From 906a8276429c7eb3b53676dab4e2acb632ffcc5a Mon Sep 17 00:00:00 2001 From: He Kuang Date: Wed, 15 Jun 2016 11:03:56 +0000 Subject: [PATCH] perf unwind: Fix compile error for static cross build Build failure for static cross-compiling on aarch64, with libunwind-x86 provided: $ file ./libunwind_for_x86_on_aarch64/lib/libunwind-x86.so.8.0.1 libunwind-x86.so.8.0.1: ELF 64-bit LSB shared object, ARM aarch64, version 1 (SYSV), dynamically linked, not stripped $ make LDFLAGS=-static LIBUNWIND_DIR=./libunwind_for_x86_on_aarch64 ARCH=aarch64 CROSS_COMPILE=aarch64-buildroot-linux-gnu- ~/libperf.a(libperf-in.o): In function `find_proc_info': :(.text+0xae4ac): undefined reference to `_Ux86_dwarf_search_unwind_table' ~/libperf.a(libperf-in.o): In function `_unwind__prepare_access': :(.text+0xaedd0): undefined reference to `_Ux86_create_addr_space' :(.text+0xaee24): undefined reference to `_Ux86_set_caching_policy' ~/libperf.a(libperf-in.o): In function `_unwind__flush_access': :(.text+0xaee98): undefined reference to `_Ux86_flush_cache' ~/libperf.a(libperf-in.o): In function `_unwind__finish_access': :(.text+0xaef08): undefined reference to `_Ux86_destroy_addr_space' ~/libperf.a(libperf-in.o): In function `get_entries': :(.text+0xaf148): undefined reference to `_Ux86_init_remote' :(.text+0xaf184): undefined reference to `_Ux86_get_reg' :(.text+0xaf1a4): undefined reference to `_Ux86_step' collect2: error: ld returned 1 exit status Makefile.perf:350: recipe for target '~/perf' failed make[1]: *** [~/perf] Error 1 Makefile:68: recipe for target 'all' failed make: *** [all] Error 2 This is because the remote libunwind library detected is not appended to EXTLIBS variable, which will be included between 'start-group' and 'end-group' when linking. The existing variable LIBUNWIND_LIBS is assigned to libs for local unwind, this patch introduces a new variable EXTLIBS_LIBUNWIND for storing remote libunwind libraries instead. Signed-off-by: He Kuang Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/r/1465988636-81502-1-git-send-email-hekuang@huawei.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/config/Makefile | 3 +++ 1 file changed, 3 insertions(+) diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile index 098874b99981..80018feb99c0 100644 --- a/tools/perf/config/Makefile +++ b/tools/perf/config/Makefile @@ -365,6 +365,7 @@ ifndef NO_LIBUNWIND $(call detected,CONFIG_LIBUNWIND_X86) CFLAGS += -DHAVE_LIBUNWIND_X86_SUPPORT LDFLAGS += -lunwind-x86 + EXTLIBS_LIBUNWIND += -lunwind-x86 have_libunwind = 1 endif @@ -372,6 +373,7 @@ ifndef NO_LIBUNWIND $(call detected,CONFIG_LIBUNWIND_AARCH64) CFLAGS += -DHAVE_LIBUNWIND_AARCH64_SUPPORT LDFLAGS += -lunwind-aarch64 + EXTLIBS_LIBUNWIND += -lunwind-aarch64 have_libunwind = 1 $(call feature_check,libunwind-debug-frame-aarch64) ifneq ($(feature-libunwind-debug-frame-aarch64), 1) @@ -449,6 +451,7 @@ ifndef NO_LIBUNWIND CFLAGS += -DHAVE_LIBUNWIND_SUPPORT CFLAGS += $(LIBUNWIND_CFLAGS) LDFLAGS += $(LIBUNWIND_LDFLAGS) + EXTLIBS += $(EXTLIBS_LIBUNWIND) endif ifndef NO_LIBAUDIT