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linux-yocto/scripts/faddr2line
Carlos Llamas 3773d35c7f Revert "scripts/faddr2line: Check only two symbols when calculating symbol size" 
[ Upstream commit 56ac7bd2c58a4e93d19f0ccb181035d075b315d3 ]

This reverts commit c02904f05f.

Such commit assumed that only two symbols are relevant for the symbol
size calculation. However, this can lead to an incorrect symbol size
calculation when there are mapping symbols emitted by readelf.

For instance, when feeding 'update_irq_load_avg+0x1c/0x1c4', faddr2line
might need to process the following readelf lines:

 784284: ffffffc0081cca30   428 FUNC    GLOBAL DEFAULT     2 update_irq_load_avg
  87319: ffffffc0081ccb0c     0 NOTYPE  LOCAL  DEFAULT     2 $x.62522
  87321: ffffffc0081ccbdc     0 NOTYPE  LOCAL  DEFAULT     2 $x.62524
  87323: ffffffc0081ccbe0     0 NOTYPE  LOCAL  DEFAULT     2 $x.62526
  87325: ffffffc0081ccbe4     0 NOTYPE  LOCAL  DEFAULT     2 $x.62528
  87327: ffffffc0081ccbe8     0 NOTYPE  LOCAL  DEFAULT     2 $x.62530
  87329: ffffffc0081ccbec     0 NOTYPE  LOCAL  DEFAULT     2 $x.62532
  87331: ffffffc0081ccbf0     0 NOTYPE  LOCAL  DEFAULT     2 $x.62534
  87332: ffffffc0081ccbf4     0 NOTYPE  LOCAL  DEFAULT     2 $x.62535
 783403: ffffffc0081ccbf4   424 FUNC    GLOBAL DEFAULT     2 sched_pelt_multiplier

The symbol size of 'update_irq_load_avg' should be calculated with the
address of 'sched_pelt_multiplier', after skipping the mapping symbols
seen in between. However, the offending commit cuts the list short and
faddr2line incorrectly assumes 'update_irq_load_avg' is the last symbol
in the section, resulting in:

  $ scripts/faddr2line vmlinux update_irq_load_avg+0x1c/0x1c4
  skipping update_irq_load_avg address at 0xffffffc0081cca4c due to size mismatch (0x1c4 != 0x3ff9a59988)
  no match for update_irq_load_avg+0x1c/0x1c4

After reverting the commit the issue is resolved:

  $ scripts/faddr2line vmlinux update_irq_load_avg+0x1c/0x1c4
  update_irq_load_avg+0x1c/0x1c4:
  cpu_of at kernel/sched/sched.h:1109
  (inlined by) update_irq_load_avg at kernel/sched/pelt.c:481

Fixes: c02904f05f ("scripts/faddr2line: Check only two symbols when calculating symbol size")
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-05 14:01:21 +01:00

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#!/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]