linux-dev/arch/s390/kernel/perf_event.c, branch linus/master

s390/stack: add union to reflect kvm stack slot usages

2022-06-01T10:03:17Z

Add a union which describes how the empty stack slots are being used by kvm and perf. This should help to avoid another bug like the one which was fixed with commit c9bfb460c3e4 ("s390/perf: obtain sie_block from the right address"). Reviewed-by: Nico Boehr Tested-by: Nico Boehr Signed-off-by: Heiko Carstens

s390/stack: merge empty stack frame slots

2022-06-01T10:03:17Z

Merge empty1 and empty2 arrays within the stack frame to one single array. This is possible since with commit 42b01a553a56 ("s390: always use the packed stack layout") the alternative stack frame layout is gone. Reviewed-by: Nico Boehr Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens

s390/perf: obtain sie_block from the right address

2022-05-25T09:46:02Z

Since commit 1179f170b6f0 ("s390: fix fpu restore in entry.S"), the sie_block pointer is located at empty1[1], but in sie_block() it was taken from empty1[0]. This leads to a random pointer being dereferenced, possibly causing system crash. This problem can be observed when running a simple guest with an endless loop and recording the cpu-clock event: sudo perf kvm --guestvmlinux= --guest top -e cpu-clock With this fix, the correct guest address is shown. Fixes: 1179f170b6f0 ("s390: fix fpu restore in entry.S") Cc: stable@vger.kernel.org Acked-by: Christian Borntraeger Acked-by: Claudio Imbrenda Reviewed-by: Heiko Carstens Signed-off-by: Nico Boehr Signed-off-by: Heiko Carstens

s390: get rid of oprofile leftovers

2021-04-18T19:32:02Z

perf_pmu_name() and perf_num_counters() are unused. Drop them. Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210414134409.1266357-4-maz@kernel.org Signed-off-by: Heiko Carstens

s390: add error handling to perf_callchain_kernel

2019-10-31T16:20:54Z

perf_callchain_kernel stops neither when it encounters a garbage address, nor when it runs out of space. Fix both issues using x86 version as an inspiration. Signed-off-by: Ilya Leoshkevich Signed-off-by: Vasily Gorbik

s390/unwind: introduce stack unwind API

2019-05-02T11:54:11Z

Rework the dump_trace() stack unwinder interface to support different unwinding algorithms. The new interface looks like this: struct unwind_state state; unwind_for_each_frame(&state, task, regs, start_stack) do_something(state.sp, state.ip, state.reliable); The unwind_bc.c file contains the implementation for the classic back-chain unwinder. One positive side effect of the new code is it now handles ftraced functions gracefully. It prints the real name of the return function instead of 'return_to_handler'. Signed-off-by: Martin Schwidefsky

s390: kernel: Remove redundant license text

2017-11-24T14:37:20Z

Now that the SPDX tag is in all arch/s390/kernel/ files, that identifies the license in a specific and legally-defined manner. So the extra GPL text wording can be removed as it is no longer needed at all. This is done on a quest to remove the 700+ different ways that files in the kernel describe the GPL license text. And there's unneeded stuff like the address (sometimes incorrect) for the FSF which is never needed. No copyright headers or other non-license-description text was removed. Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Namhyung Kim Cc: "Paul E. McKenney" Signed-off-by: Greg Kroah-Hartman Signed-off-by: Martin Schwidefsky

s390: kernel: add SPDX identifiers to the remaining files

2017-11-24T14:37:12Z

It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the arch/s390/kernel/ files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Namhyung Kim Cc: Thomas Gleixner Cc: Kate Stewart Cc: Philippe Ombredanne Signed-off-by: Greg Kroah-Hartman Signed-off-by: Martin Schwidefsky

s390/perf: fix null string in perf list pmu command

2017-06-12T14:26:00Z

Command 'perf list pmu' displays events which contain an invalid string "(null)=xxx", where xxx is the pmu event name, for example: cpum_cf/AES_BLOCKED_CYCLES,(null)=AES_BLOCKED_CYCLES/ This is not correct, the invalid string should not be displayed at all. It is caused by an obsolete term in the sysfs attribute file for each s390 CPUMF counter event. Reading from the sysfs file also displays the event name. Fix this by omitting the event name. This patch makes s390 CPUMF sysfs files consistent with other plattforms. This is an interface change between user and kernel but does not break anything. Reading from a counter event sysfs file should only list terms mentioned in the /sys/bus/event_source/devices//format directory. Name is not listed. Reported-by: Zvonko Kosic Signed-off-by: Thomas Richter Reviewed-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky

s390/dumpstack: restore reliable indicator for call traces

2016-10-17T12:44:30Z

Before merging all different stack tracers the call traces printed had an indicator if an entry can be considered reliable or not. Unreliable entries were put in braces, reliable not. Currently all lines contain these extra braces. This patch restores the old behaviour by adding an extra "reliable" parameter to the callback functions. Only show_trace makes currently use of it. Before: [ 0.804751] Call Trace: [ 0.804753] ([<000000000017d0e0>] try_to_wake_up+0x318/0x5e0) [ 0.804756] ([<0000000000161d64>] create_worker+0x174/0x1c0) After: [ 0.804751] Call Trace: [ 0.804753] ([<000000000017d0e0>] try_to_wake_up+0x318/0x5e0) [ 0.804756] [<0000000000161d64>] create_worker+0x174/0x1c0 Fixes: 758d39ebd3d5 ("s390/dumpstack: merge all four stack tracers") Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky