This patch prepares for a version of libunwind that is capable of
unwinding stacks with pointer authentication.
Without this change, anyone compiling perf would have to depend on a
very new version of libunwind that has the callback to supply it with
pointer authentication masks.
This patch detects if libunwind is recent enough, and if so, sets a
pre-processor flag that will be used in a subsequent commit to call
libunwind appropriately.
If libunwind is not recent enough, the pre-processor flag is not set.
Signed-off-by: Andrew Kilroy <andrew.kilroy@xxxxxxx>
---
tools/build/Makefile.feature | 2 ++
tools/build/feature/Makefile | 4 +++
tools/build/feature/test-all.c | 5 ++++
.../feature/test-libunwind-arm64-ptrauth.c | 26 +++++++++++++++++++
tools/perf/Makefile.config | 10 +++++++
5 files changed, 47 insertions(+)
create mode 100644 tools/build/feature/test-libunwind-arm64-ptrauth.c
diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
index 888a0421d43b..a894101342fc 100644
--- a/tools/build/Makefile.feature
+++ b/tools/build/Makefile.feature
@@ -90,6 +90,7 @@ FEATURE_TESTS_EXTRA := \
libunwind-x86_64 \
libunwind-arm \
libunwind-aarch64 \
+ libunwind-arm64-ptrauth \
libunwind-debug-frame \
libunwind-debug-frame-arm \
libunwind-debug-frame-aarch64 \
@@ -128,6 +129,7 @@ FEATURE_DISPLAY ?= \
libpython \
libcrypto \
libunwind \
+ libunwind-arm64-ptrauth\
libdw-dwarf-unwind \
zlib \
lzma \
diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
index 7c2a17e23c30..ac23175d5bcb 100644
--- a/tools/build/feature/Makefile
+++ b/tools/build/feature/Makefile
@@ -45,6 +45,7 @@ FILES= \
test-libunwind-aarch64.bin \
test-libunwind-debug-frame-arm.bin \
test-libunwind-debug-frame-aarch64.bin \
+ test-libunwind-arm64-ptrauth.bin \
test-pthread-attr-setaffinity-np.bin \
test-pthread-barrier.bin \
test-stackprotector-all.bin \
@@ -193,6 +194,9 @@ $(OUTPUT)test-libunwind-debug-frame-arm.bin:
$(OUTPUT)test-libunwind-debug-frame-aarch64.bin:
$(BUILD) -lelf -lunwind-aarch64
+$(OUTPUT)test-libunwind-arm64-ptrauth.bin:
+ $(BUILD) # -lunwind provided by $(FEATURE_CHECK_LDFLAGS-libunwind-arm64-ptrauth)
+
$(OUTPUT)test-libaudit.bin:
$(BUILD) -laudit
diff --git a/tools/build/feature/test-all.c b/tools/build/feature/test-all.c
index 5ffafb967b6e..86780c5c78e5 100644
--- a/tools/build/feature/test-all.c
+++ b/tools/build/feature/test-all.c
@@ -66,6 +66,10 @@
# include "test-libunwind.c"
#undef main
+#define main main_test_libunwind_arm64_ptrauth
+# include "test-libunwind-arm64-ptrauth.c"
+#undef main
+
#define main main_test_libslang
# include "test-libslang.c"
#undef main
@@ -186,6 +190,7 @@ int main(int argc, char *argv[])
main_test_libelf_gelf_getnote();
main_test_libelf_getshdrstrndx();
main_test_libunwind();
+ main_test_libunwind_arm64_ptrauth();
main_test_libslang();
main_test_libbfd();
main_test_libbfd_buildid();
diff --git a/tools/build/feature/test-libunwind-arm64-ptrauth.c b/tools/build/feature/test-libunwind-arm64-ptrauth.c
new file mode 100644
index 000000000000..51650ceef90e
--- /dev/null
+++ b/tools/build/feature/test-libunwind-arm64-ptrauth.c
@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <libunwind.h>
+
+static unw_word_t get_insn_mask(unw_addr_space_t addr_space, void *unwind_info_ptr)
+{
+ return 0;
+}
+
+// This feature test is intending to check if the version
+// of the available libunwind library is one that has the
+// ptrauth_insn_mask callback function.
+// If it doesn't this feature check should fail to compile.
+static unw_accessors_t accessors = {
+ .ptrauth_insn_mask = get_insn_mask,
+};
+
+int main(void)
+{
+ unw_addr_space_t addr_space = unw_create_addr_space(&accessors, 0);
+
+ if (addr_space)
+ return 0;
+
+ return 0;
+}
diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 73e0762092fe..2578b1d1a502 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -133,6 +133,8 @@ FEATURE_CHECK_CFLAGS-libunwind = $(LIBUNWIND_CFLAGS)
FEATURE_CHECK_LDFLAGS-libunwind = $(LIBUNWIND_LDFLAGS) $(LIBUNWIND_LIBS)
FEATURE_CHECK_CFLAGS-libunwind-debug-frame = $(LIBUNWIND_CFLAGS)
FEATURE_CHECK_LDFLAGS-libunwind-debug-frame = $(LIBUNWIND_LDFLAGS) $(LIBUNWIND_LIBS)
+FEATURE_CHECK_CFLAGS-libunwind-arm64-ptrauth = $(LIBUNWIND_CFLAGS)
+FEATURE_CHECK_LDFLAGS-libunwind-arm64-ptrauth = $(LIBUNWIND_LDFLAGS) $(LIBUNWIND_LIBS)
FEATURE_CHECK_LDFLAGS-libunwind-arm += -lunwind -lunwind-arm
FEATURE_CHECK_LDFLAGS-libunwind-aarch64 += -lunwind -lunwind-aarch64
@@ -677,6 +679,14 @@ ifndef NO_LIBUNWIND
$(call detected,CONFIG_LOCAL_LIBUNWIND)
endif
+ ifeq ($(have_libunwind), 1)
+ $(call feature_check,libunwind-arm64-ptrauth)
+ ifneq ($(feature-libunwind-arm64-ptrauth),1)
+ CFLAGS += -DNO_LIBUNWIND_ARM64_PTRAUTH
+ msg := $(warning libunwind cannot produce user stacks in the presence of pointer authentication.);
+ endif
+ endif
+
ifneq ($(have_libunwind), 1)
NO_LIBUNWIND := 1
endif
--
2.17.1
