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authorIan Rogers <irogers@google.com>2020-05-30 01:20:13 -0700
committerArnaldo Carvalho de Melo <acme@redhat.com>2020-06-01 12:24:21 -0300
commit21f2b7c13335eeec498569927d87c7381c3b54fa (patch)
treeabb274291b945d3690e9e10622b82e26c0f7902d /tools/include
parent9300acc6fed8e957c8d60f6f8e4451b508feea2c (diff)
downloadlinux-21f2b7c13335eeec498569927d87c7381c3b54fa.tar.bz2
tools compiler.h: Add attribute to disable tail calls
Tail call optimizations can remove stack frames that are used in unwinding tests. Add an attribute that can be used to disable the tail call optimization. Tested on clang and GCC. Committer notes: Old versions of clang don't like that __attribute__((optimize)), so add an ifdef to make it go away. Signed-off-by: Ian Rogers <irogers@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: clang-built-linux@googlegroups.com Cc: Jakub Kicinski <kuba@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Monnet <quentin@isovalent.com> Cc: Stephane Eranian <eranian@google.com> Link: http://lore.kernel.org/lkml/20200530082015.39162-2-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/include')
-rw-r--r--tools/include/linux/compiler-gcc.h12
-rw-r--r--tools/include/linux/compiler.h3
2 files changed, 15 insertions, 0 deletions
diff --git a/tools/include/linux/compiler-gcc.h b/tools/include/linux/compiler-gcc.h
index 95c072b70d0e..b9d4322e1e65 100644
--- a/tools/include/linux/compiler-gcc.h
+++ b/tools/include/linux/compiler-gcc.h
@@ -27,6 +27,18 @@
#define __pure __attribute__((pure))
#endif
#define noinline __attribute__((noinline))
+#ifdef __has_attribute
+#if __has_attribute(disable_tail_calls)
+#define __no_tail_call __attribute__((disable_tail_calls))
+#endif
+#endif
+#ifndef __no_tail_call
+#if GCC_VERSION > 40201
+#define __no_tail_call __attribute__((optimize("no-optimize-sibling-calls")))
+#else
+#define __no_tail_call
+#endif
+#endif
#ifndef __packed
#define __packed __attribute__((packed))
#endif
diff --git a/tools/include/linux/compiler.h b/tools/include/linux/compiler.h
index 180f7714a5f1..9f9002734e19 100644
--- a/tools/include/linux/compiler.h
+++ b/tools/include/linux/compiler.h
@@ -47,6 +47,9 @@
#ifndef noinline
#define noinline
#endif
+#ifndef __no_tail_call
+#define __no_tail_call
+#endif
/* Are two types/vars the same type (ignoring qualifiers)? */
#ifndef __same_type