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 <jolsa@kernel.org>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: chenggang.qcg@taobao.com
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/e431cd4c18c2e1c44c774f10758527fb2d1025c4.1420396372.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 486e84c..4f7a61c 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -79,11 +79,6 @@
struct perf_branch_entry entries[0];
};
-struct perf_regs {
- __u64 abi;
- struct pt_regs *regs;
-};
-
struct task_struct;
/*
@@ -610,7 +605,14 @@
u32 reserved;
} cpu_entry;
struct perf_callchain_entry *callchain;
+
+ /*
+ * regs_user may point to task_pt_regs or to regs_user_copy, depending
+ * on arch details.
+ */
struct perf_regs regs_user;
+ struct pt_regs regs_user_copy;
+
struct perf_regs regs_intr;
u64 stack_user_size;
} ____cacheline_aligned;