kernel/linux.git/tools/perf/util/thread-stack.c, branch v6.6.131

x86/retpoline,kprobes: Skip optprobe check for indirect jumps with retpolines and IBT

2023-08-14T09:46:51+00:00

The kprobes optimization check can_optimize() calls insn_is_indirect_jump() to detect indirect jump instructions in a target function. If any is found, creating an optprobe is disallowed in the function because the jump could be from a jump table and could potentially land in the middle of the target optprobe. With retpolines, insn_is_indirect_jump() additionally looks for calls to indirect thunks which the compiler potentially used to replace original jumps. This extra check is however unnecessary because jump tables are disabled when the kernel is built with retpolines. The same is currently the case with IBT. Based on this observation, remove the logic to look for calls to indirect thunks and skip the check for indirect jumps altogether if the kernel is built with retpolines or IBT. Remove subsequently the symbols __indirect_thunk_start and __indirect_thunk_end which are no longer needed. Dropping this logic indirectly fixes a problem where the range [__indirect_thunk_start, __indirect_thunk_end] wrongly included also the return thunk. It caused that machines which used the return thunk as a mitigation and didn't have it patched by any alternative ended up not being able to use optprobes in any regular function. Fixes: 0b53c374b9ef ("x86/retpoline: Use -mfunction-return") Suggested-by: Peter Zijlstra (Intel) Suggested-by: Masami Hiramatsu (Google) Signed-off-by: Petr Pavlu Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Borislav Petkov (AMD) Acked-by: Masami Hiramatsu (Google) Link: https://lore.kernel.org/r/20230711091952.27944-3-petr.pavlu@suse.com

perf thread: Add accessor functions for thread

2023-06-12T18:57:53+00:00

Using accessors will make it easier to add reference count checking in later patches. Committer notes: thread->nsinfo wasn't wrapped as it is used together with nsinfo__zput(), where does a trick to set the field with a refcount being dropped to NULL, and that doesn't work well with using thread__nsinfo(thread), that loses the &thread->nsinfo pointer. When refcount checking is added to 'struct thread', later in this series, nsinfo__zput(RC_CHK_ACCESS(thread)->nsinfo) will be used to check the thread pointer. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ali Saidi Cc: Andi Kleen Cc: Athira Rajeev Cc: Brian Robbins Cc: Changbin Du Cc: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: Fangrui Song Cc: German Gomez Cc: Ingo Molnar Cc: Ivan Babrou Cc: James Clark Cc: Jing Zhang Cc: Jiri Olsa Cc: John Garry Cc: K Prateek Nayak Cc: Kan Liang Cc: Leo Yan Cc: Liam Howlett Cc: Mark Rutland Cc: Miguel Ojeda Cc: Mike Leach Cc: Namhyung Kim Cc: Naveen N. Rao Cc: Peter Zijlstra Cc: Ravi Bangoria Cc: Sean Christopherson Cc: Steinar H. Gunderson Cc: Suzuki Poulouse Cc: Wenyu Liu Cc: Will Deacon Cc: Yang Jihong Cc: Ye Xingchen Cc: Yuan Can Cc: coresight@lists.linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: https://lore.kernel.org/r/20230608232823.4027869-4-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf maps: Add functions to access maps

2023-04-04T18:45:38+00:00

Introduce functions to access struct maps. These functions reduce the number of places reference counting is necessary. While tidying APIs do some small const-ification, in particlar to unwind_libunwind_ops. Committer notes: Fixed up tools/perf/util/unwind-libunwind.c: - return ops->get_entries(cb, arg, thread, data, max_stack); + return ops->get_entries(cb, arg, thread, data, max_stack, best_effort); Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Alexey Bayduraev Cc: Andi Kleen Cc: Andrew Morton Cc: Andy Shevchenko Cc: Darren Hart Cc: Davidlohr Bueso Cc: Dmitriy Vyukov Cc: Eric Dumazet Cc: German Gomez Cc: Hao Luo Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: John Garry Cc: Kajol Jain Cc: Kan Liang Cc: Leo Yan Cc: Madhavan Srinivasan Cc: Mark Rutland Cc: Masami Hiramatsu Cc: Miaoqian Lin Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Riccardo Mancini Cc: Shunsuke Nakamura Cc: Song Liu Cc: Stephane Eranian Cc: Stephen Brennan Cc: Steven Rostedt (VMware) Cc: Thomas Gleixner Cc: Thomas Richter Cc: Yury Norov Link: https://lore.kernel.org/r/20230320212248.1175731-2-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf thread-stack: Add thread_stack__br_sample_late()

2020-05-05T19:35:29+00:00

Add a thread stack function to create a branch stack for hardware events where the sample records get created some time after the event occurred. Signed-off-by: Adrian Hunter Cc: Andi Kleen Cc: Jiri Olsa Link: http://lore.kernel.org/lkml/20200429150751.12570-7-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf thread-stack: Add branch stack support

2020-05-05T19:35:29+00:00

Intel PT already has support for creating branch stacks for each context (per-cpu or per-thread). In the more common per-cpu case, the branch stack is not separated for different threads, instead being cleared in between each sample. That approach will not work very well for adding branch stacks to regular events. The branch stacks really need to be accumulated separately for each thread. As a start to accomplishing that, this patch adds support for putting branch stack support into the thread-stack. The advantages are: 1. the branches are accumulated separately for each thread 2. the branch stack is cleared only in between continuous traces This helps pave the way for adding branch stacks to regular events, not just synthesized events as at present. Signed-off-by: Adrian Hunter Cc: Andi Kleen Cc: Jiri Olsa Link: http://lore.kernel.org/lkml/20200429150751.12570-2-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf thread-stack: Add thread_stack__sample_late()

2020-04-16T15:19:15+00:00

Add a thread stack function to create a call chain for hardware events where the sample records get created some time after the event occurred. Signed-off-by: Adrian Hunter Cc: Andi Kleen Cc: Jiri Olsa Link: http://lore.kernel.org/lkml/20200401101613.6201-10-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf thread: Rename thread->mg to thread->maps

2019-11-26T14:07:46+00:00

One more step on the merge of 'struct maps' with 'struct map_groups'. Cc: Adrian Hunter Cc: Andi Kleen Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lkml.kernel.org/n/tip-69vcr8pubpym90skxhmbwhiw@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf debug: Remove needless include directives from debug.h

2019-08-31T22:10:19+00:00

All we need there is a forward declaration for 'union perf_event', so remove it from there and add missing header directives in places using things from this indirect include. Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lkml.kernel.org/n/tip-7ftk0ztstqub1tirjj8o8xbl@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

tools lib: Adopt zalloc()/zfree() from tools/perf

2019-07-09T13:13:26+00:00

Eroding a bit more the tools/perf/util/util.h hodpodge header. Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lkml.kernel.org/n/tip-natazosyn9rwjka25tvcnyi0@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Add missing headers, mostly stdlib.h

2019-07-09T13:13:22+00:00

Part of the erosion of util/util.h, that will lose its include stdlib.h, we need to add it to places where it is needed but was getting it indirectly. Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lkml.kernel.org/n/tip-1imnqezw99ahc07fjeb51qby@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo