From 88a7c26af8dab2f2d69f5a6067eb670694ec38c0 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Sun, 4 Jan 2015 10:36:19 -0800 Subject: perf: Move task_pt_regs sampling into arch code On x86_64, at least, task_pt_regs may be only partially initialized in many contexts, so x86_64 should not use it without extra care from interrupt context, let alone NMI context. This will allow x86_64 to override the logic and will supply some scratch space to use to make a cleaner copy of user regs. Tested-by: Jiri Olsa Signed-off-by: Andy Lutomirski Signed-off-by: Peter Zijlstra (Intel) Cc: Stephane Eranian Cc: chenggang.qcg@taobao.com Cc: Wu Fengguang Cc: Namhyung Kim Cc: Mike Galbraith Cc: Arjan van de Ven Cc: David Ahern Cc: Arnaldo Carvalho de Melo Cc: Catalin Marinas Cc: Jean Pihet Cc: Linus Torvalds Cc: Mark Salter Cc: Russell King Cc: Will Deacon Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/e431cd4c18c2e1c44c774f10758527fb2d1025c4.1420396372.git.luto@amacapital.net Signed-off-by: Ingo Molnar --- kernel/events/core.c | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-) (limited to 'kernel/events/core.c') diff --git a/kernel/events/core.c b/kernel/events/core.c index 4c1ee7f2bebc..882f835a0d85 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -4461,18 +4461,14 @@ perf_output_sample_regs(struct perf_output_handle *handle, } static void perf_sample_regs_user(struct perf_regs *regs_user, - struct pt_regs *regs) + struct pt_regs *regs, + struct pt_regs *regs_user_copy) { - if (!user_mode(regs)) { - if (current->mm) - regs = task_pt_regs(current); - else - regs = NULL; - } - - if (regs) { - regs_user->abi = perf_reg_abi(current); + if (user_mode(regs)) { + regs_user->abi = perf_reg_abi(current); regs_user->regs = regs; + } else if (current->mm) { + perf_get_regs_user(regs_user, regs, regs_user_copy); } else { regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE; regs_user->regs = NULL; @@ -4951,7 +4947,8 @@ void perf_prepare_sample(struct perf_event_header *header, } if (sample_type & (PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER)) - perf_sample_regs_user(&data->regs_user, regs); + perf_sample_regs_user(&data->regs_user, regs, + &data->regs_user_copy); if (sample_type & PERF_SAMPLE_REGS_USER) { /* regs dump ABI info */ -- cgit v1.2.3