[PATCH 0/2] minor fixes to faddr2line

[PATCH 0/2] minor fixes to faddr2line

[Pankaj Raghav (Samsung)]

From: Pankaj Raghav <p.raghav@samsung.com>

The first commit fixes the issue I am facing in NixOS.

The second commit uses a tempfile instead of shell variable while trying
to read the elf file.

Pankaj Raghav (2):
  scripts/faddr2line:use /usr/bin/env bash for portability
  scripts/faddr2line:fix "Argument list too long" error

 scripts/faddr2line | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)


base-commit: 846bd2225ec3cfa8be046655e02b9457ed41973e
-- 
2.50.1

[PATCH 1/2] scripts/faddr2line:use /usr/bin/env bash for portability

[Pankaj Raghav (Samsung)]

From: Pankaj Raghav <p.raghav@samsung.com>

The shebang `#!/bin/bash` assumes a fixed path for the bash interpreter.
This path does not exist on some systems, such as NixOS, causing the
script to fail.

Replace `/bin/bash` with the more portable `#!/usr/bin/env bash`.

Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
---
 scripts/faddr2line | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/faddr2line b/scripts/faddr2line
index 1fa6beef9f97..966e98197dbf 100755
--- a/scripts/faddr2line
+++ b/scripts/faddr2line
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # SPDX-License-Identifier: GPL-2.0
 #
 # Translate stack dump function offsets.
-- 
2.50.1

[PATCH 2/2] scripts/faddr2line:fix "Argument list too long" error

[Pankaj Raghav (Samsung)]

From: Pankaj Raghav <p.raghav@samsung.com>

The run_readelf() function reads the entire output of readelf into a
single shell variable. For large object files with extensive debug
information, the size of this variable can exceed the system's
command-line argument length limit.

When this variable is subsequently passed to sed via `echo "${out}"`, it
triggers an "Argument list too long" error, causing the script to fail.

Fix this by redirecting the output of readelf to a temporary file
instead of a variable. The sed commands are then modified to read from
this file, avoiding the argument length limitation entirely.

Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
---
 scripts/faddr2line | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/scripts/faddr2line b/scripts/faddr2line
index 966e98197dbf..c8e341f8830e 100755
--- a/scripts/faddr2line
+++ b/scripts/faddr2line
@@ -107,14 +107,19 @@ find_dir_prefix() {
 
 run_readelf() {
 	local objfile=$1
-	local out=$(${READELF} --file-header --section-headers --symbols --wide $objfile)
+	local tmpfile
+	tmpfile=$(mktemp)
+
+	${READELF} --file-header --section-headers --symbols --wide "$objfile" > "$tmpfile"
 
 	# This assumes that readelf first prints the file header, then the section headers, then the symbols.
 	# Note: It seems that GNU readelf does not prefix section headers with the "There are X section headers"
 	# line when multiple options are given, so let's also match with the "Section Headers:" line.
-	ELF_FILEHEADER=$(echo "${out}" | sed -n '/There are [0-9]* section headers, starting at offset\|Section Headers:/q;p')
-	ELF_SECHEADERS=$(echo "${out}" | sed -n '/There are [0-9]* section headers, starting at offset\|Section Headers:/,$p' | sed -n '/Symbol table .* contains [0-9]* entries:/q;p')
-	ELF_SYMS=$(echo "${out}" | sed -n '/Symbol table .* contains [0-9]* entries:/,$p')
+	ELF_FILEHEADER=$(sed -n '/There are [0-9]* section headers, starting at offset\|Section Headers:/q;p' "$tmpfile")
+	ELF_SECHEADERS=$(sed -n '/There are [0-9]* section headers, starting at offset\|Section Headers:/,$p' "$tmpfile" | sed -n '/Symbol table .* contains [0-9]* entries:/q;p')
+	ELF_SYMS=$(sed -n '/Symbol table .* contains [0-9]* entries:/,$p' "$tmpfile")
+
+	rm -f -- "$tmpfile"
 }
 
 check_vmlinux() {
-- 
2.50.1

Re: [PATCH 0/2] minor fixes to faddr2line

[Pankaj Raghav]

On 9/21/25 12:03, Pankaj Raghav (Samsung) wrote:
> From: Pankaj Raghav <p.raghav@samsung.com>
> 
> The first commit fixes the issue I am facing in NixOS.
> 
> The second commit uses a tempfile instead of shell variable while trying
> to read the elf file.
> 
> Pankaj Raghav (2):
>   scripts/faddr2line:use /usr/bin/env bash for portability
>   scripts/faddr2line:fix "Argument list too long" error
> 
>  scripts/faddr2line | 15 ++++++++++-----
>  1 file changed, 10 insertions(+), 5 deletions(-)
> 

Gentle ping Josh :)

--
Pankaj

Re: [PATCH 0/2] minor fixes to faddr2line

[Josh Poimboeuf]

On Sun, Sep 21, 2025 at 12:03:56PM +0200, Pankaj Raghav (Samsung) wrote:
> From: Pankaj Raghav <p.raghav@samsung.com>
> 
> The first commit fixes the issue I am facing in NixOS.
> 
> The second commit uses a tempfile instead of shell variable while trying
> to read the elf file.
> 
> Pankaj Raghav (2):
>   scripts/faddr2line:use /usr/bin/env bash for portability
>   scripts/faddr2line:fix "Argument list too long" error
> 
>  scripts/faddr2line | 15 ++++++++++-----
>  1 file changed, 10 insertions(+), 5 deletions(-)

Queued, thanks!

-- 
Josh