From c3e0ce9f2eac6ef8657589dc461e69e2b36e6707 Mon Sep 17 00:00:00 2001 From: Alexander Shishkin Date: Tue, 19 Mar 2019 09:55:33 +0800 Subject: [PATCH] perf: Copy parent's address filter offsets on clone mainline inclusion from mainline-5.1-rc1 commit 18736eef12137c59f60cc9f56dc5bea05c92e0eb category: bugfix bugzilla: 11595 CVE: NA ------------------------------------------------- When a child event is allocated in the inherit_event() path, the VMA based filter offsets are not copied from the parent, even though the address space mapping of the new task remains the same, which leads to no trace for the new task until exec. Reported-by: Mansour Alharthi Signed-off-by: Alexander Shishkin Tested-by: Mathieu Poirier Acked-by: Peter Zijlstra Cc: Jiri Olsa Fixes: 375637bc5249 ("perf/core: Introduce address range filtering") Link: http://lkml.kernel.org/r/20190215115655.63469-2-alexander.shishkin@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo (cherry picked from commit 18736eef12137c59f60cc9f56dc5bea05c92e0eb) Signed-off-by: Zhen Lei Reviewed-by: Cheng Jian Signed-off-by: Yang Yingliang --- kernel/events/core.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/kernel/events/core.c b/kernel/events/core.c index 40392a6ff0f0..b7b9bcdfa2ab 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -1254,6 +1254,7 @@ static void put_ctx(struct perf_event_context *ctx) * perf_event_context::lock * perf_event::mmap_mutex * mmap_sem + * perf_addr_filters_head::lock * * cpu_hotplug_lock * pmus_lock @@ -10099,6 +10100,20 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu, goto err_per_task; } + /* + * Clone the parent's vma offsets: they are valid until exec() + * even if the mm is not shared with the parent. + */ + if (event->parent) { + struct perf_addr_filters_head *ifh = perf_event_addr_filters(event); + + raw_spin_lock_irq(&ifh->lock); + memcpy(event->addr_filters_offs, + event->parent->addr_filters_offs, + pmu->nr_addr_filters * sizeof(unsigned long)); + raw_spin_unlock_irq(&ifh->lock); + } + /* force hw sync on the address filters */ event->addr_filters_gen = 1; } -- GitLab