linux-yocto/scripts/faddr2line
Srikar Dronamraju 2d77de1581 scripts/faddr2line: Fix regression in name resolution on ppc64le
Commit 1d1a0e7c51 ("scripts/faddr2line: Fix overlapping text section
failures") can cause faddr2line to fail on ppc64le on some
distributions, while it works fine on other distributions. The failure
can be attributed to differences in the readelf output.

  $ ./scripts/faddr2line vmlinux find_busiest_group+0x00
  no match for find_busiest_group+0x00

On ppc64le, readelf adds the localentry tag before the symbol name on
some distributions, and adds the localentry tag after the symbol name on
other distributions. This problem has been discussed previously:

  https://lore.kernel.org/bpf/20191211160133.GB4580@calabresa/

This problem can be overcome by filtering out the localentry tags in the
readelf output. Similar fixes are already present in the kernel by way
of the following commits:

  1fd6cee127 ("libbpf: Fix VERSIONED_SYM_COUNT number parsing")
  aa915931ac ("libbpf: Fix readelf output parsing for Fedora")

[jpoimboe: rework commit log]

Fixes: 1d1a0e7c51 ("scripts/faddr2line: Fix overlapping text section failures")
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Link: https://lore.kernel.org/r/20220927075211.897152-1-srikar@linux.vnet.ibm.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
2022-11-16 10:42:10 +01:00

8.3 KiB
Executable File

#!/bin/bash

SPDX-License-Identifier: GPL-2.0

Translate stack dump function offsets.

addr2line doesn't work with KASLR addresses. This works similarly to

addr2line, but instead takes the 'func+0x123' format as input:

$ ./scripts/faddr2line ~/k/vmlinux meminfo_proc_show+0x5/0x568

meminfo_proc_show+0x5/0x568:

meminfo_proc_show at fs/proc/meminfo.c:27

If the address is part of an inlined function, the full inline call chain is

printed:

$ ./scripts/faddr2line ~/k/vmlinux native_write_msr+0x6/0x27

native_write_msr+0x6/0x27:

arch_static_branch at arch/x86/include/asm/msr.h:121

(inlined by) static_key_false at include/linux/jump_label.h:125

(inlined by) native_write_msr at arch/x86/include/asm/msr.h:125

The function size after the '/' in the input is optional, but recommended.

It's used to help disambiguate any duplicate symbol names, which can occur

rarely. If the size is omitted for a duplicate symbol then it's possible for

multiple code sites to be printed:

$ ./scripts/faddr2line ~/k/vmlinux raw_ioctl+0x5

raw_ioctl+0x5/0x20:

raw_ioctl at drivers/char/raw.c:122

raw_ioctl+0x5/0xb1:

raw_ioctl at net/ipv4/raw.c:876

Multiple addresses can be specified on a single command line:

$ ./scripts/faddr2line ~/k/vmlinux type_show+0x10/45 free_reserved_area+0x90

type_show+0x10/0x2d:

type_show at drivers/video/backlight/backlight.c:213

free_reserved_area+0x90/0x123:

free_reserved_area at mm/page_alloc.c:6429 (discriminator 2)

set -o errexit set -o nounset

usage() { echo "usage: faddr2line [--list]