From 1e4bd2ae4564adbf9f9b6d26fad65ddabd0147fc Mon Sep 17 00:00:00 2001 From: Nick Gasson <nick.gasson@arm.com> Date: Thu, 28 May 2020 13:19:16 +0800 Subject: [PATCH] perf jit: Fix inaccurate DWARF line table Fix an issue where addresses in the DWARF line table are offset by -0x40 (GEN_ELF_TEXT_OFFSET). This can be seen with `objdump -S` on the ELF files after perf inject. Committer notes: Ian added this in his Acked-by reply: --- Without too much knowledge this looks good to me. The original code came from oprofile's jit support: https://sourceforge.net/p/oprofile/oprofile/ci/master/tree/opjitconv/debug_line.c#l325 --- Signed-off-by: Nick Gasson <nick.gasson@arm.com> Acked-by: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lore.kernel.org/lkml/20200528051916.6722-1-nick.gasson@arm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> --- tools/perf/util/genelf_debug.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/genelf_debug.c b/tools/perf/util/genelf_debug.c index 30e9f618f6cd..dd40683bd4c0 100644 --- a/tools/perf/util/genelf_debug.c +++ b/tools/perf/util/genelf_debug.c @@ -342,7 +342,7 @@ static void emit_lineno_info(struct buffer_ext *be, */ /* start state of the state machine we take care of */ - unsigned long last_vma = code_addr; + unsigned long last_vma = 0; char const *cur_filename = NULL; unsigned long cur_file_idx = 0; int last_line = 1; @@ -473,7 +473,7 @@ jit_process_debug_info(uint64_t code_addr, ent = debug_entry_next(ent); } add_compilation_unit(di, buffer_ext_size(dl)); - add_debug_line(dl, debug, nr_debug_entries, 0); + add_debug_line(dl, debug, nr_debug_entries, GEN_ELF_TEXT_OFFSET); add_debug_abbrev(da); if (0) buffer_ext_dump(da, "abbrev");