Commit ec1891af authored by Adrian Hunter's avatar Adrian Hunter Committed by Arnaldo Carvalho de Melo
Browse files

perf machine: Record if a arch has a single user/kernel address space 



Some architectures have a single address space for kernel and user
addresses, which makes it possible to determine if an address is in
kernel space or user space. Some don't, e.g.: sparc.

Cache that info in perf_env so that, for instance, code needing to
fallback failed symbol lookups at the kernel space in single address
space arches can lookup at userspace.

Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: stable@vger.kernel.org # 4.19
Link: http://lkml.kernel.org/r/20181106210712.12098-2-adrian.hunter@intel.com


[ split from a larger patch ]
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 804234f2

tools/perf/arch/common.c

+10 −0
Original line number Diff line number Diff line
@@ -200,3 +200,13 @@ int perf_env__lookup_objdump(struct perf_env *env, const char **path) 


	return perf_env__lookup_binutils_path(env, "objdump", path);

}



/*

 * Some architectures have a single address space for kernel and user addresses,

 * which makes it possible to determine if an address is in kernel space or user

 * space.

 */

bool perf_env__single_address_space(struct perf_env *env)

{

	return strcmp(perf_env__arch(env), "sparc");

}

tools/perf/arch/common.h

+1 −0
Original line number Diff line number Diff line
@@ -5,5 +5,6 @@ 
#include "../util/env.h"



int perf_env__lookup_objdump(struct perf_env *env, const char **path);

bool perf_env__single_address_space(struct perf_env *env);



#endif /* ARCH_PERF_COMMON_H */

tools/perf/util/machine.h

+1 −0
Original line number Diff line number Diff line
@@ -42,6 +42,7 @@ struct machine { 
	u16		  id_hdr_size;

	bool		  comm_exec;

	bool		  kptr_restrict_warned;

	bool		  single_address_space;

	char		  *root_dir;

	char		  *mmap_name;

	struct threads    threads[THREADS__TABLE_SIZE];

tools/perf/util/session.c

+4 −0
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ 
#include "thread.h"

#include "thread-stack.h"

#include "stat.h"

#include "arch/common.h"



static int perf_session__deliver_event(struct perf_session *session,

				       union perf_event *event,
@@ -150,6 +151,9 @@ struct perf_session *perf_session__new(struct perf_data *data, 
		session->machines.host.env = &perf_env;

	}



	session->machines.host.single_address_space =

		perf_env__single_address_space(session->machines.host.env);



	if (!data || perf_data__is_write(data)) {

		/*

		 * In O_RDONLY mode this will be performed when reading the

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