mirror of https://gitee.com/openkylin/linux.git
b93b096782
Perf tool fails to unwind user stack if the event raises in a shared object. This patch improves tests/dwarf-unwind.c to demonstrate the problem by utilizing commonly used glibc function "bsearch". If perf is not statically linked, the testcase will try to unwind a mixed call trace. By debugging libunwind I found that there is a bug in unwind-libunwind: it always passes 0 as segbase to libunwind, cause libunwind unable to locate debug_frame entry fir first level ip address (I add some more debugging output into libunwind to make things clear): >_Uarm_dwarf_find_debug_frame: start_ip = 10be98, end_ip = 10c2a4 >_Uarm_dwarf_find_debug_frame: found debug_frame table `/lib/libc-2.18.so': segbase=0x0, len=7, gp=0x0, table_data=0x449388 >_Uarm_dwarf_search_unwind_table: call lookup:ip = b6cd3bcc, segbase = 0, rel_ip = b6cd3bcc >lookup: e->start_ip_offset = bcf18 (rel_ip = b6cd3bcc) >lookup: e->start_ip_offset = 6d314 (rel_ip = b6cd3bcc) >lookup: e->start_ip_offset = 33d0c (rel_ip = b6cd3bcc) ... >lookup: e->start_ip_offset = 15d0c (rel_ip = b6cd3bcc) >lookup: e->start_ip_offset = 15c40 (rel_ip = b6cd3bcc) >_Uarm_dwarf_search_unwind_table: IP b6cd3bcc inside range b6c12000-b6d4c000, but no explicit unwind info found >put_rs_cache: unmasking signals/interrupts and releasing lock >_Uarm_dwarf_step: returning -10 >_Uarm_step: dwarf_step()=-10 This patch passes map->start as segbase to dwarf_find_debug_frame(), so di will be initialized correctly. In addition, dso and executable are different when setting segbase. This patch first check whether the elf is executable, and pass segbase only for shared object. Signed-off-by: Wang Nan <wangnan0@huawei.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Li Zefan <lizefan@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1421203007-75799-1-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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.. | ||
attr | ||
attr.c | ||
attr.py | ||
bp_signal.c | ||
bp_signal_overflow.c | ||
builtin-test.c | ||
code-reading.c | ||
dso-data.c | ||
dwarf-unwind.c | ||
evsel-roundtrip-name.c | ||
evsel-tp-sched.c | ||
fdarray.c | ||
hists_common.c | ||
hists_common.h | ||
hists_cumulate.c | ||
hists_filter.c | ||
hists_link.c | ||
hists_output.c | ||
keep-tracking.c | ||
make | ||
mmap-basic.c | ||
mmap-thread-lookup.c | ||
open-syscall-all-cpus.c | ||
open-syscall-tp-fields.c | ||
open-syscall.c | ||
parse-events.c | ||
parse-no-sample-id-all.c | ||
perf-record.c | ||
perf-targz-src-pkg | ||
perf-time-to-tsc.c | ||
pmu.c | ||
python-use.c | ||
rdpmc.c | ||
sample-parsing.c | ||
sw-clock.c | ||
switch-tracking.c | ||
task-exit.c | ||
tests.h | ||
thread-mg-share.c | ||
vmlinux-kallsyms.c |