kernel.git/arch/s390/kernel, branch linux-5.8.y

s390/init: add missing __init annotations

2020-10-01T15:36:24Z

[ Upstream commit fcb2b70cdb194157678fb1a75f9ff499aeba3d2a ] Add __init to reserve_memory_end, reserve_oldmem and remove_oldmem. Sometimes these functions are not inlined, and then the build complains about section mismatch. Signed-off-by: Ilya Leoshkevich Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin

s390: add 3f program exception handler

2020-09-23T11:00:02Z

commit cd4d3d5f21ddbfae3f686ac0ff405f21f7847ad3 upstream. Program exception 3f (secure storage violation) can only be detected when the CPU is running in SIE with a format 4 state description, e.g. running a protected guest. Because of this and because user space partly controls the guest memory mapping and can trigger this exception, we want to send a SIGSEGV to the process running the guest and not panic the kernel. Signed-off-by: Janosch Frank Cc: # 5.7 Fixes: 084ea4d611a3 ("s390/mm: add (non)secure page access exceptions handlers") Reviewed-by: Claudio Imbrenda Reviewed-by: Cornelia Huck Acked-by: Christian Borntraeger Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman

s390/ptrace: fix storage key handling

2020-08-26T09:49:12Z

[ Upstream commit fd78c59446b8d050ecf3e0897c5a486c7de7c595 ] The key member of the runtime instrumentation control block contains only the access key, not the complete storage key. Therefore the value must be shifted by four bits. Since existing user space does not necessarily query and set the access key correctly, just ignore the user space provided key and use the correct one. Note: this is only relevant for debugging purposes in case somebody compiles a kernel with a default storage access key set to a value not equal to zero. Fixes: 262832bc5acd ("s390/ptrace: add runtime instrumention register get/set") Reported-by: Claudio Imbrenda Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin

s390/runtime_instrumentation: fix storage key handling

2020-08-26T09:49:12Z

[ Upstream commit 9eaba29c7985236e16468f4e6a49cc18cf01443e ] The key member of the runtime instrumentation control block contains only the access key, not the complete storage key. Therefore the value must be shifted by four bits. Note: this is only relevant for debugging purposes in case somebody compiles a kernel with a default storage access key set to a value not equal to zero. Fixes: e4b8b3f33fca ("s390: add support for runtime instrumentation") Reported-by: Claudio Imbrenda Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin

s390/cpum_cf,perf: change DFLT_CCERROR counter name

2020-07-21T11:53:56Z

Change the counter name DLFT_CCERROR to DLFT_CCFINISH on IBM z15. This counter counts completed DEFLATE instructions with exit code 0, 1 or 2. Since exit code 0 means success and exit code 1 or 2 indicate errors, change the counter name to avoid confusion. This counter is incremented each time the DEFLATE instruction completed regardless if an error was detected or not. Fixes: d68d5d51dc89 ("s390/cpum_cf: Add new extended counters for IBM z15") Fixes: e7950166e402 ("perf vendor events s390: Add new deflate counters for IBM z15") Cc: stable@vger.kernel.org # v5.7 Signed-off-by: Thomas Richter Reviewed-by: Sumanth Korikkar Signed-off-by: Heiko Carstens

s390/cpum_sf: prohibit callchain data collection

2020-07-01T18:02:33Z

CPU Measurement sampling facility on s390 does not support perf tool collection of callchain data using --call-graph option. The sampling facility collects samples in a ring buffer which includes only the instruction address the samples were taken. When the ring buffer hits a watermark, a measurement alert interrupt is triggered and handled by the performance measurement unit (PMU) device driver. It collects the samples and feeds each sample to the perf ring buffer in the common code via functions perf_prepare_sample()/perf_output_sample(). When function perf_prepare_sample() is called to collect sample data's callchain, user register values or stack area, invalid data is picked, because the context of the collected information does not match the context when the sample was taken. There is currently no way to provide the callchain and other information, because the hardware sampler does not collect this information. Therefore prohibit sampling when the user requests a callchain graph from the hardware sampler. Return -EOPNOTSUPP to the user in this case. If call chains are really wanted, users need to specify software event cpu-clock to get the callchain information from a software event. Signed-off-by: Thomas Richter Reviewed-by: Sumanth Korikkar Signed-off-by: Heiko Carstens

s390/setup: init jump labels before command line parsing

2020-06-29T14:28:39Z

Command line parameters might set static keys. This is true for s390 at least since commit 6471384af2a6 ("mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options"). To avoid the following WARN: static_key_enable_cpuslocked(): static key 'init_on_alloc+0x0/0x40' used before call to jump_label_init() call jump_label_init() just before parse_early_param(). jump_label_init() is safe to call multiple times (x86 does that), doesn't do any memory allocations and hence should be safe to call that early. Fixes: 6471384af2a6 ("mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options") Cc: # 5.3: d6df52e9996d: s390/maccess: add no DAT mode to kernel_write Cc: # 5.3 Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Heiko Carstens

s390/debug: avoid kernel warning on too large number of pages

2020-06-23T12:05:55Z

When specifying insanely large debug buffers a kernel warning is printed. The debug code does handle the error gracefully, though. Instead of duplicating the check let us silence the warning to avoid crashes when panic_on_warn is used. Signed-off-by: Christian Borntraeger Reviewed-by: Heiko Carstens Signed-off-by: Heiko Carstens

s390/kasan: fix early pgm check handler execution

2020-06-23T12:05:50Z

Currently if early_pgm_check_handler is called it ends up in pgm check loop. The problem is that early_pgm_check_handler is instrumented by KASAN but executed without DAT flag enabled which leads to addressing exception when KASAN checks try to access shadow memory. Fix that by executing early handlers with DAT flag on under KASAN as expected. Reported-and-tested-by: Alexander Egorenkov Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Heiko Carstens

s390: fix system call single stepping

2020-06-23T12:05:45Z

When single stepping an svc instruction on s390, the kernel is entered with a PER program check interruption. The program check handler than jumps to the system call handler by reloading the PSW. The code didn't set GPR13 to the thread pointer in struct task_struct. This made the kernel access invalid memory while trying to fetch the syscall function address. Fix this by always assigned GPR13 after .Lsysc_per. Fixes: 0b0ed657fe00 ("s390: remove critical section cleanup from entry.S") Reported-and-tested-by: Christian Borntraeger Signed-off-by: Sven Schnelle Reviewed-by: Heiko Carstens Signed-off-by: Heiko Carstens