From 892144d3f1cdf7a916d359e6e3af019c5df46623 Mon Sep 17 00:00:00 2001 From: Ravi Bangoria Date: Tue, 27 Sep 2022 21:08:22 +0800 Subject: [PATCH] perf/amd/ibs: Use interrupt regs ip for stack unwinding stable inclusion from stable-v5.10.121 commit 779d41c80b10043cfb6d2cd70a7b45c4e5ac883c category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5L6CQ Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=779d41c80b10043cfb6d2cd70a7b45c4e5ac883c -------------------------------- [ Upstream commit 3d47083b9ff46863e8374ad3bb5edb5e464c75f8 ] IbsOpRip is recorded when IBS interrupt is triggered. But there is a skid from the time IBS interrupt gets triggered to the time the interrupt is presented to the core. Meanwhile processor would have moved ahead and thus IbsOpRip will be inconsistent with rsp and rbp recorded as part of the interrupt regs. This causes issues while unwinding stack using the ORC unwinder as it needs consistent rip, rsp and rbp. Fix this by using rip from interrupt regs instead of IbsOpRip for stack unwinding. Fixes: ee9f8fce99640 ("x86/unwind: Add the ORC unwinder") Reported-by: Dmitry Monakhov Suggested-by: Peter Zijlstra Signed-off-by: Ravi Bangoria Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20220429051441.14251-1-ravi.bangoria@amd.com Signed-off-by: Sasha Levin Signed-off-by: Zheng Zengkai Acked-by: Xie XiuQi --- arch/x86/events/amd/ibs.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c index 780d89d2ae32..8a85658a24cc 100644 --- a/arch/x86/events/amd/ibs.c +++ b/arch/x86/events/amd/ibs.c @@ -312,6 +312,16 @@ static int perf_ibs_init(struct perf_event *event) hwc->config_base = perf_ibs->msr; hwc->config = config; + /* + * rip recorded by IbsOpRip will not be consistent with rsp and rbp + * recorded as part of interrupt regs. Thus we need to use rip from + * interrupt regs while unwinding call stack. Setting _EARLY flag + * makes sure we unwind call-stack before perf sample rip is set to + * IbsOpRip. + */ + if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) + event->attr.sample_type |= __PERF_SAMPLE_CALLCHAIN_EARLY; + return 0; } @@ -692,6 +702,14 @@ static int perf_ibs_handle_irq(struct perf_ibs *perf_ibs, struct pt_regs *iregs) data.raw = &raw; } + /* + * rip recorded by IbsOpRip will not be consistent with rsp and rbp + * recorded as part of interrupt regs. Thus we need to use rip from + * interrupt regs while unwinding call stack. + */ + if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) + data.callchain = perf_callchain(event, iregs); + throttle = perf_event_overflow(event, &data, ®s); out: if (throttle) { -- GitLab