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authorKim Phillips <kim.phillips@arm.com>2017-12-14 17:52:42 -0600
committerArnaldo Carvalho de Melo <acme@redhat.com>2017-12-27 12:15:58 -0300
commitf1031c8d33a8c40d4cac26e58c37d9fba0e31a8a (patch)
tree6c0660697eec4a473260172509da2fda9e3f832a /tools/perf/arch
parentca8000684ec4e66f965e1f9547a3c6cb834154ca (diff)
downloadlinux-f1031c8d33a8c40d4cac26e58c37d9fba0e31a8a.tar.bz2
perf probe arm64: Fix symbol fixup issues due to ELF type
On an arm64 machine running a CONFIG_RANDOMIZE_BASE=y kernel, perf kernel symbol resolution fails. Debugging saw symsrc_init calling the default elf__needs_adjust_symbols() where checks for an ET_DYN (3) ehdr.e_type failed when they should have succeeded. Fix by adopting powerpc version of the weak elf__needs_adjust_symbols() function, as done in commit d2332098331f ("perf probe ppc: Fix symbol fixup issues due to ELF type"). Prior to this patch, perf test 1 would fail: $ sudo oldperf test -v 1 |& head 1: vmlinux symtab matches kallsyms : test child forked, pid 33374 Looking at the vmlinux_path (8 entries long) Using /usr/lib/debug/boot/vmlinux for symbols ERR : 0xfffe0000100f1000: do_undefinstr not on kallsyms ERR : 0xfffe0000100f1320: do_sysinstr not on kallsyms ERR : 0xfffe0000100f13b0: do_debug_exception not on kallsyms ERR : 0xfffe0000100f1498: do_mem_abort not on kallsyms ERR : 0xfffe0000100f1580: do_sp_pc_abort not on kallsyms ... After applying this patch, perf test 1 now succeeds: $ sudo ./newperf test -v 1 |& head 1: vmlinux symtab matches kallsyms : test child forked, pid 33378 Looking at the vmlinux_path (8 entries long) Using /usr/lib/debug/boot/vmlinux for symbols WARN: 0xffff000008081000: diff name v: do_undefinstr k: __exception_text_start WARN: 0xffff0000080819e8: diff name v: __irqentry_text_end k: __softirqentry_text_start WARN: 0xffff000008081d08: diff name v: __entry_text_start k: __softirqentry_text_end WARN: 0xffff00000809db5c: diff name v: flush_icache_range k: __flush_cache_user_range WARN: 0xffff000008101908: diff name v: sys_ni_syscall k: sys_vm86old ... Signed-off-by: Kim Phillips <kim.phillips@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/20171214175242.e30450f17f93ad675d968fa3@arm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/arch')
-rw-r--r--tools/perf/arch/arm64/util/Build1
-rw-r--r--tools/perf/arch/arm64/util/sym-handling.c22
2 files changed, 23 insertions, 0 deletions
diff --git a/tools/perf/arch/arm64/util/Build b/tools/perf/arch/arm64/util/Build
index b1ab72d2a42e..e04f6cdd6f32 100644
--- a/tools/perf/arch/arm64/util/Build
+++ b/tools/perf/arch/arm64/util/Build
@@ -1,4 +1,5 @@
libperf-y += header.o
+libperf-y += sym-handling.o
libperf-$(CONFIG_DWARF) += dwarf-regs.o
libperf-$(CONFIG_LOCAL_LIBUNWIND) += unwind-libunwind.o
diff --git a/tools/perf/arch/arm64/util/sym-handling.c b/tools/perf/arch/arm64/util/sym-handling.c
new file mode 100644
index 000000000000..0051b1ee8450
--- /dev/null
+++ b/tools/perf/arch/arm64/util/sym-handling.c
@@ -0,0 +1,22 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * Copyright (C) 2015 Naveen N. Rao, IBM Corporation
+ */
+
+#include "debug.h"
+#include "symbol.h"
+#include "map.h"
+#include "probe-event.h"
+#include "probe-file.h"
+
+#ifdef HAVE_LIBELF_SUPPORT
+bool elf__needs_adjust_symbols(GElf_Ehdr ehdr)
+{
+ return ehdr.e_type == ET_EXEC ||
+ ehdr.e_type == ET_REL ||
+ ehdr.e_type == ET_DYN;
+}
+#endif