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60fd39af33
Mapping symbols emitted in the readelf output can confuse the
'faddr2line' symbol size calculation, resulting in the erroneous
rejection of valid offsets. This is especially prevalent when building
an arm64 kernel with CONFIG_CFI_CLANG=y, where most functions are
prefixed with a 32-bit data value in a '$d.n' section. For example:
447538: ffff800080014b80 548 FUNC GLOBAL DEFAULT 2 do_one_initcall
104: ffff800080014c74 0 NOTYPE LOCAL DEFAULT 2 $x.73
106: ffff800080014d30 0 NOTYPE LOCAL DEFAULT 2 $x.75
111: ffff800080014da4 0 NOTYPE LOCAL DEFAULT 2 $d.78
112: ffff800080014da8 0 NOTYPE LOCAL DEFAULT 2 $x.79
36: ffff800080014de0 200 FUNC LOCAL DEFAULT 2 run_init_process
Adding a warning to do_one_initcall() results in:
| WARNING: CPU: 0 PID: 1 at init/main.c:1236 do_one_initcall+0xf4/0x260
Which 'faddr2line' refuses to accept:
$ ./scripts/faddr2line vmlinux do_one_initcall+0xf4/0x260
skipping do_one_initcall address at 0xffff800080014c74 due to size mismatch (0x260 != 0x224)
no match for do_one_initcall+0xf4/0x260
Filter out these entries from readelf using a shell reimplementation of
is_mapping_symbol(), so that the size of a symbol is calculated as a
delta to the next symbol present in ksymtab.
Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20231002165750.1661-4-will@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
8.6 KiB
Executable File
8.6 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]