_fetch_caller_regs") Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin

s390/facility: Disable compile time optimization for decompressor code

2024-10-17T13:11:49+00:00

[ Upstream commit 0147addc4fb72a39448b8873d8acdf3a0f29aa65 ] Disable compile time optimizations of test_facility() for the decompressor. The decompressor should not contain any optimized code depending on the architecture level set the kernel image is compiled for to avoid unexpected operation exceptions. Add a __DECOMPRESSOR check to test_facility() to enforce that facilities are always checked during runtime for the decompressor. Reviewed-by: Sven Schnelle Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin

s390/uv: Panic for set and remove shared access UVC errors

2024-09-04T11:23:17+00:00

[ Upstream commit cff59d8631e1409ffdd22d9d717e15810181b32c ] The return value uv_set_shared() and uv_remove_shared() (which are wrappers around the share() function) is not always checked. The system integrity of a protected guest depends on the Share and Unshare UVCs being successful. This means that any caller that fails to check the return value will compromise the security of the protected guest. No code path that would lead to such violation of the security guarantees is currently exercised, since all the areas that are shared never get unshared during the lifetime of the system. This might change and become an issue in the future. The Share and Unshare UVCs can only fail in case of hypervisor misbehaviour (either a bug or malicious behaviour). In such cases there is no reasonable way forward, and the system needs to panic. This patch replaces the return at the end of the share() function with a panic, to guarantee system integrity. Fixes: 5abb9351dfd9 ("s390/uv: introduce guest side ultravisor code") Signed-off-by: Claudio Imbrenda Reviewed-by: Christian Borntraeger Reviewed-by: Steffen Eiden Reviewed-by: Janosch Frank Link: https://lore.kernel.org/r/20240801112548.85303-1-imbrenda@linux.ibm.com Message-ID: <20240801112548.85303-1-imbrenda@linux.ibm.com> [frankja@linux.ibm.com: Fixed up patch subject] Signed-off-by: Janosch Frank Signed-off-by: Sasha Levin

s390: Mark psw in __load_psw_mask() as __unitialized

2024-07-18T11:07:38+00:00

[ Upstream commit 7278a8fb8d032dfdc03d9b5d17e0bc451cdc1492 ] Without __unitialized, the following code is generated when INIT_STACK_ALL_ZERO is enabled: 86: d7 0f f0 a0 f0 a0 xc 160(16,%r15), 160(%r15) 8c: e3 40 f0 a0 00 24 stg %r4, 160(%r15) 92: c0 10 00 00 00 08 larl %r1, 0xa2 98: e3 10 f0 a8 00 24 stg %r1, 168(%r15) 9e: b2 b2 f0 a0 lpswe 160(%r15) The xc is not adding any security because psw is fully initialized with the following instructions. Add __unitialized to the psw definitiation to avoid the superfluous clearing of psw. Reviewed-by: Heiko Carstens Signed-off-by: Sven Schnelle Signed-off-by: Alexander Gordeev Signed-off-by: Sasha Levin

KVM: s390: fix LPSWEY handling

2024-07-18T11:07:30+00:00

[ Upstream commit 4c6abb7f7b349f00c0f7ed5045bf67759c012892 ] in rare cases, e.g. for injecting a machine check we do intercept all load PSW instructions via ICTL_LPSW. With facility 193 a new variant LPSWEY was added. KVM needs to handle that as well. Fixes: a3efa8429266 ("KVM: s390: gen_facilities: allow facilities 165, 193, 194 and 196") Reported-by: Marc Hartmayer Reviewed-by: Sven Schnelle Reviewed-by: Claudio Imbrenda Signed-off-by: Christian Borntraeger Message-ID: <20240628163547.2314-1-borntraeger@linux.ibm.com> Signed-off-by: Sasha Levin

s390/cpacf: Make use of invalid opcode produce a link error

2024-06-16T11:40:00+00:00

commit 32e8bd6423fc127d2b37bdcf804fd76af3bbec79 upstream. Instead of calling BUG() at runtime introduce and use a prototype for a non-existing function to produce a link error during compile when a not supported opcode is used with the __cpacf_query() or __cpacf_check_opcode() inline functions. Suggested-by: Heiko Carstens Signed-off-by: Harald Freudenberger Reviewed-by: Holger Dengler Reviewed-by: Juergen Christ Cc: stable@vger.kernel.org Signed-off-by: Heiko Carstens Signed-off-by: Greg Kroah-Hartman